Underground Pipeline Construction Research Articles

Temporal Trends in Soil Health and Productivity on Reclaimed Natural Gas Pipeline Rights‐of‐Way on Cropland

ABSTRACTThe construction of underground pipelines negatively impacts soil productivity in various ecosystems. However, the temporal progression in the recovery of soil productivity following the reclamation of cropland impacted by natural gas pipeline rights‐of‐way (ROWs) construction remains unclear. This study examined temporal, post‐reclamation changes in selected soil health indicators and productivity on reclaimed underground natural gas pipeline ROWs on cropland. Soil and crop samples were collected from ROWs ranging in time elapsed since reclamation (TSR) from 6 to 12 years and from adjacent undisturbed locations (off‐ROW) in the same field. The soil samples were analyzed for soil health indicators (permanganate‐oxidizable carbon (POXC), soil respiration, and autoclaved citrate‐extractable (ACE) protein) and selected chemical properties. Crop samples were assessed for grain and total biomass yields as well as grain protein content. Compared to the off‐ROW, soil organic C on the ROWs was 29% (6‐year ROW) and 33% (9‐year ROW) lower than on the off‐ROWs. Soil respiration recovered within 6 years of ROW reclamation, whereas it took 12 years for POXC and ACE protein to recover to off‐ROW levels. Grain and biomass yields 12 years post‐reclamation were still 42% and 36%, respectively, lower on the ROWs than on the off‐ROWs. However, measured soil attributes recovered faster than crop variables, indicating that pipeline construction on cropland has longer‐term impacts on crop yields than on soil attributes. These results indicate that, although underground pipeline construction has detrimental impacts on soil and crop attributes, these attributes would slowly recover to pre‐construction levels with increasing TSR.

Challenges in Underground Utility Tunnel Construction and Strategies for Intelligent Management

With the rapid advancement of urbanization, the importance of municipal infrastructure construction is increasingly highlighted. The municipal underground pipeline project, as a key link, aims to optimize the living environment and improve the quality of life services for the people. Given the continuous growth of urban population and the increasingly scarce land resources, the municipal comprehensive underground pipeline project effectively alleviates the pressure on urban land resources by efficiently utilizing underground space. However, the construction of such projects involves complex construction technologies, and scientific and reasonable intelligent management methods are needed to ensure project quality and construction efficiency. In view of this, the author discusses the challenges faced in municipal underground pipeline construction and the intelligent management strategies through participation in the design and construction of several pipeline projects.

试析市政工程施工中的地下管线施工技术

The construction technology of underground pipelines in municipal engineering is a crucial component of urban infrastructure development. Its advancement and application directly affect the normal operation of cities and the quality of life of residents. This paper defines and categorizes underground pipeline construction technology, outlines its development history and basic principles, and discusses in detail the preparatory work before construction, including surveying and measurement, design and planning, and the preparation of equipment and materials. In the section on specific applications, the paper deeply analyzes the characteristics and applicable scenarios of construction methods such as the open-cut method, trenchless technology, directional drilling, and pipe jacking.

Using digital technologies to plan and manage the pipelines network in city

AbstractPromoting the intelligent level of urban pipelines network planning and management is an important way to improve the rational development and utilisation of urban underground space and ensure the safe operation of urban infrastructure systems. The research on using the rapid and visual expression technology of 3D pipelines network model data, which has the functions of techno‐economic indexes calculation and automatic comparison of underground pipeline construction projects, effectively avoids possible errors in manual calculation and comparison and improves the efficiency and accuracy of the digital declaration process for project planning. In the 3D Geographic Information Systems (GIS) platform environment, this research help to develop many analysis and approval functions based on the data of the underground pipelines network model and the integrated pipes gallery Building Information Modelling, such as evaluating the compliance, feasibility and scientific of the planning scheme of the underground pipeline construction project, comparing the completion data with the data approved by the administrative departments of the project, evaluating the consistency of them and judging the compliance of the project completion data. The application results of some actual projects cases show that this research can improve the efficiency of planning declaration and approval analysis.

Bearing performance of high-strength bolted corrugated steel longitudinal seams

The assembly-type corrugated pipes have been widely used in underground pipeline construction owing to their rapid construction speed and strong adaptability to deformation. However, research with respect to the bearing performance and design methods of their longitudinal seams is lacking. In this study, axial compression tests were conducted on a single high-strength bolted seam of longitudinal seams of galvanised middle-wave corrugated steel plate structures to investigate the damage characteristics and bearing performance of the seams in different failure modes. A finite element analysis was also conducted to verify the test results and perform parametric analysis. The results showed that, to realise the maximum seam strength, the plate thickness should be matched to the bolt diameter. The torque coefficient hardly affects the ultimate bearing performance of the longitudinal seam, and the ultimate bearing capacity of the plate bearing failure seam is significantly influenced by the slip resistance coefficient. With the increase in waveform, the bearing capacity of seams increased by approximately 8.8% and 17.1% for the bearing failure of the plate, while it increased only slightly for bolt shear failure mode. Finally, several codes of bearing capacity calculation methods were compared with the test and simulation results. The revised Eurocode BS EN 1993-1-8:2005 accurately reflects the true bearing performance of corrugated steel plates with high-strength bolted connections. This study provides relevant reference data and design recommendations for seams that are easily overlooked in the design of assembly-type corrugated pipe projects.

