Bridging Distances with Precision Engineering
Steel bridges offer unparalleled advantages over traditional concrete structures, specifically their phenomenal strength-to-weight ratio. This makes them the ultimate solution for large-span river crossings, elevated highways, and urban pedestrian overpasses.
From heavy-duty box girders supporting constant vehicular traffic to modular Bailey bridges designed for rapid emergency deployment, Xin Qiao Steel Structure utilizes high-tensile structural steel combined with deep anti-corrosion galvanization to ensure 50+ years of maintenance-free service life.
- Exceptional Spanning Capability
- Rapid Modular Erection
- High Seismic & Wind Resistance
- Marine-Grade Anti-Corrosion
Bridge Typology & Key Components
Steel Truss Bridges
The most efficient design for long spans. Built from an interconnected network of triangles using high-grade tubular or H-section steel to distribute heavy dynamic loads evenly.
Bailey Bridges
Modular, pre-fabricated systems designed for rapid assembly. Perfect for emergency relief, temporary detours, or remote areas lacking heavy lifting equipment.
Pedestrian Overpasses
Sleek steel box girders or arched frames providing safe, highly aesthetic urban crossing solutions, often integrated with glass canopies and lighting.
Box Girder Bridges
Enclosed steel tubes offering immense torsional stiffness. Ideal for curved highway overpasses and light rail transit lines requiring high aesthetic appeal.
Bridge Engineering Specifications
Manufactured in strict adherence to AASHTO and international bridge codes, ensuring absolute safety for public infrastructure.
| Bridge Span Capacity | 15m to 150m+ (depending on structural type: Bailey, Truss, or Arch) |
|---|---|
| Main Steel Material | High-tensile Q355B / Q420 / ASTM A572 Gr.50 or higher grade bridge structural steel |
| Decking System | Orthotropic steel deck / Concrete composite deck / Anti-skid checkered steel plate |
| Connection Methods | Friction-grip high-strength bolts (Grade 10.9) and full-penetration factory submerged arc welding |
| Surface Anti-Corrosion | Hot-Dip Galvanized (HDG) up to 85μm-100μm / Multi-layer marine grade epoxy & polyurethane coating systems |
| Design Standards | AASHTO, Eurocode, or GB (depending on project location requirements) |
| Fatigue Resistance | Engineered to withstand millions of dynamic stress cycles from heavy vehicle/train loads |
Advanced Bridge Fabrication
Bridges demand zero margin for error. Our engineering team utilizes advanced finite element analysis (FEA) and Midas Civil software to simulate dynamic traffic loads, seismic shocks, and wind resonance before manufacturing begins.
Pre-Assembly Verification
For complex truss bridges, we conduct a full-scale pre-assembly test in our factory lot to verify perfect alignment of all bolt holes before shipping.
Flawless Automated Welding
Critical stress points are welded using multi-pass submerged arc welding, ensuring 100% penetration and zero internal defects.
Extreme Environment Coating
For river or coastal bridges, we utilize deep hot-dip galvanization combined with heavy marine-grade epoxy paints to halt corrosion entirely.
Comprehensive 30-Step Quality Control
Zero compromises on safety. Before shipping, your bridge components must pass our strict factory inspection protocol compliant with GB 50205-2020 and AWS D1.5 bridge welding standards.
| Category | No. | Inspection Item | Acceptance Criteria & Tolerance | Method / Tools |
|---|---|---|---|---|
| I. Raw Material Incoming | 1 | Material Certification | Original Material Test Certificates (MTC) required; Grade, Size, and Heat No. must match the physical material. | Document Review |
| 2 | Stamps & Markings | Steel surface must have clear manufacturer stamps or batch IDs. Tracking numbers must be legible. | Visual Check | |
| II. Thickness Acceptance | 3 | Under-Tolerance Control | Under-tolerance must be within limits. For Export: Recommended actual thickness ≥ Nominal -0.3mm. | Micrometer / UT Gauge |
| 4 | Surface Defects | No bubbles, scabs, cracks, inclusions, or pressed-in iron oxide scale allowed. | Visual Check | |
| III. Cutting & Nesting | 5 | Part Dimensions | Length & Width tolerance: ±2.0 mm. | Steel Tape |
| 6 | Cut Perpendicularity | ≤ 10% of thickness, and max ≤ 2.0 mm. | Square / Feeler Gauge | |
| 7 | Cut Surface Roughness | Machine Cut ≤ 0.2 mm; Manual Cut ≤ 0.3 mm. | Roughness Template | |
| 8 | Notches / Edge Defects | Depth ≤ 1.0 mm; deeper defects must be ground smooth or repaired. No sharp notches allowed. | Depth Gauge | |
| IV. Assembly / Fitting | 9 | Jig & Leveling | Platform flatness deviation ≤ 3.0 mm; tack welds must be sound and free of cracks. | Level / Visual |
| 10 | Section Size (H/B) | Height & Width tolerance: ±2.0 mm. | Steel Tape | |
