2007 Fiscal Year Final Research Report Summary
Development of the most competitive performance-based limit state design method for composite girders
| Project/Area Number |
18360214
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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 |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
NAGAI Masatsugu Nagaoka University of Technology, Dept. of Civiland Environmental Engineering, Professor (20207971)
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| Co-Investigator(Kenkyū-buntansha) |
OKUI Yoshiaki Saitama University, Dept of Civil Engineering, Associate Professor (40214051)
IWASAKI Eiji Nagaoka Univ. of Technology, Dept of Civil and Environmental Engineering, Assoc. Professor (10223380)
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| Project Period (FY) |
2006 – 2007
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| Keywords | composite girders / double composite girders / composite hybrid girders / studs / crack width control design / Performance-based design method / Limit state design method |
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| Research Abstract |
Performance-based Limit State Design Method (PB-LSD) for designing structural members for infrastructure is now global standard. In Euro Code (EU) and AASHTO LRFD (USA), after 20-year energetic activity, the shift of design concept from Allowable Stress Design (ASD) to PB-LSD has just finished. Among Asian countries, where future preparation of infrastructure is expected and also are expected to be promising market, the above codes are now becoming popular. In Japan, for more than 30 years, ASD has been used. On designing composite girders, which is competitive structural members, and has been employed worldwide, in order to effectively utilize its mechanical characteristics, introduction of LSD is inevitable. From a viewpoint of competing with EC (EU) and AASHTO LRFD (USA), a shift from ASD to LSD has to be done immediately. In this research, based on analytical and experimental studies, original and competitive formulae for evaluating ultimate flexure, shear and interactive strength for composite girders were proposed, which are the most important items on establishing competitive LSD. On evaluating flexural strength, the criterion for judging to be compact section gives the most economical section. Regarding ductility condition taking into account of the decrease of plastic moment due to concrete crushing, the most competitive solution was given. On evaluating flexure and shear interactive strength, it was found that the interaction effect can be neglected in case of composite girders. In case of steel girder (under erection), it has to be checked. Original provisions were also proposed on checking serviceability limit state. Furthermore, the design method for double-composite girders and composite hybrid girders was also proposed.
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