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
| Oct 25, 2012
Nashville providing incentives for green roofs
The city of Nashville, Tenn., is promoting the installation of green roofs through a measure providing a $10 reduction in a property's sewer fees for every square foot of vegetative roof.
| Oct 25, 2012
Net Zero buildings will use operating systems like computers to save energy
As buildings become more efficient and begin to use distributed electricity generation, they will need to become “smarter,” using operating systems much as a computer does.
| Oct 18, 2012
Princeton, N.J. residents upset over proposal to exempt colleges from land use laws
Princeton, N.J. residents criticized proposed legislation that would exempt private colleges and universities from following local land use laws for construction projects.
| Oct 18, 2012
Utah contracting firm challenges state immigration law
Universal Contracting LLC of American Fork, Utah, has filed suit challenging the constitutionality of Utah’s 2011 immigration law.
| Oct 18, 2012
More than 65,000 construction, design jobs may be cut if sequestration takes place
About $2 billion worth of construction and design projects would be eliminated if scheduled federal budget cuts, referred to as sequestration, take effect on Jan. 2, 2013.
| Oct 18, 2012
OSHA investigating parking garage collapse that kills four at Doral, Fla. college
OSHA is investigating the collapse of a five-story concrete parking garage under construction at Miami Dade College West Campus in Doral, Fla. that killed four workers and injured several others.
| Oct 18, 2012
EPA commercial building lead paint rule pushed back to 2015
The U.S. Environmental Protection Agency's inclusion of commercial buildings in a residential lead paint rule is being delayed until 2015.
| Oct 18, 2012
Chicago pushing green roofs to reduce heat island effect
The city of Chicago has mandated that all new buildings that require any public funds must be LEED certified, usually with a green roof.
