Reinforced earth structures situated on soft foundations

Abstract

The authors investigate weaknesses in some current empirical design studies when used with structures situated on poor ground. Although it is theoretically possible to show that conventional earth retaining structures should be better suited to sites with poor bearing pressure capacity than reinforced earth structures, this is not generally the case in practical experience. A series of parametric studies using common material properties and an embankment height of 9 M have been undertaken using the program felsta to illustrate the properties of soft and very soft foundations. The effect of the width of the embankment or reinforced earth structure on overall stability is also investigated. It is concluded that the resistance to movement of the reinforced earth structure produced by the subsoil material radically alters the assumption that the structure will rotate forward about the toe. An expression for the stability of the structure is determined. Empirical design rules are only acceptable for narrow embankments. (TRRL)