Deformation capacity of flexural-controlled SRC columns under lateral cyclic load

Steel reinforced concrete (SRC) columns are widely used in high-rise buildings of earthquake prone regions. Fewer studies have been carried out on the estimation method of deformation capacity for flexural-controlled SRC columns, which is vital for the seismic evaluation. In the paper, 110 SRC columns with a failure domi-nated by flexural effect were collected from literatures to establish a test database firstly. The data of yield rotation and ultimate rotation of column specimens were extracted from the backbone curves. Then, an analytical method to predict the yield rotation was developed based on the classical model for flexural -dominated RC columns, showing a reasonable accuracy. The influences of shear-span ratio, axial load, steel shape ratio, transverse reinforcement, total longitudinal bar ratio and concrete compressive strength on the ultimate rotation were discussed with the test results of database specimens. Based on the parameter study, an empirical equation, related to shear-span ratio, axial compression ratio and concrete compression strength, was proposed via the regression analysis. In addition, the machine-learning methods, including the artificial neural network and support vector machine, were adopted to evaluate the accuracy of proposed empirical equation further. Finally, some useful recommendations were provided for the seismic evaluation of SRC columns.