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 | May 8, 2018
Powerhouse coalition builds energy positive buildings
The goal: build buildings that provide more power than they cost to build, run, and demolish.
Codes and Standards | May 7, 2018
Plan advances in Los Angeles for Climate Emergency Mobilization Department
Would oversee efforts to reduce greenhouse gas emissions across the city.
Codes and Standards | May 3, 2018
Data collection, machine learning boost building efficiency
Sensors, software algorithms squeeze out waste.
Codes and Standards | May 2, 2018
Energy Department releases Updated EnergyPlus and OpenStudio building energy modeling tools
The tools can now accept input in epJSON format.
Codes and Standards | May 1, 2018
ASHRAE publishes new energy simulation-aided design standard
Requires building energy modeling during schematic design.
Codes and Standards | Apr 30, 2018
CALGreen projects pre-approved for streamlined LEED v4 requirements
Reduces need to run additional energy models.
Codes and Standards | Apr 26, 2018
New standard supports community resilience
ASTM International guidance supports cost-effective ways to withstand and recover from disasters.
Codes and Standards | Apr 25, 2018
Lessons learned from decades of Superfund cleanups guide contaminated land reuse
Sites repurposed for residential, commercial use, and solar energy generation.
Codes and Standards | Apr 24, 2018
Vibrant downtown core the key for urban multifamily development
Nighttime activity makes the difference.
Codes and Standards | Apr 19, 2018
ILFI launches new Zero Carbon Certification
Offers greater flexibility around project fuel types and offsetting renewables.