Discussion on the Integrated Technology Development of Urban Underground Pipeline Surveying and Mapping

As a basic content of urban construction, underground pipeline surveying and mapping has made great progress in the development of urban information construction. The surveying and mapping technology integrating internal and external industries can promote the construction of underground pipeline system, which is an effective measure to coordinate the healthy development of the city. Because the underground pipeline construction is closely related to the quality of people’s quality of life, but also inseparable from the urban construction and development, therefore, it is necessary to improve the attention to the underground pipeline mapping. At present, although China has made great achievements in the research and application of underground pipeline survey and integrated surveying and mapping technology, there are still many deficiencies in the actual underground pipeline management, lagging behind the western developed countries. Based on this, this paper combines the relevant practical experience, summarizes the problems existing in the integration technology of underground pipeline surveying and mapping, undertakes the above theories, puts forward the corresponding thinking and suggestions, and makes a comprehensive discussion, in order to improve the integration level of underground pipeline surveying and mapping in China.

Application of GPR Underground Pipeline Detection Technology in Urban Complex Geological Environments

In the process of the continuous construction of underground pipelines, underground pipe network systems have become increasingly complex, which puts forward higher requirements for normal operation and maintenance. To address different kinds of complex conditions, this experiment in the present paper takes ground penetrating radar as the research basis and uses a self-correction and screening algorithm to innovatively detect underground pipelines. The results show that urban underground pipeline detection technology based on ground penetrating radar (GPR) can obtain a highly reliable number of pipelines and track predefined pipelines when detecting different numbers of verification pipelines. When detecting underground pipelines in different sections, the vertical and horizontal errors are no more than 0.199 m and 0.248 m, respectively, which means that the detection technology of urban underground pipelines based on GPR has high detection accuracy and can be performed on high-level detection tasks under various complex conditions. This research applies bottom detection radar to urban underground pipeline detection technology under complex conditions for the first time, innovatively uses the action mechanism of bottom detection radar, integrates its high precision and high efficiency into underground pipeline detection technology, and ensures the effectiveness of the detection work.

Research and application of calibrating device for pipeline detector

Underground pipeline is an important part of urban infrastructure, known as the “lifeline” of the city. At present, there are many incomplete data of urban ground line pipelines, only part of the data is not high precision or inconsistent with the status quo, which is easy to cause serious accidents in the construction of underground pipelines often cut or damaged, so it is particularly important to establish a reliable underground pipeline database as soon as possible. Pipeline detectors currently occupy tens of thousands of units in the market, and the annual growth rate of 20%∼30%. At present, the positioning error (sounding error) of pipeline detector is faced with the problem of undetermined and untraceable. The relevant calibration device established in this paper can provide reliable data and provide strong guarantee for the data of pipeline detector.

Analysis of Underground Pipeline Construction Technology in Municipal Construction

Analysis of Underground Pipeline Construction Technology in Municipal Construction

Modern design system for field underground pipeline construction in permafrost soils

This paper describes the experience of specialists from TomskNIPIneft in the underground pipeline laying in permafrost regions. The integrated and strength analyses are given herein, and the importance of considering the different factors for these analyses is shown as well as the limitations of conducting various scenarios of soil modeling. The important points are identified for carrying out the software-based strength analysis. Compensating measures are taken in the underground pipeline laying in the permafrost region. The technical solution is proposed for the use of frozen soil supports; its essence is described. The general block diagram of the heat engineering and strength analyses is presented in this paper.

PURPOSE AND DESCRIPTION OF THE COMPRESSOR STATION

All work on the construction of pumping and compressor stations is usually divided into two groups of zero cycle work and ground cycle work. The work of the zero cycle includes the preparation of the construction site, earthworks, work on the construction of foundations for buildings, pumping units and technological equipment, work on the construction of underground pipelines and utilities. The work of the ground cycle includes work on the construction of buildings for pumping and compressor shops and auxiliary buildings, installation work on installation and fixing on the foundations in the design position of pumping units. Compressor stations (CS) have been installed along the pipeline route to maintain a certain flow rate of the transported gas and to ensure optimal pressure in the pipeline. A modern compressor station is a complex engineering structure that provides the basic technological processes for the preparation and transportation of natural gas. Keywords: compressor stations, gas pipeline, building structure, Booster compressor stations.

