Verification of Rankine Earth Pressure Theory Using Finite Element Analysis with Elastic-Plastic Material

Abstract

To simulate the Rankine earth pressure theory in the finite element analysis, a frictionless rigid wall and backfill system supported by rollers can be used. Beginning from the initial at-rest pressure conditions, the wall is moved towards or away from the backfill in a series of increments, until the passive or active earth pressure condition is reached. To obtain numerical solutions, twenty-five finite isoparametric elements are used to simulate the backfill and six linear bar elements to represent the rigid retaining wall. In order to simulate the incremental displacements, bar elements with a very high stiffness are used. The effect of wall displacement can be accomplished by applying a load equal to the value of the bar stiffness times the displacement to the nodal points that connect bars and soil elements. The elastic-plastic Drucker-Prager soil model is used in this study. Two earth pressure study cases have been analyzed. The first case deals with a cohesionless soil, while the second one a cohesive soil. The obtained load-displacement curves and stress-displacement curves are presented. It is found that the earth pressures behind the retaining wall at different heights based on the numerical solutions are identical with the calculations obtained from the Rankine earth pressure theory.