穿越逆冲断层的埋地管道非线性反应分析

穿越逆冲断层的埋地管道在地震作用下,容易发生局部屈曲或整体失稳等形式的破坏,研究逆冲断层作用下的埋地管道地震反应规律,对管道抗震设计及施工等具有重要的意义。本文将埋地管线及周围土体从半无限地球介质中取出,分别以空间薄壳单元和实体单元进行离散,采用非线性接触力学方法模拟管、土之间的滑移、分离及闭合现象;采用线性位移加载模拟断层的错动,考虑了系统初始应力状态的影响,对土体未开裂前的管土相互作用系统进行了拟静力数值分析;分析了位错量、土体刚度、埋设深度、径厚比及跨越角度对埋地管道反应的影响,得出了一些有益的结论。

Nonlinear Response Analysis of Buried Pipeline Crossing Thrust Fault

Buried pipelines crossing thrust fault are prone to cause local or overall buckling or other forms of damages during earthquake.So it's important for seismic design and constructions of buried pipelines to study the seismic response regulars of buried pipelines crossing thrust fault.The buried pipeline is separated from the semi-infinite earth medium together with the surrounding soil,and a three-dimensional finite element analysis model of pipeline-soil system is established using nonlinear contact treatment method.The pipeline is considered as the space thin-shell elements,while the surrounding soil is regarded as solid elements.The nonlinear contact elements are adopted to simulate the slip,the separation and the closure phenomena between the pipe and the soil.The fault movement is achieved by loading the linear displacements,and the initial stress condition of the system is considered at the same time.The pipeline-soil interaction system which presumes the surrounding soil does not crack is numerical analyzed with pseudo-static method.Some important influential factors,such as fault displacement,soil stiffness,buried depth,ratio of diameter to wall-thickness and crossing angle,are conducted.And some helpful conclusions are drawn.