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 | Mar 5, 2015
AEC industry groups look to harmonize green building standards, codes
The USGBC, ASHRAE, ICC, IES, and AIA are collaborating on a single green code.
Codes and Standards | Mar 2, 2015
Nevada moves to suspend prevailing wage rules on school projects
The Nevada Senate approved a bill that would suspend prevailing wage rules on school projects.
Codes and Standards | Mar 2, 2015
Proposed energy standard for data centers, telecom buildings open for public comment
The intent of ASHRAE Standard 90.4P is to create a performance-based approach that would be more flexible and accommodating of innovative change.
Codes and Standards | Feb 22, 2015
Louisiana officials critical of stricter building standards in flood-prone areas
Buildings would have to be built either two or three feet above the base flood elevation for a 100-year flood or above the base elevation for a 500-year flood.
Codes and Standards | Feb 18, 2015
Buildings with rocking steel-braced frames are advantageous in earthquakes
Research at Case Western Reserve University has found that buildings that rock during an earthquake and return to plumb would withstand seismic shaking better than structural designs commonly used today in vulnerable zones of California and elsewhere.
Codes and Standards | Feb 18, 2015
USGBC concerned about developers using LEED registration in marketing
LEED administrators are concerned about a small group of developers or project owners who tout their projects as “LEED pre-certified” and then fail to follow through with certification.
Codes and Standards | Feb 12, 2015
ASHRAE, USGBC, IES consider biomass requirements in green building standard
The proposal would add biomass to approved renewables.
Codes and Standards | Feb 12, 2015
New Appraisal Institute form aids in analysis of green commercial building features
The Institute’s Commercial Green and Energy Efficient Addendum offers a communication tool that lenders can use as part of the scope of work.
Codes and Standards | Feb 8, 2015
ASHRAE, IAQA approve consolidation
Under the consolidation, IAQA will become a part of the ASHRAE organization while maintaining its own brand and Board of Directors.
Codes and Standards | Feb 6, 2015
Obama executive order requires federal construction projects to consider flood damage caused by climate change
To meet the new standard, builders must build two feet above the currently projected elevation for 100-year floods for most projects.
