DEVELOPMENT OF THE SIMPLIFIED METHOD FOR INTERNAL STABILITY DESIGN OF MECHANICALLY STABILIZED EARTH WALLS

In 1994, a technical working group under the auspices of the T-15 Technical Committee on Substructures and Walls of the American Association of State Highway and Transportation Officials (AASHTO) Bridge Subcommittee, was formed to reevaluate the design specifications for mechanically stabilized earth (MSE) walls contained in the AASHTO Standard Specifications for Highway Bridges (1996). One of the areas of focus was the internal stability design of MSE walls. Several methods for calculating the backfill reinforcement loads were available at that time in the AASHTO Standard Specifications, and the intent was to unify the design methods to simplify and clarify the specifications. To accomplish this, full-scale MSE wall case history data were gathered and analyzed so that the unified method developed could be calibrated to the empirical data, since all of the methods available were empirical in nature. The effect of simplifications in the method, such as how vertical soil stresses are calculated and how reinforcement stiffness is considered in the design, could also be evaluated with these full-scale wall data to ensure that the unified method developed was adequately accurate. From this effort, the AASHTO Simplified Method was developed. This report summarizes the development of the Simplified Method. It uses a number of full-scale MSE wall case histories to compare the prediction accuracy of the Simplified Method to that of the other methods currently available and focuses primarily on steel reinforced MSE walls. The theoretical assumptions used by the Simplified Method, as well as the other methods, are also evaluated and compared in light of the empirical evidence. This evaluation showed that the prediction accuracy of the Simplified Method is at least as good as that of the other methods, while the Simplified Method still simplifies calculations. This evaluation also showed, however, that all of the methods have limitations that must be considered.

• Record URL:
  http://www.wsdot.wa.gov/research/reports/fullreports/513.1.pdf
• 
• Corporate Authors:

  Washington State Department of Transportation

  Transportation Building, 310 Maple Park Avenue SE, P.O. Box 47300
  Olympia, WA  United States  98504-7300

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Allen, T
  • Christopher, B
  • Elias, V
  • DeMaggio, J
• Publication Date: 2001-7

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 108 p.

Subject/Index Terms

• TRT Terms: Accuracy; Calculation; Case studies; Design methods; Highway bridges; Mechanically stabilized earth; Reinforcing steel; Retaining walls; Specifications; Stability (Mechanics)
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00921488
• Record Type: Publication
• Report/Paper Numbers: WA-RD 513.1,, Research Report
• Files: TRIS, ATRI, USDOT, STATEDOT
• Created Date: Mar 8 2002 12:00AM