Limit state line-based seismic stability charts for homogeneous earth slopes

Abstract

The stability charts for static and pseudo-static (PS) stability analysis of homogenous slopes have been widely used for preliminary design work. Based on the concept of a graphical stability chart, where the factor of safety (FoS) is simply a ratio between two lines, this study presents a series of improved stability charts based on limit equilibrium PS analysis of a wide range of homogeneous slope models with inclination angles varying from 10° to 60°, and considering both horizontal and vertical seismic loads. The limit state lines (LSL) are presented, and their mathematical expressions are obtained from extensive regression analyses. The LSL-based graphical stability charts’ solutions are proposed for PS stability analysis of homogeneous slopes with any given combinations of physical parameters. The proposed charts show very good performance for rapidly obtaining the PS FoSs; the calculation errors are generally within 10%. In addition, the developed charts can intuitively reflect the possible slope failure modes and their state transformation with the variations of soil strength, slope inclination and seismic coefficient. Thus, the proposed chart solutions may serve as a promising tool for practising engineers to estimate the FoS of homogenous slopes considering seismic loading effects.