暴雨及久雨作用下东岭信滑坡堆积体的渗流特性及稳定性分析

Seepage Characteristics and Stability Analysis of Donglingxin Landslide Under Heavy Rain and Long Rain

暴雨和久雨是影响滑坡稳定性的重要因素.选取东岭信滑坡堆积体典型剖面,研究其在降雨条件下的稳定性演化机制.基于非饱和渗流基本理论研究了相同雨量、不同雨型下堆积体的渗流特性,并基于渗流场计算结果采用极限平衡法计算了安全系数.根据计算结果,从降雨过程中和降雨后两个角度分析了堆积体内部渗流场与稳定性对不同降雨条件的响应规律.结果表明,暴雨较久雨对堆积体渗流场的影响更大,并表现出强烈滞后性;而久雨较暴雨对堆积体稳定性影响更大,且表现出较弱滞后性;暴雨易在降雨结束后造成滑坡,而久雨更有可能在降雨过程中造成滑坡.

Heavy rain and long rain are important factors which affect the stability of landslide.A typical section of Donglingxin landslide deposit was selected to study the evolution mechanism of its stability under rainfall conditions.Based on the theory of unsaturated seepage,the permeability characteristics of the slope deposit under the conditions of same total rainfall and different rain patterns were studied,and the safety factor was calculated based on the result of seepage calculation through the limit equilibrium method.Then,the response regularity of the seepage field and stability of the slope deposit under different rainfall conditions were analyzed from the two aspects of during rainfall process and after rainfall.The results show that heavy rain has more influence on the seepage field of the slope deposit and has a stronger hysteresis than long rain,while long rain has more influence on the stability and has a weaker hysteresis.Heavy rain is more likely to cause landslide after rainfall,while long rain often causes landslide during rainfall process.