Immediate Estimation of Yield Acceleration for Shallow and Deep Failures in Slope-Stability Analyses

Abstract

The accurate assessment of the stability of natural slopes and earth structures during earthquakes is a critical design aspect for seismically active areas. The Newmark-type displacement method, which is capable of estimating permanent earthquake-induced displacements, is extensively adopted to evaluate slope stability under seismic loading. However, this approach becomes unmanageable for regional assessment because hundreds or thousands of iterations are required to obtain the yield acceleration (ky), which is estimated by trial and error in conventional slope-stability analyses. To reduce computational effort, a simple procedure is developed for the noniterative evaluation of ky for both shallow and deep slope failures. The factor of safety (FS) of slopes under static conditions is first calculated based on developed stability charts. Thereafter, ky is determined through its established correlation with FS. The ky calculated using the proposed procedure corresponds well with that obtained using the trial-and-error approach (5% difference). Thus, the proposed procedure can be applied efficiently in a regional assessment with thousands of slopes.