Displacement-controlled analysis of embedded cantilever retaining walls.

Abstract

An uneconomical design of embedded cantilever retaining (ECR) walls unnecessarily restricts the lateral wall movement, whereas unwarranted wall displacement induced ground settlement can jeopardize the functionality of neighboring structures. Thus, correct estimation of the wall displacement under working conditions is imperative for a safe and economical design. This paper presents an analytical method for the displacement-controlled analysis of ECR walls in cohesionless soils, which can be used to calculate the required embedment depth for a prescribed wall displacement and retaining heights. Alternatively, when the retaining height and the embedment depth of an ECR wall are given, the lateral wall displacement can also be calculated. A displacement-dependent earth pressure mobilization model is proposed to derive the mobilized soil stresses along the wall height. The required embedment depth of the wall is determined by assuming rigid rotation of the wall about a point near the toe and satisfying the horizontal force and moment equilibriums. Analytical formulations are provided to determine the bending moment distribution and the ground settlement. The effect of construction by excavation is also taken into the analysis. The results show that the required embedment depth and the maximum bending moment increase exponentially with decreasing wall displacement. The depth of the pivot point is located at around 0.9 times the embedment depth. The validity of the proposed method is demonstrated by comparing the calculated results with those of the available numerical and experimental studies. The proposed method can provide first-hand design solutions of ECR walls without performing rigorous numerical and experimental studies.