Bridge-Inventory Ready Plate Girder with QR Traceability to Eurocode, AWS D1.5 & AS 5100

A steel plate girder bridge is a type of I-shaped section girder bridge formed by connecting the top and bottom flange plates and the web plate with fillet welds. Its core principle is to concentrate the steel material in the flanges, where the bending moment is greatest, and in the webs near the supports, where the shear force is greatest. Unlike the closed section of a steel box girder, the open I-shaped section is simple to manufacture, easy to inspect, and naturally forms a drainage slope. The products include simply supported, continuous, and continuous rigid frame systems, with spans ranging from 15 to 60 meters, and are mainly used for highway overpass bridges, railway grade separations, and rapid replacement of old bridges.

1.Scenario Category

2.Product Highlights

l Web Plate with Oval Hole for Weight Reduction: An oval hole with a long axis of 500mm is opened in the mid-span section of the web plate, reducing steel usage by 8–12%, with annular stiffeners set around the hole edges.

l Variable Thickness Flange Plate Splicing: The splice weld is away from high-stress areas. When the plate thickness difference on both sides is ≤4mm, a sloped transition is used, with a stress concentration factor Kt < 1.3.

l Embedded Shear Connectors: Slot steel is embedded in the precast concrete slab, and weld studs are embedded into the slots on site and grouted with mortar, eliminating on-site welding operations.

l Self-Cleaning Dust-Resistant Top Plate: The upper surface of the flange is inclined ≥2%, combined with narrow joint gaps, to prevent long-term accumulation and corrosion from moisture and dust.

l Sacrificial Anode Cathodic Protection: Zinc alloy anode blocks are installed near the bearing pads to protect the lower edge of the web and the bottom surface of the flange.

l Built-in Dampers to Reduce Vibration: Steel boxes are welded on the inner side of the web plate and filled with granular damping material, increasing live load vibration attenuation by 60%.

3.Product Materials

The core load-bearing components of our steel plate girder bridge are all made of high-performance special steel plates for bridges that strictly meet the world's mainstream bridge standards, and the materials are precisely selected according to the stress characteristics of the flange and web of the plate girder. The core material system is as follows:

ü Special steel plate for low alloy high strength bridge: Adopting mainstream special steel plates for bridges such as A36, A572 Grade 50 and Q355B, with yield strength ≥ 345MPa, excellent bending resistance, compression resistance, welding performance and cold bending performance, it is the core main material for the flange and web of the plate girder, which can perfectly adapt to the bending and shear stress requirements of the beam-type structure.

ü High weathering atmospheric corrosion resistant steel plate: Adopting weathering steel plates such as Corten A and Q355NH, a stable and dense passivated rust layer is formed on the surface through alloying design, realizing long-term coating-free anti-corrosion, which is especially suitable for strong corrosion environments such as coastal, high humidity and industrial pollution, and greatly reduces the later anti-corrosion maintenance cost of the plate girder.

ü Stainless steel composite anti-corrosion plate: For extreme environments with high salt spray and strong corrosion, 304/316 stainless steel and carbon steel composite plates are used, which take into account the high strength of carbon steel and the excellent anti-corrosion performance of stainless steel, which can realize anti-corrosion maintenance-free for the whole life cycle of the plate girder and greatly improve the service life of the structure.

ü High performance welding and fastening materials: All plate girder welding adopts low hydrogen high strength welding wire and electrode that meet AWS and EN standards to ensure that the mechanical properties of the welded joint are completely matched with the base metal; component splicing adopts 8.8/10.9 grade high strength bolts that meet ASTM A325 and EN 14399 standards to ensure the rigid connection and uniform stress of the splicing joints.

4.Design Features

Ø Hybrid steel mix reduces costs: The flanges in the negative bending moment region at the supports use S460 high-strength steel, while the flanges in the positive bending moment region at mid-span use S355, saving 8–12% in costs.

Ø High web slenderness ratio regional control: Stiffeners are densified in the area near the supports (1/4 span, a/h ≤ 1.0); in the mid-span area, they can be omitted or spaced widely.

Ø Partial shear connection design: Composite beam shear connection degree η = 0.5–0.7, allowing slight slip at the steel-concrete interface, reducing the number of weld studs by 30%.

Ø Asymmetric flange resists bidirectional bending: In continuous beams at mid-supports, the lower flange area is larger than the upper flange to handle reverse stresses in the negative moment region.

Ø Precise calculation of lateral distribution coefficient: Multiple I-girders connected into an integral unit by transverse diaphragms distribute lane loads according to the eccentric compression method or the grillage method.

Ø Installation verification without temporary supports: During erection, steel plate beams must independently bear their self-weight and wet concrete loads, with a stability coefficient ≥ 1.5.

5.Core Advantages

⭐Maximized factory flexibility: Flanges and webs can be purchased in any length without rolling length restrictions; on-site splicing locations can be flexibly adjusted according to lifting capacity.

⭐Thinnest web application: High slenderness ratio up to 250, with only a 10–15% reduction in shear capacity after applying the tension field effect, minimizing steel usage.

⭐Minimal on-site operations: Prefabricated concrete slabs of composite beams are produced simultaneously with the steel beams, requiring only grouting and beam placement on-site.

⭐Optimal fatigue detail accessibility: All fillet and butt welds are completed in the factory environment and are fully capable of magnetic particle or ultrasonic testing.

⭐Most economical maintenance solution: Local corrosion of webs and flanges can be reinforced by steel plate bonding without scrapping the entire beam, with repair costs only 30% of a new beam.

⭐Fastest lane recovery: Bridges using prefabricated slab composite beams allow single-span replacement within a 48-hour weekend window, reopening traffic before Monday morning peak.

6.Global Standard

7.Choose Us  

Choosing our steel plate girder bridges means you are choosing a path that implements the effects of web tension fields and the economic efficiency of hybrid steel arrangements in every I-beam. We do not just deliver rolled profiles—we deliver stiffener layouts optimized for high-thickness ratios in specific areas, weld reduction schemes calculated with partial shear connections, and precise segment designs that allow on-site splicing positions to avoid bending moment peak zones.