ICPTT 2011: Sustainable Solutions For Water, Sewer, Gas, And Oil Pipelines

Surcharge and even sewer system overflow (SSO) have been considered as the major issues threatening the discharge security in plain areas of the south of China. To determine the hydraulic performance and defects within the test drainage area, an integrated application platform was developed, which incorporates on-line flow monitoring and hydraulic modeling into Geographic Information System (GIS) A drainage network model of the sewerage system was constructed by using Storm Water Management Model (SWMM) to predict responses under the current condition. A flow monitoring program was established to obtain accurate current flow rates during dry/wet weather conditions, in an attempt to characterize the flow and to calibrate the model. A trunk pipe and two typical outlets, residential and mixed, were selected as gauging sites. The monitor program found that the depth of the trunk pipe with diameter of 1.2m was always from 1.5m to 4m, which was very hazardous to sewer systems. However, the modeling results showed that, under the condition without sediment in pipes, the existing sewer system had enough capacity to transport the monitored wastewater, and the average depth ratio in pipes was no more than 70%. Due to the limited pipe slope, the velocity was only kept at 0.3 m/s to 0.9m/s. Therefore, the sewer system could suffer from sediment deposition easily, which was evidenced by the monitoring program. Besides, inefficient pump control and significant inflow and infiltration (II) in wet weather were identified as reasons leading to surcharge. The integrated application provided reliable and supportive data for the control optimization and rehabilitation of the sewer system.

The horizontal guidance trenchless towing pipe technology has been increasingly used in heating engineering because of its high efficiency, safety feature. The heating pipeline bears not only inner pressure load, soil load and transportation load, but also alternation temperature load which is larger than inner pressure load. Remarkably, the pipeline will emerge big fold angle when the towing pipe is connected with the directly buried pipeline that already exists. In order to prevent the fold pipe from damage, compensator is usually used to protect the pipe with big fold angle. ANSYS is used to simulate directly buried heating pipe with 12° fold angles for pipe size DN400 in this paper. Different curvature radius elbows are used to replace big fold angle pipe separately and the compensator near the big fold angle is canceled in the numerical simulation. Result shows that elbows with proper curvature radius can not only satisfy the fatigue strength, reduce construction difficulty and costs, but also increase the reliability of the buried pipeline. This paper provides theory basis for the trenchless towing pipe technology application in the heating industry.

With the increasing of the rate of gasification and the number of consumers, some of the city gas distribution pipeline networks' pipe diameter is too small and lack of gas capacity. Obviously, it leads to the gas shortage in the regions which are far away from the gas resources when the supply summit comes, and it becomes the "bottleneck" of the whole gas-line system. Therefore, it is necessary to analyze the adaptability of the distribution pipeline network based on the gas requirements to find the "bottleneck" of the whole gas-line system. Based on the investigation of the change of pressure of the pipeline and the node, the thesis combines the calculation sub-model of the pipeline and the node with the gas-line diameter changing sub-model and the calculation sub-model of the network pressure. With reference to the analysis of the changeable pressure of the stable hydraulic calculations of several real pipes, it establishes the fault propagation model of the hydraulic conditions for city gas distribution pipeline networks. The model can effectively inspect the change of pressure resulting from the limited diameter, find the pipe which the pipe diameter is too small exactly and offer important of evidence to the reconstruction of the networks.

The layout of city pipelines is usually called a pipe network. In order to evaluate the seismic resistance of a pipe network, the source to terminal (s-t) reliability algorithm is mostly used. The exact reliability computation method of s-t problem is extremely time-consuming. It is, as an algorithmic problem, classed in the NP hard family. For a large pipe network, approximate computation methods are generally attractive. One feasible approximation approach is to use bounds, and another is to use simulation. This paper presents a directly disjoint algorithm using bounds for seismic reliability evaluation of pipe networks. Based on the principle of breadth-first search and minimal-distance-first search, the proposed algorithm could obtain exact solution of simple networks and approximation of large networks with real-time accumulation of disjoint minimal paths and cuts. Compared with the Modified Dotson algorithm, this algorithm is faster in solving the connective reliability of pipeline network with low element operation probability. Compared with the Minimal Cut-Based Recursive Decomposition algorithm, a more optimum disjoint set can be solved by this algorithm. At the end of this paper, the proposed algorithm was used to estimate the seismic reliability of a water supply network.

In recent years, the rising trend of energy consumption of northeastern crude oil pipeline network in China is receiving considerable attention. Through collecting fundamental information about the main energy-consumption equipments and analyzing operating reports of pipelines, we find three bottlenecks which influence the energy-consumption level for crude oil pipelines seriously. Then a new energy consumption analysis method for crude oil pipelines is presented, including safety assessment of transportation oil temperature, optimization of process operation schemes and energy-consumption equipments transformation. Based on the above energy consumption analysis method for oil pipelines, we formulate the optimal steady operation schemes for the main pipelines in northeastern crude oil pipeline network and assess their energy-consumption grade.

The lifecycle model of water distribution systems goes through three periods: early failure period, random failure period and serious failure period. It also includes the prediction model of bursting and leakage frequency, the optimal model of detection interval and the optimal model of scheduling pipe replacement. By investigating the historical data of leakage and age of the pipe network, "bathtub curve" representing the relationship of leakage frequent against age is built and used to predict leakage frequency of pipe network. By combining the pipe break rate prediction model and the extreme pipe break rate model, the prediction model for water pipe replacement time and the determination method for optimal replacement time were set up. Based on the prediction of water loss and the incorporation of present value cost, an optimal model of detection interval is established by analyzing the cost of water loss and leakage control.

Because of inhomogeneous settlement of ground and rainfall erosion, buried pipeline will be exposed and unsupported during its normal used stage. According to this unsupported state, oil pipeline which is buried under earth is built as space shell model of finite element to analyze its stresses and deformation. Security criteria of strength and stiffness under normal used state are presented. Based on security criteria, limited spans for pipe's security use are determined when one, two and many sites are unsupported. Meanwhile supported plans are presented to ensure pipeline security under normal used state.

ASME B31G is the most basic and widespread method which enables to assess the remaining strength of corroded pipelines. ASME B31G-2009 is the third edition of B31G which is the newest revision approved by the American National Standards Institute (ANSI). This paper comprehensively introduced the development process of ASME B31G, and do some comparative studies with other standards of RSTRENG 0.85 dL and DNV RP - F101 which are also widely used in assessment the remaining strength of corroded pipelines. The predicted failure pressure are calculated for each standard mentioned above, based on 35 groups datum of pipe full-size blasting test collected form several literatures, and express the deviation between the forecasted value and the real datum quantificational by charts. Finally, safety criterion, applicable defects types, the strength grade of pipe and so on are analyzed and compared among the assessment methods. The investments showed that ASME B31G-2009 is much more greatly improved than previous editions of B31G; the conservative properties of ASME B31G-2009 and RSTRENG 0.85 dL are both much lower. They have effectively improved the pipe conveying efficiency and optimized the cost efficiency. However, they are both only applicable to evaluate the medium and low strength steel pipes. Inversely, NV RP-F101 is applicable to the medium and high strength steel pipes. Its results are often not safe to the lower strength steel pipes.

In view of the corrosion status of buried oil pipelines in an oil field, the corrosion mechanisms of pipelines are investigated and some related influencing factors are analyzed. The influence of temperature and different ion concentrations for the corrosion behavior in buried pipelines is studied by using orthogonal experimental design method. Furthermore, the anticorrosion reagent ingredients are studied indoor, and the suitable reagent system is optimized out from anticorrosion technology system. The results show that the primary and secondary order of factors which affect pipeline corrosion is temperature, Cl^– ion concentration, HCO₃^– ion concentration, SO₄^2– ion concentration, Ca²⁺ ion concentration and Mg²⁺ ion concentration, in which temperature and Cl^2– ion concentration are both main factors. On this base, the anticorrosion system is screened out which mainly consists of the KL-601 improved corrosion inhibitor, and the dynamic tracking evaluations of the anticorrosion effect are studied by a chemical tracer technique. Then the protection period is optimized, which can create considerable economic benefits. This study has certain guidance for selecting suitable pipeline material and anticorrosion measure to extend pipeline life and reduce losses.

As the main source gas reservoir of the West to East Gas Pipeline Project, the Yaha Gas Condensate Field was a condensate gas reservoir located in the Tarim basin in the northwestern China that started to supply gas in 2000. The gas produced by the field contained about 0.7–1.3 volume percent CO₂ and Clion concentration as much as 116,000ppm. Initially, 16Mn steel was adopted to construct the pipelines. By May of 2006, there were as many as fifty failures. The investigations on corrosion of flow line at simulated internal service conditions found the high corrosion rate was due to the multiphase flow induced erosion and CO₂ corrosion. Considering severe corrosion environments in the Yaha Gas Condensate Field, bimetallic lined pipes, with a liner pipes made of CRA and an outer pipes made of low-cost steel, might be a potential anticorrosion solution. In this paper, the outcome of a comprehensive program of work to establish suitability of bimetallic lined pipe for gathering lines in Yaha Gas Condensate Field was presented. Manufacturing technique of bimetallic lined pipe, assessment of girth welding procedure, corrosion performance in the simulated condition and analysis on economics advantages of bimetal lined pipe were all discussed. Fit-for-purpose analysis showed that bimetal lined pipes could be an economic and effective solution to the corrosion problem in the Yaha Gas Condensate Field.

The accurate prediction of corrosion rate is significant for the safe operation of oil-gas gathering pipeline. The internal corrosion of pipeline is a multivariable nonlinear system, and furthermore because of the complex mapping relation between corrosion rate and its influencing factors, it is always difficult to predict the corrosion rate accurately. Aiming this problem, this paper established a wavelet neural network (WNN) and introduced genetic algorithm (GA) to optimize it. Taking one gathering pipeline in gas field as an example, prediction model of internal corrosion rate for gas pipeline was built by using corrosion factors (CO₂ content, temperature, etc.) as input parameters and internal corrosion rate as output parameter. The model combines the global optimization searching performance of the genetic algorithm and the well time-frequency localization of the wavelet neural network, so it has higher learning accuracy and faster convergence rate. Prediction results fit simulating test data preferably. It indicates that GA-WNN model has high fitting accuracy. Results proved it should be a good tool to predict internal corrosion rate of gathering pipeline.

Gathering pipeline failure has been detected in a gas field in western of China in 2009. It presents that corrosion predication and control is a key problem to avoid frequently excavating. Therefore, corrosion of 20G, 20#, 15CrMo and 16Mn steels in the stimulated environment were investigated in order to evaluate corrosion risk of the buried pipeline and design the new pipeline. The influence of environmental factors to the materials was discovered by orthogonal experiment. It is found that temperature, pH, HCO3₃^– and Cl^– are the most important factors though their subsequences are difference for the four steels. The electrochemical method, XRD and SEM were used to provide evidences to the corrosion difference. Corrosion monitoring is designed on the basis of the laboratory results. And the principle of materials selection is scheduled by considering the corrosion resistance and economical management target.

Drinking water in water distribution system can be fully contact with pipe wall, and generate second pollutant through a complex biochemical process. Confirming effects of the pipelines on water quality and existence of the health risks plays an important guiding role in controlling water quality secondary pollution. This paper, made by laboratory test and in-situ measurement, compares the changes of TOC, turbidity, chroma, total bacterial count, toxic metal and other related parameters in pipelines, with which different materials, age and corrosion protection ways. Analyze in detail the effects of material and age on water quality in pipelines. The data shows that water quality in non-metal pipelines is more stable than in metal pipelines. Whether non-metal pipelines or metal pipelines, with the time lapses, would have an increasing effect on water quality. Base on this, we put forward some measures to control water pollution in pipelines. Pointing out that toxicological and microbiological testing combined with the rational choices of anticorrosion scheme is the efficient way to ensure quality of water in pipelines.

Corrosion is one of the basic affecting factors that make metal-pipe disabled, and is under the influence of many factors. But it is hard to accurately get each factor's value, and dispersion and randomness of statistical data make it hard to apply traditional method in date processing, too. Projection Pursuit Method is an objective evaluation method. It, uninfluenced by human factors, entirely depends on the mathematic principle and considers index's correlation. In the paper Projection Pursuit Method is applied to evaluate soil corrosion of X70 pipeline from Changyang to Wuhan. Real-coded Accelerating Genetic Algorithm (RAGA) is utilized to optimize the projection direction of Projection Pursuit clustering (PPC) model, and multi-dimension data is transformed to low dimension subspace. Each index of factors is evaluated based on pursuing optimal projection direction and projection value. Then based on the above the optimal projection direction, weight vector can be calculated which objectively reflects the index's correlation. We can rank weight vector in order from big to small, and the results show that the soil electrochemistry property factors of corroding the X70 pipeline are CL^–, SO₄^2–, soil resistivity, HCO₃^–, pH value and volumetric moisture content in turn.

Although the alternating current (AC) may cause corrosion on coated pipelines even when cathodic protection is applied, but experimental studies proved that impressed current cathodic protection system could have effectiveness to mitigate AC corrosion, if the protection potential has been selected correctly. The effect of AC interference on cathodic protection system was studied with a laboratory simulation device. Electrochemical experiments were used to characterize and quantify the AC corrosion of X70 steel under different protected potential. The polarization experiment results proved that protection voltage of –650mV to –1100mV may play a protective role. According to the electrochemical impedance spectroscopy (EIS) analysis of X70 steel with different AC interferences in soil environments, the corresponding equivalent circuits were proposed respectively. Based on EIS results, the R_t-E_e,c curves are obtained, from which the optimum protection potential of X70 steel in soil solution can be determined.

High-pressure nonmetal has good corrosion resistance, but also has significantly different steel based performance parameters. Based on the Von Mises yield criterion material nonlinearity, ideal elastic-plastic stress-strain relations and bilinear servo aggrandizement criterion, nonmetal pipeline load-bearing finite element analysis model has been established by using Shell 99 unit, COMBIN14 spring unit, Solid46 unit. And choose a big deformation analysis model, revised Newton- Raphson method to solve the incremental balance equation in an iteration way. The experimental measurement error for 41MPa rupture pressure compared is 3.21%, which indicates that the established finite element model and the solving method are correct and reasonable.

Stray current interference may cause pipeline corrosion, which will result in premature failure of pipeline and potential safety problem to the persons who would touch the pipe during the work. The results of systematic field survey of the AC interference on an oil products pipeline showed that the range of quasi-stable AC interference was more than 20 km. Moreover, the risk of two separate pipeline sections among them was medium or worse. The relationship among corrosion rate, AC interference voltage, and AC interference current density was summarized after on-site tests. Finally, some mitigation suggestions were proposed.

Soil stress corrosion crack (SCC) is one of the major hazard factor that cause the failure of buried piping. This paper analyzed influence factors and pipeline failure mode of soil SCC; introduced the progress of soil SCC study; presented the test method and the criterion of soil SCC; and analyzed soil SCC sensitive of typical soil from Shan-jing pipeline 1#. It have very important reference value for similar research.

The mechanical properties and creep characteristic parameters of bedded rock salt were obtained by uniaxial and triaxial tests stimulating underground conditions. The bedded rock salt samples used in the experiments were got from H-10 well of a salt cavern gas storage in China. The "casing-cement-rock salt" numerical model was established to calculate the external pressure subjected to completion casing in bedded rock salt formation. Basing on the model, the influences of formation dip, interlayer friction coefficient, and creep time on the casing stresses and deformations were studied. The calculated results show that the external pressures are related to the angle between principal stress, location, and creep time. The maximum external pressure produced by creep is larger about 10% than in-situ stress. When the formation dip is smaller than about 50°, the stresses and deformations of casing increase with the formation dips, and which achieve the maximum at about 50°, and then decrease. The stresses and deformations decrease as the increase of interlayer friction coefficient.

The load-bearing capacity of the casing threaded connection decreases notably as the non-uniform forces acting on each thread under tensile load. The analytical and finite element methods are discussed to study the load distribution of premium threaded. Firstly, the physical-mechanical model and the deformation-compatibility equation are established for the thread teeth meshing of casing connection, and then the theory and formulas of the inhomogeneous load distribution in casing thread are obtained. Secondly, according to the structure parameters and the load characteristics of VAM TOP casing connection, a finite element model for contact problems of casing thread meshing is established with the elastoplastic FEM. Then the contact stress of the tooth tip, flank and root are calculated by using the ANSYS software. Finally, the analytical values of load distribution are compared with the finite element values, and then the results show that the load formulas can be used in inhomogeneous load distribution analysis of the premium threaded casing connection.

Through analyzing different guidelines and standards for material selection of OCTG in sour conditions, belonging to six companies in four countries, we generalized the main factors that influence the material selection of OCTG. Based on integrating and optimizing these six guidelines on the materials' safety and corrosion resistance properties, a synthetic method for selecting materials has been brought forward. And further, software for material selection of OCTG in sour conditions has been developed. This software can provide results of six widely used materials selection guidelines of Sumitomo, NKK, Kawasaki, Lonestar, DMV and Cabval, and meanwhile, the best solution can be provided by the synthetic module. The East Sichuan region has been taken for example. Input the environmental parameters and then the results of different guidelines and suggested one are obtained. By comparing them with recommended and adopted materials for well completion, it demonstrates that the results provided by the software are accurate and reliable.

Wall thickness, yield strength, elastic modulus, internal pressure, outer diameter, and other parameters of oil/gas pipelines are within uncertainty and meet certain distributions. These parameters have significant influences on the safety and reliability of pipelines. According to the actual pipeline stress state and the distribution of above parameters, finite element models of safety and reliability of pipeline were established in the paper. The semi-analytical method was introduced to the traditional Monte Carlo method, which greatly reduced the sampling frequency and improved the efficiency of numerical simulation. We took a simulation calculation on the reliability of certain pipeline of the West-East natural gas transmission project using this method, researched the influence of wall thickness, yield strength, elastic modulus, internal pressure, outer diameter and other parameters on the reliability of a pipe, gave the corresponding relationship between the reliability index and ultimate stress. The results show that, introduce the semi-analytical method to Monte Carlo method can effectively improve the simulation efficiency of pipelines' reliability. The variation coefficient of yield strength, internal pressure, wall thickness and elastic modulus have significant influence on pipelines' reliability. When the variation coefficient is comparatively large, the overall reliability of pipeline is comparatively low, so we recommend strictly control the deviation of each parameter in actual process of design and operation of pipelines.

In order to get the quantitative relationship between the residual collapse pressure of casing and the build-up rate of bend part in horizontal wells, by theoretical analysis and finite element simulation method, we analyze residual collapse pressure of casing of three different diameters under the bending load and the outer pressure. The results show that casing cross-section roundness caused by bending has little effect on residual collapse pressure. The relationship between residual collapse pressure and build-up rate of bend part is the second inverse relationship. When the build-up rate of wellbore is the same, the relationship between residual collapse pressure of casing and the rate of diameter to thickness is inverse exponential relationship. The research provides a design reference for the collapse pressure of bend part casing in medium/short radius horizontal wells.

The loads subjected to completion casing of salt cavern gas storage is relatively complex, including internal and external pressures, creep loads, and axial forces, etc. Furthermore, these loads, dimensions, and properties of casing are random values and obey some distribution rules. It makes the traditional strength calculating methods are disable to accurately getting the stresses of casing and impossible predicting the randomicity of various factors on casing safety. The probability theory is proposed in the paper to obtain the reliability of completion casing in salt cavern gas storage. The randomicity of dimensions and properties of casing, cement sheath, and rock salt are also studied. The 3-D stochastic numerical simulation models of casing-cement-rock salt are established by ANSYS software. And the reliability of casing is obtained by introducing Monte Carlo Latin — Hypercube method into the numerical models. The influence factors on the reliability of completion casings are analyzed, and an actual completion casing in salt cavern gas storage is simulated as example. The example shows the randomicity of various factors can decrease the reliability of casing, but the impacts of them are quite different. The randomicity of factor having significantly reduced casing reliability should be controlled strictly.

On the basis of adjustment plan of the whole reservoir, 272 adjustment wells are drilled in Shengli Chengdao offshore oilfield. The new production capacity is bout 2.05 million tons per year. The existing problems are pointed out according to the adaptability analysis of the oil-gas gathering and transforming networks before and after reservoir adjustment in the old areas of Shengli Chengdao offshore oilfield. On account of the exiting problems of pressure drop simulation in pipe networks, the EF model is selected which can be used to simulate the pipe networks pressure drop of the old areas of Chengdao oilfield. In the meantime, the influence of pipe service life on flow efficiency and the effect of oil viscosity on pipeline pressure drop and transportation amount are studied. The design proposal of gathering transportation system on platform is identified based on the optimization of Chengdao oilfield development plan from 2008 to 2009. The isobaricchart and isothermalchart of oil-gas gathering and transforming pipeline network of Chengdao oilfield are obtained based on the simulation of existing pipeline network. Whereafter, the commissioning time and connection location of new wells will be determined. According to plan optimization, the location of No 3 platform is determined and more than 5% investment on pipe network adjustment project can be saved.

Submarine pipeline off-design suspending is the main factor to threaten the pipeline safety. Pipeline impending mechanism and dynamic characteristics of the shallow sea are carried on for safety technology of submarine pipeline impending segment in Chengdao oilfield. The allowable length of the impending pipeline is proposed, and the control countermeasures of impending segment prevention are studied. The new technologies are developed to process pipeline impending segments in domestic, which includes DZM180 high-power hydraulic hammer, underwater hammer centralizer device and submarine pipeline fixed device with adjusting rotate and up and down. The main achievements can provide the reference to the similar projects.

The crossing project of Waidiao island-Cezi island subsea pipeline is the key section of Aoshan-Zhenhai imported crude oil pipeline of China Petroleum & Chemical Corporation. This crossing section is 2350 meters in overall length with complex geologic condition and is difficult for construction. Depending on the project of "Technology Research on Directional Drilling Crossing Project of Complex and Ultra-long Stratum", the optimized crossing route of large diameter pipeline in complex and ultra-long stratum is determined by theoretical analysis and numerical simulation. The construction technology of abutment of two directional drilling machines is developed by means of studying on the key crossing construction technology of large diameter pipeline in complex and ultra-long stratum. And besides, the butting construction of guiding holes and the coordinating borehole enlarging of two drilling machines have been accomplished. The main achievements presented can provide reference to similar projects.

