ICPTT 2012: Better Pipeline Infrastructure for a Better Life

Over the last 10 years, many large-scale water transmission projects which made extensive use of Pre-Stressed Concrete Cylinder Pipe (PCCP) have been constructed in China. PCCP correctly designed and manufactured is a skillfully engineered composite pipe that exploits concrete in compression and steel in tension to create an economical, efficient, and long-lasting product. However, if it is improperly installed or poorly made, PCCP may rupture due to corrosion and breakage of the high-strength prestressing wires that reinforce the pipe. Electromagnetic inspection has been successfully used in accurate condition assessment of PCCP in China. Since many pipelines cannot be taken out of service, manned EM inspection can only be used to inspect empty or depressurized pipeline. An innovative free-swimming EM inspection system has been developed recently. The principle, analysis method of this free-swimming system is introduced. Several field applications indicate that the system is capable of conducting EM inspection in live pipeline. EM surveys, whether undertaken in wet or dry pipeline, enable owners to estimate remaining pipe life and, if necessary, plan the timed removal of defective pipes which are likely to fail. The paper provides examples of surveys conducted in the Americas.

The filled embankment of interoperability joints on Yang-Yi Highway in Qinshui slipped on September 30, 2011. It resulted in cut-off drains and culverts of the damaged highway and ruptured CBM pipeline. To curb deformation of landslide that may intensify to harm the pipe further as soon as possible, emergency reinforcements of prestressed anchor cable frame have been constructed, which is located on both sides of pipelines on lower slope of the Yang-Yi highway and the old highway. Using the FLAC3D procedures to establish landslide numerical model, then the sliding surface is dispersed by contact element and obtained by calculating the three-dimensional stress state on Interface node. The author defines the point safety factor on Interface as the ratio of the shear strength of the node to the sliding force. The mechanism deformation and reinforcement is analyzed through the point of the distribution characteristics of the safety factor. The research indicates that the distribution of point safety factor on Interface shows the same regularity as the landslide macroscopic deformation and the reinforcing effect reflected by on-site monitoring data. As a result, point safety factor on Interface can be taken as a quantitative assessment index of treatment project of landslides.

In 2011 at the Diamond Peak Ski Resort, a 1800'-, 72''-long CMP culvert needed to be evaluated for structural and hydraulic capacity. CCTV inspection was performed by a professional company and high-quality data was provided. A new condition assessment method for culverts was proposed and utilized for this project. It is based on the culvert rating system originally developed by Mr. R. Trevis from Oregon DOT to evaluate the severity of the culvert and recently advanced by Dr. C. Yang during his PhD research. A comparison between the new assessment method and the traditional assessment methods used by professional engineers was provided and a rehabilitation and replacement plan was proposed based on the culvert condition rating report. This paper evaluates the applicability of the proposed culvert rating system in a real project, which demonstrates that this standardized culvert rating system is a valuable tool in the asset management of culverts.

The frozen soils distribute extensively in China. The east-west and the northern pipelines are mostly buried in such regions. China is also an earthquake-prone country. Once seismic conditions are considered in the frozen regions, the performance of pipelines will face many problems. The finite element method was used to analyze the seismic responses of pipelines in different frost heaving conditions. The time-history responses of displacement and acceleration of pipelines in different frost heaving conditions were obtained, and the results were also compared and analyzed. The results indicate that the different conditions of frozen soils should be considered in seismic responses of pipelines to make the pipelines in safety and economy, and more attention should be paid to the design and study of pipelines in frozen soils.

Storm drainage systems should provide effective means of removing excessive rain water from urban areas. The majority of existing storm drainage systems have been constructed without considering global climate change and its new precipitation trends. New or existing storm drainage systems should be designed and upgraded to effectively regulate stormwater without increasing risks to public safety or causing social and economic damage. Furthermore, most existing storm drainage systems need proper asset management, higher hydraulic capacity to capture more stormwater, adequate storage capability to manage flow, and overflow control. The majority of urban storm drainage systems consist of in-line drainage pipelines and off-line storage facilities for temporary flow control. An off-line tunnel storage system is one of the best applicable options to mitigate urban flood risk without significant upgrading or adding new in-line storm drainage pipelines and storage. The tunnel boring machine (TBM) has been selected for most stormwater storage tunnel construction methods. Other trenchless technologies using various repair, rehabilitation, and replacement methods can also be used as sustainable construction methods for storm pipelines. This paper suggests various sustainable applications. The authors also propose a strategic implementation plan for new sustainable trenchless technology including TBM and low-impact design (LID) applications to mitigate urban flooding risks.

Water utilities have become more and more concerned with the service performance, reliability and resilience of water distribution systems (WDS). The objective of this study is to develop a software tool based on GIS for the comprehensive analysis and assessment of WDS. The software integrates EPANET to perform hydraulic and water quality simulations. The software consists of three modules: performance assessment, reliability analysis and post-earthquake restorability estimation. The module of the performance assessment comprises three elements: i.e., state variable, service curve and operator function. In the reliability analysis module, the reliability index of the node is obtained by the use of Euclidean distance. The nodal demands are weighted to generate the reliability index of the entire network system. In the module of the post-earthquake restorability estimation, the leakage magnitude is modeled and a hydraulic simulation is performed by EPANET. The restorability of the entire network system can be evaluated by the software. The outputs of the software can give a straightforward understanding of the results that contribute to the knowledge of the water distribution system.

For the multi-function cathodic protection test probe, the structure and relative displacement between coupons is always a crucial problem. In this paper, the effect of the polarized coupon on the potential of the corrosion coupon and stray current interference were studied when coupons were set in two different arrangements. The results showed that, the smaller the area of the polarized coupon was relative to the corrosion coupon or the larger the space between coupons was, the stronger the performance of anti-interference of test probe by itself or the stray current was when in parallel arrangement, and it was reasonable that the area of the coupon from pipeline with coating of good quality was 1cm2; when in concentric arrangement, the geometric center of the coupon had the best performance of anti-interference, thus, with regard to pipeline with coating of poor quality but requiring coupons of larger area to simulate the holiday, the polarized coupon and the corrosion coupon could be made as circular ring type and be arranged concentrically and horizontally in the bottom of the probe of which the center was the reference electrode.

Erosion-corrosion is a complex phenomenon in high-pressure pipe manifolds which may be caused by working ages, fracturing fluid and sand. It results in some amount of equipment failure and material loss. Consequently, it is necessary to improve erosion wear resistance of high pressure pipe manifolds in engineering. The aim of this work is to investigate the role of different parameters influencing erosion-corrosion. A new type of erosion tester was used as the test apparatus and test parameters such as impact time, sand size, flow velocity, impact angles and test solutions were varied to study their effect on erosion wear of 40CrNi2Mo alloy steel. The results indicate that the mass loss increases with time, sand size, and flow velocity. The most mass loss occurs at 30°. The erosion wear characteristic feature is micro-cutting action and the distortion wear, which is the same to the erosion wear rules of the typical plastic material.

Corrosion is the main factor which influences the reliability and the remaining life of the mixed transmission underground pipeline. Since this research is in the initial stage in China, it's necessary to calculate the remaining life of the corroded pipeline and research on it. This paper firstly reviewed some kinds of the remaining life calculation models, where the characteristics of the mixed transmission pipeline and the difficulties to calculate the remaining life are considered. Secondly, several influencing factors of mixed transmission underground pipeline corrosion are summarized, such as the soil surroundings, material characteristic, manufacturing process, transmission medium, leading pressure state and the parameter of the anticorrosion in and out. Finally, the remaining life of the mixed transmission underground pipeline is predicted using this approach, and the results are in accord with the real conditions.

The submarine pipelines are vulnerable to physical factors, chemical factors and biological factors, and then lead to corrosion. The destruction of the submarine pipelines is larger and more difficult to repair than land-based pipelines. This paper focuses on the analysis of influence factors of corrosion in sea mud, internal corrosion in pipelines, seawater corrosion, atmospheric corrosion, and other corrosion. With the corrosion failure of submarine pipelines as top event, the fault tree has been established. Through systematically qualitative analysis of the corrosion factors and structural importance, the conclusion was reached on how the above five kinds of corrosion and status of anti-corrosive coating affect the degree of submarine pipeline corrosion failure. Finally, the main influence factors of the submarine pipeline corrosion failure are determined, and so the correlative solving measures of the main influence factors are proposed in the article.

Newly built pipeline stations in China have widely used a cathodic protection system using flexible anodes and grid anodes. However, there may be some places in a pipeline station where the lack of protection may not be apparent because the data collected from several test posts cannot accurately represent the entire protection system in the station. After numerical simulation of an ideal case without interference from other metals, the results show uniform distribution in a flexible anodes system. But, if a grounding system exists in the model, interference will greatly influence the potential distribution. The result shows the potential distribution is no longer uniform and portions of pipe near the grounding system may not be protected. Due to the differences between characteristics of polarization in the grounding system and the pipeline, the addition of a sacrificial anodesystem is advised.

An indoor simulation equipment for DC interference corrosion was established to evaluate the relationship among outflowing current density, soil types and corrosion behavior of 16MnR steel. The influence of testing mode for that equipment was also investigated. The results show that: (1)The mode of "constant current cathodic protection & constant DC current interference" was the best operating mode of the indoor simulation equipment; (2) the corrosion behavior of DC stray interference was dominated by the DC interference intensity, while the influence of soil which hardens performance on corrosion behavior was significant; (3) the corrosion rate was proportional to the outflowing DC current density of specimen, but the characteristics of localized corrosion was more obvious with the increase of the corrosivity of soil.

The forecast accuracy of combining model can be substantially improved, for it benefits from the individual forecasts on different levels of the input data space. This paper provides a description of forecast combination techniques and puts forward a combining forecasting model of non-negative time variant weights. The combination forecasting function is a multi-peak value, and Artificial Immune Algorithm is applied to search multi-modal function's multi-extremism. Then, the combining forecasting model of non-negative time variant weights is applied to forecast the corrosion rate of the certain pipeline, and the error rates obtained from individual models and combining model show that the latter achieves an improvement of forecast quality up to 95 percent. That indicates the best results can be achieved by using combination models, and Artificial Immune Algorithm has validity and accuracy to solve the combination forecast problems.

Normally, the maximum continuous in-service operating temperature of 3-layer polyethylene (3LPE) coating is not more than 70° C. In order to solve the problem of pipeline coating under temperatures higher than 80° C, especially for crude oil pipeline, a 3-layer polypropylene (3LPP) coating structure has been developed and applied in practice both domestically and abroad. However, at the present time, only one form of field joint coating based on polypropylene shrinkable tape is widely adopted for 3LPP coating. This paper will introduce the pioneering work of a new field joint technology based on solvent-free epoxy, viscoelastic, and PE heat-shrinkable tapes. Also discussed are the selection of new filed joint coating materials, the establishment and testing of the filed joint coating overall performance, and the application of this new field joint technology on the Chad crude oil pipeline project.

A more flexible grounding resistance calculation method, based on finite element analysis (FEA) method, is suggested, which is especially suitable for optimization cathodic protection (CP) ground-bed arrangement. As compared with traditional grounding resistance evaluation method, which is only suitable for the case of each anode rod in a straight line, the FEA method can calculate grounding resistance of ground-bed at any arrangement. Moreover, a realistic soil resistance rate, usually varying with depth, can be included in calculation model. The detailed steps for this method can be summarized as follow: building a 3D geometric model according to general design, meshing the geometric model, setting reasonable boundary conditions, solving and post-solving the grounding resistance with ohmic law. To further explain this procedure, a realistic CP ground-bed displacing project is presented, which includes displacing the original CP ground-bed firstly and re-designing a new ground-bed within a limited area (5m×30m). A new CP ground-bed design, compared with traditional design, 2×7, 14 anode rods dispersed in two parallel groups, are calculated firstly. The results show that this design can not meet the grounding resistance requirement. Another 4 designs, with anode rods arranged as 2×6, 2×8, 2×9, 3×6 are calculated respectively. Finally, the design 2×8 is recommended from the view of economy and practicability.

Since the majority of pipelines in China are required to be installed underground, external corrosion becomes a major threat to their useful lifetime. The factors affecting the likelihood and severity of external corrosion of buried pipelines includes soil corrosivity, coatings, presence of moisture (e.g., river crossing), electrical fields, cathodic protection system, coatings, etc. In order to help understand the potential impact of this problem, a survey of a 70-km gas pipeline was conducted, including measurements of soil corrosivity, soil resistivity, stray electrical currents, IR drop, depth of cover, coating integrity, and the effectiveness of cathodic protection. Additional information was collected regarding interference potential by Pipeline Current Mapper (PCM),Closed Interval Potential Survey (CIPS), and Direct Current Voltage Gradient (DCVG) techniques. The collected information was integrated into a database which was used to build a non-linear model using the Support Vector Machine (SVM) method. By investigating the non-linear relationship among these factors with respect to their influence on the external corrosion of pipelines, it is possible to predict the most likely locations of external corrosion along other pipelines. The model was applied to another (50 km) pipeline and the results indicate the method is accurate and efficient.

With China's rapid development of the petrochemical industry and an improvement in city utilities (water, gas, and sewer services), underground pipelines are literally the "lifeline of city." However, corrosion can cause perforations that will eventually lead to leakage accidents creating an Underground Pipeline Hazard or "time bomb" when gas explosions or sewage leakage occur. Corrosion protection has been related to the pipeline reliability and service life, it also relates to people's livelihood and security. This paper analyzes underground pipeline corrosion as a cause for potential harm and offers specific measures of protection.

The corrosion behavior of X80 and X70 pipeline steels in Beijing soil environment was investigated by burying test in nature field for one and two years, while using SEM and XRD analyze the micro-morphology and phase composition of corrosion products of X80 and X70 pipeline steels. The results show that general corrosion has occurred mainly on the X80 and X70 pipeline steels in Beijing soil, with the pitting corrosion. With the increase of burying time, the corrosion rate of X80 and X70 pipeline steels remain steady, and the pitting corrosion depth increases. The corrosion rate of X80 steel is lower than that of X70 steel, and the pitting corrosion degree of X70 steel is more than X80 steel. The corrosion product of X80 and X70 pipeline steels can not protect the substrate, because of its incomplete, loose and incompact, and was consisted of α-FeOOH, β-FeOOH, γ-FeOOH, γ-Fe2O3 and Fe2O3. X80 steel exhibits higher corrosion resistance than X70 steel.

Due to rapid development of HVAC transmission lines, AC electric railways and oil and gas pipelines, these lines will inevitably cross or lie parallel to each other. At these position pipelines will be subject to serious interferences. In most situations, only the results of an interference are detectable, with no clue as to what caused the problem. This paper presents a new method designed to solve AC interference. When the interference source cannot be determined, AC voltages of buried pipelines are first measured and the AC interference is simulated. Furthermore, a mitigation method is built using computer software. After mitigation devices are installed on the pipeline, AC voltages are simulated once more and compared with field-measured values. The result shows that the simulated AC interference and the subsequent mitigation method built with computer software are more efficient.

Tazhong-1 gas field is one of the major gas sources in "West-East Second-line". Its ground gathering pipeline network, including TZ62, TZ82 and TZ83 well areas, was seriously corroded by the produced fluid from Tazhong-1 gas field, and the pipeline corrosion rate exceeded 1.234 mm per year. The investigation showed that the type of corrosion found in the ground pipeline network in TZ62 and TZ83 was influenced by CO2 and H2S, but H2S corrosion was the major factor (PH2S>6.9×10-5MPa), while the type of corrosion found in the ground pipeline network in TZ82 had moderate CO2 corrosion (0.021MPa≤ PCO2≤0.21MPa). Many literature reviews have proven that the degree of corrosion in ground gathering pipeline network is retarded by adding corrosion inhibitors. However, the industrial corrosion inhibitors can't satisfy field requirements. Thus, in this paper, the corrosion inhibitors MY-1, HG-1 and MY-2 were synthesized, and their corrosion inhibition efficiencies were investigated and compared with industrial products TH-2B and TH-1C. The results showed that the inhibitor performance of MY-1 was the best (inhibiting rate is 82.8%). Furthermore, complex inhibitor YT-1 mixed with MY-1 and HG-1 was investigated in corrosion environment which simulated the ground gathering pipeline network of the three well areas. The results showed that YT-1 dosage within 150 to 200 mg/L could control the corrosion rate of the ground gathering pipeline network less than 0.076 mm per year in TZ62, TZ82 and TZ83 well areas, and the property of the YT-1 could measure up to the first degree of the standard for corrosion inhibitors.

In this study, an electrochemical testing method is studied and intented to be used for online monitoring for corrosion control in pipelines of produced water reinjection in Shengli Oilfield. Corrosion inhibitors are used in the pipeline. The factors that affect the corrosion rate are investigated in laborotary, including temperature, flow velocity, pH and NaCl concentration. Corrosion inhibitors are assessed and their effectiveness is monitored using the electrochemical testing method. An on-line corrosion monitoring scheme is designed to monitor the corrosion state and inhibitor performance of the pipeline. This new method can assess the quality of corrosion inhibitors and their anti-corrosion efficiency instantaneously.

Under constraint conditions of freezing point of crude oil and wellhead back pressure, the mathematical models of the solidification pipeline in the gathering lines under carbon dioxide flood were set up, and the relevant numerical calculation methods were given. Taking 5 oil wells, such as S378-J245 well in the Dong 14 of Yushulin Oilfield of Daqing Oilfield, etc. as examples, the solidification pipeline in the gathering lines was calculated by the mathematical models and the numerical calculation methods mentioned above. The results show that the gathering lines under carbon dioxide flood are more possible to be solidified than that under water flood.

This study deals with the complex problems of wellbore collapse and hole shrinkage during drilling process in Jilin Oilfield. Analysis of lithological characteristics and mineral compositions of the representative reservoir cores, revealed that the reservoir cores have microcracks development in the region. The cores mainly composed of brittle shale and soft mudstone with high contents of illite-smectite, belonging to the strata of strong water-sensitivity and easy to collapse. Based on the principles of aluminum chemistry, optimization and compounding of aluminum salt anti-collapse inhibitors was experimentally formulated. The formation of aluminum matrix drilling fluid system in combination with other additives was also established, and evaluation of the system's rheology, fliter loss, temperature resistance, inhibition and anti-pollution were carried out. Finally, the aluminum matrix drilling fluid system with strong anti-collapse capacity was developed. The on-site applications of 14 wells in Jilin Oilfield related blocks show that compared to the previous anti-collapse system, the aluminum matrix drilling fluid system eliminated the problems of sticking by fast dropping, hang sticking during pulling out of hole and slacking during running in hole caused by wellbore collapsing and hole shrinkage, thus, greatly reducing the accidents' rate.

