AWARD-WINNING INNOVATION PROTECTS THE ENVIRONMENT

This article describes an innovative technique that is being used by the California Department of Transportation (Caltrans) to protect sensitive marine life from pile-driving noise during the new San Francisco Oakland Bay Bridge (SFOBB) East Span Project. One of the requirements of the project was the placement of eight-foot diameter steel test piles 350 feet into the Bay. Driving the piles into place required one of the world’s largest hydraulic hammers that is capable of delivering up to 1.25 million foot-pounds per blow. The article describes how Caltrans first tested bubble curtains during the construction of the new Benicia-Martinez Bridge. The technology involves a circular wall of bubbles generated from a perforated pipe that sits on the mud line and is charged with compressed air. A variation of the bubble curtain resulted in the bubble tree, which ultimately removed more than 99 percent of the noise energy without disrupting the contractor’s operation. For the Skyway component of the SFOBB Project, specifications called for a multi-level bubble curtain with a high bubble density to be used during high tidal currents. The article notes that these technological advancements that Caltrans has developed established the state-of-the-art in friendly pile-driving practices. A group of experts retained by Caltrans has evaluated the literature dealing with noise impacts on fish, with focus on noise resulting from pile-driving in aquatic environments. Their efforts have led to a report titled “The Effects of Sound on Fish.” The article also relates how Caltrans has formed a working group with other entities such as the FHWA, California Department of Fish and Game, the Army Corps of Engineers, NOAA Fisheries, and the U.S. Fish and Wildlife Service. Focus of the group is to promote further protection of marine life in pile-driving projects.

• Corporate Authors:

  California Department of Transportation

  1120 N Street
  Sacramento, CA  United States  95814
• Authors:
  • Jones, K
  • Mckee, D C
• Publication Date: 2005

Language

• English

Media Info

• Features: Figures; Photos;
• Pagination: pp 7-11
• Serial:
  • California Transportation Journal
  • Volume: 1
  • Issue Number: 2
  • Publisher: California Department of Transportation

Subject/Index Terms

• TRT Terms: Aquatic life; Bridge engineering; Marine biology; Pile driving
• Identifier Terms: San Francisco-Oakland Bay Bridge
• Subject Areas: Design; Environment; Highways;

Filing Info

• Accession Number: 01005598
• Record Type: Publication
• Source Agency: UC Berkeley Transportation Library
• Files: BTRIS, TRIS, STATEDOT
• Created Date: Oct 19 2005 2:04PM