A Simplified Method for Effective Calculation of 3D Slope Reliability

Abstract

Traditional 3D slope reliability analysis methods have high computational costs and are difficult to popularize in engineering practice. Under the framework of the limit equilibrium method with 3D slip surface normal stress correction, the critical horizontal acceleration coefficient Kc, which is equivalent to the safety factor Fs, is selected to characterize the slope stability. The limit state function uses the difference between Kc and the known critical value Kc0. A simplified method for calculating the reliability of 3D slope is proposed. Through two typical slope examples, the 3D reliability calculation results of six methods after coupling two limit state functions and three reliability algorithms are compared. The results show that this method is reliable and effective, and the method coupled with subset simulation (SS) is the one with good calculation accuracy and efficiency. In the case of long slopes, 2D analysis results may underestimate the probability of slope instability, and 3D reliability of the slope must be analyzed.

Keywords

• 3D slope reliability
• limit equilibrium method
• slip surface normal stress correction
• critical horizontal acceleration coefficient
• limit state function