Steel Bridge Structures
Steel bridge structures fabricated to your bridge engineer’s design: plate girder and welded box girder bridges, steel truss bridges, pipe truss arch bridges, steel-concrete composite girders and portal frame bridges. Girders and truss panels are made in transport-length segments with shop-fitted splices, welded and tested to AWS D1.1 or the EN 1090-2 EXC2 requirements your specification names.
What This System Includes
The component families we fabricate in-house for this product line. Send a BOQ and we quote against these directly.
I/H Beam Simply Supported Bridges · Welded Box Girder Bridges · Steel Truss Bridges · Pipe Truss Arch Bridges …
Technical Specifications
| Item | Specification |
|---|---|
| Design basis | EN 1993-2 / AASHTO LRFD, as the project specifies; bridge design stays with your engineer |
| Execution class | EN 1090-2 EXC2 (certificate 2787-CPR-01627) |
| Steel grades | S355 / S460 to EN 10025, ASTM A36 / A992, with EN 10204 type 3.1 mill certificates traced to heat number |
| Welding | AWS D1.1 / EN ISO 9606 qualified procedures and welders; full-penetration flange and web welds |
| NDT | 100% UT or MT on critical full-penetration welds, radiographic testing where the specification names it |
| Fatigue details | Detail categories per the bridge design code your engineer specifies; weld profiles and run-off treatment per drawing |
| Splices | Shop-fitted splice plates with match-marked holes; HSFG assemblies to EN 14399 / ASTM F3125 |
| Trial assembly | 1:1 physical trial assembly in the yard to AISC / EN 1090-2 practice: bolt hole groups checked for at least 95% free entry, span, camber and node coordinates held within ±2.0 mm, with a dimensional report and photographs before coating. |
| Corrosion protection | ISO 12944 system for the crossing environment |
| Documentation | MTRs, WPS/PQR, welder certificates, NDT, DFT and trial assembly reports with every shipment |
Project-specific tolerances, section sizes and load tables are issued with the quotation once your design basis is received.
Advantages vs Engineering Considerations
| Advantages | Engineering Considerations |
|---|---|
| Segmental fabrication planned for transportEvery girder and truss is split at the drawing stage into segments that fit containers or flat racks, with splice plates and bolt holes shop-fitted and match-marked. | Fatigue governs many details; connection categories and weld quality must follow the bridge code. |
| Full-penetration welds testedFlange and web welds are made to qualified procedures and tested by ultrasonic or radiographic methods as the specification requires, with a report per weld. | Transport and launching or crane capacity often dictate segment lengths and splice positions. |
| Trial assembly before shippingTruss and arch bridges are trial-assembled in the yard with dimensional reports and photographs so site fit-up is verified before the steel leaves. | Corrosion protection for bridges is heavier and needs maintenance access planned from the start. |
| Coating for the crossingISO 12944 systems applied after shot blasting to Sa 2.5 with dry film thickness records. | Bearings, expansion joints and deck interfaces must be detailed together with the steelwork. |
Certifications & Compliance
Every shipment leaves with the documents an auditor asks for. Scroll the row and open any certificate at full size.
China Steel Structure Manufacturing Grade I
AISC Certification
CE Marking – EN 1090-2 (CPR 01627)
OTC Document of Validity
International Welder Certification
Enterprise Qualifications Portfolio
DG Packaging Certificate
Labor & Scaffolding Contracting
Explosion-Proof Certificate
Industrial Pipeline Installation GC1
Power Facility License
Have drawings or a BOQ ready? Send them through the form and our engineers reply with a preliminary assessment.
Related Projects
Steel structures we fabricated and shipped for the same kind of building.
SynJect. Scale. Precision. Certainty.
SYNJECT delivers comprehensive steel structure solutions engineered for the global value chain. From investors seeking ROI to engineers demanding exact compliance, we transform complex blueprints into robust realities—on time and without friction.
