关键词: 顺层岩坡, 预应力锚索, 地震作用, 极限分析, 安全系数

Abstract: An improved limit analysis method was proposed for the bedding rock slope reinforced by pre-stressed anchor cables under seismic loads, according to their typical models. Especially, this improved method considered the force variation of anchor cables when the slope was in a limit equilibrium state. First, based on the assumption of the rigid rock mass and the limit equilibrium method, the formula of the force variation of anchor cables was derived according to the force changes of anchor cables during the sliding process. In this study, the earthquake effect only referred to the influence of the transmitted waves on the stability of the slope when the transmitted waves were generated in the propagation process of the seismic wave into the sliding surface. Second, from the perspective of power, a theoretical formula was derived for calculating the dynamic safety factor of bedding rock slope by combing with the upper bound limit analysis method and the strength reduction method. Finally, in the case study, we analyzed the difference of dynamic safety factors by using two methods with or without considering force variations of anchor cables in the sliding process. Moreover, this study discussed the calculation results by using these two methods under the variations of amplitudes and incident angles of P wave, and the variations of cohesion and friction angles of sliding surface, respectively. The results show that the variation laws of dynamic safety factors obtained by these two methods are consistent. However, the variation degree of dynamic safety factors by the improved method is significantly lower, which indicates that the anti-seismic effect of anchor cables has been fully reflected. This study can provide references for the design and the stability analysis of bedding rock slope reinforced by pre-stressed anchor cables under seismic loads.

Key words: bedding rock slope, prestressed anchor cable, seismic loads, upper bound limit analysis, safety factor