长大裂隙控滑机制及斜坡破坏模式分析

Evaluation of a Large Landslide with Large and Long Cracks and Failure Modes

以甘龙滑坡为例,基于滑坡灾害与地质构造的实测和三维数值模拟,分析了长大裂隙控制下的斜坡破坏模式。结果表明:①该滑坡为长大裂隙控制的V型拉剪式滑坡;②滑坡启动后Ⅰ区中部滑体沿长大裂隙切割岩体的临空面顺层滑动,后缘山体受牵引拉裂破坏,滑体遇左缘陡壁的阻挡,随即向滑坡右缘转向,并推挤剪切Ⅰ区前缘坡体,堆积至河道呈“7”型分布;③随裂隙的贯通长度与深度增加,切割岩体长度与深度增加,岩体临空面增大,与层面组合形成的楔形体增大,导致滑坡的边界附近的位移峰值和变形区均不同程度的增加,一旦发育出的贯通滑面的裂隙,便会形成类似楔形体的滑坡。

The slope failure modes under the control of long and large cracks in Ganlong landslide hazards are analyzed based on the measured geological tectonic structure and three-dimensional numerical simulation.The results show that:(1)the landslide is a V-shaped tensile shear landslide controlled by the long and large cracks;(2)after the landslide starts,the central sliding body in the I zone slides along the free face of the long and large cracks cut rock mass,and the mountain at the back edge is damaged by the traction and tension.The sliding body turns to the right edge of the landslide when it meets the barrier of the steep wall at the left edge,and then pushes and shears the front slope body in the I zone,and finally deposits to the channel in a“7”shape;(3)with the increase of the penetrating length and the depth of the fracture,the length and depth of the cut rock mass,the free surface of the rock mass,and the wedge form formed by the combination with the plane,the peak displacement and the deformation area near the boundary of the landslide increase in different degrees,once the cracks developed through the sliding surface,a wedge shaped landslide will be formed.