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
| May 22, 2014
Colorado approves $4.2B data center said to be invulnerable to power outages
The Niobrara Data Center Energy Park project in Colorado will be the first data center to be fully self-contained with its own self-generated energy production facility.
| May 22, 2014
Energy Department analysis shows efficiency gains from ASHRAE 2013 energy standard
Preliminary DOE analysis shows that the ASHRAE/IES’s 2013 energy efficiency standard contains energy savings over the 2010 standard of 8.5% source energy and 7.6% site energy.
| May 22, 2014
Federal disaster policy should focus on mitigation, insurance group says
Federal disaster policy should shift its focus toward mitigation in order to reduce future disaster costs, the National Association of Mutual Insurance Companies says.
| May 22, 2014
Study quantifies cost premiums for net zero buildings
The 73-page report breaks down the incremental cost premiums for transforming three LEED Platinum-designed buildings into net-zero energy, net-zero water, and living Buildings.
| May 22, 2014
Senate kills bipartisan energy efficiency bill over Keystone pipeline amendment
The legislation focused on energy efficiency standards such as water heaters with smart meters and cheaper heating and cooling systems for office buildings.
| May 19, 2014
Construction skilled-worker shortage causing rise in claims
The improved economy has boosted construction starts, but a shortage of experienced trade workers has led to more on-the-job injuries and construction defects.
| May 15, 2014
AISC Prequalified Seismic Moment Connection standard update now available
The AISC standard Prequalified Moment Connections for Special and Intermediate Steel Moment Frames for Seismic Applications (ANSI/AISC 358-10) has been updated with a second supplement, ANSI/AISC 358s2-14.
| May 15, 2014
ConsensusDocs releases new agreements for contractors who hire consultants
ConsensusDocs has released the new ConsensusDocs 746 Constructor & Geotechnical Consultant Agreement and the 747 Constructor & Consultant Agreement.
| May 8, 2014
Report: Top storm-resilient cities have high adaptive capacity
The most resilient cities in the world, including five in the U.S., have attributes that would enable them to recover better than others from devastating natural disasters.
| May 8, 2014
LED lighting helps cities receive Energy Star designation
Thanks largely to an ambitious program to boost the use of LED lighting in its buildings, Los Angeles is the top ranked U.S. city on the Environmental Protection Agency’s annual list of U.S. cities that are doing the most to improve energy efficiency.
