Analytical expression for dynamic passive pressure from c-ϕ soil backfill with surcharge

Abstract

The dynamic passive earth pressure as a resistance to the retaining wall movement is often required for the design of retaining walls, whose lower parts are embedded in the ground. This technical note presents the derivation of an analytical expression for the total passive earth pressure on a retaining wall from the c-ϕ soil backfill subjected to surcharge and seismic loads. The developed expression has been analysed for some special cases, and they have been found identical to those proposed by earlier researchers on the subject. The graphical presentations show that the total dynamic passive force increases but the critical inclination of the failure plane within the soil backfill to the horizontal decreases with an increase in the surcharge pressure. When compared to situations without seismic loading, the effect of seismic loading reduces the inclination of the failure plane to horizontal slightly. The presence of surcharge reduces this even further. The design value of total dynamic passive force should be obtained with consideration of vertically upward seismic inertial force along with the horizontal seismic inertial force towards the soil backfill.