| Project/Area Number |
10555158
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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 |
構造工学・地震工学
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| Research Institution | Kumamoto University |
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Principal Investigator |
AKIYOSHI Takashi Kumamoto University, Department of Civil Engineering and Architecture, Professor, 工学部, 教授 (60040383)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRINASHIHAMA Shozo Tekken Kensetu Co., Research Institute, Research Associate, 技術研究所, 研究員
HYODO Takeshi Wakachiku Kensetsu Co., Department of Civil Engineering Design, Research Associate, 土木本部設計部, 研究員
FUCHIDA Kunihiko Yatsushiro College of Technology, Department of Civil and Architectural Engineering, Associate Professor, 助教授 (80124155)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1998: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | aseismic design method / response spectra / two axis response spectra / natureal period / liquefaction / ground improvement / pile foundation / nonlinear ground vibration |
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| Research Abstract |
This study aims to establish a optimal aseismic design method which minimizes the response spectra under the condition of non failure of ground and non failure of pile foundations, using two axis response spectra of natural period of ground-pile system and natural period of 1 DOF upper structure system. This design method is investingated first for the fundamental ground-structure models in terms of seismic intensity, pile and soil parameters, and finally applied to the examples of fatal damaged pile-supported massive buildings resting on the soft ground at Kobe in 1995 Hyogoken Nanbu earthquake. It is also confirmed that this proposed method is realized in the laboratory for scaled models using the shaking table for random inputs.
Results obtained are summarized as follows :
1. By equipping the absorbing boundary conditions into existing program of liquefaction analysis, free field can be realized exactly in the personal computer. The program of ground improvement by sand compaction pile (SCP) method become applicable to every soil and construction condition from sand to clay.
2. Minimum compaction time per one stage in the construction of SCP is adopted as the optimal criteria for prevention of liquefaction and pile failure. As a result, it is shown that most damaged examples at Kobe can be designed safely event for the earthquake of 540gal by extending the compaction time. However exact estimation of positions of pile damages will depend on consideration of large lateral flow of soil due to liquefaction.
3. After the laboratory test of one-degree-of-freedom system structural model resting on the original soft ground or improved ground subjected to the 1995 Hyogoken Nanbu earthquake, experimental response spectra agrees well with the computational one. Compaction rate of improved grounds also agree well with simulation results. Hence it is shown that the proposed method is also realized experimentally.
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