The Analysis And Research On Force Bearing Properties Of The Plate-truss Composite Structure Stiffened With Cables

The plate-truss composite structure, in which the concrete deck plate and steel main truss co-act together, has come into use in a long span cable-stayed bridge for both highway and railway because of its many advantages. But no references are available about this kind of bridge. Bridge engineers and design department want to comprehensively understand its property of force bearing.This paper uses ANSYS parametric design language and the virtual temperature load method to adjust the tension force in the cable, which unites the computing models before and after adjusting cables, and conveniently takes the influence of all kinds of nonlinear factors into account.In this paper, after a long span cable-stayed bridge with a plate-truss composite beam over main channel of Wuhu Yangtze River Bridge is selected as an example, special finite element method and the ANSYS software are used to analyze spatial force bearing properties under several different loading cases. The results show that: the distributing action between under-bracing and railway deck system is more evident with increment of the rigid of railway transverse beam, which has to be taken into account; the tension force is transferred to main truss mainly through special diagonal web member and batter brace; the mechanic model which can consider secondary stress of truss should be used in the plate-truss composite structure.This paper analyzes the influence of the bending rigid of highway transverse beam, the depth of concrete deck plate and the material nonlinear on the effective deck plate width and draws some important conclusions. This paper proposes the notion of even effective width that can be used into imitation when plane rod finite element method is used to analyze long span bridges.