Big Span And Iron Amphibious Board-Truss Structure Cable-Stayed Bridge Force Performance Analysis

FFW Yangtze River main bridge is a highway-railway cable-stayed bridge composed of combined plate truss structure with twin towers and five spans arranged as60+156+464+156+60m. The upper and lower bridge decks adopt orthotropic steel bridge deck structure with complex stress state. The paper used finite element method to study the mechanical characteristics scientifically, The main work and conclusions are as follows:1. Studied the finite element simulation method for the big span highway-railway cable-stayed bridge composed of combined plate truss structure, established two finite element models for whole bridge using spatial plate-beam method, for the calculation of the dead load, the most unfavorable living load and additional force respectively.2. Studied the mechanical behavior under the dead load, all kinds of most unfavorable living loads and combination of main loads, result shows:the deflection span ratio is1/1441under the most unfavorable living load, the stiffness meets the requirements; The strength and stiffness of elements meet the design standard under all kinds of combination of main loads, the bridge’s whole mechanical performance is good.3. Studied the mechanical behavior under thermal Load, result shows:With the whole bridge temperature’s30degrees’rising or cooling, the the total amount of bridge’s stretch or shrinkage on both ends is32cm, stress of steel components is less than14.0MPa.4. Studied the mechanical behavior under two kinds of wind loads, result shows: The lateral deflection is small under wind loads, the maximum lateral deflection is4.84cm; the stress of steel components is less than13.0MPa.The results of this paper offered basis for the design of FFW Yangtze River Bridge with reference value for other similar highway-railway cable-stayed bridges.