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讨论了地震断层作用下埋地管道有限元分析模型的几个具体问题。建议将穿越断层的埋地管道反应数值模拟问题分解为两个步骤,它们分别是基岩运动作用下覆盖土层的反应分析(步骤A)和断层引起的地面永久变形作用下埋地管道的反应分析(步骤B)。在后者的分析中,取出埋地管道与周围土体建立管土体系模型,并将管道和土体分别模拟为薄壁型空间结构和实体均匀介质,管道、土体及管土间的接触均采用有限元技术建模和分析。对于管土体系有限元模型中涉及到的一些问题,如力学分析模式、计算域的确定、断层运动的施加、管道与土体本构模型的选择、管土接触问题的处理、管土体系初始应力场的确定、管道破坏模式及判断准则等进行了简要分析和讨论。
Several specific problems of finite element analysis model of buried pipeline under earthquake fault are discussed. It is suggested that the problem of numerical simulation of buried pipelines crossing a fault be decomposed into two steps, that is, the reaction analysis of the overburden under the action of bedrock (step A) and the response of the buried pipe under the permanent ground deformation caused by the fault Analysis (step B). In the latter analysis, the pipe-soil system model was taken out from the buried pipelines and the surrounding soil, and the pipelines and soil were modeled as the thin-walled space structure and solid homogeneous medium respectively. The contact between pipelines, soil and pipe soil Are using finite element modeling and analysis. Some problems involved in the finite element model of soil-tube system, such as mechanical analysis mode, determination of computational domain, application of fault motion, selection of pipe and soil constitutive model, management of soil-soil contact problem, Stress field determination, pipeline failure mode and judgment criteria were briefly analyzed and discussed.