scholarly journals Study of contact forces in the bearing part of the protective coating of underground pipelines in gravel and cobbles

2021 ◽  
Vol 266 ◽  
pp. 01024
Author(s):  
R.A. Matsiuk ◽  
V.V. Ulanov
Keyword(s):  
Protective Coating ◽  
Bulk Material ◽  
Contact Forces ◽  
Granular Soils ◽  
Underground Pipeline ◽  
Foundation Soil ◽  
Underground Pipelines ◽  
Conditions Of Stability ◽  
Contact Mechanical ◽  
Coarse Gravel

In the construction and operation of underground pipelines, the feasibility of engineering methods of protecting the insulation coating from external mechanical impacts should be based on the existing loads. When an underground pipeline is laid on coarse gravel and very coarse soil, the analysis of the support forces at the base of the pipeline is a pressing issue. In particular, the difficult conditions for the construction, reconstruction, repair and operation of underground pipelines include cases when the pipeline route passes through sections of rocky soils. Discrete rocky conditions include large grain content in the form of coarse gravel, cobbles, and boulders. The article analyzes the influence of the size of foundation soil components on the magnitude of force arising in the protective coating of the support part of an underground pipeline depending on the unevenness of the soil and its granulometric composition. One of the directions for studying the distribution of contact-mechanical interaction in granular soils is a discrete model. The distinction of the discrete medium model is that individual elements of its structure are viewed as mechanically interacting bodies. Structural elements are particles of bulk material that can be considered as spheres. The results of modeling the contact problem using the discrete (granular) model of the base of the pipeline are presented. It was found that with the same diameter size and depth of burial, the force varies depending on the pipe diameter chosen in the project (for a pipe of 1420 mm, the maximum difference was 23%). In the case of unevenness of the ground, the force in the supporting part can increase by 3-5 times. The conditions of stability and strength of underground pipelines are formulated taking into account the discreteness of the base particles.

Research of conditions of supporting underground pipeline and loads on protective coating

2019 ◽  
pp. 130-139
Author(s):  
R. A. Matsiuk
Keyword(s):  
Protective Coating ◽  
Granular Medium ◽  
Underground Pipeline ◽  
Maximum Difference ◽  
Underground Pipelines ◽  
Insulation Coating ◽  
Permafrost Soils ◽  
Engineering Protection ◽  
Insufficient Knowledge ◽  
Coarse Soil

During the construction and operation of underground pipelines, there is a need to develop projects for the engineering protection of insulation coatings from the mechanical effects of coarse soil. The task is most relevant with significant variability of the laying conditions along the length of the route. In particular, the difficult laying conditions include the passage of the route in the areas of distribution of rocky, gravelly and permafrost soils. The appropriateness of applying the methods of engineering protection of the insulation coating from mechanical stress should be justified both economically and in terms of technical and operational indicators. Therefore, the task of analyzing the conditions of support of the underground pipeline and the study of the created forces in the supporting part of the pipeline is very relevant and characterized by insufficient knowledge. The article analyzes the effect of bedding soil and backfill on the amount of force arising in the protective coating of the supporting part of the pipeline in the presence of unevenness of the base and its particle size distribution. The results of modeling the contact problem using models of a discrete (granular) medium at the base of the pipeline are presented. The wall thickness of the pipes affects the change in created force in the supporting part of the pipeline (for pipes are 1 420 mm the maximum difference is 22 %). In the presence of unevenness of the base, the force in the supporting part can increase by 3–5 times.

The Design and Establishment of 3D Urban Underground Pipeline Plan Aid System

2013 ◽  
Vol 475-476 ◽  
pp. 1546-1550
Author(s):  
Ying Chun Tao ◽  
Lian Zhao ◽  
Guo Jiang Zheng ◽  
Bo Gang Yang
Keyword(s):  
Decision Making ◽  
Normal Operation ◽  
Underground Pipeline ◽  
Planning Commission ◽  
Municipal Planning ◽  
Pipeline Network ◽  
Scene Graph ◽  
Underground Pipelines ◽  
The City ◽  
Modelling Process

Urban underground pipelines are the lifelines of the city. With the acceleration of city modernization, the traditional way to design and manage pipeline plans which relies on 2D diagrams has been difficult to secure the normal operation of the city. In this paper, a standard automatic 3D pipeline modelling process is proposed; a way to manage massive 3D scenes by scene graph is raised; three patterns of 3D integrated visualization are suggested; innovative stereo displays of pipeline analysis results are thought out. Eventually, a 3D urban underground pipeline plan aid system has been developed. At present, the system has been used in Xicheng Bureau of the Beijing Municipal Planning Commission, providing valuable decision-making information for urban underground pipeline network planning and management.

