降雨入渗对砂质边坡变形和稳定性的影响

基于砂质边坡的数值仿真模型,研究了降雨入渗对边坡稳定性和变形的影响规律。研究发现:边坡安全系数随着降雨持续时间和强度的增大呈现降低的趋势,随着边坡角度、高度的增加而减小,随着内摩擦角、黏聚力的增加而增大;而边坡高度和坡角对边坡滑动深度影响较小;土体内摩擦角大的边坡容易发生浅层滑坡,黏聚力大的边坡容易发生深层滑坡。随着降雨持时的增加,在边坡坡脚位置水平位移产生突变,为边坡最容易剪切滑出位置。抗滑桩的抗剪承载力越大边坡安全系数就越大,但承载力大的抗滑桩会加深滑裂面的位置;抗滑桩在加固位置位于边坡中下部时的安全系数比设置在上部时增加2%~5%。因此,在不改变危险滑裂面的情况下,合理设计抗滑桩强度可以提高边坡安全系数。

Influence of Rainfall Infiltration of Sandy Slope on Deformation and Stability

The influence of rainfall infiltration on stability and deformation of sandy slope are studied based on the numerical simulation model.The results show that with the increase of rainfall duration and intensity，slope safety factor tends to decrease.The safety factor decreases with the slope angle and height increase，while it increases with the increase of internal friction angle and cohesion.The height and angle of slope have less effect on the depth of slope sliding，and the slope with large internal friction angle are more likely to happen the shallow slide，while the slope with high cohesion are more likely to happen deep landslide.With the increase of rainfall duration，horizontal displacement at the foot of the slope appears sudden change，and this position is most likely to produce shear sliding.The greater of the shear bearing capacity of the slope，the greater of the safety factor is.However，anti-slide pile with large bearing capacity will deepen the critical slip surface.Safety coefficient of the slope reinforced by anti-slide pile at the bottom of the slope increased by 2%~5% than that at the top of the slope.Thus，the reasonable design strength of the anti-slide pile could increase the slope safety factor without changing the dangerous slip crack surface.