2005 Fiscal Year Final Research Report Summary
Seismic retrofit schemes for RC building structures using displacement controling devices without bolt anchorage
| Project/Area Number |
16560497
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | Kyoto University |
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Principal Investigator |
KONO Susumu Kyoto University, Architecture, Assoc.Professor, 工学研究科, 助教授 (30283493)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Fumio Kyoto University, Architecture, Professor, 工学研究科, 教授 (50026267)
TANAKA Hitoshi Kyoto University, DPRI, Professor, 防災研究所, 教授 (20132623)
NISHIYAMA Minehiro Kyoto University, Architecture, Assoc.Professor, 工学研究科, 助教授 (50183900)
SATO Yuichi Kyoto University, Architecture, Assistant Professor, 工学研究科, 助手 (20293889)
KANAO Iori Kyoto University, Architecture, Assistant Professor, 工学研究科, 助手 (80372564)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Seismic retrofit / Prestessed concrete brace / No bolt anchorage / Self-centering / Damper / PCa brace / Seismic damage / Damage control |
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| Research Abstract |
After major earthquakes in big cities in 1990's, the seismic upgrading of existing buildings have been attracting more attention than ever. However, many existing buildings have not had seismic upgrading since construction cost is high due to intensive labor work and the buildings are out-of service during construction. This research aims to propose a simple seismic strengthening method which satisfies a) no wet concrete work, b) no rebar or bolt anchorage, c) short construction period, and d) low construction cost. For this purpose, a precast prestressed concrete brace system has been developed to demonstrate its efficiency experimentally and analytically.
In an experimental phase, two identical half scale portal frames were constructed based on the old Japanese building standard and strengthened with propose bracing system with different section dimensions. Both frames showed more than 70% increase in lateral load carrying capacity and the efficiency of the bracing system was proved. Additional experiment was carried out on four 1/3 scale beam-column-brace joint models to evaluate the shear and bearing strength. In an analytical program, the nonlinear and dynamic frame analyses have been conducted to evaluate the effect of end fixity and out-of-plane deformation of braces on the performance of braced frames. It was shown that the failure mode of braced frames involved the tension failure of the first story column due to the cantilever action, buckling or crushing of concrete brace, axial tensile failure of beams, and the bearing failure at joints. Based on the experimental and analytical results, economical and simple strengthening procedure using concrete brace and its design method is proposed. The proposed system can be applied to new buildings instead of using shear walls. A few retrofitted and newly strengthened buildings using the proposed method are introduced.
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Research Products
(8 results)