Long-distance pipeline pigging and pressure testing is an important process for pipeline construction. In this process, the comprehensive property which includes the mechanical performance, manufacturing quality and construction quality of pipeline will be tested. Meanwhile, pipeline running salty on the design pressure in the operation process is inspected. The effect of long-distance pipeline pigging and pressure testing work depends on many factors, such as type selection of equipment, height difference of terrain, segment technology and construction process. Each of the factors is closely related to the safety, efficiency and success or failure of this work. In this paper, the pigging and pressure testing program in large diameter pipeline is studied during the construction process of western pipeline. Firstly, equipments are selected rationally, including air compressor, feed and booster pump, pressure test head, pig. Secondly, segment of pigging and pressure testing is simplified. Finally, measures of dealing troubles in pigging are optimized, for example, air leakage of pig and get stuck. By taking these measures, we designed the program of a section of gas transmitting from west to east project. The practice shows that construction period is shortened and equipment capacity factor is improved obviously. In short, these measures are helpful to pigging and pressure testing in long-distance pipeline for enhancing effect, saving energy and safety.

For the vast territory of China, numerous oil and gas pipelines have to pass the high incidence area of earthquake, which has great menace to the safety of oil and gas pipelines in these areas. In the paper, the finite element model (FEM) is established to obtain the nonlinear dynamic response model of pipeline under seismic loads. The numerical methods are used to solve the model. At the same time, a field pipeline is calculated as an example. Moreover, the effects of seismic intensity, spring stiffness, resistance ratio, and site type, etc., on the response law, stress, deformation, and acceleration of pipeline are studied. The results show that the seismic response of pipelines increases as the increase of earthquake intensity. When the damping ratio keeps stationary, the seismic response of pipeline increases with increasing stiffness coefficient, whereas the displacement decreases gradually and basically has an inverse proportion with stiffness coefficient. The seismic response of the pipeline increases with increasing damping ratio, and the displacement and the stress gradually decrease under the same stiffness coefficient. The seismic response of pipeline has a relation with field. When the site soil gradually transits from the hard soil or rock to soft soil, the maximum displacement of the pipeline does not become larger, indicating the soft soil could reduce the damage of pipeline in earthquake.

The S135 drill pipe occurred failure accident for direction crossing rivers during West-East natural gas transmission. In order to analyze the failure reason, this paper carries on the overall analysis to the drill pipe sample based on the magnetic particle testing, fractography, and metallography, et.al. The analysis discovers that: the fracture has many cycle cracks and the sulfur content in the lateral fracture is higher than that in the other area of the drill pipe. The cracks show the typical characteristic of hydrogen sulfide stress corrosion cracking. It concludes that the fractures are hydrogen sulfide stress corrosion cracking. The drill pipe with anti-hydrogen sulfide property should be used and the drill pipe should be stored for a period before using in this oil field.

At present the gas transmission pipeline stress analysis is mainly aimed at ordinary buried pipe. Stress analysis is less for gas pipeline in tunnels, especially on the pressure testing condition. Usually testing pressure is greater than working pressure, it is necessary to know the stress distribution of passing-through gas pipeline on pressure testing condition. This paper established pipe stress analysis model for XX gas transmission pipeline in shaft of shield tunnel on pressure testing condition by CAESAR II software. This paper gets the gas pipe stress distribution, clearly determined the stress key points, checked the strength of the pipeline. This method provides guidance for gas pipeline stress analysis.

A two-dimensional model of natural gas explosion characteristics for premixed combustible mixture was established. In the model, considering control action imposed on an explosion from turbulence and chemical reaction kinetics, a turbulent combustion model coupled with reduced mechanism of detailed chemical reaction kinetics was set up. The governing equations of flow and the reaction equations were solved simultaneously (i.e., coupled together) by the finite volume method (FVM). Explosive characteristics and rules for natural gas in pipelines were studied by numerical simulation. The conclusions made in the paper laid a foundation for further studies of the flammable gas explosion process and the prevention of an explosion disaster.

Recently several LNG receiving terminals have been built along the seacoast areas in China. Simultaneously some LNG terminals are in construction and a number of other terminals are in the schedule. Till now, most other LNG terminals are set the custody metering outlet the terminal after the LNG being regasified, and the natural gas metering is the volume measurement except for a few terminals. LNG unloaded from the vessel is level measurement and the onshore metering of LNG is used to contrast and check as a reference. While for the object metering method and essential measurement energy custody measurement is necessary. Firstly, this will ensure the veracity of the medium quantity; secondly, will differentiate independent function part measurement definitely and make interface clear to prevent dispute. So the factors to improve the precision and reliability of the energy measurement in each key links such as, LNG vessel measurement, LNG unloading measurement, processing boil-off gas measurement and regasified natural gas measurement shall be analyzed. The optimization methods to measure the temperature, the pressure, the level, the density, the medium components and the heating value are used. Then ensuring the measurement with suitable instruments of their accuracy, repeatability and reliability, the method to improve the parameter avoiding the error, and the system potential Uncertainty, optimum algorithm and program calculation, will be developed analyzed with details.

Application of the chemistry-microbial methods, the heavy oil viscosity reduction experiment was conducted. Selection of a single strain F-2 and hybrid strain F-23 as viscosity reduction agents, the effect of processing time, temperature, nutrient source and other factors on the viscosity reduction were investigated. The results show that the optimum processing time was 6d, temperature was 45¢C, simultaneously needed to add nitrogen and phosphorus source. In this experimental conditions, the heavy oil viscosity eventually reduced to 116.45mPa⋅s, the rate of viscosity reduction increased to 99.15%, solidifying point reduced to 22.0¢C, pour point margin of 5.5¢C, which shown that complex viscosity reduction process could improve the properties of heavy oil, thus this technology could be used in heavy oil gathering and transportation. The follow-up experiment was also carried out to study the demulsification of wastewater treatment, select SP-169 as de-emulsifying agent, the best demulsification and viscosity reduction conditions were obtained through the orthogonal experiment were determined: the best temperature, processing time and adding amount were 30¢C, 20min and 100mg/L respectively, the rate of dehydration reached to 99.35%.

According to characteristics of pipeline sediment transport, this paper has put forward a pipeline sediment transport pattern where drag smooth region meets drag similarity according to Reynolds similarity criterion and can take design method of model silt concentration scale. Energy loss deviation resulted from differences between prototype and model of muddy water density which shall be calibrated in the process of silt concentration scale design.

Application of non-metallic pipe systems in oilfields in China was discussed in this paper. Firstly, kinds of composite pipes mostly used in Chinese oilfields were introduced and consumption of composite pipes of different kinds in oilfields from China National Petroleum Corporation, the largest oil & gas corporation in China, was reviewed. Secondly, problems of composite pipes in service and main reasons were discussed, and some suggestions were also given. Finally, future application of non-metallic pipes in oilfields in China was forecast.

It is the essential sign of the modernized level that the urban heating networks operate regularly and with high efficiency. It has already reached agreements to build urban heating network GIS and improve the decision level of heating network. By in-depth studying the status of the urban heating networks GIS, we point out the main problem; that is, the heating network GIS evolution of our country. Especially, the emergency warning and response function of assistant decision system is extremely discussed. Finally, this paper also put forward some suggestions on the perspective and research direction of urban heating network GIS in future. To sum up, it will be a major trend of development that some subsystem involving the automatic monitoring, optimizing operation dispatching and emergency warning, realizing digitalization, visualization and intelligent decision may be comprehended on the flat of urban heating network GIS.

The pipe network has throughout each corner and entrance thousands of families with the constant development and expansion of gas pipeline in our country; it also has provided our life with more convenience. However, since geological conditions and surrounding environment of gas pipeline are very complex, and gas transportation in pipeline is flammable, explosive, toxic and pernicious; once leakage happens in pipeline, it is apt to cause combustion, explosion accident, casualties and enormous property losses. Therefore, pipeline security has gradually become a critical concern of the country and the whole society. Taking geographic information system (GIS) as a platform, a set of city natural gas pipe network risk management information system was developed using the MapX C/S structure pattern in this study, which can realize real time inquiry of pipeline basic information and security evaluation. It has also set up a variety of emergency response measures and rescue proposals when an accident takes place. It offers technical support for incident succor and emergency response management. It also can forecast a variety of consequences such as flame, blast and leakage accident through invoke background program; the coverage of incident can be shown in graphs. It can provide optimized rescue route and personnel evacuation path, supporting technically for rescue decision making.

Since the data of underground pipelines (such as pipeline type, distribution and location, etc.) are missing or biased in modern cities, underground pipelines are usually damaged during construction, which cause lots of accidents. How to manage underground pipelines data effectively becomes a focused issue. The solution of this issue will greatly improve the utilization efficiency of underground space and the level of city management. An information management system is designed for underground pipelines in this paper by using B/S (Browser/Server) architecture. The database is designed in the server to store the pipeline data. MapServer, an open source GIS software, is applied to provide information services via networks. Users can find and modify the pipeline data using the browsers (such as IE, Firefox etc.). Therefore, users can manage information easily. For example, users can obtain the information of existed pipelines in the trenchless site and add new data to the system through wireless network. In addition, the virtual reality modeling language (VRML) is also used to get the 3D display for the pipelines in this system. Compared with the conventional management based on paper documents, this system has many advantages, such as convenient for storage, large storage capacity, good compatibility, easy to modify and query etc..

Aiming at the possible hazards that a pipe will face when crossing the goaf, preliminary analysis and assessment was given in this paper. Firstly, basic parameters in surface movement were determined using comprehensive factor P for rock character evaluation. Based on probability integral method of surface residual movement, the analysis for main section of mined-out area was completed. The results showed that the goaf had not yet been fully stable and the pipeline would be in risk of damage. Secondly, two models were introduced. One was single beam model, for the fact that the deformation of pipe and ground was out-sync, on the assumption that stress and deformation characteristics of pipeline above the goaf were similar to that of a beam under uniform load with at both ends fixed. The pipeline allowable subsidence value was obtained by structural mechanics method. The other was elastic foundation beam on the assumption that the deformation of pipe and ground was in sync. The pipe was regarded as an elastic foundation beam, and the allowable subsidence of pipe was obtained. At last, comparing the pipeline allowable subsidence value with value of surface residual movement, conclusion that the pipeline would not be subjected to the hazards of mining subsidence was drawn.

With construction of long-distance pipeline in the complex geological mountain area in China, the urgent problem of how to control geological hazards induced by construction has arisen. This paper takes China-Myanmar Oil and Gas Pipeline Project construction as an example. The sweeping lines of pipeline construction, the approach of construction machinery, pipe trench excavation and construction, and the different working conditions are analyzed. Finally, the control methods are proposed for construction induced landslides, debris flow, rock fall and other typical geological disasters. The treatments are verified by the actual project with positive effects.

Some vertical retaining walls tend to bulge and even be destructed with the increase of active earth pressure, especially under the action of heavy rain. This paper designs a new, mountain-suitable inclined retaining wall that is applied in the geological disasters investigation/prevention planning of the Sichuan to East Gas Pipeline Engineering. The designed walled is used to effectively reduce active earth pressure behind the wall, and to guarantee the safe operation of the pipeline. According to the depth of the pipeline, we calculate the wall's stability and the wall designed force and discuss the height of the wall, taking the highly weathered slope along gas pipeline for example. This paper provides a practical technical support for the construction and safe operation of the Sichuan to East Gas Pipeline Project.

There would be numerous kinds of pressure pipes laid in cigarette manufactory. At the same time, huge amounts of pipe information need to be managed efficiently. However, traditional systems didn't consider the problems of inspection and repairing management for pipes. A digital management system for pressure pipe (PDMS) was designed to meet the inspection and repairing management requirements of a cigarette manufactory. The system included pipes' basic information management, inspection management and repairing management, to improve the safety management for pressure pipes. The system had two characters. Firstly, it could store the history record of thickness measurement for each pipe, and the trend of thickness change could be observed directly by curve. Secondly, according to the rules of pipe inspection, pipes need to be inspected periodically and production had to be halted while inspecting. Thus, the inspection early-warning was established to make sure the production was in normal operation. The system was applied to a cigarette manufactory, and the results obtained confirm serviceability of the system. It proves its value in managing pressure pipe, and it is easy to apply to other companies with huge numbers of pressure pipes.

Geological conditions are complex in the regions where China-Myanmar pipelines pass through, and lots of excavation and fill slopes were formed in the construction process, so these slopes should be studied and controlled. The slope stability factor is critical to designers and researchers in the slope engineering. However, the time factor is not considered in the calculation of the slope stability coefficient presently. In fact, the strength of rock and mechanical parameters are gradually reduced with time under stress, therefore the slope stability factor is ought to change with time correspondingly. In this paper, a function of the slope stability coefficient and time was established on the basis of the limit equilibrium equation, in which the time factor was introduced into the calculation of slope stability. Then, the theoretical calculation value was more suitable to the practical engineering result. In addition, this function was applied into the unstable slope evaluation of the China-Myanmar natural gas pipeline item, and it could provide a guarantee for the design of a full life cycle of pipeline.

Gas leakage can cause huge hazards to surrounding residents and buildings, with the ranges and degrees of these hazards depending on the concentration distribution of the leaking natural gas. This paper will investigate the velocity and concentration distribution of natural gas leakage jets. A methodology for computing the natural gas explosive volume and dangerous ranges in the leaking sites is developed according to basic hydromechanics. A practical case study of natural gas pipeline leakage is then analyzed by this methodology.

Oil and gas pipeline projects are mega-projects which are closely related to the national economy and the livelihood of people. They have high standards and strict requirements assuring safety and reliability. At present, China's total length of pipelines reaches up to 60,000 km, and the number keeps increasing quickly. Pipelines pass through different topographic and geological tectonic units, where they meet different kinds of geologic hazards. This paper discusses engineering problems connected with China's oil and gas pipelines as well as the geo-environment conditions and geo-hazard characteristics of the Sichuan-Shandong Gas-Pipeline Project (Hubei section). Solutions are offered using the comprehensive evaluation method of fuzzy mathematics and probabilistic analysis method. Geological hazard risk assessment is carried out and geological hazard grade and subarea are classified. In addition, the relevant protective countermeasures to geological hazards are suggested. Risk management and control strategies for geological hazard prevention during operation of oil and gas pipeline projects are discussed which provide a scientific basis of pipeline distribution, strike adjustment and control in geological hazard area.

Long distance natural gas transmission pipelines were designed to cross the western mountain area, where safety depends on the stability of related landslides. Anti-slide piles are among the most effective reinforcement measures in the field of landslide improvement. The paper presents a load-sharing pattern study of anti-slide piles reinforcement against landslide with pipeline crossing. Based on the case study of typical landslide and natural gas transmission pipeline, the mechanical model of landslide and pipeline was performed, from which the mechanical analysis on deformation of the pipeline is carried out. By using the numerical modeling method, the load-sharing pattern of anti-slide piles, sliding mass and pipeline was analyzed in detailed. The result shows that there is clearly destructive stress concentration occurring at the back part of the pipeline, and the setting of the anti-slide piles can drastically reduce the load-sharing ratio of the pipeline. That is the reason why the anti-slide piles can provide protection of the pipeline in the aspects of stress and deformation. The proper setting of anti-slide piles can improve the state of stress on the pipelines, which is the crucial explanation for the reinforcement mechanism of anti-slide piles.

The main methods of urban rainfall pipe flow routing are described on the basis of previous studies. Through the bench scale experiment and the comparative analysis of the methods, it concludes that the dynamic-wave and diffusion-wave method are adapted to the urban rainfall pipe flow routing under the condition of poor data and high accuracy requirements, while Muskingum method is suitable for the condition where accuracy requirements and data are moderate.

Multi-heat source co-heating networks have become the main trend of future development. However, the research for the optimization and dispatch of Multi-heat source co-heating networks is quite few in our country. Most multi-heat source heating networks still operated in extensive condition. Lacking of systematic and rational operation dispatch guidance, heating systems supply poor heating quality and consume high energy. Based on the theory of hydraulic calculation and Accessibility, a mathematical model for hydraulic optimal scheduling is established in this paper. It may supply the theoretical basis for optimal operation scheduling of realistic engineering heating network.

With the increasing of oil demand, the construction of oil pipeline is enlarging and the large oil pipeline network is developing. To instruct effectively oil pipeline to be operated safely, to control and optimize effectively oil pipeline operation condition, it is necessary to find out the change and characteristics of oil pipeline operation condition as well as its influence to the upstream operation and the downstream operation. Based on analyze the oil pipeline equations, this paper choose SPS software to simulate oil pipeline unsteady operation conditions. When the pump unit of a pump station is stared, the flow of this station will increase, the inlet pressure will fall and the outlet pressure will increase. When the pump unit of a pump station is stopped, the flow of this station will decrease, the inlet pressure will increase, and the outlet pressure will fall. When the block valve of a block valve station is closed, the flows of upstream and downstream will fall, the inlet pressure will increase, and the outlet pressure will fall. When the leak in oil pipeline is happening, the pressures of upstream and downstream will fall, the flow of upstream will increase and the flow of downstream will fall. These conclusions can help the managers and controllers of oil pipeline discovers matters and adjust operation scheme as well as perform emergency operation schemes.

Many projects of long-distance water transmission have been built to meet growing demand with adequate water quantity and quality. However, the constructed projects are paid more attention on the operation safety for the reason of single or double pipes transmitting water to cities as arteries. According to the user demand, it is essential to adjust flow of long-distance water transmission with gravity flow by the degree of plunger valve. The hydraulic status of the components in the projects, such as pipelines, plunger valves, air valves, pressure stabilizing tank are simulated by the numerical model with the theory of stable flow, and the status is analyzed by the rule of operation safety. There are three conditions for keeping the operation safety of long-distance water transmission in the stable flow. Firstly, the water pressure along the pipelines is below pressure bearing capacity leading to pipes broken. Secondly, the water pressure along the pipelines is higher than zero so as to avoid open channel flow. Thirdly, the water pressure is higher than 3m water head on the position of air valve for preventing leakage by the seal. The method of simulating and analyzing hydraulic status has applied in the long-distance water transmission project located in the northeast of China, and the result shows that the method could ensure the security and order in the process of operation.

In order to explore the accuracy of the water distribution network in its simplification process, with the three methods of branch collapsing, series pipe merging and parallel pipe merging, the DN300, DN500 and DN800 simplified network models were constructed under the different simplified conditions. Through comparing the pressure and flow accuracy between the original and these three simplified network models respectively, the result that the DN300 simplified model only can maintain the accuracy of the original network, but if the network is excessively simplified, its accuracy will be reduced seriously was obtained.

Dynamic pipe network hydraulic modeling is the realization of the municipal water supply network to optimize an effective means of scheduling and science operations. Pipe network modeling processes; the basic data collection, including flow and pressure points SCADA data; acquisition and importing of model work, is the key to establishing a precise model. GIS data in an urban pipeline network, for instance, creates a dynamic water supply network model. A detailed analysis of the operation, using WaterGEMS provides practical examples to establish a water supply network model based on SCADA data.

