Seismic Stability of a Broken-Back Retaining Wall Using Adaptive Collapse Mechanism

Abstract

In this study, the pertinence of a broken-back retaining wall with bilinear backface in mitigating the effect of earthquake is demonstrated using the method of stress characteristics coupled with the pseudodynamic approach. Unlike the available studies reported in the literature considering the limit equilibrium or the limit analysis method, a priori failure mechanism is not assumed in this analysis, and the failure mechanism automatically gets evolved from the solution of stress characteristic equations. The versatility of the solution procedure is explored with the available seismic methods such as pseudostatic, original pseudodynamic, and modified pseudodynamic approaches. The effect of various parameters such as inclination and roughness of the wall, angle of internal friction of the backfill soil, damping of the soil, and phase difference of seismic waves on the active thrust is determined in the analysis. The stability analysis of the wall is performed using the classical Newmark's sliding block approach. The present results are compared with the available data reported in the literature. The seismic stability factors are found to be critical while considering the dynamic properties of the soil and the wall. The efficacy of employing the broken-back geometry over the conventional vertical retaining wall is presented for different wall configurations.