Synthesis of Information Related to Highway Practices. Topic 52-18. Design Practices for Rock Slopes and Rockfall Management

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 and evaluate rock slopes adjacent to highways and the management of rockfall hazards. While there are no national standard goals and objectives for rock slope design and rockfall management, 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 reach the 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; and (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 rock slopes and rockfall management. Information to be gathered includes (but is not limited to): Percentage of new and rehabilitated rock slopes within DOTs; Agency versus consultant or contractor design (approximate percentages); Documented design goals and objectives; Consideration of project delivery, constructability, maintenance, asset management, aesthetics, life cycle costs, resilience initiatives, highway system designation, or risk management plans in the design process; Technical factors that guide design (e.g., deterministic or probabilistic slope stability models, rock mass characteristics, roadside ditch containment percentages, rockfall frequency, new versus rehabilitated rock slopes, performance-based standards); Risk considerations for rock slope design and management (e.g., consequences of slope failure, rock fall, impact on the travelling public, risk sharing, monitoring); Design practice for mitigation measures (e.g., rockfall barriers, rock bolts and dowels, draped mesh, rockfall attenuators, pinned mesh systems); and Performance measures for rock slope and rockfall mitigation (e.g., percentage of rockfall retained in ditches, number of repeat failure incidences). 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.

Language

  • English

Project

  • 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

  • Performing Organizations:

    Landslide Technology

    Portland, OR  United States 
  • Principal Investigators:

    Beckstrand, Darren

  • Start Date: 20201016
  • 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