State Highway 140, Ferguson Rock Slide Bypass, near El Portal, Mariposa County, California

This paper gives a brief history of the Ferguson Rock Slide in Mariposa County, California. The paper describes the steps taken by the California Department of Transportation (Caltrans) to deal with the negative impacts of the slide. Caltrans has dealt with effects of the slide in recent years by scaling back the slide and clearing fallen materials on the roadway. In May 2006, the rockslide accelerated causing permanent closure of State Route 140 to traffic between the city of Mariposa and Yosemite National Park. After reviewing several options, it became apparent only one solution could remedy this problem; traffic would have to bypass the slide area. Of several bypass options introduced, none enabled Caltrans to open State Route 140 to traffic within a reasonable time to minimize economical and social impact to the community. The Bridge Department Team introduced the idea of installing single span Acrow panel bridges to span the Merced River on both sides of the slide. The Bridge Department Team and geological reports identified a route that could be used to bypass the slide. The route would follow an abandoned railway grade alignment located on the right bank of the Merced River, which is on the opposite side of the slide. As this route was in close proximity to the slide it would require continuous monitoring of the main body of the rock slide mass in real or near real time. This is important to detect any preliminary movement that may indicate a catastrophic failure of the slide and provide a warning to Caltrans allowing a timely closure of the bypass to travelers. The bypass, consisting of 2 Acrow panel bridges and a roadway, was constructed in 2 stages. The first stage opened to 1-way traffic on July 30, 2006, with the second stage following August 18, 2006. Both stages were open to traffic during daylight hours only.

• Corporate Authors:

  Multidisciplinary Center for Earthquake Engineering Research

  State University of New York, 107 Red Jacket Quadrangle, P.O. Box 610025
  Buffalo, NY  United States  14261-0025
• Authors:
  • Kassis, Hanna F
  • Cunningham, Robert P
• Conference:
  • The Second US-Taiwan Bridge Engineering Workshop
  • Location: San Mateo CA, United States
  • Date: 2006-9-21 to 2006-9-22
• Publication Date: 2006

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Photos;
• Pagination: 12p
• Monograph Title: Proceedings of the Second US-Taiwan Bridge Engineering Workshop

Subject/Index Terms

• TRT Terms: Bypasses; Highway bridges; Rockslides; State departments of transportation
• Identifier Terms: California Department of Transportation
• Uncontrolled Terms: Panel bridges
• Subject Areas: Bridges and other structures; Design; Geotechnology; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 01079612
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 22 2007 10:15AM