雅鲁藏布江缝合带大峡谷段震裂山体发育特征与失稳机理OA

Based on field geological investigations and existing research findings,this study systematically ana-lyzes the developmental characteristics of seismically fractured mountains within the Great Canyon Section of Yarlung Zangbo Suture Belt.Taking the Badenze mountain,located in Motuo,as a typical case,it summarizes the disaster-prone geological conditions from three aspects:lithological assemblage,tectonic activity,and rock mass structure.The mechanism of seismically fractured mountain instability under strong seismic activity was further investigated.The results indicate that the Great Canyon segment of the Yarlung Tsangpo Suture Belt is predominantly composed of the Aniqiao Formation,tectonic mélange,and Gangdese magmatic complex.Sig-nificant spatial heterogeneity and intense deformation among these lithologies,coupled with severe dissection by active faults such as the Motuo Fault,have resulted in extensively fractured rock masses with highly devel-oped structural planes.Consequently,historical mega-earthquakes,particularly the 1950 Ms 8.6 Chayu earth-quake,exacerbated structural relaxation and triggered widespread rock mass cavitation,thereby significantly compromising slope stability and rendering it highly susceptible to large-scale catastrophic failures under renewed strong seismic disturbances.Based on these findings,targeted strategies for disaster risk mitigation are proposed.Nevertheless,current research on the instability mechanisms of seismically fractured mountains in suture zones remains insufficient.Future studies urgently require the development of refined geomechanical models to elucidate the damage evolution mechanisms of heterogeneous mélange and clarify the dynamic response of cross-fault mountain masses under strong seismic shaking.This will provide critical support for the prevention and control of catastrophic geohazards across the Qinghai-Tibet Plateau.