Seismic response of retaining walls: Theoretical parametric insights after centrifuge validation

To gain insight into the dynamics of retaining systems, the seismic response of a "non -displacing" U-shaped and a "displacing" cantilever retaining wall in dry sand stratum is studied by numerical analyses using a refined constitutive model, with the wall-soil interface allowing separation and sliding. The results were motivated from, and are successfully compared with, a series of comprehensive centrifuge experiments by Sitar and co-workers. Tests and analyses use as base excitation three accelerograms from Kobe, Kocaeli and Loma Prieta. Results are presented in terms of acceleration time -histories, response spectra, plastic strain contours, and lateral soil pressures. Emphasis is given to numerically-obtained soil lateral pressures, and the parametric study shows that while such pressures are difficult to accurately predict, they may nevertheless be in (barely satisfactory) agreement in shape and even often in magnitude with either: (i) Mononobe-Okabe-type, or (ii) the Veletsos and Younan (1994) [39] analytical solutions, depending on the displacement constraints of the wall, the rotational flexibility at the base, and the severity of the excitation.