跨断层水泥管试验的有限元分析

在考虑管道的材料非线性和几何非线性、管土相互作用的非线性和管道接口非线性的基础上,建立了由管体梁单元、三向土弹簧单元和接口单元组成的埋地非连续管道在断层位移作用下的有限元模型,并以美国密歇根大学Junhee等(2010)所做的跨断层水泥管试验为原型进行了模拟分析。有限元结果给出的水泥管最终变形、接口转角、接口位移与实验结果基本一致,表明本文提出的跨断层埋地非连续管道抗震计算的有限元分析方法具有一定的合理性。有限元结果和试验结果都表明,在逆冲断层作用下,水泥管的破坏主要是因为在管道接口处的轴向压力和弯矩的耦合作用,在断层附近的管道接口承受了较大的转动和压缩位移。本文所提出的分析方法可推广到埋地非连续管道在其它永久地面变形作用下的有限元分析。

Finite Element Analysis of a Buried Concrete Segmented Pipeline Crossing the Fault

To validate the experiment of buried concrete pipe crossing fault, which is designed by Junhee Kim at University of Michigan, we present a finite element simulation for this experiment in this paper. This finite element model, consisting of beam element, soil spring element in three directions and joint element, involves the material non-linearity and geometrical non-linearity of the pipe. It also considers the non-linearity of pipe-soil interaction and the non-linearity of joint when buried segmented pipe is subjected to the action of large displacement. The FEM simulation results, including the final shape of buried segmented pipe, joint rotations and joint contractions show good agreement with the experiment. Especially, large rotations and contractions of joints close to the fault plane are found in both the experiment and numerical simulation. The two kinds of tests also show that damage mode of pipe is due to a combination of failure mechanisms due to rotation and contraction. As a result, this simulation validates the new finite element model for buried concrete segmented pipelines. This model can also be extended in pipe subjected to permanent ground displacements.