Seismic active earth pressure of unsaturated soils with a crack using pseudo-dynamic approach

Abstract

Abstract The analyses of active earth pressure subjected to earthquake shaking are routinely explored concerning dry or saturated soils. However, the fact often neglected in previous literature is that soils are mostly unsaturated in nature. This work puts forward a kinematical approach for the assessment of active resistance of a rigid retaining structure against unsaturated backfills with pseudo-dynamic approach, and the effect of a crack presented in backfills is also considered. A layer-wise summation method is employed to compute the non-uniformly distributed seismic forces due to earthquake accelerations considering time and spatial effects and corresponding work rates. Several nonlinear formulae as well as different soil-water characteristic curve models are employed to determine the additional cohesion caused by matric suction. To verify the validity of the proposed approach, a comparison is conducted with its simplified modality and conventional pseudo-static approach based on identical input conditions. The comparison results show good agreement. The lateral earth pressure can be derived from the principle of work rate balance using a numerical optimization technique. A parametric analysis is implemented to investigate the influences of crack depth, water level, dynamic factors of seismic effects and nonlinear evaluation models on the critical seismic active earth pressure.