Influence of Bedrock Inclination on Seismic Slope Stability Based on Seismic Data of Iran

In this paper, the effect of bedrock inclination on seismic performance of slopes is investigated. The study was conducted based on dynamic analysis of different slopes, evaluation of the earthquake acceleration in sliding mass, and calculating the permanent displacement of the slope, using Newmark sliding block. The investigation indicates that variation of the bedrock inclination, which results in a change in the predominant period of the slope (Ts), in conditions that the mean period of the time history of the acceleration on critical sliding surface (Tmt) and Ts are close to each other, causes the variation of the acceleration magnitude and the Newmark displacement in the sliding mass and they may reach to their maximum level. Typical results are presented and discussed. A two dimensional model of a typical slope was considered and conducting dynamic analyses, the slope performance was studied for different geometries, strength parameters and shear wave velocities. Such a performance has been studied by assessing the record of acceleration in sliding mass (the mass above the critical sliding surface) and calculating the slope displacement using Newmark method. It is shown that neglecting the effect of bedrock inclination, would lead to non-real results in assessing the seismic slope performance.