考虑土体强度各向异性的边坡稳定性分析

由于天然土体具有各向异性特征，应在边坡稳定性分析中考虑其影响. 对于黏土材料，将各向异性状态参数定义为材料组构张量与标准化偏应力张量之间的联合不变量，提出在抗剪强度指标c和φ中耦合该参数的表达式，并结合已有的试验结果验证了该公式的有效性. 将各向异性强度参数公式应用于边坡稳定分析，并进行大量计算. 研究表明：对于坡角为14°的缓坡，考虑强度各向异性的影响后，边坡安全系数降低可达22.0%；当坡角增加到55°时，各向同性与各向异性安全系数相对差值略大于8.0%. 即表明土体强度的各向异性对缓坡安全系数的影响比对陡坡的大，尤其对于高而平缓的边坡，这种影响应当引起重视.

A Stability Analysis of Slope Considering Strength Anisotropy in Soils

Due to the anisotropic characteristic of natural soils, their effects should be considered in slope stability analysis. For soils, the expressions of shear strength parameters c and φ are proposed by incorporating an anisotropic state scalar parameter which is a joint invariant of material fabric tensor and normalized deviatoric stress tensor, and the validity of the formula is verified by existing test results. The formula of anisotropic strength parameter is applied to slope stability analysis and a large number of calculations are performed. The results show that slope safety factor can be reduced by 22.0% after considering the anisotropy of strength for the gentle slope with an angle of 14°. When the slope angle is increased to 55°, the relative difference of safety factor in isotropy and anisotropy is slightly more than 8.0%. It indicates that the anisotropy of soil strength has a greater impact on the gentle slope than on the steep slope, especially for high and gentle slopes, which deserves attention.