泾阳黄土抗剪强度的环剪试验研究

Research on ring-shear test of loess shear resistance strength in Jingyang

以泾阳滑带土为研究对象,采用HJ-1型环剪仪对泾阳县的重塑黄土进行了单级环剪试验,研究了不同含水率,干密度,剪切速度下重塑黄土在较大剪切位移下的强度变化规律。研究表明:土体应力-应变曲线呈软化现象;粘聚力和内摩擦角均随含水率的增加而降低;剪切速度越大的其达到峰值强度所需的剪切位移越小,粘聚力越大,但其对内摩擦角影响不显著;干密度与峰值强度呈正相关关系,对残余强度的影响不明显。脆性指数随含水率和剪切速率的增大而减小。

With the loess in Jingyang landslide zone as the research object,HJ-1type of ring shear apparatus is adopted to carry out the single grade ring shear tests of the remolded loess in Jingyang county to study the strength varying laws of remolded loess with different moisture contents,dry density and shear speed under the larger shear displacement.The research results indicate that the stress-strain curves of soil body appear to be weakened;the cohesion force and internal friction angles decrease with an increase in moisture contents.The larger the shear speed reaching the peak value is,the smaller the required shear displacement is and the larger the internal cohesion force is,but its effect upon the internal friction angle is not obvious.The dry density and peak value strength are found to be in positive correlative relation without obvious effect upon residual strength.The brittle index decreases with an increase moisture content and shear speed.