Hydraulic analysis of steady state conditions is typically used in the design and operation of gas networks. However, operational gas network systems are never in the steady state as demands and pressures vary with time. By comparison, transient analysis is more valuable and helpful for engineering design and operational management. The method of characteristics (MOC) is often used to analyze the transient flow of gas networks because it has clear physical concepts and employs rigorous mathematical analysis and precision in calculation. However, with MOC a small time step has to be included for an accurate result, which costs a lot of computing time. In this paper, it is shown that the method of characteristics with an inertial multiplier is capable of providing a numerical simulation of the transient flow in gas networks. After the inertial multiplier is established, then the transient flow for a gas network system is numerically simulated. Two simulation outcomes are compared, one using the method of characteristics and another the method of characteristics with an inertial multiplier. Results show that the time step can be selected flexibly and the computational speed can be reduced by means of the method of characteristics with an inertial multiplier. The method of characteristics with an inertial multiplier is more efficient for transient analysis of gas networks than the method of characteristics alone.

In a long distance pipeline, the trapped air usually resides at the dead ends and the segments of pipes with the high elevations because the air cannot exhaust smoothly. When the pump shuts off or the valve is closed suddenly, the water hammer with gas-liquid two-phase flow will occur. The pressure resulting from the gas-liquid two-phase transient flow will be much bigger than that from the general water hammer. It is one of the major factors to result in pipe burst. The objective of this paper is to study the gas-liquid two phase transient flow in the pressure pipeline. The research achievement is applied in an actual engineering project. Firstly, the control equations of the gas-liquid two phase transient flow in pressure pipelines are presented based on the gas-liquid two phase flow theory and computational fluid dynamics. Then, by means of volume of fluid (VOF) model, the flow field around the trapped air in pipelines is numerical simulated and analyzed on the stages of water filling and pump failure. The pressure fluctuation around the trapped air is obtained. Finally, the research achievement is applied to an actual long distance pipeline. The results show that the VOF model could effectively simulate the flow fields of the gas-liquid two phase transient flow. On the stage of water filling, the maximum pressure head decreases with the increase of the valve opening duration. When the pump shuts off suddenly, the maximum pressure head rises up with the increase of the pipe slope in which the trapped air exists.

The accuracy of water consumption prediction has a direct effect on the practicality of optimal operation and control in a water distribution network system. In this paper, Support Vector Machine (SVM) was applied to conduct simulation training for hourly water consumption data (over a period of 11 months) which had been processed by fuzzy information granulation method, and water consumption for the following month was predicted. First, the maximum hourly water consumption was extracted from the previous 11 months' water consumption. Then every seven data (a week) were transformed to a triangle fuzzy particle. Three parameters of the triangle fuzzy particle, Low, R, and Up were defined as the minimum change (Low), the average change (R) and the maximum change (Up) of the maximum water consumption during one week. Finally, SVM was used to predict these 3 parameters and the maximum hourly water consumption. In order to solve the SVM, problems occurred while adjusting related parameters, and optimization selection via genetic algorithm was proposed. The results in actual application indicated that this model had faster speed, higher precision and practicality.

Owing to high pour-point of most waxy crude oil in China, if the wall temperature is below the wax precipitation point through pipeline transportation, wax crystal will appear and deposit with the other components of crude oil on the wall together. This process is commonly known as "wax precipitation". It is the widely existing problem of wax deposition in pipelines during transportation of waxy crude oil. This phenomenon leads to many problems such as pipe plugging, production rate decreasing, pressure drop increasing, fiction increasing and so forth. In the non-equilibrium thermodynamics, wax deposition is a complex coupling irreversible process with diffusion, heat transfer and fluid flow and phase change together. To start with the main factor of several stages, such as dissolution, precipitation, diffusion, deposition and ablation of wax, the physical model of non-equilibrium thermodynamics process on wax deposition in pipeline transportation process was established. Then combined with fugacity and activity coefficients, enthalpy change and entropy change of phase transition process and solid-liquid phase equilibrium model in atmospheric pressure are deduced, the pipeline operation parameters on the effect of wax deposition law in transportation pipeline is explored, thus the theoretical foundation can be provided to make further research on wax deposition with non-equilibrium thermodynamics.

Taking W-zone in a city of North China as an example to which setup hydraulic model. Using GIS data to establish water distribution network topology. According to the nearest pipe method and unit line method, the flow of the pipe network node is distributed. Using genetic algorithm to calibrate C-factor. According to hydraulic calculation and the results, the monitoring value and simulation value of water distribution network node pressure are within 3 meters, the monitoring value and simulation value of pipeline flow are within 5%. Results show that the genetic algorithm calibration is applicable to solve the complicated and enormous water distribution system.

The performance curve of pump reveals the relationship between the pressure and the flow rate, yet the constitutive equation of fluid reveals the relationship between the shear stress and the shear rate. So it is important to investigate the relationship between the effective shear rate and the flow rate in pipeline. For pipeline transporting viscoplastic fluid, a zone without shear rate may exist in the pipe center, and that will make the relationship between the effective shear rate and the flow rate obviously different from pipeline transporting fluid without yield stress. Based on the analysis of laminar flow of viscoplastic fluid in pipeline, an implicit equation to reveal the relationship between the effective shear rate and the flow rate was derived, by which numerical simulation and analysis for pipe flow of different types of viscoplastic fluids in different conditions were carried out. For pipeline transporting viscoplastic fluids under a constant flow rate, the effective shear rate increases with the increase of the yield stress of fluid, and decrease with the increase of the consistency and the rheological index of fluid and the inside diameter of pipeline. For pipeline transporting viscoplastic fluids with thixotropy nature, the effective shear rate will also decrease with time, yet tend to stable.

With increasing concerns about global warming, energy conservation and emission reduction have become a growing consensus and a global priority towards sustainability. As a fundamental infrastructure to sustain human activities and civil development, wastewater pipeline networks are receiving attention in the context of population growth and industrial expansion in urban areas. It is therefore quite challenging to analyze the environmental impact of wastewater pipeline projects and explore effective construction methods and strategies. A model to estimate CO₂ emissions resulting from a typical wastewater pipeline project was developed based on life cycle theory. Wastewater pipeline construction emissions are divided into three categories: 1) material manufacture; 2) material transportation; and 3) pipe installation. The methodology for estimating CO₂ emissions is demonstrated using a wastewater pipeline project in Suzhou, China. The results concluded that the materials consumed most by weight are sand, cement, cohesive brick, gravel, limestone, and UPVC pipe. It was also found that most of the emissions from material manufacturing were from UPVC pipe, which provide an insight into revealing the elements with significant reduction potential. CO₂ emissions released by producing material accounted for approximately 87% of total emissions, while the emissions released in the other two categories were less than 13%. The unit CO₂ emission of the studied wastewater pipeline construction project using traditional open-cut methods was 516.59 t CO₂/km. This provides a reference for estimating CO₂ emissions resulting from other wastewater pipeline projects.

Based on the framework of station integrity management, according to the maintenance management of rotating machinery equipment on station, this paper illustrated the theory and practice method of reliability centered maintenance (RCM). Combined with the practical situation of station, it described the implementation procedure on situation, analyzed the failure mode of pump, and made maintenance plan to the failure model of different risk levels. RCM could improve equipment running status, extend operation life, and control for maintenance cost saving effectively.

Combining a six-step cycle integrity management mode in PetroChina Pipeline company with an integrity management program, this paper sorts out the business relationship of pipeline integrity management and achieves the design scheme of closed-loop management. The design scheme fixed in the Pipeline Integrity Management System (PIS) by information means realizes the integrity of business standardization and information management.

According to the operating characteristics of gas pipeline during tightness inspection, the partial differential equation model is established for a single point leak of gas distribution networks in pressure testing. Based on inversion of differential equations boundary conditions, the localization of leak location and leak intensity is transformed into inverse problems about partial differential equations, and then deriving mathematical expressions of leak location, leak intensity attenuation coefficient and leakage coefficient by using Laplace transform. the methods of numerical calculation is constructed by applying the principle of compressed image, at last an example is analyzed and calculated, the analysis of results shows that the calculated values better match with the actual situation, and essentially meet the request of leak detection in pressure test of gas transmission and distribution pipeline systems.

The natural gas pipeline leak can cause major accidents and hazards. It is crucial to detect a leak timely and to determine the leakage point. In this paper, domestic and international long-distance pipeline leak detection and location technology in recent years, are introduced scientifically and pointed out the advantages and disadvantages of each method. With the development of oil and natural gas, pipeline transportation is becoming increasingly important in the national economy. In the meantime, to acquire a reliable and economic leak location method is extremely essential. This article also makes a systematic exposition for possible development of the leak detection and location technology in the near future.

Accumulation of solids in storm sewers results in not only a loss of flow-carrying capacity, but also corrosion of drainage pipes and pollution of receiving water bodies. This paper presents the correlation of sewer sediments' particle size with content of organic matter, total phosphorus (TP) and total nitrogen (TN) respectively in an urban area of Guangzhou. The result shows that the sediments of the researched areas can be divided into two types. Type One mainly consists of gravel, sand, and a little decayed animal matter. branches or leaves. Type Two mainly consists of soil, sand, and a large amount of decayed animal matter, branches, or leaves. For Type One, smaller particles contain greater amounts of pollutant, while for Type Two, most of the pollutants are gathered in the coarser particles. In addition, the particle that contains the largest content of organic matter also contains the largest number of TN.

Leakage is one of the main problems faced by many pipeline industries, such as water supply and gas transmission systems. For its prominent capability of on-line monitoring the singular signals, acoustic emission (AE) technique has been considered as one of the most potential manners for pipeline leak detection. As a kind of continuous AE signals, leak signals are usually processed with cross-correlation method. However, due to the multi-modes and dispersion nature of AE wave propagating in pipeline, the traditional cross-correlation analysis does not perform well in practice. This paper presents an improved cross-correlation algorithm for high-precision pipeline leak detection based on wavelet transform and energy feature extraction. Both energy and frequency features of AE signals are taken into consideration to determine the time delay for leak location. A series of numerical simulations are conducted and AE signals measured in-situ is analyzed based on the proposed method. The results show that the improved method can achieve higher precision of the identification for signal similarity and time delay, especially when the continuous AE signals are affected by various disturbances and noises.

With the growth of pipe's age, aging, corrosion, vandalism, and other causes make oil pipelines leak; and these accidents have often occurred. It not only causes much economic loss, but also seriously damages the ecological environment. Among the accidents of oil pipeline leakage, flange leakage accounts for a higher proportion. So, it is necessary to study the flange leakage. First, by studying the causes of flange leakage totally; putting forward several fast leaking stoppage methods about the flange leakage, and by Comparing and analyzing these methods on their equipment, operation, security and other aspects. Finally, draw a conclusion that it can plug the oil pipeline flange more excellent, and introduce the Inject-sealant plugging under pressure detailedly.

To detect the micro-leakage of long distance gas pipeline, this paper presents a novel method based on precise optic fiber sensor and optical multiplexing technology. The precise optic fiber sensors based on interferometer are designed and placed on the surface of gas pipeline to detect the stress wave, which is generated by the gas-structure coupling and propagating alone the pipeline. The optic fiber sensors were multiplexed by three optic fibers, and one optic fiber was the sensor activation channel. The others werestress wave signal transmission channels. The experiment results of test field showed that the stress wave could be detected by the optical fiber sensor, which was apart from the leakage point 500m. The longest distance between the first and the last sensor was 36km, and 32 sensors could be multiplexed simultaneously.

The way of transport pipeline occupies an important place by its own unique advantages in the national economy. However, due to various reasons, the leakage accident of pipeline occurred frequently. Not only does it cause the loss of resources and environmental pollution, but it also brings the huge damage of property. This paper analyzes the principles and methods of position which base on negative pressure wave, and a comprehensive platform of pipeline leakage detection is established which based on the negative pressure wave. Analyzing the present research of pipeline leak detection and localization technology in detail. To the leak detection of heating oil pipeline, the problems which impact accurate position are analyzed in detail. The GPS system is used to eliminate the influence of mistiming. For characteristics of heating crude oil which result in the variation of velocity, using Rombery algorithm to solve the method how to position when the velocity of the transient negative pressure wave changes along the tube.

With the wide availability of natural gas, a lot of gas pipelines are laid. But because of the factors of nature and human, the leakage accident of pipe occurred frequently. This paper introduces the principle of pipeline leaking detection which based on the infrasound wave and expounds the advantage of the infrasound wave which used on the detection of leaking pipeline. The time lag is determined by using the synchronal method of GPS time, and analyzing the factors which can influence the propagation speed of sound waves and it also introduces the structure of the experimental platform, and explains the hardware design of leak detection system. The whole experiment uses the sensor of infrasound wave which invented by the Chinese academy of sciences realized the data acquisition and real-time monitoring of gas transmission pipeline. It describes the composition of software systems which need to achieve the main functions of the data import, digital filtering and data storage.

As a clean and efficient energy, natural gas is increasingly noticed at home and abroad. Pipeline, being the major means to transmit natural gas, its operation safety is particularly important Because of the inflammable and explosive characteristics of natural gas. This paper proposes a method of extracting leakage gas directly and testing using semi-penetration pipe and realizing real-time on-line inspection and positioning of the pipeline leakage; and it analyzes the profound importance of the leak detection technology as the construction of gas pipeline network of the rapid develops; and it also analyzes and evaluates the leak detection technology in recent years at home and abroad, and it eventually succeeds in working out the rationality and adaptability of this leak detection method.

The seismic design of long-distance pipelines is very important because the earthquake could lead to serious damages to pipelines and bring secondary disasters or major economic losses. The destruction of the seismic action on the pipelines can be divided into two categories: one is the strong ground motion, the other is the permanent deformation of the ground, including fault moving out of place, liquefaction of sand, landslide, and so on. The different destruction reasons would affect the long-distance pipelines in different ways. In this paper, the effect was analyzed by giving examples from home and abroad. The impact of the earthquake to pipelines with different seismic design parameters is different as also, the paper carried out the relative study using the finite element knowledge, the seismic design parameters being researched including seismic peak ground acceleration , pipe diameter, pipeline depth and the type of backfill for buried pipelines (soil density, friction coefficient, overburden compaction multiplier), the study acquired the corresponding distribution relationships of the above parameters with pipe stress in earthquake; Finally, the paper raised the seismic design measures for long-distance pipelines combine with the research results, the study of this paper has positive significance for the seismic design of long-distance pipelines.

This paper proposes a systematic approach to design a buried cross-country steel pipeline for oil transportation, based on limit states of the pipeline in operation. Yield and buckling due to primary loads and secondary loads are considered in the limit state design. A procedure to evaluate limit states in accordance with stress and strain criteria is proposed when the pipeline is applied with factored loads. The evaluated limits include the maximum stress limit for FEA with beam-elements and the equivalent stress and strain limit for FEA with 3D solid elements. The soil conditions along the pipeline are classified into three different types. Soil is represented by discrete bilinear springs for the beam-element pipeline model and represented by extended Drucker-Prager model for the 3D solid element model. The sensitivities of the limit states to the soil conditions and pipeline bend parameters were studied. Mitigation measures are taken to make the pipeline meet the proposed limit state evaluation criteria. The cost and constructibility are taken into account to expand the beam-element model to the 3D solid element model.

A large diameter steel pipe was tested under static soil loads at the Center for Underground Infrastructure Research and Education (CUIRE) laboratory at UT Arlington. The 6-m, 1830-mm nominal diameter steel pipe was placed inside a concrete load cell and backfilled with lime stabilized native clay soils obtained from the Integrated Pipeline (IPL) project site in Texas. The properties of untreated and lime stabilized clayey backfill soil was first determined through the laboratory tests. Lime stabilized soil was used as bedding and embedment up to springline of the pipe. Untreated clayey backfill soil was placed above the springline up to one foot above the crown of the pipe. 8 ft of pea gravel was placed above untreated soil to simulate dead load of cover. Vertical loads at crown and bottom of the pipe and horizontal loads at the springline of the pipe were recorded. Also, changes in vertical as well as horizontal diameters of the pipe were measured during and after installation of the pipe. The purpose of the test was to study interaction of the large diameter steel pipe with lime treated native backfill and calibrate the related Finite Element Model (FEM). This paper describes details of the test and presents the obtained results obtained. Based on the results of this and other tests and related Finite Element Models will be calibrated.

The earthquake damage of buried pipelines can be classified as being either due to seismic wave propagation or large permanent ground deformation like fault landslides, liquefaction, etc. More typically, pipeline damage is due to the large permanent ground displacement. To resist the large displacement induced by fault motion or liquefaction, an isolation device is designed in this paper. On the basis of theoretical analysis and analytical simulation based on finite element analysis, the stress and deformation of buried pipeline under different large ground displacement are analyzed. The interface characteristics of pipe-soil system to seismic wave is also discussed herein. The isolation parameters affecting the seismic response of pipeline with ground displacement are discussed in details.

The crude oil tank design methods presented in various codes are usually based on insulation, especially in China. However, the insulation of tank and wall cooling may be contradictory since the insulation of tank wall may prevent the wall cooling. Once the tank on fire, if the cooling water cannot effectively play the cooling role, the burning tank may collapse and the heat radiation from the fire could threaten tanks nearby. The design of insulation for crude oil tank should account for both fire cooling and insulation. In insulation, the issues related are to prevent heat loss as much as possible, and make oil temperature maintain at a certain range. Inadequate flow of cooling water often causes the nearby tanks to absorb a large number of radiant heats, and largely increase the fire risks. Consequently, in order to eliminate hidden dangers to protect the safety of tank group, the cooling water flow and the thermal resistance of insulation should be considered together. In recent years, a number of projects have been funded to develop some crude oil reserve bases in China. In this work, the different water requirements between Chinese codes and others is pointed out firstly. Then the control factors of the cooling water flow and the thermal resistance of insulation are examined. Then the calculational model of fire cooling water and insulation on crude oil tank is built. Obviously the insulation may reduce fire cooling impact on crude oil tanks. At last, a rude water requirement results and future work are discussed. Based on this paper, the tank manager can be aware of the potential fire threaten tank group and able to choose to do something in advance for prevention and remediation. It is believed that the approach to the calculational model of fire cooling and insulation presented in this paper may lay the initial basis for tank fire prevention.

