不同断层对埋地管道受力性能的影响

为了研究埋地管道在不同形式断层作用下的受力性能,自制了土箱试验装置,借此装置模拟断层的错动,测量得到埋地管道在断层错动作用下的应变分布和整体变形特点,分析了管道轴向应变和竖向位移随断层错动量变化的特征,探究了断层错动量、管道埋深、管径、断层倾角等参数对埋地管道力学性能的影响规律,采用FEM有限元方法进行数值模拟分析,并与试验结果进行对比。结果表明:在该试验的参数范围内,随着断层错动量和管道埋深的增加,管道轴向应变增大;管径较大的管道,抵抗变形的能力较强;当断层倾角小于90°时,管道轴向峰值拉应变大于峰值压应变,此时管道以受拉为主;当断层倾角大于90°时,管道轴向峰值拉应变小于峰值压应变,此时管道以受压为主;对于走滑断层,管道轴向应变近似呈中心对称分布,两侧变形趋于一致。逆断层对于管道应变的影响最大,正断层其次,走滑断层对于管道应变的影响最小。(图17,表3,参21)

Influence of different faults on stress performance of buried pipelines

In order to study the stress performance of buried pipelines under different types of faulting,the soilbox test device was made to simulate the fault movement.Then,the strain distribution and overall deformation characteristics of buried pipelines under fault movement were obtained,the variation characteristics of axial strain and vertical displacement of pipelines with fault movement were analyzed,the influence rules of fault movement,pipe buried depth,pipe diameter and fault dip,etc.on the stress performance of buried pipelines were explored.The FEM method was used to conduct numerical simulation and its results were compared with test results.The results show that,within the parameter range of the test,the axial strain of the pipeline increases with the increase of fault movement and buried depth.Larger diameter pipelines will have stronger deformation resistance capability.When the fault dip is less than 90°,the axial peak tensile strain of the pipeline will be larger than the peak compressive strain,indicating that the tensile stress of the pipeline is dominant in this case.Similarly,when the fault dip exceeds 90°,the axial peak tensile strain of the pipeline will be smaller than the peak compressive strain,indicating a dominant compressive strain in that case.For strike-slip faults,the axial strain of the pipeline is approximately distributed in central symmetry,and the deformation on both sides tends to be consistent.Strike-slip fault has a minimal influence on the pipeline strain,followed by normal fault,and reverse fault has the greatest influence on the pipeline strain.(17 Figures,3 Tables,21 References)