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 | Mar 23, 2021
The 15-minute city may not work in much of North America
Segregated neighborhoods and car-centric cities may not adapt to the European model.
Codes and Standards | Mar 22, 2021
Think tank offers plan for new approach to reduce neighborhood poverty
Strategy uses more targeted approach to invest in low-income areas.
Codes and Standards | Mar 19, 2021
California city bans construction of new gas stations
Existing stations will not be allowed to add more pumps.
Codes and Standards | Mar 18, 2021
Congressmen ask Biden to tackle rising lumber costs
Rising materials costs and supply shortages threaten economic recovery, housing starts.
Codes and Standards | Mar 16, 2021
Massachusetts bill would mandate rooftop solar on new homes, commercial buildings
Proposed Bay State mandate modeled on California’s.
Codes and Standards | Mar 15, 2021
Nevada may create areas for tech companies to form own governments
Legislation calls for ‘Innovation Zones’ that could become smart cities.
Codes and Standards | Mar 11, 2021
Los Angeles commits to carbon-free city buildings
City will take into account embedded carbon when contracting to buy construction products.
Codes and Standards | Mar 10, 2021
‘Smart retrofitting’ will be crucial to net zero aspirations
AI, analytical software, Internet of Things are keys to decarbonization of built environment.
Codes and Standards | Mar 9, 2021
Salt Lake City is first jurisdiction to adopt new standards for off-site construction
Code Council and Modular Building Institute developing standards and compliance protocols.
Codes and Standards | Mar 8, 2021
Hyperlocal zoning could spur more affordable housing construction
Letting blocks and streets pass their own rules could have impact.
