持续小强度降雨入渗对非饱和土边坡稳定性的动态影响

以含水量作为土体抗剪强度的主要控制参量,分析了边坡含水量和抗剪强度随降雨时间的变化特性,建立了持续小强度降雨入渗条件下非饱和边坡土的总凝聚力和内摩擦角与时间的关系。随着降雨持续进行,边坡降雨影响区域扩大。通过FLAC3D进行强度折减,得到了持续降雨过程不同时间段的边坡动态安全系数和边坡失稳前的持续时间。工程计算结果表明,持续小强度降雨条件下边坡临界滑动面仍处在非饱和状态。

Dynamic Influence of Sustained Small Rainfall Infiltration on Stability of Unsaturated Soil Slope

Taking the moisture content as main control parameter of shear strength of the soil,we analyze the variational properties of moisture content and shear strength with the change of rainfall time during the small sustained rainfall infiltration,and establish the relationships between total cohesion as well as effective angle of friction and the time of sustained small-rainfall infiltration into an unsaturated slope.With the rainfall infiltration,the influence area of slope expands.Through the strength reduction method based on FLAC3D,the dynamic safety factor of slope in different time and the duration time before the failure of the slope are obtained.The results show that the slope critical sliding surface is yet unsaturated during a sustained small rainfall.