Seismic active earth resistance of submerged backfill considering anisotropic seepage

Abstract

Based on limit equilibrium analysis, this paper presents a general pseudo-dynamic solution for the seismic active earth pressure considering anisotropic seepage conditions. The proposed method is applied to a vertical waterfront wall retaining fully submerged backfill with a drainage system along the soil-structure interface. To simplify the calculation, a steady state hydraulic head field satisfying Darcy’s law in the backfill and a two-dimensional seepage distribution with anisotropic permeability is assumed. And the anisotropic coefficient is introduced to evaluate the anisotropic seepage differences in the vertical and horizontal directions. Then the analytical derivation includes the pore pressures induced by the anisotropic seepage, the excess pore pressures triggered by earthquake actions and the seismic inertial forces obtained by the pseudo-dynamic method. To reveal the mechanism of seismic active earth pressure, the influences of seismic load characteristics, friction angles, and anisotropic seepage conditions on the total active earth pressure are investigated by parametric studies. The results indicate that the presence of anisotropic seepage leads to a decrease of the seismic active earth pressure. Finally, the calculations of the present solution are compared with the findings of previous research to verify the rationality of the proposed method. This method makes some contributions to improve the calculation for the seismic design of waterfront retaining walls.