Slope Stability Analysis Considering Different Contributions of Shear Strength Parameters

摘要

From the perspective of the mechanical mechanism of slope failure, cohesion c usually plays a different role with friction phi in sliding resistance, which indicates the distinct weights of their reduction factors Fs(c) and Fs(phi) to the overall safety factor of slope Fs in the double strength reduction method (DSRM). This study primarily introduced the equivalent influence angle of slope theta(e), for which c and phi share identical contributions to the safety factor, and investigated its influencing factors, which turns out that theta(e) shows an increasing trend with an increase of slope weight H or slope height gamma, but the increasing rate is decreasing. Subsequently, an equivalent influence angle chart was plotted as an effective and advantageous approach to locate the specific value of theta(e) for a given slope. On this basis, the shortest reduction path method was utilized to calculate Fs(c) and Fs(phi), and the stability contributions of c and phi were quantified by the different weight coefficients of Fs(c) and Fs(phi) to Fs. The specific weight coefficient could be solved by the correlation between slope angle theta and corresponding theta(e), thereby developing a new definition of Fs. Ultimately, a modified double strength reduction method was achieved, which was compared with other DSRMs and verified by existing slope examples. (c) 2020 American Society of Civil Engineers.