Phase 3A (2008 - 2014)
The third and final phase of the Golden Gate Bridge Seismic Retrofit Construction Project was separated into two sub-phases.
Phase 3A: Retrofit of the North Anchorage Housing and Pylon N1
Phase 3A is estimated at $125 million and is being funded using a combination of federal funds along with regional and state earmarks. A construction contract for Phase 3A was awarded in April 2008. Construction was completed in 2014.
Phase 3B (2025 - 2029)
Phase 3B: Retrofit of the Main Suspension Span, Main Towers, South Tower Pier and Fender
Phase 3B is estimated at $879 million and will be funded using a combination of federal funds along with regional and state earmarks. Phase 3B will go out to bid in 2023 and take approximately 6 years to complete.
The seismic retrofit measures for these phases consist of strengthening foundations, installation of micropiles and rock bolts, construction of reinforced concrete shearwalls, replacement of the housing roof/roadway deck with a pre-cast concrete slab-on-steel stringer deck system involving nighttime lane closures, and other structural modifications.
Construction is slated to begin in early 2025 and finish in 2029.