穿越断层长大深埋隧洞动力非协调变形与破坏机制OA

The dynamic problem of long and large deep-buried fault-crossing tunnels under strong earthquake action has always been a research hotspot in deep underground engineering.Ensuring the safety and stable operation of the tunnel after an earthquake is the key to post-disaster rescue.To ex-plore the seismic dynamic response of the surrounding rock of a long and large deep-buried fault-cross-ing tunnel,based on the Xianglushan Tunnel project,a combination of indoor shaking table tests and theoretical analysis was adopted to conduct qualitative and quantitative analyses of the dynamic re-sponse of the tunnel surrounding rock under different fault dip angles,revealing the dynamic deforma-tion patterns of the long and large deep-buried fault-crossing tunnel under strong earthquake action.The results showed that under strong earthquake action,the dynamic response of the tunnel surround-ing rock was the most significant when the fault dip angle was 30°,and the changes in peak accelera-tion,peak strain,and peak displacement in the fault fracture zone were the most intense.Based on the shaking table test results,it was found that the dynamic response of the tunnel surrounding rock exhib-ited significant fault amplification and hanging wall effects,which consequently induced incompatible deformation of the tunnel surrounding rock.This incompatible deformation was the main cause of the deformation and failure of the long and large deep-buried fault-crossing tunnel.At the fault-crossing or near-fault locations of the Xianglushan Tunnel,the superimposed action of seismic loads and residual tensile-compressive stress induced cyclic back-and-forth tension,compression,and dislocation in the tunnel,leading to the development of longitudinal,transverse,and annular cracks,which may further cause large deformation and even failure.The research findings can provide guidance and reference for the stability analysis and safety assessment of long and large deep-buried tunnels in strong seismic ar-eas.