ICPTT 2009: Advances and Experiences with Pipelines and Trenchless Technology for Water, Sewer, Gas, and Oil Applications

This paper presents a web-based application tool called Analytical System for Planning of Infrastructure REhabilitation (ASPIRE) to help public agencies plan efficient rehabilitation strategies within limited budgets. They can make final decisions on infrastructure rehabilitation by estimating the physical conditions of facilities and allocating limited budget based on the evaluation score in the presented application. The ASPIRE gets input from five different participants who have their own roles: 1) a supervisor; 2) a Primary Decision Maker (PDM); 3) Group Members (GMs); 4) a Field Engineer (FE); and 5) a Cost Estimator (ES). The ASPIRE also provides a flexible evaluation database according to the type of infrastructure based on technical and social/political criteria and sub-criteria levels. The group evaluation module in the model provides a more objective evaluation score of infrastructure systems. This paper describes the web-based application and illustrates the results of a case study to explain the model and its application.

The objective of this paper is to develop Risk analytic model that ranks risk priority of potential risk events in underground pipeline system. Risk priority, corresponding with the actual condition in the pipeline system, helps asset manager to target and refine maintenance plans, capital expenditure plans, investigative activities, and deal with potential failure before it occurs. The risk analytic model predicts the failure probability level and the failure consequence and then prioritizes the failure risk. Linear model and "max" average method were called separately to evaluate the risk occurrence probability based on the available data of pipeline system and rate the risk consequence scale, while Ordinal risk matrix was developed to rank the risk priority by combining the risk probability level and consequence level.

This paper focuses on developing a rapid and cost effective evaluation methodology for the condition assessment of culverts to estimate their remaining service life. Nondestructive inspection methods are selected based on their reliability and effectiveness. A synthesis of current and emerging non-destructive technologies (NDT) for culverts assessment management is presented. The information presented intends to serve as a database for a generalized algorithm for selecting a NDT scheme for condition assessment of culverts and their embedment.

Important protection tool for new oil and gas pipeline system security and reliability is integrity management which including information gathering and collating, reliability assessment, pipeline safety inspection and assessment, risk forecast. Pipeline integrity management System can promptly and intuitive, vividly assesses factors which affecting pipeline safety, at the same time a major potential cause of an accident and major source of risk monitoring as well as to provide relief after the incidents. Management system with a strong software, which can not only provide emergency rescue assisted decision system for pipeline operation, risk assessment, risk mitigation, evaluation of residual strength, evaluation of residual life, emergency incidents and natural disasters, but also provide virtual platform for the pipeline design and planning(Peng & Zhang, 2006). This paper discusses key technologies of establishment pipeline integrity management platform, such as oval design, database design and network design, and through the Lanzhou-Chengdu-Chongqing product oil pipeline, pipeline integrity management system model is designed and developed(Zhang et al., 2006).

Corrosion is recognized as one of the most important degradation mechanisms that affect integrity of metallic buried pipeline. The remaining life prediction of pipeline is to forecast the thinning trend of wall thickness, and forecast remaining life on the premise that remaining strength of pipeline meets the pipeline operation and safety requirements. This paper introduced the prediction method of the most probable maximum corrosion depth of the entire pipeline: the maximum corrosion depths in each of sampling pipeline section were taken out to form a group of sequences, and calculated the corresponding cumulative probability; Statistical parameters of Gumbel distribution function were calculated by the Least-Squares method; Based on the maximum extreme value distribution and return period, the calculation formula of the most probable maximum corrosion depth of entire pipeline that was estimated by corrosion data of a small number of sampling pipeline sections was obtained by formula derivation. The calculation formula of maximum depth of corrosion defect was derived by the method of DNV allowable stress. For the pipeline with one inspection, the relation between remaining wall thickness and time was established, and the calculation formula of remaining life prediction of pipeline was derived based on it. In this paper, remaining life of a domestic pipeline was predicted and analyzed by the method of extreme value distribution. By comparison of linear model and exponential, the calculation result of linear model is more conservative than that of exponential model.

Total integrity of an oil pipeline in China is assessed in four aspects: 1) risk assessment based on scoring system, 2) corrosion protection system evaluation including soil, coating and cathodic protection (CP), 3) remaining strength evaluation of corrosion defects and 4) geological environment evaluation along pipeline. Results show that the risk of pipeline is at low level on the whole except four segments with high risk due to river crossing, shallow buried depth and high population distribution. More than 99 percent of epoxy powder coating of the pipeline is in good quality according to evaluation results from 1,437 inspection records of Pearson Survey and Pipeline Current Mapper (PCM). Likewise, evaluation of on/off potential in volts in past half year shows that the protective rate of CP is more than 97 percent. PIM plan and counter-measurement are formulated to ensure pipeline safety especially to segments with high risk or poor-quality coating.

Large diameter water transmission mains represent a significant portion of the underground assets of any given water utility. Until recently, there have been few options available for ascertaining the actual condition of these assets. One notable exception has been Prestressed Concrete Cylinder Pipe (PCCP). Since the invention of RFTC technology, developed at Queen's University in Kingston, Ontario, Canada in the early 1990's, more than 4,000km of PCCP has been assessed. This condition based asset management technique has become the standard for those utilities who want to establish a long term maintenance and management plan for their PCCP networks. With the introduction of the Sahara leak detection system, the industry now has a powerful tool to gather direct information about the condition of any transmission main — regardless of its material construction type. The Sahara system accurately pinpoints the location and size of leaks as small as 1 liter/hour. A utility can utilize this system to precisely locate leaks, reduce non-revenue water, identify leaks causing pipeline commissioning delays, and as a condition assessment / risk management / asset validation tool that provides information that forms the basis of future asset management strategies.

A dynamic test is presented on the GU-YONG-DONG (GYD) pipeline through the lower Yellow River, which is an oil transported pipeline of Shengli oil-filed in Northeast China, to get the dynamic parameters of the suspended pipeline. An urgent treatment by fixing inclined steel cable is adapted according to the characteristic of the suspended pipeline force and deformation. The static force and vibration parameters of suspended pipeline are studied after/before the urgent treatment and it is evaluated by comparison. The results indicate that the Max von Mises stress of suspended pipeline decreases with the tense load of steel cable, the tense load of per cable is recommended to be 20kN considering local strength. The inclined cable has little effect on reducing the displacement and natural frequency of suspended pipeline for its small linear rigidity. The concrete anchor block should be used to enhance the suspended pipeline to avoid sympathetic vibration. The average fatigue injury degree of sixty days is 8.94% and it seriously affects the fatigue life of the pipeline.

Based on the establishment of energy balance model, energy loss rate and unit energy loss are proposed to evaluate the energy loss of pipelines, heat energy loss rate and pressure energy loss rate are used to analyze deeply the structure composition of pipeline. Thus the reasonable judgment about the situation of energy utilization for pipeline can be made and its transferring capability can be reflected actually. The energy loss evaluation and analysis calculation is done with the pipelines network of some oil and gas gathering and transferring system in Daqing oilfield. The results show that the average energy loss rate of the pipeline system is 11.81% and the average unit loss is 0.73 x 10⁵kJ/t⋅km, which has a certain energy conservation potential. Heat energy loss accounts for 96.24% and pressure energy loss 3.76% in the constitution of energy loss, which indicates that energy conservation should focus on how to save gas. In accordance with the actual operation situation of pipelines, this paper put forward a series of technical renovation measures for energy conservation, through which the annual energy conservation quantity can be estimated to be up to 5.58 x 10⁶MJ, that amounts to the energy of 1.30 x 10⁵m³ natural gas.

Research status on domestic and overseas for hyperbaric dry welding maintenance techniques and equipments of subsea pipeline are reviewed in this paper, with emphasis on underwater dry pipeline maintenance system, which is composed of underwater dry hyperbaric cabin, dry hyperbaric welding, plug and other auxiliary machines and tools, the author and his research group develop this system during the Tenth Five-Year Plan Period, and it bring to success in the test of 60 meters deep subsea pipeline hyperbaric welding.

Scour around a river crossing pipeline creates a free span of pipeline and leads to excessive flexural and deformation stresses. Generally, generated stresses on pipelines under high internal pressure are dominated by circumferential stress. Longitudinal stress, however, is a main contributor in the procedure of stress development because a free-span pipeline exhibits unstable behavior as a simple supported beam and results in bending stress. For this study, a specific section of river crossing pipeline was defined as follows: API 5L Gr. X65, Do=762mm (30-inch). Based on a plastic design concept, the interface stress for the steel-concrete composite pipeline and its performance under specific flow velocity were defined using results from FEM analysis. In order to describe the loading condition of the exposed encased pipelines, Prandtl-von Karman universal velocity law is adopted with rough river bed surface, fixed water depth and variable scouring depth. In the general condition of a river, although 20m free-span pipelines have been developed, encased pipelines perform well according to the von-Mises failure criterion.

With the rapid development of digitalization of water supply industry and the implement of computer control, it is necessary to test roughness coefficient of water pipes in the distribution system. Theory of testing roughness coefficient of water pipes and principle of choosing the testing pipes and the working condition of these methods was introduced. Traditional testing method was improved, and by analyzing these methods, a testing method which was fit for the testing of water pipes in water distribution network of China was presented.

The casing failure is serious in Zhongyuan oil field, This case happened frequently in the salt formation of the Tertiary shahejie group. And the casing deformation is the main form of failure. Research reveal that the main cause of casing failure is that the external load acting on casing due to salt formation creep under the nonhomogeneous in-situ stresses exceeding the collapsing strength of the casing. The key to avoid casing failure is the proper casing grade. The salt formation is regarded as Maxwell model, and a viscous elastic mechanical model for plane strain features is established. based on the experimental results of triaxial multilevel loadings for the salt rock creep, the creep constitutive model and creep parameters is given, Combined with geologic condition of the Tertiary salt formation in Zhongyuan Oilfield, with the analysis and calculation of the external load acted on casing due to salt formation creep under the nonhomogeneous in-situ stresses by finite element method, the variation laws of the external load are achieved. The relationship of the external load and the collapsing is close. Establish the predicting model of casing service life. Considering the affect of corrosion, estimated the casing service life in salt formation and get the exact result which can guide the casing string design in this oil field.

This paper discusses the problem of pipeline plugging by gas hydrates during oil production. Gas hydrates are generated from water and gas molecules association under high pressure and low temperature conditions, like the areas in deep offshore fields or in cold areas. An understanding of the blockage potential for an oil dominated system is an important step in moving from hydrate prevention to hydrate management. As production moves towards increasing water depths, the challenges of the security have been changed, the flow assurance strategies are shifting from total hydrate prevention to hydrate flow management, allowing hydrates to form but guaranteeing their transportability as slurry. The feasibility of such strategies and the risk associated with hydrate transport must be established in order to gain confidence in a safe operating envelope. Introduce a new concept about Hydraflow technology. The idea is to convert most or all of the gas phase into hydrates and transfer them in the form of hydrate slurry in the pipeline. Where produced water is limiting factor for hydrate formation, excess water (e.g. seawater) can be added. It is also possible to adjust the hydrate slurries viscosity by adjusting the amount of water. Anti-agglomerants and other additives might be necessary to control the hydrate crystal size and prevent solid blockage in these systems. Then describe the development of a first generation empirical tool for the prediction of hydrate blockages (CSMHyK-OLGA) in flow lines. The study indicates that these specific strategies must be developed carefully in oil production fields.

Aiming at oil pipeline, we designed a suit of oil pipeline leakage detection and location system, which based on negative pressure wave method technique. There are tow key techniques to realize oil pipeline leakage detection and location, which include how to ensure the speed of negative pressure wave, and how to ensure the time that the negative pressure wave arrive the both ends of pipeline. We put forward the relevant resolve method, and let the wavelet transform and GPS technique into it, the practice indicate that the capability of this system is steady and reliable, and the precision of leakage location is less than 1% of the length of pipeline.

Monitoring of ship pipeline leakage detecting is one of the most important techniques to be developed as it can help to prevent damages of ship working safe. In this paper, wavelet transform is used as a tool, to characterize the real time pipeline flow signal during ship working. Firstly, we use the Mallat algorithms to get the standard wavelet transform result from the pipeline flow signal. During the detection period, we get the real time wavelet transform result on certain level through the real time wavelet algorithms. The real time wavelet results of both sides were examined by the correlation to its normal result. According to the magnitude of the correlation factors, we can make sure whether the normally. The results of simulation show that the selected monitoring indices from the wavelet coefficients are capable of detecting in the ship pipeline leakage effectively.

Globally, water demand is rising and resources are diminishing. Most of the world's water systems have been highly successful in delivering high-quality water to large populations. However, most of these systems also incur a notable amount of loss in their operations. Water loss from the water supply system has long been a feature of operations management, even in the countries with a well-developed infrastructure and good operating practices. There is no doubt that the sustainable management of water supply system is a challenge for the whole world. Water leakage cannot be completely avoided, but they can be managed so that they remain within economic limits. Some new models of water loss management have been developed recently. As the technical and economic levels varied in different cities, the best practice using in their water supply systems leakage control should be taken suited to local conditions. In this case study a water loss management strategy for a large city in north China was suggested and the technological means for the optimized its managing were provided. The basic principles for structuring district meter areas in this water supply system according its features were developed. The GIS as the tool was used during the study. Based on the field test, the water balance calculations of three DMAs were carried out, and using the fuzzy appraisal method to evaluated their degree of water losses.

The effectiveness of airborne laser detection equipment on buried pipeline small leakage is firstly validated by experiment. Dispersion range of pipeline small leakage is simulated by software and verified by experiment. The methane clouds produced by artificial leakage sources, which are placed at plane and hill terrain, are detected by the equipment on helicopter. The flight height varies between 60 and 150 meter at plane area. Five artificial leakage sources are placed along the West-East Pipeline at hill terrain where flight height varies between 60 and 500 meter. Experiment result shows that airborne detection method is suitable for plane, desert area but unfit for area that has large altitude diversification. The result can be a reference for the long distance transporting pipeline safety management.

Water is now considered as an essential resource, which should be managed in an integrated manner. Monitoring of water pipeline is an important task for economical and safe operation, loss prevention and environmental protection due to leak. A leak detection of water pipeline, therefore, plays a key role in the overall integrity monitoring for a pipeline system. Especially for buried water distribution pipes and near to sewage pipes. In this paper, a leak detection and location approach based on transient pressure using cepstrum method in a parallel pipeline is proposed. The technique involves the injection of a pressure wave into the pipeline under investigation and the time domain signals of these pressure transients were obtained using a single pressure transducer. This information first filtered using wavelet in order to remove DC offset and then analysis using cepstrum method. Due to their simplicity and robustness, transient analyses provide a plausible route towards leak detection and gives information about the all features distributed in the pipeline.

When leakage occur during pipeline pressure testing, the intensity of leakage will attenuate continuously, which was assumed as a constant, so that the location accuracy was not good. To calculate the leakage location and attenuation coefficient of pipeline under pressure testing, the inverse problem of pipeline leakage was studied using numerical inversion technology based on model building of the direct problem of pipeline leakage. Then the existence and uniqueness of the location and attenuation coefficient of leakages were proved with principle of contraction mapping, and their solution methods were obtained. Finally the numerical simulation analysis showed that the methods were feasible and easy to use with high accuracy in theory.

The buried pipeline leakage often causes safety accidents. It is particularly important for rapid rush repair preventing the leakage diffusion to judge the leakage point position in time. Using infrared remote sensing equipment to quickly detect ground, the leakage point can be judged. Considering the buried pipeline as the research object, this paper shoots the variation characteristics of ground temperature field in pipeline leakage process by infrared thermographs instrument, puts forward the method that based on the temperature measurement principle of infrared radiation to detect pipeline leakage. The CFD software was used to simulate the temperature field of pipeline leakage, and built the pipeline leakage infrared imaging experiment. The results show that the temperature field can be separated into 3 regions after the pipeline leakage. The fist region is constant high temperature region, in which the water temperature will remain basically, the second is temperature gradient region, the temperature changes violently, and the third is soil natural temperature region, the temperature changes smaller.

Summarize the main distribution of the oil pipeline of Yan Chang Oil in Maowusu desert, up oil pipeline leaking fault tree, through carrying on the qualitative analysis to its 48 elementary event's structure importance, obtain this leaking fault tree system's 11 most trail, out that this leaking accident's main factor is the pipeline leaking other factors (A₁) and the project safe mass factor (A₂), the latter for the most important attribute. Begin with 48 kinds of basic elements, take effective measures to prevent, control leaking fault tree of oil pipeline in Maowusu Desert and reduce the huge economic losses and environmental pollution.

The Simulation and Management System on water distribution networks (SMS) is developed to detect pipe bursts in real-time. It is designed by modular programming and is divided into three subsystems of network design, real-time control and data management. The implementation of bursts detection is based on burst characteristic values and similarity analysis. Firstly, the ideal burst characteristic values are calculated based on leakage rate. Then the real value is computed after state estimation. By using the fuzzy similarity ratio of ideal and real values, SMS can find out whether there is a pipe burst in the network. If there is, it will issue warnings. Through the application on an urban water distribution network, which was composed of 55 nodes, 94 pipes and 40 loops, it was proved that SMS was reliable and its detection accuracy was higher than 80%. Therefore, SMS is useful in real-time control of water distribution networks.

Large diameter and high pressure is the typical feature of long distance gas transmission pipelines. Pipelines are subjected to corrosion, cracks and other kinds of deformations. Ensuring pipeline integrity and the associated utilization of in-line inspection (ILI) tools have become primary concern of pipeline operators. A novel nondestructive technology named intense magnetic memory (IMM) was introduced to pipeline inspection. Excited by geomagnetic field and intense residual magnetic on workpiece, microdefects can be found only by detecting self-magnetic leakage field (SMLF) in the pipe wall. It is especially suitable for assess damage condition of integral work pieces by indicating the position and severity of stress concentration region, which is the origin of various defects. A special IMM ILI tool was designed for Φ529 gas pipe. Laboratory testing pipeline system was setup and artificial defect was inspected. Signals were processed and characteristic feature was extracted to obtain detail defect information. Initial experimental results show that it is promising for IMM technology being applied to pipeline inspection.

The galvanostatic transient response method was used to detect the underground pipeline coating on the spot without excavation. With wavelet and neural network method a multi-layer model was established to analysis the detection information. The model was made up based on Self-organization of Kohonen neural networks and the advantage of wavelet to pike up the useful information. The model has three parts, the front five layers have the ability to pike up the information, the weights of this part are the adaptive wavelet coefficient (filter). The sixth layer corresponding to reconstruction of wavelet analysis, in this way some useful information can be resumed. The last layer has the ability of self-training. After self-training the weights were remembered like BP neural network. It is confirmed that the method is correct and convenient for on-the-spot detection by the detection result of actual pipeline between Dezhou and Puyang of Zhongyuan Oil Field.

Since most urban gas pipelines are buried under the ground, there are more demands for using trenchless technology in pipe inspection. Employing intelligent in-pipe robots, which can carry NDT devices and tools into pipelines to complete inspection and maintenance, appears to be one of the most attractive solutions now. While travelling into urban gas pipelines, there is no light source in dark pipelines, and inspection robot should carry the illumination instruments providing brightness. As the gas pipeline is a structured and constrained space, the images taken from robot vision system often cover advanced knowledge about environment structure and useful information of events in scene, which can be used for autonomous navigation of in-pipe robot. On the basis of analysis of the model of optics and the property of imaging process, the image of inner pipe wall can be divided into three different regions corresponding to bright region, gray region, and dark region. According to the change obtained from three regions in the image, the new methods of recognition for straight pipe, elbow pipe, `T' shaped branch, and blocks were developed. Then, combining these recognition methods, a navigation strategy with monocular vision system was presented for the robot autonomously navigating in gas pipeline. The simulation experiments show that the presented methods are available for recognition of straight pipe, elbow pipe, `T' shaped branch, and blocks in gas pipeline environment. This has benefits for improving the intelligence and automation of gas inspection robot.

With the development of the oil field, Casing damage become more and more serious. Severe casing damage well causes not only the well's production suspend, but also affects adjacent wells, even the normal development of oil field development block, making a serious impact to the oil field's production, becoming constraints to Oilfield development. The significant problems will hinder the stability of the oil fields. Magnetic pulse detection is one of the effective methods that can examine oil and gas wells' states. The time cutting the signal can detect the construction of the annulus multi-string. The detection is achieved through selecting the magnetic pulse and intermission width, with the target's information recorded during the intermission time. The Iterative regular method can limit search area and consider the characteristic of the pipe. It can work in the wells that are individual layer, two-layer or multilayer, filled with different media (gas, oil, water and drilling fluid etc) without the wells closed. The physic and math bases of the method needs further exact research. The applied example would give the determination technology about the pipe well thickness.

This paper presents the current internal defects positioning technology of pipeline, and deeply analyzes the characteristics of the main positioning methods, error causing mechanism and accumulative characteristics, and proposes a new combined positioning procedure, which applies INS (inertial navigation system) assisted by ground markers /weld /odometer to achieve the exact position of internal defects of oil and gas pipeline. INS is the core of positioning as a non-contact measurement. Its positioning manner is not affected by the internal environment of the pipeline and the error production and accumulation characteristics can be estimated; applying ground markers and weld signal, INS errors could be limited at a small range. This paper also develops a mathematical model of INS, establishes the INS/odometer navigation algorithms in accordance with positioning characteristics of the pipeline internal defects, and makes quantitative analysis on the algorithm errors of INS and the combination, which makes a useful exploration so as to reduce positioning errors and develops high accuracy of the positioning scheme.

