Connections And Components Of Hefei Xinqiao International Airport Terminal Steel Structure

Hefei Xinqiao International Airport terminal is a steel structure consistsof large-span rigid frames, which are arranged in the shape of sector along theradial direction. This paper focuses on the bearing behaviors of curvedbox-girders and truss-to-box girder connections at the both ends of the steelframe. Three box-girder model experiments (two of them were scale models,the thied was full scale) and two truss-to-box girder connection modelexperiments (one of them were scale models, the other was full scale) werecarried out under tensile and compressive static load by way of a single jack.Based on the bearing behavior tests on the key connections and components,finite element analysis, parametric anasysis and unified formula for designwere carried out. This paper presents the load-carrying capacity of the curvedbox-girders and truss-to-box girder connections. Unified formula for thein-plane stability of curved box-girder is proposed to guide the design. Thesuggestions for truss-to-box girder connection are put forward as well.(1) The stress state of the structure and components was obtained byanalysis of the whole structure and single frame models. Aiming at the type ofthe cross section, thickness of the steel plates and curvature of the beam axis,parametric analysis was carried out to evaluate the ultimate bearing capacityof this kind of curved box-girder. Design recommendations are presented forthe truss-to-box girder connections.(2) Through the experiments of the curved box-girders (XQL-1, XQL-2and XQL-3), bearing capacity and failure mode under the compression andbending load were obtained. The failure mode of the box girders is the innerflange or web buckling damage after the maximum internal force of sectionreached the yield stress. (3) Considering the initial defects in components, FEM results agreeswell with the experimental results, the ultimate bearing capacity, respectively,have a difference of14.7%,0.8%and2.0%, which shows a very wellsimulation of the tests. Besides, numerical analysis was carried out on the inplane stability of the both ends hinged arc curved box-girder, and an unifiedformula was given. It can be seen from the analysis that the initial processingand transport defects have a certain impact on the bearing behavior of thecurved box-girders.(4) Through the experiments of the truss-to-box girder connections(ZHJD-1and ZHJD-2), bearing capacity and failure mode were obtained. Thescale model (ZHJD-1) was in a brittle failure state with weld fracture. And thefull scale model (ZHJD-2) was with a compression buckling damage in thetube.(5) Considering the initial defects in components, FEM results agreeswell with the experimental results, the ultimate bearing capacity, respectively,have a difference of-1.8%and5.5%. It can be seen from the analysis that thetruss-to-box girder connectios are ensitive to the initial defect. Ends of thebottom chord pipe, connecting of top chord pipe and the rectangular tube, aswell as the three-dimensional truss pipe joints have a high level of stress. It isproposed to add in local short-stiffeners to avoid stress concentration, and todo some local strengthening for the large axial compression members to avoidbuckling failure.