The Finite Element Method And The Side Of The Bridge Of Dashengguan Changjiang River Bridge Study On The Calculation

Nanjing Dashengguan Yangtze River Bridge is a large-sized 6-line railway project designed for Beijing-Shanghai High-speed Railway and Shanghai-Hankou-Chengdu Railway. The Side bridge of shallow-water zone is designed as double-span [(84+84) m] continuous steel truss structure while the main bridge is six-span[(108+192+336+336+192+108) m] continuous steel braced arch, which is three main trusses and the whole-involved steel-bridge-floor structure with upper flanges of lower chords, longitudinal girders, transverse girders as parts of the deck slab. This paper made a research on the finite element analysis method of the Bridge while applying the results to analysis and calculation of the side bridge. The main research achievements are as the followings:1．A Space Plate-Beam model based on the space finite element analysis was formulated, adopting space-beam elements for members of the main truss and longitudinal girders, transverse girders, stringers of the bridge deck system members, and also using shell elements for the steel bridge deck slab, in accordance with features of the Bridge.2．The affects caused by shearing deformations to the deformations and load-carrying conditions of lower chords, longitudinal girders, transverse girders, and the comparison analysis between the beam and shell elements of the members, come to a conclusion: Shearing deformation had relatively significant affects on deflection for the short shear spans of lower chords, Longitudinal beams, and transverse beams as well as high beam depth.3．Through a research on some space issues, such as adoptions of sections of lower chords, longitudinal girders, transverse girders under the finite element analysis, and the connecting ways of the bridge deck slab, by comparing and analyzing the test and results of the 4 models with careful consideration on the relevant factors including accuracy, rate, and calculation scale, one of the 4 analysis methods was selected to apply in the whole bridge.4．The analysis and calculation for the 2×84m side bridge under 1st-stage dead load, 2nd-stage dead load and live load conditions were completed by the selected method mentioned above.5．The influence line loading calculation of members of lower chords, longitudinal girders, transverse girders of the bridge deck system, and the load-carrying condition analysis under the situation with the most unfavorable load combination were completed.It finally came up with a conclusion that both strength and stiffness of the side bridge meet the relevant requirements.The results provide a mathematical foundation for the design of the side bridge. The space plate-girder method is also applicable to the analysis and calculation of the main bridge or other similar structures.