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
| Nov 26, 2012
Minnesota law to spur development, job creation produced few jobs
Legislation that allowed local governments to direct excess property tax dollars from tax-increment financing districts into other private developments was supposed to kick-start construction hiring in Minnesota.
| Nov 26, 2012
How to boost resilient systems that are sustainable
Cities of the future can be both more resilient and more sustainable by promoting strategies that include solar power and green roofs, programs that minimize demand for energy, rain gardens, and permeable pavement.
| Nov 26, 2012
Developer of nation’s first LEED platinum skyscraper focuses on carbon reduction
The Durst Organization, the developer of the first LEED platinum certified skyscraper in the country, says it will not seek LEED certification for its residential pyramid planned for New York’s West 57th Street.
| Nov 26, 2012
Questions linger over ability of Miami's newer high-rises to withstand hurricanes
Some towers in Miami, rebuilt after a hurricane in 2005, were allowed to be constructed under older building codes instead of newer ones created after Hurricane Wilma.
| Nov 26, 2012
Changes in development and building standards needed for health of Potomac River
The Potomac River’s health stands to suffer if the region does not change its development and building standards, according to the Potomac Conservancy.
| Nov 16, 2012
South Dakota prefers LEED over building code on state projects
“(LEED is) much better than a mandatory building code because you get a little wiggle room in these projects,” said Mike Mueller, a spokesman for the South Dakota Bureau of Administration.
| Nov 16, 2012
AAMA publishes quality assurance guidelines for Polyamide Thermal Barriers
The American Architectural Manufacturers Association (AAMA) has published QAG-2-12, Voluntary Quality Assurance Processing Guide for Polyamide Thermal Barriers.
