Design of concrete-filled steel tubular columns using data-driven methods

By leveraging the merits of structural steel and concrete materials, concrete-filled steel tubular (CFST) struc-tures have been increasingly used in the composite construction of bridges and high-rise buildings. However, their design equations are more complicated than those of steel and reinforced concrete (RC) structures, especially for circular columns under eccentric loading. Therefore, the use of emerging data-driven approaches will help structural engineers ease the design process. This paper explores the use of data-driven design methods as alternatives to conventional mechanics-based design models. Five boosting algorithms, including adaptive boosting (AdaBoost), gradient boosting machine (GBR), extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), and categorical gradient boosting (CatBoost), are employed to develop predictive models for four different types of CFST columns (i.e., circular columns, rectangular columns, circular beam-columns, and rectangular beam-columns). These predictive models are trained using the most up-to-date and comprehensive database collected from over 3,200 test specimens. Reliability analysis is conducted to calibrate the resistance reduction factors for three different design frameworks (i.e., the US, Eurocode, and Australian frameworks) to ensure that the newly developed predictive models meet the target reliability indices required by different design frameworks. A web-based design tool is also developed to promote the practical use of data-driven methods for the design of CFST columns.