Stability of Waterfront Retaining Wall Subjected to Pseudodynamic Earthquake Forces

This technical note pertains to the study of a waterfront retaining wall, retaining a partially submerged backfill, subjected to seismic forces. The pseudodynamic approach, which considers the effect of primary and shear wave propagation in the backfill soil and wall, is adopted for calculation of the seismic earth pressure considering wall inertia. The point of application of the seismic active earth pressure is also affected by seismicity. Hydrodynamic forces are considered in the analysis. It is observed that when the horizontal seismic acceleration coefficient is increased from 0 to 0.3, there is a 65% decrease in the factor of safety of the retaining wall in sliding mode. To investigate the effects of different parameters on design, a parametric study is done. It is observed that with increase in the value of ϕ from 25 to 35° , there is an increase in the factor of safety in the sliding mode by 50%. Comparison with a previous study suggests that the present pseudodynamic approach gives less conservative results than the previous pseudostatic analysis leading to an economic design of waterfront retaining walls.