Effect of flexural stiffness on static and dynamic behavior of cantilever retaining walls

A series of centrifuge tests was conducted to simulate static and dynamic behavior of fixed-base, cantilever retaining walls supporting saturated, liquefiable backfill. Effect of wall stiffness was studied by conducting tests on three model walls of same height with different flexural stiffnesses. Accelerations of the walls and in the soil, static and dynamic pore pressures in the soil, wall deflections, bending strains, and lateral earth pressures on the walls were measured in the tests. The effect of wall stiffness on these quantities and on the wall-soil system was investigated. It was found that flexural stiffness of fixed-base, cantilever retaining walls does not have significant effects on the static lateral pressures from saturated soil. Static lateral earth pressures can be estimated according to Coulomb's theory. Static bending strains and deflection of the wall can be estimated according to the beam theory. During earthquakes, higher than expected defections and strains can be generated in flexible cantilever walls. It was also found that irrespective of the wall stiffness, the residual lateral thrust on the wall at the end of the earthquake would be the same as long as the soil backfill liquefies completely.