“挡墙溃屈”型滑坡锁固段抗滑稳定性研究

“挡墙溃屈”型滑坡是一类典型的大型岩质边坡破坏失稳模式,锁固段的物理力学性能为该类边坡稳定性的控制因素。依据此类边坡的受力特征,将上部坡体按其地质结构（如岩体层面）划分计算条块,采用极限分析上限法求出上部坡体对锁固段的作用力（方向和大小）。通过对锁固段的极限剪切平衡分析,推导了剪切破坏模式下锁固段的稳定性系数计算公式。以四川溪口滑坡为例进行了应用分析。首先根据稳定性系数与锁固段剪切面倾角的关系,确定锁固段最危险截面位置。进而定量分析了最危险截面宽度与边坡稳定状态的相关性。研究成果对“挡墙溃屈”型滑坡的稳定性评价及灾害控制具有较好的指导意义。

Anti-sliding stability of locked patch of rock slopes with landslide mode of retaining wall collapse

The landslide mode of retaining wall collapse is a kind of typical failure mode of large-scale rock slopes. The physical and mechanical properties of the locked patch play a key role in maintaining the stability of such slopes. Based on the force analysis of the slopes, the upper sliding mass can be divided into several calculation slices according to its geological structures (for example, bedding planes), and then the forces (including magnitude and direction) applied on the locked patch can be efficiently determined based on the upper bound method of limit analysis. On the basis of limit shear balance analysis, the safety factor of the locked patch with shear failure mode can be calculated. Xikou landslide in Sichuan is taken as a case study to verify the practical application of the theory proposed by the authors. Firstly, the most dangerous section in the locked patch can be obtained according to the relation between safety factor and dip angle of the shear plane. And then the relationship between the width of the most dangerous section and the safety factor is quantitatively analyzed. These results are of great significance for the stability evaluation and hazard control of the landslides with the failure mode of retaining wall collapse.