The Stabilization Ensuring of the Underground Pipelines Design State in the Permafrost Conditions

The article considers one of the possible options for improving the technology of construction of underground pipelines in conditions of permafrost soils, which today is very relevant. The most significant disadvantages of the existing methods of underground laying of pipelines on permafrost soils are the thermal and mechanical impact of the pipeline on the soil base during operation and the occurrence of unacceptable plastic deformations of the pipeline. The purpose of the studies is to prevent or minimize the thermal impact of the pipeline on MMG during operation, and as a result, to ensure stabilization of the design position of the pipeline by preventing unacceptable plastic deformation of the pipeline. The main tasks solved in research: develop a method of laying an underground pipeline that eliminates thermal impact on the containing frozen soil; simulate the underground pipeline laying structure and calculate stress-strain state in the ANSYS software complex, as well as forecast calculation of thermal interaction of the structure on frozen soil in the FROST 3D Universal software complex.

Numerical Study of the Use of Tyre-Derived-Aggregate (TDA) as the Backfill Above Flexible PVC Pipeline

Tyre Derived Aggregates (TDA), produced by shredding scrap car tyres, show many interesting features, such as: durability, low bulk density, thermal insulation, good drainage properties or ability to damp vibrations, which makes them a useful material for civil engineering. One of the possible applications is the partial filling of excavations with TDA during the construction of underground pipelines in order to decrease the load applied on the pipe. The article presents results of a multivariate numerical study of 2D FEM models of a flexible PVC pipe - soil system, in which the presence of a mixture of sand and TDA (tyre chips - 40% by weight) (STCh) in the backfill was simulated. The models differed in the thickness of the STCh layer (t = 0 – 0.9 m) and inclination of the excavation walls (a trench with vertical walls or open excavations with 3:1 and 1:1 slopes). The main goal of the numerical analyses, performed by means of the Z_Soil.PC program, were to investigate the effect of the presence of the softer STCh layer in the backfill zone on the pipe deformation (relative deflection δ/D) and internal forces in the pipe wall. The soil was simulated with the use of either the Hardening Soil Small (HSS) or Coulomb-Mohr (CM) constitutive model with the parameters’ values estimated based on results of laboratory tests (published by researchers from Wollongong University). The PVC pipe was modelled as linear elastic. The results of the analyses show that, due to enhanced arching, STCh layer of the optimum thickness t = 0.55 m can effectively reduce δ/D when used in the backfill of the trench. It can also decrease the difference between the maximum and minimum bending moment in the pipe wall, leading to less ovalization of the pipe cross-section. This positive effect diminishes if the width of excavation is larger, as the model is gradually transforming towards the positive projecting conduit type. The CM model gives underestimated values of the pipe deformation and internal forces. Though, in the case of lack of all the HSS parameters’ values, it is better to use the CM model with E = E 50 than E = E ur as it gives a better approximation of pipe behaviour.

The application of pipe jacking technology in urban underground pipeline construction

The application of pipe jacking technology in urban underground pipeline construction

Influence of welding processes for underground pipeline repair on welder safety

The object of research is the welder safety during the repair and construction of underground pipelines. It is established that manual electric welding is characterized by significant influence on the human body, since the distance from the place of welding to the welder is 20–30 cm, the temperature in the pillar of the welding arc reaches 6500 K. It is contributes to the allocation in the surrounding space of a significant amount of metal vapor and fine particles (welding aerosol and toxic gases). Theoretical and experimental investigations of the initial part of the welding torch (at a height of 0.4–0.5 m) using manual, semi-automatic welding in the environment of protective gases and welding under a layer of flux have been carried out. Dependencies for determining axial temperatures and velocities are proposed. It is substantiated that the spreading of aerosols during welding of pipelines in the trench is determined by the physical processes of spreading the welding torch. The hygienic characteristics of the electrodes of the ANO type in the welding processes are investigated. It is established that the total amount of aerosol in the process of welding using ANO-4 electrodes with basic coating reaches 31 g/kg and toxic substances in aerosol up to 9 g/kg. The amount of gases in front of the welder shield during the welding of electrodes by ANO-8 reaches 20 mg/m 3 . Empirical equations for determination of aerosols concentration and gaseous concentration of harmful substances are obtained. In addition, an equation for determining the index of workplace pollution of welders, which made it possible to predict individual parameters of working conditions, is obtained. The mechanism of propagation of aerosols in the trench requires a special consideration, which can be carried out by the method of mathematical modeling, because such physical and chemical processes, as longitudinal and transverse dispersion, molecular diffusion play a role. The analysis of empirical formulas which can be recommended for determination of parameters in the initial section of a welding torch using flash welding of a pipeline in a trench is done.

