大型岩质滑坡地震变形破坏过程物理试验与数值模拟研究

PHYSICAL MODELING AND NUMERICAL SIMULATION OF DEFORMATION AND FAILURE PROCESS OF LARGE ROCKSLIDE IN EARTHQUAKE

以汶川地震触发的大光包岩质滑坡为例,结合野外现场调查,以其地质结果为背景,建立起破坏前的物理模型和三维数值模型,利用振动试验台和数值计算方法对滑坡变形破坏过程进行了研究。物理试验与数值模拟方法相互验证,取得了较为一致的结果。研究结果表明:该滑坡的破坏模式为坡体顶部与中部拉张贯穿破坏→中部沿层面滑移→前缘剪切破坏,中部拉裂缝与主滑面首先形成滑动边界,前缘首先滑出;滑坡变形过程中的加速度与速度响应研究表明其放大效应明显。同时,通过对比基岩与滑带加速度与速度放大系数,显示了结构面对斜坡变形破坏过程的控制作用。

Earthquake is one of the main factors of the generation of a landslide.This paper takes the Daguangbao rockslide triggered by the Ms 8.0 Wenchuan earthquake for example.Based on site investigation,the physical model experiments and numerical model are built to simulate the deformation and failure process of the rockslide.The results of model test match the results of numerical simulation well.The results show that failure model of slide was that the toe and the middle of the slide was shear failure and the top of the slide was tension failure.The tension cracks of slope and the shear oblique layer on the bottom composed the slide boundary.Through the research of acceleration and velocity response,the calculated also resulted that the structural plane played a controlling role in the dynamic response of the rock slope.