Experimental Study On Seismic Performance Of Circular Concrete-filled Steel Bridge Columns

Concrete-filled steel tube is a composite structure which is made by steel and concrete, it is famous by high stiffness, ductility, seismic ability, and many other advantages, so it is often used in the bridge piers especially in the Southwestzones. Now few study on the seismic performance of the circular concrete-filledsteel tube which is in the big section size, no matter in the domestic and overseas. The paper based on the tests of the four circular concrete-filled steel tubesunder low reversed cyclic loading, then a preliminary study on the seismic performance of circular concrete-filled steel tubes. Focused on the following aspects:①Tests on the four circular concrete-filled steel tubes in order to study theseismic performance. The four tubes have different set of hoop coefficient andslenderness ratio indexes. Discuss the influence on the performance for the tubes,by comparing the ductility, displacement, energy dissipation capacity and rigiditydegeneration.②The circular concrete-filled steel tubes under low reversed cyclic loading,study the variation law of the vertical strains and lateral strains in the plastichinge regions.③Through the MATLAB software program, based on the fiber model method to calculate the experiment models under the low reversed cyclic loading, comparing the bending moment-curvature and load-displacement skeleton curves with the test results, then find out that the limit horizontal load in the tests and models are similar.④Based on the bending moment-curvature, load-displacement skeleton model from the literature, calculate the bending moment-curvature, load-displacement skeleton curves for the experiment models, comparing the calculation results withthe test results, the calculation results is smaller than the tests with larger security reserves.