| 11 | Web Center Offset | Web center to Flange center offset ≤ 2.0 mm. | Steel Ruler | |
| 12 | Flange Squareness | Deviation b/100 and ≤ 2.0 mm. | Square / Feeler Gauge | |
| 13 | Overall Length | Total component length tolerance: ±3.0 mm. | Steel Tape / Laser | |
| 14 | Assembly Gap | Joint gap: 1.0 ~ 3.0 mm (depending on WPS). | Feeler Gauge | |
| V. Welding Execution | 15 | Pre-weld Cleaning | No rust, oil, or moisture within 20mm of the groove/edge. | Visual Check |
| 16 | Weld Appearance | No cracks, weld bumps, burn-through, or craters; Reinforcement: 0 ~ 3 mm. | Weld Gauge | |
| 17 | Weld Leg Size | Meet design requirements; Tolerance: 0 ~ +3.0 mm. | Weld Gauge | |
| 18 | Internal Defects | No surface porosity/slag in Class I welds; Undercut strictly controlled. | Magnifier / Visual | |
| 19 | NDT (UT/RT) | 100% UT/RT on all main bridge girders and critical tension joints. | NDT Report | |
| VI. Shot Blasting | 20 | Blast Grade | Must reach Sa 2.5 Grade (Near-white metal, no visible scale/rust). | Visual Comparison |
| 21 | Surface Roughness | Maintain 40 ~ 75 μm (or per paint datasheet). | Roughness Gauge | |
| 22 | Cleanliness | Surface must be blown clean; no dust, oil, or residual steel grit. | White Cloth Test | |
| VII. Coating & Painting | 23 | Dry Film Thickness | 80-20 Rule: 80% points meet spec; 20% points not less than 80% of spec. | DFT Meter |
| 24 | Coating Integrity | No damage, no missed spots, no sags, and strictly NO RUST SPOTS. | Visual (100%) | |
| 25 | Adhesion | Cross-cut test must achieve Grade 0 ~ 1. | Cross-cut Kit | |
| VIII. Final Audit & Loading | 26 | Global Geometry | Strict adherence to bridge camber requirements. | Plumb Line / Tape |
| 27 | Pallet/Crate Quality | Pallets must be robust; load-bearing capacity must prevent deformation. | Load Inspection | |
| 28 | Container Fit | Overall package width fits container interior or flat-rack specifications. | Steel Tape | |
| 29 | Categorized Stacking | Sorted stacking; use timber or rubber pads between items to prevent paint damage. | Visual Check | |
| 30 | Bracing & Lashing | Items secured to pallets, and pallets secured to container via steel straps. | Tightness Check |
Steel Bracket Packaging System
To guarantee that your massive bridge girders and truss components arrive in pristine condition, we abandon traditional loose loading. Instead, we utilize a proprietary Steel Bracket Unitized Packaging System.
Massive steel box girders, Bailey bridge panels, and arch components are meticulously categorized, padded with protective rubber, and strapped onto heavy-duty steel skids. This not only prevents paint friction and collision damage during ocean transit but also allows for rapid, one-lift crane unloading at your construction site.
- Zero Paint Damage Guarantee
- Maximized Container Space Utilization
- Fast & Easy On-Site Unloading
Related Bridge Projects
Explore how our steel bridges are conquering challenging terrains and transforming urban connectivity around the world.
50-Meter Span Steel Truss Bridge
Clear Span: 50 Meters
Weight: 400 Tons
Galvanized Steel Bailey Bridge
Type: Bailey / Truss Bridge
Advantage: Fast Modular Erection
Steel Pedestrian Overpass
Type: Pedestrian Bridge
Treatment: Hot-Dip Galvanized
Frequently Asked Questions
Key structural systems, international design standards, cost metrics, and erection methods for prefabricated steel structure bridges.
1. What types of steel structure bridges does XinQiao Steel manufacture?
XinQiao Steel specializes in the custom engineering, precision fabrication, and global export of three primary structural steel bridge types:
- Prefabricated Steel Truss Bridges: Engineered with Warren, Pratt, or K-truss configurations spanning 30m to 120m+. Ideal for wide river crossings, railway spans, and heavy vehicular highways (see our featured 50-Meter Span Steel Truss Bridge in Argentina).
- Modular Bailey Bridges (Compact 100 / Compact 200): Standardized, pin-connected panel systems designed for rapid deployment, emergency flood relief, military logistics, and remote access (see our Fast Erection Galvanized Steel Bailey Bridge in Malaysia).
- Steel Box Girder & Pedestrian Overpass Bridges: High-rigidity closed hollow section girders offering immense torsional stiffness for urban flyovers, curved interchange ramps, and modern aesthetic footbridges (see our Steel Structure Pedestrian Overpass in Yunfu).
2. How do I choose between a Steel Truss Bridge, a Box Girder Bridge, and a Bailey Bridge?
The optimal bridge system depends on span length, site logistics, erection equipment, and functional requirements:
- Choose a Bailey Bridge if: You require fast installation (assembled in days with minimal crew), have remote or inaccessible terrain, lack heavy crane equipment, or require a temporary detour bridge that can be easily dismantled and re-erected elsewhere.