BIM+ Robot Creates a New Era of Building Construction

BIM, namely the Building Information Model, though has made up for the shortage of CAD 2D drawings in the design and exhibition stage, there are still some vulnerable spots in building construction such as the inaccurate positioning of basic components. BIM robots effectively solve the practical construction problems of BIM. This paper briefly describes the application and shortcomings of BIM in the construction industry, and then introduces the BIM robot through practical cases such as bridge, decoration and underground pipeline construction, and summarizes its advantages and disadvantages, and points out other development directions of robots in the field of construction engineering.

Cost Based Value Stream Mapping as a Sustainable Construction Tool for Underground Pipeline Construction Projects

This paper deals with application of Value Stream Mapping (VSM) as a sustainable construction tool on a real construction project of installation of underground pipelines. VSM was adapted to reduce the high percentage of non-value-added activities and time wastes during each construction stage and the paper searched for an effective way to consider the cost for studied construction of underground pipeline. This paper is unique in its way that it adopts cost implementation of VSM to improve the productivity in underground pipeline projects. The data was observed and collected from site during construction, indicating the cycle time, value added and non-value added of each construction stage. The current state was built based on these details. This was an eye-opening exercise and a process management tool as a trigger for improvement. After the current state assessment, a future state is attempted by Value Stream Mapping tool balancing the resources using a Line of Balance (LOB) technique. Moreover, a sustainable cost estimation model was developed during current state and future state to calculate the cost of underground pipeline construction. The result shows a cost reduction of 20.8% between current and future states. This reflects the importance of the cost based Value Stream Mapping in construction as a sustainable measurement tool. This new tool could be utilized in construction industry to add the sustainability and effective cost management.

Developing the drilling tool for trenchless pipeline construction

The most promising methods of underground pipeline construction are discussed. To increase the efficiency of the drilling tool for underground pipeline construction the following research methods have been used in the article: optimization method of Evolutionary strategy, finite element modeling. The influence of geometric parameters of the drilling tool on force characteristics of enlarging the drill hole has been investigated.

Buried pipeline responses to ground displacements induced by adjacent static pipe bursting

To minimize disruptions of economic and social activities on the ground surface in urban areas, trenchless techniques such as pipe bursting are often considered for underground pipeline construction, rehabilitation, and renewal of existing utility services. Pipe bursting, however, inevitably induces outward displacements of surrounding soil, and subsequently leads to potential damages to adjacent structures and utilities. This paper carries out finite element (FE) analyses to investigate effects of the static pipe bursting–induced ground displacements on adjacent pipelines. In total 760 FE parametric studies are performed to encompass various combinations of ground settlement profiles, pipe dimensions, material properties, and soil properties that are typical of utility pipelines and pipe bursting in urban areas. The FE parametric results are summarized in a dimensionless plot of relative pipe–soil stiffness versus ratio of maximum pipe curvature to maximum ground curvature, which can be used to directly estimate the maximum pipe bending strain and (or) directly evaluate pipeline responses to adjacent pipe bursting. A worked example is provided to illustrate usage of the dimensionless plot. It is further found that the pipe–soil interaction is similar for pipe bursting and tunneling, and the effects of both pipe bursting and tunneling on adjacent pipelines can be assessed using a unified dimensionless plot. Effects of the intersection angle between the pipe bursting centerline and adjacent pipeline are explored. The pipe responses are shown to be underestimated or unconservative when only the perpendicular case is considered in the analysis.

Are old Mediterranean grasslands resilient to human disturbances?

Many dry herbaceous ecosystems suffer damage and are characterized by low resilience after disturbance. Among these forms of disturbance, soil excavation due to the construction of underground pipelines affects vegetation at plant community and landscape scales. Synchronic studies are the best approach for more rapid study of plant succession on ecosystems with low resilience. In order to better understand plant succession in a Mediterranean dry grassland, we compared the effect of a recent disturbance caused by the digging of a pipeline in 2006 with that of a pipeline created in 1972 in the same area. Surveys of floristic composition and richness were carried out along both pipelines in order to understand the succession after this single disturbance, one that does not drastically change soil chemical properties unlike former agricultural practices. Nevertheless, this type of disturbance still changes the floristic composition in the long term (>30 years). The first stage begins just after disturbance with the occurrence of many weed species. Another level between the first and the mature stage was characterized in our study, 30 years after the disturbance, by an assemblage of annual and perennial species but still lacking species typical of the reference steppe. The reference steppe is described as the mature level of the succession with an assemblage of typical grasses, forbs and a few small chamaephytes and, in particular, by the presence of Brachypodium retusum. This community corresponds to a very old Mediterranean grassland that has evolved under the Mediterranean climate and traditional sheep grazing management systems since the Neolithic Age. This study confirms the low resilience of this steppe community and shows the importance of pursuing research on this steppe and in particular on the biotic and abiotic processes involved in community assembly.