SynJect ENGINEERING
From Microns to Megastructures — 12 Rigorous Stages Certified to AISC & EN 1090
Detailed Engineering & Shop Drawing Development
Utilizing advanced BIM platforms such as Tekla Structures, detailed 3D modeling and shop drawings are executed strictly in compliance with AISC 360 or Eurocode 3 (EN 1993). Connection designs are rigorously verified, with manufacturing drawings generated to ISO 2768-m tolerance standards. 100% clash detection with primary architectural and MEP systems is performed to ensure zero structural conflicts during field erection.
Nesting & Material Optimization
Intelligent nesting layouts are performed using advanced software like FastCAM/SigmaNEST in accordance with EN 10029 / ASTM A6 dimensional standards. Accounting for cutting kerf (2mm-5mm depending on plate thickness) and thermal contraction allowances, raw material utilization exceeds 92%. Offcuts are digitally barcode-tracked to ensure 100% mill test report (MTR) traceability.
Raw Material Incoming Inspection
All structural steel (Q355B/C/D, ASTM A572 Gr.50, S355JR/J2) must be accompanied by EN 10204 3.1 Mill Test Reports (MTR). Incoming quality control conducts 100% dimensional and visual inspections under ASTM A6 / EN 10029, verifying thickness tolerances (Class A/B) and internal lamination integrity via Ultrasonic Testing (UT) to ASTM A435. Chemical composition and mechanical properties are spot-verified by accredited 3rd-party labs.
CNC Cutting & Edge Preparation
Plate profiling and component cutting are executed via CNC oxy-fuel, high-definition plasma, and multi-kW fiber laser equipment. Cut surface quality strictly complies with EN ISO 9013 for perpendicularity and surface roughness (Range 3/4 tolerance). Multi-axis CNC beveling machines execute weld prep bevel angles within ±2.5° and root face dimensions within ±1.0 mm.
Primary Structural Welding
Welding is performed exclusively by AWS D1.1 or EN ISO 9606 certified welders using qualified Welding Procedure Specifications (WPS) supported by Procedure Qualification Records (PQR) per AWS D1.1 / ISO 15614. Submerged Arc Welding (SAW) and Flux-Cored Arc Welding (FCAW) dominate Complete Joint Penetration (CJP) and fillet welds. Heat input is strictly controlled, achieving weld quality levels conforming to ISO 5817 Quality Level B or AWS D1.1 standards.
Weld Distortion Straightening
Post-weld angular distortion, camber, and sweep are rectified using automated hydraulic flange straighteners and controlled thermal flame straightening. Heating temperatures for High-Strength Low-Alloy (HSLA) steels are strictly maintained between 600-650 Celsius (air-cooled, zero water quenching) to prevent microstructural degradation. Post-straightening straightness tolerances meet ±3 mm, conforming to EN 1090-2 Execution Class 2 (EXC2) and AISC COSP standards.
Non-Destructive Testing (NDT)
NDT protocols are operated by ISO 9712 / ASNT Level II certified NDT personnel. 100% of critical Complete Joint Penetration (CJP) welds undergo Ultrasonic Testing (UT per ISO 17640 / ASTM E164) or Magnetic Particle Testing (MT per ISO 17638 / ASTM E709). Radiographic Testing (RT) is applied as requested for heavy sections. Weld acceptance conforms strictly to ISO 11666 Acceptance Level 1 or AWS D1.1 criteria.
Trial Assembly & Shop Alignment
Complex geometries, long-span trusses, and heavy framing undergo 1:1 physical trial assembly or high-precision 3D laser scanning virtual assembly per EN 1090-2 / AISC requirements. Bolt hole alignment is verified (≥95% free-pass rate for high-strength bolts), and critical dimensions (span, camber, 3D spatial alignment) are verified within tight tolerance limits (±2.0 mm) to eliminate site fitting risks.
