The Golden Gate Bridge is preparing for a seismic restoration of almost $ 1 billion, which will focus on the two main towers, the lateral extensions of 1,125 feet and the reduction of lead paint.
Halmar International is directing construction as a general construction/contractor (CMGC). The company, hired in March 2024, directs the planning and works closely with the district to complete the construction plans.
“With the CMGC method, he is allowed to bring the contractor during the design phase, and then they will work with you as part of the design team and bring contributions to the design regarding the construction,” says John Eberle, a district engineer with the Golden Gate Bridge, the road and the transport district, the agency in charge of maintaining the bridge.
Halmar was brought aboard when the design was about 85% complete. The firm is currently developing means and methods for implementing retrophic, including trying to find out the best way to access the bridge during construction when officials project about 200 manuals a day during the full peak.
Halmar was forced to postpone to the agency to comment. In an Instagram publication, Estimator Christian George said that 3D printing is one of the tools used to examine various scenarios.
“The bridge works with more than 100,000 daily vehicles, along with pedestrians and bicycles on the sidewalks, as well as our own crews, so Halmar has to find how workers will get to the place without affecting traffic and pedestrians, and this is quite difficult,” says Eberle.
The project is the last phase of a series of seismic updates of the bridge that began after the 8.3 Loma Prieta earthquake hit the California central coast throughout the San Andreas Fallas system in 1989. The analysis has found that 8.3 is the credible maximum earthquake that could hit the region.
“Although the Golden Gate Bridge can safely endure a great earthquake today, the final phase of the seismic restoration will help to ensure that the bridge remains in service after a significant natural disaster and will help our region to respond and recover -in the following days, and months,” he says, “he says,” he says, “he says,” he says, “he says,” he says, “he says.”
Phase 1 updates to historical structure began in 1997 and focused on the Marin (North) approach viaduct. The $ 79 million project consisted of structural updates and strengthening of structural components and the modification of structural responses to better respond to strong no damage.
Phase 2 began in June 2001 and was completed in July 2008. The $ 189 million project spanned the structural restoration of the South Approach viaduct, South Anchorage Housing, Fort Point Arch and South Pylons.
The 3rd phase passed from 2008 to 2014 and included the restoration of the North Anchorage and Pylon N1 casing. The $ 125 million project was funded by a combination of federal funds along with regional and state headphones.
This $ 870 million current project, known as 3B1, is funded by $ 400 million through a federal bridge investment program, $ 200 million from the California Department of Transportation and $ 270 million in district capital reserves.
The highlight of this phase is a restoration of the two towers 746 feet high. At the base of the towers, the crews will be sinking into steel plates 2 inches thick, which are about 40 feet high to strengthen the perimeters and strengthen the transverse tower tips at the level of the road.
The crews will add 28 energy dissipation devices in the two lateral supplies of 1,125 feet in length. Fourteen of the devices will be installed on each of the side features where they are connected to the hardened features at the level of the road. The dissipation devices are made with stainless steel, weigh up to 26,000 pounds and can stretch up to 20 feet depending on their configuration.
“The devices will dissipate the energy of an earthquake so that this force does not be taught in the hardened plot; they will reduce the force so that you do not have to restore all the members of the bridge,” says Eberle.
In the hardened transits, below the road cover, the crews will eliminate and replace the upper side protection system and strengthen part of the connection.
One of the last elements of phase 3b1 is the reduction of the existing painting system from the 1930’s. Eberle says it contains about 68% weight by weight and that much of the bridge still has lead everywhere.
An example of the logistics challenge is the south tower, which is 1,000 feet on the coast. “To adapt it, the crews must go down and then enter the tower and do very surgical work, eliminating existing fixers and putting new steel plates without damage or creating havoc with the existing structure and tensions,” says Eberle.
Eberle says the district plans to award a project construction contract this December and then launch a notice to proceed in January. Halmar will probably be the general contractor, assuming that the parties can agree on a price. If they cannot reach a price agreement, the project will be released to other contractors.
When the 3B1 is completed by 2031, the district will begin 3B2, which will cost about $ 900 million and will focus on adapting the main extension of 4200 feet in length.
