Active Earth Pressure against Cantilever Retaining Walls with the Long Relief Shelf Rotating about the Bottom

Abstract

A cantilever retaining wall incorporating a long relief shelf is a specific form of retaining wall. However, currently, there are no reports investigating this retaining wall rotating about the bottom. Herein, the failure mode of semi-infinite noncohesive soils is studied using the finite-element limit analysis method (FELA) when the wall rotates about the bottom. The results show that the backfilled soil initiates the development of first and second failure surfaces at the end of the wall heel, and the third failure surface propagates at the shelf’s end. In the failing soil, there are numerous subfailure surfaces parallel to the first, second, and third failure surfaces. By considering both the effect of the relief shelf and the equilibrium limit analysis of the differential soil slice, this study derived a formula for calculating the active earth pressure of cantilever retaining walls with the long relief shelf. The effect of three different parameters, i.e., relief shelf length and location, and wall heel length, on the distribution of active earth pressure, the total active earth pressure, and its application point was studied. The longer the relief shelf and the shorter the wall heel, the lesser the active earth pressure. Consequently, when the relief shelf is set at the height of 0.3 times the wall height from the top of the wall, the active earth pressure is the smallest.