2003 Fiscal Year Final Research Report Summary
Fundamental Research on High Seismic Performance RC Piers with Unbonded Bars
| Project/Area Number |
13450180
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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 |
土木材料・力学一般
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| Research Institution | Kyoto University |
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Principal Investigator |
IEMURA Hirokazu Kyoto University, Engineering, Professor, 工学研究科, 教授 (10026362)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Yoshikazu Kyoto University, Engineering, Research Assoc, 工学研究科, 助手 (10283623)
井上 晋 大阪工業大学, 工学部, 教授 (30168447)
IGARASHI Akira Kyoto University, Engineering, Assoc.Professor, 工学研究科, 助教授 (80263101)
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| Project Period (FY) |
2001 – 2003
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| Keywords | unbonded bars / RC structure / cyclic loading tests / pseudodynamic tests / single column pier / rigid frame pier / post-yield stiffness / seismic design method |
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| Research Abstract |
In this study, the UBRC structure was proposed as the high seismic performance structure in the next generation. And, the cyclic loading tests and the pseudodynamic tests were carried out in order to obtain the fundamental performance. Furthermore the analytical method for the UBRC structure was developed, and we carried out the parametric studies. From this study, the following results are obtained:
(1) By installing unbonded bars, it is possible to easily realize the RC structure with the stable post-yield stiffness. And the UBRC structure has small residual displacement in comparison with the conventional RC structure by the bar effect.
(2) The capacity of the energy dissipation is only depend on the amount of longitudinal reinforcement, and never change due to the installation of bars. That is to say, the optimal amount of longitudinal reinforcement for the UBRC structure is the equivalent to that of RC structure in order to expect the energy dissipation.
(3) From the results of the cyclic loading tests, it can be obtained the equivalent results to the principle got by installing the elastic member into RC structures. This structure can be realized only by installing unbonded bars into RC structure. Therefore this structure can be constructed with simple and easy construction works and low cost.
(4) In order to increase the post-yield stiffness, we have three method; Increase the bar ratio, Place bars outside and Shorten the bar length. By installing the gap at the anchor, the post-yield stiffness doesn't change. Changing these parameters, the various kind of the load -displacement hysteresis can be realized.
(5) In the pseudo dynamic tests it is also recognized the bars' effect (stable post-yield stiffness and the small residual deformation). Considering with the easy construction and the low construction cost, the UBRC structure has the high seismic performance.
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