BHA friction calculation is always one critical problem of multilateral well in the drilling process and design. As the changes of the borehole curvature, the drilling tool friction will be increased and drilling capacity will be decreased, even because the bit can't put pressure and early damage to the drill string. Thus it is not only related to the safety of drilling, but also will increase oil production cost. In this paper, the differential equation for the frictional resistance on the drill string in branch horizontal wells was established and the total drill string friction during tripping was got.

The analytical formulas of plastic limit load of X80 steel pipe elbow with non-uniform wall thickness leading by production error have been established on the basis of the force balance method. The influences of external diameter (D₀), rate of internal and external diameter (K), and curvature radius (R) on plastic limit load of pressurized elbow are studied. The analysis results indicate that the plastic limit load is equidirectional with the increase of the rate of internal and external diameter, and curvature radius. However, the curvature radius and external diameter have little effect on the limit load. In order to validate the accuracy of the analytical formulas, 3-D finite element model of pipe elbow has been built up. The comprehensive results show that the analytic solutions are in good accordance with the numerical solutions, which can be serviced as the foundation and reference of the calculation of pipe elbow plastic limit load in field engineering.

The gas-solid flow characteristics in the annular space of gas drilling provide favorable conditions to well bore erosion by cutting particles. Collision frequency and shear stress between cuttings entrained in high velocity gas flow and well bore are high. So, sidewall rock is easily crashed, well hole enlargement is obvious. Well hole enlargement results in the variation in the stress state of BHA. The difficulty of well trajectory control is increased, thus causes the well deviation. On the other hand, cuttings cushion is formed with the results of particles detached, impacting the mechanical properties of BHA, forming buildup force, and causing hole deviation. To study the impacts of cuttings on gas drilling well deviation, using the annulus flow model and the particle collision model, distinguishing model of well hole enlargement was established. Case calculation shows that the model has high predicting accuracy, can be used to provide foundation for the optimization design and the formation rock stability analysis in gas drilling.

This paper discussed the application of reinforced thermoplastic pipes in oilfields in China. The properties, qualification tests and standard systems for flexible pipes were also reviewed. Finally, problems met during service were analyzed and some suggestions for future application of reinforced thermoplastic pipes were given.

In order to improve the injection and production rate of salt cavern gas storages, the diameter of completion casing is generally larger than that of oil well. Moreover, the loads capacity of rock salt surrounding completion casing decreases for the creep of salt, inducing the increase of external pressure subjected to the completion casing. It may lead the collapse of casing. In this paper, indoor experiments were carried out to obtain the characteristic parameters of rock salt, such as damage index, Young's modulus, etc. The numerical simulation models of completion casings were established according to the parameters. The effects of damage index, Young's modulus, creep time, and non-uniform of in-situ stress on the deformations and stresses of completion casing were studied. The studied results show the time of external pressure reaching the maximum value decreases as the increase of depth, and the deformation rate increases with depth. The maximum horizontal in-situ stress increases with time and gradually becomes stable, whereas the minimum horizontal in-situ stress decreases with time when it reaches the maximum value. The creep of rock salt increases the non-uniform of in-situ stress, which is bad for the safety of completion casing. High grade steel and large thickness casing are recommended in the completion of salt cavern gas storages.

With the rapid development and comprehensive application of digital technology, digital information technology is playing a more and more important role during the whole process of design, construction and operation management in oil and gas pipelines. In the paper, according to the characteristics of oil and gas pipelines, the functional requirements, general framework, component structure, the subsystem design scheme and security strategies related to the digital management system of oil and gas pipelines have been proposed. In addition, the selection of the related application software has also been discussed. The design scheme proposed in the paper can be used as a reference for the construction of the digital management system of oil and gas pipelines in the future.

The security, economic and steady operation of urban gas network is closely related to urban and social development. With the increasing speed of urban construction and the growing complexity of urban gas network, the gas supply duty intensifies day and day. So a modern and efficient computer automatic monitoring and dynamic analyzing system is sorely needed to satisfy the mounting demand for production scheduling and management. Considering the characteristics of the existing pipeline network in urban gas company and the near-forward phase programmer of municipal construction, making full use of the computer network and communication technology, a real-time monitoring and dynamic analyzing system of gas network characterized by universality and portability is developed in this paper. Integrating the function of data collection, monitoring, processing, statistics and dynamic analyzing of the basic state properties (pressure, temperature and flow), the system can perform the items such as critical operation point parameter prediction, main pipe long-range truncation, leaking analysis, security alarm, operation scheduling and management, meanwhile, it can also give a forecast of the consumers' gas needs, balance the demand and supply. The system provides a technological support for energy saving and safety operation of the gas company, lays the theory and practice foundation for reducing the transportation consumption and improving the transportation capacity and therefore has high application value.

To solve the key technical problems which threaten the safety of natural gas pipeline, much research was carried out. First, the finite models of pipes with different lengths were calculated and the pipeline offset tolerance criterion was established. Second, 43.335 km optical fiber was installed along the pipeline as well as the leakage inspecting box was developed. Third, the gas diffusion instant calculation method was built, as well as the fire and explosion hazard forecasting software was developed. Based on the GIS platform, the achievements in above scopes as well as the SCADA system, the GPS location service of vehicles for maintenance, the IP telephone and video service, the regional broadcasting service, and the short message service, was integrated to form the emergency rescue decision assistant system. Applications show that the system has a good ability of emergency response, command and control, and has well applied in practice.

This paper is based on the GIS platform, and combined Visual Basic with MapX software, we analyzed the leakage and breaks of the heating pipeline network. The system has achieved a two-way query management function for the network, analyzed the theoretical basis of pipeline breaks, with the knowledge of graph theory to establish a logical network model. According to the characteristics of breaks occurred in the heating pipeline network, an economic and feasible valve shutoff program is founded through comparative analysis, the pipes, users and other information influenced by breaks are analyzed and shown by the report. Finally, we proved the feasibility of the research by using heating pipeline network analysis software to verify the instance.

GPS, RS and GIS known as 3S, have been widely used in pipeline industry. GPS, Global Positioning System, has been widely used for locating pipeline characters, detecting pipeline movement, collecting geospatial data, etc. GIS, Geographic Information System, is known for managing pipeline geospatial data, environmental analysis, HCA analysis, hazard analysis, and integrity data visualization. RS, Remote Sensing, is known for monitoring geologic hazards threatening pipeline safety, monitoring pipeline leakage, evaluating environmental impact. PetroChina Pipeline Company establishes an enterprise information system with 3S technologies, which has been widely used in pipeline integrity management and daily operations. This paper specifically addresses the method of integrating GPS, GIS and RS, how 3S technologies in-depth apply in pipeline industry, and how to upgrade pipeline operator's management level.

This paper describes the geographic information system (GIS) concepts, basic principles and the status of research and application at home and abroad. And then proposed the specific functions of GIS application in the gas pipeline: the search query, data processing, spatial analysis, cartographic output, business analysis, system maintenance of all kinds of underground gas pipeline. Thereby increasing the efficiency and effectiveness of the gas company, the positioning of the place of an sudden event and the occurrence of disasters in time, and to propose effective solutions to minimize the accident loss. Finally, the GIS accident analysis module was introduced and applied in gas network leakage analysis. That provides basis for the gas consequences and reduces the accident loss.

Sewerage pipeline network is one of the city's critical infrastructures for draining water-logged and water environment prevention. Maintenance is a basic safeguard to make the sewerage pipeline network go in normal operation. As to the existent problems of sewerage pipeline network maintenance, this paper proposed the sewerage pipeline network maintenance information platform based GIS composed by maintenance application terminals, information networks and monitoring center. This paper analyzed the business model and system model of sewerage pipeline network maintenance information platform, designed the architecture, and introduced the platform application in the business process of sewerage pipeline network maintenance such as plan making, assessment, dispatching, and analysis. The platform builds a cartographic visualization environment for sewerage pipeline network maintenance, can improve the level of management and raise working efficiency.

The risk management and emergency response is among the most important safety management work for oil pipelines. As an alternative, the research on the risk management and emergency response based on WebGIS is being considered to improve safety management. An information management system for oil pipeline based on WebGIS has been established using ArcGIS. According to the collected practical pipeline data and an analytic hierarchy process (AHP), the latent risk of oil pipeline was quantified based on the modified W. Kent Muhlbauer method, the risk grading of oil pipeline was devised and daily maintenance was emphasized. The orientation system of leakage in the oil pipeline was devised based on negative pressure, and the best emergency rescue paths was decided based on improved Dijkstra arithmetic. Finally, it was demonstrated with examples that this system of the risk management and emergency response based on WebGIS is more veracious and easier to apply.

Crude oil is often transported by crude trunk line laid underground from reservoir to refineries with the help of pump stations scattered along hundreds of miles of pipeline route. It is very important to insure the safety of pipeline and protect environment around it. The whole pipeline and main equipment in stations need be supervised automatically and all operation parameters such as pressure, flow rate and temperature of oil should be recorded in real time. By use those information, leak diagnosis, combustible gas detection, surge control, cathodic protection, fire prevention and emergency shut down of the pipeline can be carried out automatically with the help of SCADA system. Pressure and flow rate regulation and dispatch orders also can be made by SCADA system. By use the system, especially for old trunk line, the staffers and their working capacity are decreased with pipeline efficiency and reliability increasing. It is successfully used in an old trunk line from Puyang to Luoyang in Henan province, in the middle of China.

Urban underground water supply network is so anfractuous that a large amount of data requires to be processed, and that the traditional manual method or recurring to drawings can hardly meet the demands. Thus, a scientific, standardized, and automatic management system is imperative. On the study of actual status in medium-sized city, this paper presents a method to establish service pipe network management system. ArcGis, OCXs and SQL database are introduced to create or show data sets and graphical elements. The consistency of graphical elements and data sets ensures the automatic operation of control points, and realizes the automatic link with drawing software and graphics. On the purpose of providing reliable basis for emergency repair, design and construction, the designed system accomplishes the inquiry editing function of pipeline route, user information, unit worker information, valve, valve shaft and well pictures. At the same time, it can also meet the need of data updating, figure editing, database information modification. It makes the water supply network management easy, facile and exact, realizes the function of map browsing, zooming in, zooming out, roaming and adding annotation, also increases the applicability of the management system.

If natural gas pipeline accident happens, it would cause serious damage and great financial losses. The application of pipeline emergency management system would shorten the processing time of accident effectively and reduce great losses. In this paper, it introduced the principle of emergency management system development, the overall structure and main function of pipeline emergency management system, and also discussed the processing algorithm of road geometry data and tiles data, which have significant reference value to the development of similar system.

The application of Unmanned Aerial Vehicle (UAV) developed rapidly since 1914 when the first military unmanned aerial vehicle was invented in Britain. It gradually turned from military utilization to civil use and recently played a critical role in disaster reduction and disaster prevention. This paper introduces some concepts and characteristics of the application of UAV in geologic hazards investigation on the basis of some practical experiences in UAV remote sensing experiments. Furthermore, the technical flow about UAV remote sensing data acquisition, processing and application is proposed. Thereby, the feasibility of the application of UAV in geologic hazards investigation for oil and gas pipelines is verified. Finally this paper points out some problems of this technique while in practical use and its development in future.

Using X-ray diffraction and thermo gravimetric analyzer to analyze the scaling samples to discuss the scaling causes. The results show that the main ingredients of scaling is CaCO₃ in water flooding. According to the scale of main component, the affecting factors of scale formation were studied by changing the experimental condition for CaCO₃ scaling. Results show that temperature is an important factor for CaCO₃ scaling. Using methods of saturation index to predict the scaling trend of Daqing oilfield, it indicates that the water flooding of oilfield has serious scaling trend, which requires promptly preventive measures. Taking "heating concentration state", "scaling ions change", "inhibition rate" as the evaluation indexes, this paper evaluates the Germany scale-buster, British net yuan scale removal instrument and Korea magnetic antiscale apparatus which are all advanced foreign physical instruments online, and searches for the suited antiscaling instruments for oilfield. Results show that the antiscaling effect of Germany scale-buster and British net yuan scale removal instrument on the water flooding are better, the inhibition rate reach 92.3 % and 91.8 % respectively.

It is meaningful to research the methods for real-time gas diffusion calculation and hazardous regions predication. Considering the effect of wind, using the revised Gaussian plume model, diffusion concentration distribution of gas was calculated fast and the comparison result showed that the accuracy of the revised Gaussian plume model was significantly better than that of the Gaussian model. Moreover, the hazardous effect of fire and explosion was analyzed. A fire and explosion hazards analysis system was developed. Using this system, the hazardous areas could be predicted, safe guarantee for rescue could be achieved and the hazards of fire and explosion could be reduced. At last, using an explosion case, the effectiveness of the evaluation models was checked in the aspect of shock wave hazard and thermal radiation hazard. The checking result showed that evaluation models for diffusion calculation and hazards predication were effective.

The damage of a post-earthquake water distribution system depends on seismic intensity. If the earthquake causes the water distribution system to leak, even though the system can continue to provide water supply for customers, the supply pressure tends to decline and the service level of the system becomes worse. Hydraulic state estimation helps utilities to assess the performance of post-earthquake water distribution systems and to make better decisions restore the water distribution systems. Based on the analysis of seismic intensity; the quantitative leakage area model is introduced to describe the failure intensity of pipes. And then, this paper combines the leakage area model and the hydraulic analysis model to establish the post-earthquake hydraulic analysis model of the water distribution systems. The leakage magnitude and the node pressure are modeled by the leakage area. The post-earthquake hydraulic model is solved using Matlab. Finally, the proposed model is demonstrated on an example water distribution system. The supply pressures at nodes with the failure of pipes are obtained resulting from the earthquake. This study builds a foundation for performance assessment and restoration of post-earthquake water distribution systems.

Rockfall is one of main load forms which result in rupture of buried gas pipeline. When the buried gas pipeline has constant pressure, the determination of the limit load of buried gas pipeline with initial crack under rockfall impact is very important for design optimization, safety operation and risk mitigation of gas pipeline. However, the prerequisite to solve this issue is to obtain the fracture parameters of buried gas pipeline with inner initial crack under the rockfall load condition and considering the interaction of buried gas pipeline and soil. In this article, the dynamic response of buried gas pipeline with inner surface semi-elliptical crack under internal pressure combined with rockfall impact load is carried out by using the finite element commercial code LS-DYNA. And then, fracture parameters of buried gas pipeline are evaluated by using the virtual crack closure technique (VCCT). Finally, the limit load for buried gas pipeline with inner crack is obtained based on tangent intersection criterion. The results and methods in this work can be referred in design and integrity assessment of gas pipeline.

Most of china natural gas pipeline passed through a variety of geological environment, the pipeline accidents happened frequently caused by landslides and collapse. The reliability of the current research on mountain pipe buried natural gas pipeline is limited to defects, almost empty, and on the judgment of the hazard is confined to the traditional reliability evaluation method. This paper uses D-S evidence theory to the mountain pipe for reliability analysis, reference fuzzy data theory, establish the model of geological disasters natural gas pipeline, and deal with the inconsistency for the same evaluation objects, make evaluation has more unity, and avoid the expertise and experience of the one-sided and subjective judgments brought results bias.

An inner support structure is usually adopted when the installed support wall is failure to satisfy the requirement of stability and control of ground movement. The influence of excavation on surrounding environment especially the underground pipelines, which is controlled by the parameters of inner structure, is a major concern for design. Numerical analyses were performed to study the pipeline deformation caused by the double-row supported excavation. Comprehensive parametric studies were carried out to investigate the influence factors for deformation control. It is concluded that the deformation of pipelines is largely influenced by the interaction between the two walls. In addition, design recommendations are given according to the tolerated stress of the pipeline.

The rockfall has threatened the safety of the pipeline when the natural gas pipelines pass through the mountainous area. The main landslide prone areas represent a threat against the pipeline system. They are identified and their landslide hazard needed to assess. In the study, the finite element model of the different sizes of rockfalls impacting buried pipeline was established in ANSYS Workbench. Based on ANSYS/LS-DYNA with the basic theory of nonlinear dynamic mechanics and dynamic calculation method, in the semi-infinite soil medium, by setting dynamic and contact parameters suitably, based on choosing suitable constitutive relation, the vibration rule of buried gas pipeline is gained by the numerical simulation analysis. The study obtains the physical process of intrusive rocks and soil and the stress of gas pipeline. Also the study gets the damage of the different rockfalls impact accident. By the way of finite element software ANSYS, the study calculates pipe stress under landslide deposits of rock by contact problem, and determines the maximum Mises Stress Criterionand failure length. The results provide the basis the data of estimating for the damaged the high pressure gas pipeline.

Seismic settlement in soft clay is often a major hazard especially in island and coastal cities, and the evaluation of settlement is very important for the design of structures and protection of structures, such as the buried pipeline. Some research has been performed on the evaluation based on data from dynamic triaxial tests or dynamic simple shear tests or resonant column tests by various researchers. However, due to its high cost and complexity, the dynamic testing is not universal at present. A new method based on Analytic Hierarchy Process (AHP) and clustering for evaluating seismic settlement in soft clay is presented in this paper. A major advantage of the proposed method over the exciting methods is that it only requires the conventional testing data rather than the dynamic testing data. A procedure to evaluate the seismic settlement is discussed in detail. Data on soft clay in Xiamen, China, were used as an example.

Rockfall is one of serious geological disasters that make effect on Lanzhou-Chengdu-Chongqing oil pipeline safety. Taking rock slope at K0526 +300 section of Lanzhou-Chengdu- Chongqing oil pipeline for example, the failure modes of rock slope are generalized through the analysis of the geological structure. According to the joint fracture density and also combining with the 5.12 earthquake collapse features, the possible block size of dangerous rock might fall in the future is judged. Based on kinematics theory, the motion state of rock falling under the different height is analyzed. RocFall software is used to analyze kinetic energy, velocity and falling path, and the location of the falling rock and its changing rule at different heights along the entire slope profile. It provides a scientific evidence for designers to determine the location of the pipeline protection and conservation measures according to kinetic energy and the falling path of rock block.

Accumulation of liquid and solid impurities will result in increase of overall pressure drop and remarkable decrease of pipeline flow efficiency during the process of multiphase pipelines. Hence, it is necessary to conduct pigging operation in multiphase pipelines so to ensure transportation efficiency. According to the two-phase flow behavior under a pigging operation, four flowing sections could be present in horizontal isothermal gas-liquid two-phase flow pipelines. Then a pigging mathematical model was built up in this paper by use of a mixed Eulerean-Lagrangean method to achieve coupling the pig movement with the fluid quasi-steady state flow. Finite difference method and Euler method were utilized to develop the model. Based on this model, a computer program was developed to numerically simulate pigging dynamics and the flow parameters such as volume flow rate of gas and liquid phases, pressure and liquid holdup were analyzed as well. The results from numerical simulation show that it is suitable to utilize the numerical simulation method developed in this paper to obtain the distribution of parameters of the pigging operation, namely, to trace the pig operation conditions inside multiphase pipelines.

The transient pressure caused by water hammer events is sufficient to fracture pipes and some equipment, and for this reason alone the study of the phenomenon in heating systems is of considerable practical importance. In addition, the by-pass pipe installed in a heating system as a protection device is effective to attenuate the transient pressure wave when power failure occurs. The paper describes the theory about transient analysis and shows technique in numerical simulation of water hammer caused by power failure taking an actual heating system as an example. The transient analysis has been performed for the heating system without and with by-pass pipe respectively firstly. Then, the by-pass pipe is selected based on the transient analysis. The objective is to show the importance of transient analysis to design and operation of heating systems and the function of transient analysis to selection of by-pass pipe.

Heavy oil has become the important substitute resource, being exploited and transported. Compared with conventional crude oil, however, heavy oil is facing serious challenges in the transportation. For the high viscosity, heavy oil is trending to adhere to pipe wall, giving rise to high flowing friction and great energy loss. Aqueous-base foam is a gas-water two-phase fluid with low flowing friction. So it may be used to break the boundary layer of heavy oil flow, and lubricate the flow passage at a certain extent. Therefore, based on gas-liquid multiphase flow theory and computational fluid dynamics technology, kinetic model of foam flow near pipe wall and central oil flow was built up. Then, flow patterns and pressure distributions of heavy oil flowing in vertical tube, inclined tube and horizontal tube under the action of aqueous-base foam were simulated. The flow properties and decay process of foam were obtained, which help us to know the influence of foam in pipe wall and heavy oil. The main factors affecting the drag-reduction were analyzed, including the flowing velocity, the ratio of foam to oil, and the diameter of pipe. Simulation analysis results may not only have some academic values for understanding the drag-reduction effect of aqueous-base foam, but also have some application prospects in energy saving and efficiency improvement of oil transportation.

The purpose of this research is to analyse influence of energy equation on gas pipeline transient simulation. The paper briefly presents current models for gas pipeline simulation, and analyses their characteristics, applicable conditions, solution methods. Then with an example, calculation errors are analysed by applying one model considering energy equation and the other neglecting to simulate a gas pipeline in service. The example results show the average relative error between the two models is lower than 1.32%, which indicates neglect of energy equation can satisfy general gas pipeline design. However, the maximum relative error is 4.40%, especially the maximum absolute error of temperature is 12.14K, which indicates energy equation could not be neglected if some pipeline simulation condition needing higher accuracy. Finally, influence of energy equation on simulation result is evaluated and some conclusions are drawn.

With the increase of water cut in oil field in China, the operation cost and fuel cost are quickly increased. In order to save energy and decrease costs, nanometer coated pipeline was used in oil field. Nanometer coated pipeline is a new type of pipeline that was internally coated by nanometer coating. Because of nanometer particle with surface effect, the surface energy of inner wall of nanometer coated pipeline is decreased. And coating has the nature of oleophobic property. So, when cut oil is transported in the pipeline, nanometer coating can reduce pressure drop and temperature. In the paper, experiment of water cut oil flowing in the pipeline was done, and frictional resistance of cut oil in the pipeline at different oil temperature and water cut are measured. Finally, the resistance of cut oil in nanometer coating pipeline compared with common steel pipeline. The study shows that the oil temperature reduces 2.5∼5°C, and pressure drop reduce about 10%.

Job training for long-distance oil/water pipeline system has many problems, like huge consumption, inefficiency and difficulty in operation. Thus a new way of training pipeline operator is proposed. The technological process of the hydraulic friction simulation is designed to help presenting the various conditions of oil/water pipeline system. With a detailed analysis of the hydraulic characteristics of four kinds of ordinary pipelines, the parameters of the control valve are calculated and finally a size of equal-percentage double-seat control valve is adopted. The calculation is very close to the result of the experiments done later, and data derived from them both prove that the control valve is suitable for any conditions, like distributaries, leakage, plug, etc. The experimental results also confirmed that real pipeline system can be simulated by two control valves and a few short-distance pipes. A simple device, composed of control valves, short-distance pipes and pumps, is enough for pipeline system job training.

