Product Overview
Steel Box Girder is a torsionally efficient fabricated bridge girder assembled from steel plates, diaphragms and stiffeners. It is supplied as a project-specific solution rather than a fixed catalogue item. Geometry, member sizes, connections, protection systems and delivery segmentation are confirmed from approved documents.
The engineering and fabrication scope can coordinate bridge deck, bearings, field splices, drainage and erection equipment. Early review of drawings, loads, site conditions and transport limits helps define a practical supply package and reduces interface risk.
Product Core Parameters
| Product type | Steel Box Girder |
|---|---|
| Primary configuration | torsionally efficient fabricated bridge girder assembled from steel plates, diaphragms and stiffeners |
| Engineering basis | Approved project drawings, loads, site conditions and applicable codes |
| Dimensions / span | Project-specific |
| Material grade | Defined by approved design and procurement specification |
| Connections | Welded, bolted or combined as detailed |
| Inspection | Approved inspection and test plan; specified NDT where required |
| Surface protection | Selected for exposure, service life and maintenance plan |
| Delivery | Component size, marking and sequence coordinated with transport and erection |
Key Features
- Project-specific engineering: The steel box girder is developed around torsional behavior, plate stability, weld sequencing and sectional geometry; final member sizes and details follow approved calculations and drawings.
- Coordinated interfaces: Design and detailing account for bridge deck, bearings, field splices, drainage and erection equipment, reducing conflicts during fabrication and site assembly.
- Controlled prefabrication: CNC processing, documented fit-up and controlled welding improve dimensional consistency and traceability before shipment.
- Connection detailing: Bolted, welded and bearing interfaces are coordinated with the actual load path, access, tolerances and erection method.
- Inspection planning: Material verification, dimensional checks, weld inspection and specified NDT are tied to the approved quality plan.
- Delivery-ready documentation: Member marks, packing lists, inspection records and erection information are prepared to match the agreed supply scope.
Main Components
The exact bill of materials is project-specific. A typical steel box girder package may include:
- 01 — Top and bottom flange plates: Detailed and fabricated according to its structural function, connection requirements and approved drawings.
- 02 — Web plates and closed box cells: Detailed and fabricated according to its structural function, connection requirements and approved drawings.
- 03 — Internal diaphragms and cross frames: Detailed and fabricated according to its structural function, connection requirements and approved drawings.
- 04 — Longitudinal and transverse stiffeners: Detailed and fabricated according to its structural function, connection requirements and approved drawings.
- 05 — Splice plates, access details and connection assemblies: Detailed and fabricated according to its structural function, connection requirements and approved drawings.
- 06 — Bearing, deck and erection interfaces: Detailed and fabricated according to its structural function, connection requirements and approved drawings.
Typical Applications
01 — Highway and municipal bridges
Suitable where the project requires torsional behavior, plate stability, weld sequencing and sectional geometry. Final suitability depends on loads, geometry, site conditions, interfaces and applicable regulations.
02 — Urban viaducts and curved alignments
Suitable where the project requires torsional behavior, plate stability, weld sequencing and sectional geometry. Final suitability depends on loads, geometry, site conditions, interfaces and applicable regulations.
03 — Rail, transit and industrial crossings
Suitable where the project requires torsional behavior, plate stability, weld sequencing and sectional geometry. Final suitability depends on loads, geometry, site conditions, interfaces and applicable regulations.
Manufacturing & Delivery
- Review bridge drawings, loads, geometry and authority requirements
- Coordinate shop drawings, splices, camber and erection segmentation
- Verify plate grades, traceability and material certificates
- Perform CNC cutting, edge preparation, drilling and machining
- Complete controlled fit-up and welding using approved procedures
- Inspect geometry, welds, bolted interfaces and specified NDT
- Conduct trial assembly or interface checks where required
- Apply the approved bridge coating system
- Mark, pack and deliver by erection segment with quality records
Project Customization
Customization can cover overall geometry, member sections, material grades, connections, openings, interfaces, inspection scope, coating system, fire protection, packing and erection sequence. For a technical review, provide the project location, design basis, drawings, loads, quantities, required standards, inspection requirements, finish and delivery destination.
Quotation input: architectural or structural drawings, dimensional schedule, load criteria, material specification, connection responsibilities, coating requirements, quality documentation and target delivery program.