During the building and running of the long distance natural gas pipeline, pigging operation is a very important process to ensure normal work and gas transport efficiency. There are three kinds of pigs: spherical pig, mechanical pig and the pig used for pipeline inspection. This paper introduces the main construction and work principle of the spherical pig and mechanical pig used commonly, studies the comparison and selection for the scope of application and working indication, and makes a mechanical analysis for the operation action of the pig in pipelines. Combined with site experience of the pigging work in west-east gas transport project, this paper discusses the common troubles and handling ways in the pigging technology and process, and explains the evaluation indicators of pigging effect. There is an important reference value for the pigging of other pipeline projects.

Oil gas submarine pipeline generally needs to pass through different shallow sea shelf areas, therefore, may encounter various unstable geological problems unavoidably, such as tidal bank and tidal creek migration, slope soil body slumping and taphrogeny, submarine differential erosion and sand wave migration etc., which lead to suspended span, damage and even breaking-down of pipeline. Based on pipeline route survey and post-lay detection data of oil gas submarine pipeline in shallow sea shelf area, this paper studies the distribution rules, genetic mechanics and hazard to submarine pipeline of the following unstable geological factors, including the migration of tidal creeks and tidal banks in Liaohe River delta, submarine differential erosion in Huanghe River delta and the relict sediment area of continental shelf of northern South China Sea, sand wave activities in the continental shelf of northern South China Sea and the submarine slope soil body slumping in Huanghe River delta etc. Survey data reveal that the maximum migration rate of tidal creeks and tidal banks in Liaohe River delta may reach one hundred meters and the differential height between them is 2m to 5m. The height of submarine differential erosion in abandoned Huanghe River delta varies between 4m and 6m. Slumping and taphrogeny of submarine soil form large amount of disturbed soil strata, slope and silt flow sediment. Differential erosion in the relict sediment area of continental shelf of northern South China Sea may lead to the formation of furrows and ridges with the differential height of above 30m. The height difference between moving sand wave peak and wave hollow may reach 8m. Moving sand waves, which are 3.5m high, may come into being in the shelf seafloor, where the water depth is more than 100m. The study concludes that tidal current and estuary runoff control the migration of tidal creeks and tidal banks in Liaohe River delta, whose moving rate is in positive correlation with tide range and current velocity. Differential erosion, slumping, taphrogeny, landslide in abandoned Huanghe River delta are closely related to sediment types and characteristics, topography, shallow stratum structure, regional scour-and-fill background and hydrodynamic force. Furrows and ridges with the height difference of more than 30m caused by differential erosion in the relict sediment area of continental shelf of northern South China Sea are controlled by stratum structure, hydrodynamic force etc. Sand wave movement in shelf seafloor is mainly affected by typhoon. The submarine pipeline passing through the unstable geological area faces the risks of exposure, suspended span and even breaking-down, therefore, the site selection of pipeline route should try to avoid the unstable areas and increase the burial depth or take appropriate prevention measures when necessary.

As an important measure of evaluating the completing pipelines, the exact description has been adopted in almost horizontal competing pipelines with a quantificational and visual point. The principles of detector for almost horizontal competing pipelines, encapsulation of hardware, disposal of software and creative application all have been discussed in the paper. The limit application of the small diameter has been broken through; the model method of conformity of three-dimensional for curve has been built; and continuous dynamic inspection for three-dimensional coordinates, the accuracy of static azimuth is ±1°, the accuracy of obliquity is ±0.5, the error of the distance between the two points is ±20cm, the vacancy of the concentric products has been filled up because of the application of this detector.

The space trajectory of laying flexible pipes should not only depend on the process parameters in HDD technology. This detection method is introduced to trace three-dimensional space trajectory of non-metallic flexible pipes. Based on this method, a trajectory measuring instrument is invented by using high-precision Honeywell digital compass to measure the pitch and azimuth angles, and then to set up a mathematical model with the minimum radius of curvature method. The actual space trajactory of pipes can be reconstructed accurately, and the three-dimensional trajactory can be visualized when the device is connected to computer terminals. The instrument is proved reliable in the worksite.

The chief composition of methane is marsh gas in coal mine, which is a prime energy. So, it is important that methane drainage is used effective. The optimal design of pipeline system for the methane drainage is a problem which involves many fuzzy and uncertain factors. Applying Matlab function to build an optimal design and select proper training samples, the method based on combining the fuzzy theory with artificial neural networks is used to design the pipeline system. The fuzzy neural network is also an information processing system combining the artificial neural network and the fuzzy theory, which can reduce size of the fuzzy neural network and improve learning speed and reliability of algorithm. The example of Dongyu Coal Mine shows that fuzzy neural network superior design based on Matlab can more effectively avert disadvantage of the common network.

A branch system of optimizing operation of sulige gas field pipeline network is developed by comprehensively adopting the advanced computer network technology, database technology, pipeline network simulation and optimizing scheduling methods. The information of technological process, production performance and operations management in the gas gathering and transportation is integrated effectively. Thus the web-based sharing, searching and maintenance of pipeline information are completed in the form of visual graph and interactive mode. The data collection is automatic and the operating scheme is automatically formed. Moreover, the system structure framework, database design, function modules and applied characteristics are introduced and this optimizing operating system of pipeline network has been integrated into to the digital system of sulige gas field production and management with good validity.

Based on Biot's dynamic theory and the complex variable function, a new method is used to solve the dynamic response of a pipeline in half-space porous medium to incident harmonic plane body waves. Here, a circular arc with large radius is applied to simulate the half-plane boundary. By using the theory of Helmholtz, The equations of the steady-state Biot wave motion are decoupled to Helmholtz equations by introducing in the potential functions. The general solution of Helmholtz equations is given by means of the complex series expansion technology. Utilizing the general solution of the potential functions, the expressions of the displacements, stresses and pore pressures of porous medium and those of the displacements and stresses at the pipeline can be obtained with certain boundary conditions of this problem. Then the variations of the coefficients of dynamic stress concentration and the pore water pressures concentration at boundaries of the pipeline structure are discussed with different parameter conditions. The results of the given numerical example indicate that the thickness and the shear module of the pipeline have great influence on the dynamic stress and strain of the pipeline. The proposed methodology in this paper may provide a new method for the analysis and design of underground pipelines accounting for transverse forces.

This paper describes the research carried out by the Buried Asset Management Institute International, Inc (BAMI-I), which was sponsored by the Environmental Protection Administration (EPA) under EPA Grant-CP 83 282901-1. This project involved the cooperative effort of a unique team of academic research leaders of four major universities, utility representatives, and several professional associations. A survey developed for one of the participating universities showed that the majority of utilities claimed to have some kind of asset management program. The majority considered that creation of a National Center of Excellence would provide the biggest benefit through training for manager, engineers and for personnel. Therefore, the existing need for knowledge, training and education about asset management practices in the water industry motivated the creation of this certification program. Based on the individual projects of each consultant, BAMI-I created the Asset Management Training Certification Program. The Certification Program is an online educational process for obtaining certification of training in management of underground asset infrastructure. It is a pioneer program in the United States that is establishing a new path for stakeholders in the water industry interested in achieving water utility infrastructure management excellence.

The oil-gas gathering and transportation system refers to the complicated fluid network system composed of pipes and stations, the optimization design of which will lead to obvious economic benefit. For the oil gathering process with double-pipe mixed with water commonly used in the oilfields, the mathematical model for the multi-objective parameters optimization design of oil-gas gathering and transportation pipe network is established, wherein the diameters of oil gathering pipelines and water mixing pipelines, the water mixing amount at wellhead and the outlet temperature of hot water are taken as the design variables, and the minimal pipe network investment, the lowest power consumption and the lowest heat consumption taken as the objective functions. This model belongs to the large-scale mixed variables multi-objective optimization design problem, with the objectives conflicting with one another. According to structural characteristics of the problem and the intents of decision makers, the evaluation function method is adopted to convert this problem into the single-objective optimization problem, and then it is solved through the hybrid genetic algorithm. The corresponding computer program is worked out and the calculation example is given in this paper. The calculation result verifies the effectiveness and reliability of this method.

For increasing the accuracy of estimate, numerically calculate the temperature field of soil around pipeline should consider multiple factors influence, such as climatic change, the depth of the buried pipeline, moisture transfer, ice-water phase change etc. The temperature field of soil around underground pipeline in the process of cool and hot crude oil alternately transportation is numerically simulated through using finite elements method. The effect of moisture transfer and phase change on temperature was taken into consideration. The temperature distributions of soil around pipeline and oil within pipeline at different time are obtained. The contrast analysis the calculation results between using water and heat couple model and using heat transfer model, show that the heat retention in soil have great effect on oil within pipeline and the moisture transfer and phase change have definite effect on heat transfer of the soil. In order to get approach actual results, they should be considered in calculation.

For drawing up science and reasonable crude oil transportation craft, we should accurately forecast the change of soil temperature field around pipeline and oil temperature within pipeline. The soil temperature fields around the buried hot oil pipeline during starting and oil temperature within pipeline are numerically simulated through using finite elements method, find out how the soil temperature around pipeline distribute and oil temperature within pipeline change at different time. Analysis the calculation results show that the time of infusing oil after preheating should be in line with the requirement, and multiple factors obviously influence oil temperature change within pipeline, such as staring time, staring temperature etc. The reliable basis is provided for hot oil pipeline to operate economically and securely.

The discussed system is composed of a multiproduct pipeline connected to several depots and the corresponding consumer markets that receive large amounts of product oil. A mixed integer non-linear programming (MINLP) optimization model is proposed for the scheduling system. The model must satisfy all the operational constraints, such as mass balances, distribution constraints and product demands. Algorithms based on the hybrid genetic algorithm (HGA) are employed to solve this problem. The basic structure, coding manners, decoding rules, fitness function selection, mutation and crossover operator and the judging flow of chromosome feasibility of the algorithm are explicated. Scheduling result from the Lanzhou -Chengdu -Chongqing product pipeline shows the efficiency of the algorithm.

In the case of buried utilities, the quality and reliability of asset related data which is the basis of intervention decision making, is often questionable. This paper presents a stochastic study using Monte Carlo simulation, aimed to investigate the operational condition of a network of sewer pipelines, under different ranges of values of a set of operational parameters. These parameters included: pipe age, length, diameter, slope and Manning's roughness co-efficient, whereas operational condition grade is the response variable. In a parameter impact analysis, each parameter was studied separately with different probability distributions, while keeping all the other parameters at their best fits. Comparison of these simulated overall operational conditions of the network with its actual condition elicits the impact of making system wide changes in the studied parameter. The results of this study can assist infrastructure engineers in making more informed network planning and design related decisions.

The vertical arrangement of the nodes is very important in the comprehensive industrial pipelines planning, the reasonability of vertical arrangement scheme directly affects the cost and operation of entire comprehensive pipeline system. According to the characteristics of industrial comprehensive pipelines vertical arrangement in the nodes and the principle of minimum earthwork volume, a new method of nodes vertical plan is established and programmed to make it easy to achieve on the computer. In view of the model's insufficiency, a qualitative adjustment method is proposed. Then this method is used in the intersection of a factory, an optimization vertical arrangement scheme is obtained to show that this method is feasible and effective.

During the process of horizontal direction drilling (HDD), there is often a problem due to the mismatching between the water (or drilling fluid) flow capability though the reamer and the pump output. Using the fluid mechanics theory, this paper deduces the matching mode of the reamer. The water way and the pump output combining the Trenchless Technology of HDD equipments and hydraulics, and the results are verified through the field test. The error is approximately 3% in the matching mode and is useful for practical engineering applications.

SPS and TGNET are the two kinds of software commonly used in Natural Gas Pipeline Network Simulation. How to choose simulation software according to the actual situation is the question deserving our discussion. Through the use of the two softwares in a multi-gas sources natural gas pipe network static and dynamic simulation, we found that: the simulation results from SPS and TGNET are very reliable. TGNET has advantage in the buildup of model and the result display and SPS has advantage in fast dynamic simulation speed and the advantage more obvious if the pipeline network is more complex. At the same time, SPS has an advantage of programming in specified language according to the actual situation to form the INTRAN file which can realize the logic control. By this way, it makes the model more conform to reality. Finally, it is suggested that TGNET is suitable for static simulating simple pipeline network and SPS is suitable for dynamic simulating complex pipeline network.

With the interface of different batches moving in products pipeline, the flow rate changes very complicated. The study shows that the flow rate varies not only with the batch sequence and the distance of interface moved through in pipeline, but also with the elevation at which interface flows in the pipeline which runs through mountain areas. It is proved in Lan-Cheng-Yu products pipeline that the flow rate may be increased, decreased or unchanged when the interface moving in slope up section of the pipeline. Whether and how the flow rate changes mainly depends upon the average elevation gradient of slope up or down section and local elevation gradient at which the interface is moving. It is very helpful for operators to know and operate the pipeline well.

Within the deeper development of oil field, some oil fields, such like Daqing, Shengli, Liaohe, are coming into the high water cut stage. At the same time, the viscosity of pipeline fluid decreases as well as the freezing temperature increases. So, the method of transferring treatment without heating treatment can be adopted during the process of flowing in the pipeline. The article focuses on the analysis of the pipeline temperature drop and the drawdown calculation in multiphase delivering processes in the high water cut stage of oil field. It obtains the drawdown calculation methods of produced pipeline and analyses drawdown affecting factors of crude oil with high water content. At the condition of high water cut, the friction resistance of pipeline has decreased, which is good for further decreasing the energy of oil gathering system and saving investment. The researches in this article are very important for the reasonable design of gas-oil gathering pipeline, effective management and the economic operation of gathering pipeline in oil field.

In offshore heavy crude oil producing, the W/O emulsion is transported by subsea pipeline to plant on the shore for further treatment. By effect of de-emulsifier, water keeps being separated from emulsion during pipelining. It leads not only water increasing gradually but also viscosity and water content of emulsion decreasing gradually as emulsion flowing along the pipeline. For hydraulic calculation of water and W/O emulsion multiphase flow with mass and viscosity variation, the flow simulation experiments are made and the segmentation calculation method is put forward. It is available for Suizhong 36-1 subsea pipeline which transports mixture of water and W/O emulsion with variation mass and viscosity. The relative errors between calculation and test results are less than 10%.

Thesis based on the improved framework of the hydraulic calculation model and the calculation method, with the utilization of the Visual Basic program accompany with the Access database, the application software applied for hydraulic calculation on the general heating network goes a certain versatile. High degree of accuracy of this software brings about the convenient utilization. During the process of the variable condition calculation, the program shall distinguishes the topological structure automatically and regulates the iteration of the incidence matrix under the circumstances of the merely modification for the varied pipeline and corresponding information of the nodes. Eventually, we took the variable condition hydraulic calculation of the multiple heat sources network as an example. Then obtained and analyzed the flow parameters of pipe network, the pipeline flow, head loss, the ratio frictional resistance and so on.

When blast furnace gas turbine suddenly stops in large iron and steel enterprises, gas supply should be emergency cut off. Large amount of gas will accumulate and the pressure fluctuation will be large in the pipeline. The pipeline equipments and other gas equipments will be damaged, if not taking corresponding measures. This research study focuses on modeling and simulation of distribution network under the typical fault condition, and it has important reference value for the design and safe operation of pipeline network. Finite Difference Method is commonly used in pipeline simulation, but for the coefficients of discrete equations have characteristics of strong correlation with unknown, results are seldom accurate by Finite Difference Method. In this paper, the compressible Fluid High-order Finite Volume Method and its series improved algorithm is used to simulate and analyze the behavior of natural gas pipeline under the typical fault condition when emergency valve of the main gas using device suddenly cut off. Adopting SIMPLEC, density parameters fixed before the updating of pressure iteration, and once again updated by larger under relaxation operator after the pressure parameters update, the method gives accurate and fast convergence numerical solutions.

Separation of gas using polymeric membranes has become an important unit operation. Mathematical modeling of this process has attracted considerable attention in the past. A differential mathematical model for hollow fiber membrane gas separator was established and used for design and check calculation of multicomponent gas separation. The influences of the characteristics of feed gas, pressure drop within the hollow fibers and concentration polarization were taken into consideration. We developed computing software for gas membrane separation with lab view. The results showed that our model could provide more accurate characterizations of mixed gas permeance of hollow fiber membranes than other estimation methods. And this software was convenience for design and check calculation of multicomponent gas separation with hollow fiber membrane module. The research results in this paper can provide the reference to laboratory test on gas membrane separation and foundation for the application of gas membrane separation technique to industrialization.

In drainage engineering design, particularly, in analysis, check and hydraulic calculation of drainage pipe network, recognition and acquisition of drainage pipe network is the first and foremost task (Li et al., 2007).To implement the auto-generation of drainage pipe network drawing, this paper applies the graph theory to model the composition and data structure of a drainage pipe network. An effective method is proposed to automatically generate the directed drainage pipe network given a sink. The Breadth-first Search algorithm, Incidence-edge calculation algorithm and Transpose-graph algorithm from Boost Graph Library (BGL) are applied to implement the algorithm for the proposed method. The method provides greater automation and more efficiency but requires less inputs in the process of obtaining the practical drainage pipe network than other commonly used software do. It also lays a foundation for drainage pipe network analysis and related to hydraulic calculations. The accuracy and efficiency of the method is verified by the engineering practices described in this paper.

Stepped Low Pressurized Piping system is a new type of water supply systems, and it has a rapid development in China. For the purpose of a timely and proper supply, excessive hydraulic oscillation or resonance should not be occurred in supply system, so it needs to satisfy the stability conditions. Three Order Elastic Model of hydraulic oscillation has been introduced in pressurized pipelines to analysis the amplitude frequency characteristic of water supply system, and it showed an advantage to study the hydraulic oscillation of piping systems. Then the basis of Stepped Low Pressurized Piping Systems has been provided for design.

The paper presents the construction of the hydraulic calculation model for the heating pipeline network and the resolution method. Modeling method of unit is adopted that bases on the fundamental theory. Meanwhile, the utilization of the graph-theory and the matrix theory gets the coalition between the joints and the pipelines whereby the universal calculation model on the hydraulic calculation for the heating network. Through the transmission matrix method, the node equation is been innovated bases on the routine of the finite element method and the linear method as well. The method allows the quick convergence, iteration speed, delicate accuracy because of the unnecessary initial flow distributing calculation. Ultimately, the adaptability and quick convergence for the model on loop pipe network is demonstrated.

In view of the hydraulic transient problem in heated oil pipeline, an unsteady flow simulation model is built in this paper. The characteristic method and Newton-Raphson method are utilized to solve the model. According to the phenomenon that the light oils would release from the liquid and form void fraction when the pressure is over lowing, the model considers the relationship between the gas release and pressure variation. Then the concentrated cavitations model is utilized to deal with the problem. Based on the model, the computer program is developed to simulate the hydraulic transient. Ultimately, this paper analyses the hydraulic transient behavior at the high-point place which is in front of the middle pump station of certain heated oil pipeline when the pump stopped. The study suggests that it is necessary to consider the cavitations and liquid-column separation in order to ensure the simulation results' accuracy. At the same time, the study shows that analyzing the liquid-column separation phenomenon is also necessary to ensure the oil transport pipeline's operation safety.

The corrosion mechanism of sixteen waterflood pipes of Nanbu Oilfield have been researched through a series of in-house experiments, and the dominant elements that cause the corrosion are revealed, the two elements are the hyper salinity and high corrosive ion content of the injected water quality. And the corrosive degree of every waterflood pipes are contrasted in the same condition, the technique measure that appropriate pipes are selected first and then adequate anti-corrosive agent are adapted is futher put forward. So the well control of corrosion of waterflood pipes can be realized, and there is an important instructing meaning for the production of Nanbu Oilfield.

During the process of urbanization, many of the existing urban water-supply systems need to be expanded to meet the increasing urban water consumption. A precise water network hydraulic model is necessary to perform water network expansion plan. Building a hydraulic model is normally based on the established GIS of current water network, which contains quite huge quantity of information about pipes with various diameters and water facilities including pumps, valves and hydrants. However, much of those data in water network GIS is not necessary for hydraulic modeling and simulation. This paper proposed an auto skeleton method which based on the ArcGIS utilities network analysis toolbox. Firstly the geometric network was established in which the flow directions and the water sources are determined as well as the topology of the water network. Secondly, the branches of network were identified step by step and trimmed provided that the water demands in the branches were accumulated to the root junction of the branches. Thirdly, the pipe loops which can be deleted in the network were also indentified and deleted with demands preserved to the corresponding junctions. Finally, the pipes with same diameters which located at a non-branch route were merged providing the lengths of the merged pipe were not beyond the present value. The proposed method can simplify a complicated network to a hydraulic-equivalent network model in which about 50–60% of pipes were removed, and huge plenty of tedious manual work were thus avoided.

According to the characteristics of dense pipelines, complex laying and strong technologies in product oil tank farm, the safety monitoring and controlling system for pipelines in oil depot is established based on GIS technology. In order to improve the safety performance of oil depot, the system puts emphases on the monitoring the flow, pressure and temperature of all the pipelines. Specially, the advanced seal equipments of storage, oil receiving and delivery are designed in the oil depot. Each tank is connected with nitrogen generator, oil vapor recovery unit and loading area by the pipelines. The system can real-time control the oil gas concentration and pressure of the oil gas space in the tank by regulating flow of the nitrogen. Then oil product loss can be reduced. What is more important, the system can put an end to the fire and explosion accidents and finally the oil depot will come up to the HSE standard.

