岩质边坡空间五面体类楔形体破坏的稳定性分析

Stability Analysis of Spatial Pentahedral Quasi-Wedge in Rock Slope

岩质边坡工程中存在着大量的楔形体失稳问题,国内外学者在楔形体破坏的滑动模式和稳定性分析方法已取得了丰富的研究成果.然而在工程实际中常形成与标准楔形体相似但存在差异的类楔形体,已有的楔形体稳定分析方法在分析此类问题时存在局限.本文针对由左结构面、右结构面、底结构面、坡面和坡顶面切割形成的空间五面体类楔形体,提出其滑动模式及相应的类楔形体运动学条件,对滑面上阻滑力方向进行假设后建立不同滑动模式下的安全系数求解显式表达,以最危险滑动模式对应的最小安全系数作为类楔形体的稳定性评价标准.采用Matlab软件对类楔形体的稳定性分析方法程序实现,数值算例的结果表明底结构面的引入对于滑动模式和稳定性评价结果存在重要影响.以某水电站进出水口左侧岸坡为工程实例进行应用研究,结果表明该边坡最危险的滑动模式为沿f10断层和1023高程底结构面的双向滑动,与边坡监测获取的变形方向一致.

There are a large number of wedge instability problems in rock slope engineering,and scholars at home and abroad have made many research results on the sliding mode and stability analysis methods of wedge failure.However,actual wedges which are similar to standard wedges but different from standard wedges are often occurred in engineering practice,and the existing wedge stability analysis methods have limitations in analyzing such problems.Aiming at the spatial pentahedral wedge-like body cut from the left structural plane,the right structural plane,the bottom structural plane,the slope surface and the top surface of the slope,its sliding mode and the corresponding kinematic conditions of the wedge-like body are put forward in this paper.Based on the assumption of the direction of the anti-skid force on the sliding surface,the explicit expression of the safety factor under different sliding modes is established,and the minimum safety factor corresponding to the most dangerous sliding mode is taken as the stability evaluation standard of the wedge-like body.The stability analysis method of wedge-like body is realized by using Matlab software.The results of numerical examples show that the introduction of bottom structural plane has an important influence on the sliding mode and stability evaluation results.Taking the left bank slope of the inlet and outlet of a hydropower station as an engineering example,the results show that the most dangerous sliding mode of the slope is the bi-directional sliding along the f10 fault and the bottom structural surface at the elevation of 1023m,which is consistent with the deformation direction obtained by slope monitoring.