Large Span AASHTO LRFD Steel Arch Bridge for Urban Transport Engineering Projects

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  Design Method: Load and Resistance Factor Design (LRFD); all strength, service, fatigue and extreme limit states fully verified.
• Design Load: HL-93 (design truck + lane load) – mandatory baseline load standard of AASHTO.
• Steel Design: Designed in accordance with AASHTO LRFD Section 6, covering flexure, shear, combined loading, fatigue and fracture control.
• Seismic Design: Compliant with AASHTO LRFD seismic provisions, suitable for steel arch structures.
• Design Life: 75 – 100+ years under regular maintenance.
   

AWS D1.5M Welding Certification

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  Code Standard: AASHTO/AWS D1.5M Bridge Welding Code, more stringent than general AWS D1.1.
• Fracture-Critical Members: 100% ultrasonic testing (UT) implemented for all primary load-carrying welds.
• Production Personnel: All welders hold AWS certification; Certified Welding Inspectors (CWIs) supervise the whole fabrication process.
• NDT Inspection: UT for full-penetration welds; supplementary MT/PT inspection arranged where required.
   

Specifications

Closed-Box Arch Advantages

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  Superior torsional rigidity – perfectly adapted for skewed crossings and eccentric loading scenarios
• Excellent buckling resistance – core guarantee for long-span unbraced arch structures
• Favorable strength-to-weight ratio – realizes longer clear spans with lighter structural sections
• Built-in internal stiffeners – inhibits local buckling and optimizes load distribution
• Improved corrosion resistance – enclosed inner surfaces lower long-term maintenance workload
• Attractive visual effect – sleek modern profile for landmark urban signature bridges
   

Prefabrication – Built for Urban Environments

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  100% shop fabricated – all components manufactured under controlled factory conditions.
• Full factory preassembly – complete dimensional matching verification before shipment to avoid on-site rework.
• Modular segmented design – convenient for highway or barge transportation within urban zones.
• Bolted field joints – eliminates field welding, avoids construction delays caused by poor weather and cuts site manpower demand.
• Short erection cycle – finished within days or weeks instead of months, greatly easing traffic pressure in crowded urban areas.
   

Quality Assurance

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  Raw Material: Certified ASTM A709 steel with complete Mill Test Reports (MTRs).
• Welding Works: Completed by AWS-certified welders; all WPS/PQR qualified per AWS D1.5M.
• NDT Control: 100% UT inspection for primary load-carrying welds; MT/PT carried out as needed.
• Preassembly: Full one-side preassembly to validate all connection interfaces.
• Surface Treatment: Industrial blast cleaning followed by epoxy paint or hot-dip galvanizing coating.
• Third-Party Audit: Supports inspection by SGS, Bureau Veritas or client-appointed organizations.
• Technical Documents: Full document package including design calculations, MTRs, WPS/PQR, NDT reports and as-built drawings.
   

Conclusion – Large Span, Urban Ready, AASHTO Certified

• • Full AASHTO LRFD compliance, accepted by authorities across North America
• • Outstanding spanning capacity, requiring fewer intermediate supports
• • Rapid construction via prefabricated bolt-connected modules
• • Less disruption to public traffic, ideal for densely built urban regions
• • Reliable long-term performance with a 75 – 100+ year design lifespan
• • Comprehensive compliance documentation to accelerate project approval