Modeling of rapid evaluation for seismic stability of soil slope by finite element limit analysis

Abstract The rapid evaluation of post-earthquake landslides and unstable slopes (whether they will be revived by aftershocks) is a key task in the post-earthquake emergency response phase. Stability chart and Newmark model is generally used for rapid evaluation of seismic stability of soil slopes. In this study, a novel method for directly estimating static, pseudo-static safety factors and critical accelerations of soil slopes is proposed; this method overcomes the limitations of stability chart and Newmark model. Based on finite element limit analysis and Mohr-Coulomb criterion, safety factors and critical acceleration of typical slope models are studied via the parametric method. First, a stability chart of safety factors under static and pseudo-static states is calculated by finite element limit analysis. Correspondingly, the critical acceleration under static condition is obtained. Next, the seismic weighting factor and slope angle weighting factor are put forward, and a rapid evaluation model of safety factors is established. Finally, according to the correlation between safety factors and critical acceleration under static conditions, a rapid evaluation model for critical acceleration is proposed. The proposed method is compared with the results of the Newmark model and finite element limit analysis. The results show that the prediction accuracy of the proposed method is closer to the results of finite element limit analysis than those of Newmark model. The proposed seismic stability model is reliable and efficient and can be used to evaluate the stability of soil slope at the initial design stage and provide reference for further seismic design.