2004 Fiscal Year Final Research Report Summary
Collapse mechanism of pilotis buildings and development of displacement distribution structural system
| Project/Area Number |
15360304
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | National Research Institute for Earth Science and Disaster Prevention |
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Principal Investigator |
ZHANG Fuming National Research Institute for Earth Science and Disaster Prevention, Earthquake Disaster Mitigation Research Center, Research Engineer, 地震防災フロンティア研究センター, 研究員 (30360366)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAI Hisakazu National Research Institute for Earth Science and Disaster Prevention, Earthquake Disaster Mitigation Research Center, Research Engineer, 研究員 (00360371)
プリード ネルソン 独立行政法人防災科学技術研究所, 研究員
MUKAI Youichi Osaka University, Graduate School of Engineering, Assistant Professor, 大学院・工学研究科, 講師 (70252616)
TANI Akinori Kobe University, Graduate School of Science and Technology, Associate Professor, 大学院・自然科学研究科, 助教授 (50155199)
KAWAMURA Hiroshi Kobe University, College of Engineering, Professor, 工学部, 教授 (70031119)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Pilotis building / Damage / Collapse / Pulse ground motion / Structural control / Vibration mode / Seismic design |
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| Research Abstract |
The object of this research is to investigate the collapse mechanism of pilotis buildings, and to develop a new structural system for preventing the collapse at the first story of buildings.
In order to investigate the collapse of reinforced concrete pilotis building, a numerical integration method was developed using the correct instantaneous stiffness of elements by predicting the time increment compatible with stiffness variation. The collapse of reinforced concrete columns was discussed using fiber model at plastic hinge and considering the horizontal and vertical vibrations. It was found that column models will collapse at a smaller earthquake input level for a simultaneous input of vertical motion, the ultimate safety of buildings should be evaluated considering the 3-dimensional dynamic behaviors of vertical members. Recent near-fault earthquakes shown strong pulse-like ground motion component in velocity, explicit formulas and simplified methods are efficient to highlight the de
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structive power of ground motions. Here, earthquake motions are simplified as rectangular acceleration pulses and velocity pulses that are solely related with peak values of ground motions, and explicit formulas are obtained that give an extremely simple correlation between structural response and seismic demand with peak values of ground motion.
In order to eliminate deformation concentration of building structures, Rocking Center Designated (RCD) Mechanism is proposed to control the vibration modes. Firstly, the dynamic characteristics of this new structure were investigated, and its seismic design method was proposed. The effectiveness and advantages were discussed for design of new buildings and for retrofitting of existing buildings. To confirm the vibration properties of this new structure, Small shaking table tests were carried out to confirm the function of RCD mechanism for displacement distribution. Test results shown that the vibration mode of the main structure varies according to the rocking center of RCD mechanism. If the rocking center is under the ground level, then the first vibration mode will be predominant, and will be solely decided by the rocking radius geometrically, and the story forces are effectively relocated by RCD mechanism. This new structure system is expected to meet different performance needs for distributing the first mode displacement, and to choose the most suitable structural member for strength, deformation and energy consumption. Less
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Research Products
(15 results)
