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
| Aug 27, 2014
Napa Valley assesses impact of structural retrofits on buildings after earthquake
About 30 inspection teams of two inspectors each have conducted at least quick exterior inspections of downtown Napa, Calif., buildings since a magnitude 6.0 earthquake struck the region.
| Aug 27, 2014
Liberty Building Forensics cautions hotel building teams on moisture, mold issues
Liberty Building Forensics Group, a building forensics firm warned building teams working on hotel projects to be on guard against moisture intrusion and mold.
| Aug 27, 2014
Requirement for site safety inspectors hampering construction in New York City
New York City’s regulation that requires contractors to hire independent safety inspectors for job sites is holding up projects worth millions of dollars, contractors say.
| Aug 27, 2014
Turkish government orders demolition of residential towers in Istanbul
Citing negative effects to a world heritage site, the Turkish central government has ruled that the recently completed OnaltiDokuz Residence towers must be demolished.
| Aug 21, 2014
Industry groups agree to streamline green building tool coordination and development
Major building industry groups the International Code Council (ICC), ASHRAE, the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), and the U.S. Green Building Council (USGBC) have agreed to collaborate on the development of Standard 189.1, the International Green Construction Code (IgCC), and the LEED green building program.
| Aug 21, 2014
Performance-based zoning: U.S. cities starting to loosen zoning regulations
Driven by New Urbanism, more than two dozen communities in the U.S. have loosened zoning restrictions in recent years.
| Aug 21, 2014
Meeting to finalize amendments to green property underwriting standard
The National Public Meeting for Resiliency + Infrastructure Consensus Underwriting Standard Amendments will take place September 16, from 9 a.m.-12p.m. at Perkins+Will, 1250 24th St. NW, Washington, DC in the World Wildlife Fund Building.
| Aug 21, 2014
American Iron and Steel Institute revises 14 test standards
The American Iron and Steel Institute (AISI) published 14 revised test standards in its S900-series.
| Aug 14, 2014
Mississippi county rejects adoption of state building code
The county board of supervisors voted unanimously to opt out of the state building code.
| Aug 14, 2014
Boards at odds over North Carolina county’s CM-at-Risk policy
Some local small contractors are not pleased with the school board’s CM-at-Risk policy that was instituted in 2007. The county’s board of commissioners has offered a sympathetic ear to their complaints