Trial Wedge Approach to Determine Lateral Earth Pressures

Abstract

A method is developed in the paper for the design of retaining walls to calculate three types of lateral earth pressures using the plastic limited equilibrium approach by refining the existing trial wedge method. Use of the developed method makes the calculation of lateral earth pressures contributed by surcharge more logically and cogently consistent with the Rankine and Coulomb theories compared with the current practice of using the combined Rankine and Coulomb method and Boussinesq elastic solution. A specific procedure based on the proposed trial wedge method is developed to more precisely calculate at-rest lateral earth pressure for Coulomb’s retaining wall conditions. The procedure presents advantages over the current practice of using either the Danish Geotechnical Code method or the Army’s strength mobilization factor (SMF) method.