Seismic Performance Of RC Frames With Centrally Reinforced Columns

China is situated between two most active seismic zones in the world, with its east in thecircum-Pacific seismic belt, the west and southwest in the Eurasian seismic belt, so that it isone of the world’s most earthquake-prone countries. Each earthquake will cause the collapseof a large number of buildings and huge losses of people’s lives and property. Due to itsflexibility in plane layout and ease in forming a large space, the concrete frame structure hasbeen very widely used in many buildings in China. In order to ensure the concrete framestructure with sufficient seismic capacity, designers often provide the frame with sufficientductility, that is to say, the structure can be resistant to earthquakes with plastic deformation tomeet the requirements of buildings’ survival even during major earthquakes. In The Code forSeismic Design of Buildings, the frame column ductility is mainly improved by the way oflimiting column axis compression ratio and other measures while CRC（centrally reinforcedcolumns）can reduce the axial compression ratio. Studies have shown that the CRC has goodhysteresis ductility and high seismic capacity with reasonable proportion. Therefore, it isnecessary to study the seismic performance of the frame structure composed of CRC.This paper gives an analysis of push-over under such different conditions as frequentoccurrences, fortification and rare earthquakes by setting the same seismic performance goalsfor a frame structure with ordinary concrete column and with relevant CRC. By analyzing andcomparing the base shear-top displacement curve, capacity spectrum-demand spectrum curve,the floor displacement, inter-story drift and the development and distribution of the plastichinge at the performance point, it is assessed whether the carrying capacity and deformationcapacity of the structural members can reach the design specifications of differentanti-seismic levels so as to confirm whether the overall structure can meet the requirements ofbuildings’ survival even during major earthquakes. Accordingly, the paper further evaluatesthe overall seismic capability of CRC frame structure in an objective and reasonable way inorder to provide theoretical and technical support for its promotion and application. Resultsindicate that in the case of significantly reduced section of CRC, the overall carrying capacityand seismic performance are still higher than a frame structure with ordinary concretecolumn.