Seismic stability chart for 3D Hoek-Brown rock slope: A novel approach integrated tension cutoff and dynamic seismic effect

Abstract

Stability charts are a robust tool for rapidly assessing the stability of slopes in Hoek-Brown (HB) rocks. A notable shortcoming of previous charts has been their limited focus on slip-shear failure induced by equivalent static seismic forces, largely neglecting the potential for tensile failure due to rupture of material, and the dynamic aspects of seismic motion. To enhance the precision of existing chart methodologies, this paper introduces an innovative stability chart for width-restricted HB rock slopes. Seismic safety factors (\({F_s}\)) for constructing the chart are derived through upper bound limit analysis (UBLA). To incorporate the rock's tensile strength, an equivalent linearization of the HB criterion with a tension cutoff is proposed and utilized within an advanced horn-like mechanism. This mechanism features segments that account for tensile and shear forces to facilitate the integration of slope tensile failure. The dynamic seismic influences are captured using a pseudo-dynamic approach, which assumes sinusoidal seismic wave propagation and aids in the incorporation of dynamic seismic parameters such as wave velocity, period, and amplification factor. Utilizing the UBLA-based \({F_s}\), novel charts are developed. Charts incorporating a tension cutoff are enhanced for both intact and jointed rock masses. Two correction factors are introduced to account for the impacts of phase changes and acceleration amplification. Derived from the analysis of extensive datasets, these factors enable the conversion of published chart solutions into more accurate pseudo-dynamic outcomes.