Methodologies Available for the Determination of Seismic Active Thrust Acting on Retaining Walls: A Critical Review

Design of retaining walls (RWs) in earthquake (EQ)-prone areas requires the knowledge of the distribution of lateral earth pressure behind it. The lateral earth pressure acting on RW in case of dynamic/ seismic loading comprises of two components: (a) earth pressure due to static loading and (b) dynamic incremental pressure due to seismic forces. Pseudo-static and pseudo-dynamic methods are mostly preferred methods used to estimate the seismic earth pressure acting on the RW. Analysis based on pseudo-static approach (PSA) assumes seismic forces as equivalent constant inertial force acting on the wall, whereas pseudo-dynamic approach (PDA) includes the effect of phase change and dynamic amplification of seismic waves. This state-of-the-art paper presents a systematic review on the methodologies available for the determination of seismic active thrust, which are based on PSA and PDA. In addition, several other methods, e.g. methods involving numerical techniques, methods based on arching effect, etc., are also reviewed in this paper. While doing so, various limitations of above-stated approaches are pointed out. Further, it is found that there is scarcity of any rational method for the determination of seismic coefficients used in the analysis based on PSA. In addition, the effect of damping characteristics and excess pore pressure ratio, on seismic active thrust, is attempted in very limited studies.