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 | Jun 18, 2015
Guides to wood construction in high wind areas updated
The guides establish prescriptive, wind-resistive structural requirements for wood-frame buildings of different sizes and shapes.
Codes and Standards | Jun 18, 2015
New document addresses school safety and security
In an effort to balance security and fire safety features within codes, standards and planning, NFPA hosted a two-day workshop, “School Safety, Codes and Security”, last December. The findings are now available in an NFPA report.
Codes and Standards | Jun 18, 2015
Two myths regarding NFPA 101 Life Safety Code debunked
NFPA life safety engineer Ron Coté settles the debate over second egress doors and exit signs.
Codes and Standards | Jun 18, 2015
How to prevent corrosion in sprinkler system piping
The technical committees responsible for NFPA 13, Installation of Sprinkler Systems, have been looking at ways to eliminate or reduce corrosion in sprinkler systems for several revision cycles.
Codes and Standards | Jun 11, 2015
Steel Framing Alliance updates ‘Thermal Design and Code Compliance for Cold-Formed Steel Walls’ design guide
Includes results of new tests and addresses IECC and ASHRAE compliance paths.
Codes and Standards | Jun 11, 2015
Helena, Mont., may charge commercial developers a fee to fund public art
The fee would apply to new construction or alteration of nonresidential buildings of at least 20,000 sf.
Codes and Standards | Jun 11, 2015
DBIA releases new document on choosing a project delivery method
Provides owners and others with factors to consider when choosing the best method of delivery for their project.
High-rise Construction | Jun 5, 2015
Japanese policymakers discuss mandate for toilets in elevators
This quirky-sounding building code is a safety measure for the earthquake-prone nation.
Codes and Standards | Jun 4, 2015
OSHA publishes guide to restroom access for transgender workers
The guide advises employers to allow employees to use restrooms that correspond to their gender identity.
Codes and Standards | Jun 4, 2015
Guide helps Building Teams maximize team integration
The guide includes forms to support a two- to four-hour workshop to help an owner select the most appropriate delivery strategy.
