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 | Jan 31, 2020
Colorado ranks first in LEED Top 10 states
Rankings of states for LEED certified square feet per person released.
Codes and Standards | Jan 30, 2020
Dramatic demographic shifts poised to alter global workplace
By 2030, Millennials and Generation Z will dominate workforce.
Codes and Standards | Jan 29, 2020
Half of Manhattan’s new residential skyscrapers are empty
Excess comes as middle class housing shortage worsens.
Codes and Standards | Jan 28, 2020
Updated Engineered Wood Construction Guide now available
Provides guidance on building engineered wood floors, walls, and roofs.
Codes and Standards | Jan 24, 2020
Fenestration Rating Council earns ANSI certification
FenStar Certification Program ensures windows, doors, and skylights meet Energy Star specifications.
Codes and Standards | Jan 23, 2020
Rent control policies backfire on goal of boosting affordable housing
Natl. Apartment Assn. study says rent control decreases housing supply, harms condition of housing stock.
Codes and Standards | Jan 22, 2020
Potential energy savings from smart meters is largely unrealized
Most utilities underuse the technology that can help customers save money.
Codes and Standards | Jan 21, 2020
Contractors pay practices reviewed in new database
Fastest and slowest paying GCs revealed.
Codes and Standards | Jan 17, 2020
Several states with ambitious climate goals will have to restrict natural gas as a fuel
Buildings would have to heat and cook with electricity.
Codes and Standards | Jan 16, 2020
New solar-ready mandate affects commercial and residential buildings in St. Louis
All new buildings must have reserved rooftop sections for PVs.