Method for laying underground pipelines taking into account the danger of landslide processes

2021 ◽  
pp. 16-20
Author(s):  
Хабиб Миргалиб оглы Насиров ◽  
Тофик Инаят оглы Сулейманов ◽  
Рамиз Ахмед оглы Эминов
Keyword(s):  
Calculation Method ◽  
Landslide Hazard ◽  
Low Risk ◽  
Segment Length ◽  
Underground Pipeline ◽  
Landslide Activity ◽  
Underground Pipelines ◽  
Landslide Processes ◽  
Pipeline Design

Известная расчетная методика оценки риска воздействия оползневых процессов на подземный трубопровод позволяет вычислить количество возможных утечек и поломок, исходно приняв данный риск равным для всех равноразмерных отрезков трубопровода. Однако на практике равная степень подверженности оползневой опасности участков трубопровода является исключением. Таким образом, возникает необходимость разработки новой методики расчета, предусматривающей реальные условия проектирования и эксплуатации трубопровода. Авторами определено условие, при котором подверженность трубопровода утечкам и разрывам в результате воздействия оползневых процессов может достигать максимальных значений. Сделан вывод о том, что для обеспечения разумной низкой величины риска следует избегать выполнения полученной зависимости. При этом должны быть соблюдены следующие условия: трасса разделена на неравные отрезки, с увеличением длины отрезка пиковая скорость грунта убывает (то есть более протяженные участки трубопровода следует располагать вдали от зон возможной активности оползневых процессов). The well-known calculation method for assessing the risk of landslide impact on an underground pipeline makes it possible to calculate the number of possible leaks and breakdowns, initially assuming an equal risk for all equally sized pipeline sections. However, in practice, equal exposure to landslide hazard of pipeline sections is an exception. Thus, there is a need to develop a new calculation method that provides for real conditions for pipeline design and operation. The authors determined the condition under which pipeline susceptibility to leaks and ruptures as a result of landslide impact can reach maximum values. It is concluded that in order to ensure a reasonably low risk value, the implementation of the resulting dependence should be avoided. In this case, the following conditions must be met: the route is divided into unequal segments, with an increase in segment length, the peak soil velocity decreases (that is, longer pipeline sections should be located away from possible landslide activity zones).

scholarly journals A Study on a Matching Algorithm for Urban Underground Pipelines

2019 ◽  
Vol 8 (8) ◽  
pp. 352
Author(s):  
Shuai Wang ◽  
Qingsheng Guo ◽  
Xinglin Xu ◽  
Yuwu Xie
Keyword(s):  
Blood Vessels ◽  
Underground Pipeline ◽  
Matching Algorithm ◽  
Partial Matching ◽  
Spatial Objects ◽  
Operation Efficiency ◽  
Geometric Similarity ◽  
Underground Pipelines ◽  
Pipeline Networks ◽  
Matching Performance

Urban underground pipelines are known as “urban blood vessels”. To detect changes in integrated pipelines and professional pipelines, the matching of same-name spatial objects is critical. Existing algorithms used for vector network matching were analyzed to develop an improved matching algorithm that can adapt to underground pipeline networks. Our algorithm improves the holistic matching of pipeline strokes, and also a partial matching algorithm is provided. In this study, appropriate geometric measures were selected to calculate the geometric similarity between pipeline strokes in their holistic matching. Existing methods for evaluating similarities in spatial scene structures in partial underground pipeline networks were improved. A method of partial matching of strokes was additionally investigated, and it compensates for the deficiencies of holistic stroke matching. Experiments showed that the matching performance was good, and the operation efficiency was high.

Study on Influence of Tunnel Excavation on Seismic Performance of Underground Pipeline

2011 ◽  
Vol 90-93 ◽  
pp. 1801-1806
Author(s):  
Run Lin Yang ◽  
Tian Yuan Zhang
Keyword(s):  
Ground Motion ◽  
Seismic Performance ◽  
Seismic Action ◽  
Underground Pipeline ◽  
Buried Pipelines ◽  
Tunnel Excavation ◽  
Modeling And Analysis ◽  
Underground Pipelines ◽  
Earthquake Resistant ◽  
Before And After

It is often necessary to study on the seismic performance of the buried pipelines subjected to tunnel excavation, because the ground motion will inevitably endanger the nearby underground pipelines. In this paper, modeling and analysis of earthquake-resistant performance of tunnel excavation to the upper underground pipeline have been carried out. The changes of stress and displacement of the upper underground pipeline under action of the same seismic wave before and after tunnel excavation was compared. It is showed that there’s a greater impact on the stress and displacement of upper underground pipeline under seismic action, and a tunnel with reasonable supporting would support the underground pipeline to some extent.

scholarly journals STATIC STRAINING AND LONGITUDINAL OSCILLATIONS OF UNDERGROUND PIPELINE BUILT ON BLOCK FOUNDATION

2021 ◽  
pp. 123-133
Author(s):  
A. B. Struk ◽  
M. I. Vaskovskyi ◽  
I. P. Shatskyi ◽  
M. V. Makoviichuk
Keyword(s):  
Steady State ◽  
Stress State ◽  
Differential Equations ◽  
Analytical Solutions ◽  
Equivalent Stress ◽  
Forced Oscillations ◽  
Underground Pipeline ◽  
Underground Pipelines ◽  
Block Foundation ◽  
Static Tensile

