Synthesis of Information Related to Highway Practices. Topic 52-18. Practices for New Rock Slope Design and Rockfall Mitigation

Design manuals for rock slope and rockfall mitigation have been in use by departments of transportation (DOTs) since the 1960s. Software tools have made complex data analyses faster and easier than in decades past. These manuals and software tools have proved invaluable to practitioners, helping them design rock slopes for highway modernization and the mitigation of rockfall hazards. While there are no standard goals and objectives for rock slope design and rockfall mitigation, some DOTs have formally or informally adopted their own design goals and objectives. Examples of design goals DOTs have adopted, either on a project-specific or statewide basis, include: (1) Acceptable percentages of rockfall debris that may exit the roadside ditch and reach travel lanes; (2) Improvement of the percentage of rockfall debris being caught in the roadside ditches; (3) General reductions in maintenance efforts or safety concerns; (4) Reductions in hazard "scoring" using evaluation systems such as the Rockfall Hazard Rating System; The objective of this synthesis is to document DOT practices for the design of new rock slopes and rockfall mitigation. Information to be gathered includes (but is not limited to): (1) Existence of formal design goals and objectives; (2) Connection between design goals with alternative project delivery, asset management, natural hazard resilience initiatives, highway system designation, or other risk management plans; (3) Factors that guide design (e.g., deterministic or probabilistic slope stability models, roadside ditch containment percentages, rockfall frequency, and other performance-based standards); (4) Risk tolerance considerations (5) Incorporation of aesthetic considerations in the design of new cut slopes (6) Design practice for mitigation measures (e.g., flexible rockfall barriers, rock bolts and dowels, draped mesh, rockfall attenuators, and pinned mesh systems) (7) Performance measures for rockfall mitigation Information will be collected through literature review, a survey of DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.


  • English


  • Status: Active
  • Funding: $45000
  • Contract Numbers:

    Project 20-05, Topic 52-18

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

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

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Gause, Jo

  • Start Date: 20200804
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01739673
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-05, Topic 52-18
  • Files: TRB, RiP
  • Created Date: May 18 2020 3:05PM