基于动态和整体强度折减法的边坡稳定性分析

 基于强度折减法的边坡稳定性评价只能获得静态单一的安全系数。为获得边坡渐进失稳过程中的稳定性状况，提出基于动态和整体强度折减法的边坡动态稳定性评价方法，利用动态强度折减法搜索出渐进扩展的滑动面，并结合整体强度折减法计算安全系数的优势，在边坡渐进失稳过程中计算动态安全系数，从而实现对边坡失稳全过程的分析和调控。首先，利用动态强度折减法确定出一系列扩展的滑动面，然后，在每一步折减中降低滑动面的强度参数，随后采用整体强度折减法计算此刻的安全系数。最后进行滑动面扩展–安全系数的对应分析，根据安全系数的动态变化规律对边坡进行稳定性评价和支护。两实例计算表明，动态强度折减法获得的滑动面与实际监测数据相吻合，合理反映边坡(滑坡)的变形破坏特征。利用动态和整体强度折减法的各自优势，获得边坡渐进失稳过程中的一系列动态安全系数，更利于边坡的稳定性判断及支护措施建议。相比于极限平衡法，动态强度折减法也更适合于非均质边坡的稳定性评价，能搜索出正确的潜在滑动面。

STABILITY ANALYSIS OF SLOPE BASED ON DYNAMIC AND WHOLE STRENGTH REDUCTION METHODS

Slope stability evaluation based on strength reduction can only obtain static single safety factor. The dynamic evaluation method of slope stability is proposed based on dynamic and whole strength reduction methods in order to obtain the slope stability in the progressive failure process. At first，a series of expanded sliding surfaces are searched by using the dynamic strength reduction method(DSRM)；and then the strength parameters of the sliding surface are reduced in each reduction step. The corresponding safety factor of the slope is calculated by using whole strength reduction calculation. At last，the relationship of sliding surface propagation and the related safety factor is analyzed. Therefore，slope stability evaluation and support suggestion can be given according to the change rule of dynamic safety factors of slope. Two case studies show that sliding surface obtained by DSRM is consistent with in-situ monitoring data，reasonably reflecting the failure characteristics of slope or landslide. A series of dynamic safety factors are presented in the progressive failure process by using the advantages of DSRM and whole strength reduction method respectively. The DSRM benefits stability judgment and supporting measures suggestion of slope. Compared with the limit equilibrium method，the DSRM is more suitable for stability evaluation of the heterogeneous slopes；and it can search the potential sliding surface accurately.