穿越走滑断层埋地管道应变特性的试验研究

穿越断层的埋地管道在地震等外力作用下会发生屈曲、断裂等破坏,研究走滑断层作用下埋地管道的应变特性,对管道工程的设计和防护等具有重要意义.借助前期设计的场地变形组合试验装置,针对走滑断层的作用特点,模拟穿越此断层的埋地管道受力情况,测得随断层错动管道的应变分布及管道周边土体压力变化,分析管径变化对应变和管周土压力的影响,得出管道变形区域的范围.试验结果表明:断层面附近的管道在断层走滑错动过程中受到轴向拉力或压力的作用,其变形沿断层面与管道交点近似呈中心对称;距离断层较远的管道随土体一起运动,不会产生变形,即管道变形在断层附近的一定区域内;管径越大,受断层运动影响的管道变形区域越小;随断层错动位移量的增大,断层附近管道周围土压力和管道的轴向应变都增大,且随管道直径的增大管周土压力和轴向应变减少.

Experimental research on strain properties of buried pipelines at strike-slip fault crossings

Buried pipelines at strike-slip fault crossing would be buckling,rupture and engender other damages under the action of external forces such as earthquake.It is very important for the design and protection of pipe engineering to study strain properties of buried pipelines subjected to strike-slip faults.Stresses of buried pipelines crossing strike-slip faults are simulated by the aid of the early designed experimental apparatus for combined ground deformation,and strain distribution and change of soil pressure around pipeline are measured.Also,effects of diameters of pipeline on axial strain and soil pressure around pipelines are analyzed,and the deformation region of pipelines are obtained.The test results indicate that pipelines near fault plane are subjected to axial tension or compression during faults slipping along the fault plane,and their deformations are approximately centrally symmetrical along intersection point of the fault planes and pipelines.The pipelines far from fault move with soil so that they are not deformed,thus,the deformations of pipelines occur in a certain region near the fault.The larger diameter of a pipeline is,the smaller deformation region affected by fault is.Soil pressure around the pipelines and the axial strain of pipelines near the fault increase with the increase of the displacement of fault slipping.Furthermore,axial strain of pipelines and soil pressure around pipelines decrease with the increase of the pipeline diameter.