Erosion damage in bend is severe due to solid particle repeated impact on the inner wall. A method of liquid-solid coupling simulation for predicting erosion in bend is investigated. Previously, on the assumption that wall thickness of model is unchanged during erosion, erosion rate, erosion site in bend was simulated based on Euler-Lagrange approach and available erosion prediction model. By solving the Euler model for fluid flow and Lagrange model for particle subsequently, move trajectory, impact force, impact angle were calculated for each particle. However, the simulation did not include the influence of reduced wall thickness on the flow field when the erosion is severe, which would affect the movement of particles entrained in the fluid in succession. As a result, dynamic meshes are used in simulation to update the computed model transiently according to the erosion deformation, which includes the interaction of structure and fluid. Compared with previous simulation, fluid-solid coupling simulation is feasible to improve the erosion prediction.

Solute mixing at the cross junction was assumed to be instantaneous and completely mixed in initial water quality models of water distribution system. With recent developments, some computational simulations and experiments verified an incomplete mixing state at cross junctions, which affected the accuracy of water quality model in water distribution networks. This paper, by the theory of computational fluid dynamics, confirms incomplete mixing at the pipe intersections. At the cross of pipe network, the forward direction of the fluid particle is directly related to water momentum. A mixing model at the cross in water supply networks is established to improve the water quality model and the simulation accuracy. For the potential of accidental or intentional contamination events, it makes a powerful prediction. This study is working to prevent and prepare for terrorist attacks, minimize public health impacts and infrastructure damage, and enhance recovery.

By using a body-fitted curvilinear coordinate system, a 3D mathematical model is developed to investigate the hydraulic characteristics of bifurcation flows in pressure pipeline, the modified k-ϵ turbulence model, finite volume method and collocated grid system are adopted. The flow parameters at the control surface are obtained by momentum interpolation method,and the SIMPLEC algorithm is used in coupling calculation of velocity and stress field. The proposed model is applied to numerically calculate the hydraulic characteristics of 60° bifurcated pressure pipeline.

According to ASME B31.8 S gas pipeline integrity management standard requirement, basic data, corrosion monitoring, inspection data, evaluation data collection and integration is to realize the integrity management foundation and prerequisite. At the same time, quantitative risk assessment is the key link of integrity management flow, with pipeline GIS and the design and construction of the database management system establishment and the consummation, efficient quantitative risk sharing of special evaluation data, the results can improve the pipeline integrity management effectiveness. Using middle database interface way, it can bring about the dynamic real-time exchange between the quantitative risk evaluation module and basic database system. According to the results of assessment, management personnel and department of pipeline can make reasonable decisions of operating measures. In improving data use efficiency, the developed management system can provide means used to ensure the pipeline in physics and function integrity condition.

Oil and gas submarine pipeline can be divided into underwater stand pipe bending, flat, expansion pipe, landing segment and land section six parts. External force, corrosion, suspended cross will cause the different failures to the submarine pipeline (Brusn Patricia, 2004 and Buell, 2006). After analyzing the submarine pipeline daily operating procedures and practice, the perfect HSE system is established based on some typical submarine pipeline environmental conditions and working conditions, which Aiming at the operation including submarine pipeline production operation, pigging operation, inner inspection main operations, combining with DF1-1 gas undersea gas transmission pipeline is applied and analysis, and put forward the reasonable management suggestions and measures, to ensure the safe operation of the submarine pipeline.

Drilling posture is an important parameter required for directional drilling trajectory control. However, owing to the particularity of directional drilling conditions, the traditional accelerometer and the gyroscope, which are big in volume, high in cost, and inadaptable to the environment, do not satisfy directional drilling measurement needs. Therefore, it is very necessary to develop a new drilling posture measurement system suitable for directional drilling conditions. Along with the development of novel sensors and microprocessors, the Strapdown Attitude Measurement System, which is based on the geomagnetic field and the gravity field and composed of accelerometers, magnetoresistive sensors and ARM microprocessors, has been used as the first choice for Carrier Attitude Measurement. Accordingly, in view of the reality in real-time measurement of directional drilling stance, the author aims to design an Attitude Measurement System adopting ARM-microprocessors. The whole measuring system consists of 3-axis accelerometers, 3-axis magnetoresistive sensors, ARM microprocessors and corresponding buffer circuits. It works on the principle that the accelerometers and the magnetoresistive sensors, while inducing signals from the earth's gravity field and the magnetic field, measure underground drill posture including the azimuth, pitch and roll. The microprocessors, after signal processing and error compensation, calculate the attitude angles. Finally, the results are outputted to PC via serial communication interfaces, so as to realize the accurate and real-time measurement of attitude angle.

Aging infrastructures, cost escalation, limited resources, stagnant productivity, environmental issues, and sprawling growth are some of the chief concerns in the management and administration of infrastructure networks, both above ground and below ground. There are strong incentives for seeking alternative and innovative means to expedite the design and delivery of infrastructure projects. Integrated Project Delivery (IPD) is a project delivery method that integrates people, systems, business structures and practices into a process that collaboratively harnesses the talents and insights of all participants to optimize project results, increase value to the owner, reduce waste, and maximize efficiency through all phases of design, fabrication, and construction. The Metropolitan Government of Nashville and Davidson County (Metro) is looking to utilize the IPD procurement strategy that would focus on providing the owner with the "Best Value". This paper describes the various procurement strategies used by MGNDC and their outcomes.

Many parts of the sewer networks in the Netherlands need replacement or repair. The development of trenchless technologies now offers a viable alternative to open trench replacement. Local governments do often not have sufficient knowledge to evaluate the different techniques and to include the influence of external effects and costs in their management strategies. A decision making model has been built that includes trenchless renovation techniques, external effects, direct and indirect costs. The model shows the advantage of of trenchless technologies over traditional open trench methods.

Glass reinforced plastic mortar pipe is a type of flexible nonmetal composite pipeline, and there are many advantages when it was used in pipe jacking engineering, such as high strength, light weight, corrosion resistance, anti-leakage, low friction coefficient, long service life. In order to determine or optimize pipe jacking construction technology, measurement orientation, resistance reduction by grouting, relay design, jacking correction and numerical simulation, it is necessary to study relevant parameters and testing technology in different size and different axial compression or different eccentric compression, including mechanical property, anti-seepage property and friction loss characteristic. Whole-Tube Test and direct shear test between glass reinforced plastic mortar pipe and typical soil had been designed, friction characteristic and grouting reduction effect between glass reinforced plastic mortar pipe and typical soil had been tested, the basic law, key technology and construction experience of glass reinforced plastic mortar pipe application in the soft soil layer had been explored. The results show that: lateral friction coefficient of glass reinforced plastic mortar pipe is relation with the typical soil, and side friction of jacking pipe is stable, the front resistance will fluctuated with the barrier characteristic; Grouting with bentonite slurry can obviously reduce the frictional resistance between the soil and jacking pipe, and routing reduction effect is related with the type of soil and pipe material.

The temperature field characteristics of ground surface of buried leakage pipeline with multi-spot leakage and the mutual influences of leakage spots provided the important theoretical basics for repairing the leakage pipeline, which can accurately determine the number and locations of the leakage spots. With buried oil pipeline as research objects, the coupled model about flow and heat transfer for oil-water two phase fluid of buried oil pipeline in the porous soil was established, and the calculated region of leakage pipeline was zoomed by similarity theory. Using the CFD software Fluent 6.3, numerical simulation of ground surface temperature field of buried oil pipeline with multi-spot leakage and the mutual influences of leakage spots were accomplished. Results show that: (1) when C_τ = C_L², N_uA = N_uB and R_eA = R_eB, the phenomenon A and B have the similarity of heat transfer and flow; (2) when the distance of leakage spots is 3m, the mutual influences of leakage spots are larger, and the leakage region of the ground surface temperature field is oval; (3) the ground surface temperature field distribution of multi-spot leakage is obvious, and the temperature difference has arrived 10K in 3 hours.

Pipeline leak detection in petroleum, petrochemical and natural gas fields is one of the important issues to be resolved. Researching of pipe leakage detection theory and detection methods which have important theoretical significance and application value, achieves the precise positioning pipeline leak, maintain the safe operation of pipelines and avoid wastage of resources. In this paper, under laboratory conditions, using of acoustic emission instrumentation combined with modern signal processing technology, and under the burst-type signals and continuous signals of different characteristics to study the characteristics of the formation mechanism of pipeline leakage signal, waveform and spectrum. Using the characteristics of leak signals to qualitative judge whether occurring leakage. By the leak detection experiments of acoustic emission on the inflatable pipeline, to research the regular pattern of leakage energy and spectrum of acoustic emission signal with the change of pressure, leakage flow rate, and transmission distance, to research the regular pattern of attenuation of acoustic emission signals with flange couplings, to research the surface roughness of leak hole on the impact of acoustic emission signals leakage. From the perspective of de-noising, using wavelet analysis of signal processing, selecting wavelet decomposition and extraction leakage signal series, so as to achieve a good filtering and signal extraction. Using cross-correlation method to analyze the signals decomposed, so as to improve the positioning accuracy.

The traditional leakage detection technologies of crude oil pipeline are introduced in the paper. These technologies include flow-rate difference analysis, acoustic wave analysis and dynamic simulation analysis. At present the assessment of leakage detection technology of crude oil pipeline is qualitative and subjective. In the paper the fuzzy assessment of leakage detection technology on crude oil pipelines is presented, it is quantitative and provides some scientific basis for the selection of the leakage detection technology for crude oil pipeline.

At present, pipeline leakage detecting technology mostly focuses on long-distance oil and gas pipeline, but does a little on the complicated pipeline system, for example ship pipeline system. The leakage detecting negative pressure wave method may easily fail to report or even misreport, because the original signal has lots of noises and the frequent adjustable pump or the reset valve of ship pipeline will produce negative pressure wave. In order to monitor the leakage of the ship pipeline, the singularity of negative pressure wave signal was analyzed through wavelet transform modulus maxima to extract the pipe working condition feature vectors effectively. From data sampling in terms of the pipe working conditions, the learning samples are obtained. Accordingly, the nonlinear mapping between adaptive neural network inputs and outputs is well established via training. Afterwards, the pipeline system leakage is detected based on input feature vectors. According to the analysis and verification from the experimental data, this method will effectively reduce the missing alarm rate and false alarm rate.

Pipeline leakage occurs frequently due to inevitable aging, pipeline erosion, abrasion and sabotage. Study on the technology of leakage detection and its location has become an emerging topic. The technology of leakage detection and its location for oil pipelines based on infrasonic wave is that detecting and locating leakage by inspecting the infrasonic wave which generated by the leakage fluids turbulent jetting on the wall of pipeline. Analysis to the low frequency acoustic signal which generated by leakage indicates that the features of leaking signals in frequency domain manifests within 10Hz. precisely, it shows spectral power changes took place in 0.4 Hz and 2 other characteristic frequency point. Therefore, we choose three infrasonic wave frequencies as test characteristic, it is 0.4Hz, 3.8 Hz and 7.2Hz respectively. It will send abnormal data and GPS time to center monitor machine. When find out mutations of 2 power spectrum of characteristic frequency, and its energy order ratio changes immediately, the center monitor machine calculates start-time and data length of capture anomalous signals from the other end stations, and then calls the data from the end stations. According to the GPS time from the stations which have generated the abnormal data, the monitored length of pipeline and propagation speed of leak signal then joint the two ends data based neural network model for further leakage diagnoses. Meanwhile, the leakage points can be located according to the GPS time lag of anomalous signals from the two stations and the velocity of infrasonic wave.

Magnetic Flux Leakage (MFL) testing method has long been used to detect corrosion defect of Oil and Gas pipelines, however, the traditional Axial MFL(AMFL) testing method cannot detect the narrow axial corrosion defect. Applying Circumferential MFL(CMFL) can make up for the deficiency of AMFL. CMFL testing method and its signal analysis is in the initial step in China. Based on ANSYS software, the CMFL model is built to simulate magnetic field. The CMFL signal from simulation model is analyzed with dimensional parameters of corrosion defect, and Radial Basis Function (RBF) neural network method is proposed to quantitatively analyze the relationship between CMFL signal and dimensional feature of corrosion defect, and the detailed procedure of RBF method is given. The results show that MFL signal can qualitatively judge the feature of corrosion defect and RFB neural network method can quantitatively determine the dimension of corrosion defect and provide a reference for Oil and Gas pipeline safety assessment.

The primary goal of this research is to improve the accuracy of leak detection and the precision of leakage position location based on transient simulation. First, the principle of applying transient simulation to detect pipeline leakage is presented, as well as its characteristic and limitation are analysed. Second, the paper analyses the influence of leakage quantity and leakage position on gas flow parameters to determine which parameter is more appropriate to enhance the accuracy of leakage detection. Third, high-precision mathematical model and numerical solution method are adopted to improve the precision of leakage position location, and finally an example is taken to demonstrate the feasibility of this method for gas pipeline leakage detection and location.

Recently, the perforation leakage accidents of gas pipeline which caused by corrosion occur frequently, and bring great economic losses, So it is particularly important to located the leakage of the buried gas pipeline in order to take measures to reduce the potential unsafe factors, immediately ,and nip in the bud. In this article, the constraint space model of geological environment where buried gas pipeline located was firstly constructed, and implemented three-dimensional testing and real-time monitoring; then referenced to the back-calculation methods of the sources intensity theory to accurately predict or determine the leakage point and improve the pipeline operating efficiency.

Using infrasonic wave to detect and locate the leakage of pipelines, can not only detect slow leakage of pipelines with little discharge on line, but also detect high compression ratio gas pipeline leak, which overcomes some shortages of detecting methods on line such as negative pressure wave. Infrasonic wave is suitable for leakage detection of all oil gas pipelines. However, owing to the limitation of frequency domain of sensor, when collecting infrasonic wave signals generated by pipe leakage, the tip of signals detected by sensor will be scrapped. In addition, environmental noise in nature intensively disturbs infrasonic wave signals. In order to reduce the rate of false, the tip signals should be compensated and disposed. In this paper, the detected tip signals is compensated by special algorithm which could quickly separate the real leakage signals from interference signals. Then, compensated signal is processed by wavelet transformation, which makes the detected signals has excellent local characteristics in time-domain and frequency-domain and effectively overcomes the shortages of the Fourier exchanges. It has an inhibition effect on noise and precisely extracts catastrophe point of signals with different resolution at different sites in time frequency plane. The rates of misinformation and omission could be absolutely reduced by means of tip compensation and wavelet transformation above.

In Horizontal Directional Drilling (HDD), the hole diameter of clay stratum usually shrinks because of the swell or expansion of the montmorillonite, the kaolin and the illite. In order to control the swelling or expansive phenomenon which leads to the shrinkage hole during drilling in the clay stratum, a new kind of Ionic Soil Stabilizer(ISS) was used to treat the clay slurry and the expensive soils on the wall of hole. The Atterberg limits test, the shrinkage test, the free swell test, the zeta potential and the cation-exchange capacity test of the clay before and after treatment with ISS were carried out. The results show that the plastic index lowers, the shrinkage limit reduces, the free swell falls, the zeta potential and cation-exchange capacity decrease in the clay after treatment by the ISS. The mechanism is that the clay soil is treated by the ISS, which can replace the exchangeable cation of clay particle surface, change the structure of pair-electricity layers of clay particle surface, decrease the thickness of adsorbed water, reduce the cation-exchange capacity, and transfer the hydrophilic clay soil to the hydrophobic by the function of physics and chemistry so as to reduce the shrinkage hole in the clay stratum.

Waxy, high pour point and high viscosity oil is transported by the heated oil pipeline. The power and fuel cost account for large proportion in total cost. Long distance heated oil transportation pipeline contains many pump stations and heating stations. In the condition of satisfying transportation amount required, the operators can formulate many operation schemes which are composed of different hydraulic and thermodynamic parameters. Determine optimal scheme is important to improve the economic returns and social benefits. Aimed at minimum power and heating cost, this paper proposes a heated oil pipeline operation optimization model with consideration of thermodynamic constraints, hydraulic constraints, pipeline strength constraints, pump characteristic constraints, temperature and pressure constraints at outlet and inlet of pump stations and heating stations along the pipeline. The model is solved by the combination of linear approximation method and simplex method. Based on theory research, computer program is developed. Finally, the practical application shows energy saving of the optimal operation scheme obtained is significant. The method and program are of widespread usage.

For the problems of truss overhead crossing design of oil and gas transmission pipeline, based on original truss design proposal of Zhijing River and practical need of the project, critical load of bars are determined by classing structure members. Using FEM analysis program, ANSYS, stability analysis of 12 truss models under such possible limit loads as earthquake, temperature change, wind-force, weight of truss and pipe and pressure test is made. Comparing stability with strength and rigidity, safety of the trusses are analyzed. The results show that buckling danger of models is mainly at upper string bar of middle truss. The danger levels of buckling and rigidity losing effectiveness are not lower than that of strength damage.

The heavy oil, of Fengcheng Oilfield in Xinjiang, is a typical oil which is mainly composed of resin and asphaltene. Because of its high viscosity, density and poor mobility, the heavy oil has to be transferred by pipeline after mixed light oil and heated. This paper states the research on the pipeline transportation technology of heavy oil of Fengcheng Oilfield and proposes six transmission solutions. From the viewpoint of economy, safety and reliability , and by contrast, the optimal solutions of the pipeline material selection, the pipeline design pressure, operating pressure, station distance, the pipeline diameter, in-station temperature and out-station temperature are determined.

Reliability inverse analysis method of X80 pipeline parameter design is proposed. Considering the condition of normal and non-normal distribution for design variables, the inverse problem calculation theory of stochastic reliability is analyzed. Based on the first order second moment reliability theory, geometric algorithm is introduced to solve inverse problem. Convergence rate of checking point is accelerated by step length choice, and the corresponding calculation program about reliability inverse problem is developed by Matlab. Taking X80 pipeline of west-east gas project as an example, the results of reliability inverse problem for pipeline parameters are given and analyzed. Also, the example results show that the method is credible and has high precise. Therefore, the method can be applied in the X80 pipeline parameter design.

The layout optimization of oilfield water injecting pipeline network plays an important role in the economy for oilfield ground engineering construction, Layout optimization can not do without a good algorithm. In this paper, the oilfield water injecting star network as research objects, the minimum total length of pipeline as optimization objective function, the uniqueness of affiliation between wells and stations and the number of injection wells can be connected such limits as constraint conditions, the mathematical model of water injecting pipeline network is established, analysis the application of electromagnetic-like mechanism algorithm in the layout optimization of oilfield water injecting pipeline network. Through using improved electromagnetic-like mechanism algorithm to solve the optimization model, determine the relationship between injection wells and water distribution rooms, the station site of water distribution room and water injection station, thus optimal or suboptimal layout form of the water injecting pipeline network was obtained. The results show that using the electromagnetic-like mechanism algorithm to solve design example has high accuracy, that electromagnetic-like mechanism algorithm exists application feasibility in the layout optimization of oilfield water injecting pipeline network, this has some theoretical basis for oil field pipe network simulation and optimization system development.

To analysis the possible failure mode of floating pipeline, the actual working condition of the floating pipeline system is simplified, and different pipeline span's analytical model is built. Using pipeline stress formulas, we get the biggest pipeline span (the distance between two anchors) and the minimum curvature semi-diameter of the floating pipeline. The finite element model of the pipe is built with the help of ANSYS software's PIPE59. The stress on the pipeline is different at different phase-angle due to the combined forces of the waves and ocean currents. The maximum stress is get at the phase-angle of 73°through calculation. At this phase-angle, the pipeline displacement and stress can be got in different directions under different span, and through comparison get the most reasonable span. With the sea condition not above forth scales, laying pipeline on sea with this span the pipeline's safety requirements can be met and the working volume of anchoring pipeline is reduced. The section fixed methods is adopted which can improve the stability and mobility of the system.

A pipeline at an offshore oil field in China South Sea is constructed. The structural design of the offshore pipeline addresses the ability to withstand operating, testing and installation stresses in the pipe as well as the ability of the pipeline system to withstand environmental forces. On the basis of design premise, stress analysis was performed using the method and procedures included in the DnV code. For in-place stress analysis, two general types of stress determination were made: hoop stress and equivalent stress. Hoop, or circumferential stress is a common computation and its magnitude depends on the pressures acting on the pipe wall. Equivalent, or Von Mises stresses are longitudinal and the effects of pressure, temperature and bending due to the external loading were considered. The calculation for unsupported span was performed considering static and dynamic situations. The thermal, pressure, soil friction restraint and externally applied axial forces were considered when calculating the stress in expansions experienced at the ends of offshore pipeline. The structural design is performed on the basis of the above stress analysis.

Non-invasive utility location techniques are vital for maximizing the potential of trenchless technologies, especially within an urban environment. This paper proposes the approach of implementing a knowledge-based system (KBS) for predicting the geophysical properties of the soil by taking into account both the geographical and seasonal variation in soil properties. The key motivation for developing KBS as a prediction methodology is the advantage of being able to gather and integrate both analytical models as well as expert knowledge based upon existing and opportunistic data. The design and implementation of this system are presented as a case study for ground penetrating radar, which is mainly affected by the complex permittivity and electrical conductivity of the soil. Soil electromagnetic semiempirical models are implemented to obtain an estimate of the complex permittivity using geotechnical properties obtained in laboratory tests or found on a national database. Hydrology models are applied to account for variations in soil water content and the associated impact on permittivity values due to changes in precipitation patterns. Results obtained from a ground penetrating radar test site with a long-term monitoring station installed are also presented, showing agreement between measured data and KBS output, and demonstrating potential for improving the effectiveness of utility surveys.

The frame of engineering-economic characteristics of oil and gas pipelines is outlined in this paper, and some key elements are also discussed on the basis of a large amount of engineering calculation and economic analysis of virtual crude oil pipeline projects, including the economic capacity limits and the economic flow velocity limits for a given pipe diameter, the economically feasible maximum pipeline length for a given pipeline capacity, and the economically feasible minimum pipeline capacity for a given pipeline length. Take Daqing and Shengli waxy crude oil for example, the basic rule of above-mentioned engineering-economic characteristics of waxy crude oil is presented in the paper. Though the basic economic data used in our research come from China, its research results and conclusions will apply to hot oil pipeline projects in other countries all over the world.

