基于非线性破坏准则的边坡稳定性分析

Baker提出的非线性破坏准则是一种广义的岩土体强度准则,常规的M-C强度准则、格里菲斯强度准则以及Hoek-Brown强度准则均为其特例。该准则通过大量的三轴试验引入无量纲强度参数A,n和T,其中A为尺度参数用于控制剪切强度的大小;n为准则曲线的次数用于控制曲率;T为转换参数用于控制准则曲线与σ轴的位置,并反映其无量纲拉伸强度。以Baker非线性强度准则为基础,以极限分析上限法为工具,采用"切线法"思想研究了静、动荷载下边坡的稳定性,将边坡的稳定性问题转化为含多变量的数学优化问题,并给出其最优解。通过算例分析,研究了非线性强度参数对边坡稳定系数与屈服加速度系数的影响。结果表明:边坡稳定系数随无量纲参数A,T的增大而增大;边坡屈服加速度系数随坡高、坡角的增加而降低。

Slope stability analysis based on non-linear failure criterion

The non-linear failure criterion proposed by Baker is a generalized geotechnical strength criterion,and the conventional criterion such as M-C,Griffith and Hoek-Brown strength criteria are all special cases of it.The criterion introduced three non-dimensional parameters A,n,T which can be obtained through triaxial tests,and have clear physical significance.Specifically,A is a scale parameter controlling the magnitude of shear strength,T is a shift parameter controlling the location of the criterion curve and σ-axis and representing a non-dimensional tensile strength,and n controls the curvature of the envelope.Here,based on the Baker criterion,we studied the slope dynamic and static stability using upper bound theorem,transferred the problem to a mathematical optimization problem in a multi-variables expression,and gave the optimal solutions.Then,the influence of the nonlinear strength parameters on slope stability factor and yield acceleration factor are studied through an example.The results show that the slope stability factor increases with the increase of non-dimensional parameters A and T,and the yield acceleration factor decreases with the increase of slope height and slope angle.