Strength Reduction Factor for Geogrid Reinforcement at Elevated Temperatures

The Nevada Department of Transportation (NDOT) is currently considering using geosynthetic reinforcement for Mechanically Stabilized Earth (MSE) walls in Nevada, since it avoids corrosion, and is relatively cheaper and easier to install during construction. However, specific to conditions in Southern Nevada, geosynthetics may have other potential degradation issues e.g., uncertainty of long-term field performance at elevated temperatures. These temperatures may substantially degrade tensile strength and creep of these materials since their mechanical behavior is temperature-sensitive. This study focused on tensile strength degradation of geogrids due to many MSE wall failures being tensile-related. A rational scheme is proposed to obtain a more realistic minimum strength reduction factor for design, i.e., RFD, at elevated temperatures. The scheme combines the effects of the following important design factors: site-specific air temperature history; numerical thermal modeling to establish soil backfill temperatures; and laboratory testing at elevated temperatures. It addresses the effects of both long-term exposure to elevated temperatures and load level on allowable strength of geogrids. The proposed approach has been illustrated using temperature data for Las Vegas, Nevada and is easily adaptable to any location and geosynthetic reinforcement. It was found that the minimum recommended RFD value should be increased from 1.1 to 1.25 when the evaluated uniaxial high-density polyethylene (HDPE) geogrid is used in Las Vegas for a service period of 100 years.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFS70 Geosynthetics.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Kasozi, Andrew M
  • Siddharthan, Raj V
  • Bafghi, Abbas A
• 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; Tables;
• Pagination: 17p
• Monograph Title: TRB 93rd Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Backfilling; Corrosion; Creep; Degradation failures; Geogrids; High temperature; Mechanically stabilized earth; Slope stability; Tensile strength
• Identifier Terms: Nevada Department of Transportation
• Geographic Terms: Las Vegas (Nevada)
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 01514944
• Record Type: Publication
• Report/Paper Numbers: 14-3014
• Files: TRIS, TRB, ATRI
• Created Date: Feb 21 2014 3:16PM