DYNAMIC LATERAL EARTH PRESSURES ON BASEMENT WALLS INDUCED BY HARMONIC GROUND MOTIONS

In recent years, a number of publications on dynamic lateral earth pressures acting on basement walls induced by seismic ground motions has appeared due to good performance of basement walls during relatively large earthquakes. The main concern is whether the current methods would provide excessively conservative lateral earth pressures. In this paper, the 2-D plane strain dynamic finite element models were used to examine the lateral earth pressures acting on 2-story concrete basement walls. The seismic ground motions were constant-peak, harmonic ground motions; three different peak acceleration values were considered. The Mohr-Coulomb constitutive soil model was used in the analyses to represent a sands deposit. The observed parameters were the horizontal wall acceleration, the lateral earth pressures and their changes, and the lateral total thrusts (PAE). The overall results showed the complex nature of the dynamic soil-structure interaction of basement structures. Some of the findings include the effect of limiting soil tensile strength on the envelope of change in lateral earth pressures (∆pAE), the non-linear increase in and complex distribution of ∆pAE with an increase in the peak input acceleration, highly non-linear relationship between PAE and wall acceleration, a discussion on phase difference, and the effect of the embedment wall depths.