Analyses Of Static And Dynamic Performance Of Long-Span Half-Through Concrete-Filled Steel Tubular Truss Arch Bridge And Detailed Stress Of Its Arch Springer

Firstly,the characteristics,the development course and the structural forms of concretefilled steel tube truss arch bridge were introduced in the thesis.The overall design scheme and design parameters of the main components of the bridge were outlined for the 228 m-span highway through concrete-filled steel tube truss arch bridge.The finite element model of the whole bridge based on beam element was established by Midas/Civil.The concrete-filled steel tube truss arch members were simulated by composite section,the suspenders were simulated by truss element,and the bridge deck was simulated by beam element.The construction process of the concrete-filled steel tubular truss arch bridge was simulated,and the deformation,internal force and stress of each member of the bridge in each construction stage were calculated and analyzed.Considering the loads such as dead load,live load,wind load and temperature load,the loads were combined according to the most unfavorable conditions.The deformation,internal force and stress of each member of the bridge in operation stage were calculated and analyzed.According to the finite element model of the whole bridge with beam elements,the Ritz method was used to calculate the natural vibration characteristics of the bridge and analyze the vibration mode characteristics of each order of the bridge.Calculating the response of each bridge member by inputting E1 and E2 seismic response spectrum respectively.The earthquake time history response of each bridge member was calculated by selecting the appropriate acceleration time history of ground motion.Beam element model was used to analyze the stability of bridge during arching stage,bridge forming stage and operation stage.At the operation stage,the bridge stability under two different modes of dead load,live load synchronous increment and live load increment only was calculated.By using the general finite element software Midas/FEA,the whole bridge model of local detailed integrated element based on arch springer,bridge deck and beam was established.The stress distribution of arch springer was calculated by the model.