| Project/Area Number |
07650546
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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 |
構造工学・地震工学
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| Research Institution | TOTTORI UNIVERSITY |
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Principal Investigator |
SHIRAKI Wataru TOTTORI UNIVERSITY,CIVIL ENGINEERING,ASSOCIATE PROFESSOR, 工学部, 助教授 (30032288)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUHO Shigeyuki TOTTORI UNIVERSITY,CIVIL ENGINEERING,RESEARCH ASSOCIATE, 工学部, 助手 (90157347)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | highway bridges / fatigue reliability / large size truck / reinforcement and repair / earthquake reliability / 設計自動車活荷重 / 亀裂進展則 |
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| Research Abstract |
In the new version of Japanese Highway Bridge Specifications revised in February, 1994, the design vehicle load is changed from 20 tf to 25 tf according to revision of the standard of the traffic vehicles. The change of design vehicle load is considered to be concerned with the reduction of fatigue reliability of existing highway bridges designed by the old version of the specifications. In this study, first, the influence is estimated by the fatigue reliability analysis of typical types of steel girder bridges. The analysis is performed for the vertical stiffeners connecting the central transverse girder to the web of the main girders by the use of a probabilistic fracture mechanics model and Monte-Carlo simulation technique. Second, a planning method of repair and reinforcement for highaway bridges is investigated. Furthemore, the reliability evaluation of rigid-frame steel pires of highway bridges subjected to earthquake load is done. The main results obtained in this study are as follows :
(1) The change of traffic vehicle design load give a large influence on the fatigue reliability of bridges designed by the new version of the specification as well as the old one. The investigations for maintenance such as reinforcement and repair are required.
(2) A optimization method which maximize the expected total cost benefit is introduced. The optimal method is introduced to determine the total number of repair, type of repair, and the time required for repair.
(3) The studies on the fatigue reliability analyzes are performed for concret bridges, however, the results mentioned specially are not obtained.
(4) The reliability levels for steel pires of existing highway bridges designed by the allowable stress design method (ASDM) are evaluated, and then the influence of load effect due to earthquake on reliability of pier structures is examined in detail. Some shortcomings of the ASDM are pointed out.
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