滑坡稳定性分析的点安全系数法

建立滑坡数值计算的三维模型，将滑带离散为薄层8节点六面体单元，采用基于摩尔-库仑强度准则的理想弹塑性本构模型模拟滑带材料，通过数值计算，可获得滑带单元的三维应力状态和滑动方向。定义单元点安全系数为滑带单元抗剪强度与滑面上平行滑动方向的剪应力之比，定义滑坡整体安全系数为单元点安全系数对滑带面积的加权平均值。采用点安全系数分析滑坡的空间滑动机制，采用整体安全系数评价滑坡稳定性。算例分析表明，分析结果符合现场实际情况。

Point safety factor method for stability analysis of landslide

A 3-D model for numerical calculation of landslide is proposed; and a high-precision eight-node hexahedron element is used to build the finite element grid of slip layer. The slip layer material is simulated by an ideal elastoplastic model based on the Mohr-Coulomb criterion. Three-dimensional stress state and slide direction of the slip layer zone are obtained by numerical computation. So based on the analysis of the three-dimensional stress state of the slip layer zone, a point safety factor as the ratio of the shear strength of the slip zone to the shear stress parallel to the gliding direction is defined; and the safety factor of the landslide as the weighted average value of the zone point safety factor with its zone is defined. The sliding mechanism is studied through zone point safety factor; and landslide stability can be evaluated through the safety factor. The case studies show that the calculated results are consistent with the actual cases.