A ‘new frontier’ launched for earthquake safety
Earthquakes are not selective about where and when they strike, and they are equally as indiscriminate on the types of buildings they can rattle to the ground. While it is true that some structures may be more prone to damage than others, the reality is that virtually all buildings have the capacity to fail in a major quake.
Recognizing that, many cities throughout the state are kicking off new laws requiring retrofits of various types of buildings – a phenomenon the Los Angeles Times recently proclaimed as the start of a “new frontier” for earthquake safety.
The city of Santa Monica this week took the lead on what is becoming a new wave of more comprehensive laws to cover not only soft-story and non-ductile buildings, but others as well.
Santa Monica’s law, adopted on Tuesday, is much more thorough than the ordinance enacted in 2015 by the city of L.A. and the 2013 law adopted by San Francisco. Even more notable is the fact that there are untold numbers of cities poised to do the same. It’s only a matter of time.
A new trend in public safety
Famed seismologist Dr. Lucy Jones told the Times it is remarkable to see how the political winds have changed for elected officials considering seismic-retrofit laws.
“There are dozens of cities curious at looking at this,” she said. “People are starting to recognize how necessary this is.”
The city of Los Angeles’ retrofit law, which took effect last year, requires the stabilization of some 15,000 pre-1978 wood-frame, soft-story buildings and non-ductile concrete buildings. Soft-story structures have parking or open space on the ground floor, and apartment or office units built above. Non-ductile buildings are pre-1977 concrete structures with a roof and/or floor supported by a concrete wall or concrete column. A couple of years earlier, San Francisco adopted a similar law affecting some 2,800 buildings that are home to 58,000 people and 2,000 businesses.
San Francisco officials, at the time the law was passed, estimated that up to 85 percent of those soft-story buildings would fail and be tagged as “unsafe” following a magnitude 7.2 quake. Berkeley and other Bay Area cities adopted similar ordinances about the same time.
Raising the bar on safety
- Santa Monica’s ordinance applies to not one or two, but five different building types:
- Unreinforced masonry built before 1975
- Concrete tilt-up built before 1994
- Soft-story built before 1978
- Non-ductile concrete built before 1977
- Steel moment frame built before 1996
These buildings must all be retrofitted in two to 20 years, depending on the type of structure. Single-family homes are also strongly encouraged to undergo retrofits, but that is strictly voluntary at this time.
“There is no greater responsibility of government than public safety,” Building and Safety Director David Martin said in his report to the City Council. “… Although Santa Monica adopted mandatory Seismic Retrofit standards in 1991, many buildings continue to be at risk and it is necessary to update these standards and establish a program to ensure compliance.”
The city went so far as to design a map that showed all geological faults in the city and identified structures on the map that may require retrofits under the new law.
It may be just a matter of time before your city does the same.
Tagged: Seismic Retrofitting