Lateral Wall Deflections of Braced Excavations in Clay

Abstract

The lateral deflections of sheetpile or diaphragm walls are often used to evaluate the performance of braced excavations. This paper examines the influence of a number of factors affecting the lateral deflections of strutted or anchored sheet‐pile walls in clay using the finite element method, such as the undrained shear strength, the width and depth of excavation, the wall stiffness, the penetration depth, and the depth to hard stratum beneath the bottom of the excavation. A simple procedure to estimate the lateral deflection is proposed. It has been assumed that the walls are flexible and the lateral deflections are governed by the plastic yielding of the soil below the bottom of excavation. The yielding is inversely proportional to the factor of safety with respect to basal heave. A nonlinear hyperbolic stress‐strain relationship has been used in the analysis. Deflections computed by this method compare favorably with field records and published results.