虎跳峡龙蟠右岸边坡稳定性的数值模拟

Numerical simulation on stability of right bank slope of Longpan in Tiger-Leaping gorge area

虎跳峡龙蟠右岸边坡的稳定性问题对拟建的虎跳峡水电站具有重要的意义。在钻探及平硐勘查过程中尚未发现该边坡有连续的滑动面,因此无法用传统的极限平衡法对其稳定性作出判定。本文运用有限元强度折减法对虎跳峡龙蟠右岸边坡的稳定性进行了稳定性分析研究,得出该边坡在现今应力场状态下的稳定性问题、潜在的破坏模式及相应的滑动面。此外,还结合离散元模拟进行了对比,结果表明有限元强度折减法和离散元方法获得的滑动面基本一致,增强了计算结果的可靠性。

The stability of the right bank slope of Longpan in Tiger-Leaping Gorge area is important to the building of the Tiger-Leaping Gorge reservoir. So it is important to select a proper method to obtain correct results. With the development of the calculations techniques, especially with the development of nonlinear mechanics of the rock and soil materials, the strength reduction FEM emerged as required. In the strength reduction FEM, it was not necessary to know where the slip surface was, and the initial geostatic stress could be included in the analysis which was more advantageous than the limited equilibrium method. The strength reduction FEM was used to study the stability of the right bank slope of Longpan in Tiger-Leaping Gorge area, and the stability coefficient of the slope under current stress state, the potential failure surface and its failure model. As a comparison, DEM analysis of the slope was executed. It was indicated that there was basic consistency between the results of the strength reduction FEM and DEM, which ensured the reliability of the result.