Saturday, March 26, 2011

Seismic spectra and building response

Seismic waves can be analyzed for their characteristic periodicities. Longer period components will have more effect on taller buildings, while shorter periodicities will have greater impact on shorter buildings. This phenomenon was recognized in the 1986 Mexico earthquake. This phenomenon is nicely explained in a web page from MCEER, the Multidisciplinary Center for Earthquake Engineering.

There are some interesting links to Japanese data on the Tohoku earthquake from Tolyo University. One is: 

The comparison of long-period ground motion: The feature of seismic ground motion in city center and influence by architectural structure (By:Dr.Furumura and Dr.Takemura)
A velocity response spectrum is calculated according to waveform recorded at Earthquake Research Institute in Bunkyou-ku district. The figure shows comparison with that of Niigata Chuetsu earthquake in 2004. The Chuetsu earthquake had strong long-period ground motion with period of 7 second, which causes only a minor damage mainly among skyscraper buildings. The 2011 Tohoku earthquake has about the same strength of velocity response occurred in a wide periodic band from 0.5 to 20 second. Not only skyscrapers but also all kind of buildings from wooden building (below 0.5 second) to a low-slung building (around 1second) and skyscraper buildings (few second).

3 comments:

  1. hmm... i don't really understand these. but i think i'm interested in it. can you explain it to me with more simpler words, please? i'm still a junior undergraduate.

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  2. Go to this link for more details:
    http://mceer.buffalo.edu/infoservice/reference_services/EQaffectBuilding.asp

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  3. Its obviosly... Its so simple, that i cant uderstand who needs this diagram.. Stupid...

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