Bonneville Emergency Downstream Sill Repair

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Prime Contractor: Advanced American Construction
Owner: US Army Corps of Engineers

Bonneville, OR
September 2019 - September 2019
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Project Details

AAC was contacted by the Army Corps of Engineers to assist with de-watering the Bonneville Dam Navigation Lock on September 4, 2019.  The USACE had been experiencing an issue closing the downstream gate and wanted to investigate the lower sealing surface.   On September 5, AAC mobilized to the site and installed the stoplogs on the downstream side.   After the navigation locks were de-watered, AAC and the USACE identified a complete failure in the downstream miter gate sill.

On September 7, the USACE awarded AAC a contract to start the demolition of the failed sill.  AAC mobilized crews and equipment to install safe access and begin the demolition process.  Demolition was completed on September 12.

AAC’s crews, combined with some key subcontractors worked around the clock to repair and install a new lower gate sill.  The new lower gate concrete sill damage was identified and replaced in 22 days (3 days early by contract). 

AAC and the USACE team both worked long hours and through many challenges to make the project successful and injury free.

Project Highlights

  • Emergency mobilization of AAC crew and crane barge DB125
  • 22 Day duration (double shifts)
  • LiDAR mapping of existing gate and sealing surface
  • Concrete demolition
  • Several hundred drilled and epoxied reinforcing bars
  • Swift fabrication of rolled stainless steel sealing surface
  • Stainless steel seal plate field welding
  • Concrete and grout forming & pouring
  • Precision grouting of embedded plates

Project Photos


  • 2020 Awards

    • Award
      DJC Top Project - Bonneville Dam
      DJC Top Project - Bonneville Dam

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