基于环剪试验的滑带土抗剪强度特性研究

以某水电站下游一大型滑坡千枚碎屑岩滑带土为研究对象,在室内模拟滑带土所受的天然状态条件,利用环剪仪研究了滑带土重塑样在不同法向应力与剪切速率下的抗剪强度特性。试验结果表明:滑带土的峰值强度和残余强度均随法向压力的增大而增大且有较强的线性关系,同时法向压力越大,试样达到残余强度所需要的剪切位移也会越小;剪切速率越大,滑带土的峰值强度也会越大,同时达到残余强度所需要的位移也会越大,但剪切速率大小对残余强度几乎没有影响,峰值强度参数与剪切速率之间可用对数关系拟合;剪切速率对滑带土的剪切面形态也有重要影响。

Research on shear strength characteristics of slide soil based on ring-shear test

Some phyllite slide zone soil of a large landslide at a hydropower station is studied by indoor simulation tests. The shear strength characteristics of remodeling slide zone soil under different normal stress and shear rate is studied by ring-shear apparatus. It is indicated that the peak shear strength and residual shear strength of the slide zone soil both increase linearly along with the increase of normal stress. Meanwhile, the greater the normal stress is, the smaller the shear displacement is when the sample reaches the residual strength. The greater the shear rate is, the greater the peak strength of the slide zone soil is and the greater the required displacement to reach the residual strength is, but the shear rate has little effect on the residual strength. The relationship between the peak strength and shear rate can be fitted by exponential equation. The shear rate also has big effect on the shear surface and its morphology.