Analysis of Static Characteristics of Steel Box Girder Bridge being composited High Strength Concrete at the Lower Flange of the Support

The steel box girder bridge has excellent applicability to curved bridges owing to its large torsional rigidity. In addition, because the weight of the segments is smaller than that of concrete bridges, it also has many applications for medium-range bridges. However, when a bridge with a span greater than 70 m is constructed, the height of the steel box girder increases, which is disadvantageous for the manufacture and transportation of girders and for bridge construction. Therefore, improvements in the construction methods are required to facilitate construction. Therefore, a structural system of a double composite box girder bridge with an upper slab and composite high-strength concrete at the lower flange of the support of continuous span was proposed, and the structural performance was verified by finite element analysis and a static loading test of an actual specimen. It was confirmed that such a structure minimizes the height of the girder of continuous support by optimizing the sectional efficiency and also improves usability.

Research on the Overall and Local Mechanical Behaviors of Steel Box Girder Cable-Stayed Bridge via Incremental Launching Construction

<p>In this paper, a large-span cable-stayed bridge with double pylons and double cable planes is employed to study the overall and local mechanical behaviors. The steel box girder bridge is constructed by incremental launching with the maximum span of 50 m. Through the overall stress analysis, the most unfavorable stress position of the structure in the incremental launching construction is identified; the refined local stress analysis is carried out for the girder section at this position, and the local stress characteristics of the structure are studied. The mechanical performance and the applicability of incremental launching are determined by comparing four kinds of elastic cushion. This paper aims at improving the safety of incremental launching construction of steel box girder bridge, and can provide reference for similar projects.</p>