There are many oil fields in the west of the No. 9 Oil Production Company in Daqing. And the fields have a small quantity of oil wells. These wells have low output, a long distance between each other, and all alone one another. Now there are many problems and contradiction in the oil field surface pipeline system. On the one hand, the old pipeline system needs adjustment, rebuilding, and planning as a whole, so as to improve its running load rate and adaptive ability, on the other hand in some areas, many new blocks are put into production constantly, which makes the current pipeline's capacity unable to handle the increased rate flow. To satisfy the demand of the practice production, we developed the pipeline system optimization software for the No. 9 Oil Production Company of Daqing . The software is designed to offer the guidance for the sound investment, safety production and continuous development of the oil field. Pipeline system of the No. 9 Oil Production Company was optimized and adjusted by using this optimization software. Newly developed blocks, that is to say Talaha Block, its produced liquid should be gathered by drawing to Yingyi transfer station for stripping operation, then transported to Puxi united station, and arrives at Longyi united station by way of Guyi united station. Long'er united station is turned into a transfer station from previous dehydration facility. Its wet crude oil is transported to Longyi united station to dehydrate, and its pipeline of transporting purified oil is ceased.

The long distance gas pipeline compressor is a large-scale energy consumption equipment, the operation energy consumption of compressor station account for more than 70% of the operation energy consumption of the gas pipeline system. In the practical operation, gas pipeline and compressor station is a unity. The operating parameters are interrelated, affected by factors such as changes in production capacity of gas source, seasonal fluctuation of user gas consumption and equipment service or failure. The operating conditions for pipelines are constantly changing over time, so the compressor unit may be at low-efficiency resulting in the rise in unit of gas energy consumption or gas pressure and flow rate less than the set values. On the basis of the security analysis in the joint operation of the pipelines, equipment components, Selecting the operating mode and status of the compressor unit, as well as the operating parameters of the gas stations (compressor stations, injection points, outlet points, the pipeline intersections, etc) as the optimization variables. Taking the operation energy consumption of pipe network as the objective function, establish the optimization model of energy-saving operation of long distance gas pipeline, and then put forward the model solution method based on bundle projection subgradient method combined with Lagrange multiplier. Through the computation and analysis of actual operation scheme for pipelines, the results show that it effectively reduce the operating energy consumption of the entire gas pipeline system.

Reinforced thermoplastic pipe (RTP) is an innovative application in the oil & gas industry. The mechanical property of RTP under axial loads is a significant parameter for the popularization of RTP. This paper focuses on the experimental and numerical research on the behavior of RTP under axial loads. First, prototype tests, including axial tensile tests and compressive tests, are conducted; and then, a nonlinear finite element model employing solid elements and truss elements is created. In this ABAQUS model, the material nonlinearity is taken into account. The prototype tests reveal the fundamental mechanical properties of RTP under axial loads. The numerical models are validated against the generated experimental data, including load-extension relationship, load-shortening relationship, yielding load under tension, collapse load under compression, and failure mode. Close agreement can be found between the numerical results and the experimental results, so the finite element model in this paper can be regarded as feasible to analyze the mechanical properties of RPT and similar structures.

The collapse of RTP under uniform external hydrostatic pressure is investigated in this paper. Extended from the model initially proposed by Kyriakides and his co-workers, a 2D theoretical model which takes into account the mean radius change, the wall thickness change, transverse shear deformation, and pre-buckling deformation is further developed. The reinforced layers, consisting of PE and aramid strands, are taken as homogeneous layers and equivalent stiffness method is used to get their mechanical parameters. J2 flow theory with isotropic hardening is adopted to model the plastic property of the material. By means of numerical calculation, the ovalization-pressure curve and ovalization-strain curve of RTP is presented. To confirm the accuracy of the theoretical model, numerical simulation is conducted using a 2D finite element model within the framework of ABAQUS. It is found that the results obtained by theoretical method and finite element method show good agreement. Finally, the effects of several parameters are studied by use of the theoretical model and useful conclusions are drawn.

With the rapid development of urbanization, the current urban underground Pipeline Network Construction is becoming more and more complicated and highly demanding, and the pipeline location accuracy draws an increasing attention. Therefore, the research on the electromagnetic wave propagation in stratum is gaining remarkable significance. By applying Wave Theory of Electromagnetic Field, this paper studies on the electromagnetic signals' propagation particularity and attenuation regularity in the Horizontal Directional Drilling stratum and summarizes that the attenuation of electromagnetic signals is decided by two parameters: the stratum medium's electric conductivity σ and the electromagnetic signals' working frequency ƒ; a series of contrastive analysis of curves indicates that when the stratum's electric conductivity σ < 0.1S/m,working frequency ƒ between 1 ~ 20KHz, Horizontal Directional Drilling guiding construction at the depth of about 20m in stratum, the magnitude strength ratio is above 36.8% after electromagnetic signals' attenuation, which is great beneficial to the emission and acceptance electromagnetic signals in the stratum. This research results provide the fundamental theoretical basis and guideline for the design, research and application of electromagnetic location depth measuring in the guiding system.

At present, China has entered into a large-scale development period in the field of coal bed methane (CBM), the technical characteristics of which are low production, low pressure and low permeability, with the result that CBM surface gathering pipeline networks are extremely complex. Domestic exploitation and design of CBM fields are largely based on the mature engineering design experience of Sulige field, and needs further improvement. There are no appropriate standards or specifications on the gathering and processing techniques of CBM. Existing problems are primarily unreasonable pipeline network layout and parameters, large project investment and high energy consumption. To take full advantage of CBM energy, reduce pipeline network investment and achieve low cost exploitation, analysis of the characteristics of CBM gathering technology and adaptability of different gathering pipeline network forms under different terrains should be made of. Apply hierarchical optimization method, which divided to layout optimization and parameter optimization, to study branched pipeline network optimization problems, propose measures to increase the transmission radius and provide technical support for CBM gathering engineering.

Suspension pipeline bridge is a significant pipeline acrossing type. In particular.. when the pipeline goes through mountain and canyon terrain, suspension pipeline bridge is often used. For parallel pipelines of the oil and gas, shared across the project is inevitable. In this paper, it takes a oil and gas shared suspension pipeline bridge which the main span is 360 meters as the research object, use the finite element numerical simulation method to analyze the dynamic response under seismic loads. According to the analysis results, it determines the weak link of the structure under the seismic and evaluates seismic performance of the structure.

Underground pipeline serves as the "lifeline of the city" and is closely related to people's everyday life. Both rigid and flexible material are used in the production of these pipes; the former includes concrete and clay and the latter includes unplasticised polyvinyl chloride (UPVC) and polyethylene. Due to the serious results the pipeline malfunction may bring about, it is of great importance for non-excavated pipeline inspection to be conducted. Current inspection methods include: closed-circuit television (CCTV) inspection, sonic distance measurement, and quick view method. An overview of the features of both rigid and flexible pipes as well as the current methods for underground pipeline condition assessments is presented in this paper. Besides, an application of closed-circuit television (CCTV) inspection method on water pipelines is reported. The water pipes, called double wall corrugated pipes, are made of high-density polyethylene (HDPE) material. Problems detected during the inspection are listed and factors contributing to the pipe deterioration are categorized into three aspects, namely, material factor, construction features and local external factors. General suggestions are made regarding possible directions for further research at the end of this paper.

Symmetrical push-pull low circle fatigue tests have been performed on high-strain X80 line pipe material. Micro-analysis has been performed for deformation mechanism as well. Results show that X80 high-strain line pipe material exhibited a higher ductility and long low-circle fatigue life. Cyclic softening is observed at low strain amplitude of 0.4% and 0.6%, however, cyclic softening occurred after slight cyclic hardening at high strain amplitude of 1.0%, 1.2% and 1.4%. Generally, Cyclic response curves show that the cyclic softening occurred at all strains amplitude (0.4%~1.4%). Fractography analysis suggests that transgranular fracture with well-developed fatigue striations and obvious second crack is the predominant failure mode. The amount of second cracks is much fewer deformed in high-strain X80 line pipe material than that in conventional X80 line pipe material. TEM examination reveals that the primary deformation mode of two kinds of material was dislocation slipping. Abundant dislocation glide bands and dislocation cells are formed at grain boundary as strain amplitude increased. Deformation in ferrite has been suppressed and formation of dislocation cell inside the ferrite has been postponed due to large content of M/A constituent.

In terms of Biot's dynamic theory, the multi-polar coordinate and complex function are used to put forward an approximate analysis method for scattering and dynamic stress concentration of harmonic plane SV-waves around a circular unlined pipeline in half space of saturated soil. Here, a circular cavity with large radius is used to replace the straight boundary of the half space of saturated soil . By using the theory of Helmholtz, the general solutions of the Biot's wave functions are given, and a system of infinite linear algebraic equations for the problem studied in this paper are generated by means of the complex series expansion technology and the boundary conditions of the solid matrix and the fluid. This research also presents the variation of the coefficient of dynamic stress concentration at boundaries of the unlined pipeline with different parameter conditions. The results of the given examples indicate that the method used in this paper is useful and efficient to the scattering and dynamic stress concentration of harmonic plane SV-wave around the Unlined Pipeline in a Half-space of Saturated Soil.

Research studies examining buried pipes cannot rely on computational work alone, and physical experiments are needed for credible evaluation of buried pipe performance at service and ultimate loads. Specialized testing facilities are described which can be used to undertake buried pipe experiments on structures up to 10 m span at shallow cover, and pipes of 0.6 m diameter or less up to 1000 kPa overburden pressure (about 50 m burial). The capabilities include service load testing under real vehicles, and testing to ultimate limit states under simulated axle loads of up to 2000 kN (about 9 times the normal service load for a tandem axle design truck). Use of the facility is briefly illustrated through reference to six different projects on pipes and culverts installed using conventional and trenchless construction techniques.

It is not easy to get accurate and consistent on simulation of gas flow in a loop pipeline network with multiple gas sources and other components such as valves and tanks, etc. Accordingly, a novel Object-Oriented (OO) method based on is proposed to provide a total solution using hydraulic and thermodynamic computation in a loop pipeline network with multiple sources. An analysis of a practical engineering pipeline case in China proved how the proposed method can be used in gas steady/transient flow simulation, and the results agree with measurement data.

With the development of the computer, the finite element method has been widely used as an effective numerical method for the analysis and design of underground structures, including calculation of stress and strain. This paper demonstrates application of the ANSYS finite element method for stress analysis of an underground pipe structure as an alternative to the traditional method. The results more reasonably reflect the actual situation, providing an improved design procedure, helping avoid pipe wear and breakage. The glassfiber reinforced plastics (GRP) pipeline is analyzed as an example, illustrating the basic finite element method, including modeling, and specification of the boundary conditions and applied loads. The results are generally consistent with that of the traditional method, using the CECS190 standard, based on the maximum long-term vertical deformation.

In a subsea engineering project, the pipeline structural component known as a bulkhead helps to limit loads and is an important consideration when preparing analytical design based on pressure vessel standards. The usual procedure and method of calculation for limit load is introduced with finite element software. Three kinds of load applications are considered. In each case, the displacement-load curve of location with the maximum strain is obtained under different load applications based on when the limit bending moment occurs and tension load is reached. The results prove the effectiveness and suitability for subsea pipeline component and the process and method can be spreaded to the design and evaluation of similar pipeline structures.

Pigging is one of the basic measures used to guarantee long-term pipeline safety during transmission, and is often used after pressure testing and in normal working conditions. In China most of the natural gas pipelines are distributed in hills, mountains and other large areas, but terrain height has no effect. Due to the pipeline stress factors on pipe walls thought to be related to the cleaning process involved in the gas pipeline stress model, this paper offers an appropriate pigging transient model in order to simulate the stress on pipeline walls more accurately, analyze the effects of pigging for gas transmission pipeline quantitatively and offer guidance in the furtherance of pigging operation knowledge.

Tempering test of X80 induction bends with diameter of 1219 mm, thickness of 22 mm, are performed at different temperature. and then the tensile tests. CVN tests, chemical analysis and microstructure examination are tested on base metal and welding of X80 induction bends, which is tempered at different temperature. The results showed that the strength and toughness of X80 induction bends has been improved by. temper. And the best match of strength and toughness are obtained when temper temperature is 550°C.

By simplifying the boundary conditions of natural gas in double-skin pipeline, standard k-ε turbulent model and CFD method were applied to analyze the characteristics of leakage diffusion, the leakage of diffusion process was simulated, which pressures were 0.6 MPa, 1.0 MPa and1.6 MPa. Results shows that leakage speed and temperature of outer pipe face increases rapidly and temperature reach maximum at the leakage time of 3s. With increasing distance from leakage inlet, temperature and velocity field raises and loared as shock wave.

Buried pipeline is a kind of engineering equipment, with the increase of the pipeline working time, buried pipeline spill caused by the defects, that corrosion, abrasion and other inevitable factors occur. With the study of leakage numerical simulation in buried pipelines, we can analyze the influence that single phase-flow, multiphase flow and phase transition of crude oil makes on leakage process, and determine the impact of the leak under the various factors on the earth temperature field to provide a theoretical basis for the rapid repair of the thermal infrared detection and buried pipelines. The results show that different penetration process and different thermal conductivities lead to different trends of surface temperature under the two kinds of leak process conditions; Regardless of the phase transition of crude oil and considering phase transition of crude oil leakage, basically the penetration process and surface temperature trends are the same, however, it releases latent heat of solidification during oil phase change process. Therefore, consider the surface temperature trends in the oil phase change, multiphase flow leakage process lags behind considering the oil phase change, multiphase flow leakage in the process of surface temperature trends. The conclusions of this article are for guidance buried oil pipeline leak infrared imaging detection and crude oil contaminated soil remediation reference.

Wax crystal in waxy crude oil precipitates gradually with temperature drop after shutdown. Congelation accident occurs and leads to heavy losses when the oil forms a intense structure. It is necessary to conduct identification of congelation risk, analyze various influencing factors of congelation accident and establish the fault tree of congelation risk for the pipeline operation safety. In accordance with the fact there are two immediate causes of influencing congelation failure. One is the pipeline flux can not be stable in limited time after restarting and the other is the restarting pressure is greater than the maximum allowed operation pressure of pipeline. Takeing the "congelation failure" as top event, and also combining with the influencing factors of pipeline failure, the fault tree was established in the paper. On the basis of the minimal cut sets principle, qualitative analysis of the fault tree was conducted. Therefore the main factors of pipeline failure are obtained, including low throughput in operation, low supporting pressure capacity of pipeline, wax deposition on pipe wall and overlong shutdown time. Finally, based on above mentioned elements, some improving measures can be provided to guide and support for better accident treatment, planned overhaul and scientific management.

The waves load was calculated for the safety of floating pipeline, as it was the main load for a pipeline in the sea. Floating pipe extended from offshore to the deep sea, and its corresponding water depth varied greatly. Thus, the single wave theory was not reliable. In this study, the Morison equation was used in calculation with the help of solitary wave theory, Stokes wave theory and Airy wave theory. The water depth was divided into shallow waters, transition zone and deep water area, according to the water depth, wave height and circle time. The software was employed to calculate the pipe load under different water depths under the supposed sea conditions. The wave load was revised based on reduction conditions and the wave force angles.

This paper analyzes the critical suspended length of an inshore pipeline which is anchored straight on the seabed. Pipe suspended length determines the static load and dynamic response of the pipe, playing an important role in the stability of submarine pipeline. Thus, with the CAM static theorem, the allowable suspended length of the pipeline is calculated. The results show that the suspended length due to seabed depressions can be far longer than that due to submarine obstacles. Also, study for the vortex-induced vibration (VIV) of the pipeline is carried out to avoid that resonance vibration happens between pipeline and wave; the allowable range of the pipe span is compute with the CAM dynamic theorem. To get a more reasonable critical suspended length, two kinds of finite element span models are built according to the location of pipe span. With the software ANSYS, the models are analyzed under wave conditions. The results reveal that the critical suspended lengths differ in the two models; the location and value of the biggest flexural stress on the pipeline vary according to the anchor span (distance between two anchors).

The Marston soil-pressure mode is used to calculate the top pressure of the pipe subjected to the surface load. In the calculation, the load caused by soil weight is deal with as the pipe buried depth. The Spangler-Iowa method is adopted to calculate the strain and stress of the pipe respectively with or without internal pressure. One case of pipe subjected to the surface load of the Western Pipeline Company was chosen for the instance analysis calculation. The results show that he strain and stress of the pipe is larger and the situation of the pipe is dangerous when the pipeline is without internal pressure and the strain and stress is smaller when the pipe with the internal pressure. The reason is that the internal pressure improves the stiffness of the pipe in the round direction.

During the drilling of horizontal wells, extended reach directional wells and ultra-deep directional wells, there is always a long drilling period after the cementing of intermediate casing. The rotation, tripping, flexing by bit weight and transverse vibration of the drilling pipes causes casing wear during this period which lowers the internal pressure strength and the collapsing strength of casing. At a certain casing grade, the drilling parameters that affect casing wear mainly includes rotary speed, rate of penetration (ROP), mud density, mud type, and bottom hole assembly. Until now, quantitative influences of each important factor on casing wear have not been studied. The authors addressed this need by studying the XG-X well, and the results indicate that rotary speed and ROP affect e wear the most. The wear of the well's casing at different rotary speeds and different rates of penetration was computed and the relationship of ROP to rotary speed to wear shows that the parameters are controllable within a certain scope. The two drilling parameters can be rationally selected to reduce the wearing during the actual drilling process so as to lengthen casing life and oil well service life.

For long-term in-service offshore oil pipelines, health diagnostic technology is a significant task to be studied and resolved. Because the pipeline serves for a long term in bad marine environment and the damages caused by the same are invisible and special, there are many uncertain factors. Thus, it is very important to adopt a series of health diagnosis methods to protect the in-service offshore oil pipeline from damages. Combined with the practical situations of some in-service offshore oil pipeline in Philippines, analyses on chemical composites and mechanical properties have been made for pipe materials. With the utilization of PIT (Pipeline Inspection Tool) method from RTD Company, a global leader in non-destructive testing, the residual wall thickness has been measured and the residual strength of the pipeline also has been confirmed according to DNV-RP-F101. Predicting the remaining service life of offshore oil pipelines provides technical support for further project operations. The research on health diagnosis technology for in-service offshore pipelines is prospective and has significant importance for evaluation of pipeline.

The principles of buried pipeline non-excavation detection and the advantages of using the torsional guided wave of T (0,1) mode detection technology are described. By using the finite element code ANSYS, a finite element model with circumferentially oriented through-thickness cracks of axial widths was built to simulate crack detection in pipe using a torsional guided wave. The crack was defined by the method of removing elements and the torsional guided wave of T (0,1) mode -input simulated by prescribing axial displacements at one end of pipe, which was also the position of receiving the echo wave from the crack location. The results of numerical simulation showed that a single crack position could be accurately identified. A British guided wave's Wavemaker G3 Pipe Screening System was used which receives torsional guided waves based on the piezoelectric effect. Using the Wavemaker G3 Pipe Screening System allowed detection of defects in the pipe experiment. The results showed excellent agreement among the numerical simulations and experiments conducted by the former investigators.

