3,000+ SF Buildings at Risk of Earthquake: Report
San Francisco has identified over 3,000 concrete buildings that could be at high risk of collapsing in the event of a major earthquake, according to a preliminary draft obtained by NBC News. The city government worked with a group of structural engineers to develop the list of older concrete buildings that have the potential for non-ductile concrete vulnerability. The San Francisco Chronicle building, dating back to 1924, is one of the older buildings on the city’s list for evaluation and potential retrofitting.
Megan Stringer, president of the Structural Engineers Association of Northern California, said some buildings, such as Twitter’s headquarters dating back to the 1990s, do not have enough reinforcing steel inside the concrete to make them earthquake safe. The group of engineers is working with the city to develop a plan to identify and retrofit older concrete buildings in San Francisco. “We are working to fix these buildings. We know that it’s an issue and we are working to fix that,” said Stringer.
However, not every building on the draft list published on NBC News will need retrofitting, and some are listed by mistake, according to Stringer. The final draft is still in the works. In a statement to NBC Bay Area, Brian Strong, San Francisco’s chief resilience officer, noted that “the inclusion of a building on the list does not necessarily mean that the building is at a greater risk compared to other buildings from the same period. We look forward to sharing more information and reaching out to building owners and community members as we better understand which buildings may be most vulnerable,” he said.
The city is also working with housing rights advocates like Maria Zamudio to ensure tenants won’t be displaced by the retrofitting of some apartment buildings. “Full and proper noticing for tenants, making sure that relocation is thought about,” said the organizing director of the Housing Rights Committee in San Francisco.
San Francisco is developing a Concrete Building Safety Program in collaboration with national experts and local stakeholders. The programme will aid in the protection of lives and make the city more resilient in the event of an earthquake. The public will have a chance to weigh in on the draft ordinance, which is to be published this summer with plans for the concrete buildings.
The disclosure of potentially risky buildings comes after authorities in San Francisco introduced strict new regulations requiring retrofitting of wood-frame structures to make them more resilient following the 1989 Loma Prieta earthquake. This is a part of the city’s effort to ensure the safety of residents and the preservation of historic buildings, which have come under scrutiny in recent years.