Factory Welded Box Arch Girder for Urban River Crossing Steel Arch Bridge

• Customization: Available
• After-sales Service: 24/7 Online Technical Support
• Warranty: 1 Year
• Model NO.: Steel Arched Bridge
• Fabrication Mode: Complete Factory Full Automatic Welding
• Core Section: Closed Box Arch Load-Bearing Girder
• Main Application: Urban River Crossing Arch Bridge Projects
• Weld Inspection: Full Ut & Mt NDT for All Critical Seams
• Load Design: Fits Multi-Lane City Traffic Vehicle Load
• Anti-Corrosion: Multi-Layer Composite Paint Coating
• Construction Advantage: Less on-Site Welding & Fast Assembly
• Standard Compliance: Aashto & Aws D1.5 International Codes
• Production Equipment: CNC Cutting & Submerged Arc Welding Line
• Transport Package: Seaworthy Packing
• Specification: High strength structural steel
• Trademark: FAMOUS
• Origin: China
• HS Code: 730890000
• Package Size: 1000.00cm * 200.00cm * 100.00cm
• Package Gross Weight: 50000.000kg
• Lead Time: 25 days (1 - 20 Tons) ; To be negotiated ( > 20 Tons)

Product Description

The AWS D1.5 Fatigue Resistant Steel Arch Bridge Main Bearing Girder is a high-performance structural component engineered for medium-to-long-span highway and railway bridge applications. Fabricated in strict compliance with the AASHTO/AWS D1.5 Bridge Welding Code, this main bearing girder delivers exceptional fatigue resistance, torsional rigidity, and load-bearing capacity essential for modern infrastructure projects.

Design Standards & Compliance

The girder is manufactured in full accordance with the AASHTO/AWS D1.5M/D1.5 Bridge Welding Code (2025 edition), jointly issued by the American Welding Society (AWS) and the American Association of State Highway and Transportation Officials (AASHTO). This code governs welding requirements for carbon and low-alloy constructional steels used in welded bridges. AWS D1.5 imposes materially more demanding requirements than AWS D1.1 (general structural steel) due to bridge cyclic loading, fatigue life requirements, and safety-criticality. All components are designed to AASHTO LRFD Bridge Design Specifications.

Material Specifications

Base materials follow AASHTO M270 (equivalent to ASTM A709) series structural steel grades, including Grade 345 (A709 Gr50), HPS485W high-performance weathering steel, and Grade 690 high-strength low-alloy steel, all within D1.5 applicable scope (yield strength ≤690 MPa). Steel grades feature optimized toughness with Charpy V-notch impact values meeting requirements for the specified temperature zone and load category. Material selection ensures compatibility with welding processes and structural performance requirements.

Structural Configuration

The main bearing girder features a closed-box cross-section design that delivers outstanding torsional rigidity and lateral load distribution capacity, effectively resisting eccentric live loads from highway trucks and high-speed train dynamic impacts. Core welded components include top deck plate, vertical web plates, bottom tension flange plate, longitudinal stiffeners, and transverse intermediate diaphragms. This configuration reduces overall steel consumption compared to traditional I-shaped plate girders under identical span and load design parameters.

Fatigue-Resistant Design

The girder is specifically engineered to withstand millions of load cycles over its service life. Fatigue design follows AASHTO LRFD fatigue provisions, with details grouped into Categories A through E' based on stress concentration severity and expected fatigue life. All fatigue-susceptible details are designed to prevent distortion-induced fatigue cracks. The design incorporates proper edge preparations, joint configurations, and groove angles to achieve sound welds. Optimized girder geometry reduces the risk of fatigue damage over the design service life.

