1987 Fiscal Year Final Research Report Summary
Earthquake Resistance of Beam-Column Connections in Weak-Beam Strong-Column Reinforced Concrete Frames
| Project/Area Number |
60420040
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Building structures/materials
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| Research Institution | University of Tokyo |
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Principal Investigator |
OTANI Shunsuke University of Tokyo, 工学部, 助教授 (30133101)
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| Co-Investigator(Kenkyū-buntansha) |
TASAI Akira University of Tokyo, 工学部, 助手 (40155057)
HOSOKAWA Youji University of Tokyo, 工学部, 助手 (60011235)
AOYAMA Hiroyuki Nmiversit of Tokyo, 工学部, 教授 (80010669)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Reinforced Concrete / Weak-Beam Strong-Column / Beam-Column Joint / Shear Transfer Mechanism / Permissible Deformation / Earthquake Resistant Design Criteria / Bond along Beam Bars / 横補強筋 |
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| Research Abstract |
The shear transfer mechanism of a reinforced concrete interior beamcolumn joint was studied through the laboratory tests of plane specimens under reversed cyclic loading and the nonlinear finite element analysis. The joint shear transfer mechanism changes with bond deterioration along the beam reinforcement. When a good bond is maintained along the beam reinforcement, diagonal compressive stresses distribute uniformly within the joint panel. However, the compressive stresses come to concentrate on the joint main diagonal with the bond deterioration. The transverse reinforcement within the joint does not contribute to the shear resistance, but confines the joint core concrete.
Three-dimensional beam-column joints with slabs were tested under the bi-directional loading reversals. The joint shear failure was not observed during the tests despite fo a high shear force input into the joint. The transverse beams framing into the joint and the slabs confined the joint core increasing the joint shear resistance.
The earthquake resistant design criteria were proposed for interior beam-column joints taking into account the expected deformation limits of structures designed by the weak-beam strong-column concept. The bond deterioration along the beam reinforcement may be permitted to some extent, the limit which was determined on the basis of the nonlinear earthquake response analyses. The shear force input into the joint must be limited in proportion to the concrete compressive strength in order to prevent the joint shear compression failure after beam flexural yielding.
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