各向异性成层边坡的稳定性分析

Layered slope stability analysis considering anisotropy

为研究土体强度各向异性对成层边坡稳定性的影响,基于空心圆柱扭剪仪(HCA)试验得到的杭州软黏土不排水抗剪强度,并结合土体破坏微观机理,得到考虑土体各向异性的不排水抗剪强度公式,推导出与其对应的屈服准则;采用有限元强度折减法分析各向异性成层边坡稳定性。研究结果表明:随着上、下层强度比的改变,失稳破坏时会产生3种不同的滑动面形式;当土体呈现较强的各向异性时,不考虑强度各向异性的影响会使边坡安全系数计算结果不准确。

To study the influences of strength anisotropy on layered slope stability, a formula of anisotropic undrained shear strength and corresponding yield criteria was deduced based on the undrained shear strength of Hangzhou soft clay from hollow cylinder apparatus(HCA) test and microscopic failure mechanism of soil. The stability of anisotropic layered slope was analyzed by strength reduction method. The results show that with different strength ratios between the upper layer and lower layer, there are three types of mechanisms when failure occurs. The calculation results of slope safety factor tend to be inaccurate with no consideration of the influence of anisotropy when the soil exhibits strong anisotropy.