凹形边坡圆弧滑动模式稳定性控制机理研究

Research on stability control mechanism of concave slope with circular sliding mode

为了研究凹形边坡出现圆弧滑坡破坏时的稳定性控制机理,明确边坡形状差异对边坡稳定性的影响,基于瑞典圆弧法对滑体进行三维条分,并将侧向土压力纳入力学分析,推导出了适用于凹形边坡圆弧滑坡的三维稳定性分析方法.根据凹形边坡几何结构及地质参数,分析了凹形边坡曲率半径及上、下部拱高对边坡稳定性的影响规律.结果表明:从平直边坡向凹形边坡的过渡阶段,稳定系数先增大后减小,当上部拱高为边坡高度的1.5倍时,可使边坡稳定系数达到最大;随着边坡高度的增加,凹形端帮相比平直端帮稳定性提升的幅度逐步减小,凹形边坡形式对稳定性的提升作用在边坡高度较低时体现得较为明显.

In order to study the stability control mechanism of a concave slope with circular failure pattern and along with determining the influence caused by the difference slope shape on slope stability,the Sweden arc limit analysis method of slice in three-dimension model was used.By incorporating the lateral earth pressure into the mechanical analysis,the three dimensional stability analysis methods applicable for circular sliding in concave slope were deduced.Based on the geometric structure and geological parameters of the concave slope,the influence rule of curvature radius along with the top and bottom arch height on the concave slope stability were analyzed.The results show that the transition from a flat slope to the concave slope depicts a decrease in the factor of safety at first and when the upper arch radius is 1.5times the slope height,the factor of safety reaches it maximum.By contrast between the concave endslope and the straight end-slope is that the magnitude of the concave slope on the factor of safety gradually reduces with the increase in slope height.This indicates that the enhancing effect of a concave slope is apparent only with low slope height.