Seismic code
Seismic codes or earthquake codes are building codes designed to protect property and life in buildings in case of earthquakes. The need for such codes is reflected in the saying, "Earthquakes don't kill people—buildings do." Or in expanded version, “Earthquakes do not injure or kill people. Poorly built manmade structures injure and kill people.”[1]
Origin
While modern seismic code is heavily influenced by earthquakes in California and ensuing California legislation, the origins of seismic code go back to the 1700s in Portugal.
The 1755 Lisbon earthquake resulted in prescriptive rules for building certain kinds of buildings common in the area. Events in Messina, Italy (1911), and Kanto (Tokyo) Japan (1923) led to guidelines for engineers to design buildings for horizontal forces of about 10% of the weight of the building.
The 1906 San Francisco earthquake produced little or no code development, but the 1925 Santa Barbara earthquake convinced a critical mass of those in power in California of the need for seismic requirements. Two years later in 1927 the first seismic regulations appeared as a voluntary appendix in the 1927 Uniform Building Code.
Immediately after the 1933 Long Beach earthquake, careful analysis of structural failures in that quake by architect Louis John Gill formed the basis for much of the California seismic legislation (Field Act for schools and Riley Act for all buildings),[2] which are now used on many other places on the planet.[3]
Seismic code has been under constant evolution since 1927, with changes often instigated by earthquakes in California.
Around the world
Mexico
The first Mexico City building code was issued in 1942; since 1966, it contains a complete set of regulations for structural design and has served as a reference for municipalities across the country. In 1976, the code adopted a coherent format for all materials and structural systems, based on limit states design philosophy. In February 2004 a new set of seismic codes was issued.[4]
Spain
In Spain the seismic code is called the "Norma de Construcción Sismorresistente". (See the article in Spanish Wikipedia)
United States
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In the United States the Federal Emergency Management Agency (FEMA) publishes "Recommended Seismic Provisions for New Buildings and Other Structures".[5]
References
- ^ "Mitigation works: Earthquake" (PDF). Earthquake Engineering Research Institute. Retrieved 26 June 2014.
- ^ PEER (Pacific Earthquake Engineering Research Center at the University of California, Berkeley) Tall Buildings Initiative—Task 2 Workshop April 18, 2007
- ^ Rev. C. Douglas Kroll, Journal of San Diego History, "LOUIS JOHN GILL: Famous but Forgotten Architect", San Diego Historical Society Quarterly, Summer 1984, Volume 30, Number 3
- ^ "SEISMIC DESIGN AND CODES IN MEXICO", Mario ORDAZ and Roberto MELIZ, 13th World Conference on Earthquake Engineering Vancouver, B.C., Canada, August 1-6, 2004, Paper No. 4000
- ^ "NEHRP Recommended Seismic Provisions for New Buildings and Other Structures. 2009 Edition", Federal Emergency Management Agency