The article considers the issues of forecasting the strength of underground pipelines, which are operated on seismically active sections of the route, composed of relatively rigid mobile blocks. According to the literature, the problems of the influence of the interaction of base faults on the stress state of the pipeline have not been studied to date. The aim of the work is to develop a model for the analysis of abnormal stresses in the underground pipeline on a damaged basis caused by static or time-harmonious mutual movement of its blocks along the axis of the pipe in the presence of several faults. Boundary value problems for differential equations of static tensile-compression and steady-state longitudinal oscillations of a tubular rod with discontinuous right-hand sides are formulated. Based on the analytical solutions of these problems for the cases of antisymmetric and symmetric displacement of the foundation blocks, the distributions of axial displacement and equivalent stress in the pipe, depending on the distance between faults and the frequency of forced oscillations, are investigated.

scholarly journals Inertia force effect on longitudinal vibrations of underground pipelines

2021 ◽  
Vol 264 ◽  
pp. 01007
Author(s):  
Barna Rahkmankulova ◽  
Sayibdjan Mirzaev ◽  
Sharafidin Aynakulov ◽  
Rakhmatjon Khusainov ◽  
Saparboy Khusainov
Keyword(s):  
Shear Stress ◽  
Numerical Methods ◽  
Seismic Wave ◽  
Relative Displacement ◽  
Inertia Force ◽  
Underground Pipeline ◽  
Longitudinal Vibrations ◽  
Inertia Term ◽  
Underground Pipelines ◽  
Elastic Shear

The effect of the inertia term on the longitudinal displacements of an underground pipeline is shown for various cases of pipe fastening when a seismic wave propagates along its axis. The problem is solved by analytical and numerical methods. The pipe-soil interaction is assumed to be elastic (shear stress generated in soil is proportional to the relative displacement between the pipe and soil).

Study on Risk Trend Assessment of Metro Tunnel Crossing Underground Pipeline Based on Partial Connection Number

2014 ◽  
Vol 580-583 ◽  
pp. 1283-1287
Author(s):  
Hong Tao Xie ◽  
Bo Li ◽  
Yun Sheng Zhao
Keyword(s):  
Risk Assessment ◽  
Underground Pipeline ◽  
Tunnel Engineering ◽  
Underground Engineering ◽  
Connection Number ◽  
Underground Pipelines ◽  
Trend Assessment ◽  
Metro Tunnel ◽  
Partial Connection

A model of risk trend assessment for metro tunnel crossing underground pipelines is proposed in this paper based on the partial connection number. This paper fully considered the certainty and uncertainty of the index and used "partial connection number method" to analyze the risk developing trend and its sort of metro tunnel crossing underground pipelines. A case study was performed on a metro tunnel engineering of Shenzhen Line 9. The results showed that this model considered the dynamic characteristics of risk, enriching the contents of risk assessment of underground engineering, which can provide a reference for the risk management.

scholarly journals An algorithm for computation of rainfall water drainage through underground pipeline and canal network affected by tide

1996 ◽  
Vol 18 (1) ◽  
pp. 15-21
Author(s):  
Nguyen Tat Dac
Keyword(s):  
Ho Chi Minh City ◽  
Real Problem ◽  
Underground Pipeline ◽  
Water Drainage ◽  
Practical Application ◽  
Canal System ◽  
Underground Pipelines ◽  
Unique System ◽  
Canal Network ◽  
Real Flow

It is given in this study an algorithm to calculate flow in underground pipelines connected to canal system affected by tide. The real flow regimes have been taken into computation. Pipelines and canals are considered as one unique system so their interaction has been included in the algorithm. Based on this algorithm a computer program named CONG1093 has been developed and applied to a real problem of rainfall water drainage in Tan Hoa - Lo Gom region, Ho Chi Minh city. The results of application shows practical application of the developed numerical model

Analysis of Effects of a Double-Tube Parallel Tunnel Excavation on Underground Pipelines

2013 ◽  
Vol 395-396 ◽  
pp. 477-480
Author(s):  
Dong Liang Guo ◽  
De Shen Zhao
Keyword(s):  
Material Properties ◽  
Its Region ◽  
Underground Pipeline ◽  
Analysis Model ◽  
Element Analysis ◽  
Tunnel Excavation ◽  
Finite Element Analysis Model ◽  
Underground Pipelines ◽  
Deformation Law ◽  
Parallel Tunnel

The interaction of a double-tube parallel tunnel excavation will greatly influence on underground pipeline of its region. This paper, taking Dalian Spring Street subway station as the background, uses the finite difference software to establish 3-D finite element analysis model to simulate the effects of tunnel excavation on underground pipeline, in which different embedment, material properties and diameters are considered. By analyzing of the settlement and deformation law of pipeline, the least affected pipeline conditions are drawn to provide corresponding guidance for subsequent underground projects.

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