Design of waterfront retaining wall for the passive case under earthquake and tsunami

The paper pertains to a study of analysing a waterfront retaining wall under the combined action of tsunami and earthquake forces. The stability of the waterfront retaining wall is assessed in terms of its sliding and overturning modes of failure. Pseudo-static approach has been used for the calculation of the passive seismic earth pressure. Hydrodynamic pressure generated behind the backfill due to shaking of the wet backfill soil is considered in the analysis. Tsunami force is considered to be an additional force acting on the upstream face of the wall and is calculated using a simple formula. It is observed that the factor of safety in sliding mode of failure decreases by about 70% when the ratio of tsunami water height to initial water height is changed from 0.375 to 1.125. Variations of different parameters involved in the analysis suggest sensitiveness of the factor of safety against both the sliding and overturning modes of failure of the wall and provides a better guideline for design.