PSEUDO-STATIC PASSIVE RESPONSE OF RETAINING WALL SUPPORTING c-Φ BACKFILL

Passive resistance is a significantly important factor for successful design and performance of various structures like anchors, bulkheads, retaining walls etc. Several analytical methods have been introduced time to time to predict the passive resistance for retaining walls supporting soil as the backfill. Most of these methods for the analysis are based on linear failure criterion. Whereas; experimental investigations, theoretical analysis and failed structures have indicated that the rupture surface is supposed to be nonlinear for the most practical environment. Thus, the assumption of planar sliding surface is supposed to underestimate the lateral earth pressure on the active side, which may make retaining walls unsatisfactorily designed at the passive side for support depending on earth pressures. For this reason, the nonlinear analyses were introduced in the earth pressure theories. The methodologies for nonlinear analysis under seismic loading conditions are mostly based on the assumption of log spiral failure surface. Eminent researchers have predicted the failure surface to be a combination of log spiral and straight line. In this paper an effort has been made to derive the analytical expression of passive earth pressure coefficient on the retaining wall from the c-Ф backfill subjected to both horizontal and vertical seismic coefficients. The solution has been carried out by using Horizontal Slices Method (HSM) and limit equilibrium principles to generate a non-linear failure surface. Pseudo-static approach has been used to determine the seismic passive earth pressure. Generalized equation has been developed to find the solution. Results have been prepared in tabular form considering variation of parameters. The results have duly been compared with previous studies to justify the present analysis