平面滑动型岩质边坡稳定性极限分析上限法

在极限分析理论框架体系的基础上,提出了平面滑动型岩质边坡极限分析上限法。该方法按照外力所做的功率等于内力所消耗的功率,即滑体处于极限状态时两功率相等的条件——虚功率方程,综合考虑作用在岩质边坡上的后缘裂缝静水压力、沿滑面扬压力、重力、水平地震作用力、锚固力等外力,按照强度折减法,推导得出了岩质边坡稳定性评价的极限分析上限解。锦屏一级水电站右岸泄洪洞引渠内侧工程边坡属于典型的多级台阶状岩质高边坡,该边坡岩体结构为层状结构,变形破坏模式为平面滑动。对引渠内侧岩质边坡稳定性分析结果表明,极限分析上限法对平面滑动型岩质边坡有较好的适用性。

METHOD OF UPPER BOUND LIMIT ANALYSIS FOR PLANE SLIDING OF ROCK SLOPES

In order to calculate and compare with the traditional rigid critical equilibrium method, this paper puts forward a new method of upper bound limit analysis for plane sliding of rock slope on the basis of limit analysis theory. By taking into consideration of the equivalent condition between the internal energy dissipation produced in the slip surface and the outer work done by external force, the upper bound solution for plane sliding of rock slope stability analysis can be deduced by means of strength reduction method. The new method can analyze different influencing factors including the hydrostatic pressure in back fissure, uplift pressure along slip surface, self-weight, horizontal seismic inertia force and anchorage force. The approaching channel inside slope of the spillway tunnel in the right bank of Jinping First Stage Hydropower Station is a typical multilevel step-shaped rock slope. The rock mass structure of the slope is stratified structure, and the potential mode of failure is plane sliding. The calculation results show that the new method of upper bound limit analysis is applicable to plane sliding of rock slope stability and is consistent with the rigid critical equilibrium method. Furthermore, it is a useful checking calculation approach for traditional method.