The dynamic response of buried pipeline under impact load was simulated by the finite element method based on a coupling model of pipe - soil in accordance with the fact that bending failure occurs easily in large diameter buried pipeline under impact load. The ovaliza-tion deformation of pipe section and the strain distribution of pipeline were analyzed. Based on the strain criterion, the security of pipeline was checked. On this basis, some influential factors on the strain of pipeline were studied, such as buried depth of pipeline, ratio of diameter to thickness of pipeline, impact velocity and styleof soil materials. The results show that the increasing buried depth and ratio of diameter to thickness of pipeline, decreasing impact velocity, using softer soil to cover pipeline can decrease the strain of pipeline. The laws from the study in this paper provide some guidance significance for the disaster - resistance design of pipeline with large diameter and thin wall and the making of prevention measures.%针对大口径薄壁埋地管道在冲击载荷作用下易发生弯曲失效的问题,基于管土耦合分析模型,采用有限元数值仿真技术模拟了冲击载荷作用下埋地管道的动态响应,分析了大口径薄壁管的截面椭圆化变形与应变分布,以应变准则为依据校核管道安全性.在此基础上,探讨了管道埋深、径厚比、冲击载荷、管沟填充土等工程参数对管道应变的影响规律.研究表明,增大管道埋深,提高管道径厚比,减小落石冲击速度,回填土采用粘性较大的软质土等能够减小管道应变,研究所得规律对于大口径薄壁管道抗灾设计与防治措施制定有指导意义.
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