Views: 0 Author: Site Editor Publish Time: 2024-09-27 Origin: Site
Steel box beam （Steel structure fabrication）, also known as steel box girder bridge, is a commonly used structural form for long-span bridges. Typically adopted in bridges with large spans, it is named steel box girder due to its box-like shape.
In large-span cable-supported bridges, the span of the steel box girder bridge can reach hundreds of meters to even kilometers. It is generally manufactured and installed in several segments, featuring a wide and flat cross-section with an aspect ratio of approximately 1:10. The steel box girder bridge is typically constructed by fully welding together a roof plate, a bottom plate, web plates, transverse diaphragms, longitudinal diaphragms, and stiffening ribs. The roof plate constitutes an orthotropic deck plate composed of a cover plate and longitudinal stiffening ribs. Typical thicknesses for various plates in a steel box girder are: cover plate thickness of 14mm, longitudinal U-shaped rib thickness of 6mm with an upper width of 320mm, a lower width of 170mm, a height of 260mm, and a spacing of 620mm; bottom plate thickness of 10mm with longitudinal U-shaped stiffening ribs; inclined web plate thickness of 14mm, middle web plate thickness of 9mm; transverse diaphragms spaced at 4.0m intervals with a thickness of 12mm; and a beam height ranging from 2 to 3.5 meters.
High precision and accuracy in design and manufacturing. Thanks to the high strength and stability of steel, steel box girder bridges exhibit excellent resistance to deformation and have superior load-bearing capacity.
Enhanced convenience during construction and installation. Compared to other bridge structures, steel box girder bridges have lower manufacturing costs and shorter production cycles.
Good durability and reliability. Steel's strong corrosion resistance effectively withstands chemical and physical erosion.
Detailed design precedes the production of steel box girder bridge. Designers determine the dimensions, shapes, and materials of steel box girder bridge based on bridge requirements, considering load conditions, lateral and longitudinal deflections, and ensuring safety and reliability.
Material preparation: Steel plates are prepared as raw materials for the steel box girder bridge. Plates of appropriate size and thickness are selected according to design specifications.
Plate fabrication: Steel plates are cut, bent, and processed according to design drawings to produce steel box plates that meet requirements.
Welding: Fabricated steel box plates are welded together to form the cross-section of the steel box girder bridge.
In June 2018, EVERCROSS BRIDGE TECHNOLOGY (SHANGHAI) CO.,LTD. undertook the construction of a 34-meter single-span steel box girder bridge in Wuhe County, Anhui Province, using the segmented lifting method for installation.
l Xuanmen Bay Bridge Tributary Trough Beam Project:
The main bridge of Xuanmen Bay Bridge is a single-pylon spatial double-cable-plane cable-stayed bridge with a "moon ring" + H-shaped steel tower. The main girder employs a steel-concrete composite beam, while the foundation adopts a pile group + pile cap structure. The approach bridge utilizes prestressed concrete cast-in-place box girders. The upper structure of the tributary viaduct employs a steel-concrete composite beam with a steel trough beam as the main girder, topped with a bridge deck as the load-bearing structure. The main girder adopts a double steel trough box composite beam with a full-width deck of 19.5m (varying from 19.5m to 20.5m in width-changing sections). The horizontal center-to-center spacing of steel trough boxes is 10m, and the beam height is related to the span. Our company undertook the production of approximately 6,000 tons of steel trough beams for this project.
