土体含水率与滑坡风险相关性实验研究

降雨入渗容易造成边坡滑坡自然灾害,含水率是影响土体抗剪强度的关键因素之一。本文以滑坡区红黏土为研究对象,制作了5组不同含水率的土样,并在不同垂直压力下进行快速剪切实验,得到每组对应的剪切强度参数,研究了含水率与剪切强度参数之间的关系。利用实验所得到的土工参数进行高地下水位边坡稳定性数值模拟,拟合得到边坡坡顶含水率与边坡安全系数的关系。结果表明:含水率从10%增加到25%,红黏土强度指标粘聚力、内摩擦角约分别下降50%和30%;含水率与粘聚力和内摩擦角间均呈半对数关系;边坡坡顶含水率增加导致边坡安全系数近似成二次曲线下降趋势。

Experimental study on correlation between soil moisture content and landslide risk

Rainfall infiltration is easy to cause natural disasters in slope landslides,and moisture content is one of the key factors affecting the shear strength of soils.In this paper,five groups of red clay samples in landslide area with different moisture contents are prepared.Under different vertical pressures,we have carried out rapid shearing tests and obtained corresponding shear strength parameters for each group.In the meantime,the relationship between moisture content and shear strength is studied.Based on the geotechnical parameters obtained from the experiments,we have numerically simulated the stability of the high groundwater level slope,and obtained the relationship between the moisture content and the safety factor.The result shows that as the moisture content increases from 10%to 25%,the cohesion and internal friction angle of the red clay strength index decrease by about 50%and 30%,respectively.The moisture content has a semi-logarithmic relationship with the cohesion and internal friction angle.Moreover,the increase in moisture content leads to a quadratic curve decline in the safety factor of the high groundwater level slope.