折线滑面渐进破坏特性及稳定性分析方法研究

Progressive failure characteristics and stability analysis of folded sliding surface

为了研究折线滑面渐进破坏过程的稳定性分析方法,掌握滑体发育过程中的时效稳定系数变化规律,对不同岩性渐进破坏过程中的抗剪强度及力学参数退化机理进行研究,基于下滑力、抗滑力及不平衡推力法的基本计算原理,推导出折线滑面渐进破坏过程的时效稳定系数计算公式,并对布沼坝露天矿西帮边坡稳定性进行分析.结果表明:在渐进破坏过程中,边坡稳定系数随硬岩破裂区长度的增大呈线性递减,随软岩塑性贯通区长度的增大呈指数递减.缓帮对于边坡稳定性的增强效果在硬岩破裂阶段较为明显,在软岩贯通阶段相对较弱,边坡角每降低1°,稳定系数平均提高2.8%.削坡减载使边坡稳定系数呈现出二次线性增长,当边坡高度降低40m时,边坡稳定系数为1.124,相对于初始状态提高了12.7%.

This paper aims at studying the analytical method of the stability during the progressive failure of folded sliding surface as well as the aging coefficient of sliding body development.Using basic calculation principle of sliding force,sliding resistance and imbalance thrust force method,the degradation characteristics of shear strength and mechanical parameters in different lithological gradual failure processes are investigated.A calculation method of aging stability coefficient is proposed to analyze the stability of west slope of an open pit mine in Buzhaoba.Results show that during progressive failure,the slope stability coefficient decreases linearly with increasing length of hard rock rupture zone,whilst decreases exponentially with increasing plastic penetration length of soft rock.An obvious enhancing effect of slow slope on slope stability can be seen for hard rock rupture phase,however,this effect is weaker for soft rock penetration phase.1degree of decrease in slope angle is corresponding to 2.8%increase of stability coefficient.For instance,when the slope height is reduced by 40 m,the stability factor increased by 12.7%,indicating the cutting slope and reduced load contribute to a quadratic lin-ear growth of slope stability coefficient.