极端灾害天气下临河岩质边坡的倾覆稳定性分析

Overturning Stability Analysis of Rock Slope along River Under Extreme Disasters Weather

基于改进的水压分布假设,建立了临河岩质边坡在冻胀作用、静水压力和流水淘蚀等多因素影响下失稳的概化理论模型,并利用极限平衡理论推导出了极端天气下临河岩质边坡倾覆稳定性的无量纲表达式。重点分析了各影响因素对边坡倾覆稳定性的影响,绘制了饱水岩质边坡倾覆稳定性系数与坡高、坡角、临河水位以及水平淘蚀距离之间的关系图;同时分析了非饱水状态下边坡的倾覆稳定性系数与各影响因素的关系。算例分析表明:在极端天气的影响下,出溜缝未堵塞边坡的倾覆稳定性发生了很大的变化,其随着临河水位的升高先减小后增大,随淘蚀距离的增加而减低,随坡角、坡高的增加而增加,当坡高较低时,随冻深的增加而减低,当坡高较高时,随冻深的增加而增大。

Based on the assumption of improved groundwater pressure distribution,a model of rock slope instability generalizability theory along river under the multiple factors of frost heaving,hydrostatic pressureand stream erosion at the slope is established,and the calculation formula of overturning stability factor of rock slope along river is derived by using limit equilibrium method. The model focuses on the influence of various factors on overturning stability of rock slope along river,and diagrams get drawn which express the relationship between slope height,slope angle,the water level,stream erosion distance and the coefficients of overturning stability when the rock slope is saturated; Thenthe relationship,between overturning stability of rock slope along river and various influence factor,is analyzed when the rock slope along river is unsaturated. The calculation example analysis shows that： the overturning stability of slope where outflow seam is unblocked has been greatly changed under the influence of extreme disasters weather,it decreases first,then increases as the water level along river rises; it decreases as the distance of eclipse increases; it increases as slope angle and height increases; when slope height keeps low,it decreases as frost depth increases,otherwise,it increases as frost depth increases.