Rockfall and Rockslide Mitigation Options with Rocksheds and Real-time Slope Monitoring along Interstate 70 in Glenwood Canyon, Colorado

Interstate 70 is the primary east-west route across Colorado. The interstate crosses a multitude of geologic hazards, but mile marker 125 in Glenwood Canyon has been a site prone to large scale rockfall events resulting from rockslides. At this location, rockslides closed the interstate five times since 2003. Closures ranged from partial lane closures to full closure of the interstate for two to three days; and the full costs of highway repairs and emergency response have exceeded $2,500,000. In two cases the westbound lanes of the interstate were closed for up to 60 days to allow for highway repairs. The westbound lanes at this location are supported on retaining walls and a steel girder bridge supports the eastbound lanes. The rockfall events have destroyed sections of the retaining wall and punctured holes ranging from 2 meters to 5 meters in diameter in the bridge deck. Detour routes when the interstate is closed consist of a 325 km long bypass. Consequently, indirect and safety costs from closures are significant, up to several hundred thousand dollars per day of closure. March 2010 was the last incident that caused significant damage to the highway. This incident resulted in a 5 meter hole in the bridge deck and closed the highway for three days for rock mitigation. The westbound lanes were closed for nearly 60 days for bridge repairs. After the event, which was repaired through FHWA Emergency Repair procedures, it was recommended that CDOT investigate long term rockfall and rockslide mitigation options. The investigation consisted of providing mitigation and management options for dealing with the ever present rockfall hazard. The investigation included lidar scanning of the slopes; remote mapping; two and three dimensional rockfall analysis; rock shed mitigation, design and evaluation; and remote slope stability radar (SSR) scanning that was conducted as a test for 22 hours. The results of the study outline of the mitigation options, and combination of mitigation and management of asset features are presented.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; Tables;
  • Pagination: pp 122-134
  • Monograph Title: Proceedings of the 63rd Annual Highway Geology Symposium (HGS 2012)

Subject/Index Terms

Filing Info

  • Accession Number: 01661537
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 13 2018 12:34PM