Communication between the inner and outer of the subsea pipeline is the key technique for the smart plugging system. For this technique, a theoretical calculation method and results for the penetration frequency centering on the choice of Extremely Low Frequency (ELF) electromagnetic communication wave is put forward. Meanwhile a simulated experiment in the lab is conducted to verify the theoretical calculation results. It is demonstrated that the optimal frequency band is 9.27~37.037 Hz in theory when the ELF electromagnetic wave penetrates the seawater. The result of test is 10~30 Hz with the maximum induction times 20 Hz which fits the theoretical results closely. Based on the research the overall design of ELF electromagnetic communication is presented and preliminary debug is conducted successfully.

As a safe and economical method the pipeline is widely used to transport the oil and gas. At present, most of serious pipeline accidents are the artificial damages. The traditional leakage detection methods only infer the leakages by analyzing the parameters. The sensitivities are low and the leakage warning exclusively arrives after the leakage. The urgent problem is to detect the intrusions and locate the threat position. For this reason, we studied and developed a novel pipeline security monitoring and pre-warning system based on multi-seismic sensors. The system consists of many seismic geophones and data acquisition modules which are laid along the pipeline. The events such as footstep, car moving and the digging generate the seismic waves. These sensors and modules acquire the seismic signals. The empirical mode decomposition is used to acquire the IMFs (intrinsic mode functions). Then the IMF kurtosis features are normalized and used to recognize the different targets. In order to improve the individual target recognition accuracy, it proposes to fuse the identification results by using the Dempster-Shafer evidence theory and obtain the final judgment. If the target belongs to threat, the location will be finished. The time-frequency analysis method is used to process the seismic signals. The EMD outcomes are transformed by Hilbert-Huang Transform and then it can acquire the signal's instantaneous properties such as instantaneous frequency, phase and amplitude. In this paper we also discuss the localization procedures and put forward to a new passive localization method based on HHT and TDOA. The filed trails show the proposed methods work well.

In order to understand the current situation of oil and gas pipeline detection technology, the author has collected relevant materials, both international and domestic. On the basis of these relevant materials, the existing detection methods were classified as the global damage detection technology and the local damage detection technology, both advantages and disadvantages were discussed. By summarizing and evaluating the situation of its development, the hot spots, the difficulties and the strategies of the research were proposed for the complexity, diversity and limitations of oil and gas pipeline health detection technology. The trend of its development has also been predicted. We truly hope that this paper could provide ideas for standardization and modularity of oil and gas pipeline health detection technology and offer some references to the researchers in this area.

Long range ultrasonic testing (LRUT) is an emerging non-destructive testing (NDT) ultrasound testing method. The LRUT technique uses low frequency ultrasonic guided waves to inspect plates and pipes efficiently for corrosion and other degradation. Increasing numbers of requirements for quick long range pipeline inspection have led to urgent need for improvement of testing methods and the development of new testing equipment to help the researchers in laboratory and help technicians in field inspection. The market for multi-channel ultrasonic instruments is characterized by small volumes of sales and a high ratio of development costs to sale price. The consequence is that the investment required to develop an instrument is significant and upgrades and other changes to instrument specification or configuration are difficult for many manufacturers to justify. These factors are particularly relevant for long range guided wave technology, where the technology is still relatively new in the market place and the instrumentation has different characteristics from other type of ultrasonic systems. In order to support the design and manufacture of the Teletest® FOCUS+ system, Plant Integrity Ltd has supported this study into the use of a fully programmable gate array (FPGA) based control circuits for the electronics, which allows the component count to be decreased and also permits the of the system to support future functions to be modified via flexible reconfiguration of the FPGA. This has benefits of reduction of size, weight and power consumption of the electronics and provides a means of upgrading the product without expensive re-design of hardware.

Ultrasonic guided wave (UGW) is very attractive for the quick inspection of pipeline structures because it can propagate a long distance along the pipe and through-out the whole thickness of the wall. In the conventional UGW-based techniques, piezoelectric transducers (PZTs) are often used as launchers and detectors simultaneously, which, however, makes the processing of actuator-sensor decoupling complicated. As an alternative, a new scheme using fiber Bragg grating (FBGs) to replace PZTs as sensors can be followed. This paper mainly concentrates on the preliminary work concerning the applicability of FBGs to UGW-based pipeline inspection. Based on the formulation of character equations and the analysis of dispersion curves, L(0,2) mode is selected as the testing mode. The response of FBGs to longitudinal ultrasonic waves is then investigated to put forward a hybrid PZT-FBG system for pipeline defect monitoring. A pipe, which is artificially introduced by circumferential and axial cracks with various severities, is numerically modeled based on finite element method (FEM). The results verify the feasibility and effectiveness of the proposed PZT-FBG scheme for pipeline inspection.

Underground pipeline is an integral part of the urban construction, as there are various pipelines in our city. These pipelines usually distribute in a special environment. Underground ferromagnetic metal pipeline which is magnetized by the earth's magnetic field can generate new magnetic field. The new magnetic field can change the original magnetic field distribution and lead to the formation of geomagnetic anomaly. Based on the magnetic dipole model and pipeline volume division, the underground pipeline ground remote detection model and close detection model are established. Through numerical simulation, the detection plane's magnetic flux density distribution curved surface can reveal intensity distribution characteristics of magnetic anomaly. The magnetic anomaly is caused by the single straight pipe. The geomagnetic abnormal data sampled by magnetic-resistance sensor can be used to judge whether underground pipeline exist or not, and indicate its orientation.

On the basis of analyzing the properties of underground pipeline used at home and abroad, using electromagnetic scanning theory, this paper proposes a new method, which combines other technical means, forming integrated detection method on urban road underground pipeline. At present it is used to solute the detection and analysis of slow speed problems on urban road, and to improve detection and analysis speed on the building of ensuring the accuracy of the same precision.

Every day, millions of people depend on the safe and reliable transportation of oil and gas through pipelines. Pipelines are historically a very safe means of transporting large quantities of oil, natural gas, fuels, and other hazardous materials. However, accidents of pipeline leakage have occurred frequently because of pipelines age, rot and third-party damage and destruction. Waste and pollution occur and result in such serious disasters as fire and explosions. A dependable leak detection system is important to promptly identify the occurrence of a leak in order to shut down the line, isolate the leak, initiate response actions, reduce the volume of the spill, and mitigate safety, environmental, and economic consequences of the release. Leak detection methods cover a wide spectrum of technologies and are based on a number of different detection principles. They vary from intermittent aerial inspections to hydrocarbon sensors to Supervisory Control and Data Acquisition (SCADA) based, real-time monitoring. Each approach has its strengths and weaknesses. This paper describes the capabilities and limitations of current leak detection systems. The operational principle, data and equipment requirements, strengths, weaknesses, and realistic performance limits for the leak detection methods are addressed in this paper.

Pipelines are the safest and most economic transport systems for natural gas. In the long-term life of the pipeline, there will inevitably be a rupture, leak or damage caused by manmade events or by natural disasters. Leaks may generate dangerous clouds of gas which escape from high-pressure pipes and produce serious fires and explosions, endangering the lives and property of people in and around the area. Monitoring natural gas pipeline leaks will, in time, discover and locate these dangerous situations and reduce loss. The core contents of leak monitoring are the accurate location of leaks as well as rapid identification of different signal sources, thus reducing the occurrence of false alarms. There are a variety of approaches currently used by pipeline operators to detect leaks in natural gas pipelines. This paper describes a developed leak detection approach based on Real Time Transient Model (RTTM) for leak detecting in natural gas pipelines which has been used in Central Asia/China Gas Pipeline. The advantage of this developed approach is that a leak which occurs in all flow conditions (including operational transients) can be detected. This RTTM model provides a sensitive alarm threshold and takes a very short time to detect leaks in gas pipelines. It can identify and locate small leaks in seconds.

Anti-corrosion coating and cathodic protection are usually combined to protect long-distance oil and gas buried pipelines. In this paper, it was proved that the cathodic protection current density could be a very good response to the working conditions of the pipeline coating and cathodic protection both in theory and practice, and the quality of pipeline coating could be classed by calculation and evaluation of cathodic protection current density. For an analysis of a pipeline with abnormal current density, important parameters such as the coating resistivity per unit area and the leakage current should also be calculated.

Most of long-distance pipeline communication is based on the fiber optical cable which lays with the pipeline in the same ditch. A special optical fiber cable can be added inside giving the cable a positioning function. Through a set of integrated automation system detectors for optical fiber cable line responses can occur on touch, vibration, cutting and other disturbance monitoring. Collection and analysis, which can help the master control room exercise proper judgment when disturbances occur while determining type and intensity, according to the prediction characteristics of disturbance signal. This fiber optical cable system protects pipelines from theft, invasion and destructive behavior by taking timely response measures for pipeline safety protection

Horizontal Directional Drilling (HDD) as the first candidate for petroleum and natural gas pipeline in East-west natural gas transmission project have been wildly used to install pipes and conduits for more than 30 years. However, large-diameter borehole increases the risk of drilling accident in weak cementation stratum such as sands, cobbles, and gravel. There are a few researches or studies on large-diameter (up to 1000mm) horizontal bore-hole while drilling slurry and reamer design. The objective of this paper is to analyze the effect of slurry permeability on the borehole instability and improving elastic-plastic model of horizontal bore-hole by citing permeability theory.

Utility and other companies are designing projects and define a certain window around the planned bore profile when considering HDD, a window in which the product is supposed to be positioned upon installation. During the presentation each stage of an HDD process will be theoretically evaluated regarding the accuracy on position capabilities and or limitations per stage. Navigation accuracy is off course an important factor, but also the selection of tooling can have its influence on where the product will finally be installed, other factors coming into play are the soil conditions, design of the bore profile and the product specifications. Pre and post installation logging techniques are used to verify the actual position of the product down hole and a small part of the presentation will be focused on that. HDD is an accepted and widely used installation technology; the target of the presentation is to get a better idea on the achievable installation accuracy.

This paper used commercial software to simulate the gas transmissions seismic transient response and stress distributions, assuming that the shield tunneling field experiences 8 degree seismic fortification intensity. The simulation offers an useful guideline for gas pipelines installation design. It also provides some key conceptual installing designs, such as enough gap between pipes and support, and water filling in all tunnel shaft.

Drilling bit is the most important tool. Its performance directly affects the quality, cost and efficiency of drilling operations. With the development of drilling technology and increasingly fierce competition, High quality, high efficiency and low-cost of the drilling technology is more and more attention. This also makes the drilling equipment getting more sophisticated. When the drilling, selecting the appropriate type of drill bit can raise penetration rate, increase the bit footage and reduce the drilling costs. PDC bit is a new drilling tool which develops along with PDC composite material. In order to increase drilling efficiency and reduce cost during drilling operations, it is necessary to do some research on PDC bit selection. In this paper, according to Analytical Hierarchy Process, the relationships among analyzing target level, principal level of influencing factor and alternative level is built, then the judgment matrices is constructed, and then the optimization model is established. Based on bit database, the model is applied in deep drilling practice in Daqing Oilfield, and bit optimization design in District Anda is taken as an example to analyze the model, finally the optimum PDC bit selecting program is presented.

There is an annular space with mud surrounding the installed pipeline after the completion of the project using Horizontal Directional Drilling (HDD). The mud in the annular space is super saturated soil with rich water, moisture away with time decreases the mud pressure, the unloading changes the soil stress around the hole wall, causing stress redistribution and the shrinkage of hole wall, and what's even worse, a certain space will form around the pipeline and hole collapse and surface subsidence. The shrinkage after construction is the key factor for the project quality in the directional drilling engineering, the formula of the shrinkage of hole wall after construction is the main problem to be solved. Analyzing the rules of the secondary stress and the radius of plastic zone in soil layer through analyzing the soil stress surrounding the hole wall with the SMP failure criterion and elastic-brittle-plastic model about sandy soil, summing the rules of the secondary stress field and displacement distribution and deducing the calculation formula of the optimal mud pressure, radius of plastic zone and displacement. In addition, getting the value of the displacement through numerical simulation with the FLAC2D . It can be found that the displacement law curve and the hole wall displacement is proportional to the final hole radius and the cover depth of soil through contrasting the results of numerical calculation and numerical simulation. At the same time, through changing the value of internal friction angle and mud pressure with other conditions remain unchanged, getting that the more internal friction angle and mud pressure, the smaller displacement of hole wall, the greater the stability of the surrounding soils. Providing the reliable theory basis for analyzing the hole wall shrinkage of directional drilling in sandy soil areas.

Generally speaking, there are three pipeline installation methods in mountain tunnel in seismic area: wall mounted, buried and bearing. There are no standards telling you which one is more appropriate. A general finite element software Ansys10.0 was used to simulate pipeline stress and strain under the earthquake load, and then adopting a modern numerical analysis method to analyze the results. At last, these three pipeline installation methods are compared in this paper in order to tell which one is the best, This should be a good reference to other projects.

This paper discusses cable pipe hierarchical laying and concrete hierarchical pouring, where layers of concrete are tamped and leveled using the plate vibrator. An anti-floating bracket is used to prevent pipes from floating and to maintain the space between pipes when pouring concrete. This technology features simple construction, low construction cost, and a short construction cycle, effectively solving quality problems such as pipe blockage, rupture, and floating when pouring concrete. The technology has been recognized as the best method for cast-in-place power pipe construction by Shandong Province, and its methodology is now an essential requirement in the construction industry's regulatory codes.

Taking Yuelai Waterworks with the daily water supply capacity 600,000 tons in Chongqing as an example, this study focuses on the characteristics and difficulties of municipal water intake constructions in rock along the upper reaches of Yangtze River. The key techniques of blasting engineering with the large diameter (2×14000mm), large geological depth (50m) of water pipeline constructions are described. The result shows that the smooth blasting technology can be applied to control the blasting contour precisely, the best blasting effect can be achieved through optimizing the blasting parameters, and the field precise leveling monitoring and information feedback can be successfully applied to guarantee the project quality and safety. Meanwhile, this demonstration project provides valuable experience and technical guidance for the future large diameter, large geological depth of water pipeline construction in rock.

The article is essentially dealing with new a system of quality control applied in an increasing number on German relining job sites. The system was worked out since 2004/2005 by a round table group of recognized experts initiated and organized by eight southern German cities. This group agreed on the most proven and scientifically sound, most reliable and most evident testing methods based on existing DIN EN ISO standards. The results are compiled in the two brochures DWA 143-3 and DWA 144-3 (DWA: German association of water industry, wastewater and waste). "Additional Technical Terms of Contract" were introduced in order to make the new system and its rules legally binding for CIPP jobs. The new system covers a number of quality related measures on the job site including sample preparation and it defines a two-step lab investigation of the sample. If the sample passes step 1 the liners' material properties are accepted. If the sample does not pass it is investigated more in detail in step 2 to make clear what the problems are and how to overcome them. Additionally, the new system is providing a standard static liner design that makes individual static calculations for usual relining job sites (significantly damaged but stable sewer, no peculiarities) superfluous.

Today's changing and globalized world allows us to live a more comfortable life than previous generations. Science, technology, and information shape societies in this century and affect their way of life. The constant production and evolution of science, technology, and information promise an easier and more pleasant life, a promise that in numerous cases is true. However, not everything needed for a good life depends on current inventions. On the contrary, it depends on what has been and has existed for generations. This is the case of the most precious resource on planet earth, water.

Based on requirement of intensity and thickness for the tubular nonwoven composite material by the big pipeline rehabilitation, the preparation and properties of the tubular nonwoven composite material were researched. To add fabric to reinforce the tubular nonwoven composite material; two pieces or more of the reinforced nonwoven were designed, so the structure of the tubular nonwoven composite material with the seams in circle direction equidistant, the structure of the tubular nonwoven composite material with many seams is symmetry, during inversion, the collecting of the stress of the single seam can be avoided, so the crazing of the seam is prevented; when the reinforced nonwoven is coverd film, at its two sides the areas for sewing were obligated, the difficulty of the sewing is decreased, the efficiency of the sewing is increased, and the thickness of the seam is decreased, the film jointing of the seam become more easy, the airproof of the tubular nonwoven composite material can be guaranteed. The test result shows that mechanical property, width and airproof property can meet the design requirement, and the corrosion resistance can meet the requirement of the standard.

Traditional trenchless rehabilitation methods for buried pipelines in plain city are feasible. In mountain city, however, most of the sewage pipelines are setup in the area which is difficult for the large construction equipments to reach. A rapid trenchless strengthen and rehabilitation method for large diameter GRP pipe in mountain city without large construction equipment is proposed in this paper. In the proposed method, the steel casings with strengthen ribs can be made out of the pipe and be constructed through the inspection wells without trench. The location of the casing segment and the size of the strengthen ribs are determined by the numerical simulation of non-linear finite element method. The strength and stiffness of the GRP pipe before and after reinforcement are also compared by numerical analysis. The effectiveness of the present rapid trenchless strength method has been confirmed by the application in the rehabilitation project of the pipelines at West Outlets, New Northern Area in Chongqing.

Laterals, connecting between the mainline sewer and individual households, have long been considered as a great source of infiltration and inflow (I/I) to municipal wastewater networks. This paper discusses decision support system focusing on a case study database that provides guidelines for the selection of technically viable and cost-effective lateral rehabilitation methods. The objective of this study was to find (1) how a case study database can be utilized to combine a list of parameters regarding lateral rehabilitation, (2) what is the average cost per linear foot per inch diameter ($/lf-in) for lateral rehabilitation, and (3) what are the most popular rehabilitation methods as well as host pipe materials. In order to accomplish these objectives, a questionnaire-based survey was conducted with municipalities and consulting companies across the USA, Canada, and Europe. Based on the data collected from survey and literature study, a list of 34 lateral rehabilitation case studies was summarized in a project database. The typical range of maximum and minimum values were presented for parameters such as lateral diameter, rehabilitated length, duration, and cost per linear foot per inch diameter ($/lf-in) of rehabilitation. It was computed that the average cost per linear foot-inch diameter for lateral rehabilitation methods using CIPP relining, pipe bursting, and flood grouting was about $20, $12, and $8 respectively. Furthermore, the most popular methods of sewer laterals renewal were CIPP relining and pipe bursting. Finally, it was observed that the most common lateral host pipe material was vitrified clay pipe (VCP).

The structure and types of the diamond string bead wire are introduced in this paper firstly. Then the grinding mechanism of the wire is studied based on cutting tests of the seabed oil pipelines. Micro morphology wear characteristics of the diamond string bead wire are analyzed. The surface morphology of the string beads after grinding proves that the analysis is correct. Lastly, the relationship curves between anti-wear rate and feed speed, curves between anti-wear rate and cutting speed are obtained based on the quantitative analysis of wear process and discipline in cutting seabed oil pipelines. And grinding surface quality by string bead wire is analyzed.

