| Project/Area Number |
02452210
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Building structures/materials
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
TOKIMATSU Kohji Tokyo Institute of Technology Associate Prof., 工学部, 助教授 (50134846)
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| Co-Investigator(Kenkyū-buntansha) |
SHAMOTO Yasuhiro Shimizu Corporation Research Engineer, 技術研究所, 研究員
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1990: ¥3,300,000 (Direct Cost: ¥3,300,000)
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| Keywords | Foundation structure / Deformation / Sand deposits / Pile / Earthquake / Liquefaction / Interaction / Cyclic mobility / 応答変位 |
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| Research Abstract |
An effective stress analysis procedure is proposed for simulating dynamic response of a soil deposit involving soil liquefaction and cyclic mobility. The effectiveness of the proposed analysis is studied using accelerations and pore pressures which were recorded in soil deposits during earthquakes. The analytical results including time histories of acceleration and pore pressure and Fourier spectra are in good agreement with the observed values, indicating the effectiveness of the proposed analysis.
An analytical method is then presented for evaluating dynamic response of soil-pile-structure system during soil liquefaction. The method consists of a modified Penzien's model combined with the effective stress analysis and a horizontal subgrade reaction model which connects free field response with pilestructure response. Shaking table tests are conducted on soil-pile-structure models constructed in a large container, and the results are compared with analytical ones. The analytical results including the time histories of excess pore water pressures, accelerations, and displacements, and the Fourier spectra of the ground surface and the pile head, are all in good accord with the observed values, showing that the proposed analysis is effective.
The comparison of experimental and analytical results indicate that : (1)regardless of the rigidity of pile, the bending moment of the pile before liquefaction is significantly influenced by the deformation of the soil deposit : (2)unless the pile is rigid enough, the bending moment of the pile is also influenced by the deformation of the soil deposit : (3)the maximum bending moment of the pile is related better to the ground deformation than to the acceleration measured on the structure. Based on the above findings, a simplified method is presented for estimating bending moment of piles during soil liquefaction.
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