广东丘陵地区某岩质边坡稳定性分析及破坏机理研究

以广东丘陵地区某岩质边坡为例,采用定性和定量分析方法进行边坡稳定性分析及破坏机理研究。分析发现,定量分析中数值极限分析结果略高于刚体极限平衡法分析结果;通过现场采样,室内实验获得的土体基本物理力学参数普遍偏低,计算所得安全系数偏低;对边坡稳定性敏感因素c、φ、γs进行分析,总体而言φ值对边坡稳定性的影响较大。通过提高地下水位线的方式模拟暴雨工况,模拟分析结果偏低,过于保守,对后续边坡的防治易造成浪费。采用迈达斯SoilWorks软件,对边坡在暴雨工况下的降雨入渗情况进行分析,其结果显示暴雨工况下雨水入渗深度和边坡孔隙水压力变化均有限,这与实际情况基本相符。对于遇水易软化的岩质边坡,降雨因素对边坡稳定性影响较大,当降雨强度大于雨水入渗速率,在持续暴雨条件下,该类岩质边坡易发生由坡顶破坏引发的崩塌型破坏。

Taking a rock slope in hilly area of Guangdong as an example,qualitative and quantitative analysis methods are used to analyze the slope stability and study the failure mechanism.The analysis found that the numerical limit analysis results in the quantitative analysis were slightly higher than the rigid body limit equilibrium method analysis results;through on-site sampling,the basic physical and mechanical parameters of soil obtained in indoor experiments were generally low,and the calculated safety factor was low;the sensitivity factors for slope stability were analyzed by analyzing the factors c,φ,andγs;overall,theφvalue has a greater impact on slope stability.By increasing the groundwater level line to simulate heavy rain conditions,the simulation analysis results are low,too conservative,and easily cause waste in subsequent slope prevention and control.Midas SoilWorks software was used to analyze the rainfall infiltration of the slope under heavy rain conditions.The results showed that the rainfall infiltration depth and slope pore water pressure changes under heavy rain conditions are limited,which is basically consistent with the actual situation.For rock slopes that are easy to soften when exposed to water,rainfall factors have a great impact on slope stability.When the rainfall intensity is greater than the rainwater infiltration rate,under continuous heavy rain conditions,this kind of rock slopes are prone to collapse caused by slope top failure.