Finite element analysis of the effect of corrosion on the behavior of reinforced earth walls Truong-Linh Chau 1 , Emmanuel Bourgeois 2, * and Alain Corfdir 1 1 Université Paris-Est, UR Navier, Ecole des Ponts ParisTech, 6–8 av B. Pascal, 77455 Marne-la-Vallée Cedex 2, France 2 Université Paris-Est, IFSTTAR-MACS, 58 bd Lefebvre, 75732 Paris Cedex 15, France ABSTRACT A simple model for the corrosion-induced loss of stiffness and strength of the steel strips of earth-reinforced walls was introduced in a finite element simulation of the long-term behavior of the wall, in which the back- fill-strips interactions are taken into account by means of a generalized homogenization procedure (called a multiphase model). The results show an initial phase of slow displacements induced by the loss of stiffness, followed after a few decades by a steep acceleration of the displacements, leading to wall failure. The influ- ences of the parameter controlling corrosion, the backfill cohesion and the heterogeneity of the corrosion process are discussed. Results are used to discuss a strategy for reinforced earth wall surveillance. Copyright © 2011 John Wiley & Sons, Ltd. Received 8 February 2011; Revised 30 June 2011; Accepted 18 July 2011 KEY WORDS: homogenization; reinforced earth wall; corrosion; finite element analysis 1. INTRODUCTION Reinforced earth walls are an economical solution to building retaining structures for transportation infrastructures and other types of facilities and can be useful in difficult design conditions, notably when available space is restricted. The technique consists of reinforcing a backfill material with steel strips, whose tensile strength is used to ensure the internal stability of the wall. The service life of reinforced earth walls used for transport infrastructures is the period of time during which the wall must remain in an allowable stress state. For transportation structures, the typical value of the service life is taken to be equal to 75 years in France. Over such a period of time, the steel constituting the strips placed in the ground is subjected to corrosion, which results in a loss of thickness, stiffness and strength of the strips. Strips are generally made of galvanized steel, which means that the steel is protected by a thin coating layer made of zinc. Corrosion of galvanized steel has been studied for more than 60 years in various conditions, yielding data to build conservative metal loss rates used for the design of reinforced earth walls. The main factors affecting corrosion are the pH, soil resistivity and concentration of dissolved sulfate and chloride ions. Submergence in salt water increases the potential for corrosion loss. For the design of reinforced earth walls, corrosion is taken into account very simply by means of the sacrificial thickness, that is, the metal thickness that will be lost by corrosion during the service life. This decrease in thickness, the sacrificial thickness, is calculated on the basis of field and laboratory data on buried galvanized steel. The design thickness of the reinforcing strips is the nominal thickness minus the sacrificial thickness. *Correspondence to: Emmanuel Bourgeois, IFSTTAR-MACS, 58 boulevard Lefebvre, F-75732 Paris Cedex 15, France. † E-mail: emmanuel.bourgeois@ifsttar.fr Copyright © 2011 John Wiley & Sons, Ltd. INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS Int. J. Numer. Anal. Meth. Geomech. 2011 Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/nag.1095