Seismic Response Analysis Of Buried Pipeline In Slope Conditions

There are many major pipeline projects built or under construction in China.These pipelines stretch for hundreds of kilometers,even thousands of kilometers.Inevitably,they have to pass through some areas with extremely harsh and complicated engineering geological conditions,such as landslide,subsidence area,fault zone and so on.Landslide is one of the main geological hazards threatening the integrity of oil and gas pipelines.At the same time,China is located between the Pacific Rim Seismic Zone and Eurasian Seismic Zone.It has a wide seismic area,high intensity,high frequency and wide distribution of active faults.Once the pipeline is destroyed during the landslide instability caused by the earthquake,it will cause huge economic losses and even endanger people's lives.Therefore,it is necessary to study the seismic response of buried pipeline in the condition of slope topography.In this paper,based on ABAQUS finite element software,an appropriate buried pipeline model of slope is established for numerical analysis.The main contents of this paper are as follows:Firstly,this paper summarizes the research results and shortcomings of the slope site effect and the seismic response of buried pipelines,and expounds the research significance of this topic on this basis.In this paper,ABAQUS finite element software is used to carry out numerical simulation.The material constitutive model and the selection of boundary conditions are analyzed.The pipe-soil contact model and the method of ABAQUS model establishment used in this paper are given.Then,the numerical model of slope site condition is established by using ABAQUS finite element software,and the slope topographic effect in this site condition is analyzed.At the same time,the law of slope topographic amplification effect under different slope heights and angles is considered.Then,the deformation field at the bottom of the slope is calculated,and the optimal burial position is suggested according to the distribution law of the deformation field.At the same time,considering the variation law of deformation field at the bottom of slope under different slope heights and angles,the selection of pipeline embedding position under different slope conditions is given.After that,the numerical model of buried pipeline in the condition of slope site is established by using ABAQUS finite element software,and the failure mechanism of pipeline is obtained by analyzing the variation law of stress and displacement of pipeline.After that,the variation rule of pipeline response is analyzed when site condition parameters including slope height,slope angle and pipeline parameters including diameter and wall thickness change.Finally,the seismic response of pipeline in the condition of slope instability is analyzed by strength reduction method.At the same time,the variation law of internal force and deformation of pipeline under,inside and above the sliding body is studied.Finally,the best burial selection is obtained by analyzing the stress of pipeline at different buried positions.