Estimation of the seismic earth pressure is an important topic of research for the safe design of retaining wall in the seismic zone.But under seismic condition

the available solution mostly give the pseudo-static analytical value of the earth pressures as an approximate solution to the real dynamic nature of the complex problem.A recently developed pseudo-dynamic method

which incorporates time dependent effect of applied earthquake load and effect of shear and primary waves

is applied to study the seismic passive earth pressure behind a vertical retaining wall.A planar failure surface has been considered behind the retaining wall

the effects of horizontal and vertical earthquake accelerations

shear wave velocity

primary wave velocity

wall friction angle

soil friction angle

the ground slope of backfill on the seismic passive earth pressures has been explored.Unlike the Mononobe-Okabe method

which is pseudo-static analysis

the present analysis predicts a nonlinear variation of passive earth pressure along the wall

which is more realistic under earthquake condition.