Flexural behaviour of horizontally curved I-girders with round concrete-filled tubular flange

The flexural behaviour of the simply supported individual curved round concrete-filled tubular flange girders (CRCFTFGs) and the corresponding curved I-girder (CIG) under concentrated load at mid-span is investigated experimentally and analytically. Two CRCFTFG specimens and one CIG specimen are considered in this study. One of the CRCFTFG specimens is designed with a pair of transverse stiffeners at mid-span. The other one has uniformly arranged seven pairs of transverse stiffeners along the girder span. These specimens are denoted as CRCFTFG-1 and CRCFTFG-2, respectively. A special rolling track device is designed to ensure that the load is in the vertical direction during the test. In the experiment, the failure mechanism of three specimens and the development of strain and displacement with the vertical load at certain critical positions are measured and analysed in detail. Experimental results show that increasing the number of transverse stiffeners can effectively avoid web distortion and enhance the load carrying capacity of CRCFTFGs. CRCFTFGs have much larger load carrying capacity and smaller lateral displacement and cross-sectional rotation than CIG. The finite element (FE) analysis is used in the numerical analysis to model the test specimens. The comparison outcome between the FE models and the experimental results indicated that they are in reasonably good agreement. A parametric study is conducted based on the validated FE models to investigate the influence of initial geometric imperfections, web distortion, the ratio of span to curvature radius (L/R) and the infilled concrete on the load carrying capacity of CRCFTFGs.