Study On Seismic Behavior Of Concrete Filled Steel Tubular Arch Bridges Based On OpenSees

With the high bearing capacity, strong spanning ability, good seismic behavior and convenience of construction, concrete filled steel tubular (CFST) arch bridges develop rapidly. As China is a country with earthquakes often-occurred, under the present conditions that CFST arch bridges have been widely used, studying on the seismic behavior is very necessary and urgent. OpenSees (Open System for Earthquake Engineering Simulation) is a computational platform for seismic response simulation developed by University of California at Berkeley. Its key feature is open source and framework. Users can apply and develop it by the Internet; this can happen at a speed the development. It is a new concept different from the conventional software development. The computational precision of elastic-plastic time-history analysis of CFST arch bridge depends on constitutive relations of materials. There have been many constitutive relations of core concrete. In this paper, several typical constitutive relations of core concrete are compared, Push-over analysis of a CFST short column is carried out by using OpenSees to select the constitutive relation for the research. A test model CFST arch bridge is simulated by using OpenSees to determine dynamic analysis model. The computation results have a good agreement with the test measures. Finally, Wuxia Changjiang Bridge is analyzed under some earthquake records and seismic responses along the arch rib are obtained. Based on the analysis of these seismic responses, some regularities of CFST arch bridge under earthquake loading are studied. It will benefit the seismic concept design and the foundation of seismic design theory in CFST arch bridges.