San Francisco – Oakland Bay Bridge Tiedowns
Location: Yerba Buena Island, San Francisco, CA
General Contractor: American Bridge/Fluor Joint Venture
Equipment: C-6 Drill Rig
Work Performed: 20 EA 8” diameter tiedown anchors to 70’ depth, tested to 371 Kips
American Bridge/Fluor JV had a big problem when they couldn’t get the deck of the suspension span for the new Bay Bridge to deflect 8 inches for alignment, even after loading the end with over 1 million pounds. Their solution was to pull downward on the deck using cables anchored to Yerba Buena Island using tiedown anchors. Having recently completed another tieback job on the island successfully, Hillside Drilling was asked to help with the design and constructability of the system. Hillside was chosen to do the work, and designed and installed the anchors complete and tested well ahead of schedule.
“Hillside was extremely helpful during the design phase for the work. They helped with constructability issues, and executed the work safely and on-time.” Mark Macdonald, Project Manager, American Bridge/Fluor JV
(1) The HSD crew uses an air hammer to drill 70’ into the hard rock on Yerba Buena Island.
(2) The C6 drives casing to stabilize the top of the tiedowns.
(3) An HSD crew member cuts the top off of a casing.
(4) The 2 ¼” Ø Williams rod is hoisted and set into the hole by HSD’s truck-mounted 24-ton Grove crane.
(5) HSD crews splice a tail onto the bar for testing. The tiedowns will be tested to 371 kips.