双重介质模型在考虑岩块孔隙渗流的条件下，一定程度上刻画了岩体裂隙渗流的优先流现象。为研究双重介质模型下裂隙岩质边坡的渗流特性，以二维边坡为例，基于双重介质模型，研究了不同降雨条件下孔隙域和裂隙域的入渗边界条件及2者之间的关系，推导了裂隙域等效降雨强度方程，利用COMSOL Multiphysics有限元数值计算软件，定量分析了2种降雨条件(长而弱、短而强)下，孔隙域和裂隙域的入渗规律及水交换规律，并分别采用强度折减法和局部安全系数法分析了2种降雨入渗对边坡稳定性的影响。结果表明：① 双重介质模型下，孔隙域和裂隙域入渗边界条件变得更为复杂，边界条件的转换需要综合考虑降雨强度、裂隙域等效降雨强度及两域的饱和渗透系数之间的关系。② 2 mm/h的降雨强度下，雨水大部分通过孔隙域向下入渗，孔隙水压力的变化主要体现在孔隙域，水交换主要由孔隙域向裂隙域中流动，水交换项的值较小;边坡位移较大的区域从坡顶贯穿至坡脚，可能发生整体滑动，降雨结束后边坡的安全系数从1.92降至1.89，降低了1.56%，潜在破坏区域体积增量较小。③ 20 mm/h的降雨强度下，雨水几乎全部通过裂隙域向下入渗，孔隙水压力的变化主要体现在裂隙域，水交换主要由裂隙域向孔隙域中流动，水交换项的值较大;位移较大的区域在边坡中下部及坡脚处，可能发生牵引式滑动，降雨结束后边坡的安全系数从1.920降至1.757，降低了8.49%，坡脚处的潜在破坏区域体积增量较大。

The dual medium model characterizes the preferential flow phenomenon of rock fracture seepage to some extent under the condition of considering rock pore seepage.In order to study the seepage characteristics of fractured rock slopes under the dual medium model,taking the two-dimensional slope as an example,based on the dual media model theory,the infiltration boundary conditions of pore domain and fissure domain under different rainfall conditions and the relationship between them were studied,and the equivalent rainfall intensity equation of fissure domain was derived.The COMSOL Multiphysics finite element numerical calculation software was used to quantitatively analyze the law of infiltration and water exchange in the pore area and fissure area under different rainfall conditions,and the strength reduction method and the local safety factor method were used to analyze the impact of rainfall on slope stability.The conclusion are as follows:① the boundary conditions of infiltration in the pore and fissure domains become more complicated under the dual-medium model.The conversion of the boundary conditions needs to comprehensively consider the relationship between the rainfall intensity,the equivalent rainfall intensity in the fissure domain and the saturation permeability coefficient of the two domains.② Most of the rainwater infiltrates through the pore domain,and the change of pore water pressure is mainly reflected in the pore domain under the rainfall intensity of 2 mm/h.The water exchange which is small mainly flows from pore domain to fissure domain.The area with large displacement penetrates from the top to the foot of the slope,and overall failure may occur.After the rain,the safety factor of the slope decreases 1.56% from 1.92 to 1.89,and the increase of volume of potential damage area is smaller.③ Almost all rainwater infiltrates through the fissure domain,and the change of pore water pressure is mainly reflected in the fissure domain.The water exchange which is large mainly flows from fissure domain to pore domain.The area with large displacement is in the middle and lower part and the foot of the slope,and traction failure may occur.After the rain,the safety factor of the slope decreases 8.49% from 1.92 to 1.757,and the increase of volume of potential damage area is larger.

1 双重介质模型渗流理论

   1.1 双重介质下渗流耦合方程

   1.2 入渗边界条件

2 算例分析

   2.1 模型及参数

   2.2 体积含水率分析

   2.3 入渗率及孔隙水压力分析

   2.4 入渗量及渗流量分析

   2.5 水交换分析

   2.6 稳定性分析

3 讨论

4 结论