Failure mode classification of reinforced concrete column using Fisher method

QI Yong-le(戚永乐)^{1. 2}, HAN Xiao-lei(韩小雷)², JI Jing(季静)²

(1. Guangdong Electric Power Design Institute, China Energy Engineering Group Co. Ltd., Guangzhou 510663, China;
2. School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China)

Abstract:In order to apply the performance-based seismic design, an engineer must ？rst find out whether the column is expected to fail in shear before or after ？exural yielding. According to column failure characteristics and failure mode of reinforced concrete column, the UW-PEER structure performance database was discussed and analyzed. In order to investigate the relevance of failure mode and factors such as longitudinal reinforcement ratio, transverse reinforcement ratio, hoop spacing to depth ratio, aspect ratio, shearing resistance demand to shear capacity ratio and axial load ratio, Fisher’s discriminant analysis (FDA) of the above factors was carried out. A discriminant function was developed to identify column failure mode. Results show that three factors, i.e., V_p/V_n, hoop spacing to depth ratio and aspect ratio have important influence on the failure mode. The failure mode has less to do with longitudinal reinforcement ratio, transverse reinforcement ratio and axial load ratio. Through using these three factors and the model proposed, over 85.6% of the original grouped cases were correctly classified. The value of coefficient of V_p/V_n is the largest, which means that discriminant equation is most sensitive to the shearing resistance demand to shear capacity ratio.

Key words:Fisher’s discriminant analysis (FDA); concrete column; failure mode identification; performance-based seismic design