Optimized calculation of bearing capacity of short columns of steel-tube-concrete hybrid structures combined with genetic algorithm

Qingyun Ge1, Jing Zheng1, Fulian Yang1, Caimei Li 2
1School of Architecture and Civil Engineering, West Anhui University, Lu’an, Anhui, 237012, China
2Gates Winhere Automobile Water Pump Products (Yantai) Co., LTD., Yantai, Shandong, 712000, China

Abstract

This research proposes a new optimization technique for reinforcement concrete filled structural tubular columns using genetic algorithms and unified strength theory. A complete theoretical model to determine the axial bearing capacity of reinforced CFST columns incorporating modified confinement coefficients and enhanced steel section properties was developed. The optimization procedure deals with performance of the structure, materials usage and construction convenience as the optimization goals. Experimental validation for ultimate bearing capacity of five full scale specimens was carried out and the deviation was found out to be 5.2% which was found to be predicted by the theoretical model accurately. Internal stiffeners are likely to increase axial capacity by about 15.7%-23.4% over traditional CFST columns. The relationship between stiffener parameters and performance of the structure was found to be critical with optimal height to thickness of the stiffener to be in the range of 30 to 45 and space to diameter ratio no greater than 0.5. The problem sets out such mathematics as is nowadays simply necessary for the modern construction world to have at their disposal, as well as reasons for designing reinforced CFST columns.

Keywords: Concrete-filled steel tubular columns, Internal stiffeners, Genetic algorithm, Unified strength theory, Optimization, Bearing capacity, Composite structures