Research On Dynamic Performance Of Concrete-filled Steel Tubular Trussed Arch Bridge Under Earthquake

Earthquake has always been a major serious natural disaster to human, bridges plays a very important role in the city's earthquake prevention and disaster reduction system. In recent years, concrete filled steel tubular trussed arch bridges constitute a high proportion of the construction of China's large-span bridges, which will achieve greater development. But there is little practical seismic test data of this bridge due to it has been a relatively short time since this structure appears, and the research of its seismic mechanism against earthquakes is not clarity and mature enough. So the research on dynamic performance of concrete filled steel tubular trussed arch bridge is very necessary.On the basis of seismic response theories and took a double span-swallows-type concrete filled steel tubular trussed arch bridge as an example, this paper did a research on dynamic performance of the concrete filled steel tubular trussed arch bridge. The main contents include:1. Set up a computational model of the example bridge, calculated its dynamic characteristics, and analyzed its natural vibration period and vibration characteristics;2. Analyzed the seismic response characteristic of the example bridge by response spectrum method and time-history method in four combination conditions (the longitudinal, horizontal and longitudinal+vertical and horizontal+vertical); summarized the impact of seismic input direction to the structure's internal forces and displacements; comparing the response spectrum results with the corresponding dynamic time history analysis results, discussed the applicability of the two methods, and made some recommendations accordingly to seismic design of the large span concrete filled steel tubular trussed arch bridge.3. Comparing time history analysis results of the example bridge in different wave speed, discussed the effect of the traveling wave effect on seismic response;4. Comparing time history analysis results of the example bridge with or without considering the pile-soil-structure interaction, discussed the effect of pile-soil-structure interaction on seismic response of structures.