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 | Feb 21, 2018
FEMA document provides simplified seismic design provisions for low-hazard regions
Forty four states have areas defined as low-hazard.
Codes and Standards | Feb 20, 2018
Federal budget includes disaster mitigation provisions
Bipartisan bill encourages states to adopt latest building codes.
Codes and Standards | Feb 19, 2018
Easy access to indoor environment controls yields improved efficiency and workplace productivity
JLL/Purdue University project is developing algorithms to improve indoor comfort.
Codes and Standards | Feb 14, 2018
After Energy Star stopped certifying medical properties, a REIT developed its own certification
Welltower uses internal system to evaluate total building performance.
Codes and Standards | Feb 13, 2018
Rezoning, innovative investor enabling development of a “metroburb” in New Jersey
Indoor mixed-use “Main Street” blossoms in giant former Bell Labs building.
Codes and Standards | Feb 12, 2018
Publication provides insight into managing risk of wind-borne debris damage
Explains how models and data are used to assess the risk of structural damage.
Codes and Standards | Feb 8, 2018
EPA’s Water of the U.S. rule delayed for two years while repeal sought
Controversial Obama-era regulation may never be implemented.
Codes and Standards | Feb 5, 2018
Astrophysicist turns his skills toward identifying and predicting location of vacant buildings
Project could help Baltimore and other cities redevelop blighted properties.
Codes and Standards | Feb 5, 2018
Denver’s new green roof mandate raises implementation policies
Voter initiative left many details undecided.
Codes and Standards | Feb 2, 2018
How workplace design can position financial services companies for success
HOK report examines forces reshaping industry.
