Unraveling the Progressive Failure Behaviors and Mechanisms of the Slope with a Local Dynamic Method Based on the Double Strength Reduction

The cohesion c and the internal friction angle phi are mobilized at different reduction proportions and attenuation rates when a slope is in progressive failure, which is a dynamic development process. For this reason, an optimized local dynamic method based on double strength reduction (DSR) is introduced in this paper to capture the double reduction factors and the progressive failure behaviors and mechanisms of the slope. In addition to the DSR technique, the failure approach index (FAI) is also employed to gradually adjust the reduction zone. This optimized method establishes a relationship between the reduction factors of c and tan phi, and reveals the softening mechanisms, sequences, and attenuation rates of c and tan phi. A typical example is modeled to explore the dynamic evolution process of the sliding surface and investigate the progressive failure mechanism. To evaluate the feasibility of the optimized method, some comparisons with common methods are illustrated. A good agreement is found, and the compared results illustrate that this optimized method is helpful for performing a preliminary assessment of slope stability.