2006 Fiscal Year Final Research Report Summary
Research on The Establishment of An Earthquake Response Analysis Scheme and The Improvement in Damping Performance of A New Type of Seismic Isolation System Composed of Piles Covered by Pipes and Partial Soil Improvement with Damping Devices
| Project/Area Number |
15360303
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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 | Nihon University Junior College |
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Principal Investigator |
SHIMOMURA Yukio Nihon University Junior College, Department of Construction, Professor, 建設学科, 教授 (00060179)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIMARU Shinji Nihon University, Department of Architecture, College of Science and Technology, Professor, 理工学部, 教授 (50059573)
KAWAMURA Masashi Nihon University, Department of Architecture, College of Industrial Technology, Professor, 生産工学部, 教授 (80059849)
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| Project Period (FY) |
2003 – 2006
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| Keywords | Soft ground / Foundation block / Scrap tire tips / Asphalt with crushed stones / Damping performance / Mitigation performance of vibration / Forced vibration test / Earthquake observation |
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| Research Abstract |
In the initial year, a foundation block (CF) with a square area of 2.4m x 2.4m and with a height of 1.0m was structured by a conventional technique on the experiment site improved by four soil cement columns (diameter:600mm, length:2.5m), and forced vibration tests were conducted. In the next year, a new foundation block of the same size was constructed 6m to the east of CF by the same technique as the previous year, and forced vibration tests were conducted by changing the conditions of the side surface. At the last stage of this test (the trench depth of the side surface of foundation was 0.8m), a damping composite material was backfilled into the trench of the new foundation block (IF), and forced vibration tests were performed. The damping material is a mixture of asphalt with crushed stones and scrap tire tips. After the experiment, the earthquake observation has been continued. The main new findings obtained from the tests, the earthquake observation and the simulation analyses of them are as follows:
The IF could quantitatively clarify damping performance and vibration reduction better than the CF. First of all, from the result of the forced vibration tests, it was confirmed that in the case of IF, the response displacement per unit of excitation force was reduced approximately 30% at the dominant frequency, being compared to the case of CF. Next, more response reduction was confirmed in the IF than the CF from the transfer functions, which were presumed from the data of earthquake observations of 32 waves including the Mid Niigata Prefecture Earthquake in 2004. However, its decrease ratio was not to the extent of the case of forced vibration tests. It is attributed to the small sizes of foundation blocks and the small inputs from the side surfaces.
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Research Products
(32 results)
