By Daniel Larios
Staff Writer

May 23, 2014 – When the 1994 Northridge earthquake battered Santa Monica, it damaged some 1,600 housing units. Two decades later, City officials are looking to identify the remaining buildings that could be vulnerable when the next big temblor hits.

Tuesday night, the City Council will consider hiring the nation’s oldest and largest earthquake engineering firm to identify buildings that are potentially hazardous during and after an earthquake, said Ron Takiguchi, the City’s building officer.

Established in 1940, the Los Angeles-based Degenkolb Engineers is expected to advise staff on retrofit techniques and respective retrofit costs, officials said.

“The City of Santa Monica has many buildings that pre-date 1996 which may require seismic retrofit.” Takiguchi wrote in his report to Council.

“Although some of these buildings have been identified and retrofitted to acceptable engineering standards, we believe that there are many buildings that remain un-retrofitted and may present a hazard to public safety.”

Several methods can be used to identify vulnerable buildings, which City officials estimate can number as few as some 150 and as many as about 500, Takiguchi said.

“One is looking at records from our permit database and from the LA County Assessor’s office, identifying those built before 1996,” Takiguchi told the Lookout. 

“Another is visual evidence of being a non-ductile concrete building, which is one of the types that need retrofitting.  They would have a certain look and construction method and would be easy to identify.”

“There are very few, if any, single family homes that are non-ductile concrete, so we would use commercial zoning maps,” he added.

There are several steps involved in the seismic retrofitting of a building, Takiguchi said.

“First is (to) identify the part of the building that needs to be strengthened. Then, find out how they can be strengthened.  And finally, just executing that plan,” he said.

“Basically. It’s analysis, design, method and execution,” he added.

Santa Monica’s older buildings fall into five major categories –un-reinforced masonry, concrete wall tilt-up, weak open front soft story, non-ductile concrete and steel moment frame buildings, according to the staff report.

“Despite the best efforts of staff and building owners to retrofit buildings that fall into the five categories, there are still some that are not,” the staff report reads.  “The exact number is not known, but it’s estimated to be between 30 and 100 of each.”

According to media reports, the cities of Los Angeles and Santa Monica in the last decade have approved more than a dozen construction projects on or near two well-known faults without requiring seismic studies to determine if the buildings could be destroyed in an earthquake.

A recent spate of earthquakes has resulted in only minimal damage to Santa Monica buildings.  However, the new seismic retrofit program is designed to prepare building owners and residents for “The Big One,” which could be more powerful than the 1994 6.7 magnitude Northridge earthquake.

The earthquake destroyed approximately 1,600 apartments, roughly 5 percent of the city's total housing stock. The earthquake caused $70 million in damages, according to a 2004 report by the California Policy Research Center.

Landmark buildings, including St. Monica Catholic Church and the 16-story concrete Champagne Towers on Ocean Avenue, were also badly damaged. The Sea Castle apartment building had to be torn down. The collapse of parts of Interstate 10 made Santa Monica hard to access for rescue workers.

The structure of the adjacent Santa Monica Mountains focused the Northridge earthquake’s seismic energy on the city by the sea like a lens, said Dr. Thomas Jordan, director of the Southern California Earthquake Center at USC.

In the aftermath, Santa Monica decided to start by identifying potentially vulnerable buildings, and then demand that owners retrofit them. The original ordinance was passed soon after the 1994 Northridge earthquake, but officials added more detail in the ensuing years.

Santa Monica initially identified about 70 potentially vulnerable concrete buildings, with one in three used for residential purposes, according to city reports.

But the city never mailed notices to owners alerting them of the city's findings, according to a Los Angeles Times reports.

Some property owners retrofitted their buildings, but others did not. Also, the City’s older seismic standards were not as strict as those adopted in the late 1990s, according to the LA Times.

The city now enforces the law only when owners remodel and apply for construction permits. A 2005 City document estimated that 1,500 buildings of all types would require mandatory seismic retrofit.

To learn more about how to be prepared in the event of an earthquake, visit City Hall’s Office of Emergency Management at www.smgov.net. It’s recommended that residents have enough food and water to last for up to seven days.

An emergency preparedness kit should include food, water, bedding, medications, pet preparedness materials and other items you rely on, officials said.

It is also recommended to sign up for SM Alerts, a notification system to keep people informed during an emergency. Visit www.smalerts.net and sign up today.