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 | Apr 23, 2020
Group will create ecosystem for smart building data
Seven Finnish companies aim to integrate all technical systems into a single platform.
Codes and Standards | Apr 23, 2020
COVID-19 epidemic demonstrates value of flexible hospital space
Some rooms being repurposed for ICU care.
Codes and Standards | Apr 15, 2020
Embodied carbon footprint can be reduced by using conventional materials
High-SCM concrete, and cellulose and wood fiber insulation among the greener alternatives.
Coronavirus | Apr 13, 2020
COVID-19 alert: City conducts a 'virtual building inspection' to allow Starbucks and bank to open
Bothell, Wash., issues a certificate of occupancy to developer after inspecting the property online.
Codes and Standards | Apr 13, 2020
Design competition focuses on reducing urban heat island effect
Cool Abu Dhabi aims to transform urban life in the Middle East.
Codes and Standards | Apr 13, 2020
What building science says about reducing COVID-19 transmission
Impact of temperature and relative humidity is unclear.
Codes and Standards | Apr 9, 2020
Owners retrofitting properties, monitoring performance during epidemic
Covid-19 outbreak may lead employers to reevaluate office commitments.
Codes and Standards | Apr 7, 2020
Dept. of Labor publishes guidance on paid sick leave, expanded family and medical leave
Includes fact sheets for employees, employers, and a questions and answers document.
Codes and Standards | Apr 1, 2020
Standards and codes meetings halted, postponed
ASTM International cancels in-person standards meetings; DOE’s National Energy Codes Conference postponed.
Codes and Standards | Mar 26, 2020
Ransomware attack on Canadian contractor underscores need for cybersecurity
Victimized company Bird Construction has defense, law enforcement contracts.
