Seismic stability analysis of three-dimensional slopesusing elasto-plastic FE method

In engineering practice, the seismic stability for the slopes is usually evaluated by using a pseudo-static (PS) approach or traditional approaches based on the limit equilibrium or on the hypothesis of failure calculation under a two-dimensional condition. Such methods are widely used because of their simplicity and there is no need of complex software for their application. However, they often neglect thethree important elements such as the vertical seismic loading, the three-dimensional scale and the stress-strain relationship of soils, especially the soil deformability and non linear soil behavior. In this paper, the seismic stability for three-dimensional slopes is illustrated using the strength reduction elasto-plastic finite element (FE) method. It will mainly focus on the slope stability and failure mode under vertical seismic loading or the inclined seismic loading using PS approach. Analysis is conducted by numerical modeling using 3D FEprogram. Results are presented in the case of elasto-plastic behavior for soils in order to elucidate the influence of plasticity and seismic loading on the slopes.