Dynamic response and permanent displacement of high-steep slopes under near- and far-field earthquakes

Based on the two-dimensional finite element simulation model of rock slope interbedded by hard and soft layers, the dynamic responses of the slope under near-field and far-field earthquakes are studied. The dynamic responses (dynamic amplification factor, the maximum shear stress and the maximum principal stress) under far-field earthquakes are greater than those under near-field earthquakes. The safety factors of the slope calculated by means of the time history method and the pseudo-static method of Chinese standards are compared, and the pseudo-static method has shortcomings in seismic dynamic stability evaluation. The critical acceleration calculated by the elastic-plastic finite element numerical simulation is substituted in Newmark's sliding block formula, and the permanent displacements of the slope considering the effect of near-field and far-field earthquakes are calculated. The results calculated by use of the Newmark's method are lower. The permanent displacements under far-field earthquakes increase by 26% (Newmark's method) and 29% (elastic-plastic finite element method) compared with those under near field earthquakes. Finally, the stability of slope is evaluated based on the permanent displacements proposed by Jibson and Michae, and the permanent displacement of 1 cm as the critical evaluation value of slope from mild damage to moderate damage is more reasonable.