【摘要】 "5.12"汶川地震诱发了数以万计的滑坡灾害,其中仅大型滑坡就上百处.通过对汶川地震诱发的20余处大型滑坡的变形破坏特征进行深入调研,结合振动台试验和数值模拟等手段,发现汶川地震诱发大型滑坡的变形破坏模式和内在力学机制与常规重力作用下滑坡机制具有显著的不同.在强震条件下,斜坡中上部地震水平加速度可超过1g,其地震水平惯性力远远超过岩体的抗拉强度,地震作用首先在坡体后缘形成与坡面平行且陡倾坡外的深大拉裂缝,随后拉裂岩体的底部产生剪切滑移,最终形成滑坡.在强震条件下,斜坡岩体最基本的变形破坏单元就是拉裂和剪切滑移,且以拉裂占主导.不同的斜坡结构,其底部剪切滑移会沿不同的结构面发生.根据滑源区所处的地质环境条件、坡体结构以及岩性组合特征,将汶川地震诱发的大型滑坡划分为五类成因模式:拉裂—顺走向滑移型、拉裂—顺层(倾向)滑移型、拉裂—水平滑移型、拉裂—散体滑移型、拉裂—剪断滑移型.更多还原

【Abstract】 The "5·12" Wenchuan earthquake induced thousands of landslides,including hundreds of large-scale ones.The deformation and destroy characteristics of 20 large-scale landslides induced by Wenchuan earthquake found in our in-depth investigation and extensive survey,combined with the tools of shaking table test and numerical simulation,we find that their deformation and destroy model and intrinsic mechanical mechanism Wenchuan earthquake are significantly different from those of landsides induced by routine gravity.On the condition of strong shock,the earthquake-horizontal acceleration on the middle-top of the declivity can exceed 1g,and its earthquake horizontal inertia enormously exceeds the tension strength of the rock mass.Seismic action firstly shaped a deep large fissure which was parallel to the clinohedron on the back of the slope,and then the bottom of the pull-apart rock mass engendered shearing glide,finally,there induced landslide.On the condition of strong shock,the most essential deformation and destroy element of the slope rock mass are tension-cracks and shearing glide,and mainly dominated by tension-cracks.With different slope structures,the bottom shearing glide occurs with different discontinuities.According to the geological environment of the landsliding source region as well as the characteristics of the slope form and lithological association,this paper divides the large-scale landslides induced by Wenchuan earthquake into five genetic types,namely,tension-cracking and consequent sliding,tension-cracking and bedding sliding,tension-cracking and horizontal sliding,tension-cracking and scattering sliding and tension-cracking and shearing sliding.更多还原