沉陷区域埋地管线数值模拟分析

Numerical analysis of buried pipelines subjected to the settlement

场地的不均匀沉陷是导致埋地管线破坏的重要原因之一。本文考虑了材料非线性、几何非线性以及管土接触非线性,将管线计算分析模型模拟为四节点薄壳单元结构,周围填覆土体采用八节点六面体单元划分。管土相互作用模拟为三维刚性与柔性的面面接触单元结构,并采用线性位移加载来模拟土体的沉陷作用,对三维薄壳有限元模型进行数值计算分析。通过比较不同参数,如沉陷长度、沉陷深度、埋深、管径、径厚比、土特性等对管线的反应影响,得出管线在沉陷情况下的应力和应变的关系,通过算例分析,说明了该方法能更好地模拟管线的破坏过程,该方法将为沉陷区域埋地管线数值模拟提供理论分析依据。

The uneven settlement is one of the important factors which leads to the damage to buried pipeline. In the paper, the response of buried pipelines is analyzed by means of numerical simulation, considering the material nonlinearity of pipelines and soil, the geometrical nonlinearity, and the interaction of pipelines and soil. The pipe is discretized into 4-node thin shell elements, 8-node solid elements are meshed in the soil entity, and the nonlinear contact element is created to consider the interaction between the pipeline and the surrounding soil. The ground settlement is achieved by loading the linear displacements. Many factors influencing the damage are analyzed with an example. The parametric studies on the distance of settlement have been conducted by employing the thin shell FEM method, such as the settlement depth, the burying depth of pipe, diameter, diameter-to-thickness ratio and the material of soil and so on. Finally, an example is provided for buried pipelines subjected to the settlement. Some conclusions are drawn, and the analysis method above will be a base research on the response analysis for buried pipelines subjected to the settlement.