Developments in MSE Wall Research and Design

Abstract

Mechanically stabilized earth (MSE) walls constructed with steel and geosynthetic reinforcing elements are now well-established technologies. The paper gives a brief historical overview and then a review of current approaches to the internal stability design of these systems including strength-based limit equilibrium methods and reinforcement stiffness-based methods. Examples of full-scale wall testing in North America and Japan are described which have proved valuable to quantify the accuracy of current methods used to calculate reinforcement loads in MSE walls under operational (in service) conditions. The paper explains how these measured data are used to develop simple load and resistance models for pullout and rupture limit states that are more accurate and amenable to reliability-based design. These models are candidates for future editions of the AASHTO code in the USA and the Canadian Highway Bridge Design Code. An example is given that shows that MSE walls are the likely choice based on rigorous sustainability assessment when compared to gravity and cantilever wall options. Finally, the movement towards reliability-based internal stability analysis and design of MSE walls, and the link to load and resistance factor design (LRFD) calibration are explained.