During pipeline design, it should have sufficient flexibility to ensure pipeline to prevent the excessive stress or the additional displacement caused by thermal expansion or shrinkage, and pipe support. Curved pipeline can be set in the corresponding straight pipeline, to avoid excessive additional displacement, and excessive stress, those curved pipeline in the pipeline design is called siphon. It can greatly reduce stress and displacement due to pipeline expansion and other reasons in the pipe end thrust, and thus well protected pipe connected end devices, to prevent major accidents. Therefore, the design of siphon in the pipeline design has a very important role. To this end, the finite element analysis software ANSYS is used to analyze the displacement and stress of the siphon set in the pipeline. The siphon set in the flexible pipeline are qualitative analyzed, considering many aspects and factors, such as the scheme design of siphon, and its selection and location and radius of curvature and other things. Then, some rules and conclusions are summed up to provide theoretical guidance for the siphon during flexible pipeline design, and some references for the conceptual design of siphon are proposed.

Pipe Jacking has been paid much attention nowadays because of its wide and successful application. In Hefei city, the capital of Anhui Province, how to choose the appropriate pipe jacking machine has become a headache due to some factors involved, such as cost, construction process and environmental impacts and lack of some quantitative data in this area. Therefore, an initial selection of Pipe Jacking Machine base on the soil strata mainly in Hefei City has been undertaken, varied from the area such as plain area of Nanfei River valley, monadnock area col area to expansive soil area. As a result of comparing the application according to strata, Earth Pressure Balance Machine and Slurry Pipe Jacking Machine are chosen to help engineers install pipes in these areas, which could be as references for initial selection of Pipe Jacking Machine in Hefei City in future.

The shield tail wire brushes function to seal the shield tail, thus the ground water and synchronized grouting fluid can be avoided from pouring into the tunnel, in case of which, the whole tunnel may be destroyed. While construction of the Qiantang River tunnel, the slurry shield tail wire brushes were damaged, and the ground water and slurry poured into the tunnel. Measures were taken immediately to cut off the ground water and slurry, and then a technique was designed to repair the broken tail wire brushes. After one month's repair work, the shield restarted driving again. Till the whole tunnel was completed, no similar accidents happened. This paper represents the reasons to the invalidation of the tail wire brushes, the technique to shut off the groundwater and repair of the tail wire brushes using liquid nitrogen freezing method in the artesian aquifer under Qiantang River.

In a curved circular-pipe jacking project shallow buried, it was found after the jack-through that the elevation within the range of about 15m at longitudinal direction was 15cm lower than design elevation. Discussion and analysis were made to determine an economical and effective construction scheme to deal with the axis deviation problem, which included checking calculation of the strength and crack width of some key parts and comparison of construction difficulty and cost among different construction schemes.An actual project shows that the construction scheme presented in this paper can successfully solve the axis deviation problem and has such advantages as low cost, easy operation and so on.

Dent is one of the important factors affecting pipeline fatigue life, and it will greatly reduce the fatigue life of the pipeline in service. Meanwhile the dent displacement will be changed with the operation pressure fluctuations of the in-service pipeline, resulting in a circular bending stress, which directly affect the pipeline fatigue life. For typical I type dent in the pipeline, the finite element models are established under different circumstances. A large number of the calculation results are sorted, inducted, drawed. On this basis, the results are analyzed by univariate and multivariate. Non-linear regression analysis was utilized to fit the results by matlab, some specific expressions of the relationship between the dented pipeline displacements and the dent depth, diameter and thickness of pipeline, and the dent longitudinal length are obtained after much calculation and analog.

Traditional water distribution system models, which are referred to as demand-driven analysis (DDA) are normally analyzed under the assumption that water demands at nodes are known and always satisfied, i.e., they are equal to nodal outflows regardless of the pressure at nodes. Nodal pressures are then calculated by an iterative algorithm such as Newton-Raphson or a similar method. This formulation is valid under normal/design conditions. However, in many situations such as pipe burst or pump outage or insufficient water supply, the nodal outflows affected by low pressure will decrease. Therefore, network simulation under deficient pressure conditions using conventional DDA can cause large deviation from actual situations. The purpose of this paper is to combine several pressure-dependent demand (PDD) formulations with the EPANET Toolkit to simulate deficient-network performance more realistically. An extension of EPANET which implements repetitive modifications to nodal outflows based on PDD formulations (EPANET-MNO), is also developed. First a comparison is made between respective performances of four different pressure-dependent demand functions (PDDFs) with the defined required pressure and minimum service pressure. Then pipe bursts are simulated using emitters in conjunction with PDD analysis. The paper demonstrates that good modeling performance of EPANET-MNO has been achieved for simulating deficient-network considering pressure-dependent demand.

Third-party damage does not only depend on the own conditions of gas pipes, but also is directly affected by the external environment, the operation and management conditions. As the law of overall failure of third-party damage in Sichuan-Chongqing region is in accord with Europe, according to the related failure data provided by the Europe Gas Pipeline Incident Data Group, pipeline failure probability model of third-party damage is established by linear regression analysis, scoring system and weight determination method of risk assessment. The model is modified after synthetically considering the historical failures of pipelines, environmental and operation condition of Sichuan-Chongqing region. Failure probability of 10 pipelines is calculated by Visual Basic programming. The calculation results show that the pipe diameter, wall thickness and cover depth are the main factors to the failure probability of gas pipelines. The model can be used as quantitative index of third-party damage, the quantification of the failure probability can provide the basis for the operation, maintenance and detection of gas pipelines.

According to the practical problems encountered in horizontal directional drilling, a detailed analysis of the loads in the drilling process and fatigue mechanism has been done. Based on the above, the paper have predicted the fatigue life of the dill pipes, and proposed the measures for improving the fatigue life.

Coiled tubing (CT) and coiled tubing units (CTU) technology have been widely used in oil and gas field since World War II. Coiled tubing fatigue failure is an important limiting factor for large-scale use. In normal operations, when CT going through the reel and guide arch, it bears complex loads which lead to large plastic deformations. The micro crack in the material will be grown. So the fatigue damage occurs and cannot be ignored. In this paper, the CT failure forms are introduced, in which corrosion and mechanical damage are the most common failure modes. But the traditional life prediction methods are based on the theoretical analysis and experimental study. This paper describes the fatigue damage analysis method with finite element method (FEM). By mechanics analysis of CT, the results showed that high stress and high strain are the main factors which cause CT failure in working state. Finally, based on the mechanics analysis, the fatigue life of CT strings without defects is predicted by using Manson-Coffin formula. CT life can be prolonged by improving material strength, increasing the diameter of reel and guide arch or adopting other measures.

In order to predict the breakage trends of each pipeline in the urban water supply networks, investigators collected a great deal of information about pipeline breakage, with the theoretical analysis of pipeline breakage factors and analysis of collected data, the urban water supply pipeline breakage probability model was constructed. And the research used the analytical hierarchy process (AHP) method to analyze the pipeline breakage factors; it took the pipeline internal status and pipeline external status as the 2 first level indicators, and material, diameter, pipe age, corrosion, operating conditions, seasons changing and construction quality as the 7 second level indicators. Including pipeline's length, 8 variables were synthesized in one model. As expected, all the pipelines can be sorted according to the size of the breakage probability calculated by the model. It had reason to believe that the predictive value of pipeline breakage probability was more accurate than some other models, because such comprehensive factors were taken into it. At last, the model was applied to the data collection area — one city of East China, and the analog value of pipeline breakage probability was obtained, which provided one kind of decision support for the pipeline project, so it should achieve optimization of pipeline maintenance and transformation.

Due to the long distance oil and gas pipelines across the terrain are more complex, The pipelines, inevitably, will meet meet various geological hazard area. Under the action of geological hazards, such as pipe below the subsidence, soil loss can cause conduit impending, which could cause pipeline failure. On the analysis of long-span suspended pipeline failure mechanism of geological disasters, the ANSYS model was put forward on the basis of overall pipe stress deformation increase regional quantitative calculation method. With the different boundary conditions, a finite element bearing analysis modelwas established in the paper, which is used to calculate the actual pipeline critical suspending length, critical deflection. Therefore, analytical method and the results can be used to guide the pipeline design and safety operation management under geologic hazard conditions.

Shell-contact theory model is studied in order to analyze axial compressive strain of X70 pipeline crossing faults on the condition of coupling between pipeline and soil, and pipeline failure classification method is proposed based on axial compressive strain. According to the magnitude of pipeline axial compressive strain, four grades of A,B,C,D are divided for pipeline failure degree, and pipeline failure classification standard is determined. Using the classification method and standard, some factors influence regulation of X70 pipeline failure degree are analyzed, such as pipeline wall thickness, buried depth, cracked zone width, slip amount, intersection angle. Pipeline damage location and distribution scale are compared under the condition of the different parameters variation, and sensitivity of the influence factors is summarized. The results indicate that X70 pipeline failure degree decreases with the increase of fault fracture zone width; the pipeline failure degree is more strenuous on the different soil conditions of fault both sides.

The fractured directional drilling crossing drill pipe was investigated by means of non-destructive test, chemistry component analysis, material mechanical property testing, optical microscope and SEM inspection of fracture. The results indicated that the diameter of crossing hole was greater than out-diameter of drill pipe, while rotary drilling, drill pipe not only rotated around its own axis, but also revolved along the axis of crossing hole. Therefore, high alternating stress occurred on the outside surface of drill pipe, which was nearby the reamer. Consequently fatigue crack initiated from outside surface of drill pipe and extended to fracture.

The pipe collapses under external pressure were analyzed and 3D-simulated by means of the ANSYS FEA. The paper mainly discuses the deformation theory of the pipeline of API by utilizing the ANSYS to simulate and analyses the 3D-deformation of the pipe under the symmetrical external pressure. And factors such as geometries, pressure, and its properties, which affect the capability of the resistance to the pipeline collapse, are presented. In addition, X-Component and Y-component of displacement models provided by ANSYS FEA simulates and analyses the deformation of the pipeline collapse under the symmetrical pressure and displays the 3D-simulations of von-mises stress distribution, which also simulate the whole pipe practical mechanical collapse testing.

Pipeline integrity is one of the most important concerns in petrochemical industry. Fast, effective and trenchless online inspection technique is highly desired. Non-contact Metal Magnetic Memory (MMM) Method can satisfy our need by detecting the abnormal magnetic signals in the stress concentration zone and is a new way for long-distance oil and gas pipeline detection. In this paper, the features of MMM detection for buried pipelines were summarized, some sections of pipelines in service were detected using this method, and the detection data were analyzed with differential and wavelet signal processing for noise analysis and useful signal extraction. We also summarized the relationship between the acquired signals and different types of stress concentration zones by means of pattern recognition, and performed qualitative analysis of different defect types. Excavations for verifications were conducted in the possible defects areas located by the data analysis to ensure the overall accuracy rate satisfactory. Some kinds of defects such as metal loss or corrosion were found in such magnetism abnormal areas. The results showed that MMM technique is a reasonable and feasible option for trenchless pipeline defect inspections.

This paper describes the principle of tri-axial magnetic flux leakage (MFL) sensors technology and its application progress as an in-line inspection (ILI) technology into the 21st century for spiral weld anomaly inspection. According to the failure history and risk analysis, the key threat for northeastern crude pipeline of PetroChina is spiral weld anomalies. The anomaly signal characteristic recorded by tri-axial sensors was analyzed in detail. Research and field applications show that tri-axial MFL ILI tool not only can detect various usual metal loss defects, but also can identify unusual features, such as spiral weld anomalies and girth weld anomalies, but can not classify and size the weld anomalies. PetroChina finished the classification of the spiral weld anomalies and established a quantitative relationship model between the anomaly signal and anomaly size by a series of pull test studies and field dig verification studies. Research result further expands the applications of tri-axial MFL sensors technology.

An experiment is designed to find out the relationship between the oil well tubing defects and its magnetic signals. The samples of grade N80, 3'1/2 oil well tubing with defects of different shapes and different depths are designed. The magnetic signals of the defects on the samples are detected and recorded in this experiment. According to analyzing and processing the magnetic signal of the detections it shows that the magnetic signal (peak-to-peak) value increases with the depth increasing of defect. The relationships between the depth of the defects and the parameter feature of the magnetic signals are preliminary described in this paper. And it provides the experimental basis for the oil tubing detecting and strength condition evaluating.

Early detection of leaks and condition assessment in pipelines is essential to reduce product loss and damage to the environment. This paper examines a free swimming technology for leakage detection. Leakage detection technologies reduce Non-Revenue Water, protect facilities and reduce risk for the owner. When these technologies are free swimming they minimize disruption to normal operation and other activities. SmartBall® technology is a free swimming device which is smaller than the pipe bore allowing it to travel through the line so that it will pass near to any leaks and achieve the high sensitivity. It is propelled by the flow of the fluid in the pipeline. The technologies is designed for pipes > DN250. The SmartBall® technology was originally developed and successfully implemented for the water industry, and is now also refined for use in oil pipelines. The noise signature of leaks can be clearly distinguished from any background noise. SmartBall® has been proven capable of detecting leaks of less than 6 liters per hour. Compared to alternative methods of pipeline assessment, an internal free swimming solution offers a significant cost savings as the ball can travel long distance (>200km) and can go around multiple bends. The pipeline remains in service, eliminating the need for de-watering and service shutdown.

Nondestructive evaluation of the gas pipeline system is most commonly performed using magnetic flux leakage (MFL) techniques. The data obtained from MFL inspection of the pipes is contaminated by various sources of noise: including the pipe noise due to its material properties, lift-off variation of MFL sensor due to motion of pipe and the system noise. The noise can considerably reduce the detection ability of defect signals in MFL data. The lifting wavelet packet based on a novel threshold method is presented in this paper for minimizing the effects of various sources of noise results. The approach utilizes a novel threshold processing method coupled with preorder decomposition and the best basis postorder searching to improve the performance of the lifting wavelet packet. Compared with the performance of signal noise reduction under three kinds of threshold processing mode (TPM), the test results shows that proposed method has the characteristics of fast operational speed, high space efficiency and good de-noising effectiveness. So, it is a valid on-line processing method for MFL inspecting signal.

The principles and advantages of a new type of non-destructive testing technique—Metal Magnetic Memory (MMM) technique—is briefly introduced, and the Intense Magnetic Memory (IMM) technique under conditions of high intense remanence is put forward. As application in the field of pipeline inspection, a new intelligent pipeline inspection system based on cup-type pig is developed. This device consisting of hardware system and software system has much advantages as compact structure, excellent detection capability and achieve the integration of pipeline pigging and detection. Compared with the previous non-destructive testing technology, the biggest advantage of which is that it can accurately determinate the stress and strain concentration area (which always develop into defects) to achieve the early warning of pipeline defects, not just detection of existing defects such as corrosion, cracks and etc. The accidents risk of long-distance gas pipeline can be effectively reduced.

The long-buried oil pipelines to prevent theft detection technology is a combination of external coating of buried pipeline damage detection and location and the external metal structures embedded test tube integrated detection technology. In this paper, outer coating of buried pipeline detection and location of damaged properties and principles of detection method with the magnetic the external metal structures integrated detection and location of buried oil long oil pipeline components embedded external application of technology theft.

A gas pipeline of Southwest Oil & Gas Field Company was put into operation in 2007. During the MFL in 2010, it was found that there were 408 metal losses, among which 332 internal corrosions were found and imperfects needed to be repaired. There should not have 332 internal corrosions in this pipeline according to the analysis of the internal corroion rate, the clock distribution and one similar pipeline. By considering CO₂ corrosion, 66 manufacturing defects deeper than 28% were screened out and 28 imperfects needed to be repaired based on the correction of corrosion rate calculated by de Waard's CO₂ corrosion rate empirical formula. The numbers were greatly reduced compared with those before correction. All the internal corrosions were confirmed to be manufacturing defects after excavating and data confirmation. There were 27 defects needed to repaired which was almost the same as the correction by CO₂ corrosion rate, thus this method was proved to be valid in correcting the numbers of internal corrosion.

Non-contact magnetic tomography method (MTM) is an effective non-de inspection technology used widely in recent years, which is good at the type definition and hazard assessment of corrosion defects, mechanical damage, crack-like defects, stress corrosion cracking and stress deformation for metal oil and gas pipeline. Based on the metal magnetostrictive effect and inspection method of the pipeline magnetic field stress, the principle and technical characteristics of MTM are discussed in the paper. Combining detecting process and results of this method, technical characteristics and the application ranges are analyzed together, this will provide direct reference and basis for oil &gas pipeline Integrity inspection and safety assessment.

Non-contact Magnetic Tomography Method(MTM) carries out in semiautomatic mode the non-destructive testing of pipeline metal technical condition and its insulating coating condition in 100% volume. The danger of faulty sections is evaluated depending on the degree of stress concentration in anomaly area according to RD 102-008-2009 "Directions for diagnostics of pipeline technical condition by non-contact magneto metric method". Combining the Xinjiang oilfield, pipeline company field application, there is a detail analysis about the standard contents involving defect location, defect recognition, safe working pressure, dangerous degree, repair advice, test process, data analysis, results evaluation, and on-site check program and so on. And the MTM technical advantages and characteristics are clarified, for further promotion application provides conditions.

The progress of analytical methods was reviewed for chemical composition in nickel-base alloy pipes in recent years. The basic characteristics and application instances of existing determination methods were introduced, including atomic emission spectrometry, atomic absorption spectrometry, spectrophotometry, atomic fluorescence spectrometry, X-ray fluorescence spectrometry, infrared absorption spectroscopy and mass spectrometry. The advantages, disadvantages and applicable scopes of these methods were compared. The development trend of this field was also outlined as follows: from chemical method and single element analysis to instruments analysis and simultaneous determination of multi-elements.

The Metal Magnetic Memory (MMM) Method, as an advanced pipeline non-contact and trenchless online inspection technology, is being used increasingly. But how to determine the characteristics of pipe defects from a detected magnetic field signal is still an unsolved problem. Here, we propose a new analysis method for this problem by calculating the magnetic field distribution signal of a corrosion pit in buried metal pipe with ANSYS® software. The main steps of this method can be summarized as: solving the stress concentration for corrosion pit with ANSYS® Mechanical module firstly, then coupling the contribution of stress with magnetic permeability by a user ANSYS® APDL subroutine, and finally, calculating the magnetic field signal of the pit in earth magnetic field with ANSYS® Emag module. Five different corrosion pit positions are calculated and discussed. The results show that this method can model a corrosion pit magnetic field signal successfully. This method can be potentially used to analyze magnetic field signals of other more complex cases, such as influences of pit size and depth and combination effects of pits.

This paper presents an adaptive vehicle for in-pipe inspection tasks. This vehicle can change its configuration to adapt to the diameter variations of the pipe and have general traveling-capability in pipe elbows. The transmission mechanism of the robot adopts a symmetrical three-axis mechanism along the circumference. One axle is the following mechanism, and the other two consist of a two-axle differential mechanism. This design solves the motion interference problems. The robot also has good mobility and real-time flexibility. The variable diameter mechanism combines the advantages of both nut slider and parallelogram linkage. The key components of the robot are analyzed by the finite element methods. From the simulation results, we can study the functionality of the vehicle in an early design stage, so the physical prototype development time and cost are reduced.

In this article acoustic emission sensors were used to detect simulation of gas pipeline leak and the acoustic emission signals of a pipeline leak were obtained. Acoustic emission technology was adopted to detect pipeline leak. First wavelet packet decomposition methods were used to decompose the acoustic emission signals; then the attenuated signals were remedied effectively at different frequencies. The cross-correlation technology was used to calculate the delay-time received by the two acoustic emission sensors. This method effectively solved the difficulty that the existing acoustic emission system was difficult to detect continuous signals, such as pipeline leakage giving a larger leakage location error. The proposed method pipeline leakage location error is less than 8%.

In this paper, a method for the determination of carbon and sulfur in high nickel corrosion resistant alloy tubing by high frequency furnace combustion IR spectrometry was proposed. The optimal experimental conditions were found as follows:(1) amount of mixed flux of W and Sn: 0.6g;(2) amount of sample: 0.5g;(3) analytical time for carbon: 35s;(4) analytical time for sulfur: 60s. Tests for accuracy and precision were made with standard samples, giving results in consistency with the standard values. Values of RSD'S (n=10) of carbon and sulfur found were less than 4% and 30%, respectively. The method has been applied to analyze carbon and sulfur in high nickel corrosion resistant alloy tubing with satisfactory results.

There are five basic types of pipeline trenches based on the embedment construction. The five types have a significant impact on the contractors operations. The differences reflect significant variations in mobilization, equipment, labor, and embedment material that the contractor should consider. The five types apply to both rigid and flexible pipe. While there are five basic types, there are deviations in dimensions and materials that reflect minor differences in requirements of local practices, manufacturer's recommendations, and standards. Type 1 is the standard trench with the embedment soil compacted in layers to a specified density. Haunch support is poor and this method requires the most labor and time. Type 2 is relatively unknown and uses cohesionless soils compacted in one thick layer using water and internal vibration. This method provides excellent haunch support and requires little labor and time. Normally this system requires an initial test section. Type 3 involves dumping the embedment soil in beside the pipe. This method is the most common but provides the least support for the pipe. Dumping in the embedment takes little time and labor. Type 4 uses flowable fill as the embedment. Since this method is fast, and requires little labor, it is used in urban areas where time is important. However, the system is costly because cement is mixed into the soil. Considerable money can be saved using on-site mixing of local soils instead of using ready-mix material. This system also provides excellent haunch support. Type 5 is a combination of Type 4 and any of the other types. The flowable fill is used only in the haunch area. Type 5 provides maximum haunch support with the economy of using less costly methods for the remainder of the support for the pipe.

A new construction method for installing a river crossing pipe in Tanghe County, Henan Province, without a cofferdam, is discussed in this paper. According to the characteristics of the project, no-cofferdam was used, but a combination of hydraulic trenching, pipe butt welding, pipe pulling over the river, directional sinking, and other technologies, were successfully deployed for installing the river crossing pipe (130 m, φ 630 mm). The flotation properties of a sealed (empty) steel pipe are used to foci trenching, pipe butt welding, pipe pulling over the river, directional sinking, and other technologies, were successfully deployed for installing the river crossing pipe (130 m, φ 630 mm). The flotation properties of a sealed (empty) steel pipe are used to facilitate the process of pulling the pipe over the river surface, followed by filling the pipe with water allowing controlled, "directional" sinking. This simple construction technique requires only minimal time and investment, and results in a high quality installation.

