逆断层作用下埋地管道局部屈曲行为研究

为研究断层作用下埋地管道的局部压溃和起皱行为，以黄土地层埋地管道为例，建立了管土耦合数值计算模型，分析了逆断层作用下埋地管道的变形及局部屈曲过程，研究了内压、径厚比及地层位错量对管道局部屈曲模式的影响规律。结果表明，随着地层位错量增大，断层面两侧管道出现应力集中，并逐渐演化为局部屈曲，埋地管道变形曲线由S形变为Z形，断层面两侧的管道变形并非呈对称或反对称分布，上盘区的管道屈曲现象较下盘区更为严重；地层位错量大于3倍管径时，管道轴向应变迅速增大；无压管道和低压管道的局部屈曲模式为压溃，而随着内压的增大，管壁屈曲模式由压溃变为起皱，且管道起皱幅度随着内压的增大而增大；上盘区管段屈曲部位与断层面之间距离受内压、径厚比影响较小，而压溃模式下下盘区屈曲部位与断层面之间的距离随着内压的增大而减小，起皱模式下二者之间的距离随着内压的增大而增大；不同地层位错量作用下，管道最大轴向应变随径厚比的变化呈现出不同变化规律。

Study on the Local Buckling Behavior of Buried Pipelines Under Reverse Faults

To investigate the local crushing and winkling behaviors of buried pipelines under reverse faults, this study has analyzed the buried pipelines in the loess layers and established a numerical calculation model for pipe-soil coupling. Furthermore, it has examined the process of deformation and local buckling in buried pipelines under reverse faults and evaluated the influence of internal pressure, diameter-to-thickness ratio, and the number of dislocations in the local buckling of the pipelines. Research results show that with an increase in the number of dislocations, stress concentration can be observed on the pipelines on both sides of the fault layer gradually leading to local buckling. The deformation curve of the buried pipeline changes from the S-shape to Z-shape. Moreover, the deformation of the pipeline on both sides of the fault plane is neither symmetrical nor anti-symmetric. The upper panel has experienced more serious pipe buckling than the lower panel. When the number of dislocations is three times higher than the diameter of the pipe, the axial strain of the pipeline increases rapidly. Pipelines with no pressure and low pressure have experienced crushing. As the internal pressure increases, crushing will further develop into wrinkling, and the wrinkle width of the pipe increases with the internal pressure. The distance between the buckling part of the upper panel and the fault plane is less affected by the internal pressure and the diameter-to-thickness ratio, while that between the buckling part of the lower panel and the fault plane reduces with the increase of the internal pressure under crushing and increases with the increase of internal pressure under wrinkling. The maximum axial strain of the pipeline demonstrates different patterns according to the variations in the diameter-to-thickness ratio and the number of dislocations.