parameter

Steel box girder introduction

Steel box girder, also called steel box girder, is a common structural form of long span bridge. Generally used in Bridges with large spans, it is called steel box girder because it looks like a box.

Characteristic

In the long-span cable-supported bridge, the span of the main girder of the steel box is hundreds of meters to thousands of meters. It is generally divided into several beam sections, which are manufactured and installed. The cross section has the characteristics of wide width and flat shape, and the ratio of height to width reaches about 1:10.

The composition of steel box girder

Generally, steel box girder is connected by the top plate, bottom plate, web plate, diaphragm, mediastinum plate and stiffener through all welding. The top plate is an orthotropic bridge panel composed of a cover plate and a longitudinal stiffener.

The thickness of each plate of a typical steel box girder can be: the thickness of the cover plate is 14mm, the thickness of the longitudinal U-shaped rib is 8mm, the width of the upper mouth is 300mm, the width of the lower mouth is 170mm, the height is 280mm, and the spacing is 620mm. The bottom plate is 10mm thick, and the longitudinal U-shaped stiffener ribs; Oblique web thickness 14mm, middle web thickness 9mm; Diaphragm spacing 4.0m, thickness 12mm; Beam height 2 ~ 3.5m.

Steel box beam is a common structural form used in engineering. In order to study the influence of diaphragms spacing on the distortion of simply supported steel box girder under concentrated load, the distortion effect and rigid torsion effect of simply supported steel box girder with different number of diaphragms were compared under concentrated load, and the curve of maximum distortion effect with the number of diaphragms was obtained. The concentrated load is applied to the top of the box girder web, and the load decomposition method is used to calculate the four working conditions: distortion, rigid torsion, symmetrical bending and eccentric load.