| Project/Area Number |
06452260
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
構造工学・地震工学
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| Research Institution | Hokkaido University |
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Principal Investigator |
SAEKI Noboru Hokkaido Univ., Fac. of Eng., Professor, 工学部, 教授 (80002004)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMURA Kazunori Hokkaido Univ., Fac. of Eng., Instructor, 工学部, 助手 (60187474)
UEDA Tamon Hokkaido Univ., Fac. of Eng., Associate Professor, 工学部, 助教授 (00151796)
MIKAMI Takashi Hokkaido Univ., Fac. of Eng., Professor, 工学部, 教授 (00002303)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | Torsion / Bending / Shear / Space truss model / RC plate model / Effective cover / Warping / Diaphragm / RC平板モデル / せん断ひずみ / St.Venantのねじり / ねじり剛性 |
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| Research Abstract |
(1) Ultimate strength and failure modes of reinforced concrete member subjected to combined torsion, bending and shear
The space truss theory is advanced by superposing torsional, bending and shear force, and fundamental equations are derived. By using an iterative method stress and strain can be calculated and checked on the failure. Failure modes are classified as 1)yielding of transverse bars, 2)crushing of diagonal concrete struts, 3)compressive-shear fracture of compressive region and 4)flexural fracture. According to the comparison with the calculated values and results of experiments, the proposed method is available to predict the ultimate strength and failure mode under arbitrary combined loads of torsion, shear and bending.
(2) Deformation of reinforced concrete member subjected to torsion
At first, the effective cross section for torsion is assumed to reinforced concrete plates with and without cracks. Then fundamental equations are derived from equilibrium conditions and compatibility conditions considering tensile stress of concrete. Spalling of cover of concrete at post cracked region is estimated by effective cover using the proposed index of shear strain at cover. Though calculated deformation tends to estimate conservatively in comparison with test results, it is shown that this method predicts approximately torsional deformation.
(3) Torsional behavior of reinforced concrete member with diaphragms
Torsional behavior of reinforced concrete member with diaphragms is evaluated. The warping stress occurs because warping is confined by diaphragms, therefore mixed torsion theory is applied. According to the comparison with the calculated values and results of experiments, it is found that the proposed method evaluates torsional stiffness in the region before crack occurs.
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