GEOLOGIC CHARACTERIZATION, COLORADO RIVER BRIDGE FOUNDATIONS, HOOVER DAM BYPASS

The Colorado River Bridge is a key element of the 5.6 km (3.5-mile) U.S. Highway 93 Hoover Dam Bypass Project from Clark County, Nevada to Mojave County, Arizona. The Central Federal Lands Highway Division of the Federal Highway Administration (FHWA) is the managing partner responsible for project delivery. The planned 579 m (1,900-foot) long Colorado River Bridge will cross rugged bedrock setting in Black Canyon 460 m (1,500 feet) downstream of the historic Hoover Dam and 274 m (900 feet) above river level, with a 332 m (1,090-foot) main arch and seven approach spans. Various alternative bridge types were evaluated for the site based on aesthetic, technical suitability and cost criteria, the selected design includes steel box girders, composite concrete deck, and reinforced concrete arch rib and pier columns, foundations and abutments. Geotechincal characterization of the bridge site and particularly the skewback foundations required specialized approach in the rugged bedrock environment, including 3-D laser scanning of the canyon walls, geologic mapping by multiple methods, core drilling with specialized rigs/access equipment, optical televiewer borehole logging of rock fracture data, in-situ borehole jack testing and down-hole seismic surveys, and laboratory testing of rock strength. Geology of the bridge site consists of Tertiary-age volcanic and sedimentary rocks, with the key skewback foundation areas composed of variable quality but generally low-strength massive tuff and strong but highly irregular basalt dikes.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0784407444
• Corporate Authors:

  American Society of Civil Engineers

  Geo Institute, 1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • LaFronz, N J
  • Peterson, D E
  • Turton, R D
  • Anderson, S
• Conference:
  • Geotechnical Engineering for Transportation Projects, Geo-Trans 2004
  • Location: Los Angeles, California
  • Date: 2004-7-27 to 2004-7-31
• Publication Date: 2004

Language

• English

Media Info

• Features: Figures; Tables;
• Pagination: 10 p.
• Serial:
  • ASCE Geotechnical Special Publication
  • Issue Number: 126
  • Publisher: American Society of Civil Engineers

Subject/Index Terms

• TRT Terms: Aesthetics; Bedrock; Boreholes; Box girder bridges; Bridge decks; Bridge foundations; Bypasses; Columns; Composite materials; Concrete; Dam foundations; Design; Geological events; Geological surveying; Historic bridges; Logging; Maps; Piers (Supports); Project management; Rivers; Steel
• Geographic Terms: Arizona; Colorado River; Nevada
• Subject Areas: Administration and Management; Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00988661
• Record Type: Publication
• ISBN: 0784407444
• Report/Paper Numbers: Volume II
• Files: TRIS
• Created Date: Apr 13 2005 12:00AM