关键词: 桥梁工程, 悬索加劲连续钢桁梁, 板桁结合钢桥面板, 静力受力行为, 多尺度有限元模型

Abstract: In order to investigate the static force behaviour of special joints at the connection between the top chord and stiffening chord of plate-girder combined continuous steel truss girder stiffened by suspension cables, a three-dimensional multi-scale finite element model of the whole bridge was established, which was based on Chongqing Zengjiayan Jialing River Bridge. The results of finite element analysis were verified by the scaled model test, and the stress condition of special joints under the most unfavorable load combination was studied. The research results indicate that the stress near the connection between the stiffening chord and the top chord is relatively large and its distribution is complex, which is the focus of the study. The Von Mises stress of the majority of special joints is below 198.0 MPa. The Von Mises stress of each member of the special joint is less than the strength design value of the steel, and the structure has sufficient safety reserves. The orthotropic steel deck participates in the vertical bending of main girder. The internal forces transmitted by the upper deck system account for about 34% and 33% of the combined forces in the longitudinal and transverse directions. The load is transferred from the midspan to the fulcrum through the special joint, and the force borne by the steel deck, top chord, vertical web and diagonal web is gradually transferred to the stiffening chord. The stiffening chord is introduced to improve the beam height and resist the vertical bending moment of the main beam section. Results of finite element analysis verify the reliability of the special joints of the Zengjiayan Jialing River Bridge, which can also serve as a reference for future research and design of similar structures.

Key words: bridge engineering, continuous steel truss girder stiffened by suspension cables, plate-truss composite steel deck, static force behaviour, multi-scale finite element model