Investigation on Seismic Slope Stability Based on Pseudo-static Analysis.

Abstract

This study presents a numerical procedure by means of shakedown analysis to assess the seismic stability of slope based on the pseudo-static concept. The factor of safety was defined with the strength reduction coefficient as commonly employed in slope stability. The applicability of the numerical procedure was examined firstly to the static slope stability assessment through the comparison in factor of safety with the Taylor's friction circle method. It was clearly shown that the factors of safety of two methods were in good agreement and the proposed method assessed the static slope stability properly. Secondly, the seismic stability of slope was investigated in the frame of pseudo-static concept. The effect of earthquake load direction on the seismic stability was widely investigated for cohesive and frictional soils. The factor of safety obtained for the horizontal seismic coefficient was found to be close to the critical factor of safety in direction. Thirdly, the effect of repeated change in both direction and magnitude of earthquake load on the factor of safety was especially examined. It was found that the repeated change in earthquake load affected the seismic slope stability significantly, especially in the case of frictional soil. However, it was found that the factor of safety for the horizontal alternating load was close to that for the alternating load in every direction in the same way with the monotonic earthquake load.