In recent years, pipeline transportation technology has been rapidly developing in China. A large number of new gas (coal gas) pipelines, sewage and running water pipelines must pass beneath existing roads, railways or buildings. Due to the local conditions or restrictions for construction, open cut digging often cannot be used, and only trenchless methods may be employed. In order to further reduce the effect of the construction on existing railways or roads, recently developed grid jacking technology may be employed, which minimizes the impact on existing structures. This paper systematically describes the design principle, the applicable scope and the construction procedure of the grid jacking construction technology. This paper also discusses the potential impact to existing lines and facilities.

Deformation modulus and shear strength values play an important role in determining failure and evaluating slope stability of a gas pipeline, which may be effectively measured by the geological strength index (GSI) method. The insitu mechanical properties for the predominant rock types, present in the exit portions of the gas pipeline being installed from ZhongXian to Wuhan, China were obtained through field investigations and laboratory. The corresponding rock mass values for the deformation modulus and shear strength are provided in the paper using the GSI method. It is important to note that the results assume slightly weathered rock masses. The estimated values can be modified consistent with actual weathering conditions, for practical engineering applications.

Pipeline installation by means of horizontal directional drilling (HDD) is becoming a well accepted installation method globally. Large pipeline projects are ongoing, and currently steel products with diameters up to 58" are scheduled to be installed over distances up to 8500 ft. During the planning stages, an assessment will need to be made with respect to the tensile, bending and hoop stresses occurring during the pulling phase of the project. In this paper we will just focus on the installation stresses on steel pipelines. The theory and some of the conclusions can be used when considering HDPE (High Density Polyethylene) or other materials. Specific attention will be needed for the bore profile, hole diameter and jobsite setup to control and limit the installation forces and product stresses. This presentation will include an overview on the different stresses (supported by formulas) and provide tips on jobsite requirements that need to be considered during the preparation stage of a large pipeline installation. Awareness of the possibilities and limitations of large diameter steel pipe will help utility companies, engineering firms, and HDD contractors to become more successful and better prepared for future "large HDD pipeline projects".

The Middlesex Water Company (MWC) is a 113-year-old, publically traded company providing water, wastewater and related utility services to a population of nearly 400,000 in central New Jersey and Delaware. Recently, MWC completed the planning, design and construction of a new 610 mm (24-inch), 1,768 m (5,800-foot) long water main to replace an existing 610 mm (24-inch) cast iron water main more than 100 years old. The existing water main conveys water from MWC's northern distribution system near the city of Perth Amboy, across the Raritan River, and into MWC's South River Basin system in southern Middlesex County, New Jersey. Due to the age, corrosivity and unstable nature of the surrounding environment, the existing main experienced several breaks, requiring costly emergency repairs on an increasing frequency. These outages caused major operations disruptions and repairs were costly due to access impediments associated with the river, soft sediments adjacent to and under the river, and regulatory considerations associated with adjacent wetlands and river navigation. Alternative construction methods for crossing the 1,463 m (4,800-foot) wide Raritan River were evaluated. Studied options included open-cut trenching, microtunneling, pipe jacking, conventional tunneling and horizontal directional drilling (HDD). Factoring in construction schedule, cost, sustainability, impacts to the environment and marine traffic, and permitting requirements, HDD and fusible polyvinyl chloride pipe (FPVCP) were recommended for the river crossing. The final design consisted of an HDD crossing, approximately 1,635 m (5,365 feet) long, using 610 mm (24-inch) FPVCP. The completion of this HDD and pipe pullback makes this the longest FPVCP pullback for a diameter of 610 mm (24 inches) or greater completed to date in the world. This paper highlights the planning, design and construction of this 1,635 m (5,365-linear-foot), 610 mm (24-inch) FPVCP water main installed using HDD techniques across the Raritan River. Elements of this high-risk project that are discussed include the geotechnical investigation, HDD construction techniques, staging and fusing of the FPVCP, and startup. This paper also discusses the design process and compares pulling forces predicted by the design with the actual pulling forces recorded during pipe installation This project was awarded the 2010 Project of the Year for New Installation by Trenchless Technology.

The operation of a city gas pipeline sometimes, requires alterations, or possible urgent repair due to damage. In these cases, hot work construction, such as electro-welding or gas welding, which is accompanied by flames, is typically performed. In this paper, the safety factors associated with avoiding potential accidents due to fire and explosion during the hot work process, as applied to city gas pipelines, is discussed. The information provides an understanding of the causes of related accidents, allowing one to avoid such situations, as well as countermeasures for controlling and reducing the consequences.

At present, trenchless technology is universally recognized by owner and the public for its beneficial and environmental friendly character. As one of the most mature trenchless techniques, slurry balanced pipe jacking is playing an important role in municipal pipeline construction. However, it is the first time for Xiamen to install a power pipe with 2000 mm in diameter and 5 meters in embedding depth using slurry balanced pipe jacking method, which is uncommon even around China. The power pipe was successfully installed after improvement of construction equipment and technology, which can be referenced by other large diameter power pipe construction engineering.

Based on diverse situations of the flowline of subsea Christmas tree installation and its working conditions, a theoretical model for calculation of the flowline is proposed by taking comprehensive considerations of different influencing factors, such as water depth, temperature of petroleum and gasoline, and angles of the flowline. By using the ABAQUS software, a finite element model for the flowline operating in an oil field in South China Sea is developed for verification of the proposed theory. The analysis and calculation present the variation of the thermal stress with different water depth, different oil & gas temperature and different bending angle of the flowline, and provid a theoretical support for the appropriate bending angle design of the flowline in the specific fields.

Aimed at high water cut crude oil, adding new-type flow improver to oil-water mixture pipeline could obviously lower the mixture's viscosity to advance the phase transition point, and could greatly reduce the on-way resistance; meanwhile, flow improver could reduce the cold start-up pressure, and the calculation formula of the cold start-up pressure gradient was built. Using the new-type flow improver to carry out low temperature transportation, the temperature of oil gathering decreased greatly, and economic benefit was obvious.

Because of the factor of environment and safety, the marine LNG loading platform which located away from the coast is the trend of the next generation of LNG loading system. And the subsea LNG cryogenic pipelines are used to connect the marine loading platform and the onshore plant. The contraction of LNG pipeline,which caused by low temperature during operation, mayimpact the structure of pipeline, It is necessary to use compensation structure in the LNG pipeline to deal with the contraction of pipeline.. This paper use bent pipe to compensate the amount of contraction of subsea LNG cryogenic pipeline. The bent pipe will be installed in the land part of LNG pipeline in order to facilitate maintenance.To reduce the cost and prevent the non-uniform change of shape of pipeline, the bent pipe will adopt the structure of single wall line, with insulation on the outer surface of the pipeline. The stress of pipeline, especially at the ends and elbow of pipeline, will be analyzed by finite element model to ensure the stress during the lateral and longitudinal displacement of pipeline is not exceed the yield stress of pipeline. Furthermore, the shape of insulation will change with the pipeline, so it is necessary to study the paving pattern of insulation to ensure the enough insulating property during the changing of the shape of pipeline.

The crossing angle between pipeline and fault has a strong effect on pipeline strain and it is a main parameter in the design of buried cross-fault pipeline. Therefore, to ensure the earthquake resistance of buried pipelines, it is necessary to study on the best crossing angle between buried pipeline and fault. There are a lot of researches on the best crossing angle between pipeline and strike-slip fault without considering inner pipeline pressure. But the best crossing angle between pipeline and normal (reverse) fault has not been studied yet. Therefore, based on the finite element method, the influence of the crossing angle between pipeline and normal fault or reverse fault or strike-slip fault on pipeline strain was quantitatively analyzed by the considerations of the different material behaviors of pipe, inner pipeline pressure, fault dip and fault dislocation. Finally, according to the rules of controlling both the tension failure and the compression failure of pipeline, the best crossing angle of normal fault and reverse fault should be about 10 degrees. The best crossing angle of right-lateral strike-slip fault is related to fault dislocation. When the fault dislocation is small, the best crossing angle should be about 10 degrees. Otherwise, it should be about 60 degrees.

By using the ABAQUS software, a finite element model for the flowline operating in South China Sea is developed and the structural strength analysis of the flowline under different water depth is performed. Meanwhile, by using genetic algorithm, the variation trend is forecasted, which is based on the calculation results of the flowline under different water depth, and the reason why the flowline of subsea Christmas tree occur buckling under the external pressure is analyzed. Through calculation and analysis, the variable rule of the structural strength of the flowline under different water depth is summed up, and suggestions for the design of the flowline of subsea Christmas tree are provided.

Because of the relatively low critical temperature (31.1°C) of CO₂, and the effect of environmental temperature, elevation changes along the route and the frictional resistance, phase change may occur during the transportation (Hein 1986). Phase change will bring fluid in the pipeline a sharp temperature drop, produce an effect on Mechanical properties of pipeline material and cause pipeline rupture. In order to avoid phase change during the transportation, it requires precise calculation of the operating parameters along the pipeline. In this paper, BWRS equation is used to calculate the physical parameters such as compression factor, enthalpy and predict phase equilibrium. Based on hydrodynamics and thermodynamics, the impact of elevation, temperature and other factors are considered to establish technological calculation mode of CO₂ pipeline. Then the mode will be used to analyze the temperature and pressure distribution along the pipeline, to predict the phase change, and finally technically demonstrate the rationality of pipeline design and operation projects.

A large diameter steel pipe was tested under static load at the Center for Underground Infrastructure Research and Education (CUIRE) laboratory at UT Arlington. The backfill soil properties were first determined in the laboratory. 0.3 m of granular embedment was placed inside a concrete load cell. The 6 m, 1873 mm diameter steel pipe was placed above the embedment and backfilled with native clayey soils obtained from the Integrated Pipeline (IPL) project site in the North Central Texas, USA. The backfill soil was compacted and placed up to one 0.3 m above the crown of the pipe. Additional load equivalent to 3 m of native soil was added incrementally. Vertical loads at crown and bottom of the pipe and horizontal loads at the springline of the pipe were recorded as loading was increased. Changes in vertical as well as horizontal diameters of the pipe were measured during and after installation of the pipe. The purpose of the test was to study behavior of the large diameter steel pipe under native backfill and calibrate the related Finite Element Model (FEM). This paper describes details of the test and presents the preliminary results obtained. Based on the results of this and other tests and accompanied FEM, appropriate design changes for trench backfill materials using native soils will be made. It is expected that using native backfill materials would reduce project costs and environmental impacts.

Renewal of old and crumbling underground pipelines in the U.S. presents a vast opportunity to utilize new techniques and methodologies such as Trenchless Technology. TT is a fairly new approach to underground pipeline renewal and the concept is generally divided to two main categories — "Installation" and "Renewal". Cured- In- Place Pipe (CIPP) and Pipe Bursting (PB) are among the most widely recognized renewal methods and although there have been numerous papers and considerable researches in both methods, there is a need to evaluate these two methods in a comparison format with traditional open-cut technique to determine the advantages and disadvantages of each method from the perspective of differing parameters. This paper will evaluate the CIPP AWWA Class IV, PB, and open-cut methods based on cost, diameter size ability, and service re-connection to answer the simple question; which one to use for water main distribution renewal?

Till now, welding repair on large diameter natural gas pipeline is still time consuming, costly, and very risky due to heavy concentration of gas and gas condensate at weld zone. This paper will show our study on using partly freezing sealing technology with frozen wick sealant in special dumbbell shape to effectively seal pipeline in circumstances of pipeline-leak repair, pipeline realignment and similar projects alike. Our experiment statistics show that this technology can seal gas condensate and gas completely and increase the newly-developed sealant's pressure-bearing capacity to 1.5MPa, which dramatically reduces time and costs involved in gas metathesis. Moreover, the sealant can be easily discharged from pipeline after thawing. In summery, the partly freezing sealing technology with safe and simple procedures is practical and of significance to welding repair work at large diameter natural gas pipeline.

The trenchless technology has been widely used in water pipeline recovering technology, in which various kinds of pipes are used. This paper discussed the appropriate supply hydraulic calculation method for respective pipes through analysis of flow pattern in the pipes. Then their respective water supply capacities are analyzed qualitatively and quantitatively, which can provide references for designers, managers, construction workers.

Pipeline transportation has a history of more than one hundred years as one of five main transportation methods of oil and gas. With the development of oil and gas producing, the development of pipeline becomes more rapidly in recent years. Oil and gas pipe inevitably suffers damages such as perforation leaks, reduction of intensity and so on due to corrosion, mechanical damage, weld defects, third-party damage and other factors during operation. Those damages lead to serious economic loss and great security risks to lives and environments. Pipeline rehabilitation technology can solve this problem; it can efficiently, economically and quickly restore the safe operation of pipeline. Therefore, the pipeline rehabilitation technology in pipeline project plays an important role. This paper describes the excavation and trenchless rehabilitation technology that commonly used for onshore pipeline, and introduces overwater and underwater pipeline rehabilitation technology for subsea pipeline, and makes the prospects of pipeline rehabilitation technologies.

In-field repair of a damaged pipeline and crack arrester on a high pressure pipeline must be performed safely, efficiently, rapidly and reliably. Recent developments in high property para-aramid fiber and carbon fiber reinforced composite repair and local reinforcement have led to their increased usage across aviation and space engineering. The disadvantage of epoxy used as the matrix of the fibers is that the interfacial bond between fiber and matrix is poor. In the research, SiO₂ nanoparticles were used to modify the matrix, and when the content nm-SiO₂ is 0%, 3% and 6% (mass fraction), the curing reaction kinetics were analyzed by Ozawa and Kissinger methods respectively through Differential Scanning Calorimetry (DSC) tests at various heating rate of 10°C, 15°C and 20°C; Dynamic mechanical properties were analyzed through Dynamic Mechanical Analysis (DMA) tests. The result shows: 1) Characteristic temperature of curing reaction has a close relation with heating rate. The curing reaction peaks of the system move towards high temperature region with the increase of heating rate, and the temperatures at peak initiation and peak finish have similar phenomenon. 2) The reaction order is 0.87 in nm-SiO₂/epoxy system, which is similar to that in unmodified epoxy system. The curing reaction of all the systems are complex reaction process. The activation energy in nm-SiO₂/epoxy system is a little decreased by about 3%. 3) The addition of nm-SiO₂ infused in epoxies can make the storage modulus of composite increased, especially the storage modulus of nanocomposite containing 3wt% nm-SiO₂ improved obviously. The addition of nm- SiO₂ in epoxy can make rigidity and resistance to deformation of material improved.

Aramid fiber/epoxy composite can be used for repair of damage pipelines, local reinforcement of pipelines, structure layers of pipelines in oil and gas field. F-12 aramid fiber and Domestic aramid fiber III (DAF III) are two kind of high property para-aramid fibers. In the research, 3% (mass fraction) SiO₂ nanoparticles was used to modify the matrix. Tensile strength, flexible strength and compressive strength of the matrix were analyzed, and the fracture surface was analyzed by SEM. Adaptability between both the fibers and epoxy was evaluated through tensile strength test of strands impregnated with epoxy. Photos of strands impregnated with epoxy was used to analyze the surface macrostate of fibers, and SEM was used to analyzed surface microstate and fracture state of fibers. The test results showed: 1) Epoxy modified by nm-SiO₂ is an efficient way of increasing mechanical properties of matrix. The tensile strength and the flexural strength of the epoxy-SiO₂ matrix are higher by about 7.6% and 2.6% respectively than that of unmodified epoxy. The compressive strength of the epoxy-SiO₂ matrix is much higher than that of unmodified epoxy matrix, significantly improved by about 160.8%. SEM micrographs taken on the fracture surface also approved that epoxy modified by nm-SiO₂ is propitious to changing the fracture mode of material. 2) The impregnated surface microstate of F-12/nm-SiO₂-epoxy and DAF IE/ nm-SiO₂-epoxy are both better than that of the matrix unmodified composite. The tensile strength and elongation at break of F-12/nm-SiO₂-epoxy is higher than that of F-12/epoxy by about 10.1% and 7.6% respectively. The tensile strength and elongation at break of DAF III/nm-SiO₂Vepoxy is higher than that of DAF III/epoxy by about 31.1% and 33.3% respectively. 3)The fracture modes of F-12/epoxy and DAFIII/ epoxy composite have been changed and the properties of materials can be improved through the addition of nm-SiO₂ in the matrix.

As the needs for solving water quality deterioration in water supply network increased, more attention has been paid to effective pipeline cleaning technologies. Amongst them, water-hammer method and barometric-pulse method have the potential of scouring and removing the "growth-ring," which is the main reason for the secondary pollution as well as the cutback of flow capacity in pipelines. In this study, in order to discover the optimal conditions of water-hammer method and barometric-pulse method, a test platform has been designed and set up. Moreover, a comparative study on the effectiveness of two methods has been conducted. The results indicate that barometric-pulse method shows a better cleaning effect due to its superior characteristics of flow turbulence.

As part of the U.S. Environmental Protection Agency (EPA)'s Aging Water Infrastructure Research Program, one key area of research pursued, in collaboration with wastewater and water utilities, was a study of the current approaches available for making rehabilitation versus replacement decisions. The purpose of this study was to: (1) identify the current methodologies and decision support models being used for determining how to rehabilitate or replace underground utilities; (2) identify the critical gaps of these current models through comparison with case history data collected from utilities; and (3) assess the feasibility of substantially improving upon existing approaches. This paper identifies the decision support models and methodologies that have been proposed/used in the US for method selection and discusses the improvements that are required in existing models to make them more directly useful in decision support. A summary from case study visits to utilities in terms of how cities actually make these decisions is also provided. Proposed improvements for the next steps needed to improve current method selection support software are also discussed.

Cured-In-Place-Pipe (CIPP) method has nearly forty years of history in the area of sanitary sewer and storm drain rehabilitation. CIPP is now known as one of the most grown trenchless technologies and has been utilized by many utility owners throughout the globe. However, CIPP technology still has an opportunity to improve its technological challenge recognized from various field environments and experiences. Development of an automated air pressure inversion system using vertical roller brackets (ABL system) is initiated to improve the conventional CIPP inversion process. The ABL system uses an advanced air pressurizing method and lining feed process using a number of vertical roller brackets. The greatest benefit of the ABL system is an enhancement of controllability during CIPP inversion process. An inversed lining can be pulled back and re-inversed especially when it negotiates a sharp radius turn or large offset. Other benefits include extension of installation length, minimization of air loss, and maximization of productivity. This paper presents the ABL system and describes CIPP liner installation by using a new technology.

Relining started almost 40 years ago with the first installations in London by Eric Wood. It provided a completely new way for the rehabilitation of damaged sewers. Since then different liner families were developed; they are based on different resins, fibers and curing technologies. The most common matrix resins are unsaturated polyester resins (UP-resins), vinylester resins (VE-resins) and epoxy resins (EP-resins). With respect to the type of fiber and textile fabric needle felt liners and glassfiber reinforced liners (GRP liners) are discriminated. Modern GRP liners are produced from acid resistant glass fibers (ECR glass or Advantex®); the use of standard E-glass is strongly decreasing. In case of thermal curing the liners may be cured by warm water or by steam. Alternatively, UV-light is employed. These so called UV-liners form the strongest growing product family in the market. As a consequence, a manifold of liner products is commercially available form roughly 10 European manufacturers. For each rehabilitation project the civil engineer may choose the most suitable and cost efficient liner and curing method. Often one of the most important arguments in the decision process is the required time to do the job on the site: Public life and traffic should be disturbed as little and as short as possible. In factories, refineries and chemical plants or on air ports the whole rehabi- litation job must fit into the short periods for maintainance, periodical shut down or night flight break.

The influence of foundation pit excavation on underground pipelines nearby is an important subject, as complicated construction is occurring at an increasingly rate in cities in recent years. In order to address this potential problem, a numerical calculation method has been adopted to study a typical installation containing four representative pipelines to determine the effect of the proximity of the foundation pit on the displacements and forces imposed on underground pipelines. The following conclusions apply: (1)The resulting displacement of the underground pipelines increases with the excavation depth of the foundation pit, and at an increasing rate. (2)The influence of the foundation pit excavation on the earth pressure imposed on the pipelines is rather complicated. (3)It is therefore difficult to ensure the safety of underground pipelines by means of an underground diaphragm wall only, and other support or protective measures should be considered.

By combining the two methods of AHP (Analytic Hierarchy Process) and Fuzzy (Fuzzy Comprehensive Evaluation Method), this paper processed the evaluation of geological hazard susceptibility of zhongwu pipeline. First of all, according to the geographic background and running situation of zhongwu pipeline, the area which zhongwu pipeline pass is divided into 72 regions. Secondly, establishes hierarchical structure model and judgment matrix, and calculates the weight of geological hazard probability Index by AHP. Thirdly, calculate the membership degree based on fuzzy comprehensive evaluation method, and achieve geological hazard susceptibility partition of Zhongwu pipeline. The result indicates that the method is reasonable and effective. At the same time, the evaluation result has upper precision and greater fitting degree than 90 percent. Finally, combining Medium-Range or Long-term Weather Forecast and the information of pipeline achieve Long-term geological hazard warning is discussed.

It is important but difficult to estimate the effect of tunneling on adjacent buried pipelines during the construction of urban metro network. In this research, three-dimensional numerical analysis has been carried out. The method to normalize the maximum bending moment of the pipeline is discussed first. Then the effect of a number of factors, including the pipeline stiffness and depth, volume loss, soil stiffness and tunnel depth, are analyzed. Based on the results, a simplified method to calculate pipeline maximum bending moment is proposed for preliminary pipeline design.

Aiming at the actual engineering problem of influence of foundation pit excavation on underground pipelines nearby, basing on elastic foundation beam theory, the calculation method based on field test ground settlement curve of calculating the influence of foundation pit excavation on underground pipeline nearby is proposed. This method makes up the shortage of supposing the ground settlement curve above underground pipeline to be parabola, which makes the calculation result more accurate. Finally, the solution process of this method is illustrated through an engineering example. The vertical displacement equation of underground pipeline is obtained, and its value solution is solved with Matlab software, which is in good agreement with that of field test.

Based on ArcGIS, a risk management system of city lifelines was built. For the system, the database of the city lifelines information and layers are designed based on the architecture of intelligent decision system. Using improving the object of Kent method which is commonly used in international, and some simulation model of the consequences of major accidents, the risk management model database was built. Then a risk management system of city lifelines was built, which took database, methods database, models database, and knowledge database as the core. The system is a visible management means to provide supervision advices for risk management of city lifelines.

