Study on A New Type of Deck Applied to Four-lines Railway Cable- stayed Bridge with Wide Truss Stiffening Girder

A cable-stayed bridge, whose main span is 230 m, is a four-line railway steel truss bridge. It is the first time to use only two main trusses in four-line railway truss bridge. In order to solve the transfer problem of wide truss-deck system and the design of the horizontal deck-beam, auxiliary longitudinal beams and horizontal K-bars are installed near lower chords of main truss. This is an innovative deck system, and we need to research on the structure performance. In this paper, the comparative analysis between the new type of deck system with horizontal K-bars and the traditional deck system with multi-crossbeam were carried out by FEM which focus on the deck structural characteristics, system stiffness, local deformation, etc. Also, in order to carry out the model test, a scale segmental experimental model of deck structure with horizontal K-bars was designed and manufactured. The FEM results show that: the bridge deck system with horizontal K- shaped braces is better than the multi-crossbeam deck system in structural stiffness, local deformation, participating rate of longitudinal force. And, the experimental results were in good agreement with the results of FEM analysis, which verified the correctness of FEM results and the rationality of design. The working condition of the bridge is good since opened on December 26, 2014.