It is common that occur of the pipe break accident in urban drinking water distribution system. Pipe break accident in water supply network not only threatens the safe operation of the water supply system and the regulator of the water supply but also forms a direct hazard for the big population density, industrial development of modern cities. Repairing the pipe when it is break, can't meet the requirements of our modern life. Therefore, the prior update and repair of pipe is to be the key of solve the problem. By the pipe network hydraulic model that is established base on ARCMAP data, we can find that Capacity(fire flow). Criticality and Projected pipe breaks are three main factors that affect the pipeline repair through the research. According to the differences of the impact of each factor obtains an overall score through the comprehensive consideration. Comparing the size of the scores to determine the order of the priorities update and repair of the pipeline, and thus set out a reasonable repair plan.

Telecommunication pipeline resource is one of important infrastructures of the modern city, carrying many kinds of message transmissions. Daily maintenance and management are very complex; there are some resources management system based on GIS helper application pipeline resource management. But these systems generally use two-dimensional graphics to display pipeline resource current situation, to carry out statistics analysis and output of statistical reports and other functions, in the maintenance process of assigning maintenance tasks management and maintenance personnel are lack of effective interaction, which has disadvantages such as low efficiency. This paper introduces the telecommunication enterprise GIS system of pipeline resources repair, , through intelligent terminals, including mobile phones, the implementation of real time video pipeline resources maintenance, maintenance and management center and construction personnel interaction, reduce the workload and meanwhile greatly improve work efficiency.

To keep a good balance between precision and practicality and efficiently handle the pervasive vagueness information in pipeline transportation, a comprehensive framework entitled Pipeline Fuzzy Hazardous Index Method (PFHIM) is developed by combining the extensively used Pipeline Hazardous Index Method (PHIM) with the fuzzy logic theory. A modular and hierarchical structure of failure likelihood assessment about the third-party damage is established to denote the PFHIM in detail and specify the fuzzy inference process. A case study with regard to a hypothetical pipeline is given so as to compare the performance of PFHIM with PHIM. The results indicates that with the basically consistent assessment conclusions, the PFHIM does better in more realistically and predictive modeling, more detailed indicators classification and evaluation and less troublesome in re-weighting.

Zhongxian-Wuhan Gas Pipeline (ZWGP), put into operation at the end of 2004, is a part of the West-East Gas Pipeline Project of China. From Zhongxian to Yichang, about 400 kilometres in distance, the pipline goes through the mountainous area where geological conditions are complicated. Zhongxian-Wuhan pipeline is one of the the most outstanding piplines sufferring from geohazards in China. Geohazards investigation, risk evaluation and control engineering have been carried out since the pipline in service. This paper is to sum up the geohazard features and experiences of geohazards prevention and treatment. Based on 3 rounds of geohazards investigation along the pipeline, more than 183 geohazards sites were identified, including 96 landslides, 77 unstable rocks and 10 debris flow gullies. This article summaries the scale and distribution of geohazards along the pipeline, as well as the harm features of the pipeline. It is also introduced in this paper the geohazard management adopted by ZWGP, including the principles of geohazard prevention, running program, and frequently-used prevention methods.

The gas pipeline is a kind of linear project, which inevitably crosses complex geological conditions such as fault. Therefore, pipeline safety evaluation under the action of fault is very important for pipeline construction. This paper focuses on Hancheng CBM (Coal Bed Methane) pipeline project. Numerical simulation is conducted for the safety analysis of a crossing fault buried pipeline based on ANSYS finite element analysis software. The finite element analysis model for soil-pipeline interaction is generated by retrieving the engineering geological survey data. Some influencing factors are considered during calculation. Those factors include material nonlinearity of pipe and soil media, pipeline geometry parameters, fault type, broken bandwidth, fault occurrence and depth. According to calculation results, the influence of fault activity on the pipeline safety is analyzed and the corresponding countermeasures of disaster prevention and mitigation are put forward.

There are many factors and conditions, such as large uneven hypsography along the pipeline, obstacles, severe construction conditions and other external factors that can adversely influence the successful construction of long gas transmission pipeline projects. This creates various safety risks for project construction. This paper analyzes the reasons that cause safety risks in gas pipeline construction from three aspects; unsafe conditions of construction equipment, materials or environment, unsafe human behaviors, and management defects. In succession, the corresponding risk control measures are presented with representative examples.

Parallel laying of pipelines is of advantage to hydraulic protection, disaster prevention and space saving. However, it may increase interaction failure risk (one pipeline's failure influences the other). This paper analyzes the failure probability of two paralleled oil and gas pipelines to be constructed in China and estimates the consequential interaction failure risk of parallel laying. Reasonable suggestions are given by comparing calculating risk with acceptance risk criteria.

Reliability analysis is becoming a key issue in the engineering approach to the operational management of gas networks. However, measuring the hydraulic reliability of a gas network system is not a simple task as it can be related to a variety of parameters and properties of the network. This paper presents a systematic approach to the quantitive assessment and analysis of the hydraulic reliability of gas networks. The measures are calculated from the results of steady-state. It is only necessary to know the complete set of gas flows and pressures at nodes for each modeled situation. Firstly, the node pressure is selected as the state variable. Then, the standardized reliability evaluation curve is drawn in consideration of a variety of concepts and criteria, which shows the relationship between the state variable and the reliability index. In addition, the generalizing function is proposed to calculate an averaged-based value to represent the network. The nodes' demands are used as weights in the generalizing function to weigh each node value in terms of how much demand it affects. Moreover, a distribution of reliability measure values across demand nodes domain is obtained by the meanings of the percentile method. Finally, in a case study, this method is applied in the reliability analysis of a gas network system. The results show that the proposed method can quantify the reliability of gas networks and it may be used in direct support of gas network engineering and operation.

As a common geological pipeline hazard, the river washout has great influence on long-distance gas & oil pipelines. Action mechanisms and threaten types of river washout are expounded upon in detail based on years of geological hazard investigation and washout protection in Zhongxian-Wuhan Gas Pipeline and Lanzhou-Zhengzhou-Changsha Oil Pipeline. Scouring and erosion as well as change in the river's course are the main dynamic factors in river washout hazard. Floating, suspending, shoving and impacting are the four main types of threats in river washout. Some pertinent protective measures are presented on the principle of hazard mitigation. Concise structure charts and application conditions of those protective measures are also given. The latest results of performance evaluation for protection engineering shows that those protective measures have remarkable effect.

Based on cumulative damage theory, this paper examines wave-induced fatigue damage of submarine pipeline span under the wave. Constraint-equivalent method is used to deal with the boundary conditions of pipeline span according to the factual seabed supports for the pipeline. The nonlinear vibration equation, which satisfies the given boundary conditions, is set up and its closed form solution is developed. The fatigue damage models are detailed in frequency domain approach. A numerical example is presented to illustrate the technical models, and the effects of relative parameters such as span length, seabed stiffness, and hydrodynamic coefficients to fatigue damage are studied.

This study investigated the engineering characteristics of recycled materials in a controlled low strength material (CLSM). Controlled low-strength material (CLSM) is a self-compacting, flowable, low strength, cementitious material used primarily as backfill and void fill. CLSM is primarily used as a replacement of compacted soil in cases where the application of the later is difficult or impossible. Strength requirements are low in comparison to typical structural concrete. This enables the use of low cost, abundant, industrial by-products for the production of CLSM. The flowability and compressive strength of CLSM mixtures created using industrial by-products is the focus of this paper. The flowability of CLSM must allow efficient placement without segregation, while the compressive strength must provide structural support but allow for easy excavation. Consequently, there are minimum and maximum performance criteria for both consistency and strength. This research investigated the effects of using recycled materials in CLSM on the fresh and hardened CLSM properties. A total of six materials were used to create 18 mixtures that were batched and tested. The cementitious materials investigated were Class C fly ash and spray dryer ash; and the aggregates tested were bottom ash, crushed glass, recycled concrete fines, and crumb rubber. The results showed that CLSM with acceptable strength and flowability properties is attainable using these recycled materials.

Through the field cold bending and mechanical properties tests of Φ1219 mm × 22 mm X80 longitudinal submerged-arc welding line pipe, the effects of different bend radii consisting of 20D, 28D and 47D (D is the diameter of steel pipe) on properties of X80 linepipe were studied. The tests results indicate that the change of the transverse tensile property, roughness, hardness and bend performance of cold bends manufactured by various radius of curvature compare with the mother pipe is relatively small. When the radius of curvature is decreased, the transverse yield strength and yield ratio in intrados of bend increase slightly, but those in extrados of bend decrease in a little range. The changes of longitudinal tensile properties are bigger. When the radius of curvature is decreased,, the yield strength and yield ratio in intrados of bend decrease obviously, but those in extrados of bend increase. The longitudinal tensile curves in different position of bend exhibit a rather large difference. After the strain-age for mother pipe and bends, the effects of material deformation in the pipe production process appear which result in that the transverse tensile strength and yield ratio increase obviously. The longitudinal tensile strength and yield ratio in different position of bend also present a increase tendency.

Various kinds of drilling string vibration behaviors exist while deviated well (crooked hole) is drilling; the serious drilling string axial vibration will cause bit jumping, which is one of the most factors influencing deviated well drilling. Serious bit jumping phenomenon indicates that drilling string axial vibration shouldn't be neglected. This research studies on the whole drilling string in the crooked hole as subjects, and analyzes the laws that the whole drilling string axial dynamic behavior followed under the condition periodic exciting force exists. Through the whole and the part drilling string finite element analysis, mass matrix, stiffness matrix and dynamic matrix equation are acquired. Using computer program, distribution laws of drilling string axial vibration frequency are acquired, which indicates bit jumping occurs when forced vibration frequency and natural frequency are closed to each other. This paper provides a theoretical basis of researching drilling string dynamic behavior in the crooked hole, and the obtained observation would be a further guidance for analyzing drilling string vibration on extended reach well drilling.

The rescue channel is the necessary space to implement an effective rescue at a channel construction site; efficient rescue channel cutting is the most important matter of rescue operations. In addition to the digging of the rescue channel, this paper will analyze the difficulties and problems of the excavation of rescue channels, and expatiate the digging methods, devices, characteristic of traditional rescue channels. Based on research, the functions, the composition, and the structure layout of the rescue channel digging-robot will be proposed; as well as analyzing and designing various systems principles, functions, control strategies and control programs.

With construction of long-distance pipeline in China, the horizontal directional drilling of many pipeline is often through the rock, and the stability of the drilling is the key factor that pipeline successful pass through the rock. On the basis of previous experiences in engineering, the various factors of affecting stability were analyzed from rock mechanics point of view in this paper, including the in-situ rock stress and the hole fluid pressure and so on. Moreover, the formula of hole fluid pressure was deduced according to the compression-shear pressure and tension-fracture pressure, and an evaluation of the directional drilling through the rock mass stability criterion was established ultimately. This research can lay the foundation for theoretical studies of similar projects and it is guidance for practical engineering.

Strain-hardening capacity is the most effective way to improve the deformability of line pipe. In this paper, four kinds of new X70 high strain line pipe have been produced by four manufactures respectively. Microstructure, strain-hardening capacity, and characterization of the X70 high strain line pipe have been analyzed. It is concluded that X70 high strain line pipe steel does not fit to the Hollimon formula in the entire deforming process, and a stable strain-hardening exponent is not available. At the beginning of plastic deformation, the strain-hardening capacity of X70 high strain line pipe steel is excellent. It decreases rapidly as the stain increases then becomes stable after 2.0% total strain. The stress ratios of R_t1.5/_Rt0.5, R_t2.0/R_t1.0 and R_t5.0/R_{t1.0 are proved to characterize the strain-hardening capacity of X70 high strain line pipe steel. When Rt1.5}/R_t0.5≥1.070, R_t2.0/R_t1.0≥1.025, and R_t5.0/Rt1.0≥1.050, the average strain over the gauge length of 2 times the outer diameter, centered at the wrinkle on intrados peak, is above 1.3%.

Based on the major present urban water supply security problems, technology of water supply fault diagnosis is developed from the aspects of general loss of water network, bad water quality, water supply network emergencies and so on, mainly including the leakage detection of pipes, the research of localization technology, the monitoring technology of water quality as well as the emergency treatment technology of the pipeline. On the basis of these researches, a water supply security guarantee system frame is constructed, which can provide a certain technical support for the safety of water supply management.

During the process of traditional construction, quality problems often occur, such as loosening of manhole surroundings, cracks, sinking, losses of covers, vibration and abnormal sounds when driving, inaccurate control of the elevation of the manhole cover, inability to ensure the smoothness of the joining with the road surface, etc.. The technology of suspending style whole-reinforcement of the manhole cover can effectively resolve the above problems. This technology adopts fixed supports to suspend the manhole frame and adjust its elevation; set steel reinforced concrete perimeter beam beneath the frame to prevent the sinking of the cover; pre-buried steel bars are utilized to fix the cover, resist the horizontal push and prevent slides; pour the frame and steel reinforced concrete perimeter beam into an integral body to enhance the integrity of the structure. Make sure that no sinking occurs around the manhole and the cover is not easily lost and damaged and reduce the cost of replacing the cover. This technology bears great value of wide application.

Distributed effluent-treatment systems is selected as the effluent-treatment system for Plant M. Using water-pinch technology for wastewater minimization, a distributed effluent-treatment system segregates the different streams for separate treatments and only combines them if appropriate. For this multiple-contaminant and multiple-treatment process, minimum treatment flow rate of each contaminant is determined first (the true minimum treatment flow rate is the maximum flow rate among the minimum treatment flow rates for all contaminants); next, subnetwork is designed for the treatment of each contaminant; then, merge all the subnetworks and make all possible simplifications to obtain the final optimum treatment network. Distributed effluent-treatment systems present more advantages compared with centralized effluent-treatment systems. In a distributed effluent-treatment system, the streams are segregated and treated separately, reducing both capital and operating costs. The minimum treatment flow rate of Plant M is 114.25t/h, and the overall wastewater flow rate is 148t/h. The wastewater flow rate is reduced by 23%.

Prestressed concrete cylinder pipe (PCCP) tends to be of large diameter, making many failures of this pipe relatively catastrophic and costly. To date, most researches have been focused on PCCP inspection technologies and performance prediction in order to minimize the risk of accident. The performance of Prestressed Concrete Cylinder Pipe has been an interesting item of water utilities for a long time. Judged from the research progress at home and abroad, researches on numerical calculation of PCCP are lack of experimental verification. Furthermore, there are not any achievements in experimental research on super caliber PCCP (diameter >4m). In the paper, by the prestress relaxation, broken wires and the bearing performance tests of prototype large-caliber PCCP, the bearing characteristics and damage mechanism of PCCP were analyzed by the inner pressure and three-point external load tests. Aiming at the anti-crack external pressure experiment of PCCP, the effect of stored vertical cracks at the outer surface was discussed. The structure performance of PCCP was analyzed by applying the damaged plasticity model of concrete. The numerical calculation results were consistent with the experiment results. The numerical results show that the anti-crack external ultimate load had little effect by the core concrete crack. But the stress of concrete and mortar was concentrated around the crack and the damage of concrete appeared under the load. The whole work made up gaps for prototype PCCP test with the source of innovation and practical theoretical significance.

According to the Pipeline Risk Management Manual, weight relations between third-party damage index and its subordinate indices for most existing oil and gas pipeline assessment systems are invariable in any conditions. Bayesian network framework is established to analyze the uncertainty of relations between third-party damage index and its subordinate indices. Intelligent problem solving method is introduced to solve the above framework. The calculated weights with the Bayesian Network Proposed Frameworks are more practical value in China than the traditional weights in Pipeline Risk Management Manual. The risk assessment project for Karamay to Urumqi oil pipeline of Xinjiang Oilfield Oil Storage and Transportation Company is taken as an example. Compared with the traditional pipeline risk assessment system, the results calculated by the assessment system with the new third-party damage weights are more practical and provide reference for the pipeline operator.

Firstly, the paper analyzed the accidents occurred in recent years in Beijing, using security systems engineering. Secondly, by studying lots of literature, the risk assessment index-system of city gas transmission and distribution networks was determined from cause of the accident. The last, the weights to the risk factors were determined using AHP (The analytic hierarchy process), and the model of risk assessment based on CIM (Controlled Interval and Memory) model was built. This model has a guiding significance for scientific management of city gas transmission and distribution networks, and preventing the accident effectively.

The oil pipeline is the aorta of the countries economic development and the principal pillar of economic development. But with the aging pipeline, the accident of pipeline spills has increased year by year, resulting in the expanding scope of the contaminated environment. Since the first oil spill event occurred in 1969, tens of millions of oil leaks every year, causing serious harm on soil, biological and ecological environment. In this paper, aiming at the diffusion characteristics of the oil spill in the water or soil, the author introduces some concepts such as the cleaning efficiency, leakage volume equivalent on the basis of extensive research at home and abroad, which is combined with Chinas oil pipeline transportation. Then establish an appropriate risk calculation model in order to quickly calculate quantitatively the harmful consequences to the river, soil and ecological environment of the oil pipeline leaks, providing a scientific basis for decider to take a reasonable solution and effective way to bring the harm under control.

There are two parts of gas stations in one company which included purified stations and feed stations. Since 2009, the company station field started risk assessment of gas stations by RBI, and used a variety of methods of Consequences Grade. There are three methods included method 1(used SY/T6714-2008 Risk-Based Inspection base resource document),method 2(used API581-2008 Risk-Based Inspection Technology)and method 3(the gas stations own consequences grade). We carried out risk assessment of 20 gas stations(10 purified gas stations and 10 feed gas stations) and used these three consequences grades. Through the comparison of these three risk assessment results of 20 gas stations, we analyzed the respective serviceability, combined the effective content of the three consequences grades which included health consequence, safety consequence, environment consequence, business interruption losses consequence. The new consequences grade has built and carried out risk assessment of these 20 gas stations. Analyzed the results of the risk assessments, these results are more consistent with the actual situation.

Fault tree analysis method is used to carry on the safety and reliability analysis to the oil-gas pipelines in this paper. Firstly, establish the fault tree which top event is pipeline failure. Next, carry on the qualitative analysis to the fault tree. By the qualitative analysis, we can discover the major factors which induce the pipeline to failure and then establish the main risk fault tree. Finally, carry on the quantitative evaluation to the fault tree with main risk factors. Expert estimation and fuzzy mathematics analysis methods are used in the quantitative evaluation. In this way, the weak points of the pipeline system are distinguished, and we can also point out the basic event which improves easily if the pipeline system breaks down.

Municipal underground gas pipeline (MUGP) takes a high risk, because it would cause serious social and environmental impacts when it once failed. In order to ensure the safety and robustness of MUGP, a fuzzy integrate assessment and AHP are used together to analyze their randomness and fuzziness. This paper firstly reviews the research about MUGP. Based on the assessment theory of risk, the factors, which influence the fault frequency and consequence, are analyzed. Furthermore, the compartmental rule of fault frequency and fault consequence is given. Through comparative research, we get the conclusion that the main factors resulting in MUGP failing are corrosion, manufacture and installation bug, social environment and nature hazard. The common practice that using R = P⋅C to evaluate the risk may lead to unfavorable results. So, the assessment is divided into three stages: the first stage is to assess the risk probability (RP), the second one is evaluating the risk of consequences (RC), and the last one is giving the risk scores according to the risk matrix (RM). At the end of this research, the author gives a case study, which testifies that the proposed method is so valid and feasible.

