Study On Caculation Method And Mechanics Properties Of Through Steel Truss Composite Bridge

Through steel truss composite bridge is a new-type bridge structure, which hasmany advantages such as large bending and torsional stiffness, low constructuralheight, low noise and vibration in train driving and high comfort degress etc. In thispaper, FEM calculation method and stress condition about this type bridge areanalyzed, the main works been done as follows:1. A smiple and effective FEM model of this type bridge is presented, it cansimulate slips and lifts between concrete slab and the steel beam. Compared with fullshells model simulating whole bridge or full bridge decks, it needs less degree offreedom and computer-time comsumtion.2. The FEM model of some through steel truss composite bridge are constructedand analyzed the mechanics behavior of the bridge subjected to general load cases,besides qualitative explanation is provided.3. Shear lag effect of concrete slab is analyzed, the calculation results show thatthere is a evident positive shear lag effect at the point of internode mid-span andnegative shear lag effect commonly appeared in negative moment area.4. Longitudinal force's distribution between bridge deck system and bottomchord of girder is deeply analyzed, the calculation results show that proportion oflongitudinal force shared by bridge deck system is about 10％～20％. Longitudinalbending stiffness of crossbeam and longitudinal axial stiffness of bridge deck systemcan also effect the longitudinal force's distribution between bridge deck system andbottom chord of girder.5. How effect thickness change of concrete slab the stiffness of the structure,inner forces of girder, stress in concrete slab and longitudinal force's distributionbetween bridge deck system and bottom chord of girder are also analyzed and someuseful conclusions are gotten.6. How effect different connecting stiffness and changing interspace betweenshear connectors the bridge are discussed and some general conclusions are putforwared.7. Study on mechanic properties between complete combination and partialcombination bridges, and analyse and compare affects which different combination of concrete slab and steel girder complete combination bridge part has on bridges.