埋地管道的上浮屈曲分析

Upheaval Buckling of Buried Pipelines

使用材料力学方法研究了埋地管道产生上浮屈曲的条件。上浮屈曲常见于海底和液化土中的埋地管道,在上浮屈曲过程中产生过量的垂直位移和塑性变形被认为是一种失效情形。根据分析结果提出了管道温升问题。对于实际埋地管道,当运行时的温升大于安全温升时,管道即发生上浮屈曲。提出了管道上浮屈曲的两个重要因素:管—土之间的摩擦系数;管顶上覆盖土层载荷,包括管子自重和所含介质的重量。给出了实际算例。

Upheaval buckling often happens in sea bottom or liquefied soil when earthquake. Upheaval is regarded as a failure case due to the overdue vertical displacements and plastic deformation. The conditions under which upheaval buckling can produce are studied with the methods in mechanics of materials. According to the analysis,the safety temperature rise is presented. Upheaval buckling occurs when the operating temperature rise is larger than safety temperature rise. Two important factors which effect upheaval buckling are friction between pipe and soils,and loads of soil above pipe (containing the weight of pipe and liquid inside the pipe). Actual examples are given.