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 | Oct 6, 2016
New York City files criminal charges on owner for deadly building façade accident
The owner allegedly did not heed warning about danger of the crumbling exterior.
Codes and Standards | Oct 5, 2016
New York becomes the first city to adopt a target for energy storage
Mayor de Blasio also announces increased solar generation goals
Codes and Standards | Oct 4, 2016
New global residential floor space measurement standard unveiled
The new standards will produce better transparency and are said to benefit investors.
Codes and Standards | Sep 29, 2016
Dept. of Energy forecasts big jump in LED use, resulting energy savings
Big gains are expected in both commercial and residential markets.
Codes and Standards | Sep 28, 2016
San Francisco commercial, multifamily regulations aim to reduce traffic volume
City planners will require design features to cut miles driven.
Codes and Standards | Sep 28, 2016
Society of Landscape Architects releases guide to resilient design
The goal is to retrofit communities to better withstand extreme weather events.
Codes and Standards | Sep 26, 2016
Washington State Energy Code updates include dedicated outdoor air system requirements
The updates will change design approach to HVAC.
Codes and Standards | Sep 22, 2016
Construction firms pulling back from federal market due to new reporting rules
‘Subjective, very vague’ policies are said to create too much risk.
Codes and Standards | Sep 21, 2016
Airbnb presents legal liability for multifamily owners
How building owners can reduce risks.
Codes and Standards | Sep 21, 2016
Healthy buildings becoming a key design priority for both architects and building owners
Nationwide survey finds nearly three of four architects cite health impacts influencing design decisions
