The Los Angeles County Board of Supervisors took a first step on Tuesday, Feb. 28, toward requiring the retrofit of older, so-called “non-ductile concrete” high rises that are at higher risk of collapse during a powerful earthquake.
The board voted unanimously to direct its public works staff and attorneys to draft an update to the county building code that would require retrofitting of all such buildings within 10 years that are either located in unincorporated areas or owned by the county. The code would also require that owners of impacted buildings submit structural evaluation reports within three years, and plans to retrofit or demolish the buildings within five years.
“While the county building standards have been updated to ensure new construction can withstand seismic activity, the most vulnerable buildings are non-ductile concrete high rises, which are prone to brittle behavior during an earthquake,” according to the motion by Supervisors Holly Mitchell and Hilda Solis.
“These buildings which were constructed prior to 1976 when California adopted the 1976 uniform building code were constructed with a limited amount of reinforcing steel at the columns, joints and walls of these structures, which make them particularly vulnerable to damage and collapse.”
The motion also called on county staff to review possible development of financial assistance programs that could help property owners cover the costs of such retrofit projects. It also called on county staff to conduct an inventory of “soft-story” buildings in unincorporated areas that could also be more likely to collapse in a strong quake.