- Choose a Steel Truss Bridge if: You are spanning a medium-to-long clear opening (40m–100m+) where minimizing crosswind resistance and reducing dead weight are critical. Truss structures provide the highest strength-to-weight ratio for heavy traffic loads.
- Choose a Steel Box Girder Bridge if: You are constructing modern highway viaducts, curved roadway ramps, or urban overpasses demanding maximum torsional rigidity, slender profiles, and sleek architectural appearance.
3. What is the average fabrication cost and supply pricing for a prefabricated steel bridge?
Bridge steel fabrication costs are generally calculated per metric ton or bridge deck surface area (FOB factory supply):
- Modular Bailey Bridge Panels: Typically $1,300 – $1,800 USD per metric ton (fully hot-dip galvanized, including standard chord panels, transoms, sway braces, and connection pins).
- Heavy Structural Steel Truss Bridges: Typically $1,400 – $2,100 USD per metric ton (calculated with high-strength Q355B/Q355D steel plates, Gusset plates, and pre-welded truss chords).
- Welded Steel Box Girders: Typically $1,600 – $2,400+ USD per metric ton (reflecting internal diaphragm fitting, orthotropic steel deck plates, and 100% full-penetration welding inspections).
Note: Pricing varies based on steel grade (e.g., Q355D/E, ASTM A709 Gr. 50), paint coating standards (C4/C5 marine specs), and live load requirements (AASHTO HL-93 or Eurocode LM1). Contact our engineering team for a complimentary, itemized Bill of Quantities (BOQ).
4. Which international design codes and bridge welding standards does XinQiao Steel follow?
Every bridge component fabricated by XinQiao Steel is calculated and detailed in strict compliance with international highway and railway bridge norms:
- Design Codes: AASHTO LRFD Bridge Design Specifications (North America), Eurocode 3 & 4 (EN 1993-2 for Steel Bridges and EN 1994-2 for Composite Bridges), and AS 5100 (Bridge Design, Australasia).
- Welding & Execution: Certified to AWS D1.5 (Bridge Welding Code), AWS D1.1, and EN 1090-2 (Execution Class EXC3 / EXC4) for high-fatigue highway structures.
- Material Standards: Premium impact-tested structural steel matching ASTM A709 Gr. 50/50W, EN 10025 S355JR/J2/NL, and GB/T Q355C/D/E or Q420qD.
5. How does XinQiao Steel ensure zero on-site assembly errors for overseas bridge projects?
To eliminate costly field corrections on overseas job sites, we enforce a comprehensive three-tier fit-up verification protocol:
- 100% Factory Trial Pre-Assembly: Before packaging, primary truss segments, bridge chords, and box girder joints undergo a full 1:1 physical shop pre-assembly to verify camber, hole alignments, and pin tolerances.
- Precision CNC Laser & Multi-Spindle Drilling: All gusset plates, flange splice holes, and diaphragm connections are processed on multi-axis CNC drilling centers with sub-millimeter bolt-hole tolerances.
- Non-Destructive Testing (NDT): 100% Ultrasonic Testing (UT) and Magnetic Particle Inspection (MT) are conducted on all critical tension flanges and full-penetration groove welds, backed by third-party NDT reports.
6. What anti-corrosion coating systems are applied to guarantee a 50- to 100-year bridge lifespan?
Bridges are continuously exposed to humidity, de-icing salts, and coastal airborne chlorides. We supply certified corrosion protection systems tailored to ISO 12944 corrosivity categories (C3 to CX):
- Deep Hot-Dip Galvanization (HDG): Bailey panels, cross-braces, and secondary floor systems are galvanized to ASTM A123 / ISO 1461 with zinc coating thickness of 85µm to 120µm+ (600–850 g/m²) for maintenance-free durability.
- Heavy-Duty Marine Paint Systems: Automated Sa 2.5 blast cleaning, followed by zinc-rich epoxy primer (75–80µm), epoxy micaceous iron oxide (MIO) intermediate coat (100–150µm), and polyurethane or fluorocarbon weather-resistant topcoats (60–80µm).
- Thermal Spray Aluminum/Zinc (TSA/TSZ): Optional metalizing coating for harsh offshore or marine splash-zone applications.
7. How are prefabricated steel bridges packaged, shipped, and erected on-site?
Our logistics and erection engineering are optimized for overseas container shipping and straightforward site installation:
- Containerized Shipping: Components are modularly segmented to fit standard 40ft High Cube (HC) containers or Open Top containers. Heavy box girder segments are transported via breakbulk or flat racks with welded lifting lugs.
- Cantilever Launching (Bailey Bridges): Bailey bridges can be pushed across rivers using a lightweight launching nose, rollers, and winches—requiring no in-stream piers or heavy cranes.
- Crane Hoisting & Strand Jacking: Prefabricated truss and box sections arrive color-coded and stamped with erection markings corresponding directly to our 3D Tekla step-by-step assembly blueprints.