With the rapid construction of China's long-distance natural gas pipelines, it is inevitable that in many regions the high pressure pipes are laid parallel and work at the same time. Once one of the pipelines explodes caused by the defects on the pipe body, the third-party damage, or the geological disaster etc., the blast shock wave and the combustion radiant heat may lead to a chain failure reaction to the parallel pipe. This paper focuses on the explosion impact loading, an interaction mode among explosion loading, soil and gas transmission pipeline is established. In order to find out the main factors which influence the security conditions of parallel laying pipelines, the relationships between pipe's laying space, wall thickness and internal pressure under blast loading are obtained by using LS-DYNA finite element software, accordingly, the limit state of the parallel laying pipelines would be determined. The study will give the theory adding of the parallel laying design of long-distance gas transmission pipelines, and the results have certain reference value to the study and formulation of protection measures.

Long-distance buried pipelines are subject to various and complicated geological conditions. The finite element analysis method is used to study the influence of site conditions on the response of buried pipelines to seismic conditions. The buried pipeline is modeled as a shell element, subjected to simulated seismic waves. The seismic performance of buried pipelines in different site conditions is compared, and the influence of the main technical parameters is evaluated. The results indicate that the thickness of overlaying soil layers and the shear wave velocity significantly affects the seismic response of long oil transportation pipelines.

With the global escalation of terrorist attacks, water supply network has become the weak links exposed to terrorists. Many countries have already raised infrastructure security as homeland security strategies, developing a corresponding tool to simulation and analysis vulnerability for the water distribution system (WDS). This paper is aiming at the non-source pollution in the WDS, and the water quality monitoring points are established. According to the theory of tracing exogenous pollutants in water distribution network, the model is developed by TEVA-SPOT optimizing monitoring point placement of water quality. This study is working to reduce system vulnerabilities, prevent and prepare for terrorist attacks, minimize public health impacts and infrastructure damage, and enhance recovery.

Aiming at the practical engineering problem that the construction of jacked piles will do great harms to the adjacent underground pipeline, a rational three-dimensional finite element model was established. Using the displacement penetration method, the complete uninterrupted penetrating process of single jacked pile was simulated based on ABAQUS. The elastoplastic constitution law, large deformation, soil's gravity field, pile-soil friction and pipeline-soil friction contact were taken into account. The compacting effects on underground pipeline by construction of single jacked pile was simulated and analyzed. The influence range, the maximum value of the stress and displacement and the distortion law of the pipeline induced by jacked pile were obtained. The results showed that the horizontal displacement was much bigger than the vertical displacement, and the pipeline would fall at the end close to the symmetric plane and lift at the other end. The principle tensile stress mainly aroused by the pipeline's horizontal displacement would cause tension fracture. The sections of the pipeline near the pile were dangerous, which should be particularly protected. The stress and displacement would increase with the increment of pipeline's embedment or the decrement of the distance between pile and pipeline, and the later's influence was more greater than the former's.

A method for monitoring deep displacement of pipeline landslide based on Fiber Bragg Grating strain (FBG) tube is proposed in this paper to solve the problem of landslide that threatens pipeline safety. Based on the characteristics of fiber Bragg grating such as compact volume, corrosion prevention, electromagnetic interference resistance, good stability and easy wave division multiplex, a FBG strain tube is designed. Such FBG strain tube has a guide channel inside, which made declinometer applicable. 4 sets of FBG strain tubes that installed in 110 mm boreholes extending 5 m beneath bedrock have been successfully applied to a pipeline landslide of large scale in Sichuan Province. In addition, a sensing network was established and an automatic real time monitoring system which successfully monitored the impact of Wenchuan Earthquake on pipeline landslide was formed. According to comparison of gained data with that measured by declinometer, this monitoring method is demonstrated to be feasible.

Under the driving of pressure pump, hot water in pipe can be regarded as pulsating fluid. The whole structure, pipe-fluid-support system, can be viewed as pulsating one which is acted on parametric excitation. According to Hamilton principle, the partial differential FSI equations of pinned-pinned supporting pipe was set up and its variables were discreted by Glerkin method, then the ordinary differential equations were solved by Multi-scale method. At last, some new laws and conclusions were obtained and which are helpful to engineering.

The plan repair or rush-to-repair of a hot oil pipeline may make it shut down. As the pipeline is shut down, the oil's temperature will decrease continuously and the heavy organic molecules will crystallize or aggregate and suspend from the oil, which can strengthen their interaction and worsen the oil's flowability, even form a network structure or freeze the pipeline. Once the pipeline is frozen during its shutdown, it is likely to trench the pipeline to unblock and restart the pipeline. Hence, it is necessary to focus on the experimental study of the shutdown and restart behavior of a hot oil pipeline to provide a safe and effective restart proposal for the shutdown pipeline. Considering the potential frozen risk of the shutdown pipeline, this paper takes BZ28-2S crude oil and the mixture of BZ19-4 oil and produced water as the study objects, and the change laws of restart pressure of the shutdown pipeline as the shutdown time and temperature for different study fluids were simulated by using a loop system, and the main factors affecting the restart pressure of the shutdown loop with studied fluids were analyzed, and the relationship between the pressurizing speed and the restart pressure of the shutdown pipeline were investigated, and then an effective method to ensure the safe restart of a shutdown hot oil pipeline was presented. The results indicates that the longer of shutdown time and the lower of shutdown temperature, the higher of the restart pressure; and the restart pressure also increases as the restart speed due to a higher instant pressure, accordingly the restart time becomes shorter. The low-temperature flowability of BZ28-2S oil and BZ34-1N oil are poor, thus the restart pressure should be higher during the pipeline's restart; the yield value of BZ28-2S blended oil is high at low temperatures, hence the temperature drop during shutdown shouldn't be below 25°C. Under the same shutdown temperature and time, the restart pressure of the BZ19-4 oil-water flow decreases while its water cut is higher than that of the phase inversion point and the pumping behavior of the restarted oil-water flow worsens.

With FLAC3D finite difference analysis software, the effects of the existing buried pipeline on the stratum settlement due to shield tunneling construction in the condition of that the pipeline is parallel to the tunnel are analyzed in two aspects of the transverse and longitudinal settlement feature. Results show that the existing buried pipeline has remarkable influences on the displacement field of the stratum around the tunnel. On the ground surface above the existing buried pipeline, the transverse and longitudinal settlement curves of the stratum are all obviously less than those without considering the buried pipelines. The stratum displacement field is more severely affected when the stratum is closer to the existing pipeline. Furthermore, the existence of the buried pipeline evidently obstructs the propagation of the stratum transverse displacement wave and shields the development of stratum subsidence above the pipe.

In this paper, the status of the natural gas pipeline network of Beijing is analyzed and the concept of "hidden danger" in urban public facilities is proposed. Various types of such hidden dangers which may cause gas accidents are classified by the theory of Human-Machine-Environment, as well as by the different management levels of similar hazards in cities, counties and enterprises. Moreover, the hidden dangers in natural gas pipeline network of Beijing are analyzed under the "Iceberg" theory, which is a fundamental theory of risk, addressing prediction and containment. A system for managing hidden dangers is therefore established, including supervision and rectification. The system has been used, to analyze the hidden dangers in the city of on a statistical basis, providing a scientific basis for decision making by relevant management or authorities.

In recent years, "digital pipeline" technology has been applied to an increasing number of applications, and has promoted the further development of pipeline integrity management. This article presents the overall framework of the digital pipeline system, comprising the pipeline integrity management system that includes risk assessment, evaluation of corrosion and associated protection systems. As an example, the technology has been applied to a domestic oil pipeline to obtain a comprehensive pipeline integrity assessment. The results of the evaluation fully reflect the pipeline status, risk factors and potential causes of accidents, and provide the basic information required for pipeline integrity management.

MoDa pipeline is constructed from Mohe to Daqing since 2009, with 933 km length and 32 inch diameter. This Pipeline is operated by Petrochina Pipeline Company. It is the first completely buried oil pipeline constructed within the continuous and discontinuous permafrost zone of China where the average temperature in winter is about –30°C. This pipeline will transport roughly 300 thousands barrels of crude oil per day to northern markets of China from January 1²¹, 2011. It's a significant cooperation for both Russia and China. This paper will review the design, construction, and operational challenges of this pipeline. Analyses the happen possibility of frost heave/thaw settlement and slope instabilities in specific areas. Although traditional methods already were careful coincided, such as minimize thermal disturbance to the soil during construction, insulating permafrost slopes to minimize post-construction thaw, accommodating ground movement, and evaluating the effects of moving water bodies adjacent to the pipeline right-of-way, monitoring technology is still significant methods which include using thermostats sensors to monitor soil temperatures, using Brag fiber sensors to monitor material strain, using special displacement instrument to monitor frost heave and thaw settlement, Of course, the use of in-line inspection tools will be valuable as a supplement to conventional geotechnical monitoring. According to these monitoring technical and data been selected, The relationship between pipe and soil have been made out for specific sites in order to assess the potential for frost heave thaw settlement and slope movement, and also include if this generated strains in the buried pipeline exceed the strain capacity. All these consequence will be significant for the integrity management of this pipeline. In the end of this paper, several suggestions will be given to guidance next management work.

Natural gas pipeline is very important to national economy. Unfortunately, leakage of natural gas pipeline often occurs with many reasons such as corrosion, third-party interference and so on, which may lead to damage to property and life. Thus, the size of the diffusion region of the leakage is very important to rush repair, which can predict dangerous area after leakage. This paper uses the software FLUENT to simulate the diffusion rule of natural gas pipeline leakage after ruptured, and analyzes the influence of different wind velocity, leakage rate and the spread of the terrain . The analysis shows that all factors will increase the danger of gas leaks after diffusion, in which the leakage rate and wind velocity are larger.

Several thousands of kilometres of pipes and cables are buried beneath our streets. As they are not visible and easily accessible, the monitoring of their integrity and quality of their contents is a challenge. Any information on these properties aids the utility owners to plan and manage their maintenance regime. Traditionally, expensive and very localised sensors have been used to provide irregular measurements of these properties. In order to have a complete picture of the utility network, cheaper sensors need to be investigated, which would allow large numbers of small sensors to be incorporated into (or near to) the pipe leading to so-called smart pipes. Assuming the lifetime of the sensors is of the same order as the buried asset itself, it will not be possible to power these sensors using traditional power sources. This paper focuses on the different options available to power the sensors (non-regenerative and generative) and introduces ideas for the communication between these sensors and power management systems.

This paper emphasizes on the choice of economic heating regulation method to obtain the best adjusting method, through various regulating calculation analysis. Therefore, a simple central heating system model is established. By using the model, the calculation of hydraulic power, flow, pressure loss and head of each section, as well as the selection of appropriate circulating pumps for different adjusting methods, are implemented. On the basis of hydraulic calculation, mathematic models of quality regulation, quality-flow regulation and grading variable flow quality regulation are listed. Through calculation of the model by using 3 heating adjusting methods, supply and return water temperature and temperature adjustment curve are concluded. Finally, through economic analysis, the most appropriate optimization method is determined, and checkback of the hydraulic condition of the optimized system is implemented.

Pipeline integrity management system is established by PetroChina Pipeline Company through research and discovery, according to the characteristics of pipelines managed. In this system, comprehensive system documents and standards of pipeline integrity management system are formed; technology system, including data collection, high consequence area identification, risk assessment, inspection and evaluation, maintenance and repair and other key technologies, is established. Through research and application of the system, the philosophy that "risk can be controlled, accidents can be prevented" is basically realized, which lead to the improvement of pipeline integrity management.

As appurtenance of existing building drainage systems the septic tank may be the single most important component used in the onsite treatment and collection alternatives. The passive - energy free - septic tanks provide the most cost efficient form of primary treatment available for nonindustrial sewage. Because the septic tank is an essential ingredient to the success of building drainage systems and a failed septic tank can present major inconvenience and pose a serious health threat as well as are failing to adequately protect the environment, it's engineered design, practical application and maintain addresses the central problem. In this paper the existing problems of the septic tank system currently using in China are summarized by means of field survey and investigation. Also via the field experiments, the treatment efficiency of COD_cr has been made an appraisal. The application of the computer simulation to analyze of sewage flow characteristic inside the septic tank is clearly described. Afterwards, some new ideas and methods are presented in order to improve the performance of existing system.

Thoroughfare of Hong Kong-Zhuhai-Macao Bridge is designed as an underground tunnel transport hub to meet the increasing traffic challenge in Chu Chiang Delta, where consists of Hong Kong, Zhuhai and Macao cities. Underground tunnel was considered as the only alternative due to the area condition, limited environment disturbing and complex geographical conditions, and pipe ring was taken into account as proposals supporting underground excavation in this project. This paper will introduce the construction requirement and then focus on two pipe jacking design proposals. Advantages and disadvantages of these proposals will be discussed by comparing different technical parameters.

The offshore riser and pipeline with an unsupported span are usually subjected to the vibration due to vortex-shedding. To analyze the vortex-induced vibration of offshore pipelines in steady current, an elastically supported rigid hollow cylinder is used as a calculation model with single freedom. The fluid forces acting on the cylinder are divided into lift and fluid reaction. A simplified method to analyze vortex-induced vibration of cylinder is established. The method transfers the structural vibration differential equation into algebraic equations and the empirical formulae about fluid force coefficient are put forward. The results calculated by above method indicate that the vortex-induced vibration of a cylinder is mainly controlled by reduced velocity, usually, the locking-in phenomenon occurs when the reduced velocity falls between 4.0 and 9.0, and the maximum vibration amplitude occurs when the reduced velocity falls between 6.25 and 7.5. The method presented in this paper is a feasible one to predict the vortex-induced vibration of a cylinder.

Based on AutoCAD platform, this paper develops hydraulic calculation software of urban water supply networks by using Visual LISP. It consists of five modules, such as numerical calculation module, display module, query module, analysis module. The numerical calculation module included two parts: demand allocation and hydraulic calculation. The model can get the data and graphic information of water networks directly from the graph by using the developing ability of Visual LISP. With the knowledge of Graph Theory, the model can automatically get the incidence matrix, thus realize the hydraulic calculation. To a certain extent, it brought convenience for the hydraulic calculation. Node (H) equations method is used in the hydraulic calculation. The application on an urban water distribution network showed that the software was feasible. Therefore, it is very useful and can become an effective tool in hydraulic simulation of water supply networks.

Present experiences on urban runoff pollution control in China are introduced. Problems and difficulties of presently applied measures by building detention tanks for solving combined overflows and first-flush pollution are analyzed. An innovative in-line intercepting double-layer drainage system consisting of double-layer pipe and double-layer manhole is presented in details. The preliminary experimental results indicate that first flush of storm water flowing through the upper layer channel can be intercepted into the under-layer channel via the interception hole which is set in the interlayer board, and the flow of first flush intercepted depends on the size of the interception hole. The shape of the interception hole and the pattern how it is placed on the interlayer board can influence the intercepted flow and its variation over time to some extent. The benefits and prospects of engineering application of this innovative double-layer sewerage system in the future are analyzed as well.

Trenchless technologies (TT), unlike open cut trenching, offer the potential to install, maintain and refurbish buried utilities without the need to close long stretches of carriageway. Recent studies indicate that carbon emissions associated with trenchless installations are far smaller, and trenchless installations are more sustainable, than trenching. Yet utility companies, and their contractors, routinely shun trenchless technologies due to the perceived risk of damaging previously undetected third party assets. Mapping the Underworld (MTU) seeks to create a multi-sensor tool, and a new philosophical approach to underground mapping, to mitigate such risks and facilitate the routine adoption of TT. The novel approach is now being developed through the proof of concept stage towards field trials and the results of these proving trials form the basis of this paper. Moreover such street works, like all construction, repair, renewal and maintenance projects, must be reviewed in terms of a sustainability assessment framework to explore their real costs and benefits to the society on behalf of which, as ultimate ‘users' of the facilities, the works are being carried out. This paper seeks to integrate the findings of a highly multi-disciplinary technology-based project with a wider research programme on the context of effective and efficient working in the streets. The lessons drawn from this programme of research extend to all aspects of pipeline engineering.

The ground in which utility service pipelines are buried inevitably controls, to a large degree, the structural performance and progressive deterioration of the pipelines themselves. In a parallel programme of research to the UK Mapping the Underworld (MTU) project, a study of the fundamental properties of the ground, and how they change with the seasons and local physical and chemical contexts, is being conducted at the University of Birmingham, UK. While the results of this study feed into both the operational protocols for the MTU multi-sensor location device and the associated knowledge based system (KBS) that is being created to aid its deployment (both topics being the subjects of separate papers to this conference), the suite of complementary research projects on the ground and its properties provide valuable insights to the pipeline engineer. Geophysics is being used by the research team to explore the state of the ground with the aim of highlighting areas of concern for the structural health of pipelines buried in the ground. Studies of cast iron pipeline corrosion mechanisms have focussed on the changes that the reaction products cause to the surrounding soils, with a particular emphasis on clay soils, and one interesting finding is that these clay-iron reaction products can make the pipelines ‘invisible' to standard geophysical location devices. Moreover there are other features in the ground that are being targeted (voids, ground wetting and softening due to leakage, ground weakening due to progressive erosion), and these features effectively make the ground more or less ‘visible' to geophysical technologies. Alongside this work, bespoke tests have been developed for use on site to ‘calibrate' the geophysics, thereby enhancing the signatures of the features. This paper introduces these parallel research projects and draws out the important findings for pipeline engineers charged with establishing the condition of existing buried assets.

Automatic directional drilling tools are the tools which are closed loop control system with underground, underground take the initiative to correct ramp to achieve and coincide with the design trajectory, with a high technological content and advanced drilling tools. In the steep structures formation of large deviating force, directional drilling tools have been the rapid development and wide application. In order to direct the design of automatic directional drilling tool manufacturing and field applications, base on fully understanding of automatic directional drilling system structure and working principle ,using the crisscross bending method and formation of natural deviating force of the general law, calculating the total force which change the inclination and the azimuth, summed up the directional drilling tool automatically deflecting the impact of factors that guide the automatic directional drilling tools for the optimization of the design to provide a theoretical basis.

Many projects of long-distance water transmission have been built to resolve the problem of the shortage of urban water resources. But, the water hammer will be presented as the result of excluding air fleetly at the process of water-filled at first time in the projects of gravity flow. The process of water-filled at first time is divided into 3 steps according to the target of operation in project, filling water, excluding air and enhancing flow, which are benefit for the application of study result and guide of operation. In the first step, the target of filling water is to exclude part air in the pipelines and to outflow water at the end of pipelines. The key parameter of control is the flow rate which is solved by the method of flow of non-collecting air. In the second step, the target of excluding air is to exclude all the air from air valve in the pipeline by water pressure, the key of this step is the operation process. In the third step, the target of enhancing flow is to increase velocity of flow for reaching the design flow. The method of filling water at the first time has applied in the long-distance water transmission project located in the northeast of China, the operation status shows that the method could ensure the security and order in the process of water-filled at first time.

There are two commonly methods to manufacture impregnated diamond bits at present: hot-pressing and the non-pressure immersion method. In order to test the performance of China impregnated diamond bit by hot pressing method and Ukraine bit with AKTM embedding in the lip surface by non-pressure immersion method, two types of drill bits were tested by the indoor bench drilling experiment and in geological core drilling located Jibaomiao mining area, using the same drilling parameters and the same granite formation which drillability was up to level 9.Test results showed that, the average mechanical penetration rate of China bit was 4.76 m/h when Ukrainian was 1.66 m/h; the average life time of China bit was 56.31m when Ukrainian was 25.38m. This paper analyzes the failure reasons of the two types of bits from the manufacturing technique and structure design. The research of this paper contributed to the design and manufacture of small-bore impregnated diamond bits.

Based on the Φ711mmx10.3mm and Φ720mmx14.2mm 360MPa spiral submerged-arc weld pipe, adopting the processes of 900°C induction quenching, 950°C induction quenching & 480° tempering, the induction bends were manufactured. According to the processing technic and design feature of spiral seam bend, the destructive test sampling plan of spiral seam bend was proposed. Through the mechanical property tests and design proof test, the spiral seam bends were studied and evaluated. The results of mechanical property tests show that the property of quenched bend is close to that of quenched and tempered bend, which indicates the material of weld pipe is not very sensitive to the heating process in a certain temperature range. Compared with mother pipe, the tensile strength of base metal of bend increases, and the tensile strength of welded joint decreases appreciably. The impact toughness of base metal and welding seam of bend increases. The design proof test shows that the bend does not rupture at the computed proof test pressure. For the configuration of bend, because of the effect of bending process, the welding joint unfitness occurs in the intrados of Φ711mmx1 0.3mm spiral seam bend.

Nowadays the Analytic Hierarchy Process (AHP) approach is often applied to risk assessment of city gas pipeline. However it cannot reflect the fuzziness and uncertainty of the factors. In this paper, an uncertain AHP is applied to the multistage synthesis fuzzy assessment of pipeline using the principle of uncertain judgment. It sets up an objective optimization model for the unknown factor weights among the judgment matrix of uncertain hierarchy analysis, seeks the optimized value of interval weight and obtains the assessment result for pipeline risk grade by grade membership function. The practical application validates the feasibility of uncertain analytic hierarchy process for the risk assessment city gas pipeline network.

In the modern petroleum industry, pipeline is one of the safest and the most economical methods to transport lager quantities of oil and natural gas. However, accidents of pipelines cased by the third-party interference are recorded in the newspaper. The accidents always exert catastrophic influence on our social life and environment, at the same time, they cause a great deal of economic loss. The reasons caused the third-party interference are complicated and it occurs randomly, so that it is hard to be forecasted or controlled the third-party interference in advance, and it has become a serious threat to the safe operation of long pipeline transportation. This paper conducts the research on the risk management of long natural gas pipeline transportation. The fault tree analysis provides reliable evidences for risk assessment. On the basis of investigating and studying, taking "gas pipeline be damaged by third-party interference" as top event and considering 31 basic events, a relatively integrated fault tree model is established. Then the results of qualitative analysis on this fault tree are discussed. Based on this conclusion, suggestions for prevention and control measures of gas pipeline third-party interference are provided.