The pipe corridor indisputably becomes the carrier of the integration of logical distribution in Shanghai chemical industry park. Since there are many pipelines, cables, and related accessories on the pipe corridor, it has constructed a complex spatial relative which requires higher safety management level. This article combines the research and application of several techniques on pipe corridor such as geographic information systems (GIS), video real-time monitoring, gas intellectual inspection, wireless data transfer and spatial position, etc. It mainly has three aspects: pipe corridor spatial data management, real-time monitoring alarm, and intellectual pipe corridor routing inspection. The pipe corridor spatial data management provides the basis for spatial pipe corridor building; real-time monitoring alarm realizes the rapid position, on-site analysis, contingency plan, rapid emergency alarm; intellectual pipe corridor routing inspection provides rapid report to the superior and treatment for the emergency which has effectively reduced the accidents. Now this system is operated in Shanghai chemical industry park and has successfully solved hundreds of emergencies. Until now, there has not been one serious accident.

It has become a trend for urban underground pipeline management to utilize geographic information systems (GIS) to manage spatial and non-spatial data of underground pipelines. Urban underground pipeline networks belong to different owners, due to the great variety and unique characteristics; there are a variety of sources, formats and structures of pipeline data. While using traditional GIS applications, it is difficult to realize the aim that the data is managed and shared uniformly. Modifications and extensions of users' operation requirements often compel developers to adjust the design and implementation of an information system, which makes it difficult to control the period and cost of the development process. Besides, when operating a GIS application after constructing, the user could hardly responds to any changes of the new requirements only by themselves. Hence the efficiency of pipeline management will be inevitably lowered. As to overcome the shortcomings of traditional pipeline GIS systems, this paper presents a new integrated management platform for urban underground pipeline networks. It adopts a GIS service-oriented architecture technology (called it Data Center core technology) and supports three novel development modes, i.e., framework oriented development, plug-in enabled development and configuration driven development. With this technique multi-source heterogeneous data of underground pipeline can be integrated together and managed uniformly, and the expanded and configurable pipeline data model can be set up. In a unified integration framework the management platform based on the Data Center manages all kinds of the operation functional plug-ins in a loosely-coupling manner. The plug-ins is allowed to be freely uploaded or downloaded. Users can customize features of plug-ins according to their own needs and hence configure a unique urban underground pipeline GIS application system to meet the dynamical changes of the pipeline operation flow. The platform integrated abundant plug-ins, such as database construction, management, design, analysis and so on. The Data Center core technique, the integrated management platform along with the plug-ins form a self-contained management solution for pipeline data integration and a ideal data updating mechanism, which may provide effective real- time information services about the comprehensive underground pipeline for municipal public enterprises and government departments.

Rescue workers are expected to arrive at the scene as quickly as possible in the event of a pipeline accident, and optimization of the rescue route is one of the key technologies to solve this problem. We propose in this paper an implementation method for the optimal path based on local DEM data, which takes into account the effects of weather and road conditions and utilizes dynamic programming algorithm with s. We also develop a network topology model on the oil and gas pipelines GIS platform that is composed of related layers such as pumping station, pipelines and highways. This model can determine and display the optimal rescue route from the rescuers' location to the scene of accident, providing a more intuitive visualization user interface.

As complicated network systems, drainage pipeline networks play an influential role for urban environment and safety. Planning, management, maintenance and emergency-response of drainage pipeline network require a series of professional analysis tools, which are closely related to the spatial modality and spatial distribution. From this prospective, GIS provides necessary technical support for the drainage pipeline network analysis. This paper designs a drainage pipeline network analysis platform based on GIS support. It adopts the Drainage Data-Center core technique to integrate and manage drainage-related data resource. It also integrates a drainage pipeline network analysis algorithm library. And based on this algorithm library many professional function plug-ins are implemented and support supervisor's drainage network analysis tasks. Drainage network analysis is based on data stored in different professional system databases, and the analysis platform takes the drainage Data-Center as an embedded system to effectively organize the multi-source heterogeneous data. The drainage Data-Center defines a uniform data access interface based on unified resource locator (a formatted character string). Depending on urban basic topographic data and drainage network data, and through data resource searching and locating, the drainage Data-Center effectively integrates the operation data of public utility departments from pump stations, water quality monitors, users' contracts, the user hotline, etc. The difficulty of using heterogeneous and distributed data is overcome to provide data support and thus an ideal data environment is built for drainage network analysis. Based on algorithms provided in the GIS foundational software such as shortest path analysis, connectivity component analysis, upstream/downstream trace and buffer analysis, we build an algorithm library including professional drainage-oriented algorithms for drainage path analysis, calculation of the pumping station impact area, pollution tracking, accident processing, etc. As another basis of analysis, a drainage pipeline network water level model is constructed using DEM model and water level data from pipeline monitors. The professional algorithm library and the water level model provide decision making support for the drainage analysis, and also form an integrated application environment along with the drainage Data-Center. Based on this application environment, the drainage pipeline network analysis platform realizes various modules such as drainage network design, decision-making for floods, mobile inspection and maintenance, user management and analysis, incident handling and management. This platform follows the SOA criterion and focuses on the openness and interoperability of the functions and results of analysis. It supports access through personal terminals, internet, and embedded device. Supervisors can to extend its functions by customizing, assembling and developing to meet needs of different levels. This platform can provide a scientific basis for drainage network planning and reconstructing, improve the efficiency of emergency responds, and advance the level of daily operations such as inspection and maintenance, and hence ensure progress of urban environment and social development.

In view of the problem that how to select the natural gas pipeline's optimization regulation schemes, the analysis method is utilized to select the pipeline's regulation schemes evaluation indexes which include the pipeline's flow rate, operation income, risk and gas storage capacity. According to the emphasis points of the regulation schemes, the AHP method is adopted to calculate the indexes' weights. The gas pipeline's operational database and the optimal operation scheme are constructed in this paper. Based on the grey relational analysis method, a multi-objective comprehensive evaluation mathematical model which considers the indexes is established. The model measures the degree by which various regulation schemes approach the optimal one. Then the priority order of multiple schemes is determined. The computer program is developed to evaluate a pipeline's regulation schemes. The study shows that the model and algorithm discussed in this paper are feasible.

It is a complex process that dry air dries natural gas pipeline, the same that heat and mass transfer at the same time. It is a very important process before long distance natural gas pipeline goes into production too. This paper discusses the basic principle of dry air drying, builds the mathematical model for drying, and analyzes the effects to drying efficiency from some factors, such as the prime water content, the water content of saturation air, the flow of dry air, the distribution of liquid water and ambient temperature. Combined with the working practice of drying technology in west-to-east gas pipeline project, some suggests how to improve drying efficiency are put forward. There are some reference values for drying of other natural gas pipeline engineering.

Karun River is located in the South- Western part of Iran (or the North- western area of the Persian Gulf). Irrigation water should be transmitted from Mared channel into the East bank of the Karun River through siphon design at the River bed. This paper will try to show the economical comparison through the HDD, Fabricated pipes, and TBM, PE pipes with artificial intelligence designing (AID). Total cost of AID will be computed less than 1/4 of other mentioned methods. AID is needed to invent more connection with moving and rotation behavior. Also, buoyancy forces will be obstructed to fix in the bed through micro piles nails at the siphon bed which could be guaranteed the flow current and floating behavior safety. Complimentary design can be modified to approve AID for military purposes through the more research and tentative tests in the laboratories.

Gas transmission pipelines are actively being constructed in China at present. The optimal selection of design alternatives for natural gas pipeline systems is a very complex problem. It is associated with a lot of fuzzy factors such as the cost of the construction engineering and reliability. In this paper the problem of alternative selections of gas transmission pipeline systems is studied. The significant factors influencing the optimal selection of the natural gas pipeline are regarded as fuzzy variables, including diameter, wall thickness, pressure, compression ratio, number of compression stations, expenses, reliability, etc., with different corresponding weights. The method has been applied to a practical example as described in the paper. The statistical data were transferred into fuzzy numbers by adopting linear membership functions. The fuzzy comprehensive evaluation method was adapted to evaluation design alternatives for the gas transmission pipeline. The weights were determined by the analytic hierarchy process (AHP) method. The judgment indexes were obtained through fuzzy relationship operations. Consequently, the optimum designs for natural gas pipeline systems were obtained. The fuzzy decision method could be the theoretical basis and the new design method for the engineering design of natural gas pipelines.

The stress condition of the soil in the interaction system between soil and buried corrugated steel pipes is greatly different from that in elastic half-space homogeneous earth. There are various earth pressure concentrations due to the soil structure interaction between soil and the steel pipes. As a result, the actual vertical soil pressure on the pipe's crown is smaller compared to the weight of the soil prism above the pipes. The flexibility of the corrugated steel pipes is smaller than that of the reinforced concrete structure and the soil pressure will change as the flexibility of the pipes changes. Different flexibility parameters of the steel pipes are selected to analysis. Based on finite element analysis and existing theoretical theories, the modified method of the soil pressure around the steel pipes is proposed. Then, referring to the method of internal force calculation with consideration of displacement compatibility between the conduit and the soil around it, further modification is proposed according to the characteristics of corrugated steel pipes' stiffness. In the end, the comparisons between the finite element analysis results and the theoretical calculation are analyzed. The calculating method is proved reasonable.

In order to improve the arrangement of the gathering and transferring of oil-gas pipe network, the mathematic model for solving the multi-objective optimization problem were established. NSGA-II (Non-dominated Sorting Genetic Algorithm-II) program which has a good global optimization has been compiled to improve the gathering and transferring of oil-gas pipe network performance. Positions of middle stations were selected as the design variables with investment cost and hydraulic loss of pipelines as optimization objectives. Many techniques in optimization program, such as the real number encoding technique, the random sampling based on expanding the research space, single-point crossover and uniform mutation had been used. The system of optimization method is formed to be utilized for optimization of gathering and transferring of oil-gas pipe network. Lastly, through one engineering project of the gathering and transferring of oil-gas pipe network, it is shown that economy and the hydraulic performance of the optimized gathering and transferring of oil-gas pipe network has got improvement to some extent.

Based on a pipeline-soil coupling model, the process of a submarine pipeline impacted by dropped objects is analyzed using the nonlinear dynamic finite element method. The Ramberg-Osgood model is adopted to model the constitutive relationship of the soil. The nonlinear dynamic governing equations are solved by the Newmark and N-R iteration methods. The influence of various factors on the impact deformations is analyzed, including object shape, impact angle, friction, concrete thickness, internal pressure and burial depth of the pipeline. As expected, the results confirm that an object with the shape of a cube or sphere causes a larger extent of the dent region than that of a cone, but the depth of the dent is relatively small. The depth of the dent increases with a decrease of cone angle, corresponding to a sharper object. The maximum depth of dent on the pipeline occurs at an impact angle of 90°. In addition to these expected results, it is seen that friction has relatively little effect on the impact deformation. A concrete coating provides good protection, but only when the weight of the dropped object is small. Internal pressure increases the stress of pipeline, but decreases the depth and extent of the dent. The burial depth of the pipeline can provides effective protection. The method presented in this paper is more appropriate for practical pipeline problems than that of current methods.

Apart of the West-East Gas Pipeline and Product oil Pipeline projects has to traverse the Loess Plateau where the regional topography is complicated, loess gullies or slopes are more. There are great difficulties for laying pipelines due to the Loess Plateau. Using large scale excavation method for the loess gully or the slope, the project quantity is not only large, but also the destruction on the environment and vegetation is serious. In addition to these, the landform restoration and the protection of hydraulic surroundings are rather difficult. So, the crossing of long-distance oil and gas pipelines in the loess gully or the slope adopts the combination of inclined well and horizontal tunnel. Choosing the design parameters to ensure security crossing of pipeline is one of the important topics. According to the slope stability analysis, some problems about oil and gas pipelines crossing the loess gully or slope were studied based on the theory and numerical methods in this paper, such as the selection of non-linear elastic loess model, the determination of surface wellhead position, the reasonable section of inclined well, the reasonable position of the operating pit, the suitable support method under the inclined construction. The obtained conclusions are useful to the design and construction for gas and oil pipeline engineering.

For high safety and quality in construction and operation of buried conduit pipes and pipe jacking, it is necessary to carry out static calculations and proof for stability and serviceability under consideration of specific technical conditions. In this paper, firstly the importance of static calculations for buried conduit pipes and pipe jacking is shown with the help of some practical examples. Then, the basic principle and calculation methods in both of the current German standards A 127 and A 161 are described for flexible and bending resistant conduit pipes and pipe jacking by using different materials. The fundamentals and the German experience for static proof, e.g. safety standards and concept, material parameters in short- and long-term state, soil-mechanical parameters, soil and traffic loads, water pressures as well as driving forces in pipe jacking under straight and curving movement conditions, are illustrated. Both of the German standards have been entered for example in the list of European Code EN 1295 and well accepted in the international world for the static calculation of buried conduit pipes and pipe jacking. At the end of the contribution, the program system "Easypipe" is introduced. This software has been developed upon A 127 and A 161, accepted by German union for water management, sewage water and waste (DWA), and widely used in Europe. For the user in the practical piping engineering, it could be a very helpful tool in the evaluation of the stability and serviceability of buried conduit pipes and pipe jacking.

There is expected to be an increase in oil and gas pipelines across frozen areas with the increasing oil and gas demand in China. The engineering problem of laying pipelines in permafrost areas is discussed. In this paper, the amount of frost heave is calculated using segregation potential model, and the finite element model of pipeline-soil system is established including considering creep effects of the frozen soil. The model can calculate the amount of frost heave based on the changes of surface temperature and also can calculate the stress and strain with considering the thermal stress and non-linear constitutive relation of pipelines. The examples of pipeline with the diameter of 1219mm, wall thickness of 16mm, 19mm and 27mm have been calculated and the analysis indicates that the displacement of the earth's surface in temperature of –10° ~ 10° is about 0.39m and the frozen deep is about 4.25m. The frost heave of soil results in pipe bending and the maximum bending occurs near the interface of two different soils. Axial compression strain of the pipeline may be led by pipeline bending and thermal stress. The example demonstrates that pipeline with the wall thickness of 16mm occurs local buckling in the area of upward bend.

In the design of drainage engineering, in particular, in the analysis and hydraulic calculation of a drainage system, the location of primary and secondary drainage paths is a kind of foundation work. However, at present, the location of primary and secondary drainage paths in commonly used software for the design of drainage engineering still depends on the users' manual designation, which causes errors easily with low efficiency and without any automation. To implement the auto- location of primary and secondary drainage paths, this paper applies graph theory to analyze the characteristic for the composition and the data structure of a drainage system, an effective method based on the length is proposed. The method is designed and implemented by the iterative idea on the basis of the shortest-path algorithm and its performance is proven by the engineering practices described in this paper. It can be widely used in the analysis and related hydraulic calculation of a drainage system.

Aimed at phenomenon of Shutdown Batching Pipeline, Setting up 3D unsteady Contamination Numerical Calculation modal, from mass and Momentum transfer coupling, based on PHOENICS3.6 software. The Analysis of Numeric Examples shows that the effect of Shutdown on Contamination, and Contamination mechanism of former diesel oil - back gasoline under the upgrade and the downgrade pipeline and so on.. Finally, in the different working condition, the Contamination effects of shutdown transportation are different, resulting in the concentration curve variety regulation of shutdown transportation

Entropy is taken as an indirect index to measure the reliability of gas distribution network. The entropy function is set up. According to principle of maximum entropy, the maximum entropy model is established. With the relative entropy which is the ratio of actual entropy and maximum entropy as the reliability constraint, the diameter optimization model is set up and solved by improved genetic algorithm. Through actual engineering example, the optimization model with reliability constraint and optimization arithmetic in this paper can acquire satisfied solutions to engineering project and have certain reference value for diameter optimization design of gas distribution network.

For the difference of iron and manganiferous groundwater qualities and spatial distribution between the groundwater sources and service regions, different layout of groundwater biological removal of iron and manganese system should be adopted. It was one of the conditions to prevent the ferromanganese sediment silting raw water pipelines to ensure the service lives of water pipelines. It was important for the security and stability runing of the entire water supply system. In this paper, the layout relationship between the groundwater biological removal of iron and manganese system and the water supply network were studied. As following recommendations had been made: 1, to minimize the oxygenation opportunity in the process of iron and manganiferous groundwater be taken and delivered; 2, to take into account of removal of iron and manganese water works should be as close as possible to water source during the establishment of the taking water, purification and delivery of water systems, in order to reduce the length of transmission of water line. Use of these recommendations in practice, achieved good results: the groundwater biological removal of iron and manganese treatment plant had a daily handling capacity of 200,000 tons and the effluent iron, manganese all was trace amount and met the Chinese standards for drinking water quality.

Economic frictional factor is the important parameters in the heating network design, which impact the investment of heating network. In this paper establishment the mathematical model based on the principle of minimum cost, from the angle of economic consider the total investment of pipe network's infrastructure construction, the annual cost of transportation heat medium, the annual cost of heat loss, the differential method to solve the cost model, determined the economic frictional factor of different heating scales and quantitative analysis of impact of frictional factor, provided a reference for engineering design.

Frost heave is the primary factor for potential destruction of the permafrost pipeline. Considering the Fenghuoshan area of the Ge-La Pipeline, the paper develops the finite element model for frost heave, and determines the amount of frost heave, frost stress around the pipe and Von Mises equivalent stress of the pipe wall, based upon the coupled thermo-mechanical method. The results indicate that the direction of frost heave is essentially vertical; the maximum frost stress occurs in the soil adjacent to the central section of the pipe, and the maximum Von Mises equivalent stress occurs at the top of the pipe. Based on a sensitivity analysis, the frost stress and Von Mises equivalent stress diminish with an increase of trench width and buried depth. The relationship between the frost stress and Von Mises equivalent stress and the pipe diameter and trench obliquity is rather complex. The frost stress value reaches a peak when the diameter is 150mm, and the Von Mises equivalent stress value reaches a peak when the trench obliquity is 10 degrees. The above results and methods have important significance for the design and construction of a permafrost pipeline.

Based on the relationship of relevant parameters for pipeline reliability design, an inverse reliability design model of oil/gas pipelines has been developed. The resulting equations based on the pipeline design parameters (such as material properties, dimensions) are deduced from the s–r interference model, and the boundary conditions and methods of solution are discussed. As an example, an actual pipeline is designed using the model. The overall results indicate that the proposed model rapidly convergences with sufficient precision for solving practical problems. And the results of the calculations are in good agreement with actual measured or observed values. The new model is efficient and suitable for oil/gas pipeline reliability design for which the reliability level is specified. The inverse reliability design model presented in this paper has more general application, and can be adopted to solve various inverse problems of other engineering fields.

Condensate gas is a multi-component mixture. The condensed liquid is caused by the change in temperature and pressure along the pipeline, which results in two-phase flow. In the light of the characteristics of mixed phase transportation, the models of composition distribution and stratified gas/liquid steady flow for condensate gas pipeline are established according to the principles of thermodynamics and fluid mechanics, then the difference methods are used to solved those models, the approach of solution is given and computer program are developed. It can be used to predict composition distribution, pressure, temperature and velocities along pipelines. A comparison of theoretical calculation with published experimental data for condensate gas pipeline was performed. The method described in this paper is useful for the design and operation of condensate gas pipelines.

When setting up a micro-scope pipe network model, the model should embody the details of Topological Structure as much as possible. It takes a lot of time for solution of the micro-scope pipe network model. Meanwhile, since it is very difficult and time-wasting to solve the large-scale mixed-discrete nonlinear model, the research for pipe network optimization, such as network optimal modification, optimal scheduling and so on, shows that optimization calculation which use the no simplified hydraulic model will take additional time or even become unacceptable. So it is very necessary to utilize the network simplification technology. Aiming at some limitations in the current micro-scope hydraulic model of water supply network simplification technology, such as not being realized automatically and only getting a single objective for simplification calculation, a new method of "network simplification in accordance with such principles as designated precision, dendritic network simplification, simplification in the same flow direction and simplification in the series pipes with the same pipeline properties" is proposed in this paper. By using this method, pipe sections and joints simplification, and pre and post model's correction results keep consistent in a maximum extent. This pipe network simplification can be realized by running the procedures and can adapt all kinds of Topological Structures and complicated network. In the simplification process, operators don't need to do anything and after simplification, model's calculation accuracy is totally met with the requirement of network calculation. When the network system load and running conditions vary at a little extent, the calculation accuracy can totally be taken place of original network micro-scope model's results and can be used in the optimal calculation of network optimal modification, optimal scheduling and so on.

An optimization method is presented for X70 steel tunnel pipeline design construction based on an analysis of mechanical issues. Considering the Sichuan-to-East-China Gas Transmission Project tunnel pipelines, two modes for placing the long distance large diameter tunnel pipeline are studied, including buttress placement and embankment buried placement. Using the principle of virtual work, a formula is derived for determining the push force of pipeline anchor block at the tunnel exit. The tunnel pipeline placement parameters are analyzed considering vertical and horizontal bending, using an elastic stability model and the energy method. The parameters consider multi-span continuous beam stability, span length, placement length for stability, radial and upheaval stability. The formulas are presented as a function of the various parameters. Based on the research results, a computer program has been developed. The key mechanical parameters for the tunnel pipeline design construction of the Sichuan-to-East-China Gas Transmission Project are optimized. Applying a commercially available pipeline finite element software tool, the entire design scheme has been analyzed for pipeline stress and displacement in order to verify feasibility of the placement parameters. The results show that the design construction parameters optimization method for tunnel pipelines can satisfy engineering design requirements.

