July 23, 2010
Two Major Construction Projects Impact Golden Gate Bridge Sidewalks - Work Starts in Fall 2010
Sidewalks Remain Accessible to Bikes & Pedestrians
Phase 3A Seismic Retrofit Project | Main Cable Recoating Project
Click here to view the PowerPoint presentation made at the July 23 Board meeting.
PHASE 3A GOLDEN GATE BRIDGE SEISMIC RETROFIT PROJECT
Phase 3A of the Golden Gate Bridge (GGB) Seismic Retrofit project began in April 2008, retrofits the Marin Anchorage Housing (Figure 1 below) and Pylon N1, and is scheduled to be completed in 2011. As part of this critical earthquake strengthening project, portions of the GGB East and West sidewalks, within the limits of the 300-foot-long Marin Anchorage Housing (Figure 2 below), will be replaced over an eight (8) month-period starting in November 2010 and continuing through June 2011. The WEST sidewalk will be completed first and be followed by the replacement of the EAST sidewalk section. The sidewalk work will take approximately 120 days for each side. The construction effort is being planned to minimize impacts to all Bridge users.
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Figure 1: East Side View of the Marin Anchorage Housi |
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Figure 2: 300-foot-long section of the WEST sidewalk at the Marin Anchorage Housing |
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Figure 2: 300-foot-long section of the EAST sidewalk at the Marin Anchorage Housing |
Summary of Sidewalk Impacts to Accommodate
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| Location | When and Duration? | Impact to Pedestrians and Bicyclists |
| WEST Sidewalk @ Marin Anchorage Housing | 120 days (4 months)
- November 2010 through February 2011 |
WEST SIDEWALK will be CLOSED to bicyclists during the hours that it is normally open to bicyclists which includes weekends as well as weekdays from 3:30 p.m. to sunset.
Bicycle access will provided on the EAST sidewalk, with the pedestrians, on all days AND bicyclists will continue to have 24-hour access on the EAST sidewalk. |
| EAST Sidewalk
@ Marin Anchorage Housing |
120 days (4 months) - March 2011 through June 2011 |
EAST SIDEWALK, across the 300-foot-long section of the Marin Anchorage Housing, will be CLOSED DAILY to both bicyclists and pedestrians.
Bicyclists will be allowed access to the WEST sidewalk, 24 hours a day, seven days week. Pedestrians will have access on the remaining open portions of the EAST sidewalk during daylight hours but will not have access all the way across the Bridge sidewalk. |
GOLDEN GATE BRIDGE MAIN CABLE RECOATING PROJECT
To preserve the GGB’s two main cables for years to come, in October 2010, GGB work crews will begin erecting the scaffolding required to begin the three-year Main Cable Recoating project.
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Beginning on the WEST SIDE MAIN CABLE, fixed scaffolding will be erected along the 800-foot-long segment, located closest to the sidewalk level, at midspan. This segment will be split into two 400-foot-long sections with work starting on the 400-foot-long segment heading south from midspan and followed by the 400-foot-long section going north from midspan. Each 400-foot-long segment will take about 6 months to complete, or at total of about 1 year to complete the entire 800-foot-long segment. The fixed scaffolding will reduce the WEST sidewalk width from 10 feet to 7 feet for a distance of 400 feet. Bicyclists will be asked to walk their bikes through the work area. Once work is completed on the WEST SIDE MAIN CABLE, the work effort will shift to the EAST SIDE MAIN CABLE where a similar 800-foot-long section of fixed scaffolding will be erected for a period of approximately one year. |
BACKGROUND INFORMATION
Additional Main Cable Recoating Project Information
The two massive main cables of the GGB will undergo a three year recoating effort beginning in fall 2010. The project will start with installation of fixed position scaffolding (as described above) that will provide access to the lower portions of the MAIN CABLE so that GGB crews can:
- Clean the surface of the main cable
- Remove any deteriorated paint coatings
- Rough the surface of the main cable to be ready to accept new paint
- Make needed repairs
- Undertake required re-caulking of the cable bands
- Apply new primer and topcoat
GGB crews will also be accessing the higher portions of both of the main cable using elevated platforms that are currently in the design phase. Deployment of these platforms will require intermittent, temporary disruption to sidewalk traffic over the next several years. Once the planning is completed for this work, updated information will be provided.
Additional Seismic Retrofit Construction Project Information
The Golden Gate Bridge Seismic Retrofit Construction project was divided into three phases, two of which are now completed. Once the seismic retrofit construction is completed, the GGB will be able to withstand a nearby quake of 8.3 magnitude. Phase 1 retrofit the Marin viaduct structures and was completed in December 2001, using $71 million in toll dollars. Phase 2 undertook the retrofit of the San Francisco viaduct structures and Fort Point arch. It was completed in spring 2008 at a cost of $189 million. Following the events of September 11, 2001, Phase 3 was redesigned to incorporate additional security measures to aid in protecting against manmade threats as well as to seismic vulnerabilities. Phase 3A is a $125 million project that will be completed in 2011. Phase 3B will retrofit the main span, the two main towers, and south tower pier and fender. This final phase is estimated at $260 million and is planned to go out for construction bids in 2011 and take 3.5 years to complete.