岩质边坡稳定塑性极限分析方法——斜分条法

基于塑性极限分析上限定理,依据岩质边坡沿某一滑裂面滑动破坏时,在其内部产生沿陡倾角结构面(断层、节理和层面)的剪切破坏现象,建立了岩质边坡极限分析斜分条法破坏模式。进一步根据滑体处于极限状态时的虚功率方程,推导得出了斜分条后岩质边坡的塑性极限分析稳定系数计算公式。采用超载系数的方法,将稳定系数表示在块体所受的极限荷载,避免了隐式出现,有效地简化了公式推导。以锦屏一级水电站右岸边坡为例进行了稳定性分析。计算表明,结论较为合理,对于具有倾斜界面的岩质边坡稳定性评价具有重要意义。

Rock slope stability analysis based on plasticity limit theory——method of slices with inclined interfaces

Based on plasticity limit analysis by upper bound theorem,a new method to analyze rock slope stability was put forward.It was known that the inside of rock mass would generate shear failure along some old steep discontinuities(faults,joints and bedding planes) when sliding damage took place.According to the phenomena and virtual work rate equation in limit state,a different failure mode of inclined slices technique was established,and the computing formula of safety factor was also derived using the theory of plasticity limit analysis.By means of overload factor,the safety factor of slope stability could be easily expressed by the critical loads.As a result,not only the implicit expression could be avoided,but also the safety factor could be calculated simply and effectively.As a practical engineering example,the right bank slope of Jinping First Stage Hydro power station was analyzed.It was shown that the new method was accurate and significant for rock slope with inclined interfaces.