In order to solve the problem of environmental electromagnetic interference to measuring instrument, a new 3D shape measurement method of trenchless underground pipeline is presented in this paper. At first the geometric information of pipeline such as the curvature and the slope of the pipeline axis are studied. Then the 3D shape of the pipeline is reconstructed by the geometric information. The optical measurement method and the 3D shape reconstruction algorithm of the pipeline are also analyzed in the paper. Finally, the experimental prototype is introduced and the result of a set of pipeline experiments is presented.

Locating buried pipelines using ground penetrating radar (GPR) is necessary to trenchless construction. The target reflected waves are usually disturbed by the clutter and the stochastic noise, and then it's difficult to distinguish the pipelines. The direct wave is one of the main radar clutter interference affecting target echo for pipelines GPR monitoring, which has great relevance. In this paper, a newly interference eliminating technique based on empirical mode decomposition (EMD) for pipelines GPR monitoring is presented, and apply it to reduce the clutter of the GPR. It uses the joint energy-frequency-time distribution characteristic of EMD and their correlations on the direct wave, target reflected signals and stochastic noise in multichannel GPR profiles, we obtain a finite number of Intrinsic Mode Functions (IMFs) which have physical meaning via EMD of the GPR trace, then these IMFs can be decomposed into the product of eigenvalue matrix and eigenvector matrix by using K-L transform, and the size of the eigenvalue can reflect how much they are relevant among them. Selecting data with small evignvalue can rebuild irrelevant signals and suppress the clutter. The validity of this technique has been proved by the real data to eliminate interference for pipelines GPR monitoring.

The Transient Electromagnetic Method (TEM) has some unique qualities that make it amenable to pipeline detecting and environmental monitoring. TEM is carried out to locate the groundwater pipelines and to detect the spread of groundwater contamination in an abandoned industrial service site. Based on the analysis of electrical conductivity and in-phase electromagnetic component of the survey area, the geophysical anomaly zones are delineated. The TEM method is sensitive to the conductive layers and demonstrates the ability to measure small changes in subsurface properties involving groundwater. The measurement shows the position of groundwater pipelines and the behavior of groundwater contamination. The study is beneficial to help waste management processes and to determine possible locations of monitoring wells in the survey area in the future. The study shows that the TEM technique has a high accuracy, and that it is quite suitable for providing a rapid, reliable and time-saving means for the maintenance and renewal of the underground pipeline preceding the drilling.

This paper discusses the findings of a project funded by the U.S. Strategic Highway Research Program (SHRP 2) to assess the potential for technical innovations in locating utilities, record keeping and marking of utilities and determining the operating characteristics and condition of a utility. The SHRP 2 program of the U.S. Transportation Research Board has been funded by congress to provide a targeted, short-term research program addressing key issues in highway transportation. The overall goal of the Highway Renewal program is to develop a consistent, systematic approach to performing highway renewal that is rapid, causes minimum disruption, and produces long-lived facilities. One of the important thrust areas of the SHRP 2 program concerns the impact of utility issues on highway renewal projects and several aspects of this issue are being studied.

Ground Penetrating Radar (GPR) is an important means to detect underground pipelines. For a long time, there are so many baffling problems for GPR, such as: to distinguish multiple pipes which are close together, to detect the material and diameter size of the pipe, the detection of small diameter non-metallic pipelines, etc. Since an RIS-based ground penetrating radar from Italy has been applied to detect pipelines, great progress has been made in the solutions to these problems. Generally speaking, many close distance pipelines can't be distinguished. Even the closed metal pipes can't be distinguished by the pipeline detectors, but can be easily distinguished by GPR now. Through analyzing radar images, the materials of the detected pipes and the materials inside the pipes can be distinguished and the diameters of non-metallic water supply pipes can be calculated using the spacing of the intervals of radar reflected waves. Good progress was also made in the detection of small non-metallic pipes (with diameter less than 300mm).

With the development and application of Trenchless Technology and mining intersected holes construction, Horizontal Directional Drilling Technology (HDD) depth measuring while drilling and the technology of locating have been increasingly used. The theory of depth measuring has caused extensive concerns. To improve the accuracy of depth measuring in horizontal directional drilling is the goal for field engineers. This paper introduced a model of the receiving antenna with two coils for electromagnetic depth measuring in horizontal directional drilling, and discussions on the depth measuring error for different conditions. Some cases were analyzed by MATLAB software. It also provided the solution to the problem of the blind area while depth measuring. Special experiments have been done to verify the model. The results indicated that the trend and direction were congruent between the experimental and the theoretical curve with tolerant errors, and it was confirmed that the depth measuring model is acceptable. It can be referred in practical engineering.

Risk assessment based on quantitative method is considered as an important safety management method. The potential risk of the natural gas pipeline can be controlled under the accepted level by using the quantitative method of risk assessment. This paper focuses on developing a quantitative method for risk assessment of natural gas pipelines. The hazards of natural gas pipeline are analyzed and distinguished. The heat radiation and shock wave are the main manner which can result in disaster. And the failure rate and consequences of natural gas pipeline incident are proposed. The method for calculating the probability of individual death by heat radiation is proposed. Individual risk and social risk for sample natural gas pipeline are calculated by using this method and historical data of European Gas Pipeline Incident Date Group.

In exploration wells, particularly in deepwater exploration wells, such as deep or ultra-deep exploration wells, the information regarding formation pressure has many uncertainties because of the lack of seismic data, logging data and daily drilling report. The present casing point selection methods based on the deterministic formation pressure data did not take these uncertainties into account and the results could not satisfy field engineering requirements. This paper presents a quantitative risk analysis method for quantitatively analyzing the risk of the casing point selection design. The model includes four sub-models for determining the quantitative risk due to lost circulation, kicking, collapse and sticking. The results can provide valuable information for designers. The results of the application of this method to an ultra-deep exploration well northeast of Sichuan province are consistent with actual experiences.

As city underground pipelines are invisible, destroy can't be detected in time and the sudden breakdown is inevitable, which will cause the huge property damage of industrial production and people's daily life. At present, there is no unified standard for appraiser and evaluator, this paper evaluates its Durability and reliability according to detecting one actual underground pipeline's position and corrosion status in Beijing, and calculates its aseismatic deformation capacity, which provides a base for the further strengthening design and provides reference for the theoretical research of underground pipelines' evaluation.

It is important to use risk analysis method to manage the city gas system. Through the analysis of difference between long-distance pipelines and urban buried gas pipeline, we know that the long-distance pipeline risk analysis in Pipeline Risk Management Manual does not apply to the city buried gas pipeline. In fact, the environment in which the city gas system exists is complex, there are many factors which can affect the system risks, and various factors may also be associated, these lead to difficulties in making accurate judgments in the actual analysis of the system risks. In this paper, through analyzing the data type and structure of the influencing factors for the city gas system, we select an appropriate analysis model in the SPSS statistical software, screen on a great amount of data contained in the system itself, select the data information directly related to system risk, and help to establish a risk assessment indicator system which is suitable for domestic city gas system.

In recent years, the frequent occurrence of gas leaking of delivery pipes has posed great threat to the delivery operation, and brought about great loss of national economy and people's lives and property. By using Pasquil-Gifford model, based on the intrinsic features of natural gas, this paper analyzes the forms in which gas leaking may occur. Models are built to calculate the degree of gas leaking occurred on different conditions, the diameter of flame, and the radium of explosion so as to estimate the range and degree of the gas-leaking, and to minimize the damage to human beings and environment. Finally, according to the models, the consequences caused by gas-leaking can be well studied and evaluated.

The safety management is among the most important management work for oil and gas pipelines. As an alternative, the risk grading division based on WebGIS is being considered to improve safety management. An information management system for oil and gas pipeline based on WebGIS has been established using ArcGIS Server as the developing system of WebGIS, SQL Server as the database to store pipeline data and ArcSDE as the GIS Server. According to the practical pipeline situations, the expert grading method on risk assessment of oil and gas pipeline set by W. Kent Muhlbauer was modified. An analytic hierarchy process (AHP) was introduced to comprehensively evaluate the expert grading method, and a categorization method for the risk of oil and gas pipelines was proposed. Finally, it was demonstrated with examples that this improved categorization method based on Web GIS is more intuitive and easier to apply.

Underground pipeline is the lifeblood of city. So, risk estimation on urban underground pipeline is very important. Risk estimation is a systematic, specialized, scientific and comprehensive work and is the major work of public safety and emergency management. The following will be the major researches in this paper. The first is the mechanism and procedure of risk estimation. The second will be around of underground pipeline risk estimation method and risk classification based on risk management basic theory and underground pipeline accident characteristics. The last will adopt determined risk estimation method to estimate the underground pipeline risk of a sample city.

Gas system is an important part of the city lifeline system; it mainly includes gas pipelines and regulator stations. The risk of regulator station is also an important component of the gas system risks, in the previous risk assessment of the pipelines, it is only considered in the factors of third-party damage as ancillary facilities to the ground. In this paper, through a large number of accident investigation, and based on the analysis of risk and harmful factors for the gas regulator stations and pipelines, we exploit probability importance degree and structure importance degree in fault tree to amend assessment indicators, we use fuzzy comprehensive evaluation method to establish an overall risk assessment model which is suitable for the city gas lifeline system.

This paper presents the translucent storage encryption method that gives attention both to the practicability and safety for data storage and use for the underground pipeline system database. Data safety is the most important factor for the large-scale database, especially for underground pipeline system database, because this database is that not only includes a large numbers of data that are useful for underground engineer, construction contractors and asset manager, but also vast sensitive data that is relative to commercial interest of some organizations, companies, local government or even the national safety. Various data encryption methods have recently been proposed to protect sensitive data in the database, among which the techniques of Transparent Data Encryption and Non-Transparent Data Encryption are popularly used. Based on the two techniques above, a novel data encryption method, Semi-Transparent Data Encryption (Semi-TDE) will be developed in this paper to address the data safety problems with the underground pipeline system database.

This study has deduced a simple method about calculating piston wind speed and airflow distribution by a quasi one-dimension numerical model. It also has found the influence factor of piston effects such as train speed, the frontal area ratio of train to tunnel, tunnel length and so on. In order to verify the feasibility of the method, this study used the authoritative subway environmental simulation (SES) computer program to simulate the piston effects. The simulation results show that the air speed and flux distribution are very important design parameters for ventilation by piston effects for subway tunnel system.

The traffic load was simulated by stable simple harmonic load. Taking the most dangerous condition, the advantageous effect of the pipeline connected to the manhole was neglected. With the effect of soil on the manhole simulated by Voigt model, the longitudinal vibration equation of the manhole in viscoelastic soil was established considering its gravity. The semi-analytical solution in time-domain and the curve of manhole settlement were obtained with Laplace transform and inverse Fourier transform. A three-dimensional finite element model, considering the nonlinear mechanics behavior of the manhole under traffic load, was set up to validate the reliability of the theoretical method using the software of ANSYS. The finite element model result showed that the curves of manhole settlement gained from these two methods were nearly consistent, which shows that the proposed theoretical method is feasible to analyze the manhole settlement under traffic load.

With the continuous development of the nationwide urbanization, the urbanization utility construction becomes more and more development and perfection, especially the trenchless technology has been applied to the urbanization utilities construction and also brought great changes of this construction fields. The authors discussed the problems based on a city's storm water - sewage separation trial section project using Horizontal Directional Drilling (HDD). As well, this paper put forward the sewer pipelines construction quality control methods according to the requirement of sewer pipes.

In this paper, in view of poor drainage of Lei-Yi Highway median horizontal drainage system, according to the structural characteristics of the road, making use of advantage of Directional (Guided) Drilling Technology, the comparative analysis of several different methods of drilling trajectory is made, and the method that uses the Directional (Guided) Drilling technology and grouting technology is put forward in the highway transverse drainage improvement project. The potential difficulties are solved in the construction process, such as hole enlargement and roadbed subsidence. The field test shows a very good drainage effect is achieved. The paper has provided the solution ideas for the similar drainage improvement project.

Highway culverts and drainage structures have the peculiarity of being characterized as both buried pipes in small diameters with no access or worker entry and larger ones with the possibility of manual inspection and repair/renewal. As such, asset management procedures for culverts are a complex issue. Trenchless technologies are not disruptive to transportation systems and provide safer construction operations for both workers and the general public and are ideal solutions for culvert renewal projects. If they are used in the appropriate application, they provide extended design life to existing culverts and drainage structures that may double or triple the original design life of these assets. However, each trenchless method has its own capabilities and limitations, and should be selected based upon existing conditions in order to be effective. This paper presents an overview of ASCE Manual of Practice (MOP) No. 120 entitled "Trenchless Renewal of Culverts and Storm Sewers." The objective of this MOP is to describe technologies used by engineers and transportation professionals in renewing culverts and drainage structures under roads, railroads, airport runways, streets and similar structures.

The text has discussed and analyzed the important parameter—build-up intensity (the drift angle change of drilling hole in one meter length drilling, degree/meter) which influences the hole section designed(Dai, 2005). It has established the build-up intensity model through the over stress analysis to drilling tool and has obtained the formula of build-up intensity affected by the resistance of soil and the curve of drilling in the preliminary stage of drilling. Then it analyzes the primary factors which affect the build-up intensity in the basis of formula and has drawn some conclusions. This article also gives qualitative and supplementary showing to the rule of build-up intensity in the case of continuously drilling through lab tests.

In this paper, aspects of construction technology of horizontal directional well of soil environmental remediation are introduced particularly, including construction procedures, assembly of pipeline, packer, well screen, insulation, cementing, well washing. At the same time, experimentation is introduced also; Problems and noticing proceeding of experimentation is analyzed; Experiences and lectures in the experimentation are summed up in this paper.

With the development of China's national energy strategies, the construction of long- distance pipelines of the natural gas is increasing. A spate of legislation emerging from government at all levels aims ultimately to restrict open-cut excavation for construction of underground gas pipelines crossing high-grade highways. Pipe- jacking, as a new construction technology, for the trenchless installation of underground pipelines, is widely used for long-distance pipeline for crossing high- grade highways, due to its high-performance, high-quality and low cost. At present the theoretical analysis of pipe-jacking design lags to its successful practical application for the long distance pipelines. We have considered integrated stresses application when jacking pipeline under the influence of vehicle loads and have proposed a computational method of jacked pipeline under the condition of crossing a high-grade highway. The results may be used in the design of pipe jacking, mostly including a determination of the jacking force on the pipeline and bending moments acting within the structure. Using the example of a jacked pipeline passing beneath a high-grade highway in the second-line pipe project of West-East Gas Transmission, the results of the calculation method proposed in this paper are in very reasonable agreement with those obtained by the normative approach.

At present, pipe jacking is mainly used for the laying of drainage pipes due to the limited kind of pipe. GRP (Glass fiber reinforced plastics) pressure jacking pipe is one of pressure pipe which can be used for jacking pipes. This new type jacking pipe has many advantages, such as light, high strength, corrosion-resistant, long life and so on. Shanghai Yangtze River Phase III pipeline project of water transportation use this jacking pipe firstly, pipe nominal diameter of 2300 mm, the pressure rating of 0.6MPa. Through the design of large diameter GRP pressure jacking pipe, numerical analysis, properties testing and on-site monitoring in practical project, we can introduce this new jacking pipe and show the feasibility of applying this pipe and its characteristics, which has significance for other pipe jacking projects.

A submarine pipeline on cohesive seabed was investigated using an integrated surveying system, including a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a swath sounder system. By analyzing the pipeline field investigation data, the concepts of `side scour' and `down scour' were proposed for the local scour around submarine pipelines in cohesive beds, which probably result from tidal currents and hurricane-induced currents respectively. The submarine pipeline in the deep water regime (with water depth > 37m) possibly buried itself due to hydrodynamic effects, submerged weight and the side scour. The maximum burial depth of the pipeline was the total effects of that caused by gravity and the side scour respectively, while the later effect corresponds well with the maximum side scour depth.

At present, various predicting models are developed to predict pull-back loads for HDD projects and results at the end-point of pull-back derived from them fit quite well with the results obtained in field tests. However, the maximum loads that usually occur in the process of pull-back can not be predicted by any of them because of slurry drag effects not considered adequately. There is a crossover point in the process of pull-back where slurry reverses its flow direction while the maximum loads usually occur, since drag effects take a large proportion in total pulling force for small and medium scale HDD installations. The paper presents a model to calculate pressure drop of slurry in concentric annulus assuming laminar flow of power-law fluid. Crossover point is located by comparing pressure drops of two kinds of annulus (pipe in borehole and drill string in borehole). Pressure drops are calculated based on equation prescribed by the Society of Petroleum Engineers (SPE) as well. The result calculated from the model agrees with HDD field test data more accurately compared with the SPE equation. It is observed that the rheology parameters under low shear rates have a significant impact on pressure drop calculation.

For concrete pipe-jacking, there are no clear design codes for the concrete roof in China yet. But the design standards, adopted in designing concrete pipe-jacking, are mostly in connection with water norms or analogy experience. Based on actual projects, the top management of the calculation and checking process of circular concrete structure were discussed in detail in this paper.

As public works agencies look to install new buried pipelines in an economical, environmentally-friendly, and minimally intrusive manner, the adoption of trenchless technologies such as horizontal directional drilling (HDD) has increased. Today, HDD equipment is engaged in projects involving pipeline installations of utility networks such as water, wastewater, telecommunications, electrical, telephone, oil product, and natural gas. This increase in utilization of the technology has resulted in a greater potential for risk and damage to subsurface and surface features. Designers and owners are continually exploring methods to assure quality on HDD projects. This paper discusses quality assurance and quality control measures to mitigation installation- related issues including: 1) heaving of surface features; 2) damage to existing subsurface structures; 3) product pipe damage; and 4) surface settlement. Adherence to these recommendations will better increase the likelihood of a successful horizontal directional drilling project.

Technology of box culvert within pipe roof is firstly pushing small diameter pipes in the outer of box culvert then forming pipe roof in which the box culvert is pushed. The box culvert attitude control is very important to the channel's clearance and slope in the process of box culvert being pushed within pipe roof. Firstly the pipe proof attitude control is studied in this paper. At the same time the computing model of box culvert is set up to analyze its deviation on the assumption that the pipe proof is an elastic foundation beam. The affecting factors such as excavation length, grouting pressure and excavation speed are also studied. Then the technology of horizontal and vertical attitude control of box culvert is researched in the construction project. These research results have theoretical and practical significance for box culvert construction.

The methods adopted for pipeline crossing usually are: directional drilling crossing method, mine tunneling method, shields tunneling method and so on. The engineering geological conditions have decisive impact on the pipeline crossing design and construction plan formulation. For the project of pipeline crossing in the middle reach of the Yangtze River, firstly, the crossing point needs to be chosen based on the engineering geological conditions of the crossing Yangtze section, then the crossing method should be decided. In order to choose reasonable method, the pipeline crossing methods and suitability of engineering geological conditions should be fully studied.

Due to its advantages, trenchless technology has been widely used all over the world during construction of underground pipelines, and horizontal directional drilling is the most popular trenchless technology. Because a drilling rod is subjected to the most complicated stress and the harshest working condition among all components in a horizontal directional drilling system, this paper lays emphasis on stress analysis of drilling rods. The finite element method and the computer software ANSYS are used to calculate the stress in the drilling rod. Also, the effects of torsional moment on the stress value and distribution are analyzed as well. The results of the above analyses give the location of the maximum Von Mises stress along the rod and indicate the relationship between maximum stress and the curvature radius of drilling rod. Generally speaking, the maximum stress usually occurs near the joints of the drilling rod, the rod stress decreases with an increase in curvature radius, and an increase in the torsional moment on the drilling rod can significantly increase the rod stress.

Trenchless Technology has become more sophisticated and widely used in many fields in recent years. But there are still some construction problems in different geological conditions especially in rock. Due to the complexity and particularity of rock, the trenchless construction technology applied to it is completely different from to soil. As well as there is not very perfect construction technology and methods still, which bring a big risk. Based on existing theoretical research, the characteristics of rock and the construction experience, this paper mainly discussed Drill hole Mud Motor and Roller Cone Bit applied to Trenchless Technology in Rock, the main contents are as follows: first of all, introduced the properties of Rock, and then discussed the working principle and the advantages of Drill hole Mud Motor and Roller Cone Bit which the key point was to make work together smoothly. Afterward to choose the drilling equipment to support them such as Mud Pump, Rig, Drilling Mud and other drilling tools. Finally, according to a project example, general construction problems and solutions were analyzed. For example how to control the construction time of pilot bore and drilling deviation; what we should pay more attention on the process of reaming, cleaning and towing pipe. It will provide some valuable references to the TT of similar nature.

Oblique well is used for traversing the loess gully or slope in the oil-gas pipeline engineering. It is an important problem how to determine the limit obliquity of inclined well for the oil-gas pipeline crossing. Based on the stability analysis theory of slope and the theoretical calculation formula of the limit obliquity of inclined well, the limit obliquity of inclined well with different slope heights, slope angles, internal friction angles, cohesion and weights are calculated based on a code written by the authors. The sequence of sensibilities is listed by orthogonal design. The results show that the slope angle is the key factors that influencing the limit obliquity of inclined well and the influence degree from big to small is slope angles, internal friction angles, cohesion, weights and slope heights. Therefore, the emphasis should be placed on the selection of slope angle in the design of limit obliquity of inclined well for Oil-gas Pipeline Crossing and the internal friction angle for the slope with definite angle as well.

