U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590

Skip to content U.S. Department of Transportation/Federal Highway AdministrationU.S. Department of Transportation/Federal Highway Administration

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

This report is an archived publication and may contain dated technical, contact, and link information

Publication Number: FHWA-RD-03-048
Date: September 2003

Effects of Geosynthetic Reinforcement Spacing on The Behavior of Mechanically Stabilized Earth Walls

Previous | Table of Contents | Next

Chapter 7. Conclusions And Recommendations

The results of numerical analysis of MSEWs with modular block facing and geosynthetic reinforcement using program FLAC have been presented. The emphasis was to identify the effects of reinforcement spacing on wall behavior, considering the effects of soil strength, reinforcement stiffness, connection strength, secondary reinforcement layers, foundation stiffness, and reinforcement length. Parametric studies were conducted on numerical models constructed, layer by layer, up to failure under gravity loading with reinforcement spacing in the range of 0.2–1.0 m, 3 soil types with different soil strength, 2 different foundation conditions with respect to soil stiffness, 3 different connection conditions, and 2 reinforcement stiffness values. The material properties were based on literature data representing typical values used in design practice. The reinforcement length was kept constant, equal to 1.5 m in models investigating the wall response with respect to failure. It was increased to correspond to length-to-height ratio in the range of 0.3–0.5 in models investigating the effects of reinforcement length on wall stability. The most important conclusions are summarized below:

The results of the parametric study clearly show the influence of reinforcement spacing, connection strength, reinforcement stiffness, and soil properties on the behavior of MSEWs with modular block facing and geosynthetic reinforcement. In general, the MSEWs can sustain higher loads with less deformation when reinforcement spacing is smaller and connection load is higher. Since the emphasis of the current study is on the effects of reinforcement spacing on wall behavior, the study was designed to investigate and quantify these effects with respect to failure. The effects of connection strength and reinforcement stiffness were investigated, but only qualitative evaluation of their effects are possible.

Further parametric studies that implement experimental data from laboratory and large-scale tests must be conducted to quantify the effects of connection strength, reinforcement stiffness, and soil properties such as soil stiffness and dilatancy on the behavior of MSEWs.

The reported numerical simulations supported by laboratory and large- scale tests and further numerical analysis may be used to verify or modify the existing methods of analysis and MSEW design with modular block and close reinforcement spacing.


Previous | Table of Contents | Next