The extension method can reflect a sample's compressive level from two angle of qualitative and quantitative by constructing its model. Based on this theory, this paper investigates the risk zoning method of geological hazards of a coal bed gas pipeline construction site in Weibei area, China. According to the development characteristics of the geological hazards near the construction site, the index system and grading standards for geological hazards risk evaluation are put forward in the aspects of geological hazard's activities in history and future level of development. After using a simple correlation function to determine the weight of evaluation factors, the degree of geological hazards risk in pipeline construction site can be comprehensively zoned. The result indicated that the zoning results are in accordance with actual situations. It supplies the basis for the work of routes choosing as well as geological hazards prevention and reduction. As a result, this research can serve as a reference of geological hazards risk evaluation for similar pipeline engineering projects.

Fatigue reliability of submarine pipeline span under the wave is study based on first passage theory of stochastic vibration and reliability theory. A failure criterion is established by fracture mechanics principle. The fatigue failure of pipeline span is coined as a first passage problem. The long-term stochastic sea state is treated as several discrete short-term states which are described by Rayleigh distribution. Modal approach is used to derive the stress response spectrum of pipeline span under the short-term states. The ratios of expectation crossings of span's stochastic stress responses under the short-term states are calculated by using Poisson model, and then the total fatigue reliability is ascertained. The effects of span length, design life, initial crack size, fracture toughness and crack parameters to reliability are studied by examples. Fatigue reliability changing curve can be used for conference of submarine pipeline design.

As natural gas is flammable and explosive, gas pipeline accidents would lead to vicious consequences such as fires and explosions and bad influence in society. And as the gas transmission is interrupted, the accidents will also impacts on regional economic development and social stability to a great extent. Risk-based Inspection (RBI) which has arisen and developed in western countries in the past 30 years, is a system management concept and method that in pursuit of the unification of security and economics. Risk-based Inspection is one of the key technologies of risk management of pipelines. Application of RBI is in a wide range, but it is still a new attempt to apply RBI in the risk assessment of the gas pipeline systems at present. In this paper, the quantitative risk evaluation of RBI in API 581 was in-depth analyzed and researched, and the factors of third-party damage of gas pipelines in the failure probability assessment part were taken into account, then the RBI quantitative risk assessment model of gas pipeline system was established. A RBI quantitative risk assessment of one certain gas pipeline system was done by using the model, and the result of the risk ranking was carried out, which provided theory basis for the operation and management of the pipelines.

According to the basic principles of risk assessment and the characteristics of construction and operation phases of underwater gas shield tunnel, Concluded the method on the risk rating assessment of construction and operational phases of underwater gas shield tunnel. Combined with qualitative and quantitative, and analyzed all risk factors legitimately, the risk control and management would be effectively . Described the specific application of risk assessment theory impressing on the construction of Xi-Jiang shield tunnel.

The fault tree of the pipeline was studied by investigating the failure modes and statistics of pipeline accidents of PetroChina. After a quantitative analysis of the impact factors for different failure modes, a Quantitative method for calculating the failure possibility of pipeline was established. The result was used to improve the most widespread pipeline risk assessment method - Kent scoring method. It can give comparable quantified description of the pipeline risk under current operation condition, and can give further support for decision-making of integrity management.

The paper discusses the basic theory of risk assessment and improves the method proposed by W. Kent Muhlbauer through analyzing and studying a large number of documentation, including the method of risk assessment and development of system. The risk assessment index-system is determined by the method of multiple analysis and Delphi. Based on the method, the risk assessment system of city gas transmission and distribution networks is developed, which realizes the functions of risk source management, risk analysis, system management and so on.

On the basis of the characteristics of urban gas pipeline accidents, the risk assessment method based on domino effect is proposed. The domino scenarios are determined by analyzing major hazards that could trigger domino accidents of urban gas pipeline. Three risk assessment models of domino accidents are established: fire radiation model, explosion shock model and explosion fragment model. Then the probabilities are calculated to get the risk value and the influenced area of incidents. It is suggested that the GIS system of the urban gas pipeline be set up to carry on risk analysis and safety management of pipeline and surrounding hazards in case of the domino accidents.

Risk assessment is one of the important technology to ensure the safety of the long-distance oil/gas pipeline, and calculating the failure probability is the important part of the risk assessment, then the veracity of the failure probability impact the rationality and applicability of the result of the risk assessment. Minimal cut set system of fault tree for the third party damage of oil and gas pipelines is calculated based on search algorithms of Petri nets minimal cut sets, and laid the foundation for fault tree analysis system considering the correlation. The analysis model of failure probability for basic event parallel system of minimum cut set based on the proposed Hamath QiuEr accumulate operator is proposed, meanwhile, sorting combination method of the basic event attributes and classification is established for solving failure probability of many basic events. In addition, correlation analysis of failure mode under the action of random disturbance sources is discussed; failure correlation analysis model of minimum cut set is established based on the proposed MGL for solving failure probability of failure mode series system comprised by the minimum cut sets.

In recent years, with the development of oil/gas pipelines transmission, there have been over 60000km long-distance pipelines in China. Most of long-distance pipelines transmit gas or oil with high pressure and high rate of flow. And these pipes are often built in areas with adverse natural condition where many accidents occur and cause serious consequence. Therefore, in order to improve pipeline safety, HCAs recognition of long-distance oil/gas pipelines is a very important task. In this paper, impact factors system of HCAs of oil/gas pipelines is established on the basis of Expert Scoring Method of HCAs recognition. Three aspects, which are leaking media, damaged objects and control of consequence, are taken into consideration. According to the impact on consequence, weight is given to corresponding factor and assessment grade of each base event is established. the impact factor system can make HCAs recognition procedure rigorous and systematic and guarantee a reliable recognition, which is helpful to a reasonable allocation of resources and scientific decision -making of pipeline integrity.

Safety assessment of underground city gas pipelines is an urgent problem in many cities in China nowadays. To assess the safety of underground city gas pipelines, fault tree was set up to find the fault modes by qualitative analysis. Quantitative analysis method was used according to the basic events so as to gain the risk probability of gas pipelines. Through actual engineering example, it proved that the assessment method can be used both for gas pipelines safety assessment and for safety comparison in different cities and regions.

Based on natural gas hazard properties analysis, this paper systematically summarized the types of the natural gas pipeline leakage accidents and analyzed the toxicity and flammable characteristics of natural gas pipeline leakage with the help of quantitative risk analysis Software DNV SAFETI(Software for Assessment of Flammable, Explosive and Toxic Impacts). According to the flammability analysis of natural gas, leakage can be caused by jet fire, fireball and explosion. Through the corresponding calculation model of SAFETI, risk degree of explosion and its consequences after formaldehyde leakage accident were calculated, which is truly useful to predict and to prevent natural gas pipeline leakage accident and to reduce individual risk and social risk respectively.

Applied a gravel drainage layer around underground pipeline. Based on the Finn model, the numerical liquefaction experiments ware completed separately in the non free field and the gravel drainage layer non-free field. Confirmed the anti-float effect of the gravel drainage layer method. Calculations indicated that, the gravel drainage layer field around the underground pipeline will not liquefy, the excess static pore pressure obviously reduced at far place from pipeline in liquefaction field, the pipeline uplift obviously reduced, the level drifting reduced. The gravel drainage layer has enlarged the overall quality and the rigidity of the pipeline, increased pipeline's stability. Researching results will provide a theoretical and experimental basis for the design of underground pipeline through the liquefaction soil layer.

The earthquake happened in WenChuan city, SiChuan province of China on twelfth June 2008 had greatly impacted the integrity of LanChengYu pipeline, which is the only way of providing product oil to SiChuan province. The pipeline designers have paid more attention to the threat of earthquake after that. This paper reviewed the traditional methods of calculating pipeline failure frequency caused by earthquake, and pointed out their shortcomings. In addition, a new method was provided. Firstly researchers should calculate the additional strains of pipe caused by earthquake which related to the peak ground acceleration (PGA). The method of additional strains calculation was provided in the Chinese industry standard SY/T 0450. Secondly the uncertainty calculation was conducted to get the rule of distribution. Finally the additional strain was compared to the allowable strain of pipe, and the probability of exceeding is the pipeline failure frequency caused by earthquake. Further An example was followed. The parameters needed were listed, and the pipeline failure frequency along the station was illustrated. The result may be useful to pipeline designers.

Buried pipelines are vulnerable to damage caused by flotation as the soil liquefies during an earthquake. In this paper, in order to analyze the cross-sectional deformation of large-diameter and thin-wall (φ1016x21mm) buried pipeline under liquefaction-induced uplift force, a comprehensive three-dimensional pipe-soil coupling model, based on pipe-soil Interaction and thin shell theory, is developed. Utilizing the model, uplift response of buried pipeline under different conditions are simulated and the effects of several important parameters including width of liquefied zone, ratio of diameter to thickness (D/t), burial depth, and strength of soil spring are studied. The results show that the maximum ovality ration and strain of pipeline under liquefaction-induced uplift force increases with increasing width of liquefied zone, soil spring strength, burial depth and ration of diameter to thickness. Width of liquefied zone and soil spring strength are critical parameters, which have large effect on deformation of buried pipeline, however, the ratio of diameter to thickness and burial depth of pipeline affect the uplift response of pipeline slightly. According to the results obtained, some useful suggestions for the design of large-diameter buried pipelines in liquefiable soil are given.

It is often necessary to study on the mechanic behaviors of the buried pipelines subjected to seismic excitation, because the ground motion will inevitably endanger the nearby underground pipelines. In order to analyze the dynamic response of the underground pipelines during the earthquake, the three dimensional seismic records were selected and the pipe-soil interaction was considered for the numerical simulation. Three major factors were discussed, respectively. These factors included the earthquake intensity of the site, the end restraints and the boundary conditions of the underground pipelines. Simulation results show that the seismic response of the pipeline resulting from the axial earthquake input motion is biggest, and consequently the axial seismic wave has more influence on the underground pipeline than the other two-dimensional seismic waves.

This project focuses on involving both graduate and undergraduate students from the Construction Engineering Management Technology (CEMT) Program at Indiana University-Purdue University (IUPUI) in a New Product Review (NPR) process that is being undertaken for the Department of Public Works (DPW) of the City of Indianapolis, Indiana, U.S.A. Within the context of this program, CEMT students provide technical evaluation of new materials, technologies, and processes to the City through a University — Public entity collaboration. As the City of Indianapolis continuously updates and/or adds to its infrastructure, new materials, processes, and technologies (called "products" overall) are frequently submitted for adoption to the City by various outside vendors. For the DPW, these are often products that deal with sanitary sewer and storm water infrastructure systems. Previously the City's "new product review" process was facilitated by outside consultants. As the City grew, DPW began to experience a need for help with the process from a non-partial third party for review and approval of such new "products". So, when the City was presented with a system that would provide excellent experiential learning and research opportunities outside the classroom for our students, as well as, provide new "product" evaluations resulting in lower costs, shorter review times, and a number of other benefits for the City, they were happy to entertain the idea. Thus a meaningful collaboration between the City DPW and IUPUI/CEMT was born. This paper focuses on how the process is being implemented, what kind of reviews have been conducted to date, and how has this undertaking impacted student learning and in which ways.

Ground subsidence caused by metro shield structure construction has serious effect on surface building facilities. In metro shield construction activities, the tunneling process will disturb the balance of original soil, which is likely to be magnified or inhibited by the nonlinear characteristics of geological condition, formation morphology, formation thickness, porosity, moisture content, and other factors. Such disturbance leads to the macro subsidence process with chaotic characteristics. Through the appliance of CC chaotic prediction method and the combination of finite element and fractal kinetics theories, the essay does research on the dynamic characteristics of shield construction settlement, and provides a technical support for the ground subsidence formation mechanism and risk control.

Cast-in-situ tubular piles with large diameter have great flexural rigidity and low consumption of concrete per meter. This characteristic makes it suitable for the bracing system of a foundation pit, especially among the coastal soft clay zone. Herein, through the successful design and construction of cast-in-situ tubular piles in pit excavation engineering in Wenzhou and the analysis of the surveillance data, it can be concluded that large diameter tubular piles have promising prospects in supporting pit excavation of soft clay area. A new pile tip has been proposed and used in the project.

Combined with the engineering practice of excavating a double-track railways tunnel in red clay, based on both numerical calculation by ANSYS software and monitoring data to study the variations of vaults subsidence, moment and supporting axial force in process of excavation. The results show that the ratio of vaults subsidence caused by excavation section 1 accounts for whole subsidence was about 36%, the vaults subsidence vs. time normally was a nonlinear uplifted curve with a final stable, the time of closing the tunnel invert play a decisive role in controlling vaults subsidence, closing the invert as soon as possible could greatly reduce the final subsidence. In the whole excavation process, the maximum moment appeared in the vault, the axial force caused by former excavation side (right side) was larger than that latter excavation side (left).

The traditional shield construction technology has many defects, such as intensive labor in the process of assembling segments, high cost of the bolts, cannot stand inner water pressure directly and so on, so the shield tunnel cannot be applied in the field of tunnels rapidly that can stand inner water pressure. In recent years, post-tensioned pre-stress technology of concrete has been introduced in the production of shield tunneling segments and the assembly of segments at home and abroad, which extend the shield tunnels application in hydraulic field. Based on the literatures and the existent researches, the paper takes the formation of a region in Beijing as the engineering background. Firstly, according to the load-structure method, the probability-based limit state design and the concept of prestressing degree, prestressed & precast concrete segments had been designed for a water conveyance tunnel. Secondly, in reference to the prestressing technology of domestic tunnel standing inner water pressure, a encircled anchorage technology was chose to use, meanwhile, in order to reduce the testing cost, these existing segment moulds were transformed to produce these segments to meet the testing requirements. Thirdly, it was the first time to carry out the water pressure test for a full-scale and horizontal model of prestressed & precast concrete segmental lining in China, the results were satisfactory and could meet the design requirements. In the end, the mechanical properties of prestressed & precast concrete segmental lining at 0.5 MPa inner water pressure were analyzed by the three-dimensional finite element method, the theoretical results approached the full-scale experimental results. Some promising research results were obtained.

The interval tunnel between the Ximen station and the Drum Tower station of Ningbo metro line 1 goes through the national reserve cultural relics of Tianning tower. This interval tunnel is constructed by shield method. To ensure the safety of the Tianning tower, the impact of shield construction on the tower should be evaluated. Two kinds of FEM software are used in the safety assessment to analyze the additional deformation of the Tianning tower caused by shield construction. In order to reduce the differential settlement and incline of the tower, the isolation piles protection is considered to use as protection method. For the different calculation schemes of pile location, pile length and pile diameter, the protective effect is analyzed and the measures are proposed.

The launching and arriving of shield machine are the key aspects of shield tunneling when crossing rivers, which directly affect both shield driving and the stability of working shaft. Based on the background of Xijiang crossing project of gas pipeline network in Guangdong province, this paper mainly illustrate the key starting and arriving procedures of slurry shield, and the numerical simulation method is used to analyze the stability of shield excavation face under different horizontal and longitudinal consolidating range. On this basis, combined with other engineering practice, a reasonable reinforcement range is also proposed in the shield starting and receiving section.

There are many factors involved in the maintenance structure of shaft in shield tunnel, and the interaction between various factors is complicated. Combined with starting shaft construction of Xijiang River slurry shield tunnel, this paper analyzed the characteristics and applicability of common foundation maintenance structure, and proposed a composite support consists of diaphragm wall and bolt-shotcrete. A numerical simulation method was used to study the displacement regulation of soil surrounding the maintenance structure and ground settlement features under different excavation footage when using composite support. Construction results show that this composite support effectively ensure the safety of shaft construction.

Based on data collected in tunnel boring machine (TBM) construction in Beijing subway, soil settlement prediction models for sand formations are analyzed and verified. Through the analysis of Peck's formula, the paper points out that the precondition is to determine the coefficient of settlement groove width (i), while i is further controlled by the maximum settlement of single tunnel (δ_1max). By using the settlement equation of Takeyama Takashi, δ_1max can be calculated directly, but the elastic modulus (E) should be an equivalent value that represents all the soils involved. In the calculation of the coefficient of settlement groove width (i) by using O'Reilly-New method, the results is largely affected by the formation parameters. In order to find an ideal model to predict the settlement in TBM construction in Beijing sandy formation, modified calculation methods of E and i are recommended. The results show that the maximum settlement in the ground surface, the total width of settlement groove and the settlement curve in the cross section match monitored data very well. For double parallel tunnels, the settlement at any point can be calculated by adding individual settlement generated by each tunnel construction, and each of which can be calculated by using the formulas of Peck and Takeyama Takashi. But the settlements at the centerline of each tunnel are different. The amount of settlement is affected by construction sequence of the two tunnels. The earlier the tunnel is constructed, the larger the eventually settlement is.

Shield tunneling leads to soil displacement around the tunnel and ground settlement, which makes it necessary to estimate the displacement and settlement. Many research works have been done for it before so that many achievements were obtained. However, the soil displacement and ground settlement tunneling with super large earth pressure balance machines (EPBM) is studied rarely because it is seldom used in the world. But it has been used in urban underground transportation constructions in recent years and has broad prospect. Excess pore water pressure will generate in the front soil because of cutter's pressure to it in high water content earth layer. Pore water will dissipate after shield thrusting stops and then earth pressure will decrease. Furthermore, soil displacement and ground settlement will take place. This phenomenon was more obvious to the super large EPBM than less one for its super large cutting area. Through monitoring data and tunneling parameters in engineering cases, influence rule of shield tunneling parameters to earth pressure in front of cutting face and excess pore water pressure can be found out. Meanwhile, the relationship of fluctuation of excess pore water pressure and ground settlement also can be found out. And then, ground settlement can be decreased by adjusting the tunneling parameters. The void filled incompletely behind shield tail can be ascertained by inverse calculation with image method. According to the void, grouting amount may be adjusted to decrease the ground settlement. Two engineering cases in Shanghai show the method is valuable to the following engineering.

Relied on the South-to-North water diversion engineering of the Beijing south main channel, analyzed the construction process of the shallow double tunnel beneath the buried gas pipeline by numerical simulation method, discussed the different effects of the buried gas pipeline which were caused by three kinds of hydraulic tunnel excavation plan, and sieved the optimal excavation plan. The results showed that, the maximum settlement and the maximum stress caused by the full-face method is smaller than that caused by the reserved core soil method. While using the same excavation method, double tunnel excavation staggered distance excavation is better than the parallel excavation. The key observation range of pipelines is along the pipe axial direction extending about 3 to 5 times the hole diameter from the center of the pipeline to both side, when the tunnel excavation face is about 3 times the hole diameter before or after the existing pipeline position. When near pipeline 3 times hole diameter scope, the tunnel excavation should adhere to the principles of the footage short, the small disturbance, the frequently observed, and quick supporting. In the end, the safety of transmission gas pipeline is evaluated during the south main channel construction, and the some important reference conclusion is give for similar engineering.

It is necessary to analyze the influence of the subway construction on the nearby underground pipelines, because the excavation of the subway tunnels will often cause large deformation and thus brings about safety problems. This paper focuses on the deformation variety of the underground pipelines during the construction. Influences from five key factors which included the material and the buried depth of the underground pipelines, the horizontal distance and the cross angle between the pipeline and the subway tunnel, and the parameters of the insulating layer were discussed, respectively. Numerical simulation results show that the pipeline can suppress settlement of the soil layer to a certain extent, and the insulating layer contributes to damage prevention of the underground pipelines.

Numerical analysis and model testing are the primary methods in the study of shield tunneling. Numerical analysis has the advantages of repeatability and low cost, but it is difficult to simulate the interaction of multiple components important to the construction process of shield tunneling. Model testing can avoid many shortcomings of other research methods, and it is closer to actual construction. In the model test of shield tunneling, a shield model is necessary. In this paper, typical shield model machines in China and abroad will be introduced first. Then four shield installations in Southwest Jiaotong University will be introduced with the function, characteristic and test processes described.

High chamber earth pressure will lead many difficulties when shield driving in gravel layer. To overcome these shortcomings and enhance the efficiency, the contractor usually wishes to decrease the chamber pressure. To examine the basis of the make up of driving resistance, a three dimensional numerical model is built and the resistance distribution around shield is revealed. By analysis of field test data, the relationship of cylinder thrust, chamber earth pressure and driving efficiency is obtained. The results show that decreasing the chamber pressure to a certain extent can achieve a high driving efficiency.

Trenchless pipeline directional drilling has been widely used in the pipeline crossing recent years. But the problem about serious drilling fluid losing often appears in drilling process because of large stratum of porosity. The characteristic of under-balance drilling is that the pressure of fluid in wells is less than stratum pressure, which can effective control the leakage of drilling fluid in wells and prevent stratum from polluted by leakage of the drilling fluid. Furthermore, the technology of under-balance drilling has advantages such as high drilling speed, less differential pressure sticking. The method of under-balance with the trenchless pipeline directional drilling has been researched in this paper. The selection of under-balance drilling method has been discussed, including Air drilling, Foam drilling, Atomization drilling and Aerate drilling. Advantages and applicability of under-balance method in pipeline directional drilling construction are illustrated. The problem of drilling fluid selection, negative pressure designing, density of drilling fluid calculating and drilling methods in construction has been introduced and analyzed, and some solutions have been obtained. Under-balance drilling method provides a new method and a reference for construction of pipeline directional drilling.

Trenchless pipeline directional drilling technology has been widely used in pipeline crossing. However, it is always inevitable to cross the unfavorable stratum during the pipeline directional drilling construction, which has become a difficult problem for pipeline directional drilling crossing technology and hinder its development and application. Therefore, unfavorable stratum including high-hardness rock, pebble gravel stratum, sand and soil stratum are researched and their lithologic character is analyzed. The Horizontal Directional Drilling (HDD) technical difficulties under the circumstances of unfavorable stratum are summarized and the possible adverse effects during construction process are predicted. For wellbore collapse, drilling fluid leakage, wellbore instability and low efficiency of breaking rocks, technical program is proposed on the basis of selection of drilling fluid, structure of stratum, drilling methods and method of using well casing. A new method is introduced for directional drilling crossing unfavorable stratum, which can decrease the construction risk in the condition of unfavorable stratum, reduce construction cost and guarantee construction period.

The middle Yangtze River is about 950km, the bed and two banks of which are composed of loose accumulation horizon of the Quaternary. No-dig directional drilling is suitable for the bed and banks. When drilling in different soil layers, no-dig directional drilling may cause some engineering geological problems as well as environmental geological problems such as collapse crater, ground fissure, piping, environmental pollution. Soil property is the internal cause of environmental geological problems while construction factor the external one. Environmental geological problems could be prevented from happening by both improving the soil property and controlling the construction parameters.

