考虑含石量和降雨入渗角度的碳质泥岩土石混合体渗流特性

Seepage characteristics test of carbonaceous mudstone soil-rock mixture considering rock content and rainfall infiltration angle

为研究碳质泥岩土石混合体在降雨入渗作用下的渗流特性,通过自制试验装置开展了考虑不同含石量和入渗角度的降雨入渗模型试验,获取不同标高处试样体积含水率与基质吸力的变化规律。采用VAN-GENUCHTEN模型对试验结果进行拟合,得到碳质泥岩土石混合体的土水特性曲线。研究表明,降雨入渗时碳质泥岩土岩石混合物的体积含水率呈梯度变化趋势,土体由底层向上层逐渐达到饱和,含水率自上而下递增并达到稳定水平;碳质泥岩土石混合物的渗透系数随着岩石含量的增加而呈现出先降后升的趋势;降雨入渗角的增大可有效抑制降雨过程中样品内部基质吸力的降低;在排水过程中,土壤内部各标高的含水率随排水时间的变化呈现出指数函数关系,且含石量和降雨入渗角度都会对试样内部的颗粒流失产生影响。

To investigate the infiltration characteristics of carbonaceous mudstone soil-rock mixtures under the effect of rainfall infiltration,model tests considering rock contents and rainfall infiltration angles were carried out,and the various patterns of volumetric water content and matrix suction at each elevation within the sample were obtained.The VANGENUCHTEN model was used to fit the test results,helping to obatain the soil-water characteristic curves of carbonaceous mudstone soil-rock mixtures.The research results show that the volumetric water content of the carbonaceous mudstone soil-rock mixture was in a gradient trend,with the water content increasing from top to bottom and reaching a stable level,and the bottom sample saturated to the top.The permeability coefficient of the carbonaceous mudstone soil-rock mixture demonstrated a trend of first decreasing and then increasing with the increase of rock content.The rise of rainfall infiltration angle effectively inhibited the reduction of matrix suction inside the sample during the rainfall process.During the drainage process,the water content at each elevation within the sample showed an exponential function with the changing pattern of drainage time.Furthermore,the rock content and the rainfall infiltration angle affect the sample’s particle loss.