Foundation Design for High Tension Cable Guardrails

High tension cable guardrail is becoming increasing popular in median and roadside applications due to the promise of reduced deflections upon impact and reduced maintenance. As the performance of these systems is observed in service, there is a growing concern over the end anchorage foundation performance of current systems. Foundations for high tension systems must not only be capable of restraining the impact load of a vehicle but must also restrain the initial pretension on the cable system as well as temperature induced loads. While it may be acceptable for many roadside safety devices to require foundation repair after impact, foundation failure due to environmentally induced loads would be a serious maintenance problem. As initial tension and temperature induced loads can be greater than those loads applied during impact, this type of loading must be considered in foundation design. Foundation deflection can reduce cable tension, increasing deflection of the system during impact and letting the cables sag after impact. The soil conditions in which these foundations are placed vary significantly. This report considers the potential impact, tension, and temperature loads and develops a set of suggested foundation designs to accommodate a range of in situ soil conditions. These designs will vary significantly in different areas around the nation due to variations in both weather and in situ soil conditions. Deflection during full-scale crash tests may not accurately represent the foundation deflection that will be experienced in the field.

• Record URL:
  https://digitalcommons.unl.edu/ndor/91
• 
• Supplemental Notes:
  • This document is disseminated under the sponsorship of the Department of Transportation University Transportation Centers Program.
• Corporate Authors:

  University of Nebraska, Lincoln

  Midwest Roadside Safety Facility
  2200 Vine Street, Whittier Building
  Lincoln, NE  United States  68583-0853

  Mid-America Transportation Center

  University of Nebraska-Lincoln
  2200 Vine Street, PO Box 830851
  Lincoln, NE  United States  68583-0851
• Authors:
  • Zhu, Ling
  • Rohde, John R
  • Terpsma, Ryan J
• Publication Date: 2010-6

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Figures; References; Tables;
• Pagination: 49p

Subject/Index Terms

• TRT Terms: Barriers (Roads); Cables; Design; Foundations; Guardrails; Highway safety; Impact tests; Roadside; Tension
• Subject Areas: Bridges and other structures; Design; Highways; I20: Design and Planning of Transport Infrastructure;

Filing Info

• Accession Number: 01340405
• Record Type: Publication
• Report/Paper Numbers: TRP-03-236-10
• Files: UTC, TRIS
• Created Date: May 18 2011 1:23PM