| Project/Area Number |
14350302
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | Kyoto University |
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Principal Investigator |
KAWAI Hiromasa KYOTO UNIVERSITY, Disaster Prevention Research Institute, Professor, 防災研究所, 教授 (60027282)
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| Co-Investigator(Kenkyū-buntansha) |
MARUYAMA Takashi KYOTO UNIVERSITY, Disaster Prevention Research Institute, Associates Professor, 防災研究所, 助教授 (00190570)
ARAKI Tokihiko KYOTO UNIVERSITY, Disaster Prevention Research Institute, Assistant Professor, 防災研究所, 助手 (60335221)
HAYASHI Taiichi KYOTO UNIVERSITY, Disaster Prevention Research Institute, Associates Professor, 防災研究所, 助教授 (10111981)
OKUDA Yasuo KYOTO UNIVERSITY, Building Research Institute, Senior Researcher, 構造研究グループ, 上席研究員 (70201994)
NISHIMURA Hiroaki General Building Research Corporation, Senior Researcher, 耐風試験室, 室長
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 2004: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2003: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 2002: ¥7,700,000 (Direct Cost: ¥7,700,000)
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| Keywords | Wind induced damage / Natural wind / Field experiment / Local pressure / Averaging time / Roof tile / Internal pressure / Topological effect / 強風被害 / 風荷重 / 風洞実験 / 局部風圧 / 屋根葺き材 / 地形 / 車載型ドップラレーダ / 葺き材 / ダブルスキン / 非定常 / 高層建築物 / 非定常流 |
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| Research Abstract |
The aim of the research project is to find a rational wind resistant design measure for a reduction of damage of buildings and their claddings induced by strong winds. The several investigations were carried out for the project.
The first research is to investigate characteristics of wind induced pressure fluctuation on a tall buildings in natural winds. It is often pointed that most of severe damages of claddings in typhoon winds were caused by a strong gust, of which characteristics is very non-stationary and can not be simulated in a wind tunnel. A large scale tall building model was set in the field in Shionomisaki Wind Effect Laboratory of Kyoto University and pressure fluctuations on walls were measured both in seasonal strong winds and typhoon winds. The analysis shows that the pressure coefficient should be evaluated in a proper time scale related with formation of a pattern of flow around the building instead of the ordinary 10 minute averaging period used in the analysis of a
… More
meteorological record. This short time pressure can be used for the evaluation of the peak wind loads combined with the non stationary wind data like in a typhoon wind, which can be obtained in wind tunnel experiment in the same time scale.
The second research is related with the scattering of the roof tiles in strong wind. More than 80% of wind induced damages occurs at roofs. Particularly, the roof tiles can be easily scatted by strong winds. Pressures on a surface of a roof tile and in a batten space back of the tile were measured in natural winds, using an experimental house set in the field of the laboratory. The maximum peak lift force on the tile induced when wind attacks normal to the root, because of the large unbalance of pressures on the outside and the inside of the tile. On the other hands, the lift forces of the tile on the side and leeward roofs were not so large even when the large local peak suction acted on the surface of the tiles, because the large peak suction balanced to the back pressure of the tile. This findings agrees well with reports of damage observation by strong wind in which many tiles on the windward roof were scatted in strong winds.
The third investigation is observations of damages by strong wind in typhoons. A large roof was blown off from a building and hanged on the overhead wire of New Tokaidou Line and Sinkansen stopped for 7 hours. The roof was a repaired roof covered on the old roof. It can be noticed that the type of the risk and the loss is fairly high. The cause of the blown off was investment in details. The other type of damage is the scattering of the long steel panel on the roof. This type of the damage is related with the internal pressure back the panel and the fatigue of the fixed volt. The historical structure were again suffered severe damages by typhoon wind, particularly the down flow from the valley. This type of the strong down flow were often observed in typhoons, and causes severe damage. One of the cause is a topological effect, which is convinced by the numerical simulation. Less
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