Seismic ground motion induced lateral earth pressures on basement walls

Research on the dynamic lateral earth pressures acting on basement walls induced by seismic ground motions has appeared in the literature in the last few years to examine the apparent inconsistency between the theoretical pressures and the pressures suggested by basement wall good performance of during large earthquakes. This inconsistency suggested that the current methods would yield excessive lateral earth pressures. In this paper, a two dimensional plane strain finite element model of a 2-story concrete basement wall was used to examine the dynamic lateral earth pressures. The seismic ground motion was the N-S component of the 1992 Erzincan earthquake motion record. The assumed soil profile was a sands deposit overlying a reflecting bedrock layer. The observed time history outputs were the wall acceleration in horizontal direction, the lateral earth pressures, and the associated lateral thrust. The outputs were examined further to evaluate the amplification of wall acceleration, the different time history pattern of wall acceleration and lateral thrust, the influence of limiting soil tensile strength, the time difference for peak wall acceleration and peak lateral thrust, and a discussion on phase difference. The results suggested that the complex interaction could not be represented by typical simple peak input acceleration - soil pressure relationships.