猴子岩水电站右坝肩卸荷岩体稳定性分析

A Stability Analysis of Unloading Rock Masses on Right Abutment of Houziyan Project

猴子岩水电站右坝肩边坡由于发育有大量断层和节理裂隙,存在影响边坡稳定的潜在不利块体。分别采用二维、三维的刚体极限平衡法和有限元法,分析边坡在天然工况和开挖工况下的稳定性,模拟分级开挖边坡的应力以及塑性区分布。计算结果表明:右岸边坡的潜在不稳定块体经加固后处于稳定状态,分级开挖过程中应力大小和分布位置未发生明显变化,且岩体的水平及竖向位移有逐渐减小的趋势,整个开挖过程边坡的塑性区尚未贯通,即右坝肩卸荷岩体边坡在天然工况和开挖工况下是稳定的。研究成果对指导工程实践具有重要的参考价值。

Due to the growth of a large number of faults and joints in right abutment rock masses, there exist many potential adverse blocks in the right slope of the Houziyan Project. Based on limit equilibrium method （LEM） and finite element method （FEM）, both 2-D and 3-D, a stability analysis is made of the slope under natural conditions and excavating conditions, at the same time, the stress and the distribution of plastic zones of the slope rock masses during step excavation are simulated. The results show that the reinforced supporting methods in right abutment rock masses make it safe to excavate downwards, the value and distribution of the stress do not change significantly. Furthermore, the horizontal displacement and vertical displacement decrease gradually during excavation, and the plastic zones do not cut thought the rock masses, either. So the right abutment slope keeps stable under either natural conditions or excavating conditions. The research findings are very important to engineering practice.