Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2000: ¥2,100,000 (Direct Cost: ¥2,100,000)
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Research Abstract |
While hybrid structures are paid attention to, highway bridges with small number of girders become noteworthy from a viewpoint of rationalization of bridge system in design, fabrication and construction. Twin-girder bridge's relative deflections of slab to main girders due to traffic loads may be greater than those of ordinal girder bridges, because slab's span length of the former is longer than that of the latter. The relative deflections near expansion joints can give rise to some problems like low frequency vibration due to traffic-induced vibration. Therefore, for not only the main girder response but also the slabs and web plates behavior, a three-dimensional dynamic response analysis of a bridge is carried out to investigate the dynamic response characteristics of a twin-girder bridge under moving vehicle loads in this research. In modeling a vehicle-bridge interaction system, 8-degree-of-freedom vehicle model and FE model with shell element, which are adopted to express the real bridge more clearly, are used The analytical results of bridge agreed well with the experimental results. It becomes cleared that, since elastomeric support displaces in vertical direction, acceleration responses of the bridge are amplified, when a vehicle passes the expansion joint of the bridge. Out of plane acceleration responses of web plates are also amplified due to the slab's long span. In addition, it was confirmed that natural frequencies of web plates are distributed between 15Hz and 27Hz.
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