The power cable infrastructure is a high risk system in a city, and various risk factors are in the mutual influence, which are distributed throughout the whole process of project management. Based on the composition and construction features of power cable project, this paper proposed the process of security risk identification, and the safety risk evaluation index of power cable system has established, and the quantitative risk assessment and classification. By identifying the main risk of power cable system, this paper proposed strengthening the monitoring and management of risk, and the effective risk countermeasures to avoid, transfer and control risk.

It is very common for a marine pipeline to pass through a shipping mooring area near a harbor zone in Bohai Bay, China. The risk of accidents caused by anchoring ships is a potential hazard which can lead to external interference with the pipeline. A procedure to calculate the probability for such a risk is proposed. The adopted methodology is based on the recommendations suggested by the DNV Codes. The same procedure is also applied to estimate the damage probability concerned with sinking ships.

In consideration of a series of damages to water distribution systems caused by urban land subsidence, risk assessment modeling is essential for risk management in large cities. Firstly, based on the function catastrophe characteristic of the water supply network suffered by the land subsidence, the Catastrophe Theory was employed to analyze the Catastrophe mechanism, and a function catastrophe simulation model was established accordingly to get the vulnerability index of water distribution system. Secondly, according to risk theory, risk entropy model was used to analyze the risk of pipe network suffering the land subsidence with the disorder and uncertainty features. Finally, the water distribution system of Guangzhou city was taken to the risk assessment model to get the risk index utilizing the level of land subsidence identified by the dimensional analytical method. The results indicated the risk assessment model is practical to provide strategic decisions for the security upgrade of urban water distribution systems under the danger of land subsidence.

Falling injury is one of the most frequent accidents in construction industry. In order to avoid casualties, protect the safety and health of workers, and promote work safety during construction, it has important significance to engage in more scientific analysis about prevention measures from falling accidents. This paper analyzes the accident types more prone to occur during construction and the cause of falling accidents from the four aspects of workers, objects, environment, and management, and then analyzes statistically the time disciplinarian resulting in falling accidents. Paper puts forward prevention measures to avoid falling accidents, and provides a reference for the construction industry to realize work safety.

Underwater shield tunnels, which bear high water pressure in the process of construction and operation, have a significant fluid-solid coupling effect. The paper adopts the FDM to study this effect of the drainaged segment lining, and gets the water pressure distribution on it. The internal force of drainaged segment lining has also been analyzed with the Japanese usual calculation method. The results show some useful phenomenon: different draining schemes have unique influence on water pressure distribution law. And the safety factor of the general segment changes gently, while the factor of drainage segment lining changes significantly.

This paper a three-dimensional finite element model of KangJiagou Bridge-Miaoling tunnel in mined-out region is built up to calculate surface level and vertical displacement of different working conditions, analyze the characteristics of surface subsidence, divide key part and delineate safety pre-warning range of the surface. At the same time the tunnel deformation and stress characteristics are studied and the tunnel's supporting parts are also determined through analyzing the concentration areas of structure stress, which make tunnel's stability been very well controlled. The research results can provide the theory basis and the technical guidance for the construction of tunnel in mined-out region.

The growth in tunnel construction in urban environment makes increasingly complex geological and underground conditions for new tunnels design and construction, which means new tunnels have often to be located very closely to the existing ones. Thus, the prediction of the influence of new shield tunnel construction on the existing tunnel plays a key role in the optimal design and construction of closely parallel shield tunnel to avoid any damage of existing tunnel during and after new tunnel excavation. To investigate the influence of new shield tunnel excavation on the internal forces and deformations in the lining of existing tunnel, this paper presents a series of three-dimensional numerical simulations and parametric analyses performed for two commonly configuration models between two parallel tunnels: horizontal parallel tunnels and inclined parallel tunnels. Special attention was paid to the influence of separating distance and relative position between two parallel tunnels. The results of numerical analysis indicate that the separating distance and relative position between two parallel tunnels have considerable effects on changes in deformations and internal forces in the built tunnel lining. It was found that a new tunnel excavated below and inclined parallel to the existing tunnel would induce higher deformation and bending moment in the lining of the existing tunnel than new tunnel was positioned in horizontal parallel to the existing one. For the two horizontally parallel tunnels, the distance between two tunnels below which the deformation increases substantially is about 3.5 times of tunnel diameter. These insights provide the references for engineers and technicians to make a much more scientific and rational design and construction of close proximity parallel shield tunnel.

Utility tunnel (UT) is an underground tunnel structure that carries more than two types of public utility lines, like pipeline and cable. Before 1970s, Utility tunnel had been considered to be a low seismic risk, however, in recent decades, UT have been found to be often damaged under strong earthquake motion and large ground displacement, and the pipeline system contained in utility tunnel was also observed damaged in earthquake, such as broken, tensile and torsion in joints, and dropping from its bear or anchor ring. Based on shaking table test and numerical simulation, this paper presents seismic isolation equipment for reducing seismic response of pipeline, and several parameters including the device stiffness and its damping, geometric size and layout related to seismic isolation effect are discussed by use of finite element analysis. It is proved that this device can make a 50~60 percent cut down for seismic response of pipeline.

When the shield machine launching or arriving is under construction in the shield tunnel construction, firstly the built retaining structure (piles in a row, diaphragm wall, etc.) of the shield tunnel portal needs to be excavated manually by tradition method, and then the shield machine launch or arrival construction is carried out. Consequently, after the built retaining structure of shield tunnel portal is excavated, it has become a key issue to ensure the soil stability of the work shaft portal for a period of time before the rotary cutter head of shield machine penetrating into or drilling through the stratum. Based on the project case, the principle of high pressure spiral jet grouting, the grouting parameters and the construction technology about dual pipe high-pressure spiral jet grouting piles for reinforcing the soil of the end well portal are discussed in this paper. Furthermore, some suggestions are put forward on the questions that exist in the jet grouting piles for the shield launching or arrival construction.

Based on the flexible pressure pipe structure calculation theory, by using the FLAC3D finite difference software, this paper analyzed the stress state of the flexible pipe and the rule of the pipe-soil interaction. Through orthogonal test method, the different parameter settings are named, such as the buried depth, excavation depth, excavation distance, the paper quantitatively studied the significance level of various factors which have effects on the pipeline excavation deformation. All the research will offer a scientific basis for the design and research of the follow-up flexible pipe.

In sandy gravel stratum, individual characteristic is prominent and ground structure is loose. Point-to-point contact model is popular between ground particles. Such ground is easy to be disturbed and remarkable ground loss often appears during shield construction process. The discrete element method (DEM) is applied to investigate the ground movement and disturbance induced by tunnel construction using the software PFC2D (Particle Flow Code in 2 dimensions). Ground settlement distributions at various ground loss ratios were obtained for twin tunnels with 0.5D and 1D clear distance. Loosing, collapse and arch formation of the ground were all revealed at meantime. This work can offer references to control and prevent the disturbance caused by shield tunnel construction in sandy gravel stratum.

The loess has a higher strength in the dry condition and strength reduction in water condition, this special engineering geological property brings serious impact on the metro shield tunnel construction in loess strata. Xi'an metro line 2 is the China's first metro shield tunnel constructed in loess strata, it is very necessary to reduce the impact of its construction on the ancient architectural buildings. According with the project of Xi'an metro line 2 passes beneath the bell tower, this paper established the three-dimensional nonlinear finite element model to study the impact of shield tunnel construction on the bell tower reinforced. The results show that, because of the reinforcement effect with swivel-driven piles, the surface settlement caused by shield tunneling is mainly distributed outside the piles and the surface longitudinal settlement curve has an obvious inflection point at the piles. The maximum settlement and tilt of bell tower base caused by shield tunneling satisfies the control standard and the reinforcement effect is significant.

Gradually increasing tunnels across the Huangpu River and the rapid development of subway tunnel network in Shanghai will inevitably induce the new subway tunnel construction close or above cross-river tunnels. Therefore, it is meaningful and essential to study the influence of subway shield tunnel construction on the existing underlying cross-river tunnel. By considering the longitudinal rigidity discount of shield tunnels, stress history in situ ground, and construction procedure of subway shied tunnel, the writers conducted a numerical analysis by three dimensional finite element program to investigate the responses of existing underlying cross-river tunnel due to the construction of subway tunnel above. The change law of displacements and internal forces in the lining of cross-river tunnel with the advance of tunnel boring machine was given special concern. Results shows that the maximum values of vertical displacement and lateral displacement of cross-river tunnel occur at the cross section rightly below the axis of subway tunnel, and the lateral value is comparatively smaller than the heave value. Meanwhile, the moments in cross section decrease and the axial forces in cross section tend to be even after the completion of subway tunnel excavation. The longitudinal stresses and moment increase gradually with the advance of TBM, and the leak at the crown of cross-river tunnel should be paid more attention since the tensile stress at this point increases during the construction of subway tunnel. As for the influence scope, beyond the horizontal distance of about 2D (D represents the external diameter of cross-river tunnel) to the axis of cross-river tunnel, the effect of excavation of overlying subway tunnel on the cross-river tunnel can be ignored.

Construction of shield tunnel will inevitably change the stress field and displacement field of soil mass. Consequently, adjacent existing underground structures will be affected by construction of new projects. As a typical example, the responses of cross-river tunnel due to overlying subway tunnel construction are presented and the influence of the vertical distance between two tunnels is particularly focused on. Considering the difference of discount coefficients between transverse rigidity and longitudinal rigidity of shield tunnel, the change of stress field in soil mass, and so on, the writers conducted numerical analyses via 3D finite element program for four values of vertical distance (2 m, 5m, 8 m, and 11.4 m). Displacements, curvatures, and inner forces of cross-river tunnel were selected to investigate the responses of cross-river tunnel due to new subway tunnel excavation with different distances. The results show that the rebound pattern and amplitude of cross-river tunnel depend on the distance between the two tunnels. The increase of distance induces decreases of rebound amplitude and maximum lateral displacement. Compared with the rebound values, the lateral displacement values are comparatively smaller and even can be ignored in engineering. In addition, the cross-river tunnel is almost unaffected beyond the distance of 2.5D (D represents the external diameter of cross-river tunnel) to the symmetric plane. Furthermore, the internal forces in symmetric plane of cross-river tunnel are close to the initial values and the internal forces in longitudinal direction decrease with the increase of the distance between two tunnels. Finally, the minimum curvature radii can't achieve the critical value in the four cases and the maximum rebound values exceed the critical value in some cases according to the criteria of metro protection in Shanghai.

A utility tunnel is a public underground structure that holds wires, conduits, pipes of power, gas, water supply and communication utility system and provides also enough space for maintenance. Construction of the utility tunnel represents the future orientation of development for underground infrastructure system in both cities and small towns because of it's many advantages as improving the project reliability, lessening maintenance cost and improving the environment. At present, many studies have focused on the affects of earthquake loading on the forces and displacements of underground structures, while the seismic response analysis of underground structure in liquefiable soil, especially to shallow utility tunnel is still lacking. The FLAC3D software has been used to simulate the pore pressure changes and utility tunnel internal forces characteristics during earthquakes that lead to soil liquefaction. The effects of soil features such as friction angle and dilatancy angle to the liquefaction are studied. The results show the increasing friction angle and dilatancy angle can be effective lessen the liquefaction and reduce liquefaction-induced uplifting of the utility tunnel. Some useful conclusions are obtained to understand the characteristics of shallow utility tunnel in liquefied soil through the analysis, which can be for design reference.

Earth Pressure Balanced (EPB) tunneling boring machine (TBM) establishes its dynamic earth pressure balance through conditioning the excavated soil, and discharges the extracted soil in screw conveyor smoothly. In this topic we refers the fruits of the slump tests on conditioning the excavated soil with foam, and conducts experiments on the mechanism of EPB conditioning the excavated soil in microscopic point of perspective. Assisted by Industrial CT Observing System, microstructure images of the unconditioned and conditioned soil are obtained. The images are processed with computer program written to get the different parameters of micro-structure between the conditioned soil and unconditioned soil. The results indicate the changes on micro-structural feature affected by foam. The experiments supply references for conditioning the excavated soil with foam in excavation of urban tunnels with EPB.

A new construction method named pipe curtain using for traversing fault of deep mine roadway was presented in detail. During the pipe curtain method, the pipes connected by shackles were jacked into the surrounding rock, and then the grout injection system in the pipes would grout slurry into the pipe joints and the broken surrounding rocks, which would finally form a curtain around the roadway. In order to further indicate the using effect of this new method, taking the part of traversing fault for conveyor roadway of Guqiao coal mine in Huainan mine area as an example, the deformation characteristics of surrounding rocks were simulated by the finite difference method (FLAC) by both the pipe curtain construction methods and the traditional support methods. Furthermore, the comparison work between the two methods mentioned above was carried out at the same time. The results show that the deformation of surrounding rocks using pipe curtain construction methods is very low and more uniform. Therefore, it can be proposed that using the pipe curtain construction methods would solve the problems during crossing fault such as roof fall and floor heave more effectively.

When MTBM is used to construct a tunnel in cohesive soil area, the main force need to resist is adhesive force generated by soil or clay around the machine, which can be reduced by the lubrication. In this case, the most commonly used lubrication is bentonite mud, which is injected through ports in the jacking head and filled outside of the pipes. In rock area, the formation is hard enough to support the pipes, if both entrance and exit are sealed well enough to prevent the lubrication lose, and also make sure the mud be injected continuously and around the pipe all the time which makes the pipes "float", frictions between pipes and rocks will be nearly zero under this "perfect" status. So we can conclude that in rock area, the lubrication system is not only to reduce the resistance force coming from the soil, but also to lower the frictional force coming from rocks. In some sedimentary rock areas, clean water might be the best lubrication. This theory has been successfully used and proved in different crossings of MTBM site in China's second West-East Gas pipeline project.

On the basis of the features of structrual design for Xi'jiang river slurry shield tunnel, the technique of laying natural gas pipes in the tunnel is presented in this paper. Gas pipes can be fixed in working shaft and main tunnel with clips or other clamping apparatus, pipes outside tunnel can be fixed with flange in concrete pier on river bank. When designing the installation mode of gas pipes in shield tunnel, the very important issue is to analyze the strength of clamping apparatus subject to pipe deformation and displacement caused by gas pressures and temperature variation in addition to water buoyancy and anticorrision of gas pipes. The method of laying gas pipes in Xi'jiang river shield tunnel may provide effective guidance for the design and construction of gas and oil pipes in cross river shield tunnel under similar circumstances.

In accordance with the characteristics of structural design of cross-river shield tunnel, the analysis for anti-buoyant stability of gas pipeline in shield tunnel has been conducted, and the design scheme including its corresponding engineering measures to resist the buoyancy of gas pipeline in both shield working shaft and the main subaqueous tunnel are concurrently proposed in this paper so as to guide the installation of gas pipeline and provide reference for the anti-buoyancy design and analysis of gas pipeline in cross-river shield tunnel under similar circumstances.

This paper presents an open end pipeline pullback method, in which a PE pipe is connected to the special designed pullhead inside the product pipeline. While the pipeline is being pulled in, the drilling mud in the borehole will flow into the PE pipe continuously through the openings in the pullhead. It is an innovative method that does not only solved the problem of buoyancy control of product pipeline during pullback, but also makes same other typical advantages such as borehole pressure control, more secure for pipeline and smaller pulling force. The case study indicates that the method is feasible and cost effective.

The production and quality control technique of high density polyethylene (HDPE) pipe used in trench-less installation, especially quick test of HDPE materials and HDPE pipes by simple experimental method was introduced in this paper. So that the quality of HDPE pipe product can be effectively controlled, avoiding the property loss of the pipe due to trench-less installation, ensuring the 50 years service life of the pipe.

The power pipeline trajectory measuring instrument is designed according to the principle of inertial navigation with a single axis gyroscope, two single axis accelerometers and a group of odometer wheels. It is used to measure the azimuth angular velocity, pitch angle, roll angle, the instrument walking speed, distance, and storage sampled data. The PC software realized the functions of communication, data processing, trajectory drawing, coordinate transformation and saved the trajectory as a *.txt which can be opened by Auto-CAD directly. Finally, a test has been done by measuring a real pipeline. The testing results show that the improved design is effective and valuable.

Trenchless horizontal directional drilling is the most widely used method in trenchless pipe-laying in China, of which the main formation is Quaternary strata. How to ensure the stability of the hole wall is the key issue to the success of the project in the drilling process. In this paper, a drilling fluid of powerful inhibition based on polyvinyl alcohol (PVA) was researched for trenchless horizontal directional drilling. This type of drilling fluid has a film-forming property, which can form a membrane-like substance if left to stand in air, and have a good effect on the stability of the hole wall in Quaternary strata. The author's research shows that: the polyvinyl alcohol (PVA) based drilling fluid of powerful inhibition has a better rheology and a stronger compatibility with other drilling fluid material, after investigating and analyzing a series of experiments for this kind of drilling fluids. It can meet the cleaning requirements of long horizontal directional bore hole if used with PAC. Compatibility with SPNH (brown coal resin) can reduce the loss of filtration and get a greater effect on lubrication drag reduction. The film-forming property and wall-protecting effect is particularly obvious when PVA is applied at the amount of 1.5% ~ 3%, especially suitable for trenchless horizontal directional drilling.

Non-dig underground pipeline laying technology is used widely in municipal construction, railway transportation, communications, water conservancy and transportation of petroleum and natural gas fields. Hard rock Non-dig construction is a construction field with high technology and construction difficulty in recent years. This paper analyzed the current domestic and international hard rock directional methods and types by used and pointed out its advantages and disadvantages, and putted forward a swing driving mode combined with the eccentric bit and DTH to realize Non-dig directional drilling in hard rock. The directional drilling principle is that in directional drilling the eccentric bit lateral force as a fulcrum deflection drilling through the swing mechanism, in order to avoid the drill pipe in curved segment of the cycle characteristics of destruction. On the other hand normal drilling is to use the swing mechanism and the drill pipe coordination with turn slowly to reduce drill speed and the drill pipe damage. The orientation principle is analyzed to solve oriented technology problems and key technologies in hard rock the Non-dig drilling and provides a new method.

