Study of Ultimate Lateral Load-capacity of Pile Groups under Axial and Lateral Forces
| Project/Area Number |
61550413
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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 | Hiroshima University |
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Principal Investigator |
TOMINAGA KOJI. HIROSHIMA UNIV., FACULTY OF ENGINEERING, Associate Prof., 工学部, 助教授 (10067720)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO HARUYUKI. HIROSHIMA UNIV., FACULTY OF ENGINEERING, Research Assist., 工学部, 助手 (60158293)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Interaction of Pile and Soil / Effect of Pile Groups / Ultimate Lateral-Load Capacity / Ductility of Pile Foundation / Additional Moment / アーチ効果 / 群抗効果 / 鉛直力による付加曲げアー4効果 / 保有水平耐力 / 群杭の相互作用 / 鉛直と水平の合成力 |
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| Research Abstract |
The results and informations obtained from theoretical and experimental studies on the lateral behavior of pile group foundations up to failure under combined load can be summarized as follows.
1. In order to apply simultaneously both axial and lateral forces at the cap of pile group foundation, the apparatus having the lateral moveng container on two rails was developed. the accuracies of conditions during all tests carried out were examined.
2. Group efficiency due to the interaction of piles gradually decreases as the pile spacing, R, increases. For R=2D(D:pile diameter), however, it is observed that the behavior deffers from others because of arch-action in sand. Furthermore, it is indicated that at the ultimate state of pile group foundations the deflection decreases and the lateral resistance increases as R increases.
3. In general, it is found that the group reduction factor decreases with increasing numbers of piles in a group, and increase in number leads to increase in ductility of pile group foundations.
4. For the pile groups subjected to vertical load, the lateral load-deflection curves have a peak, and the ultimate lateral resistance is reduced because of the additional moment caused by deflection, as compared the results without vertical force.
5. The analytical method, in which the method of incremental displacement is used to predict the nonlinear behavior up to failure due to yielding of soil and pile, is predicted. Comparisons between the observed and predicted load-deflection behavior are made. It is found that the agreement between predicted and observed curves is reasonable for single piles and pile groups at large spacings, but the theory overpredicts movements and underpredicts ultimate lateral resistances for pile groups at close spacings.
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Report
(3 results)
Research Products
(10 results)
