Analysis On Seismic Response Of Concrete Filled Steel Tubular Arch Bridge

In recent years, earthquake disaster frequently occurred in whole world which brought great damage to the safety of life and property for people. If the bridges which looked as very important structures by people for connecting with people's life collapsed caused by earthquake, the indirect disaster will take up to bring more loss of life and property. Therefore it is necessary to study and master the seismic response of bridge for establishing reasonable seismic design system and adopting effective seismic measure. In this thesis, on the basis of the study achievements at home and abroad, on the basis of YONGHE Bridge of NANNING City, long span concrete filled steel tubular arch bridge'earthquake response were studied as follows: 1. Responsible formulations were used to describe the bridges' dynamic actions and appropriate method was chosen to solve these problems on the base of foregoing researches. 2. The finite element model of the structure was formed through reasonable simplification. And structural dynamic properties were calculated by using the famous program of ANSYS. Structural dynamic properties considering support rigidity,arch rib rigidity as well as soil-structure interaction were performed. 3. The standard seismic response spectrum was adopted to analyzing structural seismic response which the seismic response spectrum was inputted from longitudinal, transverse and vertical direction respectively. Structural working state in the most unfavourable seismic loads combination was preformed. 4. Long span concrete filled steel tubular arch bridges' responses to uniform excitation of earthquake were analysed. Structural seismic responses that seismic wave was inputted from vertical direction were discussed. Internal forces and displacements of structural crucial sections were compared and discussed for checking computation the seismic safety of the structure. Some beneficial conclusions were gained through comparing calculation results of response spectrum analysis and time-history analysis. 5. Long span concrete filled steel tubular arch bridges' responses to travalling-wave effect of earthquake were studied. In this study, acceleration time-history was translated into force time-history with big mass principle, and force time-history was exerted in support place. The influence of wave-velocity, earthquake-wave properties and structural dynamic properties to travalling-wave effect were discussed.