Design and Finite Element Analysis of a Single Slope Median Wall for Grade Separation

This research explored a design option of median barrier for use as grade separation on split level highways. Such type of barrier needs to provide design and construction flexibility as shoulder elevations vary along the roadway, and also perform as a retaining wall. The proposed barrier design is a single slope median barrier of a total maximum height of 112.5 inches, a soil backfill height of maximum 60 inches acting on one side, and 4H:21V slope on both sides of the barrier. Stability and yield line analysis for the proposed barrier design were investigated to evaluate the structural ability to provide adequate stability with respect to sliding, overturning, and bearing capacity. Crashworthiness of the barrier design was investigated through finite element analyses at AASHTO "Manual for Assessing Safety Hardware" (MASH) Test Levels 3 and 4. The authors optimized the minimum barrier segment length needed to resist soil forces and MASH impact conditions. Analyses resulted in acceptable barrier performance according to the criteria set forth in MASH for longitudinal barriers, and soil retention according to the Load and Resistance Factor Design (LRFD) method suggested by AASHTO 2007. Application of this design would result in two major benefits. First, it will eliminate the need for a reinforced moment slab to prevent overturning, simplifying the design and construction of the retaining wall. Second, the new design has a limited foundation depth allowing it to clear catch basins and utility conflicts.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFB20 Roadside Safety Design. Alternate title: Design and Finite Element Analysis of Single Slope Median Wall for Grade Separation.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Silvestri Dobrovolny, Chiara
  • Arrington, Dusty R
  • Brackin, Michael S
  • Bligh, Roger P
  • Hangul, Ali R
• Conference:
  • Transportation Research Board 93rd Annual Meeting
  • Location: Washington DC
  • Date: 2014-1-12 to 2014-1-16
• Date: 2014

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: 16p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Crashworthiness; Design; Finite element method; Height; Load and resistance factor design; Median barriers; Retaining walls
• Identifier Terms: AASHTO Manual for Assessing Safety Hardware
• Uncontrolled Terms: Slope (Angle)
• Subject Areas: Design; Highways; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 01514483
• Record Type: Publication
• Report/Paper Numbers: 14-2720
• Files: TRIS, TRB, ATRI
• Created Date: Feb 18 2014 5:21PM