A typical geogrid reinforced soil retaining wall constructed with and without facing units was analyzed for seismic response. The walls are proportioned using the Pseudo-Static design method. A finite element method―ABAQUS-code―was employed using Drucker-Prager model to characterize sand and nonlinear elastic reinforcement material. This paper presents the wall responses to a typical seismic spectrum. Of particular interest in this study are: (1) the acceleration response, (2) the wall displacement, (3) the tensile stress in the reinforcement, and (4) the slippage at the soil-reinforcement interface. Probable failure modes were also sought in this study. Specifically, three possible failure mechanisms were investigated, namely, wall displacement, tensile stress in reinforcement, and slippage between soil and reinforcement. Having designed for peak acceleration of 0.25g in conjunction with a factor of safety of two, the walls withstood a base excitation of 0.5g ground motion. While imposing surcharge loads of different magnitudes, however, those responses begin to accumulate over the duration of the simulated seismic event, indicating imminent failure in one mode or another. Slippage at the interface seems to the probable failure mode of the wall without facing whereas the wall with facing would fail by breakage of the reinforcement.
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