Three-dimensional seismic active earth pressure coefficients using upper bound numerical limit analysis

The finite element program Sublim3D, which is a three-dimensional numerical implementation of the limit analysis upper bound theorem, is applied to determine seismic active horizontal earth pressure coefficients, using the equivalent static forces approach to simulate the seismic effect. The calculations are performed for different width/height ratios of the wall, different seismic horizontal coefficients, two representative values of the friction angle and two values of the soil-To-wall friction ratio. The threedimensional influence on the seismic active earth pressures is emphasized. The mechanisms involved in the mobilization of the active earth pressures are inferred from the plastic deformation zones determined by the calculations. The ratios between the threedimensional and two-dimensional seismic horizontal earth pressure coefficients are obtained and found to be, in practical terms, independent on the soil-To-wall friction ratio.