持续暴雨作用下排土场层状碎石土边坡稳定性

为了研究排土场层状碎石土边坡在持续暴雨条件下的入渗过程及稳定性，推导了土体天然含水率、天然重度与天然体积含水量的换算公式，作为快速确定边坡土体初始基质吸力分布的依据。建立算例排土场有限元分析模型，进行降雨条件下饱和-非饱和渗流、孔压-应力耦合以及边坡稳定分析。结果表明：持续暴雨作用下排土场会在透水性最强的边坡浅层形成集中渗流通道，当坡底存在弱透水性土层时会切断渗流通道，导致雨水从坡脚涌出；排土场边坡位移在降雨期间不断增长，但增长速度越来越慢，雨后边坡位移立即开始减小；降雨初期边坡稳定性系数下降较快，边坡浅层渗流稳定后基本保持不变，雨后缓慢增大。排土场层状碎石土边坡在持续暴雨作用下容易在降雨中后期失稳。

Layered gravel soil slope stability of a waste dump considering long-term hard rain

In order to examine the effect of long-term hard rain on the layered gravel soil slope stability of a waste dump, the for-mula derivation relating natural water content, natural unit weight and natural volumetric water content was conducted to help to con-firm the initial suction of the slope rapidly. A numerical analysis model of a waste dump with a layered gravel soil slope based on the finite element method was established to analyze the saturated-unsaturated seepage, coupled stress-pore pressure and slope stability. The results show that a seepage channel will be formed in the slope surface due to its high permeability during the rain. If there exists a water-resisting soil layer in the bottom of the slope, water will come out from the slope toe. The displacement of the slope increases with a decreasing rate during the rain and decreases immediately after the rain. The stability coefficient of the slope decreases rapidly at the beginning of the rain. Then the stability coefficient barely changes till the rain stops as the seepage in the slope surface becomes stable. After the rain, the stability coefficient increases slowly. It is most possible for the layered gravel soil slope of a waste dump to fail in the middle and late stages of long-term hard rain.