With the starting of the West-East Gas Pipeline Project recently, the hazard evaluation of underground crossings of landslide areas has become of increasing interest within China as well as overseas. Due to landslide failure deformation, the pipeline could fail resulting in a great loss. Therefore, the arrangement plan of pipeline underground crossing landslide area is one of the key problems. A typical landslide in Western China area was taken as an example, from which the interaction model of landslide and pipeline was established. On the basis of the geotechnical finite difference software FLAC^3D, by using the mechanical analysis and numerical modeling, several schemes with different positions and different buried depths of pipeline were presented in order to carry out a comparative analysis and study. The results show that the pipeline in the front part of the landslide bears the smallest pressure and the maximum stress of pipeline increases with the increase of the buried depth of the pipeline. Therefore, the pipeline with shallow buried depth in the front part of the landslide is best route choice for the pipeline across the landslide, where the pipeline bears the smallest pushing force by the landslide. As a result, the method of choosing optimal position for the pipeline can reduce the geological hazard risk to the maximum extent. This study can provided a scientific basis for the pipeline route selection scheme in underground crossing landslide area of Western China.

With the development of the city and the following need of civil construction, many underground lines in the city are required to be constructed, reconstructed or revived. Horizontal Directional Drilling (HDD) technology has been developing rapidly and applied in many fields all over the world. With the extension of its application fields, the demand for the HDD rig operator is increasing everyday both quantity and quality. Obviously, the operating skill will affect the engineering quality for the HDD engineering directly and even decide its success or failure sometimes. At the same time, due to the HDD engineering is constructed under the ground the trainee cannot see the drilling status with their own eyes so that they cannot understand and find out the relevance between the rig operating and real drilling process systematically and totally. As a result, it is necessary to train enough operators and improve their proficiency for operating the HDD rig, which only can assure the success for the HDD projects. Aimed to solve this problem, this paper combines the three dimension design software with the virtual reality software to develop a virtual train system for the HDD rig operating training based on the theory of the virtual reality technology. The cost of this virtual training system is quite lower with many advantages such as safety and efficiency. Three dimensional models of the HDD rig are built by the PRO/E software, then exported into the virtual reality software VIRTOOLS for the virtual simulation through by the data exchange interface and set relevant operating according to the work process of HDD engineering. The trainee can observe the virtual trenchless rig from various viewing angle and viewing distance and operate the virtual HDD rig for performing kinds of actions in person. Through this kind of training, the operator can master the operating skills quickly and clearly, and avoid the harm to the rig in the initial stage efficiently.

For Lan—Zheng-Chang oil and gas pipeline encountered multiple loess gully or slope, the crossing way of inclined shaft has to be adopted due to the site limiting conditions. First, based on some loess gully slope engineering at Tong-guan in Shaan-xi province, the stability boundary of the gully was determined according to the slope geometry in this paper. Then, the method of three-dimensional numerical simulation was used to discuss the varying laws of the stress, displacement, yield regions of soil mass around the inclined pipeline shaft under the different crossing conditions. The analysis results show that the maximum values of the displacement at vault, side-wall and floor appear in the middle of inclined shaft, and the upward-displacement of the floor is far larger than the subsidence of the vault in the same section, and the value of the down-displacement at the vault is very little in the entrance and the exit of the inclined shaft; the variation of the convergence displacement at middle points of the side-wall, along the direction of the inclined shaft, is very small. During the process of the excavation, the maximum tensile stress appears at the slope shoulder, and the tensile stress zone caused by excavation is very small. After the excavation of the inclined shaft is completed, the maximum shear stress appears at the near of the slope foot, and the maximum shear stress will decrease with the increase of the obliquity of the inclined shaft. The yield region around shaft is mainly caused by shear stress, and concentrated in the section-floor within the 1/4–3/4 range in the axial direction of the inclined shaft. Also the failure region appears at the slope foot. According to the comparative analysis of different schemes, at last, the optimum stable and safety design parameters involved in pipeline crossing the inclined shaft are given. The results provide theoretical basis for the construction safety and reasonable support of the inclined shaft for the oil and gas pipeline.

After intensive research on present oil-gas pipeline application systems, especially, the data structure and functional structure of these systems, we found that the modules of today's oil-gas pipeline application systems are relatively independent. They are usually lack of an effective mechanism for data sharing and exchange ability of modules is not efficiency too. How to solve these problems is this paper's target. In this paper, in view of the coupling module and data sharing, we first rebuilt the original system and provided a new modules organizational chart. We abandoned using business process as a centre to build system's structure. Instead of business process, we putted forward the GIS as the centre and geospatial relation as link to build an expanded business application model. This model made great success in the application of alarm monitoring, the valve open/close analysis. Inspection location, analysis of burst pipes and integration of two-dimensional three-dimensional. It provided theoretical foundation and examples for general application of various types of pipeline in cross oil field business.

The mechanical parameters in construction of Waidiao-Cezi island pipeline crossing by Horizontal Directional Drilling (HDD), including bending radius of pilot holes and pullback load, are studied theoretically. The deficiency of empirical formula is pointed out, the basic factors which influence the HDD project are discussed, and the theoretical formulas are presented. In the meantime, the new concepts of the required minimum and allowed maximum mud pressure are given and the formulas considering the fundamental role of mud in the process of drilling are obtained. As an example, the Waidiao-Cezi island pipeline project crossing by horizontal drilling is analyzed and the theoretical quantitative values of crucial crossing indexes are obtained. According to the analysis and comparison of crucial mechanical parameters, the scheme for the Waidiao-Cezi island pipeline is optimized. The best scheme is confirmed from the three schemes, which is proved to be a success.

The problems such as sticking, tight pull when running casing occurred frequently in the horizontal hole during horizontal directional drilling in sandstone reservoir of a certain Bozhong block. Tests and theoretical analysis reveal that due to the characteristics of high porosity, high permeability, weak cementation and low strength, the sandstone reservoirs are subject to deformation under the effects of earth stress. It is the dominant of the wellbore instability which can be prevented by using proper drilling fluid density. This paper is based on a linear elastic and isotropic mechanics for stress distribution around direction wells and wellbore stability model is developed by comparing the caving pressure and fracture pressure which varied with deviation angle and azimuth. Considered the effect of sandstone viscosity-creep to the wellbore stability simultaneously, based on the experimental results of the creep for sandstone in site, the creep constitutive model and creep parameters is given. A numerical calculation of wellbore shrinkage rate is done by using FLAC3D code. From which the wellbore deformation with time of horizontal well be concluded. The conclusion is that the major cause of wellbore instability in horizontal section is the shear failure of sand stone, the effects of sandstone creep isn't needed to be considered. Synthesized the two factors and fixed the proper drilling fluid density in the horizontal hole. And also make the conclusion that the optimum drilling angle is the direction of the minimal horizontal major stress.

It's well known that the seismic numerical analysis of most buildings use the uniform excitation due to the small geometrical dimensions compared to the wavelength of seismic waves. That means the earthquake ground motion exerted on the simulation model is essentially represented by one point excitation. However, because of the large geometrical dimensions of pipelines and seismic wave propagation effects, the prior assumption is not valid. Different points along the pipeline axis are subjected to different seismic excitations including the change of wave shape, ground motion phase and so on. The dynamic response of the water pipelines to seismic excitation is influenced by many factors, both of the ground conditions, for example the complex ground strata and soil's dynamic constitutive model, and the structural mechanical behaviors, like the concrete's dynamic constitutive model and complex geometrical dimensions of the pipelines. So the 3-D finite element analysis of water pipelines is very complicated because of the complex geometrical shapes, ground conditions and the constitute models. In order to simply the research question we make some assumptions, which includes the fluid(water) here is just considered as a load exerted inside the tunnel linings and the soil liquefaction problem is beyond the scope of this paper. As a matter of fact, the structure of water pipelines is the focus of this paper. A study of underground pipelines subjected to non-uniform seismic excitation using shaking table tests was reported by Meng (2008). The data of the shaking table tests clearly show that when the pipelines is subjected to the non-uniform seismic excitation, its dynamic response is different with the one under uniform excitation and some parts' response is more severe. It can be seen that it is more realistic and worthy that the non- uniform seismic excitation should be considered in the analysis of the seismic responses of the pipelines.

The underground pipeline in liquefaction soil was simplified as a simple beam with the action of elastic force of liquefied soil along it, which its ends were supported by linear elastic springs and restrained by torque springs of non-liquefied soil. Considering the interaction of buried pipeline-soil and fluid-structures, the mode superposition method was used to analyze its natural characteristics. The simulating results showed that the natural frequency of buried pipeline while soil liquefied under the action of seismic loading is proportional conversely to pipe span, fluid flow rate and pressure inside pipeline, axial compression force of pipe section and the density of fluid, but is proportional to elastic constraint coefficient of the end non-liquefied soil, relative elastic coefficient of liquefaction soil and axial tensile force.

Urban water supply system is important infrastructure for citizen's survival, urban safety and development. Wenchuan earthquake damaged many harder-hit cities' water supply pipelines, which was one of the main forms of the damaged water supply system caused by earthquake. On the basis of characters of water supply system and experience from the earthquake relief in Mianzhu City, combining with the characters of Xi'an City where there are long-distance water supply pipelines and locates in seismic zone, we identify that the Heihe River transfer water channels and urban water supply pipeline network are the main vulnerabilities of the seismic risk in Xi'an urban water supply system. The existing groundwater supply systems and some surface water supply systems are important components of urban emergency water supply. Through simulating the Wenchuan earthquake, we identified Xi'an City's temporariness, emergency and restoration programs in water supply after the earthquake, in order to improve the anti-seismic capacity and emergency water supply of urban water supply system in Xi'an City and cities nearby.

According to the Hamilton principle, the differential equation of transverse vibration was derived. Taking earthquake excitation as random wave, applying the method of elasticity time-history analysis, the response of displacement and acceleration at the midpoint were obtained. In the following analysis, with silty clay, fine sand and sandy clay representing soft soil, medium hard soil and hard soil respectively, one can find that with soil becoming harder, transverse displacement decreased continuously. So it could be concluded that under the earthquake excitation, the pipeline's deformation was mainly caused by deformation of foundation. Through comparative analysis, pipe with low intensity and soft foundation can be more easily destroyed than that with high intensity and hard foundation. So the characteristics of foundation had a great influence on pipe destruction. By additional analysis, it can be seen that with increase of liquid velocity in the pipeline caused by earthquake excitation, and leading first to water hammer, then to pipeline destruction, and this case sometimes occurs.

As a kind of shallow buried underground structures, underground utility tunnel's damage under earthquake is mainly due to surface wave like Rayleigh wave. The dynamic response analysis of underground utility tunnel during the passage of Rayleigh wave is thus explored in this paper. Rayleigh wave is first generated using the Approximate Rayleigh Earthquake Wave Method, and is employed to determine equivalent boundary forces applied to the model boundary. Two-dimension free field finite element model is then established to verify the validity of Rayleigh wave input method taking ABAQUS as a platform. Then two-dimension soil-structure interaction finite element model is set up, in which utility tunnel element and soil element are modeled by 4-nodes plane strain element (CPE4). The state nonlinear property of local slippage, open and closure between soil and structure is considered by the master-slave surfaces. Finally, numerical results show that the propagation of Rayleigh wave can be the key factor to trigger the vertical vibration of shallow underground structures. So it's important to consider the Rayleigh wave effect for seismic design of underground utility tunnel.

A method for calculating aseismatic reliability of gathering and transferring pipeline network in large-scale gas field is put forward. Taking the maximal seismic intensity S that might occurred during the design service life in the engineering site of gas gathering and transferring pipeline as seismic loads, taking the fortification intensity I_d that is determined during pipelines design as structure resistance, this paper comes up with random reliability analysis model of pipeline to predict the seismic damage based on both reliable and failure states of pipeline structure. This model is characteristic of seismic destruction. In order to avoid the non-linear programming hard problem caused by the calculation of network reliability, the paper applies breadth first search technology of graph theory and proposes the algorithm for judging the probability of connectivity reliability for the multi-source and multi-terminal network. Combined with Monte Carlo simulation, the algorithm is applied to the aseismatic reliability calculation of super-large gas pipeline network. To give the detailed process of the calculation of seismic reliability for pipeline network under the impact of a serious seism at 7 magnitude, this paper takes a gas field in western China with 37 pipelines, 3 gas gathering stations and 3 industrial users as an example, finds out the corresponding links of aseismatic weakness. The example demonstrates the simplicity, validity and practicability of this method.

This paper presents a three-dimensional numerical simulation method for large-scale seismic response calculation based on a newly built shield tunnel used for water supply in Shanghai. The whole analytical model consists of surrounding soils, shield tunnel segments, bolts, and many other entities. Both the number of nodes and the number of elements exceed one million. This model could consider dynamic hysteretic nonlinear behaviors of soil, contact interface between soil and tunnel, contact interface between bolts and segments; and the contact interfaces between segments. Final calculation has been performed on the Dawning 4000A supercomputer using the finite-element code LS-DYNA 971 MPP. The result provides a global understanding of this water- conveyance shield tunnel under seismic loading and reveals the weak parts. It also provides relevant data and references for the seismic design of tunnel structure in the future.

As an important factor to safe operation of pipelines, seismic faults may cause them to fail with tension rupture or buckling failure. This paper presents a detailed analysis of pipelines using the shell finite element method, considering depth, backfill soil properties and pipeline-soil nonlinear interaction. Conclusions are attained as follows: crossing angle of pipeline and fault is a sensitive factor which easily causes pipeline tensile rupture or buckling failure. Compactness of backfill soil cannot be ignored in theoretical analysis and engineering design. The stress, strain and displacement have a regular distribution, and elliptic phenomenon along pipeline is also needed to be considered.

Pipeline laid across mine area is threatened by potential mining-induced subsidence. To investigate stress distribution of buried pipeline across subsidence-prone area, an analytical method is proposed based on the assumption that pipeline bending curve is described with the ground deformation predicted by Probability Function Integration Method (PFIM). Basic equation of pipeline physical elongation is derived considering of pipe-soil friction and pipe- material nonlinearity. Based on displacement coordination equation, axial strain of pipeline is calculated by iterative solving method, while bending strain by geometry method. Furthermore, two simple equations are derived to evaluate pipeline stress and bending individually. With proposed method, stress and strain distributions of pipeline laid in subsidence area with different crossing angle are predicted and analyzed. The results of pipeline stress and strain by proposed method are close to that of finite element analysis.

In 2009, the American Society for Engineers (ASCE) Report Card for U.S. infrastructure will remain a disappointing grade of "D." They also report that it will now take over $2.2 trillion to alleviate just the needs of existing infrastructure throughout our country. The "Gap" between funding levels and what is needed to maintain current utilities is a staggering $1.1 trillion. With current Federal Program Funding addressing only a small fraction of the nation's need, and a future Recovery & Reinvestment Plan still falling well short of funding this need; municipalities and utility owners will have to find more ways to address renewal of their old and deteriorated assets. The causes of pipeline problems might be from a number of reasons such as corrosion, soil movements, traffic loads, and operational pressures. In most cases, a structurally and hydraulically capable lining that can resist internal and external pressures will overcome these problems. The new hybrid trenchless technology product, Scotchkote 169HB, has been developed to address long-term and short-term loads in water pipes as well as hydraulic and water quality problems. Additionally, it is a breakthrough product to address a number of issues such as abrasion and chemical resistance as well as being economical and an environmentally friendly product. The lining is installed using centrifugal application equipment which results in a rapid return to service of water pipes, saving municipalities millions of dollars. This paper presents an overview of Scotchkote 169HB product and covers its method description, benefits and range of applications.

A smart plug is sent into a pipeline from far end, and accomplishes isolation plugging after reaching specified location. The algorithm for its tracing and positioning is one of critical technologies. Based on the research in transmission rule of low-frequency electromagnetic wave (LFEW) and magnetic dipole, a transmitting/receiving model for LFEW is established; an algorithm for positioning based on bi-peak change rule of LFEW magnetic field amplitude signals is presented. The model analysis and experiments show that good accuracy can be achieved in tracing and positioning the in-pipeline location of a smart plug by taking use of LFEW outside the pipeline.

Suitable pulling force is very important for the safe operation of pipe lining process. But nowadays the recommended values of maximum allowable pulling forces or calculation formulas for PE pipes from different companies or specifications are not so coincide. The paper aimed at finding the correlations and differences of 5 different calculation methods. Through detailed comparison of the calculated maximum allowable pulling forces, the corresponding safety factors are deduced. The study showed that although the forms of the calculation formulas are very different, the results from Wavin, Subline or experience formula are very similar. Comparing with the value from pure pipe strength theory, they all have safety factors of more than 2.2. But the equation recommended by the Specification of China Gas Pipeline Rehabilitation Technology is too conservative, for the safety factor is greater than 3.4.

There are two oil and gas pipelines in ZGBX offshore oilfield. One is oil and water combined pipeline with a DN200 flow line inside a DN350 insulating layer. The other is a gas transmission pipeline with a DN300, which is coated with concrete. With the planning and construction of the development projects of the coastal industrial district in this oilfield, the sea area where the pipelines pass through and the water depth is less than 6m would be occupied, which makes the safe running of the pipelines face a great challenge. This requires that the route of the pipelines must be altered. Based on the comparison and analysis between the non-stop plugging technique with disc and expansive cylinder, the latter was chosen after a comprehensive consideration of various factors. And then an non-stop plugging scheme of the oil and gas pipelines located at two points which are 6.8km apart at the same time was proposed, which includes the following major procedures such as construction preparation, welding under pressure, opening hole on pipe, cutting bleeding balance hole, pipeline plugging, connecting the pipe heads, removing the plugging and so on. The results show that the alteration scheme of the oil and gas pipelines with non-stop plugging technique in ZGBX offshore oil field is correct and reasonable, and the plugging technique with expansive cylinder is safe and reliable. The experience and method of this alteration project can be referred by other similar pipelines.

This paper introduces commonly used methods of underwater cutting, such as flame cutting, plasma arc cutting, high-pressure water jet cutting, explosion cutting, mechanical cutting, ect, and their working principles, characteristics, processing objects, working conditions, technical maturity as well as current status of developments. Using these methods for cutting undersea oil pipeline the subject of this composite material, is very difficult, even if the completion of cutting, efficiency is very low. We developed the use of underwater diamond saw which can be brought to effectively cutting oil pipeline, the technology for underwater cutting operations providing a new method of cutting. At the same time, the composition and working principle of this machine, and the working process of the main components is analyzed. Diamond cutting tools and cutting oil pipeline single-object structure, analysis of the rope saw the work of the main components of the process. By comparative experiments, it has been verified that the machine can effectively cut the oil pipeline, steel materials and reinforced concrete.

The characteristics for submarine oil and gas pipe tapping are analyzed, and a new type of submarine oil and gas pipeline tapping machine (SOGPTM) that can achieve fully automatic cycle is built. The SOGPTM is furnished with all functions of a land-based pipeline tapping machine. As a diver can not monitor the process for a long time when the SOGPTM runs on a submarine pipeline, a hydraulic control system comprising a hydraulic control valve block, a hydraulic cylinder, a synchronous clutch and a hydraulic power is designed. The hydraulic control valve block is fixed on the spindle of the tapping machine body and coordinated with a side benchmark of the tapping machine body; hence the tapping process can be controlled fully automatically through touching valves. Results of experiments indicate that the SOGPTM can fully automatically complete the cycle comprising rapid feeding, slow feeding, rapid retraction, and stopping according to the preset travel without any manual intervention. The SOGPTM solves the problem for fully automatic submarine pipeline tapping.

Culverts importance may not be visible until repair or replacement costs appear, or unfortunately until they collapse. To cope with repair needs of such assets, trenchless technologies are nowadays being used in place of traditional open cut, due in part to their cost effectiveness when traffic disruptions and social costs are considered. In some cases, replacement of a damaged culvert is inevitable; however, the technologies to replace culvert utilizing trenchless methods are limited. Reviewing literature on this topic, field trials and construction case studies have been found with little scientific study regarding feasibility, sequence of installation, safety, cost estimation, material selection and other basic engineering studies. The main objective of this ongoing research is to present a conceptual and developing method to replace culverts using a viable trenchless method. This proposed methodology may enable culvert upsizing by driving a set of horizontally arranged sheet piles over a deteriorated culvert, swallowing it concentrically. Although the proposed alternative currently is not intended to replace culverts in wide roads or freeways, it may become useful when replacing culverts in two way roads under heavy traffic.

The intelligent plug system for high-pressure pipeline is a new isolation system initiated by PSI in the 1990s. Here, the isolating capability of one of its key techniques—locking slider—is analyzed theoretically. It is assumed to unfold the circular contact between the locking slider and the pipeline wall into planar contact, and starts with a 2D contact analysis. The contact deformation between the locking slider's teeth and the inner pipe wall are analyzed using the theory of elasticity mechanics, and the contact force and the penetration depth between the locking slider's teeth and the pipeline wall are calculated using the theory of contact mechanics, and the load limit of the locking slider's teeth is calculated using wedge limit load theory in plastic mechanics, and finally the inner pipeline pressure lockable by the locking slider is calculated. The results show that the plugging technology can lock efficiently as high as 20 MPa of operating pressure in oil and gas pipelines.

Using the technology of lining of HDPE pipe insertion to repair the river-crossed water-supplying pipeline which can have a long service life, as thus, the problem of leaking of pipeline will be solved completely without impact on shipping. And it is concluded that the cost and time using this method can be saved greatly when comparing with the method of replacing with new pipes.

