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 10, 2012
Chapter 6 Energy Codes + Reconstructed Buildings: 2012 and Beyond
Our experts analyze the next generation of energy and green building codes and how they impact reconstruction.
| May 10, 2012
Resilience should be considered a sustainability factor
Since a sustainable building is one you don't have to rebuild, some building sustainability experts believe adding points for "resilience" to storms and earthquakes to the LEED sustainability rating tool makes sense.
| May 10, 2012
University of Michigan research project pushes envelope on green design
A research project underway at the University of Michigan will test the potential of intelligent building envelopes that are capable of monitoring weather, daylight, and occupant use to manage heating, cooling, and lighting.
| May 10, 2012
Fire suppression agents go greener
Environmental sensitivity is helping to drive adoption of new fire suppression agents.
| May 10, 2012
Industry groups urge Congress to leave contracting decisions to agencies
An organization of several industry groups urged Congress to leave many contracting decisions to the discretion of individual agencies by avoiding blanket mandates.
| May 10, 2012
OSHA proposes new rule to have employers find and fix hazards
The Occupational Safety and Health Administration has proposed a new regulation, Injury and Illness Prevention Program, or I2P2, which would compel employers to find and fix safety hazards.
| May 3, 2012
Stay current on green codes at AGC Environmental Conference
Keep abreast of market trends such as 2012 changes to green standards and codes at the AGC Contractors Environmental Conference, June 7-8, 2012 in Arlington, Va.
| May 3, 2012
OSHA reduces fines in Cincinnati casino collapse
The Occupational Safety and Health Administration has reduced the number of violations from four to two against four firms it cited earlier this month in the collapse of a casino under construction in Cincinnati.
| May 3, 2012
New York City implements controversial crane licensing requirements
New York City officials announced strict new licensing and testing requirements for all crane operators in New York City to raise safety standards.
