基于SLFT边坡双折减系数强度失稳判据

基于滑移线场理论（SLFT），提出了一种边坡双折减系数强度折减法失稳判据:当由滑移线场理论计算得到的极限状态下的边坡坡面（简称"极限稳定坡面"）与原坡面相交于坡脚时，判断边坡处于极限状态。基于提出的失稳判据构建了双折减系数倒数空间的临界曲线，并推导了整体安全系数计算公式。边坡算例计算结果表明:初始点和临界曲线的3种相对位置关系（点在曲线上方，点属于曲线，点在曲线下方）对应3类边坡整体安全系数（FS>1，FS=1，FS<1），整体安全系数计算结果与边坡状态相符合，确定的临界滑裂面形状以及在边坡中的位置都与已有结论一致。提出的失稳判据适用于计算配套系数和整体安全系数，实现了失稳判据的客观标准定量化。 

A new instability criterion of double strength reduction method for slope

Based on the slip line field theory(SLFT), a new instability criterion of strength reduction method with double re-duction factors for homogeneous slopes was proposed. It is judged that the slope is in the limit equilibrium state when the slope contour under limit equilibrium state(abbreviated as the critical slope contour) calculated by the SLFT intersects with the slope line at the toe. The critical curve was constructed in the plane of the inverse of the double reduction factors, and the comprehensive safety factor was derived. The slope calculation results show that three relative position relationships between the initial point and the critical curve, i.e., the point is above, on, or below the critical curve corresponding to three types of safety factors, i.e., FS>1, FS=1 or FS<1. The proposed instability criterion is suitable for calculation of the reduction proportionality factor and the comprehensive safety factor, and realizes the objective quantification of the instability criterion.