A Generalized Framework to Estimate the Seismic Active Thrust on Rigid Retaining Walls with Partially Saturated Backfill

This paper proposes a generalized framework to estimate the seismic active earth thrust on rigid retaining walls with unsaturated backfill. A novel suction stress-dependent approach was developed to compute the horizontal and vertical seismic acceleration profiles within the backfill. The framework applies the limit equilibrium method with a log-spiral failure surface and considers the influence of suction-stress through the effective stress approach. A detailed validation of the proposed framework is conducted by comparing it with well-established solutions reported in previous studies showing a satisfactory agreement. Validation was performed for the cases of static loading with suction and seismic loading without suction because of the unavailability of the data for the combined case. The influence of suction on the seismic active earth thrust for different soil types and environmental conditions is presented together with other parameters including wall height, soil friction angle, frequency of input excitation, and horizontal and vertical seismic acceleration coefficients.