Seismic Displacement of 3D Slope Reinforced by Piles with Nonlinear Failure Criterion

The seismic displacement estimation of soil slopes was generally focused on the plane strain assumption with a linear Mohr-Coulomb failure criterion. In engineering, slope stability often becomes more of a three-dimensional (3D) issue when the reinforcement effect of antislide piles is considered. In this study, an approach was proposed for seismic displacement prediction of 3D slopes reinforced by piles with nonlinear failure criterion based on the upper bound theorem of limit analysis. To depict practical strength characteristics of soil mass, the nonlinear failure criterion was introduced by means of the generalized tangent technique. The formula for resistant force acting on piles was derived in the light of plastic mechanics. The rates of external work and internal energy dissipation were deduced, in which variation of the reinforcement effect of piles along the sliding surface was considered. The analytical expression for yield acceleration coefficient was presented, and the seismic displacement was then calculated based on the Newmark method. Compared with existing research, the validity of obtained solutions was shown. Some examples were then discussed, with the soils following different failure criteria. It was found that stability assessment of slopes on the basis of a nonlinear failure criterion is more critical in the most cases. Parametric analysis was conducted and the yield acceleration was found to be more sensitive to the initial cohesion.