考虑层间错动的顺层岩质边坡稳定性分析

Stability analysis of consequent rock slope considering slippage of bedding plane

渝怀线DK385+470～DK385+700段为典型的顺层岩质边坡,当采用滑面为直线型的刚体极限平衡法进行分析计算时,由于无法考虑滑体内的层间错动对边坡稳定性的影响,直接导致稳定系数计算结果偏大。根据极限分析上限法原理,结合工程实例,提出了考虑层间错动的顺层岩质边坡极限分析上限法,并推导了这种方法的稳定系数计算公式。该方法可以将层间错动产生的内能耗散计入到虚功率方程中,因而可以考虑层间错动对边坡稳定性的影响。以渝怀线典型顺层岩质边坡为例,采用刚体极限平衡法和极限分析上限法分别进行了稳定性分析计算,结果两种方法却得出了截然相反的结论。

As a typical consequent rock slope of Yuhuai Railway from DK385 ＋ 470 to DK385 ＋ 700, the failure mode is bedding slip with slippage of bedding plane. Because of not taking into account the contribution of slippage of bedding plane, the rigid critical equilibrium method for linear skip surface will cause the result of safety factor much great. According to the theory of upper bound limit analysis method, the author puts forward a new approach to deal with consequent rock slope stability analysis considering slippage of bedding plane, furthermore, computing formula of safety factor is deduced on the basis of engineering example. The new method can considerate the impact of slippage of bedding plane through calculating internal energy dissipation along bedding plane. As a case study, a typical consequent rock slope at Yuhuai Railway is computed by rigid limit equilibrium method and upper bound limit analysis method seperately. The results show that the two different methods can get quiet a contrary conclusion.