陡倾层状岩质斜坡极限平衡稳定分析
Limit equilibrium and stability analysis of steep stratified rock slope
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摘要: 针对自然界中的层状岩质滑坡绝大部分呈现出明显的三维形态特征,在倾倒破坏极限平衡二维推导分析方法的基础上,考虑层状岩质斜坡的三维受力状态,进行三维力系的简化与等效,提出了考虑三维受力的倾倒分析方法,在考虑真倾角方向的倾倒极限平衡分析中,将层状岩质滑坡近似为悬臂梁处理。并以重庆鸡冠岭滑坡为例进行验证分析。计算结果表明:①自然状态下,鸡冠岭斜坡处于稳定状态;②地下采空状态下,鸡冠岭煤层上覆岩层逐层发生倾倒破坏,并挤压下伏阻滑关键块体,导致关键块体剪出破坏后形成滑坡。该分析结果与实际情况基本一致。Abstract: With regard to the obvious three-dimensional characteristics for most natural stratified rock landslides, based on the two-dimensional derivation method for toppling-failure limit equilibrium considering three-dimensional stress state of stratified rock slope, simplification and equivalence are carried out of three-dimensional force system, and the toppling analysis method for three-dimensional stress is proposed. In the analysis of toppling limit equilibrium considering apparent dip, the stratified rock slope can be seen as cantilever beams. The landslide of Chongqing Jiguanling is taken as an example for verification and analysis. The calculated results show that: (1) Under the natural state, Jiguanling slope is in a stable state; (2) Under the underground mining state, overburden rocks of Jiguanling coal seam show toppling and failure layer by layer, and extrude the underlying anti-skid key blocks, leading to landslide after shear and failure of key blocks. The analysis results are basically consistent with the actual situation.