One of the most recognizable landmarks in San Francisco – the famous Golden Gate Bridge – is awaiting a seismic retrofit project to the tune of $1 billion as a continuation of its long-term effort to make the bridge earthquake resilient. 

The Golden Gate Bridge, Highway and Transportation District has approved the project package that will make the main suspension bridge span, as well as its tower and other components that will be retrofitted in previous packages. It was said that the objective is to preserve functionality in the bridge in the wake of an earthquake on the San Andreas Fault line and the Hayward Fault line.

The retrofit will entail the replacement of new seismic isolation bearings, foundation reinforcement, and reinforcing connections to more effectively transfer earthquake loads to the structure. This is part of upgrading earlier stages that involved upgrading approaches as well as supporting structures, with only the most complex elements, such as the main span and towers, remaining to be completed in this final, technically challenging stage. The building process will take several years, with lane closures expected.

Across the bridge, there are also seismic safety measures being considered in the City of San Francisco, as well as other cities around the area. This could mean mandatory screenings as well as retrofits for many concrete buildings in the City. 

Taken in combination with these plans, there appears to be a growing concern in the area’s outdated infrastructure. Engineers working in the area specifically note that being able to withstand a seismic event as well as restore itself quickly is necessary on a number of levels.

The federal funding is playing an important part in this. There had been earlier commitments from the federal government that included about $400 million in federal funds that would go towards the Golden Gate Bridge seismic and safety retrofit. 

On a broader scale, it can certainly be said that the current retrofit is part of the major infusion of funds in the infrastructure area, as more money from the government in terms of transport-related infrastructure, resilience, or safety is having a positive effect on the construction industry. For the construction companies or engineers, Golden Gate could well serve as an example or prototype for implementing innovative seismic technology in the future.

According to local authorities, other areas that will be improved by the project include monitoring systems with real-time sensors installed in critical structural components to monitor movement and stress levels when earthquakes occur. 

This technology will be used to determine more effective means of maintenance based on these observations following earthquakes, as well as design retrofitting for other outdated bridges in the area. The adoption of technological monitoring systems is part of significant overall trends to "smart" infrastructure systems.