Welding & Fabrication

All welding operations are performed under qualified Welding Procedure Specifications (WPS) with Procedure Qualification Records (PQR) documented per AWS D1.5 requirements. Key welding processes include Submerged Arc Welding (SAW), Flux-Cored Arc Welding (FCAW), Gas Metal Arc Welding (GMAW), and Shielded Metal Arc Welding (SMAW). Controlled heat input prevents distortion and metallurgical defects. Specific preheat and interpass temperatures are maintained to prevent cracking, especially in thick or high-strength steel sections. Full penetration groove welds and fillet welded stiffener systems form the closed hollow cross-sections.

Quality Control & Inspection

Comprehensive quality assurance is implemented throughout all fabrication stages. Visual Testing (VT) serves as the mandatory first-level examination method for all bridge welds, establishing the foundation for quality assurance programs. Nondestructive testing includes 100% Ultrasonic Testing (UT) on tension splice welds, Radiographic Testing (RT) or UT on critical welds, and Magnetic Particle Testing (MT) on additional welds. Visual examination identifies all surface discontinuities that might serve as fatigue crack initiation sites under repeated stress cycles. Fracture Critical Members (FCM) require enhanced visual examination with more restrictive acceptance criteria.

Fracture Control Plan

For nonredundant structures, AWS D1.5 Clause 12 establishes Fracture Control Plan provisions for fracture-critical members. These provisions impose stricter fabrication and shop-inspection requirements to control weld flaws and other crack-like defects. Members subject to tensile stress under live load conditions are classified and managed according to FCM requirements.

Surface Protection & Corrosion Resistance
The girder receives high-quality anti-corrosion treatment to ensure excellent rust and oxidation resistance. Surface protection options include epoxy paint systems (80μm–120μm thickness) or hot-dip galvanizing (≥85μm thickness). Coating systems are compatible with environmental exposure conditions including temperature extremes, moisture, deicing chemicals, and atmospheric contaminants.

Specification

Item	Detailed Description
Material	AASHTO M270 / ASTM A709 Grade 50, HPS 50W, HPS 70W, or Grade 690 high-strength low-alloy steel (yield strength ≤690 MPa)
Cross-Section	Box girder or I-girder configuration; closed-box design with top deck plate, vertical web plates, bottom flange plate, longitudinal stiffeners, and transverse diaphragms
Plate Thickness	Main plates: 12mm–32mm; secondary stiffener and diaphragm plates: 10mm–20mm
Fabrication Length	Shop prefabricated segments: 10–30 meters; field splice welded to full-span continuous girders
Welding Standards	AWS D1.5 qualified WPS/PQR; full penetration groove welds and fillet welded stiffener systems
NDT Requirements	100% UT on tension splice welds; RT or UT on critical welds; MT on additional welds; VT on all welds

Packing & Delivery

Girders are packaged using seaworthy fumigated packing, suitable for container or bulk vessel transportation. Each component is properly secured, braced, and protected against corrosion, moisture, and physical damage during transit. Packaging details are customized based on shipping method and destination requirements. All packages are clearly labeled with product identification, handling instructions, and project reference numbers. Loading and securing plans are provided to ensure safe transportation.

After Sales Service

Comprehensive after-sales support includes 24/7 technical assistance, installation guidance, and on-site support as required. Our team of experienced engineers provides welding procedure consultation, quality documentation review, and technical troubleshooting throughout the project lifecycle. We offer warranty coverage on fabrication quality and workmanship. Spare parts and replacement components are available upon request. Continuous technical support ensures successful project execution from delivery through final installation and commissioning.

Company Profile

We are a leading manufacturer of steel bridge components with extensive experience in fabricating AWS D1.5 compliant structures for highway and railway bridge projects worldwide. Our facility is equipped with advanced CNC cutting, automated welding, and precision fabrication equipment. We hold ISO 3834 and other relevant certifications, ensuring adherence to international quality standards. With a strong commitment to quality, innovation, and customer satisfaction, we have successfully delivered numerous bridge girder projects across North America and global markets. Our engineering team provides custom design services, detailed shop drawings, and full documentation packages to meet diverse project requirements.