Best Highway/Bridge Project: Golden Gate Bridge Phase 3A Seismic and Wind Retrofit, San Francisco

Photo by John Walker
The project remediated hazardous materials and strengthened the north pylons, transverse cable guides and north anchorage housing.

Access constraints at the $90-million retrofit of one of the world's most iconic bridges made work treacherous, as did the more than 100,000 vehicles and thousands of pedestrians and bicyclists passing "through" the jobsite every day. Contractors also had to avoid any damage to the historically significant bridge.

Crews first remediated hazardous materials, including lead. Next came strengthening the north pylons, transverse cable guides and north anchorage housing.

Workers then replaced the existing north roadway and sidewalk decks. The steel-framed precast deck units (PDU) were pre-assembled off site to meet exacting specifications.

Two sideloaders, which are typically used to offload containers to the side of a truck using two cranes, were customized to remove the existing roadway and install the PDUs.

Safe and efficient access for performing the north anchorage work was provided by an innovative 250-ft-long by 25-ft-wide trestle system, comprised of steel members and timber crane mats supported by the existing bridge columns and ties. The trestle could safely lift multiple cranes, forklifts and other equipment to a height of 100 ft.

Each scope of work was planned down to the smallest detail, and the project team prepared more than 1,000 work plans for the owner, including step-by-step sequencing, stamped working drawings and supporting engineering calculations.

Key Players

Contractor Shimmick/Obayashi JV

Owner Golden Gate Bridge Authority

Lead Design Firm Thomas Jee & Associates

Subcontractors Bleyco Inc.; Gerdau; Jerry Thompson & Sons; Penhall Co.; Ghilotti Bros.; O’Grady Paving