| At present, the arch bridge was widely used, of which CFST arch bridges accountsfor a considerable number, but less dynamic characteristics and seismic analysis andresearch for CFST arch bridges relative to other types of bridges. In recent years, theglobal earthquake occurs sometimes, especially for destructive earthquakes, seriousharm to people’s property and life safety. If the structure of bridge is destroyed duringan earthquake, will cause traffic disruption, and difficult to repair in short-term, so willdelay relief for earthquake, enable secondary disasters increase, thus furtheraggravating earthquake disaster. Therefore, it is necessary to study the dynamiccharacteristics and seismic performance of such type of bridge for better understandingof its dynamic characteristics and seismic response and to establish the reasonableanti-seismic structure system of the bridge, take effective anti-seismic measures, forseismic design and analysis of the bridge providing the scientific basis.This paper, on the basis of research results at home and abroad, a model of finiteelement of a through CFST arch bridge was established based on the large finiteelement analysis software, the dynamic characteristics ware analysed. The influence ofthe dynamic characteristics for different components of the through tied CFST archbridge was studied by changing the stiffness of the different components. Theinfluence of the dynamic characteristics for the through CFST arch bridge was studiedby changing the number of crossbars and arrangement type. Research shows thatcrossbars have significant influence on transverse and twist vibration. The contributionof crossbars near the foot of arches more for resistance of arch low order transversevibration. The contribution of crossbars near the top of arches less for resistance ofarch low order transverse vibration, but more for resistance of arch high ordertransverse vibration. For dynamic properties, crossbars main impact span of itself,have no influence for other span.“” form crossbar better than K form crossbar.Longitudinal beams and bridge decks influence vertical and twist vibration. Theycontribute little to resist transverse vibration. Cross beams have a great contribution toresist twist vibration, but less to vertical vibration and transverse vibration. Thecontribution of derricks and ties for improving dynamic characteristics of the structurewas little, which can be ignored. The acceleration response spectrum of standard was input as Guidelines forSeismic Design of Highway Bridges. The acceleration response spectrum was inputalong the bridge, cross-bridge, vertical and three multi-dimensional combinations, theresponse of the displacement and internal force for key parts of the bridge were studied.Using time history analysis on seismic sesponse, the seismic wave was input along thebridge, cross-bridge, vertical and three multi-dimensional combinations as uniformexcitation, the response of the displacement and internal force for key parts of thebridge were studied. Consider the effect of traveling wave along the bridge, indifferent velocity of seismic waves actioned, the response of key parts of the bridgewere studied as considering traveling wave effect. The results for the responsespectrum method and time history analysis method were comparisoned and analysised.Research shows that earthquake of cross-bridge influence for arch transverse vibration.Along the bridge and the vertical seismic, effect rib occurrence of the longitudinalvibration and vertical vibration. The Rib horizontal maximum displacement occurredin the location of the vault. The bridge to the maximum displacement for longitudinaland vertical occurs mostly in about a quarter arch positions. The internal force of archrib is symmetrical along the arch rib, maximum usually in the feet of arch position. Inthe design and analysis, should consider the role of multidimensional earthquake andthe traveling wave effect on the effect of bridge structure. |
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