ICF(Insulated Concrete Form) Bracing
Prefabricated Steel Box Girder Bridge | AASHTO, AWS D1.5, EN 1090-2 EXC4 Certified
The Prefabricated Steel Box Girder Bridge is a factory prefabricated modular steel superstructure, designed for fast on-site erection and long-term stable service. The enclosed box section delivers excellent torsional stiffness and uniform load distribution, perfectly suited for curved bridges, skew crossings and construction sites with limited working space.
Designed in accordance with AASHTO LRFD, fabricated following AWS D1.5 welding specifications and certified to the highest EN 1090-2 EXC4 execution class, this bridge system satisfies the strictest international standards for structural safety, durability and quality control.
Design & Engineering Features
Each bridge is tailor-made based on actual site conditions with professional optimized design:
- •AASHTO LRFD 9th Edition Certified Adopts Load and Resistance Factor Design system, covers HL-93 live load, fatigue, fracture limit states and extreme load conditions; curved girders calculate warping torsion and diaphragm force precisely.
- •Adjustable Section Size Fixed or variable beam depth available; span-depth ratio ranges from 1:18 ~ 1:25; bottom flange width optimized for stable hoisting and erection.
- •Dual Deck Options Top flange supports composite concrete deck or orthotropic steel deck freely, flexible to match different project requirements.
- •Superior Seismic & Wind Resistance Closed box structure comes with natural vibration damping, stable mechanical performance under earthquake and wind loads.
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•Flexible Field Connection
Field splices adopt bolted or welded forms, convenient for assembling multi-span continuous bridges and convenient long-distance transportation.
Standard & Code Compliance
| Code / Standard | Application Scope |
|---|---|
| AASHTO LRFD | Bridge overall design: load bearing, usability, fatigue calculation |
| AWS D1.5 | Welding process formulation, welder certification & weld inspection |
| EN 1090-2 EXC4 | CE marking, fabrication tolerance control, steel structure quality management |
| ASTM A709 | Structural steel plate: Grade 36, 50, 50W, HPS 70W |
| ISO 9001:2015 | Whole-process quality management for production & delivery |
Compliance with the above codes enables smooth project approval in North America, Europe and other global regions.
Material Quality & Selection
All steel materials are purchased from certified steel mills, complete with official mill test reports (MTR) for chemical composition and mechanical property verification:
- •Main Structural Steel: ASTM A709 Grade 50W weathering steel / HPS 70W high-performance steel (thickness reduction & weight saving); equivalent European S355J2W, S460M available on request
- •Welding Consumables: Low-hydrogen welding rods & flux-cored wires, matched with base metal strength and toughness
- •High-Strength Fasteners: ASTM A325 / A490 friction-type high-strength bolts for field splicing
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•Anti-Corrosion Coating: Customizable schemes: three-layer paint system, thermal spray metallizing for coastal & severe corrosive environments
Prefabrication & Shop Fabrication
All bridge components are entirely manufactured indoors under ISO quality management system:
- •CNC Precision Cutting: Plasma & oxy-fuel CNC cutting ensures accurate plate size and welding edge processing
- •Automatic SAW Welding: Tandem submerged arc welding for longitudinal flange-web welds, stable penetration and minimal deformation
- •Component Pre-Assembly: Diaphragms, stiffeners and connection plates prefabricated firstly before box girder overall closure
- •Shop Dry Trial Assembly: Segments are fitted together indoors to check splicing accuracy before shipment
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•Anti-Rust Pretreatment: Blasting to Sa 2.5 cleanliness standard, immediate primer coating to avoid surface rust
Inspection & Testing
Strict multi-stage testing runs through the whole production cycle:
- •NDT Non-Destructive Testing: Full visual inspection; 100% MT magnetic particle inspection for fillet welds; UT ultrasonic inspection for full penetration butt welds
- •Toughness Verification: Charpy V-Notch impact test to guarantee anti-fracture performance under low temperature
- •Hardness Test: Avoid hydrogen-induced cracking for high-strength steel
- •Dimensional Calibration: Repeated size check after assembly, welding and painting
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•Third-Party Witness Inspection: SGS, BV, TÜV and other authoritative institutions are acceptable for on-site supervision
Quality Assurance System
| Item | Details |
|---|---|
| Welder Qualification | All welders hold valid AWS D1.5 & EN 1090 certificates |
| Welding Procedure | PQR procedure qualification & WPS issued in accordance with international codes |
| Full Material Traceability | Complete record from steel ingot to finished bridge members |
| Coating Inspection | DFT dry film thickness, adhesion and porosity test per SSPC standards |
| Complete Documentation | MTR certificates, NDT reports, as-built drawings and full QA dossier delivered together |
Conclusion
Prefabricated steel box girder bridges serve as a flexible, code-compliant and economical infrastructure solution with excellent long-span performance. Factory prefabrication drastically shortens site construction period; strict implementation of AASHTO, AWS D1.5, EN 1090-2 EXC4 standards secures long-term safety and service life.
All products are designed and manufactured by Hangzhou FAMOUS Steel Engineering Co., Ltd. (FASECbuildings), a professional steel bridge manufacturer located in China. We supply North America, Europe, Middle East and Southeast Asia markets with mature fabrication capacity, on-time delivery and professional technical after-sales support.
Cooperate with us to finish your bridge project efficiently with guaranteed schedule, quality and budget. Contact us now for technical consultation and personalized quotation.
