Quantifying Long-Term Performance of Draped and Flexible Fence Rockfall Protection Systems

Rockfall protection systems have been in service along roadways in Europe and the United States for more than 40 years. Rockfall protection systems utilizing steel netting to control the rockfall include ring-net barrier fences, cable-net barrier fences, draped cable-net, draped wire-mesh, and attenuators. Many of the systems are proprietary. These systems are intended to control rockfall and/or reduce the potential for rock debris to fall within highway alignments. The protection systems include components such as wire rings, wire rope, wire rope nets, wire mesh, posts, pins, fasteners, and breaking elements. These components are usually designed and rated based on testing in terms of energy capacity or energy reduction of a single rockfall event with some consideration for serviceability after specific impacts. However, the long-term performance and maintenance issues of these systems are a growing concern since many departments of transportation that have installed these systems are faced with significant maintenance, repair and/or replacement costs once a rockfall event occurs. The objective of the research is to provide owners and manufactures of rockfall systems with guidelines to evaluate vulnerability and maintenance issues associated with rockfall protection systems that use steel netting. The report will also provide estimates for design life expectancies of various systems. The design guidelines should also include a method to determine when to replace and upgrade these types of rockfall protection systems. Initiation of this work is urgent. The payoff from this research includes a safer highway system, improved prioritization of funds, reduced maintenance and clean-up costs, and reduced life-cycle costs associated with design, construction, and maintenance of rockfall hazard protection systems. Results of the research will be useful to transportation agencies charged with managing rockfall hazards. In the United States, thousands of rockfalls occur annually along highways; consequently, rockfall protection systems have become an important component of highway safety. Often these protection systems are placed along scenic sections of highways carrying large volumes of traffic, particularly during tourist season and for seasonal recreation destinations. Products from this research, which include a recommended practice for inspection and review of the service life, are needed for better selection of materials and components incorporated into rockfall protection systems. Currently, there are no well-defined provisions or protocols for condition assessment and service life modeling of rockfall protection systems. The recommended practice developed as part of this research would be in a format consistent with AASHTO requirements.<p> </p>

Language

  • English

Project

  • Status: Proposed
  • Funding: $150000.00
  • Contract Numbers:

    Project 24-35

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Reynaud, David

  • Start Date: 20100618
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 26560

Subject/Index Terms

Filing Info

  • Accession Number: 01463898
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 24-35
  • Files: TRB, RiP, USDOT
  • Created Date: Jan 3 2013 2:32PM