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 10, 2017
New guidelines for quality control on application of membrane roof systems released
NRCA document provides guidance for on-site evaluation.
Codes and Standards | Oct 9, 2017
New app calculates maximum allowable heights for building occupancy types, classes of construction
The app streamlines compliance on various types of construction.
Codes and Standards | Oct 5, 2017
California lawmakers pass bill that requires GCs to pay wages of sub employees if subs fail to pay
The measure will go into effect in January if the governor signs it.
Codes and Standards | Oct 4, 2017
Ambitious but realistic increase in clean energy would cut GHG emissions by 80% in the U.S.
NRDC report says goal can be achieved with existing tools.
Codes and Standards | Oct 3, 2017
Reducing duct leakage is focus on latest green building standards updates
ASHRAE 189.1 broadens testing requirements to include more types of ducts.
Codes and Standards | Oct 2, 2017
Nationwide retrofit strategy in Canada could cut 51% of emissions from large buildings
The roadmap provides government and industry with a targeted plan.
Codes and Standards | Sep 28, 2017
Resources available for new OSHA respirable crystalline silica regulation
NRCA offers compliance tools for contractors.
Codes and Standards | Sep 28, 2017
New tool compares HVAC system efficiency
IAPMO and Hydronics Industry Alliance unveil BEST to evaluate systems in early design phase.
Codes and Standards | Sep 26, 2017
Anti-drone technology can ward off unauthorized drone flights
The technology can be used to prevent terrorist attacks and spying.
Codes and Standards | Sep 25, 2017
How-to guide to renovating shopping centers available
E.U. research project focuses on energy efficiency and occupant comfort.