In this paper, a method for inserting a plugging pig into subsea pipeline at right angles and securing it in place within the pipeline, is proposed to replace a damaged section of a submerged pipeline without a significant loss of product from or entry of seawater into the undamaged pipeline. The paper presents in detail the implementation and design issues related to the method and apparatus. The method comprises installing a pair of mechanical tees and gate vales on either side of the damaged section of pipeline, cutting a hole in the pipeline through each mechanical tee, inserting and securing plugging pigs into the pipeline, cutting and removing the damaged section of pipeline. The apparatus include a guide base and a pig-set machine.

The typical methods and new techniques of rehabilitating oil pipelines are introduced in the paper. Both the types and limitations of exterior rehabilitation of oil pipeline are described; and the exterior rehabilitation of oil pipelines includes defect reinforcement of the pipe wall and repair of corrosion protective covering. The defect reinforcement of the pipe wall involves patching, metal clamping, replacing pipe, the epoxy resin filler liner repairing and compound material repairing. Both the technical processes and applicability of the novel interior rehabilitation technology, such as cured-in-place-lining, spray lining, close-fit lining, are commented in detail. The comprehensive applications of these rehabilitation techniques used in oil pipeline are concluded in China, and the new rehabilitation techniques are presented.

Water and wastewater pipes are essential to supporting a healthy and prosperous society. However, most underground pipes are "out of sight, out of mind", and very little attention is paid to inspection and maintenance until they approach the end of their service life. Municipalities all over the world are dealing with continuously deteriorating pipe infrastructure, and tremendous efforts are expended on reactive replacement every year. Conventional reactive replacement and even proactive replacement is not the most cost-effective way to solve the problem. Asset management, with the goal of minimizing life-cycle costs, requires predictive maintenance instead. In Australasia and now in North America, some large metropolitan communities have begun to actively pursue asset management concepts in the water and wastewater sectors. Many experiences and lessons have been learned during the past several years. In this paper, the authors analyze the differences between the dynamics of established markets and emerging markets, which include non-metropolitan communities in North America, and developing countries. In emerging markets, frequently either the resources or the expertise are not available to carry out an asset management program in the same manner as more developed markets. Such differences need to be recognized and considered in the implementation of asset management programs around the world. Merely copying what has worked in more developed markets is unlikely to achieve the desired results in an emerging market.

Because of many engineering projects of the sea-beach industrial district of ZGBX offshore oil and gas field under construction, the routes of two oil and gas pipelines which pass through the district must be deserted and alternated. Considering that their recovery would inevitably obstruct the construction of the industrial district and also be expensive, it is reasonable for the deserted pipelines to stay in the original location. However, there was a large amount of oil and gas remained in the deserted pipelines, which would bring great hidden danger to the large scale construction of the industrial district. Thus the deserted pipelines had to be replaced and cleaned. Then according to the practical situation of the deserted pipelines, a treatment method for them to be replaced with pig and seawater prior to being washed with chemical agents was proposed. Based on the characteristics of the remained crude oil, the safe replacement time was determined. Focus on the cleaning quality, operability and costs, environmental requirements, the technological and economic feasibility of the cleaning methods for seawater, a single chemical agent and three kinds of chemical agents with a pig train were compared and analyzed, and then an optimal cleaning plan for the deserted pipelines was determined. Based on the evaluation of the oil dissolving capability and amount used, the corrosion and environmental pollution for chemical agents, an economical and effective cleaning agent was screened. Then a replacement and cleaning plan for the deserted pipelines was proposed and its realization was very successful. The results show that the safety shutdown time for the deserted oil-gas combined pipeline and crude oil pipeline are 89.8h and 54.9h respectively, and their replacement operation should be finished within 24h; the cleaning method of the single chemical agent is better than the others, and emulsified cleaning effect of the agent AQ-12 is the best; the replacement and cleaning operation was completed by using the designed plan successfully.

The oil and gas pipeline transportation has been developed rapidly in China in recent years. As a result, more and more scheduled and emergent pipeline repair works are required. To carry out hot taps and line stops, hot tapping machines, Lo-profile stop valves, split tees, plugs, and plugging actuators are necessary tools for all of those maintenances. In this paper, the development of oil and gas pipeline hot taps and line stops is introduced. The technical problems and challenges are analyzed according to the development status of hot taps and line stops in China. Finally, the possible solutions are discussed in detail.

This study attempts to investigate the cost of Horizontal Directional Drilling (HDD) and open-cut construction methods for the installation of pressure waterlines in Nairobi, Kenya. The urban areas in developing countries (including Nairobi) attract immigrants from the surrounding rural areas creating very densely populated and congested areas. The streets are very congested with pedestrian and vehicular traffic. The traditional open method in these countries relies more on labor force than equipment. Consequently, open cut causes significant disturbance for lengthy period of time to residents and business. This environment makes the need for trenchless technology paramount. Usually the contractor who is involved in the first trenchless project in the country tries to amortize the cost of the trenchless system through this project. Usually the engineer resorts to trenchless technology only in most difficult situations when open cut cannot be employed and tries to limit the length of the trenchless part only to the difficult portions; as a result, the cost per linear meter increases significantly. The risks are usually high on the first job and the experience with the new technology is low, which also increases the project mark up and cost. Usually the above-cited difficulties stifle the introduction of trenchless technology to these areas. The paper attempts to compare the cost of HDD and open cut for the installation of 1000m long of 30cm in diameter waterlines underneath the busy streets of Nairobi, Kenya a few years after the introduction of HDD to Kenya. The cost analysis indicated that HDD is about 12.5% more expensive than open cut.

Pipeline construction site is the intersecting place of logistics and the stream of people, due to the existence of existing buildings, the place for workers is not often enough, or the operate under the ground and high altitude, so as to easily happen the accidental and safety events. In the view of the characteristics of pipeline engineering construction site, The collection, process, project and application of the safety information manage in the pipeline construction site are discussed using the technology of safety information fixation management in this paper. Solving the safety problems in pipeline construction using the safety information fixation management technology is presented. With the suitable site management board, the workers can understand the requirements and intentions of managers through visual information. This management mode can prompt the operator's self-management and self-control. The promotion of the technology of safety information fixation management in the pipeline construction site will accelerate the standardization of safety management in the construction and installation company.

Selecting most suitable methods for rehabilitation of water main networks has become a challenging task; considering the wide range of emerging trenchless methods. Developing decision support methods is expected to assist municipalities in North America and elsewhere in carrying out the selection process effectively. This paper introduces a new concept for choosing cost effective rehabilitation methods accounting for cost and duration of each rehabilitation method being considered along with its impact on environment using Multi-Objective evaluation methodology (MOM). The first objective, cost of rehabilitation, is calculated considering a number of cost elements including social cost. Social cost, in the developed methodology accounts for cleaning costs, loss of sales tax, number of impacted vehicles and pedestrians, etc. The second objective is the duration of the rehabilitation method under consideration. The environmental impact is considered as the third objective. It is modeled considering several factors using the Analytical Hierarchy Process (AHP). In order to demonstrate the essential features, a hypothetical example has been developed to test the model robustness. Results show that a cost effective method can be selected by combining cost, duration, and impact on environment.

During shield tunneling, as segments exit from the shield, an annular void occurs between the shield tail inner side and the lining outer side. The void must be back-filled with grout to provide a compact fill and avoid ground surface subsidence. However, flotation of the tunnel within the fluid grout and soft soil can also cause tunnel uplift; this paper studies the relationship between early strength of single grout subsidence and Shanghai Yangtze River tunnel stability upon shield tunneling. Influence of the rate of tunneling on tunnel stability against uplift is also studied; a longitudinal and transverse calculation model is established to investigate tunnel uplift in relation to grout strength increase. From the analysis, safety criteria for the structural lining are verified. Finally, relevant construction technological measures are suggested against tunnel uplift for shield tunneling.

This paper analyses the influencing factors based on a trial section of pipe-jacking project in the city of Langfang, which is close to Beijing. The relative weight of each influencing factors is obtained by the comparison between the field measured and theoretical calculation pipe-jacking force. The authors had colligated all aspects of the influencing factors and proposed improved formula for calculating pipe-jacking force. The improved formula can predict more accurate jacking force and provide more reliable theoretical basis for slurry balance pipe-jacking project design and more accurate data for the design of subsidiary facilities (such as reception shaft and exit shaft) of pipe-jacking method.

With the engineering practice of a Sewage Interception Project, the essential technical measures on the construction of pipe jacking during long-distance were discussed, which mainly include the construction of the jacking shaft, the jacking pipes breakthrough technique, correction and guidance in construction, partial air pressure balance method when jacking through drift sands or flow plastic soil, drag-reduction using thixotropic slurry, arrangement of the pipe section with different types of grouting holes, soil reinforcement using cement slurry to replace thixotropic slurry after the completion of the jacking and interjack station techniques in long-distance pipe jacking. After being jacked through deviation of the jacking pipe axis was within 60mm and deviation of the elevation was within 50mm; soil movement had no significant effect on the pipelines nearby; construction proceeded fast as earthwork was effectively reduced; damage to environment was limited to minimum because of low noise in underground construction and the concentrated emission of soil and slurry. The result showed that good economic and social benefit was achievable using the above-mentioned technical measures in long-distance pipe jacking.

Pipeline conveyance system is one of the key links for continuous pipe lying by pipe laying vessel. Pipeline conveyance process is discomposed, the characteristics in load on the pipeline and motion for each link are analyzed; kinetic analysis for the whole conveyance process is conducted, a mathematical model is established; criteria for judging the coordination in motion time between links for the pipeline so as to guarantee continuous pipe laying are presented. Finally a calculation program is written, the results of which can guide the design of pipeline conveyance system.

Combine shanghai momentous project-Qingcaosha water head area project, the engineering feasibility of parallel large caliber pipe-jacking is demonstrated, the design parameter such as horizontal spacing, earth covering, steel pipe thickness are confirmed.

The strength-oriented is a key parameter that decides the accuracy of Horizontal Directional Drilling track. The dominant impacting factors of the strength-oriented are comprehensively analyzed in this paper for designing oriented drilling tracks. A computing model of strength-oriented is deduced and built based on the deformation analytical method of mechanics of the bar materials, and the model is tested and verified in actual construction. A three-dimensional track design system is developed based on this model.

A Buried Duct/Pipeline Network (BDN) is presently under development representing an integrated system to facilitate future upgrades of buried communications (telephone, CATV) and/or power lines. The new pipeline network, being developed with the support and encouragement of the U.S. Department of Transportation (US DOT), represents improved practices relative to current direct-buried construction procedures, which do not otherwise allow for future upgrades or replacement of initially installed utility cables. The original intent was that the BDN would be originally installed using open-cut trenching construction, by which the conduits would be placed in the trench, at a specified separation, and the associated handholes readily laid on top of the conduits. Recent field trials, however, have demonstrated the feasibility of using mini-HDD machines, in an innovative manner, to cost-effectively install the BDN in established areas in which open cut trenching methods would not be practical.

To prevent the problems from occurring in the preheating installation of directly buried heating pipes with large diameter, high temperature and pressure, the present paper analyses constraints of the least-cost for preheating installation of large-diameter directly buried pipes by applying the nonlinear programming theory and establishing the objective function with the aim of pursuing the preheating installation's least-cost. Taking medium steel pipe wall thickness and preheating temperature as variables, this objective function works out the preheating temperature and wall thickness of the least-cost preheating installation by using Matlab Optimization Toolbox. The results of which show that the higher the pressure is, the thicker the wall thickness and the lower the preheating temperature is, that the best preheating temperature is equal to the lowest preheating temperature limit. In addition, the highest preheating temperature limit is allowed to rise with the increasing of pipe wall thickness, but the increment of temperature is much lower than the decreasing amount of the lowest preheating temperature limit. Research also indicates that increasing the pipe wall thickness is effective in avoiding local buckling, whereas, decreasing the preheating installation temperature is more effective than it in preventing the cooling abruption. Such conclusions are of important guidance significance in several aspects such as reducing installation cost of large-diameter heating pipes, saving preheating energy consumption, shortening construction period, improving pipeline security and so on.

Currently, horizontal directional drilling, impact spear, horizontal spiral drilling, rammer and other technologies are used for the underground trenchless laying of small-diameter and middle-diameter pipelines. At first, after comparing the working method of puncturing mud dragon robot with impact spear which tracks can be controlled. The pneumatic impact mechanism of puncturing mud dragon robot was designed and deduced its mathematic model and used the numerical value method to solve its dynamical process; Second, analyzed the influence between the main parameters such as piston displacements at different position, piston mass, system pressure and exports those are impact energy, impact frequency, impact velocity and returning velocity, and pointed out their connection and restrict. Third, the optimize design on the pneumatic impact mechanism was put up based on the shortest of piston journey and get the optimize design parameters. In the end, the performance tests on impact force, impact frequency and so on for the impact mechanism were done, and validated its rationality.

According to mechanical extrusion soil method and thermal extrusion soil method along with engineering practice or experimental analysis, it is evaluated all kinds of soil body including applicative condition, character and technical advantage and so on. Under different extrusion soil power, different configuration form and parameter requirement, numerical simulation and experiment indicate that roll drilling bit combination with libration is an credible extrusion soil process. In order to hurdle "efficiency of pile," different configuration form and parameter should be considered. High pressure pulse technology is a foreground process which is an effective "enlarge stake hole" presently.

Local buckling may happen when directly buried pipes with large diameter, high temperature and pressure adopt cold installation. When preheated installation is operated in cold water or during the cooling process, it will lead to serious accidents such as pipeline rupture, compensator fracture and so on. Based upon the analyzing of conditions such as pipeline pressure resistance, radial stability, local buckling and pipeline tensile fracture, the study worked out minimum wall thickness and the function formula of lowest and highest temperature limitation for preheating under idealized conditions. The correction coefficient of calculation results is proposed with reference to the influence of the possible stress effect generated in construction, pipe characteristics and its defects. An important conclusion is drawn: the preheating temperature is not only related to the heating medium temperature variation, but also related to heating medium pressure, pipeline wall thickness, pipe bedding properties, construction quality, and pipe characteristics, etc. The minimum wall thickness and preheating temperature range corresponding to the wall thickness can be calculated when system temperature and pressure are defined. When preheating temperature is controlled in the temperature range, the heating-supply pipeline is in safe condition; in the meanwhile, a great deal of steel can be saved and preheating consumption can be reduced notably.

In order to provide a reference for other designs and construction of deep foundation pit project of shield receiving shaft with similar engineering geological conditions, taking the shield receiving shaft of the river-crossing tunnel in Wuhan with maximum foundation pit depth of 21.555m for instance, the characteristics of design and construction of the foundation pit with the bracing are presented through analyzing the formation and the engineering geological characteristics in the first Yangtze River's Terrace. Subsequently, the safety and stability of excavating are evaluated by calculating internal force and displacement of the bracing in different working conditions. The results indicate that soils of the first terrace of Yangtze River are of low strength, high compressibility, unfavorable self-stabilization, complicated aquifer and abundant groundwater, based on which the conclusion that the key points in construction are construction of bracing and treatment of aquifer can be obtained. The construction for foundation pit of shield receiving shaft was operated according to the engineering characteristics of the sort of formation, and it is effective to adopt the methods of diaphragm walls with steel shotcrete and dewatering with medium-deep wells.

The availability of high quality PE100 polyethylene pipe in China has lead to a rapid growth in the use of trenchless technology for the renovation and installation of Municipal pipelines. This paper describes a number of examples of trenchless technology projects using PE pipe including the long distance directional drilling for a water pipeline installation and several projects where PE pipe has been used to renovate old concrete and iron pipelines. The importance of polyethylene pipe quality, characteristics and specification will be highlighted together with the need to maintain high quality jointing and engineering practices for successful trenchless projects.

In northern Shaanxi one segment of West-East Gas Transmission, a large number of loess landslide after the rain has caused serious threat to the pipeline. In this paper, based on freeze-dried samples and SEM test loess micro-structural changes have been analyzed, then combination of shear strength tests the reason of landslide have been explained successfully. The results showed that: (1) loess sample could be sufficiency dry and structure unchanged by the freeze-dried method, and the precision requirement of micro-structural test could be meet. (2) Compared between before and after loess Collapsible test the cement changed from Saturated to flake, pore size become smaller and distribution of pore become more and more oriented (3) After the collapsibility, loess structure damage and pore orientation lead to shear strength of loess sharply decreased, which was the reason of the occurrence of landslides.

The geological environment of the section from Dalian to Yingkou in Dalian LNG (Liquefied Natural Gas) project is much more complex than that of others. Various geological hazards developed and caused severe threat to the construction of pipeline projects and safety operation. Closer analysis to the patterns of the geological hazard, development characteristics, forming conditions and influencing factors is given based on the data of geological survey. The geological hazard assessment indexes and their classification criterion are presented through the degree of geological activities in history and the development tendency in the future. Furthermore, comprehensive assessment of geological hazard in construction area is made by using Fuzzy-AHP approach. The result of comprehensive assessment accords with the actual situation, so it provides the basis for pipeline's programming and for prevention and control of geological hazards during the construction process.

Geohazard is one of the most serious threats to shallow buried pipeline. Based on the date of investigation, risk assessment and risk ranking are most important tasks of pipeline geohazard risk management. At the phase of investigation, qualitative assessment technology or quantitative assessment technology can't offer a risk ranking for thousands of geohazards. Semi-quantitative assessment technology can calculate the relative risk based on the simple date of investigation, and risk ranking can be made. According to the definition of the risk, a risk assessment model was established for pipeline geohazard. Analyze the major factors affecting the geohazard risk and index system of the geohazard susceptibility assessment was established. Meanwhile, it also considers the influences of the different index and gives the value of weighting factor. The possible state of each index on site is analyzed, and the risk is estimated which are expressed by values. The semi-quantitative assessment systems are established for the primary pipeline geohazards, such as landslide, rockfall, debris flow, mining ground subsidence, hydrotechnical hazards and loess collapse. The classification standards of the risk is established in accordance with the situation of geohazard prevention.

In the process of delivering oil, for the delivering process of gathering pipeline is complicated, the service life of pipeline and the quality of oil delivered will be highly influenced by pipeline corrosion caused by many reasons. Even the environment will be polluted by leak, especially the severe corrosion (caused by the water in oil) of the inside wall in the gathering pipeline. The article focuses of the diagnosis of the corrosion mechanism of the gathering pipeline and the affecting factors, including the sorts of corrosion and its corresponding protective measures. The author provides the method of predicting the remaining service life of corrosive gas-oil pipeline based on the gray theory model. The prediction of the remaining service life of corrosive pipeline including: determination of maximum permissible corrosive depth; the prediction of corrosion rate; and the prediction of remaining service life. This method provides a scientific foundation for the examination cycle of the corrosion of gas-oil pipeline.

This paper was concerned with anti-corrosion property of epoxy coating. By use of autoclave, the epoxy coatings were exposed to medium including 1.8g/L NaCl and CO₂ with partial pressure of 1.8 MPa, and temperature was 30 °C, 60 °C and 90 °C. The characteristics of coating before and after corrosion were investigated by use of EIS, SEM and EDS. Results indicated that compared to 5% NaCl medium, failure of the coating increased much more due to existence of CO₂. In addition, temperature of the medium played an important role for the failure of the coating. Appearance of the epoxy coating didn't change evidently, but the metal had been corroded locally at 30 °C. At 60 ° and 90 °, the coating blustered and departed from the metal, the corrosion medium clustered beneath the coating, and there were much corrosion product. These phenomena indicated that the epoxy coating failed quickly with increasing of the temperature.

In view of severe corrosion of welding joint of pipeline steel used for oil transportation, the welding joints of X65 pipeline steel formed by two different welding processes, plasma arc welding (PAW) and TIG welding used for backing welding and MIG welding for subsequent filling welding, were compared in terms of the microstructure, the hardness and the corrosion resistance with the welding joints formed by submerged arc welding(SAW). The results show that the microstructure of the PAW joint is finer and more uniform than those made by the other welding methods; The hardness of all the three kinds of welding joints can meet the NACE criteria. The results acquired from the electrochemical experiment and the test of sulfide induced stress corrosion cracking (SSCC) show that the PAW joint has the best corrosion resistance.

It is the most effective method for coating to prevent internal corrosion of pipeline. In order to investigate property change of anti-corrosion coating during its service, this paper was mainly concerned with failure of epoxy coating in different temperature and medium. And the failure process was inspected by electrical impendency spectrum and microscope. The results indicated that temperature and acid solution had large effect on coating. The failure process accelerated with decreasing of PH and increasing of temperature. Double capacity increased and resistant decreased rapidly with time. Furthermore, the temperature played much more effect on coating than PH. The failure mechanism of coating didn't change with increasing of temperature.

Urban flow pipe system is one of the important city foundational infrastructures, and that pipeline is the key tache of water supply. It aims at the water supply safety problem more and more prominent, by the angle of relationship between pipeline invalidation and time, separately by time reliance, stabilization and invariability, being independent of time with pipeline erosion, pipeline bug and pipeline breakage failure causes and so on, and in which carries through material sorts. It builds pipeline failure risk control decision-making tree, and then comes out with scientific and effective control method and prevention and cure measures of pipeline failure risk.

