Estimating sliding displacement of slopes induced by earthquake sequences based on the finite element method

Abstract

Abstract After shocks trigger or worsen landslides by exacerbating damage to slopes. In this study, slope sliding displacements induced by seismic sequences were calculated. The combined effects of mainshocks and aftershocks on slope sliding were examined in this study using 273 ground motion records from real seismic sequences. A three-layer clayey slope was modeled in OpenSees. The ground motions were input for dynamic analysis to calculate the corresponding sliding displacements. More than 20% of the seismic sequences caused slope instability. The Arias intensity (Ia) of the mainshock had the strongest correlation with sliding displacements. The strength reduction technique was used for the pseudo-static stability analysis of the slope whose yield acceleration (ky ) value was 0.23g. The Newmark method computed smaller displacements compared to the finite element method which calculated the dynamic behavior of the slope more accurately when Ts/Tm > 0.1. The Ia of the mainshock was the optimal parameter. An empirical model based on finite element numerical analysis was proposed for predicting slope sliding displacements induced by seismic sequences. The predictive model, unlike the traditional rigid sliding block method, prevented some unrealistic assumptions. The proposed model was more conservative than numerical algorithm-based predictive models that compute only the mainshock effect.