| Project/Area Number |
10556041
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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 | 展開研究 |
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| Research Field |
林産学
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| Research Institution | Akita Prefectural University (1999)
Akita Prefectural College of Agriculture (1998) |
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Principal Investigator |
SASAKI Takanobu Institute of Wood Technology, Akita Prefectual Univ., Research Associate, 木材高度加工研究所, 助手 (00279514)
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| Co-Investigator(Kenkyū-buntansha) |
KOIZUMI Akio IWT, Akita Prefectural Univ., Assistant Professor, 木材高度加工研究所, 助教授 (40183040)
IIJIMA Yasuo IWT, Akita Prefectural Univ., Professor, 木材高度加工研究所, 教授 (10279507)
USAKI Seizo Faculty of Engineering and Resourse Sience, Akita Univ., Professor, 工学資源学部, 教授 (50006681)
KOMATSU Kohei Wood Reseach Institute, Kyoto Univ., Professor, 木質科学研究所, 教授 (20283674)
OKAZAKI Yasuo IWT, Akita Prefectural Univ., Lecturer, 木材高度加工研究所, 講師 (70279511)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥7,900,000 (Direct Cost: ¥7,900,000)
Fiscal Year 1999: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1998: ¥5,100,000 (Direct Cost: ¥5,100,000)
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| Keywords | Timber bridge / stress-laminated deck / monitoring / creep / mechano-sorptive / 遠隔現場モニタリング |
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| Research Abstract |
The glued laminated timber (glulam) tied arch bridge "Hyakume-ishi" located on a forest roadway in Akita Prefecture, Japan was completed in March 1999. The bridge also used using Japanese cedar grown in the prefecture. The bridge length is 20.9m with span length is 20.0m. The clear roadway width is 5m. In this study, a remote monitoring system for the long term measurement of the stress losses under environmental changes of the bridge in service was developed. The data from the measuring device that consists of six load-cells, a thermometer and a hygrometer are sent to a central station about 100 kilometers away automatically using a telephone line and modem at constant time intervals. These measured data were corrected using the remote monitoring control program. Temperature and humidity of the backside of the bridge are simultaneously monitored. The data are analyzed to determine the characteristics of this type of bridge during actual service. Results showed that the bar force loss already reached almost the maximum 60% level within less than a year. One possible reason is the use of a water-borne preservative for the preliminary pressure treatment of the glulam members. Changes in humidity, either increase or decrease, cause creep in wood and wood products. This effect is known as mechano-sorptive creep.
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