Pseudo-dynamic approach of seismic design for waterfront reinforced soil-wall

Abstract

Recent failures of waterfront retaining walls under seismic conditions have made the topic important to the researchers to obtain an alternative design solution for those structures. In the present paper, a simple design methodology for waterfront reinforced soil-retaining wall by considering both the hydrodynamic pressure and seismic forces acting simultaneously on the wall has been proposed. The seismic forces are calculated using the pseudo-dynamic approach, which considers the velocities of the shear and primary waves propagating through the soil. Limit equilibrium analysis by considering the horizontal slice method has been adopted. Two types of failure surfaces, viz., linear and polylinear have been used and the results have been reported in terms of normalized value of the geosynthetic reinforcement strength required to counter the hydrostatic pressure, hydrodynamic pressure, and the seismic inertia forces acting on the waterfront wall. Effects of different parameters on this normalized value of the geosynthetic reinforcement strength are also assessed. It was observed that the requirement of geosynthetic reinforcement increases with increase in the horizontal seismic acceleration, vertical seismic acceleration, and the hydrodynamic pressure acting on the waterfront reinforced soil-wall system. Comparing the results of the present methodology with an existing methodology but for the dry backfill case shows that the present results are on the economical side. Merits of the proposed simple design methodology are also highlighted.