降雨要素对土质边坡稳定性的影响分析

Soil slope stability analysis under the condition of rainfall infiltration

基于饱和-非饱和渗流理论与非饱和土的抗剪强度理论,研究了降雨强度、降雨历时等降雨要素对土质边坡安全系数的影响规律,并且重点对短时强降雨、长时弱降雨2种降雨形式进行了对比分析.结果表明:在饱和渗透系数一定的情况下,安全系数随着降雨强度、降雨历时的增加而不断减小,但在降雨结束后,安全系数又随时间的增长开始增大;短时强降雨下边坡上部土体更容易达到饱和,而长时弱降雨对边坡土体的影响更大,两者的稳定性都大大降低,但长时弱降雨下的滑坡危害程度更大.

Based on saturated-unsaturated seepage theory and the shear strength theory,we study the effect of rainfall intensity and rainfall duration on the soil slope safety,focusing on the comparison and analysis of the short time heavy rainfall and long time weak rainfall. Analysis results show that for a fixed saturated permeability coefficient,safety coefficient decreases as the rainfall intensity and rainfall duration increase,but it increases with time after rain; short time heavy rains make top soil of the down slope more likely to achieve saturation,and long time weak rainfalls have greater influence on the slope soil,the stability are greatly reduced in both cases. Long time weak rainfall increases the chance of landslide.