Surface Preparation & Protective Coating
Structural members undergo automated shot blasting to achieve SSPC-SP10 / NACE No. 2 / ISO 8501-1 Sa 2.5 cleanliness, with a surface profile (anchor depth) of 45-75 microns. High-performance protective coatings are applied using airless spray technology in compliance with ISO 12944 (C3 to CX corrosive environments), featuring Zinc-Rich Epoxy Primers, Epoxy Micaceous Iron Oxide Intermediate coats, and Polyurethane/Fluorocarbon Topcoats. Dry Film Thickness (DFT) is verified adhering strictly to the 90/10 rule.
Final Quality Inspection & Certification
Final Quality Control (FQC) performs a comprehensive audit, inspecting paint aesthetics (zero runs, pinholes, sagging), critical geometry, bolt hole pitches, and component mark traceability. A complete Manufacturing Data Report (MDR) comprising MTRs, NDT records, coating inspection logs, and Certificates of Conformance is compiled to support CE Marking (DoP under EN 1090) and AISC final acceptance.
Export Packaging & Logistics Protection
Protective packaging is engineered for containerized (40HQ/OT/FR) and breakbulk ocean freight under heavy maritime transit conditions. Structural members are bundled on heavy-duty steel skids with high-tensile steel strapping. Machined connections are wrapped with VCI anti-corrosion film, EPE foam padding, and heavy rubber cushions. All timber packing complies fully with ISPM 15 phytosanitary standards and IMO Cargo Stowage and Securing (CSS) rules.
Global Field Erection & Site Management
We deliver international site erection supervision and turnkey EPCM construction services adhering to OSHA 1926 safety protocols, AISC COSP, and EN 1090-2 erection standards. Field teams, led by multilingual HSE and QA/QC engineers, utilize high-precision total stations to maintain structural plumbness within H/1000 (25mm max). High-Strength Structural Bolting is executed via calibrated Wrench or Turn-of-Nut methods with 100% torque audit documentation.
Frequently Asked Questions
Can you fabricate a steel pedestrian bridge or footbridge as a pipe truss arch?
Yes. Send the span, deck width and the bridge engineer’s drawings. We fabricate the tubular arch, deck framing and railing supports in transport-length segments, with trial assembly before shipping.
How are steel box girders shipped?
In segments sized for standard containers or flat racks, with internal welding and coating completed in the shop and splice plates fitted for site bolting or welding as designed. Girders that exceed out-of-gauge limits are spliced at a low-stress location agreed with your engineer.
Do you fabricate to EN 1993-2 or AASHTO for bridge work?
Either, whichever the project specifies. The difference matters most in fatigue detail classification and weld acceptance criteria, so we ask which code governs before quoting rather than after.
Which design code do you fabricate to?
Whichever your design specifies. We work to AISC 360 or Eurocode 3 (EN 1993) for design intent, and execute to EN 1090-2 EXC2 under certificate 2787-CPR-01627. State the code in your enquiry and the quotation is issued against it.
Can you issue calculations our building authority will accept?
Yes. We provide English structural calculation reports with load combinations and 3D models. Where local regulations require a licensed local engineer to stamp the drawings, we supply the calculation package for their review.
What is a realistic lead time?
For a typical single-building scope the standard cycle is 40 to 50 days: 1–2 weeks from contract to 3D models and shop drawings for your approval, then 4–5 weeks for procurement, CNC fabrication, welding, coating and loading. Drawing approval is the part you control.
Do you supply the enclosure as well as the frame?
Yes. Roof and wall cladding, insulation, waterproofing, doors, windows, ventilation and drainage are quoted as one package — see Enclosure & Cladding Systems . Single-source supply removes the interface risk between frame and envelope.
How do we verify your certificates?
Ask us for the certificate together with its Document of validity — they are issued as an inseparable pair. We send both with the welding annex on request. Details are published on our certificates page .
Send Us Your Drawings or BOQ
Tell us the footprint, span, crane capacity and local loads — our engineering team reviews every request and replies with a preliminary assessment.
- Reviewed by our engineering team
- AISC certified · CE marked EN 1090-2 (EXC2)
- Mutual NDA available on request
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