STUDY OF RUPTURE SURFACE DUE TO SURCHARGE ON THE COHESIONLESS BACKFILL OF RETAINING WALLS

Abstract

Model tests were performed to study the rupture surface and pressure distribution behind a retaining wall with surcharge on the backfill. The study was made for all the three type of wall movements i.e. translation, rotation about the bottom and about the top, both for active and passive conditions. The tests were conducted in a tank of size 150 x 65 x 61 cm having a wall of mild stee1,49.5 cm high. The wall could be given desired type of movement and displacement by means of a heavy driving screw. Deforming diaphragm type pressure cells were used to measure the earth pressure. The results were compared with some of the existing theories and it was noted from the tests that the effect of surcharge is to -_-,educe the size of failure wedge under active conditions and to increase the size of failure wedge under passive conditions. Dense sand gave smaller failure wedge under active conditions and larger failure wedge under passive conditions. It was also noted that the effect of surcharge is to reduce the coefficient of passive earth pressure under all conditions of tests.