Seismic active earth pressure on retaining wall with two-layer of cohesive backfill

An advanced computation approach was presented to study the seismic active earth pressure on retaining wall with two-layer cohesive backfill. Based on the assumption of Mononobe-Okabe theory, the expression for the total seismic active earth pressure was derived. The cohesion force on the sliding plane and the adhesive force on the interface of backfill and retaining wall were considered in the analysis. The developed formula can be degenerated to Mononobe-Okabe earth pressure expression for the case of homogeneous cohesiveless soil backfill. The parametric study shows that the seismic active earth pressure increases with the increase of horizontal seismic acceleration coefficient, while it decreases with the increase of vertical seismic acceleration coefficient. Both horizontal and vertical seismic inertia forces have significant effect on the value of seismic active force. Compared with the results of other methods for calculating the seismic earth pressure, the value of seismic active force obtained from the present study is lower than that of the layer method for the same parameters.