Analysis On The Static And Dynamic Responses Of Long-span Concrete Filled Steel Tube Arch Bridge

Concrete filled steel tube arch bridge is a kind of steel concrete composite structure. In this structure, the steel tubes are filled with concrete. The radial confinement of the steel tube limits the expansion of the concrete, and the concrete is in the three direction compression state, then the compressive strength of concrete and the ability of bridge crossing are significantly improved. Basing on Hejiang bridge and the finite element software ANSYS, a series researches on the bridge are carried out, including the simulations on the static, dynamic load tests, dynamical characteristic analysis and seismic response analysis:1. Simulation on the static load test of the approach bridgeBy using the ANSYS software, the author first carried out a simulation on the static load test of the approach bridge, and mainly focusing on the analysis of the vertical deflection of the structure and longitudinal stress distribution.2. Simulation on the static load test of the bridgeBy using the ANSYS software, the author then carried out a simulation on the static load test of the main bridge, and mainly focusing on the analysis of the vertical deflection of the structure and principal stress distribution.3. Dynamical characteristic analysis and dynamical responses analysis undergoing moving loadsBy using the ANSYS software, in the 5th chapter, the author first carried out a research on the dynamical characteristic analysis, mainly on the mode shape and natural frequencies. Then, a set of numerical simulations on dynamical analyses while the structure is undergoing moving loads are carried out, the value of the loads are considered to be constant and variable. In these simulations, the author focused on the vertical deflections over time and also the peak values at the mid-span position of the main arch and the bridge deck. More over, the relationship among suspension stiffness of the moving car, moving speed of the car and the dynamical vertical deflection is researched.4. Seismic response analysis of the bridgeIn the 6th chapter of the paper, the author carried out a research on the seismic responses analysis of the main bridge while undergoing earthquakes. First, the theory on the power spectrum density function of the seismic wave is introduced, and then three waves are introduced including Qianan wave, El wave and one artificial wave, which are used as the input loads for the bridge. In the simulation, the paper concentrates on the relationship between the spectral components of seismic waves and the dynamical response of the structures.