1996 Fiscal Year Final Research Report Summary
A STUDY ON DYNAMIC CHARACTERISTICS OF TRADITIONAL WOODEN BUILDING BY MICRO TREMOR MEASUREMENT
| Project/Area Number |
06452290
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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 | NARA NATIONAL CULTURAL PROPERTIES RESEARCH INSTITUTE |
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Principal Investigator |
UCHIDA Akito NARA NATIONAL CULTURAL PROPERTIES RESEARCH INSTITUTE CENIRE FOR ARCHAEOLOGICAL OPERATIONS,DIVISION OF RESEARCH,SENIOR RESEARCH OFFICER, 埋蔵文化財センター・研究指導部, 主任研究官 (90142017)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAI Naohito BUILDING RESEARCH INSTITUTE,MINISTRY OF CONSTRUCTION,RESEARCH DIVISION 3, SENIOR, 第3研究部, 主任研究員 (70186047)
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| Project Period (FY) |
1994 – 1996
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| Keywords | TRADITIONAL WOODEN BUILDING / MICRO TREMOR / FFT ANALYSIS / NATURAL FREQUE / VIBRATION MODE / DAMPING FACTOR |
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| Research Abstract |
To understand dynamic characteristics of traditional wooden buildings, micro tremor measurements were performed on rebuilt buildings of Heijo palace site and Horyuji buildings. By the FFT analysis we obtained the knowledges as the following.
1. Rebuilt buildings : Four spectrum peaks from 4Hz to 10Hz, and three vibration modes which were parallel mode in the ridge direction, parallel mode in the beam direction and torsional mode in order from lower frequency. Analytic natural frequencies and vibration modes agreed well with those of measurement in lower frequencies.
2. Horyuji pagoda : Three natural frequencies under 10Hz, which were 0.9Hz, 2.5Hz, and 4.2Hz. Vibration mode at 0.9Hz was parallel mode in the diagonal direction and at 2.5Hz it was virtical second mode with phases reversed at the height of 5th story culumn botom. Locus of 5th story shows sometimes parallel vibration and sometimes circular vibration. Values of stiffness which decrease as the story number increase.
3. Kondo and
… More
Chumon : Two natural frequencies for each building under 10Hz, which were 1.80Hz and 2.07Hz for kondo and 1.56Hz and 1.80Hz for Chumon. For both buildings, primary vibration mode was parallel mode in the beam direction and second mode was parallel mode in the ridge direction. Damping factors were 1.7-4.4%. Values of stiffness of Kondo first story calculated from natural frequencies were 2.79-3.69*10^4kg/cm and the percentage of stiffness due to column rocking resistance is considered to be 75-81%.
4. Dai-kodo : Four natural frequencies under 10Hz, which were 1.7Hz, 2.1Hz, 2.5Hz and 4.1Hz. Primary vibration mode was parallel mode in the beam direction and second mode was parallel mode in the ridge direction. The Third mode was twist mode in the beam direction. Damping factors were 1.9-2.5%. Values of stiffness of Dai-kodo calculated from natural frequencies were 1.9-2.5%. Values of stiffness of Dai-kodo calculated from natural frequencies were 1.62*10^4 -2.50*10^4 kg/cm and the percentage of stiffness due to column rocking resistance is considered to be 88-95%. Less
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