1、 Core advantages of rigid Steel Structure bridges

Ultra high stiffness and bearing capacity

Adopting designs such as box section and I-beam combination, the bending stiffness is increased by 50% compared to truss structures, making it suitable for large-span heavy-duty bridges;

Typical parameters: steel box girder section height of 2-6m, top and bottom plate thickness of 20-50mm (Q345qD material), single span bearing capacity ≥ 50000kN/m.

Excellent seismic and wind resistance performance

Node rigid connection: fully welded or high-strength bolt connection, with a shear bearing capacity of ≥ 5000kN (GB 50017 standard);

Power optimization design: first-order natural frequency ≥ 1.2Hz, suppressing vortex induced vibration (verified by wind tunnel tests).

Rapid assembly construction

Factory prefabrication rate ≥ 95%, on-site modular assembly, shortened construction period by 60% (such as a 300m span bridge completed in 12 months);

Maximum lifting unit: Steel box girder segment length of 30m, weight of 800 tons (equipped with a thousand ton floating crane).

Whole life cycle economy

70% reduction in maintenance costs: hot-dip galvanizing+fluorocarbon coating (50 year maintenance free);

The recyclability rate is ≥ 98%, and the carbon emissions are reduced by 40% compared to concrete bridges.

2、 Core product series and technical parameters

3、 Key Design and Manufacturing Technologies

structure optimization

Finite Element Analysis (FEA):

Perform static and dynamic analysis using ANSYS/MIDAS to ensure uniform stress distribution (peak stress ≤ 0.8 σ y);

Fatigue verification: Detail category ≥ 100 under 2 million cycles of load (EN 1993-1-9 standard).

Anti overturning design:

Lateral stability coefficient ≥ 1.5 (JTG D60-2015 standard);

The deviation of the support reaction force is ≤ 5%.

Precision manufacturing process

Numerical Control Cutting and Groove Processing:

Laser cutting accuracy ± 0.5mm, groove angle error ≤ 0.5 °;

U-rib robot welding: weld penetration depth ≥ 80%, UT inspection pass rate ≥ 99.5%.

Box girder assembly technology:

Anti deformation pre bending control, with a straightness of ≤ 3mm/10m after assembly;

Multi partition synchronous assembly, with a spacing error of ≤± 2mm.

Long term anti-corrosion system

Arc spraying aluminum+sealing paint:

Aluminum layer thickness of 200 μ m, sealing paint thickness of 80 μ m, salt spray resistance of ≥ 20000 hours;

Stainless steel composite plate:

Base Q345qD+cladding 304 stainless steel (3mm), maintenance free throughout its entire lifespan.

4、Intelligent operation and monitoring

Structural Health Monitoring (SHM)

Sensor network:

Fiber Bragg Grating Strain Gauge (Accuracy ± 1 μ ε);

GPS displacement monitoring system (accuracy ± 2mm).

Data analysis platform:

A BIM based digital twin system that provides real-time warning of abnormal deformation and stress concentration.

Robot inspection

Magnetic adsorption crawling robot:

Equipped with high-definition camera and infrared thermal imager to detect coating peeling and internal defects;

The accuracy of AI crack recognition is ≥ 98%.

Preventive maintenance

Bolt health monitoring:

Intelligent gasket real-time transmission of pre tightening force data, warning of loosening risks;

Coating life prediction:

The machine learning model based on environmental corrosion data has a residual life estimation error of ≤ 8%.

5、Full cycle service support