边坡渐进破坏的动态强度折减法研究

边破的变形破坏是量变积累到质变的渐进发生过程，由坡体内部潜在滑动面的逐渐破损并扩展至整体滑面。基于强度折减法思想，提出模拟边坡渐进破坏的动态强度折减法。该方法利用屈服接近度指标YAI确定边坡的破损区域，将YAI<0.2的区域定为破损区，通过不断动态折减局部破损坡体的强度参数，使边坡潜在滑动面渐进演化至贯通，边坡达到极限平衡状态。算例计算表明，该方法可有效解决强度折减法中折减范围的问题，克服整体强度折减法破损区过大的缺陷，获得的位移变化趋势与破损区演化过程也具有良好的一致性。动态强度折减法真实再现了边坡渐进失稳过程，为强度折减法更有效地应用于边坡稳定性定量评价提供有效途径。

Research on progressive failure for slope using dynamic strength reduction method

The failure of slope is a progressive process which from quantitative changes to qualitative changes. The whole sliding surface will be taken place by gradual damage of the potential sliding surface in the slope body gradually. Based on the strength reduction method, dynamic strength reduction method that can simulate the progressive failure of slope was proposed. At first, yielding approach index(YAI) is used to appraise the damaged region of slope in the numerical simulation, the region that YAI is less than 0.2 is recognized as the damaged region. Then through the continuous local damage reduction of the strength parameters of the local slope body, the potential sliding surface is damaged gradually and evolved to breakthrough finally. The practical results show that the proposed method can settle the reduction region in the strength reduction method effectively; and overcome the defect of large plastic damage area by the whole strength reduction method. The trend of displacement and damage area change also has better consistency in the reduction process. Dynamic strength reduction method can simulate the progressive failure of the slope truly; and it provides quantitative basis of slope stability appraising for strength reduction method.