挖掘载荷下燃气PE管道损伤分析

Damage analysis of urban gas PE pipeline under excavation load

为分析第三方挖掘施工下燃气聚乙烯(PE)管道的损伤状况,借助ABAQUS有限元软件研究挖掘载荷作用下燃气PE管道的动力响应与力学特征。建立管道、土体与管-土接触模型,其中管道模型采用Prony级数进行模拟分析;确定PE管道强度、应变和变形失效准则;从挖掘载荷直接作用与未直接作用于管道2方面进行数值模拟。研究结果表明,挖掘载荷作用下,PE管道最易达到强度失效极限;载荷直接作用于管道时,管道的应力集中现象明显,而未直接作用于管道时,载荷主要影响管道的变形;载荷直接作用下,PE管道的安全运行受到严重威胁,而有覆土保护时,载荷对管道失效的影响较小。

In order to analyze the damage caused by third-party excavating construction to the PE pipeline,the dynamic response of the gas PE pipeline under excavation load was studied by using the ABAQUS finite element software. First,models were built respectively for the pipe,soil and pipe-soil contact,and the model for pipeline was simulated by Prony series. Then,strength,strain and deformation failure criteria of PE pipeline were established. Finally,the numerical simulation was carried out for two scenarios： the excavation load directly acting and not directly acting on the pipe. The simulation results show that PE pipeline is easiest to reach the strength failure limit under the excavation load,that the load acting directly on the pipeline causes remarkable stress concentration,and load which is not directly acting on the pipeline mainly affects the deformation of the pipeline,and that an external load directly acting on the pipeline is a major threat to its safe operation,and the covering soil layer can reduce the threat.