断层内含体积型缺陷的埋地管道错动反应分析

Analysis on Seismic Safety of Buried Pipeline Containing Volumetric Defects in Fault Movement

基于实体模型和土弹簧模型,分析了含体积型缺陷埋地管道在断层错动下的应力应变反应,探讨了断层内含缺陷管道和无缺陷管道在错动作用下应力应变分布的差异。研究了不同缺陷深度、面积和位置等因素对管道顶部和底部应力应变的影响;基于有限元计算的等效应力应变、ASME B 31 G圆周断裂应力和管道的容许应变,建立了含缺陷管道错动反应的安全评判准则,分析了含体积型缺陷的埋地管道在断层错动下的安全性。当缺陷深度大于30管道壁厚时,对管道在断层错动下的安全性构成了威胁;当缺陷环向方向位于管底时,轴向方向位于管道的大变形段内时,对断层内管道错动反应的影响要高于其他位置;在一定数值范围内,缺陷面积对管道在断层错动下的安全性影响较小。

Researched is stress-stain response of buried pipeline with volumetric defects in fault movement by using solid model and soil spring model, discussed are different stress and strain distribution in pipelines with and without defects and analyzed is effect of such factors as different defect depths, defect areas and locations on stress and strain distribution in pipeline top and bottom, established is the safety evaluation criterion for buried pipeline with defects in fault movement according to the results obtained from finite element models with different defect parameters and results of finite element analysis and circumferential fracture stress calculated as per ASME B31 G standard and analyzed is the safety of buried pipeline with defects in fault movement. The results show that defects with a depth more than 30% pipeline wall thickness will bring a threat to pipeline seismic safety in fault movement, depth and location of pipeline defects have a great effect on pipeline seismic safety when defects are located in pipeline bottom and defects have more effect on safety than any other defect factors and area of defects has relatively small effect on the safety provided it is within certain limits.