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 | Jul 8, 2020
Standards for reducing risk of COVID-19 in senior living communities
AIA releases strategies and illustrations for the sector.
Codes and Standards | Jul 6, 2020
Guide presents benefits of public-private partnerships
Discusses process from project conception to construction.
Codes and Standards | Jul 1, 2020
COVID-19 public health guidelines may be downplaying building systems solutions
Emphasis on cleaning surfaces overlooks importance of mechanical infrastructure.
Codes and Standards | Jun 30, 2020
WELL building institute steps up health safety rating for hotels and resorts
Certification body forms advisory group of industry leaders and health experts.
Codes and Standards | Jun 30, 2020
7 must reads for the AEC industry today: June 30, 2020
Affordable housing comes to the Bay Area and this is not the end of cities.
Codes and Standards | Jun 29, 2020
Mandated building retrofits are necessary to meet climate crisis
Performance standards could greatly reduce GHG emissions.
Codes and Standards | Jun 29, 2020
New buildings can fall short of designed performance
Similar structures can produce different energy usage results.
Codes and Standards | Jun 25, 2020
Arc offers tools, analytics for safe workplace re-entry
Platform helps sustainability teams to collect data, benchmark progress, measure impact, and improve performance.
Codes and Standards | Jun 24, 2020
New API enables design and construction technology platforms to connect
Construction Specifications Institute offers “digital classification engine.”
Codes and Standards | Jun 23, 2020
State lawmakers encouraging transition to heat pumps for building heating
Policies aim to replace gas heaters with electric units.
