Thirty-nine high rises in San Francisco are at risk of collapse in a major earthquake, according to a new study by the U.S. Geological Service (USGS).
The vulnerable buildings (known as welded steel moment-frame buildings) were constructed by using a flawed technique to weld columns and beams together. This technique was found to be less resilient to seismic activity after the 1994 Northridge earthquake in Los Angeles where critical joints were damaged in several buildings that had been welded.
The building code was revised in the mid-1980s to require more stiffness, and then again in the mid-1990s to correct the defective welding technique. San Francisco outlawed the technique in1994 after damage from the Northridge quake on high rises was discovered. The list of vulnerable structures includes the former Bank of America building, the headquarters of Pacific Gas and Electric, three hotels, and the Salesforce West tower.
San Francisco has offered incentives to repair at-risk buildings. In 2009, the city expedited permits and agreed to waive fees for so-called “soft-story buildings” that have garages or windows on the bottom floor.
Related Stories
Codes and Standards | May 26, 2020
Architectural Reuse Council will step up efforts to reuse construction waste
Cabinets, appliances, lighting, and lumber diverted from landfills to be repurposed.
Codes and Standards | May 26, 2020
Is CLT really a green solution?
Sustainability depends upon forest stewardship, product manufacturing process.
Codes and Standards | May 20, 2020
St. Louis is first Midwest city to pass building energy performance standard
Allows owners broad flexibility on how to achieve goals.
Codes and Standards | May 20, 2020
Supreme Court says Georgia cannot copyright its entire official code
Ruling may have implications for other states claiming copyright for building codes.
Codes and Standards | May 18, 2020
Strategies to reduce personal contact in multifamily properties
Design can improve health amid COVID-19 pandemic.
Codes and Standards | May 18, 2020
Canada Green Building Council says building industry lacks zero-carbon skills, knowledge
Net-zero target requires shift in thinking and practices.
Codes and Standards | May 18, 2020
California’s grid can support all-electric buildings
Load-shifting will help reduce peak demand.
Codes and Standards | May 15, 2020
European cities to revamp transportation after pandemic reopening
Road closures, new rules for public transit will be imposed.
Codes and Standards | May 14, 2020
Washington State construction industry restart plan has three phases
In state with earliest COVID-19 cases, advisory group developing priorities based on risk.
Codes and Standards | May 14, 2020
More mass timber beam and column options available in the U.S.
Freres Lumber unveils new line of structural elements suitable for high-rise buildings.
