1998 Fiscal Year Final Research Report Summary
Failure Mechanism of Concrete Pile
| Project/Area Number |
09650620
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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 | TOKYO INSTITUTE OF TRCHNOLOGY |
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Principal Investigator |
HAYASHI Shizuo Material and Structural Laboratory, TOKYO INSTITUTE OF TRCHNOLOGY,Professor, 応用セラミックス研究所, 教授 (90092569)
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| Co-Investigator(Kenkyū-buntansha) |
KATORI Keiichi Material and Structural Laboratory, TOKYO INSTITUTE OF TRCHNOLOGY,Research Assis, 応用セラミックス研究所, 助手 (50224556)
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| Project Period (FY) |
1997 – 1998
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| Keywords | PRESTRESS / SHEAR FAILURE / SHEAR COMPRESSION / FEM ANALYSIS / 3-DIMENSIONAL / DUCTILITY |
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| Research Abstract |
Analysis on the Seismic Behavior of Reinforced Concrete Building supported by Pile
In making structural calculation, a building is commonly divided into two parts, aboveground part and underground part. As already mentioned, it is not legal obligation to examine the ultimate strength for the underground part. So, the ultimate strength of the underground part was left unknown. Therefore, many reinforced concrete buildings were damaged at the underground part due to the 1995 Hyougoken Nanbu Earthquake without damage of aboveground part.
Here, we analyzed the damage considering the interdependence of aboveground part and pile. In order to simulate the interaction between axial force and bending moment, the multi spring model is introduced here. A 7 storied reinforced concrete building is analyzed. At first, we analyzed only the aboveground part of this building, alone. Yielding has occurred at the end of almost beams. This is ideal hinge mechanism. Next the aboveground part and underground
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part are analyzed together as a body. The yielding has occurred at the top of pile in the early stage before beams reach at the yield curvature. This agreed with the damage due to the earthquake.
Shear Strength of Pre-cast High Strength Concrete Pile
This is the comparison between analytical result and experimental maximum shear strength. The horizontal axis shows the sum of the axial stresses, pre-stress and external axial stress. When the sum of axial stresses is low, the analytical results are larger than the experimental one. The equation was proposed by Shibata and Joh in order to calculate the ultimate shear strength of column with square section. We apply this equation to the pile with cylindrical section. The higher the sum of axial stresses becomes, the lower the factor of safety is. We examine the possibility that the pile fails by shear before the yielding has begun at the top of pile. In almost cases, the shear strength is smaller than the shear force when yielding has begun at the top of pile. The PHC pile now in use in Japan tends to cause the shear failure. Less
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