降雨条件下崩解炭质泥岩一维渗流特性研究

Research on Seepage Characteristics of One-dimensional Carbon Mudstone Disintegration under Rainfall Condition

为研究降雨条件下崩解炭质泥岩一维渗流特性,设计了一种测量崩解炭质泥岩在降雨条件下体积含水率变化规律的装置,通过设置3种降雨强度下崩解炭质泥岩土体的入渗试验,得到崩解炭质泥岩在不同降雨条件下随高程分布的各特征点体积含水率随时间的变化规律。同时,基于Geo-Studio软件中Seep模块对崩解炭质泥岩一维土柱进行数值模拟,验证了崩解炭质泥岩的渗流规律。结果表明：（1）崩解炭质泥岩路堤在降雨条件下沿高度方向的体积含水率变化呈现梯度变化规律,首先含水率由上至下依次升高达到平稳,随后底部土体率先饱和,最后全部土体达到饱和;（2）各特征点含水率达到平稳状态和饱和状态的时间与降雨强度成反比;（3）降雨过程中浸润线高度不断降低,浸润线的下降速度和拟合函数斜率均与降雨强度成正比,降雨强度越大浸润线到达碎石层的时间越短;（4）数值计算所得特征点含水率和浸润线的变化规律与试验结果基本一致,含水率变化更具规律性且浸润线深度在降雨中后期的结果较大。

In order to study the one-dimensional seepage characteristics of carbonaceous mudstone disintegration under rainfall conditions,a device of measuring the volume water content variation of the mudstone disintegration is designed,and by carrying outsoil infiltration experiment of disintegrating carbonaceous mudstoneunder three kinds of rainfall intensity,its change rules of thevolumetric water content changing with timeat characteristic points of accordingly distributed elevation under different rainfall conditions are obtained,and at the same time the Seep modular in Geo-Studio software is used to simulate the disintegration of carbonaceous mudstone based on one-dimensional soil column,the seepage law of carbonaceous mudstone disintegration is verified.The results show that：（1）the volumetric water content of disintegratingcarbonaceous mudstone embankment presents a gradient changing rule along the vertical direction：the moisture content first gradually increases from top to bottom in order to achieve stable;then the bottom soil becomes saturated,and then all soilsreach saturation;（2）the time of water content reaching steady state and saturation state is inversely proportional to rainfall intensity;（3）the height of wetting line decreases continuously during rainfall.The descending speed of wetting line and the slope of fitting function are directly proportional to rainfall intensity.The greater the rainfall intensity,the quicker the wetting line reaches the rock mass;and（4）the numerical variation and the test results of feature points and rate of water infiltration line is basically consistent,the change of water content is more regular and results in the later phase rainfall infiltration line have greater depth.