Due to the effects of physics, chemistry, electrochemistry and microbiology, growth-ring is formed in water pipelines during operation all the year round. It is an irregular ring that composed of sediments, corrosion, scales and biofilm. There is an annular laminar layer along pipe wall at low flow velocity. Caused by a sharp increase of flow velocity, the damage of the laminar layer will scour the growth-ring. Moreover, sediments, corrosion, scales and biofilm can be readily scoured into water and then lead to deterioration of water quality. Growth-ring not only influences water quality, but also reduces ability of transportation and water pressure, because of the reduction of flow rate and runoff, increasing the resistance coefficient and thickening the growth-ring. Although previous pipe cleaning methods can effectively remove the growth-ring, keep pipes clean, reduce secondary pollution and prolong pipe life, there are many shortages of these methods. Hence the application of these methods is limited. In this study, a new kind of pipe cleaning method with gas-water pulse and water-hummer was introduced. It is a highly efficient, water-saving and low-cost method for growth-ring removal.

Many geographical information systems (GIS) have built to manage the nodes or pipes information of Water Distribution Systems (WDS) in cities recently. However, there are a few known examples of the integrative information management system for the WDS analysis including GIS, customers' information, hydraulic characteristic of equipments, operation and maintenance data and Supervisory Control and Data Acquisition (SCADA) information. To building a database structure, possessing the characteristics of perfect structure, sharing, less redundancy and security, is the core of the information management which is modeled by the theory of relational database, and the database structure is created by the method of the Entity-Relationship analysis which divided the pipelines, nodes, attachments, equipments of WDS into two kinds of entities, nodes and links. The model can be applied on any relational database management software, and be ready for updating the information of WDS, describing the current state, designing water networks, simulating hydraulic state or water quality of the extended period and optimizing the operation for WDS analysis.

X80 steel has been proposed to be used as materials of spiral welded pipeline in the Line 2 of the West-to-East Gas Pipeline Project in China. It is known the welding joint is the most hazardous site due to the attack of corrosive media. However, few reports on the corrosion of welded X80 steel are found. In order to make optimal program of trenchless corrosion monitoring technique and anti-corrosive measure, weight loss, electrochemical test, metallographic observation and optical microscopic analysis were adapted to investigate on the internal corrosion in NACE solution containing sulfide hydrogen and in groundwater containing carbon dioxide of welded X80 steel sampled from the pipeline in the present paper. At temperature of 40 °C, the same corrosion resistance ranking in the two cases is base metal (BM) > weld metal (WM) > heat-affected Zone (HAZ). The corrosion behaviors were discussed on the basis of the metallurgical structures and the corrosion electrochemical mechanisms.

The corrosion identification of buried oil and gas pipeline wall is studied by the way of observing strain value of pipeline ektexine under work pressure. The least square method is applied for establishing geometric parameter identification model of pipeline wall. Based on wall radius and eccentricity which are defined as design variables, the optimization of finite element method is also applied for inverse analysis. The size and location of corrosive area can be identified by strain change of pipeline ektexine. It is verified that this method is effective, precise and valuable by numerical simulation.

Considering that it is simplicity to evaluate the external corrosion condition with single factor, the key factors affecting comprehensive evaluation for external corrosion are ascertained based on analyzing the effect of various factors, and which contain soil corrosiveness, stray current, external covering state, cathodic protection effect and pipe corrosion thinning. The model of weight distribution of key factors is established, and the fuzzy comprehensive evaluation system of external corrosion for buried pipeline is established with analytical hierarchy process (AHP) method. The field applications show the method is practicable and reliable.

The role of sulfide ion on corrosion performance of pipeline steel (Q235B) is studied in simulated inner-seeper environment by electrochemical methods. Results show that the corrosion of Q235B steel is promoted with low sulfide ion concentration. The Q235B steel has the maximum corrosion rate when the concentration of sulfide ion is 20mg/L, but passivation effect is found with the time prolongation. High concentration of sulfide ion has obvious corrosion inhibition effect to Q235B steel. The concentration of sulfide ion greatly affects the surface morphology of Q235B steel. The pitting corrosion is more obvious with low sulfide ion concentration. General corrosion happens with the increase of sulfide ion concentration, while the compact passive Fe3S4 corrosion product film is found with higher sulfide ion concentration, which has certain protection on Q235B steel matrix.

Cathodic protection and coating are two necessary measures complementary to each other for corrosion control of long distant oil/gas steel pipeline (Hu, 2004, and Yang, 2006). It is usually of difficulty in finding the unconscious/vicious damage of pipe coating in time. For a buried pipeline, this damage is more covert. Native and foreign corrosion control codes for buried steel pipeline (SY/T 0036, 2000, and DNV-RP-F106, 2006) stipulate the cathodic protection parameters of test stations and cathodic protection stations must be measured regularly. It is a manpower work mostly, time-consuming and hard sledding, with poor reliability and real-time, so we can't know the current conditions of pipeline coating in time. Remote monitoring technology for cathodic protection develops rapidly in recent years, profiting for the development of electronic information technology. In America, After Zero Technology Corporation and Institute of gas technology developed cathodic protection remote monitoring system. In 2004, America's CC Technology System invented Automated cathodic protection monitor and control system. And Fujian Institute of Research on Structure of Matter, and South China Sea Institute of Oceanography, Chinese Academy of Sciences, as well as Dalian University of Technology developed in succession cathodic protection monitoring system.

Most of long distance steel pipelines are buried underground, and take impressed current cathodic protection as one of their main ways to prevent corrosion (Parker, 1998 and DNV-RP-F106, 2006). The pipelines are often covered with the coating. When the coating was damaged by the third party such as tapping for stealing oil, transition resistance will decrease at the position of damaged coating, and then potential and current along pipeline will change. This paper purposes to seek a method to find the position of damaged coating by utilizing the values of currents and potentials at the ends of the pipeline protected by a single cathodic protection station. Indicating the extent of the damage, and the grounding resistance at the position will also be studied. It frequently happens both at home and abroad that people steal oil by tapping on an oil pipeline (Chen, 2002 and Guo, 2006). It not only brings oil loss to the pipeline Company, but also seriously threatens the safety of the pipelines and the environment. Consequently, it is an important for oil pipelines to find out when and where the damage of coating occurs. The coating will be inevitably damaged in the process of tapping for stealing oil; therefore, measuring the potentials and currents at the both ends of the protected pipeline can be used for detection of stealing oil by tapping.

In view of the CO₂/H₂S corrosion of buried oil pipelines, the corrosion mechanisms of pipelines are investigated and some related influencing factors are analyzed. Taking Q235 steel for the buried oil pipelines of an oilfield as the case, the CO₂/H₂S corrosion behavior of Q235 steel is tested by using corrosion testing device and SEM; and the influence of different factors, such as temperature, Cl ion concentration, CO₂ partial pressure, H₂S partial pressure, and pH value, is studied in the simulated buried pipeline environment by using orthogonal experimental design method. On this basis, the corresponding CO₂/H₂S corrosion rate prediction model of pipelines is established by using Grey-Neural Network Theory, which has high prediction accuracy and credibility by an example of verification. According to the results, the protective measures are presented by adopting the Cathodic Protection Technology and Chemical Anti-corrosion Technology etc, which has certain guidance for the extension of pipeline-life and improving the economic benefits of pipelines.

The positioning of damaged points in outer anticorrosion coating of underground pipelines and informational management of these damaged points is significant for pipelines risk management. It plays an important role in security management of pipelines. The functions, such as positioning as well as informational management ensure the safe operation of pipeline. This paper firstly introduced the basic principles of the CORS and function module of embedded GIS, and then given the example of how to use methods such as embedded GIS, CORS, as well as geophysical to integrate coordinates collected into attribute edited. According to inquire the figure of insulation resistance of coating and the number of damaged points in a given distance, it evaluated condition of Anti-corrosion layer. With the help of embedded GIS visiting database, which 3G network keep the database update, it can evaluate present condition of Anti-corrosion layer. It will become more efficient and effective to use embedded GIS management as well as CORS positioning technology in the inspection of outer anticorrosion coating of underground pipelines. It also can provide basis for anticorrosion maintenance.

The output current of poteniostat in Renqiu station was maintained very high for a period of time. In view of this problem, different methods are applied in this paper, such as PCM current in pipeline to the in-site testing and evaluation. Ultimately the resean of the problem was identified.

Pipeline External Corrosion Direct Assessment (ECDA) methodology published by NACE is intended to improve safety by assessing and reducing the impact of external corrosion on pipeline integrity. There are many kinds of inspection tools to support this methodology. AC current attenuation surveys are typically used to assess coating quality and to detect the discrete coating anomalies. Also, there are many tools that can be selected during indirect assessment step, such as C-Scan or PCM, which are based on AC attenuation surveys, the main difference between any two tools may be various frequencies of AC signal from their transmitter. Although the current in pipelines are easily detected by receivers of PCM or C-Scan, the relationship between coating quality and the current is highly difficult to be found. According to the electrical transmission line theory, Rg can be defined as the appropriate parameter that can indicate condition of coatings. However, the holiday density of coating was not considered in this theory. In this paper, Y (the AC attenuation rate) and holiday densities are considered as the effective parameters to assess the external corrosion of the pipeline with a coating. The evaluation methodology of pipeline coatings based on ac current attenuation survey is developed in this paper. Using this approach, Rg Value, Y value and holiday density play appropriate role on the assessment. Some new modules are presented in this approach, including current distributaries module, holiday module, and intelligent critical curve of AC attenuation.

With tetra butyl titanate and stannic chloride as precursors and n-propanol as solvent [Ti:Sn=100:10], nanometer-sized TiO₂-SnO₂ DSA electrodes were prepared by Sol-Gel method. The micrograph and structure of the electrode surface and the element composition of surface layers were analyzed by SEM, XRD and EDX. The O₂ evolution potential was observed by cyclic voltammetry. The relationship between the electro-catalytic characteristics and the electrode structure was analyzed. In this paper, oily wastewater from petroleum refinery was treated by self-prepared electrodes. Water quality of the treated oily wastewater achieved national discharge standard I, and met the production requirement. The influence of critical parameters, such as voltage, pH value, electrolysis time and electrode spacing, on the oil content and COD removal rate was studied in the experiment. The experimental results indicate that when the voltage is 17V, pH value is 3, the electrode spacing is 1.25cm, and the electrolysis time is 60min, the oil content and COD of the oily wastewater is 5.97mg/L and 28.26mg/L, namely the removal rate is 96.75% and 94.63%, respectively.

To solve the pollution problem caused by separate storm sewer system dry weather flows, Shanghai Water Authority has set intercepting facilities in most storm water pump stations to intercept dry weather flows which induced by illicit connection & discharges. In this paper, two typical separate storm systems in Pudong New District are chosen to investigate water quality of dry weather flow and wet weather discharge before and after interceptor facilities been put into use to evaluate the intercepting effect. The study results show that: after intercepting, in both dry and wet weather flow, COD, SS, TP concentrations are significantly higher than those before, the change of NH₄⁺-N concentrations are influenced by the TN concentrations in illicit inflows. The impact extent of dry weather flows interception to wet weather discharge quality is proportional to the extent of illicit discharge to separate storm system, and also affected by rainfall intensity, rainfall amount and the flow rate of discharge. The quality of wet weather discharge was seriously deteriorated especially in the case of heavy rains, which brought severe pollution load to the receiving body. Therefore, just intercepting the dry weather flows is not able to solve the pollution problem caused by illicit connection & discharge of separate storm sewer system.

This paper analyzes the current situation of environment and energy in Lanzhou. There is no doubt that the development of Lanzhou will play a significant role in the implementation of the western development, but The ecological environment is fragile and air pollution in Lanzhou is still serious, especilly, in winter dust or smoke coming from burning coal will cause further environmental degradation. These incidents have not only jeopardized our public health, but have also inflicted considerable loss to our economy so further implementing the strategy of sustainable development and broadening sources of income and reducing expenditure in Lanzhou are imperative under the situation, There is also potential and utilization for exploiting heat in urban drainage pipe network. This paper also presents the economics and environmental protection value of three systems, including urban untreated sewage source heat pump, gas direct-fired heat pump, and coal boiler plus electric water chiller. The results indicate that the economic and environmental protection value of the urban untreated sewage source heat pump is the best; on the other hand, it saved lots of primary energy, so it has a high energy value.

Slurry shield tunneling has been successfully applied worldwide in recent years due to its virtues However, in a complicated environment, the prediction and control of ground surface deformation and displacement due to large slurry shield excavation remain important problems to be solved. This paper presents the analytical formulation for ground surface deformation and displacement induced by tunnel excavation based on a stochastic medium model. An optimization theory of Powell's Conjugation method was employed for the back-analysis prediction of settlement in this model. Based on ultra-large slurry shield tunneling in the building zone of Shanghai Yangtze river project, the ground surface movement induced by uplink tunneling as well as cumulative movement of uplink and downlink tunneling was accurately predicted using the associated program. Recommended procedures for tunneling in a building zone are also presented. The case study verifies the validity and reliability of the theoretical approach and can be serve as a reference for other similar engineering projects.

As toxic industrial waste water or other liquids is discharging or transporting by pipeline, due to pipeline corrosion damage or other external force action, the leaking liquid can pollute the soil, groundwater or the surrounding environment to a certain extent. The possible leakage forms and characteristics (geometrical features, the source concentration, etc.) of pollution sources in leakage zone are discussed and analyzed in this paper. In order to analyze the changing rule of the concentration of poisonous substances and the range of dispersion halo after the leakage in time and space, the planar seepage flow equation is set up and typical medium geotechnical parameters is selected for computer simulation to pipeline leakage pollution. The simulated results coincide with the reflected general law of pipeline leakage detection. This research achievement can provide a related scientific basis to the current pipeline leakage detection, the risk assessment of pipe leakage and the groundwater environmental assessment.

Yulin-Jinan gas transmission pipeline project is another important gas pipeline project constructed by China Petroleum & Chemical Corporation, following Sichuan to Eastern gas transmission pipeline project, which is also a National "Eleventh Five-Year" key project. The number of construction contractor who took part in the Yulin-Jinan natural gas pipeline construction projects are more than 80, including exploration, blasting, the laying of pipelines, corrosion prevention, flaw detection and so on. Because individual contractor's HSE concept are different greatly, HSE education and training are heavy, the key content of the site safety monitoring is more, structure of project management organization is complex, construction period is long, the task of coordination with the local government and people is difficult and so on. So HSE management of the construction period contractor is the difficulty and focus of the project construction safety environmental protection. Therefore, the HSE management of contractors will directly affect the company's integrated HSE performance. This paper comparing the management system standards with project actuality and contractors' actual condition, sets down a set of practical and operable management procedures and requirements, which has a significance for standardizing contractor management and improving enterprise HSE performance.

Now, all over the world, geologic hazards have became primary threatens to the natural gas pipelines. Almost all the long-distance gas pipelines pass though diversiform geologic circumstances and encounter many sorts of geologic hazards such as sink, slope movement, mud/landslide and seismic threat etc. Because of the greatly sudden and destructive characters, the consequences of gas pipeline failure resulted from the geologic hazards are always grievous. Thus, it is an important task to predict and decrease the loss of the failure. Risk assessment can offer effective methods to managers to make preferable decisions to decrease the pipelines' risk level due to geologic hazards. The mechanisms of threatens of geologic hazards to the gas pipeline are analyzed. Based on this, risk factors of natural gas pipeline due to geologic hazards are recognized, including the failure likelihood and failure consequences, and the five-grade factor system is set up. Further more, the geologic hazard risk assessment model is developed. The likelihood model is developed to account for factors that cause each threat. The consequence model is developed based on statistical analysis, industry practice, and engineering judgment (input from subject matter experts (SME's)).

Remaining life of tunnel can be predicted and optimum maintenance plan can be determined through Reliability estimation of in-service tunnel shield capacity. This article illustrates time-varying model of capacity parameters and modified methods of it and then builds a random process performance function of bearing capacity. Based on this, the methods calculating reliability of both planning and in-service tunnels are analyzed. It can be drawn from the analysis that the reliability of in-service tunnels will be better than planning tunnels at the same situation.

Municipal pipeline construction project plays a very important role in the city. The quality of the construction is contacted with urban development and people's daily life. Beginning with the pipeline safety management of construction, the article discusses the safety evaluation system, with the combination of considering relevant designs of project, engineering conditions and construction factors. It aims to provide a reliable methods and evidence for the safety evaluation of the pipeline project.

The failure and leakage of the oilfield natural gas pipeline may lead to many serious sequences, such as the severe casualties and property losses. This paper analyzes the characteristics of the leakage of natural gas pipeline and the subsequent explosion accident of vapor cloud, adopts the TNT equivalent method to calculate the results of vapor cloud explosion of certain natural gas pipeline in Daqing Oilfield, and gets the relationship between the area of harm zone and leakage time as well as the harm radius corresponding to the different leakage time and area of discharge opening. In addition, it discusses the calculation results and gives the suggestions to reduce the loss resulting from the pipeline disaster.

Oil and gas pipeline transportation plays an important role in the national economy, but there are many accidents in gas output process such as pipeline perforation burst and the trust of pipeline floods. In order to ensure the safe operation of oil pipeline and reduce the loss after the accident happened, this paper established an oil and gas pipeline safety platform based on GIS technology. The purpose of this platform is to provide an accurate, real-time and effective service. The platform organizes and manages complex data of pipeline based on large-scale GIS-based spatial database. It uses WEBGIS publishing technology as well as Ajax technology to monitor the state of pipelines online. It provides a real-time monitor to report dynamic changing of pipeline operation. With GIS spatial analysis, it can accurately report the location of pipeline leaks. It also establish the explosion accident analysis of the logic control network model, a timely and expeditious manner to find the valve should be closed, and finally, it analysis the scope of the effects of the accident using decision-making pre-warning knowledge database. After running the experimental platform, it provides a higher degree of information security. And safe management will get stronger guaranty in oil output process. It also provides data support for supervising pipelines engineering.

GO method is an effective analysis means of system reliability. First, the function and purpose of GO method is expatiated; in succession, the technique and process is presented that using GO method to analyze the reliability of length oil and gas pipeline under third-party damage; finally, the exercise of GO method is illustrated.

A new type of safety valve that has been authorized will be mainly used in high pressure pipelines or pressure vessels in the fields of petroleum, chemistry, heating and others. In the purpose of overcoming some design flaws of traditional safety valve, it has improved in technology, making that all kinds of high-pressure medium will be safely discharged or imported into the appropriate processing system. It can prevent effectively the staff and environment from the accidental spatter or leakage from loose screw connection caused by the larger impact. To illustrate the fine nature of this improvement, we analyze the different structure characteristics between traditional safety valve and this new type of safety valve and have a CFD simulation.

The purpose of this paper is to discuss the mechanical properties of piping materials and the piping database design. The mechanical properties of piping materials produced by companies are very useful information during the design and safety management of oil and gas pipeline. The primary mechanical properties which meet the international or domestic standards are slightly different. Sometimes the difference of yield strength can reach up to dozens of mega Pascal. The 376 groups of X70 grade pipeline steel produced by An Gang Steel Company (ANSTEEL) and 139 groups produced by Pohang Iron and Steel Co. Ltd (POSCO) were adopted in order to acquire the statistics of mechanical properties. The results indicate the average yield strength of ANSTEEL X70 steel is 1.12 times Specified Minimum Yield Strength (SMYS) and POSCO 1.18 times SMYS respectively. According to the data characters, the management database of the mechanical properties was designed based on Computer/Server structure. The remote database query system was applied based on Brower/Server structure.

During exploitation of deep drilling, the problem of drill string failure is very serious at present. The strong vibration of drill string is one of the main reasons that causes drill string fatigue failure with the length increase of drill string. In this paper, the some models about the axial vibration, the lateral vibration and the torsional vibration of drill string are set up in deep wells for the actual situation and these models are calculated with the ANSYS software. The rules of drill string vibration are obtained by the analysis on the vibration models. All sorts of resonance frequency of drill string are obtained and the fatigue state along the drill string can be shown with the animate shape and vector plot. They prove the practicability of the ANSYS software and provided the theory bases for optimizing drilling parameter of deep well and decreasing drill string fatigue failure.

The performance of organics and nitrogen removal as well as sludge reduction were investigated in a novel catching bed biofilm reactor which applies to decentralized wastewater treatment. The results indicate that the average removal rate of COD reached to 81.7% with different hydraulic retention time (HRT); Even HRT was only 2.94h, the average volumetric loading of NH₄⁺-N and TN were 0.65 kg/(m³⋅d) and 0.81 kg/(m³⋅d), the removal efficiencies of NH₄⁺-N and TN reached the climax about 74.7% and 65.2%. Protozoa and metazoan were observed on the biofilm and suspended sludge. The sludge yield was roughly achieved as 0.1465Kg MLSS/KgCOD_removed, which was only about 50% of the conventional aerobic processes.

This paper reviewed the characteristics, production process, production standards and applicable areas of fiberglass reinforced plastics (FRP) pipe, steel skeleton reinforced plastics composite pipe and flexible composite pipe. Comparing and analyzing the compound pipes with ordinary metal pipes and plastic pipes, it can be concluded that the compound pipe has its superiority especially in corrosion control in oil and gas engineering, and the future development direction of compound pipe was outlined. With raw material development and progress, production process improvement, cost performance rising and continuous quality improvement, compound pipes will continue to increase and widely used in such areas as high pressure, marine oil and gas exploitation. Compound pipe will become an important part of oil and gas pipes in the future.

