| Project/Area Number |
02805069
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Building structures/materials
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| Research Institution | Chiba University |
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Principal Investigator |
UESUGI Morimichi Chiba University, Engineering, Associate Professor, 工学部, 助教授 (20151780)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Toru Chiba University, Engineering, Research Associate, 工学部, 助手 (10226855)
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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 |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Piles / Sandy Ground / Model Test / Shaft Resistance / Test Method / Relative Density / Lateral Pressure / Coefficient of Lateral Presssure / 抗 / 摩擦 / 砂 / 地盤 / 側方土圧 |
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| Research Abstract |
The reliability was examined on the model tests of shaft resistance acting on piles in sand under axial load. Testing procedure was proposed to improve the reliability of the results. The improvement was examined in comparison with previously reported studies.
The research was focused on the lateral stress acting on the model pile in a small chamber of its diameter about 30cm.
1. In the conventional procedure, the horizontal stress applied to the model ground in the small chamber was kept constant during the penetration of the model pile. The lateral stress acting on the pile was lower than the values from the tests in large chambers of its diameter about 80cm or larger.
2. In the present procedure, the water valve was closed after the application of the initial horizontal stress to the model ground in the chamber. The lateral stress acting on the pile was close enough to the values from the tests in large chambers under the same initial condition.
3. The lateral stress acting on the pile depends on the lateral density and initial coefficient of lateral pressure as well as the horizontal pressure applied to the outer boundary of the model ground.
4. The difference in the above 1. and 2. implies that the lateral stress on the pile depends on the externally confining pressure acting on the outer boundary of the model ground during the penetration of the pile. The magnitude of the external confinement depends on the initial condition of the model ground as mentioned in the above 3.
5. It was confirmed by the test results that the shaft resistance of pile in sand depends on the lateral stress acting on the shaft surface but not directly influenced by the relative density of the ground.
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