Critical Equivalent Wind Speeds for Overturning and Roof Blow-off of 2-StoryWooden Houses
Rei Okada*, Yukio Tamura**, Masahiro Matsui**,
and Akihito Yoshida**
*Wind Engineering Research Center, Tokyo Polytechnic University, 1583, Iiyama, Atsugi, Kanagawa 243-0297, Japan
**Department of Architecture, Tokyo Polytechnic University, 1583, Iiyama, Atsugi, Kanagawa 243-0297, Japan
4 tornadoes occurred on May 6th, 2012 in the north part of the Kanto area, Japan. Of these, the one that struck Joso city and Tsukuba city in Ibaraki prefecture was the strongest. According to the JapanMeteorological Agency, it was 0.5 km wide, 17 km long, and Fujita scale level 3 . According to local government statistics from Ibaraki prefecture, 1 person was killed, 39 were injured, and 1,133 structures were damaged – 207 destroyed, 258 half destroyed, and 668 damaged . The Wind Engineering Research Center of Tokyo Polytechnic University carried out field investigations in damaged areas onMay 7, 8, 9, and 13. Based on its results, Fujita scale strength was estimated at 4. Based on our damage investigation results, we deduce scenarios and estimate wind speed when the 2 structures this paper focuses on were catastrophically damaged.
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-  Japan Housing and Wood Technology Center, “Allowable Stress Design Method of Conventional Post and Beam Structure,” 2008 (in Japanese).
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