Highway, railway, waterway and pipeline are ways to transport oil. The pipeline has irreplaceable superiority, such as high throughput, low energy consumption and low cost. So the pipeline is the artery of energy source of national economy and very important to the development of social economy. When the pipeline is constructed, crossing some rivers is inevitable. If the crossing method and engineering management were unreasonable, the environment will be damaged, especially the pipeline may be destroyed seriously by the third party damage. Recently, the techniques of design, construction and management of pipeline river-crossing have made a great progress in the world. But pipeline river-crossing is still a technical problem, it needs hydrological research and analysis, geological prospecting and scheme selection. Qing-Tie crude oil pipeline locates in the Northeast of China and has been operated 35 years. It crosses 121 rivers. In these rivers, most sections of the pipeline are attacked by water directly because of the covering soil was washed away. Some sections are baring and hanging tens of meters. It is hidden trouble of security of operation. Especially the pipeline crosses Chai River in Liaoning province, it is laid by culvert of stone, once has an accident it can't be remedied. So remaking the crossing project scheme is essential. This paper has introduced the basic situation of Qing-Tie pipeline and Chai River. The stratum description, weather and hydrogeology, earthquake situation and the stability of bank are analyzed and evaluated. Heavy excavation, directional drilling, shield pushing and drilling blasting are compared by merits and drawbacks, construction period and engineering cost. Finally, the directional drilling is considered to be the best. The crossing horizon, embedded point, out point and laying parameters are worked out. The establishment and implementation of the project scheme is reference for the technique of pipeline river-crossing.

Designing the no-dig impactor by the method of anology, experience and actual test, it had a large cost and long-time cycle, and was hard to achieve the optimization. In order to research intensively the impactor work mechanism and describe piston movement laws in detail, physical model was established according to the actual conditions, finite difference method was adopted, thermodynamics and kinematics were applied. Using object-oriented programming, the no-dig impactor computerized simulation software was developed whose integrated development environment was VB. The software can calculate acceleration, velocity, displacement during piston running, pressure, temperature of the front and back air chamber at any time and the operating performance parameters of the impactor. The law of many factors influencing on the impactor performance can be found and the optimization of the impactor structure parameter can be achieved by the ergodic method by the software. Not only the no-dig impactor but also fully broken pneumatic DTH and breakthrough-type DTH are designed by the software.

With the increasingly widespread in the application of municipal projects with unparalleled advantages, pipe jacking construction technology during long distance is one of the most complex and quite difficult topics. The technical problems and measures to deal with that through of the pipe jacking technology during long distance were provided in this paper, including (1)appropriate construction methods were selected in accordance with comparative analysis and verification, (2)common problems, such as rotation of the jacking machine, correction, slurry leakage and ventilation, were handled with effective management and treated timely with frequent small adjustments instead of static or large ones, (3)measures were taken to prevent major technical problems such as insufficient jacking force, insufficient thrust force from working shaft and failure in following correct jacking direction. Integration of meticulous organization and information construction can be widely applied in the city's infrastructure.

Instability of hole wall has been a main technical problem in HDD, it could directly delay project process, increase costs of drilling projects. Therefore, if the instability of hole wall could be pre-estimated, it could be able to take appropriate precautionary measures in advance to avoid the occurrence of hole wall instability before the project construction. This paper analyzed the main factors that influence stability of hole wall, geological factors, factors of slurry and drilling's technique influence on hole wall stability was researched by mechanics analysis. On these bases, a new mechanics calculating formula about elastic-plasticity model of hole wall instability was derived, and then FLAC 3D numerical simulation software was used to simulate instability process of the hole wall. Based on above, the pre-estimation technology for instability of hole wall was gained finally. Engineering practice has proved that this pre-estimation technology is accord with fact and useful for project construction, it is worth to be applied to HDD projects.

Positive displacement motor is an effective power for horizontal directional drilling in coal mine. An experimental approach to test the performance of positive displacement motor is presented in this paper. Firstly, the experimental system is established and then three types of positive displacement motors are tested. Based on the analysis of the experimental data, the type B has been recommend as the optimum down-hole drilling tool for horizontal directional drilling in coal mine.

The structure character and working principle of down-hole motor were introduced, borehole technology of down-hole motor directional drilling were studied, including borehole technology principle, directional drilling method, technology flow, technology parameters, branch borehole technology, etc.. Some coal mine field application was taken as an example to do a simple introduction on down-hole motor matching equipment and technology promotion. The borehole technology and related result can be used as reference for directional drilling research and construction.

In order to solve the problems of collapse and pipe-sticking resulted from gravel stratum laid at the both sides of crossing curve and difficulty of controlling the BHA direction in long distance pilot hole construction, pipe-ramming and intersection are simultaneously applied. Ramming casing method can effectively isolate the gravel layer to avoid pipe-sticking, meanwhile intersection technology not only can avoid situation that the bit could not precisely drill into casing pipe located at the exit point during the process of one-way pilot hole construction, but also effectively reduce the length of the pilot hole drilling. The paper mainly describes a comprehensive application method and principle of both pipe-ramming and intersection, given an example of Sino-Russia Crude Oil Pipeline Heilongjiang River Crossing Project to explain practical effect.

The preparation and recycling of slurry is a very complicated and crucial task in large Horizontal Directional Drilling (HDD) river-crossing project. This paper introduced the successful and advanced experiences of the utilization and management of slurry in large HDD projects in China. Different property requirements of slurry in different periods of the project are discussed. Research is focused on the recycling system of slurry, including the filtration of slurry which returned from the drill hole, and how to add bentonite and additives in this filtrated slurry. The recycling of slurry can save a large amount of bentonite and additives. The disposal methods of waste mud in the job site were discussed, and two methods were recommended to be adopted to dispose waste mud. One is mechanical methods, using centrifugal machine; the other is chemical method, using chemical material to solidify waste mud.

Microtunneling construction method is one of trenchless technologies that can be possibly employed for a gravity sewer installation. Advantages of utilizing a microtunneling include not only superior grade control-ability and direct sewer pipe installation without a casing, but also other common benefits found from a large family of trenchless methods. Although microtunneling technology has made significant advancement overcoming various technical challenges and site conditions since its introduction in 1980s, the failures during installation process have been periodically reported. This paper discusses potential failure factors that might occur during a microtunneling construction. This paper also presents a failure factor analysis based on field data collected from a 24-inch vitrified clay (VCP) sewer construction using a slurry pressure balanced MTBM.

The characteristics, difficulties, crucial steps and guarantee measures of the water pump station constructions including the high-depth Open Caisson and the large-diameter Pipe-jacking of artesian water intake pipe at the lower reaches riverside of Yangtze River are discussed. With regard to the silt-clay conditions of this project, the disadvantages of the high-depth Open Caisson construction are comprehensively analyzed, like gravity center unsteady, sinking too fast, axis displacement, quicksand, suddenly sinking, etc. The construction difficulties are thoroughly discussed and solved. The critical technologies of the caisson construction of the pumping station are sequently expressed, such as the combination of the wet and dry constructions, the measures of preventing quicksand, the correcting measures of displacement and inclination, and the measures of sudden sinking avoiding, etc. Meanwhile, the disadvantage factors of the large-diameter Pipe-jacking construction with long-distance in mollisol are entirely analyzed, including the instability collapse, the pipe axis offset, the jacking force insufficient and the damage to the dike of the Yangtze River, etc. The guarantee measures of the Pipe-jacking construction are presented in detail, for example the adjustment of the slurry pressure, the increasement of the anti-friction pulp and the intermediate jacking station, the alteration of the cement parameters, etc. Ultimately, the Open Caisson reached the intended depth directly at one time, the jacking pipe reached the specified salvage point smoothly, and both of the axis offset and the surface subsidence were controlled within a relatively small range. This study provides valuable and succesful experiences for the application of Open Caisson and Pipe-jacking trenchless technologies in the riverside areas.

As one of the types of trenchless excavation, pipe-jacking tunnel is being popularly adopted in the fields of municipal pipeline projects and others'. However, it is rare that the technology of pipe-jacking tunnel is used in petroleum and gas transmission engineering. Taking Sheshui River Pipe-jacking Tunnel that is part of Second West-East Gas Transmission Pipeline Project as example, the Plaxis 3D finite element software was utilized to analyze the stress distribution around the tunnel and settlement features after excavation, which would be useful to guide the safety control of construction. The results showed that the lining structures of pipe sections can generally meet the needs of construction in three different buried depths (13m, 18m and 20m), but the maximum settlement displacement would reach to 1.5–2.0 cm even 2.5 cm in some simulation zones, which called for the enhancement of settlement monitoring.

As one kind of drilling fluid additive, LG vegetable gum is easily obtained, comparatively cheap and harmless to the environment. This paper presents its performance parameters, action mechanism and successful practices in several horizontal directional drilling projects with the purpose of pipelaying. LG vegetable gum can be acquired from the leaves of natural Lauraceous plants. It has good filtration control ability, excellent lubricating capability and obvious anti-sloughing effectiveness. Basing on the lots of lab tests, its optimal amount in drilling fluid was determined as 2.0 weight percent. Its performances had also been confirmed by several core drilling engineering projects. Then the authors analyzed the fluid loss control and lubrication mechanism of LG vegetable gum. It has dual action mechanism of none-anionic and anionic filtration reducers for it has plant fibre and polysaccharose synchronously. Also it showed outstanding lubricating performance because it contains fat acid such as oleic acid and linoleic acid. Finally, the thesis presents the applied effectiveness of LG vegetable gum in varied horizontal directional drilling projects with the view of pipelaying such as Lumo Road project, 4^th Gongye Road project and Tianxingzhou project which crossed the Yangtze River in Wuhan, China. It successively conquered technical challenges of friction decreasing in cohesive soil, borehole stability in water-sensitive clay and anti-sloughing in borehole with the diameter over than 1200 mm. We can see a promising future of it.

Today, oil pipeline leakage accidents have occurred frequently all over the world caused by corrosion damage and resulted in a lot of loss of life, economy and environment, so integrity management on pipelines can bring huge economical and social benefits. This issue summarizes the difficulties of traditional pipeline repair methods, i.e. need repair after excavation, big workload, the high cost of the project and even the impact on traffic, amenity and citizens' life and proposes the appraisal thought for the trenchless corrosion detecting based on the analysis of corrosive factors. There are some existing common methods of trenchless corrosion detecting, including leakage flux analysis, Ultrasonic analysis, potential gradient method, PCM detecting buried pipeline leakages, identifying anode corrosion tendency points, C-scan locating fracture spots at anticorrosion and thermal insulation layers analysis and metal corrosion loss method of detecting remained pipe wall thickness, etc. This issue analyses the adaptability of these methods for the pipeline maintenance and repair from the corrosive factors and circumstance and provides scientific advice and guidance for the security and reliable operation based on the advantages and disadvantages of these methods.

The conventional oil-based used in horizontal wells of Daqing Oil Field is expensive and not environmentally safe, therefore, a study on Water-based drilling fluids that can give OBM like performance are needed. Through experimentation and comparision with oil-based emulsion drilling fluid, the MEG drilling fluid can stabilize shales by the same mechanism of balanced activity OBM. The MEG drilling fluid system developed in laboratory is tested in Daqing Oil Field. The laboratory experiment and field trial show that the MEG drilling fluid system is stable in rheological property and can effectively carry cuttings and clean wellbore. The lubricity and capacity of borehole stability of MEG drilling fluid system are comparable with OBM, better solid carry capacity. The MEG system is easy to formulate and condition. The MEG system is not poisonous and non-hazardous, the use of this drilling fluid could eliminate cost of oil contaminated drilled cuttings disposal. The MEG system can satisfy the needs of horizontal well of Daqing Oil Field and would be expected to replace the OBM in horizontal well drilling operation.

Some long-distance pipelines are planned and laid in loess plateau which is a typical kind of landform particularly in China. Complex geological condition in loess area makes great difficulties to pipeline construction using traditional trenched method especially to large gully crossing. In past decades, manual inclined shaft has been widely used for gully crossing, but it is inefficient and danger in construction. Recently, single-sided directional drilling (SDD) has been employed as a new method for loess gully crossing. Different from Horizontal Directional Drilling (HDD), SDD drills a bore hole through the gully from top to bottom and pipeline is installed by slipping along the hole. For its high efficiency, SDD has been regarded as the best selection for large loess crossing. But it is still limited in engineering because bore planning for SDD is almost determined by experiences which could induce unforeseeable questions or accidents in construction. This paper introduces the method for bore planning of SDD crossing including: 1) bore planning with linear drill path for loess gully with gentle slope and 2) bore planning with curve drill path for gully with steep slopes or unstable soil covering. Equations of main parameters for bore planning are derived and the application step is proposed as well. Finally, two typical cases of pipeline crossing loess gully in Yulin-Jinan gas pipeline are analyzed and bore planning design for each case is determined and conducted. Proposed method gives a reliable guideline for pipeline crossing loess gully with SDD and effectively increases construction quality and safety.

In the last 20 years, with the improvement of HDD crossing technology, it has become a popular and increasingly viable method for infrastructure installation in different areas within the construction industry, such as natural gas, electrical power and communication industries. Based on Geotechnical Generalized Plastic Mechanics, Establish the stability model of borehole that is multilevel reamed with FEM, a case is studied on Weihe HDD crossing of west-east gas pipeline engineering second-line. In the research, the tensile and shear failure criterion of geotechnical material is set simultaneously. Through the dynamic simulation of the shear and tensile stress, not only the stability judgment and instability failure process but also a mechanical estimate method to the stability of borehole could have been gotten, and the paper presents a suit of the precautionary measures. For the reaming and pipeline lying safely and fast, the available numerical solutions supply theoretical basis and technical support.

With better economic and social benefits, the directional crossing technique has been widely applied in many Pipeline-Crossing areas such as wire cable, drain pipelines and oil-gas pipelines. However, there is serous problem in string designing especially when at reaming, for the drill tools failure easily leads to a terrible result of the Pipeline-Crossing project. And because the string is also the power transmitter and fluid exchange channel, it is important for the rational design of directional crossing string. This paper proposes an analytical method of the string used in directional crossing reaming based on the String-dynamics Simulation Techniques (SDST). In recent years, with the rapid development of SDST, it has been extensively used in oil-gas drilling and has become the gordian technique of directing and estimating the string structure and drilling parameters. Based on the Computer Aided Engineering (CAE), the Rotor Dynamics, the Geotechnics and the Engineering Fluid Mechanics, the SDST can rationally design the string structure and optimize the operating parameters that are fit for the predicted hole path and geologic conditions, make scientifical evaluation of mechanical parameters and the purpose of calculating its safety factor into reality. This is a pre-evaluated method of the design of directional crossing string and estimating the drill tools failures. The method had been verified through the project as the directional crossing Lan-Zheng-Chang refined oil pipeline, and the conclusion was in best agreement with field datum. Application of project has indicated that the method proposed in the article is feasible and is also a economic and practical way of the design of the string in horizontal crossing reaming and the evaluation of the failures in drill tools.

Non-dig piping in hard rock stratum is a popular research topic in the world, and the bottleneck of the technology is how to control DTH hammer's drilling trace without hammer jamming. Based on DTH hammer's rock stratum drilling principle and study of modern orientation technologies in the world, this paper presents a novel Oscillating Orientation Device (OOD) applied on DTH Hammer which can control DTH drilling direction and avoid hammer jamming. The oscillating orientation device locates between drilling rod and DTH hammer which has unbalanced or incline drill head. DTH hammer and oscillating orientation device are both connected to the same compressed air resource. The oscillating orientation device will produce a strong small angle oscillation movement when compressed air is input. During straight hole drilling process, because drilling rod goes straight down without rotation, the orientation device attached to the rod will produce a straight line oscillating movement. This movement will make the DTH hammer that attached to the orientation device doing the same straight line oscillating movement too. The DTH hammer's straight line small angle oscillating movement will keep drilling hole straight and also resolve the jamming problem that normally presents in rock stratum drilling. Compared with traditional DTH hammer structure, the presented design only adds an extra oscillating orientation device and applies unbalance or inclined drill head without any inside structure change of DTH hammer. So the presented design dramatically reduces rock stratum drilling cost by avoiding jamming problems without any loss of the advantages of traditional DTH hammer like stability, long service life etc. In the paper, oscillating orientation device structure and theoretical working principle analysis based on the structure are presented. The oscillating orientation device working principle is: inside a sealed chamber, through controlling of intake and exhaust ports, high pressure air drives two symmetrical blades oscillating in a small circular sector area. Then, this movement creates the same movement of DTH hammer. According to experiment results, this novel oscillating orientation device is an economic and simple solution for resolving jamming problem of non-dig rock stratum drilling.

In drilling operation, to determine the safe mud weight window rationally is very important for borehole stability. Conventional safe mud weight window is based on fracture pressure and caving pressure. However, drilling practice experience has shown, although the mud weight meets the standard of SMWW, there are some borehole problem such as lost circulation and cave-in in the process of tripping because of swabbing and surging. Compared with the vertical well, the soakage time of drilling fluid in horizontal well is longer, the lost circulation and cave-in are more likely to happen. Therefore, SMWW of horizontal well should be calculated more precisely. This paper starts with an analysis of mud rheological property, combined with flow rate equations of different operating conditions, through math deduction for fluctuation pressure distribution model; a method of corrected SMWW calculating was established.

The choice of three-winged auger bit which completes with auger rod is important key in soft coal bed drilling. With the structure design philosophy of three-winged auger bit, Theoretical strength checking and three-dimensional design were carried out to bit. With ANSYS software finite-element analysis was did on bit. The stress distribution of the bit was obtained, which provides theoretical basis for further optimization design and improvement for three-winged auger bit.

Part of natural gas pipeline network project of Changde Huayou Gas Co., Ltd needed to cross the Zhantian Lake about 216m, and the pipe diameter was 200mm, the pipe material was PE. The strata which the pipeline crossed was artificial fill, silt, silty clay, mucky silty clay, round gravel layer in order. After comparing the several programs, trenchless guided drilling was selected for installing the section of the pipeline. For the long lake crossing distance and the complicated strata, No-Dig rig KSD∼25 with a large drag force was chosen to carry out the pilot bore construction, and then the pilot bore was enlarged through four times reaming pass until the drilled hole diameter was 500mm, Finally, pipe laying and grouting were done. The application of trenchless guided technology in the engineering was the focus of this paper, for example, the pilot bore trajectory design, pullback reaming, pipe laying process design, construction technology and control. Meanwhile, some technical difficulties such as measurement while drilling, drilling fluid preventing hole wall from collapse were studied and discussed. After field testing of the actual construction of the project, the precision of pipe laying meeted the requirements, no-dig construction process was smooth, and then the project was successfully completed within the stipulated construction period and with less construction cost.

Waikiki Public Bath Force Main Replacement Project consists of 975m of 400mm force main that carries the wastewater from the Public Bath Pump Station to a gravity sewer on the Ala Wai Blvd. This force main transports wastewater underneath Kalakaua Ave upon which some of the most expensive real state in the world are located. This area is the heart of famous Waikiki beach and it is full of beautiful beaches, resorts, five star hotels, shopping, etc. The soil strata in this area can be briefly described as 2.50 to 3.00m deep of beach sand on top of half a meter to one meter of very hard coral ledge on top of very soft layer of silty sand. The N value in this silty sand layer ranges from zero to 8. The original design of the force main was in the beach sand layer, but an old buried wooden bridge was discovered during the preparation for construction that mandated lowering the elevation to be through and underneath the ledge layer. The specified construction method for this project was microtunneling of 650 mm Permalok steel pipe with a 400mm PVC carrier pipe inside the steel pipe. The annular space between the two pipes was grouted with low density grout. Many problems were encountered during the construction phase of this project. This paper is a retrospective review of the project from the contractor's point of view. It covers the design and construction aspects of this project in addition to the encountered problems and the lessons learned from that project.

This paper introduces the application of photogrammetric methods in trenchless engineering applications including construction jobsite monitoring and three-dimensional underground utility mapping. Accurate three-dimensional representations of buildings, roads, and other utilities on the jobsite can be easily obtained through the processing of digital photographs using photogrammetric software. This provides an avenue for assisting contractors in quality control of their construction processes. The existence of telecommunication, electrical, cable, water, wastewater, and gas pipelines provide potential strike hazards for trenchless methods such as horizontal directional drilling. Subsequently, it is imperative that accurate as-built maps be generated. This paper demonstrates the use of digital photogrammetric methods through field trail of mapping and monitoring applications.

Horizontal Directional Drilling (HDD) is widely used now in many engineering fields such as pipelines installation. The horizontal directional drilling project always carries out beneath the ground, so the operators can not real-time see the process of project. Therefore, it is need to train considerable amount of operators and improve their operating experiences to make sure the project can be completed successfully. The studies we had performed provide a kind of low-cost, safe, and efficient software part of a Virtual Reality Training System for HDD in past several years. The software part mainly is the human-machine interface developed by Visual Basic 6.0. This paper studies the hardware part including the control levers, button switches, knobs, keyboard, LCD panel, PCB, and operating box. The operators will carry out various movements of the virtual HDD by operating the actual levers, button switches, knobs, and keyboard.

Rapid economic growth in China has lead to the increase in the installation of underground utility infrastructure across the country. Major international events including the 2008 Olympic Games in Beijing and the 2010 World Expo in Shanghai have spearheaded this growth. As a result, trenchless technology has seen an increase in application due to its minimal impact on the environment, increased productivity, cost effectiveness, and worker safety. For example, there are currently over 5,200 horizontal directional drill rigs in operation from approximately 30 Chinese manufacturers. This paper presents the results of a survey questionnaire distributed to 58 professionals in the underground utility including contractors, designers, manufacturers, agencies, and research institutions. Information on trenchless construction methods utilized, pipe materials, industry sector involvement, origin of equipment, and method for detecting existing underground utilities was solicited. Additionally, influence factors inherent to trenchless construction were quantified based on practitioner sector. Existing utilities and experience of personnel were found to be the most critical factors when assessing an underground utility infrastructure project. These were closely followed by equipment capacity and soil features. Understanding the perception of practitioners should lead to more success underground utility infrastructure projects in China.

For the collapse of the sand and gravel stratum in the process of trenchless drilling hole , based on elasticity analysis with the elasticity theory of horizontal directional drilling hole wall, the stress states under different lateral pressure coefficients are analyzed after reinforcing the sand and gravel stratum which is prone to collapse. Meanwhile, the reinforcement requirements for maintaining the stability of the hole wall under different conditions are put forward. This study can supply the reference for the project of reinforcing the horizontal hole.