In recent years, the gas storage well bolted out frequently everywhere. Those accidents usually result in the failure of the pipe's junctions on the shaft collar. Sometimes even the whole tub broke out from the ground. As a result, the natural gas leaks, gas storage well is abandoned, even causes big fire, explosion. Considered casing, cement mantle and layer as elastic material, elasticity theory and thick-cylinder theory were adopted; casing-cement-mantle layer model was built in the paper. Basic dynamic parameters of layer, geometric and physical parameters of cement mantle, and geometric parameters of casing were analyzed. The major failure causes and measurements to control gas well accidents were suggested in the paper.

Because the temperature of heat medium in the thermal pipeline is very high, which affects the pipe wall distortion and stress distribution, it is very important to analyze the thermal mechanical coupling in thermal pipeline. Numerical simulation of buried thermal pipeline damage under the earthquake action is analyzed by finite element method as basis of ADINA. Three-dimensional finite element modeling of buried thermal pipeline damage affected by site condition is investigated; geometry model is constructed with native and parasolid method in ADINA. The pipeline is modeled by native method and site is modeled by parasolid method, pipeline and soil are subtracted and merged by Boolean Operation. Gravity and earthquake force loads are defined in structure model, and temperature load in thermal model. In the structural model, pipeline is treated as thermoplastic material, and soil is treated as hot isotropic material. In thermal model, all materials are treated as heat conduction material. Thermal-mechanical coupling is calculated with the thermo-mechanical coupled analysis solver ADINA-TMC in ADINA. According to the calculating results of thermal-mechanical coupling, the damage of buried thermal pipeline is analyzed. Influence of single temperature load on the stress and strain of buried thermal pipeline is very small, but the stress and circumferential strain increase rapidly under earthquake action, especially, the axial strain is very complex. Under gravity and earthquake load, the temperature load mainly affects axial strain; the increasing temperature enables to reduce axial strain, which makes axial destruction reduced. Finally, some advice is proposed.

In this research, the mechanical characteristics of variable-diameter single pile under the combination of wind, wave and tidal current actions are studied. Take a variable-diameter single pile of CB11F platform as an example, finite element analysis is analyzed using ANSYS program. The parameters which affect the single pile response are analyzed, such as environmental loads, soil condition and position of variable-diameter. And the model of variable diameter section is simplified, from which the pile displacement and body stress under the action of wave and current are derived. Comparing the results with that of the equal-diameter pile model, the displacement and stress of variable-diameter pile model reduce more than 20%. So that, the effectiveness of the variable-diameter measure is verified in improving the mechanical properties of the pile

Researching on the Standard Practice for Direct Design of Precast Concrete Pipe for Jacking in Trenchless Construction (ASCE27-00) from American Society of Civil Engineers(ASCE), some mistake about the design maximum permissible jacking thrust force is found out and rectified. Finally, an improved formula is submitted and used to recalculate the design maximum permissible jacking thrust force.

High viscosity silt soil strata have been often encountered in trenchless engineering. Because of the high cohesion of such formations, greater shear stress is needed to destroy the soil mass, leading to many project accidents such as too large a torque placed on the drill pipe, difficulties in navigation, hole reaming and pipeline laying, delays in the construction period and cost increases, etc. A simple process to improve the drilling tools and drilling technique cannot solve these problems effectively in such strata. However, it's known that reducing the friction coefficient by changing the mechanical properties of the contact surface of borehole and drilling tool can reduce the required shear stress to overcome the problem of excessive torque. So the primary mean of handling such issues is to improve the performance of the filling liquid in the borehole-the drilling fluid. In this paper, laboratory experimental studies and molecular structure mechanism analysis of a common disaccharide organic compound were carried out on the influence of rheological parameters, lubrication coefficient, dispersion of the mud particle size, and expansibility of drilling fluid. It was found that a drilling fluid with such disaccharide organic compound can efficaciously reduce the friction, optimize rheology, enhance dispersion, etc. to reduce the high-torque engineering problem in such high viscosity silt soil strata. This drilling fluid has recently been used in practice and the application was successful.

Based on the autonomous driven principle of small-caliber robot, a new drive system of pipeline robot was developed with uniaxial dual-dirve peformance and adaptive control functions such as cross-space-driven, turn-driven guidance and steering. The obstacle-surmounting performance and self-centering performance of new drive system were analyzed. The results verified that the drive system can be better adapted to the environment and requirements of small-caliber Trenchless pipeline inspection. The theoretical basis was provided for the research on small-caliber trenchless pipeline robot with better drive capability, obstacle-surmounting performance and self-centering performance.

Ultra High Molecular Weight Polyethylene (UHMW-PE) is a kind of thermoplastic engineering plastic with excellent comprehensive properties which structure behaves linearly. Because of super high molecular weight, it has a series of outstanding properties with which no other types of plastic can compare. The method of molding in barrel is a new technology of pure UHMW-PE pipe continuous extrusion which overcomes the difficulties of pure UHMW-PE pipe molding. This article will introduce the main features of this technology. In accordance with relevant national standards, Pipe specimens are tested for properties analysis to provide valuable reference data for the engineering application of pure UHMWPE pipe. The test specimens are made from M-III UHMW-PE and GUR® UHMW-PE which are produced by Beijing Oriental Oil Co., Ltd. and TICONA.

The intelligent plugging technology in high-pressure pipelines is a novel plugging technology without tapping, and the sealing and locking capability are critical technology for plugs, which are respectively accomplished through sealing ring and locking slider. In order to design the seal better to generate an effective sealing effect against the pipe wall, firstly, the self locking mechanism of intelligent plug is introduced. Then the sealing condition of the seal is simulated by ANSYS software; the relationship between axial load, sealing differential pressure and contact pressure, as well as the influence of the sealing ring structure on the contact pressure are analyzed and calculated, hence optimal structure parameters are obtained for the height, oblique angle and outer diameter of the sealing ring, and the performance for withstanding differential pressure is improved and the sealing capability of the intelligent plugging technology in high-pressure pipelines is guaranteed.

As a substitute to traditional concrete sewage pipe, buried spiral steel plastic composite pipe has been applied in many countries and get attention and research of many experts and scholars because of its many merits such as relatively cheap, convenient in site installation, beneficial to environment, more perdurable. Point to this new type pipe, research actual of overseas and China are introduced. And its research development aspects and application prospect are analyzed and forecasted.

In order to improve the design accuracy and conduct risk evaluation for urban storm sewer system, a novel design concept named Storm Events-Oriented Design (SEOD), is proposed to improve the conventional Storm intensity Formula-Oriented Design (SFOD). Firstly, the conventional design method, SFOD, are reviewed and assessed. In addition, characteristics and advantages of SEOD are analyzed. Finally, three important steps for SEOD are outlined. The analysis results show that SEOD is a scientific and potential design methodology for urban storm sewer system.

Cruid oil in the ocean should be heated in the submarine oil pipeline transportation. Heat transfer of start-up is vital in design and plant supervision of submarine oil pipeline. Seawater natural convection in the most of starting transmission heat transfer calculation model of buried pipeline in the seabed was neglected currently. The model was right or not that was needed to verify by putting into production practically. There was an urgent need of offshore oilfield development to study starting transmission heat transfer calculation model of buried pipeline in the seabed. The thermal conditions of buried pipelines in the seabed were evaluated. The three-dimensional physical model and mathematical model of buried pipelines in the seabed were established. Effect of seawater natural convection in the starting transmission of buried pipeline in the seabed was analyzed. The model was simplified to one-dimensional cirque heat transfer model. Through simulation calculation and certification experiment tests, contrast studies show that these data are coincided, and some useful conclusions were drawn.

Based on the pipeline forces distinguishing features in collapsible loess area, a new Elastic-Plastic Foundation Model (EPFM) analyzing the suspended pipelines forces and deformations is established, which considers axial loads and foundation plastic deformations neglected in other available literatures. At the same time the calculating equations of pipeline forces and deformations are deduced. By the calculating software compiled based on the equations, an actual pipeline in collapsible loess area is calculated as example, then the calculated results have been compared with measured values, also the results by the Winkler model, and the influences of axial loads and foundation rigidity are analyzed. The comprehensive results addressed that axial loads have great influence on the calculating results, which should not be neglected in analysis and design of suspended pipelines. But the foundation rigidity has little affects to the pipeline stresses and deformations in the EPFM. The new EPFM is more accurate and suitable than Winkler model in calculating suspended pipeline stresses and deformations.

As a main construction technology, horizontal directional drilling has been widely applied. In this paper, technical principles, technical features, construction methods and present problems at present faced are introduced. Through using horizontal directional drilling technology, good social and economic benefits can be achieved. At the same time, according to existing discontentment and elastic deformation of stratum during the course of drilling under condition of trenchless construction stratum deformation will happen and corresponding mechanical parameters will be weakened. So a new back-analysis of FEM is put forward based on field-measured data. Before and after trenchless construction, the calculated results can reflect the changing law of geological stratum deformation modulus and of course the results not only can be used to assess the impacts on geological stratum brought by trenchless construction, but also can provide theoretical support to pipelines construction.

An air-lift pipeline system for exploiting and transporting solid materials under water was developed with pulsed water jet as the breaker and loosing device. Driven by the buoyancy of the injected compressed air in the liquid, the gas-liquid-sold mixtures mixed by the air-lift device could be transported upward in the lifting pipe. The oscillating pressure distribution around the suction pipe of air-lift produced by the self-excited oscillation pulsed jet was measured; it is found there was a fluctuating uplift force acting on solid particles. The lifting efficiency model of air-lift was proposed, and the operating performances of air-lift system with different water jet nozzles were investigated experimentally. The results indicated that concentration of the mixtures and energy efficiency of air-lift system were increased obviously with the breaking and agitating of waterjets.

With the development of economy, China water utilities evolve from having the single mission of meeting consumers' basic water requirement to supplying high quality water and ensuring water security. This paper presents the case study of building water distribution network digital analysis platform of H city in northeast China. A self-adapting water network model that adapts to water distribution network topology changes at a certain extent is built by the platform which is based on the water distribution network microscopic model, makes full use of the theories of mathematical programming, neurotic network, genetic algorithm, modern control, and geographic information system, and realizes multi-scenario analysis, optimization scheduling, optimization rehabilitation and expansion, and old and new water sources switching. With the platform, the old water source and the new one have been switched successfully and stable. It also ensures water distribution network optimal operation. Experience shows that water distribution network can effectively solves present problems of water utility and achieves good social and economic benefits.

The detection of oil and gas under trenchless is the important measure to grasp the status of pipeline and insure secure run of pipeline. The detection technology and equipment of small-caliber oil and gas pipeline are discussed for its detection requirement. The structure of drive system, detection system and assistant device are designed, the foundation of lucubration and manufacture exploitation are established for later.

When fluid passes through a bluff structure, it will separate, thus creating vortex and resulting in the coupled vibration between the fluid and structure. Under certain condition, the vibration is significant, and the structure will damage due to the reduction of fatigue life. With the development of ocean engineering into the deep water areas, it is very important to study the vortex-induced vibration of submarine pipelines. Due to the complexity of the problem, theoretical and experimental methods are usually used to study the problem simultaneously, and the latter is often more important. The model experiments are carried out in a laboratory in this study, and the experimental results reflect the main characteristics of vortex-induced vibration. Also, the experimental results and theoretical results are roughly consistent with each other. With the increment of the fluid velocity, the vortex shedding frequency will approach a natural frequency of the structure, and then the strong interaction between the fluid and structure will arise that the structures may damage.

Subsurface drip irrigation is a technology use for better management of irrigation water. This technique is more desirable in arid and semi-arid region, because of decreasing soil surface evaporation and more efficiency of irrigation system in comparison with the others irrigation systems. In addition this system is a safer way for treated wastewater reuse in irrigation lands. But roots and clay particles can clog drip emitters in systems buried below the soil surface. In this paper, sand and geotextile filtration methods have been suggested for solving root intrusion and biological plugging problems for subsurface drip applications. Sand envelope around the emitters has been recommended for deeper root zone and long term application of system, while geotextile envelope is suitable for seasonal crops with shallow root.

Accidental contamination is one of the biggest potential threats to urban water distribution systems. To take action to protect the water facilities, water authorities need to know the location of those high-risk nodes in water distribution network. High-risk node means that when contaminants were injected at those places, more hazards would be brought into the whole water distribution system. The sensitivity of nodes security is highly related to the hydraulic conditions of water distribution system as well as spatial location. Using a simulation tool, this study proposed a strategy for sensitivity analysis on node security through evaluating quantity of contamination accidents. Each node was assumed to be contaminant source with the same injection pattern, and then the simulation was performed. The contaminant effects on the whole system were evaluated by two measures: 1) the amount of residual contaminants left in the distribution system; 2) the count of contaminated nodes in the particular period. By combining these two data with weighted factors, the sensitivity on water quality security of each node was finally determined. Analysis on a sample network was incorporated to demonstrate the proposed method. This study provides a more reasonable tool for accidental contaminant risk assessment in water distribution system, as well as additional basis for optimal layout of early warning monitoring stations in water pipe network.

This paper presents the hazard factors and measure spaces of the seismic vulnerability for oil and gas long distance pipeline through the introduction of improved FAHP based on the holistic risk theory, and builds a seismic vulnerability evaluation model combined with probability and statistical method to calculate the probability of hazard factors and the value of seismic vulnerability, then draws the probability density curve and cumulative density curve of seismic vulnerability for pipeline unit. As a result, the value of vulnerability distribution interval and risk classification system under the seismic loads can be obtained. According to the seismic data and field data on the Guangyuan-Chengdu section of Lanzhou-Chengdu-Chongqing Products Oil Pipeline in Wenchuan earthquake, the result of this evaluation model is consistent with the pipeline performance in the actual. Therefore, the accuracy of the evaluation model can be verified.

This paper provides two types of engineering J estimation equations for welded piping branch junctions with poor penetration crack under internal pressure. The first type is the so-called GE/EPRI type J estimation equation based on Ramberg -Osgood (R-O) materials. Based on detailed 3-D FE results using deformation plasticity, plastic influence functions for fully plastic J components are tabulated for practical ranges of the inner radius of brace to the inner radius of chord ratio, the thickness of brace to the thickness of chord, the thickness of chord to the inner radius of chord ratio, the crack depth to the thickness of chord ratio, the strain hardening index for the R-O material, and the location along the poor penetration crack front. Based on tabulated plastic influence functions, the GE/EPRI-type J estimation equation along the crack front is proposed. For more general application, the effective remote stress method based on GE/EPRI-type solutions is provided. This method provides a simpler equation for J, which could be used for any stress-strain relationship material, including Ramborg-Osgood(R-O) material and non-R-O materials under monotonic increasing loading. The proposed effective remote stress based J estimation equation is compared with elastic-plastic 3-D FE results using actual stress-strain data for a Type 304 strain less steel. Good agreement between the FE results and the proposed reference stress based J estimation provides confidence in the use of the proposed method for elastic-plastic fracture mechanics of pressurized welded piping branch junction.

Reinforced thermoplastic pipes (RTPs) are being increasing used in China National Petroleum Corporation(CNPC), owing to their good corrosion resistance and easily installation technique. Several thousand kilometers of RTPs has been deployed in natural gas transporting system in Changqing Oilfield since 2007. After one year serving of PET fiber reinforced polyethylene pipe, several failures happened. Therefore, it is necessary to study the effects of environmental factors, including temperature and installation damages, on the strength of PET fiber and RTPs. The primary failure modes of RTP pipe are analyzed and the residual strength tests of RTP pipes, which are cut from the pipes near the failure spot, are carried out. The result shows that the strength of RTP pipe decreases with increase of temperature from 0°C to 65°C. The damages of the protective layer (the outer layer) have little influence on the strength of pipe, while those damages of reinforced fiber layer have much influence. Finally, some suggestions are given for future application of RTPs in Oilfield(Jerry, 2000).

According to the practical problems encountered in horizontal directional drilling, a comprehensive analysis of the main factors of drill pipes' failure has been done. Based on the drill string dynamics, the paper have studied the influence on the drill pipes' failure of the space between hole and pipes from the perspective of bending stress, and proposed the measures for the prevention of drill pipes' failure.

A new fatigue life prediction method is developed in order to predict the fatigue life of submarine pipeline free span in ChengDao oilfield under the wave force. The high-cycle multi-level fatigue test is carried out with the specimens from the submarine pipeline free span (X60) used in ChengDao oilfield. The fatigue lives and their probability statistical distribution of X60 steel are obtained. The numerical simulation results show that the fatigue logarithmic life of specimens have a linear relationship with the survival rate. And the P-S-N curve of specimens and the linear formulas between the fatigue logarithmic life and the cyclic stress under different survival rates are obtained. Finally, the P-S-N curve formula is developed by introducing the unsymmetrical cycle coefficient φ_eq–M, so that it can be used directly in the fatigue life prediction for the practical submarine pipeline free span (X60).

In this paper, the failure types of fiberglass reinforced plastics (FRP) pipe in oil and gas engineering were reviewed. The main failure types, such as attachment joint failure, corrosion-induced failure, temperature-induced failure, impact failure, bend failure, tensile failure, stress failure, improperly installation and other type failures were introduced. The causes of failure including design, selecting defective material, manufacturing process, reprocessing, assembling, inspection, testing, quality control, storage and transportation, working conditions, installation, maintenance and mechanical or chemical damage were analyzed, general guiding principles of failure prevention were outlined. Correct choice of resin glass fiber source material, a comprehensive quality testing and strict enforcement of the correct installation procedures, installation tools and guidance prior to use can be effective in preventing the occurrence of these failures.

The dent on the pipeline is one of the important factors that influence the pipeline strength. Many international pipeline design standards generally use the dent depth to appraise whether the dented pipeline needs to be repaired. However, most of the dents that satisfied the standard still to be able to fail, so need to analyze more parameters that influence the dent strength and find out the relationship between them. Using the finite element method, the finite element models were established under different circumstances, and the strength of the dented pipeline that was applied internal pressure was calculated. Non-linear regression analysis was utilized to fit the results by Matlab, then the expressions of the relationships between the dented pipeline strength and the geometric parameters of dent, pipeline diameter, wall thickness and internal pressure were obtained under different circumstances. This can be used as part of the basic research of the pipeline design standards, and improve the accuracy of the dented pipeline assessment, as well as ensure that the security and reliability of the pipeline design and operation.

Effects of formation of the disinfection by-products (DBPs), trihalomethanes (THMs), of chlorination were investigated through static bulk-water experiments. In this research, effects including organic matter, chlorine dosage, bromide, reaction time of chlorination, temperature, PH value and ammonia nitrogen were investigated. The results showed that all effects accelerated THMs formation except that of ammonia nitrogen; there is a good linear relationship between TOC, UV₂₅₄ and THMs, the correlation of UV₂₅₄ is better than TOC, and UV₂₅₄ can reflect changes of THMs formation better; when Cl₂/TOC<0.2, little THMs was formed; when Cl₂/TOC=0.2~2, chlorine decay was linearly related with THMs; when Cl₂/TOC>2, THMs increase was not distinct; bromide levels has great influence on the total formation amount of THMs. THMs increases with the increase of bromide levels, and chloroform decreases, while the other three kinds of bromo-halocarbon increased, especially bromoform. The conclusions of research would put forwards some suggestions to control and reduce THMs, ensuring safety water quality.

The present work was to investigate the nitrogen-existing forms of monosodium glutamate wastewater and the effects of HRT, organic loading and biomass on the transformation of nitrogen in the full-scale operation of two-phase anaerobic process. The ratio of ammoniacal nitrogen (NH₄⁺-N) to total nitrogen (TN) varied from 0.5 in acidogenic phase reactor (Phase I) to 0.85 in methanogenic phase(Phase II), which indicated that ammonium had already become the leading form in Phase II. The ammonia-releasing amount varied greatly at different hydraulic retention time (HRT), especially with the lower HRT of 15h in Phase I and 50h in Phase II, which the ammonia-releasing increased as the decreased HRT on the day 70 to 90. Calculated the removal rate of COD and TN in the different heights of the methanogenic reactor, the values of COD_rem/TN_rem obtained from the height of 3.0–5.0m and 5.0–10.0m were 22.2:1 and 12.0:1 respectively. The reduction of TN concentration in the height of 5.0–10.0m was 244.5mg/l that was almost 45 percents of the total reduction in Phase II, but the mean sludge concentration of 2698.7mg/l in the height of 5.0–10.0m was lower than the mean sludge concentration of 8943.3mg/l in the height of 3.0–5.0m. The nitrogen imbalance was occurred in the post section of the methanogenic reactor.

THMs variety orderliness in water network was analyzed. Based on analysis of research improvement, experiment was carried out in laboratory and water network, and the results showed that THMs formed in water network is 30% of total formation. Formation of THMs was caused by change of hydraulic condition. Based on the result, THMs formation kinetics model was advanced on real water network.

The coal liquefaction wastewater contained a very high concentration of sulfide that couldn't be treated directly through the traditional biological process. The removal of sulfide was important to the further treatment process. The gas stripping process with the addition of acid was selected to eliminate the sulfide in this study. The effect of gas stripping time and rates, acid addition, and different carrier gas were investigated respectively to explore the optimum condition for the sulfide removal. Results indicated the longer gas stripping time, larger gas intensity and more acid addition were beneficial to the sulfide removal. The removal efficiencies were over 98% when the sulfuric acid addition exceeded 40ml/L and the gas stripping time was within 2h at a gas rate of 60L/h. Considered the appropriate gas-water ratio for recovering hydrogen sulfide and the advisable pH value for post-treatment of the wastewater, the optimum condition was obtained from the sulfuric acid addition between 40 to 50ml/L and the gas stripping rate between 60 to 120L_gas/h at the time of 2h.