1993 Fiscal Year Final Research Report Summary
Experimental Study on the Method to Reinforce Plastic Hinge Region of High Strenght Concrete Filled Steel Tubular Columns
Project/Area Number |
04650527
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Building structures/materials
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Research Institution | KYUSYU UNIVERSITY |
Principal Investigator |
SAKINO Kenji Kyushu Univ., Faculty of Eng., Professor, 工学部, 教授 (70037985)
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Co-Investigator(Kenkyū-buntansha) |
NINAKAWA Toshihiko Kyushu Univ., Faculty of Eng., Research Assistant, 工学部, 助手 (90237769)
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Project Period (FY) |
1992 – 1993
|
Keywords | Concrete Filled Steel Tubular Square Column / Improvement of the Seismic Resistant Performance / Reinforcing by Embedded Circular Steel Tube / Axial Shortening / Ductility / High Axial Compression / Tall Building |
Research Abstract |
We have devised a method for improving seismic resistant performance of concrete filled square steel tubular columns to reinforce by embedding circular steel tube in the column. In order to verify the efficiency of this method, experimental investigation on the columns subjected to alternately repeated lateral force under constant axial compression has been conducted. Eighteen specimens devided into three types according to the length of reinforced region. First type was the partially reinforced columns which have embedded circular steel tube in only the plastic hinge regions with a length of column depth, second type was the totally reinforced columns which have embedded cicular steel tube in the clear height of the column, third type was unreinforced columns which have no circular steel tube. The depth of square steel tube was 200mm and wall thickness was 6mm or 9mm. Concrete strenghth was 260-317kg/cm^2. The variable parameter was the magnitude of constant axial force, which was varied from 0.3 to 0.6 in axial force ratio. In the experiment, all the columns which were reinforced by embedded circular steel tube behaved in a ductile manner and could be prevented from an axial shortening compared with unreinfoced columns. The efficiency of this reinforcng method was remarkable under high axial compression or at large deformation especially, however, only the totally reinforced columns showed good performance under high axial compresssion. In terms of the axial shortening this reinforcing method was more effective than the method to increase the wall thickness of square tube. It can be concluded that by using the proposed method in the structures of concrete filled square steel tubular columns good seismic resistant performance can be obtain.
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Research Products
(8 results)