In order to reduce the frictional resistance of the percussion-compact DTH hammer which was used for trenchless pipeline laying and improve its drilling efficiency, a series of cylinders with the drag reduction structural were designed. Then the progress of the cylinder drilling was simulated by ANSYS/LS-DYNA finite element analysis software. Lastly, their respective drilling efficiencies were analyzed scientifically. The results show that: the cylinder with the drag reduction structural applied to percussion-compact DTH hammer is feasible and its drilling efficiency is much better than the conventional cylinder, Furthermore, the effect of the drag reduction was influenced by the angel of blade cone (Anc), the number of the thick segment (N), the diameter of thick segment (D), the slenderness ratio of the thick segment (Sr) and the location of the thick segment (Los); As to the Φ130mm cylinder, Anc =20 °, N=1, D=134mm, Sr=1. 5, and Los at the bottom of the cylinder is an ideal parameter combination.

The paper concentrates on the horizontal directional drilling attitude measuring system which consists of acceleration sensors and magnetoresistive sensors. It does detailed analyses about attitude angle measurement error caused by the sensor manufacturing and installation error, and make compensation from two aspects of hardware and software according to the error sources. In these situations, for example: weak signals in the Geomagnetic field measurements and Vulnerable to the interference of changes of the current source in the environment, we will add arithmetic average filtering program on the basis of the software, besides in the hardware design with filters and in the software design of arithmetic average filtering and median value filter and amplitude limit filtering MATLAB simulation and actual testing; we do further analysis about magnetic deviation caused by the influence of magnetic material, and correct the magnetic deviation by the method of ellipse fitting. It has been certificated in the experiments that these measures improve the measurement precision of the system.

Stuck pipes usually leads to low productivity, frequently occurs in horizontal direction drilling (HDD) projects crossing rivers especially in complexity geo-condition area due to the anisotropic distribution of horizontal geo-condition and misusage of drilling tools. The experience gained while drilling vertical and directional oil wells was used for estimation of stuck pipe with respect to the site condition in Lan-zheng-Yangzi river crossing project. Soil and rock mechanics take a critical role in order to analyze the deep reasons of stuck pipe, and then, solutions were suggested for this project. This paper will focus on the solution of stuck pipe combining wellbore washing with case and pulling method, which was proved feasible for stuck pipe in HDD project.

The development of screw drilling tools plays an important role in the directional drilling industry. With the increasing market share of directional drilling, especially for HDD projects where screw drilling tools are employed for HDD pilot drilling, lots of screw products emerge every year and it leads to complex tools selection. This paper focuses on performance analysis which compares screw drilling tools of uniform-thickness with normal ones in order to provide engineers with the technical reference needed for HDD drilling tools selection.

Analysis of stability of hole wall has been an important technical problem in HDD engineering, but it's difficult to know whether hole wall is instability or not in actual drilling engineering. This paper was analysis of the main factors (Mechanical parameters of rock and soil, slurry pressure) that influence stability of hole wall, and then Midas GTS (Geotechnical and Tunnel analysis System) three dimensional numerical simulation software was used to simulate instability process of the rock and soil mass around hole wall in HDD, it calculated which stress, strain and displacement, and obtained calculation results in the form of corresponding vector cloud pictures. It can determine whether the hole wall is instability or not by this calculation results. This is the first application of GTS three dimensional numerical simulation new technology in HDD engineering. Practice has proved that this new technology is accord with fact and useful for project construction, it is worth to be applied to HDD engineering.

To evaluate the capabilities of horizontal directional drilling (HDD), the loads and stresses must be determined first. The loads of directional drilling tools, such as weight of drill string, torque and thrust at the cutterhead exerted by the drilling rig, reaction force at the rig, axial friction, circular resistance torque from friction as well as fluid pressure are analyzed with the consideration of structural characteristics of drilling tools. Axial stress, bending and shear stresses from torsion, shear stress from buoyancy force, tangential stress and radial stress from shear force are analyzed. Then, the influence of bottom hole assembly, drill-bit pressure, pulling back force, size of the borehole and density of drilling fluid on stresses of drilling tool with specifying parameters of drill string are analyzed. From the loads and stresses analysis above, the failure reasons of trenchless directional drilling are extrapolated and suggestions for preventing HDD failures are provided.

Trajectory of trenchless directional drill strings included slant section, bending section and horizontal section. Trenchless directional drill strings were under axial compression force during drilling process, while under axial tension force during hole reaming process and pulling back process. Because the trajectory and strength of trenchless directional drill string were influenced by the force exerted on each section, mechanical models of directional drill string were established to analyze the deflection equations and reaction forces in slant section and horizontal section under axial tension force and axial compression force. The boundary conditions in each section were taken as fixed constraint at one end and active constraint at the other end. After the analysis, the expressions of reaction forces as well as the deflection equations were deduced. And also, the reaction forces in horizontal section were got with given parameters of trenchless directional drill string based on the expression of reaction forces.

Though application of pipe-roofing and artificial ground freezing are becoming increasingly common, there are few published papers or practical projects concerning combined application of Pipe-Roofing Method and Artificial Ground Freezing Method (AGF), which can be named as Freeze-Sealing Pipe Roof Method (FSPR). In this paper, Gongbei Tunnel project of Zhuhai Link Road, Hong Kong-Zhuhai- Macao Bridge, which is proposed to be constructed by FSPR, is taken as the study object. Taking the development of temperature field, the resisting ability of the frozen ground curtain to thermal disturbance resulted from excavation, and the control of frost heave as criteria, analysis of different freezing schemes by numerical simulation is carried out for active and maintaining freezing stages, so that some guidance could be given for the final selection of freezing scheme. The results show that FSPR is capable to form a sustainable and stable waterproof curtain, and has good construction maneuverability. With the arrangement of enhancing pipes and limiting pipes, the freezing scheme can effectively resist the impact of thermal disturbance of excavation and limit the development area of frozen soil curtain to control the frost heave amount. The recommended freezing scheme of FSPR is reasonably practicable.

When the length of crossing is limited, two times of directional drilling crossing will be adopted. To excavate pit for connection of pipes can be yet regarded as a good solution in case that there are two times of directional drilling crossing. This paper is going to talk about the crossing of Weihe River in the second West-to-East project and introduce the design of retaining and protecting for pit excavation with depth of 19m under coarse sand as well as its construction, which provide reference and knowledge to apply pit to directional drilling crossing project as connection.

During horizontal directional drilling, the instability of borehole wall may lead to serious accidents such as too large torque, failure pullback of pipeline, abandonment of bore, etc. Based on the theory of elasticity mechanics and some assumptions, the mechanical model taking into account of initial ground stress and mud pressure is established. Under the practical conditions, cross-section of borehole is noncircular that is mainly caused by the subsidence of reamer. The real cross-section can be equivalent to a series of circles through curve fitting. According to superposition principle and the conversion relationship from polar coordinate system to rectangular coordinate system, the stress formula of noncircular cross-section is given. And then the finite element method is used to calculate and analyze the stress of borehole in the specific engineering. The results show the distribution and variation tendency of stress which can provide some beneficial reference for borehole wall stability study of horizontal directional drilling.

When using horizontal directional drilling (HDD) technology in a pipeline crossing project, the required pullback force is an important factor in the selection of the pipe strength and drilling equipment, as well as the construction technique.. There are presently several methods used to calculate this force. However, because of the complexity of the field conditions, it is difficult to construct a mathematical model that exactly matches the actual operation. It is therefore recognized that the pullback force cannot be precisely calculated, but may only be estimated. The present study considers several methods used to calculate the pullback force and compares the values. Based on these results, a modified procedure is recommended, which is verified to provide reasonable estimates of the pullback force reflecting the load due to the product pipe as well as that due to the reamer and drill string.

Horizontal Directional Drilling (HDD) is the fastest growing trenchless technology for the installation of pipes, conduits, and cables in underground bore-path construction. This is can be referred to the suitability of the technique for different soil conditions (hard and loose soils), applicability in crossing natural barriers such as rivers, lakes, and valleys, and artificial barriers such as highways and airport runways. Also, the technique has the less construction and restoration cost of new water and wastewater pipes and for rehabilitation of failing pipes in urban areas where excavation is unrequired or impossible. The 12 HDD operational units in 1984 increased to 2,000 HDD operational units in 1995. Approximately, 17,800 HDD unites were manufactured and sold during the period between 1992 and 2001 in the North America. About 32,135 units has been manufactured and sold worldwide including the year 2011 (projected statistics for 2011), 80% (25,708 units) were manufactured in USA. In this paper, HDD survey was conducted to get the current market and industry position of HDD technology by analyzing 14 responses from HDD contractors and consultants in USA. Topics studied included observed HDD applications in different soil conditions, project parameters (diameters, lengths, depths of boreholes, product pipe and materials), and HDD rig size and applications.

Horizontal Directional Drilling (HDD) is a suitable construction method for crossing beneath obstacles, such as rivers and lakes, highways, or special areas such as airport runways. In particular, HDD is the most appropriate, cost effective method for constructing new water and wastewater pipelines where excavation is not practical or possible. HDD operations are capable of traversing various soil conditions and meeting a wide variety of project requirements (pipe size and material, placement distance and depth). Nonetheless, the specific soil conditions and project details are important factors in determining the productivity of the overall operation, and these conditions must therefore be carefully investigated during the HDD design phase. The present case study provides observed HDD productivity values (ft/hr) in different soil formations (shaly clay, sandy shale, and silty clay) based on operations at a single HDD site, serving as a pilot project. In particular, the variation in HDD productivity during the reaming stage is provided based on the soil and project conditions encountered (diameter), while other conditions (e.g., contractor and HDD machine) remain constant.

As a washing medium, the drilling fluid is used to clean the hole in the process of drilling. Weighting material such as barite, iron-ore fines used for the preparation of high-density water based drilling fluid because of its high density and well wettability. However, the rheological performance is distinctly of vary types, sizes weighting materials for high-density drilling fluid. For controlling and maintenance of the rheological properties of high-density drilling fluid system, adding barite and iron-ore powder with different particle size into water based drilling fluids increasing the material density to 2.30g/cm3, obtained the viscosity effect which is defined as the variation of apparent viscosity after the drilling fluid rolling 24hours at high temperature (180°C), then analysis of its mechanism of action. The results show that, it is easy to forming strong particles as the core of the rules of the tentacles spherical structure with 250-350 mesh iron-ore powder to weight the water based drilling fluid, which could keep the stable rheological properties and make the size of solid particles integrated with the drilling fluid system closely not only holding the minimum viscosity effect also maintaining the best sedimentation stability. Similarly, 200-250 mesh barite perform the appropriate viscosity of water based drilling fluid and maintain a good sedimentation stability, and the maximum value viscosity effect is adding the 325 mesh barite.

Drilling fluid plays an important role in horizontal directional drilling (HDD). It cuts soil, suspends and transports cutting out of the borehole, it forms filter cake to prevent slurry lose and maintain the borehole stability. During HDD process, reasonable drilling pressure should be controlled. Maintaining the minimum mud pressure is required for regular drilling fluid flow. Maintaining the maximum allowed mud pressure is also required for borehole stability and prevention of frac-out. This paper briefly introduces the drilling fluid calculation method, then presents results of an application case in the Yangtze River crossing, which the length of HDD is 3300 meters. Base on the calculation, several recommendations are presented for this crossing.

A range of strata are easily disturbed on construction of curve pipe-jacking shallow-buried. Combined with engineering practice, some issue had been discussed in detail, such as (1) the selection of boundary conditions and criteria of the strength of the material by using Finite Element Method(FEM); (2)analysis of pipe-soil interaction effect by using FEM and on-site testing, which received basically the same results. The results show that (1)the scope of disturbance and variation value of formation stress are affected by the curve pipe-jacking shallow-buried in a one-time jacking distance, jacking speed, grouting pressure and the less the overlying soil thickness is, the more obvious the surface disturbance is; (2) the law of stratum movement is upheaval before settlement. On the longitudinal the disturbance scope is within certain extent before and after shield crossing, and on the horizontal the disturbance on the inner side of pipe axis is more obvious than that of external side.

Control of the borehole path is very important in Horizontal Directional Drilling (HDD), a widely employed method for the trenchless installation of pipelines. The main factors influencing the path control are analyzed in this paper, including the angle and area of the drilling bit guide plate, the soil properties, elastic bending & anamorphic characteristics of the drill pipe, size of drilling tools with fore thick diameter and the advance rate of the drilling bit. The effect of soil properties on path control was analyzed by means of laboratory tests. The results indicated that greater borehole path deviations occurred while drilling in harder formations. Three-dimensional computer simulations were performed, including visualization of stratum, underground utilities, manholes and the horizontal borehole path. The results of the study allow improved design of the pilot borehole, consistent with soil properties, location of underground utilities and drilling equipment characteristics.

In recent years, as there is a large number of pipeline projects in China, microtunneling, as a kind of trenchless method, has been widely used. Although Microtunneling technology has certain advantages in dealing with complex geological and environmental conditions, there also appeared some failure cases due to certain reasons in the process of construction. This paper discusses some typical cases of Microtunneling in recent years in China, analyzes the reasons for the failure and summarizes the solution of the problems encountered in the construction, which can be used as engineering experiences in the future.

The deformation of the borehole and the chocking (wedging) effect of surrounding soil on the pipe perimeter during the pull back phase may have a substantial effect on pulling force predictions for horizontal directional drilling (HDD) projects. However, this effect is not considered in existing methods for estimating the required pulling force. This paper provides a model representing the interaction between the pipe and soil, for which the soil is assumed to behave as a Winkler foundation. The stiffness matrix of a plane rigid-frame element considering such interaction was derived by variational calculus and the principle of minimum total potential energy. Moreover, a nonlinear analysis of the interaction model was conducted using the finite element method. The pipe displacement and chocking effect were investigated considering the pipe-soil interaction, and associated parametric studies were performed to determine the relative importance of the various factors. Pipe displacement is shown to increase with load and over-cut ratio, but to decrease with increasing oblateness of the borehole and modulus of foundation (subgrade) support. The chocking effect is shown to increase with load and oblateness, and decrease with increasing over-cut ratio and coefficient of degree of subgrade support. In addition, both the pipe displacement and chocking effect for an elliptical borehole are greater than for the circular borehole, under the same conditions.

The paper presents a model for predicting pulling force during pulling back phase in horizontal directional drilling. The analytical method develops the method given by Polak et al. in three aspects: (1) the soil is described by Winkler model and it constitutes an elastic support for pipe during pulling back phase, (2) considering the nonlinear rheological properties of slurry, power law model is used in calculation of fluidic drag friction, and (3) the resistance exerted on drill string is considered and pulling force at carriage is calculated. Except for the weight and weight friction of pipe outside pilotbore and fluidic drag friction, components of pulling force are calculated considering the effect of pipe-soil interaction by two parameters, namely pipe displacement and coefficient of chock effect which represent the displacement of pipe-soil contacting point and the clamping effect of soil on pipe in cross section during pulling back phase, respectively. A numerical program is compiled according to the given method. Comparison of HDD field data and predictions of pulling force indicates that the proposed method is rational.

Lanzhou-Zhengzhou-Changsha Pipeline Project, which supplies the product oil to two areas covering Hubei and Hunan provinces from the area at least 3,000 km away, crosses Yangtze River in Wuhan, Hubei province with pipe diameter of 610mm and length of 2,090m for crossing. The elevation difference between the lowest point and entry point is up to 75m. For this project, the main formation in crossing section is conglomerate and glutenite. As the conglomerate is very hard, of which the compression strength can be up to 59.7MPa, while the glutenite is easily broken, of which the minimum compressive strength only is 0.13MPa. The frequently changes of hard and soft due to the staggered distribution of conglomerate and gluenite and also the 12 fracture zones there makes the geology extremely complicated and the risk during the construction very high. Thus, this project is one of the most difficult HDD crossing projects in the world. This paper is going to introduce the details of the troubles encountered during this HDD crossing project and the solutions from the design stage to construction, so as to provide experience and knowledge for the design and construction of such kind project.

In order to standardize the inspection and evaluation methods for Drains, by studying the non-excavation pipeline repair project in Tianjin and the surrounding areas, the quality assessment parameters, choose CCTV Inspection for the best, finally concludes the defect type, establish the condition assessment model, including structural and functional defects. Investigate the technical specification for CCTV inspection and evaluation, it can provide a reliable basis for maintenance and economic analysis. At the same time, introduce absorpted and innovated many advanced repairing technology.

Pull-back force data is very important in designing pipeline crossing project by horizontal directional drilling, which is also the basis of choosing drilling machine. Through evaluating the maximum pull-back force, the damage of pipeline can be avoided. There have various factors influencing the pull-back force, such as engineering geological factors and operating conditions. There has no suitable universal mechanics model so far. In this paper the research object is a long distance product pipeline horizontal directional drilling crossing under the bottom of the Yellow River. Based on the research achievements and mechanics theory, the pull-back force has been respectively calculated by four kinds of methods, which are standard formula calculation, unloading arc earth pressure calculation, net buoyancy calculation and winch calculation. Then, the maximum pull-back force is determined by analyzing the applicable conditions and results of these four calculation methods. Finally, a securer, more effective and economical construction and pull-back force calculation method has been obtained, which can also provide valuable references for such kind of projects.

Trenchless construction for gravity flow installations presents considerable challenges as well as opportunities for the planners and the constructors. The need to achieve accuracy of line and grade, prediction and control of jacking forces, and ensuring structural integrity of installed pipes are some of the key issues that determine efficient and effective outcomes for longer jacking drives. As drive length increases, so is the likelihood of encountering complex geological conditions, and increased difficulties with controlling the alignment of the pipe string. This paper discusses how these issues were addressed in the planning study for the Bulimba Creek Trunk Sewer in Brisbane, Australia. For the 4.2 km long DN1500 gravity trunk sewer, up to 500m long drives were planned to avoid deep intermediate shafts in elevated and difficult to access topography. The shear interaction between pipe walls and ground, influence on jacking forces of key ground properties; and deformations of the overcut annulus around pipe were studied. The results were used to calculate jacking loads, estimate realizable drive lengths and planning shaft locations. Superior project outcomes with respect to design approach, constructability and environmental impacts were achieved for a deeper alternative alignment than originally intended.

In shallow Horizontal Directional Drilling (HDD), potential ground surface movement is an important issue, which is dependent on the soil characteristics and drilling parameters. In this paper, the soil parameters considered include soil density, modulus of elasticity, friction angle, Poisson's ratio, cohesion, and soil porosity. In order to obtain the effect or degree of influence of these parameters, the method of Fast Lagrangian Analysis of Continua Three Dimensions was utilized in the simulation models, which included two parts. The radial model was applied to the soil layer and the cylinder model to the horizontal borehole. The inner diameter of the radial model is equal to the borehole diameter. A total of eleven points at the model surface were monitored to determine the degree of movement and the distribution. The soil displacement vector around the borehole was obtained and the Tech Plot software was used to obtain the isoclines of the Z displacement around the borehole. The simulation results indicated that the elastic modulus, soil density and Poisson ratio had a significantly greater effect degree on the ground surface movement than the other parameters.