排土场边坡渗流特征的降雨模型试验及数值分析

Rainfall Model Test and Numerical Analysis of Seepage Characteristics of Dump Slope

为研究降雨条件下边坡渗流特征的变化规律,以某双采场排土场为研究对象,采用室内降雨模型试验分析不同土料渗流场的变化规律,同时利用FLAC3D数值模拟软件对三维排土场模型开展降雨入渗模拟。结果表明:降雨作用下,土料边坡模型含水率、基质吸力、孔隙水压力的响应特征显著,含水率的响应优先级最高;相较于2#采场土料,1#采场土料的渗透性更强,其湿润锋、饱和度、孔隙水压力的扩展区域更大;渗透性强的土体容易发生滑坡破坏,渗透性能弱的土体容易产生冲沟裂纹。基质吸力会不断减小,基质吸力下降会影响土体的抗剪强度指标,下降幅度较大易产生滑坡破坏现象。通过三维模型降雨模拟可知,降雨对边坡渗流特征影响较大,降雨导致排土区域孔隙水压力不断增大,从而可能造成滑坡的产生。

In order to study the variation law of slope seepage characteristics under rainfall conditions,taking a stope dump as the research object,the indoor rainfall model test was used to analyze the variation law of seepage field of different soil materials.At the same time,FLAC3D numerical simulation software was used to simulate rainfall infiltration of three-dimensional dump model.The results are concluded as follows.Firstly,under the action of rainfall,the response characteristics of moisture content,matrix suction and pore water pressure of soil slope model are significant,and the response priority of moisture content is the highest.Secondly,compared with 2~#stope soil material,1~#stope soil material has stronger permeability,and the expansion area of wetting front,saturation and pore water pressure is larger.Furthermore,the soil with strong permeability is prone to landslide,and the soil with weak permeability is prone to gully cracks.The matrix suction will continue to decrease,and the decrease of matrix suction will affect the shear strength index of the soil,and the decrease is easy to cause landslides.Through the rainfall simulation of the three-dimensional model,it can be seen that rainfall has a great influence on the seepage characteristics of the slope.Rainfall causes the pore water pressure in the dumping area to increase continuously,which may cause landslides.