基坑边坡渗流稳定及可靠度研究

Study on the Reliability of Seepage Stability of Foundation Pit Slope

针对以往研究较少关注基坑边坡的渗流稳定可靠度,以某经济开发区的一典型基坑边坡为例,利用Geostudio的渗流模块及边坡稳定模块对不同强度降雨条件下的基坑边坡孔压力及安全系数变化规律进行了数值模拟,同时得到了基坑边坡的失效概率。结果表明,不管何种降雨强度,降雨期间,各监测点的孔压力不断增大,监测点高程越小,孔压力增大幅度越小;降雨停止后,各监测点的孔压力不断减小,监测点高程越小,最终的孔压力越大。降雨强度越大,各监测点孔压力上升速度越快;降雨结束时的孔压力越大,停雨后的孔压力减小速率最快。降雨期间基坑边坡的安全系数不断减小,降雨停止后其安全系数逐渐增大。降雨强度越大,基坑边坡的最小安全系数越小。随着降雨强度的增加,基坑边坡的稳定性逐渐减小,而其滑坡的概率逐渐增大。

In view of the fact that little attention has been paid to the reliability of seepage stability of foundation pit slope in the past,taking a typical foundation pit slope in an economic development zone as an example,the variation of pore pressure and safety factor of slope under different intensity rainfall conditions is simulated by using Geostudio seepage module and slope stability module,and the failure probability of slope is obtained.The results show that whatever the rainfall inten⁃sity is,during rainfall,the hole pressure of each monitoring point increases continuously.The smaller the elevation of the monitoring point is,the less the hole pressure increases.After the rainfall stops,the hole pressure of each monitoring point decreases continuously.The smaller the elevation of the monitoring point is,the greater the final hole pressure is.The great⁃er the rainfall intensity is,the faster the hole pressure of each monitoring point rises.The greater the hole pressure is when the rain stops,the fastest the reduce rate of hole pressure is after the rain.The safety factor of foundation pit slope gradually decreases during the rainfall and then gradually increases after the rain stops.The greater the rainfall intensity is,the smaller the smallest safety factor of foundation pit slope is.Along with the rainfall intensity increases,the stability of foundation pit slope gradually decreases while the probability of seepage gradually increases.