- Los Angeles Mayor Eric Garcetti has proposed a program of mandatory retrofits to make steel buildings, daycare centers and private schools more resilient to earthquakes, according to the Los Angeles Times. The program would also include buildings that contain private schools and daycare centers, not typically regulated for earthquake safety like public schools.
- The recommendations come after the city's recently published Resilient Los Angeles report said steel buildings constructed from the early 1970s through 1994 were susceptible to earthquake damage because of welding techniques, the inspection process, the filler metal used in the welds and the configuration of the connection between vertical columns and horizontal beams.
- According to a U.S. Geological Survey study, there are five steel buildings in Southern California that could collapse in a major earthquake, potentially causing hundreds of deaths and injuries. The Resilient Los Angeles report also advocates for stronger minimum earthquake standards for all new construction.
Earthquakes are inevitable in Southern California, but stricter building codes and new resilient construction methods can help prevent deaths and injuries and minimize damage to structures.
Los Angeles has a retrofit program underway that requires some brick, concrete and wood structures be shored up to protect them from the effects of seismic activity. There are approximately 13,500 wood buildings and 1,500 concrete or masonry structures that fall under the new program, and officials estimate the total cost of the work will range from $60,000 to millions.
The Los Angeles Department of Building and Safety began sending preliminary notices to the affected property owners in November in an effort to make them aware of their obligations under the new regulations. About 3,000 property owners have started to retrofit their buildings, and 300 have completed the necessary work. Others have sold their buildings in order to avoid the expense.
California hospitals also must retrofit their facilities to meet new state seismic regulations, and some of begun that work. Scripps Health last year announced a $2.6 billion construction program that includes the required retrofitting.
For new construction, building techniques and materials are being developed that are resulting in stronger buildings. For example, construction is underway in Seattle on the first skyscraper to feature a rebar-free concrete core. The cross-tied plates in the coupled steel-plate composite shear wall will be filled with concrete in order to increase earthquake resistance. The $370 million structure also will be more resistant to lateral wind loads, according to Engineering News-Record.