强降雨条件下非饱和双层土质边坡稳定性有限元分析

Finite Element Analysis of Stability of Unsaturated Double Layer Soil Slope under Heavy Rainfall

结合实际边坡工程项目,利用非饱和土的渗流理论和强度理论,建立非饱和双层土质边坡的二维有限元模型,分析非饱和土边坡在强降雨条件下孔隙水压力场的分布规律和稳定性变化规律,研究表明:非饱和土边坡的孔隙水压力场的分布与降雨持续时间有关,在降雨初期,边坡坡脚的孔隙水压力有所增加,随着降雨时间的增长,边坡的斜坡面和顶面的正孔隙水压力逐渐扩展并贯通,负孔隙水压力范围逐渐缩小;非饱和土双层土质边坡的稳定性系数随着降雨时间的增长大致呈线性减小。

In this paper,the two-dimensional finite element model of unsaturated double-layer soil slope is established based on the seepage theory and the strength theory of unsaturated soil.The distribution of pore water pressure field and the slop stability coefficient under the condition of heavy rainfalls are analyzed.The results show that the distribution of pore water pressure field of unsaturated soil slope is related to the duration of rainfall.In the early stage of rainfall,the pore water pressure at the toe of the slope increases.With the rainfall time increase,the positive pore water pressure on surface gradually expands and penetrates,and the range of negative pore water pressure gradually reduces.The stability coefficient of the unsaturated soil double-layer soil slope decreases linearly with the increase of rainfall time.