Seismic Performance of Reinforced Concrete Pier with Inside Concrete Filled Steel Tube

A reinforced concrete column with inside concrete filled steel tube (RC-CFT) has many advantages over reinforced concrete (RC) column, such as higher compression, shear and moment capacity, higher ductility. So this kind of composite column has been used as frame column in buildings. In this paper, the composite columns are used as piers of a continuous bridge to improve the seismic performance. Using nonlinear time-history analysis method and fiber element model, considering elasto-plastic nonlinearity, the nonlinear relationships between lateral load and horizontal displacement of RC-CFT pier and RC pier are calculated, and the seismic behaviors of continuous bridges with the two types of piers are analyzed. Based on the comparison of the results, it is found that the ductility of RC-CFT pier is much larger than RC pier. Under the same intensity earthquakes, the damage of RC-CFT pier is less than the RC pier, and RC-CFT pier is more safe and easy to be repaired after earthquake.