降雨入渗对边坡稳定影响的实例分析

以东江-深圳供水改造工程金湖泵站左岸边坡为例，分析影响边坡稳定的主要原因是地层岩性软弱，地区降雨量大，降雨入渗边坡后无法排出，聚集在混凝土防护层下，土体吸水软化，强度降低，导致坡面附近安全系数降低，边坡失稳。采用线弹性有限元及Mohr-Coulomb屈服准则进行土体应力、应变和破坏接近度计算，结果表明，边坡开挖后在自然状态下基本稳定，但随着降雨入渗边坡深度的增大，边坡坡面附近破坏接近度不断提高，破坏范围逐渐增大，边坡将町能由局部破坏发展为整体滑动破坏。

CASE STUDY ON INFLUENCE OF RAINFALL PERMEATION ON SLOPE STABILITY

Based on the case of the left bank slope of Jinghu pump station in Dongjiang-Shenzhen water supply remaking project, the factors influencing the slope stability are analyzed. The main causes of slope sliding are the soft rock strata in the slope and the large precipitation in this area. The water permeates into the slope body during the rain and can not be drained away quickly enough,so it concentrates under the concrete cover,and the rock is softened by it. Therefore,the safety factor of the slope decreases,and the slope begins sliding. Based on calculation of the stress, strain, and destruction approaching degree of the slope with the linear-elastic finite element method and Mohr-Coulomb yield criterion,a conclusion can be drawn that the slope in natural condition is basically safe,but,when the depth of the rainfall permeation increases,the destruction approaching degree near the slope surface increases,and the area of destruction increases gradually. The slope will develop from partial sliding to whole sliding.