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 | Sep 7, 2017
More than half of Houston properties at high or moderate risk of flooding are not in FEMA flood zone
Properties outside of these zones are not required to carry flood insurance.
Codes and Standards | Sep 6, 2017
Seventy percent of contractors have trouble finding workers
AGC survey indicates that fewer companies may be able to bid on projects.
Codes and Standards | Sep 5, 2017
New CTBUH initiatives to investigate link between fire and façades
In wake of Grenfell tragedy, Council forms new workgroup.
Codes and Standards | Sep 1, 2017
U.S. markets with the largest hotel construction pipeline
New York has the largest hotel construction pipeline of any U.S. market.
Codes and Standards | Aug 30, 2017
Trump rescinds elevation requirements for federally funded buildings and infrastructure
Flood protection on subsidized housing, hospitals, and other public buildings rolled back.
Codes and Standards | Aug 30, 2017
Stormwater runoff mitigation pays off for some building owners
Rain gardens, green roofs, cisterns, and rainwater recycling add value.
Codes and Standards | Aug 28, 2017
Commercial properties address state carbon-reduction policies
EV charging stations, batteries, and microgrid technology are all part of effort to meet demand for cleaner power.
Codes and Standards | Aug 24, 2017
OSHA silica dust exposure enforcement begins Sept. 23
Vacuum dust collection, water-delivery systems, and respirators will be required.
Codes and Standards | Aug 18, 2017
Cool roofs may increase air pollution
California’s requirement for cool roofs on new non-residential buildings could promote smog.
Codes and Standards | Aug 17, 2017
Black market sales of OSHA training certifications plague New York City construction industry
Task force formed to get fake training cards off the streets and workers properly trained.
