地质灾害引发管道失效的应变分析

近年来很多基于应力设计的管道,在地质灾害等因素作用下,承受了超出设计条件的塑性变形,有的甚至引发了失效事故。对这些事故进行失效分析时,参考基于应力的准则,往往无法获得客观的结论。针对该问题,以某天然气管道环焊缝断裂的失效事故为例,以基于应变的准则,分析地层运动作用下的管道环焊缝的失效行为。结果表明,管道环焊缝在地层运动引发位移控制荷载的作用下发生了破坏。通过测量管道变形量,使用应变准则进行失效分析,可以定量获得管道失效环焊缝的临界应力及应变分析结果。

Strain-based Analysis for Pipeline Failure under Geologic Hazard

In recent years,many pipelines based on stress-based design have experienced unforeseen plastic strain due to geological disasters and other factors,and some have even result in failure.This requires that stress design standards often used cannot be used when performing failure analysis.Aiming at this problem,taking the failure accident of a natural gas pipeline girth weld fracture as an example,the pipeline failure behavior under the action of soil motion is analyzed.The results show that the pipeline girth welds are damaged due to soil-induced displacement control loads.By clarifying the amount of pipe deformation and using the strain/displacement criterion for failure analysis,the failure analysis results can be accurately obtained.