Internal stability analysis of waterfront reinforced soil wall subjected to combined action of earthquake and wave loads

Abstract

Reinforced soil walls situated at waterfront are susceptible to various modes of failure under dynamic conditions. The internal stability of a waterfront reinforced soil wall is a critical aspect of its design and construction. In the present study, internal stability analysis of waterfront reinforced soil wall which is subjected to combined action of earthquake and wave loads has been carried out by considering a log-spiral failure surface. A closed form solution is obtained for the stability of wall using limit equilibrium method (LEM). Internal stability analysis has been performed for soil strata comprising of c-φ partially submerged soil taking horizontal and vertical seismic acceleration (αh and αv) into account following pseudo-static approach. Stability analysis was carried out in terms of a non-dimensional parameter K_Teq which represents total geosynthetic reinforcement force required to sustain the stability. This study considers the effect of different parameters like cohesion (c), pore water pressure ratio (r_u), internal soil friction angle (φ) hydrostatic and hydrodynamic water pressure (P_st and P_dyn) due to wave loading on stability of wall. It is observed that, due to the increment in the horizontal seismic acceleration coefficient (k_h), vertical seismic acceleration coefficient (k_v,) and hydrodynamic pressure, the requirement of geosynthetic reinforcement also increases and the presence of water significantly affects the strength of the reinforcement and an increase in the ratio of wave height to the depth of water at the seaward side increases the requirement of reinforcement. Also, it is found that the present study has good agreement with the previous studies conducted.