Seismic Refraction Tomography for Post-Flooding Roadway Reconstruction

In 2013 a massive flood washed through Big Thompson Canyon, in the Rocky Mountains of northern Colorado. Big Thompson Canyon is a very steep, minimally vegetated canyon, created by the 78 mile long Big Thompson River. During the historic 2013 flood large portions of US Highway 34 were either damaged or destroyed by washout, particularly along roadway segments not founded on bedrock. Temporary repairs were implemented; however, this being the second destructive flood in the canyon since 1976, the Colorado Department of Transportation decided to consider permanent, large-scale changes to the highway to improve the resiliency of the roadway during future flood events. Resiliency improvements include regrading riverside embankments, rerouting the highway, and adding scour resistant elements beneath the roadway. Two geophysical investigations were conducted using Seismic Refraction Tomography to aid engineers with construction and design of the planned improvements. Objectives of the first investigation were to map depth to competent rock and determining rippability for construction purposes, which were imaged in areas within the canyon that were inaccessible to a drill rig. The objective of the second investigation was to map depth to competent rock for design purposes. The geophysical results have, and will continue, to contribute to the design of a permanent roadway better able to withstand future flood events.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References;
  • Pagination: pp 137-157
  • Monograph Title: Proceedings of the 68th Highway Geology Symposium (HGS 2017)

Subject/Index Terms

Filing Info

  • Accession Number: 01642814
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 31 2017 4:36PM