IRVINE : City Releases Report on Quake Readiness

The vast majority of city structures were built with seismic safety in mind and probably would fare well during a major temblor, city officials said in a report on earthquake readiness.

The report was prepared in the wake of the Northridge earthquake and was presented to the City Council last week.

City building inspectors did express concerns about the more than 200 “concrete tilt-up” warehouse structures that could experience substantial damage during a large quake.

Most of the “tilt-up” warehouses are in the Irvine Business Complex, a district of office towers, commercial buildings and industrial sites at the western edge of the city.

The concrete buildings can be retrofitted to resist a quake by bolting the walls, floors and ceilings together. Such retrofitting is required for warehouses that are converted into meeting rooms for churches and other groups. Retrofitting is voluntary for all other businesses. About 13 of the tilt-up structures have been retrofitted so far.

Irvine probably would sustain decidedly less damage during a major quake than did the San Fernando Valley because most of the city’s structures were built after 1974 and had to comply with strict quake building standards, City Manager Paul O. Brady Jr. said.

There are no non-reinforced masonry buildings in the city and very few older single-family homes that are not bolted to their foundations.

Most residential parts of Irvine have little susceptibility to liquefaction, according to data from the California Division of Mining and Geology. Some parts of the Irvine Business Complex have a slightly higher susceptibility, according to the data.