Passenger Dedicated Line 96m Deck Clouds Beam System Simply Supported Steel Truss Girder Bridges Model Test,

For reason of rapid and dense traveling, special line and high-speed railway have high requirements for the bridge in flexural rigidity, torsional rigidity, stability and durability. The deck-through steel truss-concrete deck composite bridge with multi-trtransverse-beams could meet the above mentioned requirements quitely. In this paper,on basis of a deck-through steel truss-concrete deck composite bridge spanning 96m with multi-trtransverse-beams, a 1:6 reduced-scale model was constructed and both experiment and finite element analysis of three model stages were completed. The main work has been done as follows:1. A 1:6 reduced-scale model was constructed according to the similarity theory, moreover the accessorial loading device was designed and fabricated, the loading project of the experiment was decided.2. Both experiment and finite element analysis of several various load cases were completed to the steel model structure,the semi-composite model structure and the completely-composite model structure respectively. The values of displacement and stress of the model experiment accords with those of the finite element analysis relevantly. By analysing the results of both experiment and finite element analysis, the deformation and the mechanical behavior of the three structures were studied.3. The influence of the concrete bridge deck on the mechanical behavior of the bridge was studied. The results show that the concrete bridge deck can enhance the integral rigidity of the structure, and improve the mechanical behavior of the bottom chord and the bridge deck system; for the deck-through steel truss-concrete deck composite bridge spanning 96m with multi-trtransverse-beams, the favorable thickness of the concrete deck is 24～30cm.4. By analysing the experiment results and the theoretical results of the semi-composite model structure and the completely-composite model structure, the compositing the concrete with the bottom chord can reduce the stress on the end of the transverse-beam evidently and which is also some effective on the bottom chord but little on others. 5. The mechanical behavior of the two types of the composite deck system of this kind of truss bridge was studied. The results show that the bottom chord endures vertically bending moment significantly besides axial force, the value of the vertically bending moment is related to the vertical rigidity of both internode-transverse beam and bottom chord. Secondly, the extent of deck system co-acting with the main truss is 26%～33% for the semi-composite model structure and 37%～42% for the completely-composite model structure respectively.The research results of the paper could supply the design consideration for the deck-through steel truss-concrete deck composite bridge spanning 96m with multi-trtransverse-beams and extently for other similar structures.