Lower Granite Lock and Dam Behavioral Guidance Structure

Owner: US Army Corps of Engineers - Walla Walla District

Colfax, WA
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Project Details

Advanced American Construction worked for the Army Corps of Engineers Walla Walla district to furnish and install structural steel for the Behavior Guidance Structure (BGS) on the Lower Granite Dam in Colfax, Washington. Over the length of the project, over 5 million pounds of fabricated steel was delivered via water transport, nearly 600,000 pounds of which was installed underwater. The BGS consisted of eleven pontoon sections, each 100 feet in length, that extended 55-80 feet beneath the water surface to form an underwater guidance wall. A complex bridal, buoy, concrete and anchor system was used to secure the floating guide wall in place. AAC received an outstanding performance evaluation for completion of this 2 year, $17 million project. AAC continued servicing the dam for 6 years following the installation, including operations, inspections and maintenance of the BGS system.
 

Project Highlights

· Furnished and installed fabricated structural steel for the BGS and simulated wells intake, consisting of 11 pontoon sections, each 100 feet in length.
· Approximately 4.9 million pounds of fabricated steel were delivered by water transport.
· 600,000 pounds of structural steel installed underwater, fastened by 250 expansion anchor bolts.
 

Project Photos