Pseudodynamic Analysis of a Bilinear Waterfront Retaining Wall under Earthquakes and Tsunamis

Abstract

The stability of the waterfront retaining walls is critical while subjected to the combined actions of a tsunami and earthquake. Although rare, simultaneous occurrences remain critical for prominent structures. However, the design criteria for this coupled action are available only for waterfront retaining walls with a vertical or inclined backface. The current study presents the seismic design and stability analysis of a waterfront retaining wall with a commonly used bilinear backface subjected to tsunamis and earthquakes by employing a limit equilibrium approach coupled with a pseudodynamic method for a passive state. The factor of safety reduces by 83%–99% for sliding and overturning when waterfront retaining walls are subjected to the combined forces of an earthquake and tsunami rather than an earthquake alone. Suitable design charts with factors of safety for sliding and overturning are presented for various parameters such as tsunami wave height, depth of water at the seaward side, height of submergence, excess pore pressure ratio, and wall inclination, which certainly facilitates the optimum construction of a waterfront retaining wall with a bilinear backface.