Meeting the Demands of Modern Grade Separation and Earth Retention: Characterization of Frictional Interference in Closely-Spaced Reinforcements in MSE Walls

PI: Armin Stuedlein
Dates: 03/01/2012 – 11/01/2013
Final Project Report: PacTrans-24-OSU-Stuedlein

The use of reinforced earth in the United States began in 1972; since then, Mechanically Stabilized Earth (MSE) walls have grown in popularity, and can be found along nearly every state and interstate highway corridor. Due to their inherent flexibility, MSE walls are being constructed to greater heights, in nonlinear geometries, with multiple tiers and with very high reinforcement spacing. For example, the four-tier West MSE wall at Sea-Tac International airport was recently constructed to 46 m height, and is now the tallest wall in the Western Hemisphere.

Tall walls (i.e., greater than 15 m in height) will proliferate due to increasing urbanization, right-of-way issues and wetland mitigation; in other words they offer a sustainable alternative to conventional grade separation, due to reduced mining and hauling of earth materials and reduced footprint. However, our understanding of the working stress behavior, including reinforcement strains and displacements, of tall, single and multi-tier walls is unsatisfactory.

The research proposed herein aims to address one of several knowledge gaps in the understanding of tall MSE wall behavior: prediction of reinforcement loads impacted by frictional interference of closely-spaced reinforcements associated with tall walls and/or walls in seismically active regions.