What are the scenarios for steel bridges?

2025-03-26 16:24:19

By virtue of its unique material properties and construction advantages, Steel Structure bridge shows excellent adaptability in many complex engineering scenarios. The following are the typical applicable scenarios and core technical characteristics:

I. Large-span bridges across water

Reason for application:

The tensile strength of steel reaches 345-960MPa, and the span breakthrough ability is far more than that of concrete structure, which can support the demand of kilometer-level span.

Adopting box section design, the torsional stiffness is improved by 5-8 times, which can effectively cope with strong wind (such as 60m/s typhoon) and water current impact.

The orthotropic anisotropic steel bridge panel system reduces self-weight by 30%, and the weight per unit length of a cross-sea bridge with a main span of over 1,000 meters is only 26 tons/m.

Technical Highlights:

Double-compartment trapezoidal steel box girder design, combined with aerodynamic profile optimization (e.g., deflector plate), the critical wind speed of flutter is increased to 79m/s.

Welding robot realizes the qualification rate of butt weld seam of 20mm thick plate＞99.5%, which guarantees the precision of main girder of kilometer level.

Second, urban three-dimensional transportation node

Applicable reasons:

Factory prefabrication rate exceeds 90%, modularized steel box girder supports rapid lifting at night (e.g. single-span 75m completed in 8 hours), reducing traffic disruption.

The minimum turning radius can be compressed to 30 meters, adapting to complex interchanges (such as 5-level interchange hub 15 ramp space crossing).

Technical Highlights:

Three-dimensional laser scanning pre-assembly technology, 30-meter span steel girder installation error ±1.5mm, to ensure smooth viaduct line.

The steel-hybrid combination structure reduces the beam height by 30%, releasing the under-bridge clearance of 4.5 meters for a city viaduct, and enhancing the road capacity.

III. Complex geology and seismic zone

Applicable reasons:

Light self-weight (0.8 tons/m3), reduce foundation load by 40%-60% compared with concrete structure, applicable to soft foundation and landslide zone.

Ductility (fracture elongation ≥ 20%) and flexible design can absorb seismic energy, a level 8 seismic zone bridge allows displacement of 1.2 meters.

Technical highlights:

Steel pipe concrete combined pier + steel box girder system, crossing the fracture zone bridge seismic grade up to IX degree.

Modular component helicopter lifting technology, to realize the construction of mountain canyon without stent.

Fourth, emergency and rapid construction scenarios

Applicable reasons:

Completion of standard span bridge erection (prefabricated + bolted connection) in 72 hours, and restoration of traffic in 7 days for a post-disaster emergency project.

The removable and replaceable design supports rapid maintenance, and the guardrail system replacement takes only 8 hours.

Technical Highlights:

Military-grade modular steel bridge with a single span of up to 51 meters, carrying 60 tons of heavy vehicles, adapting to war preparation needs.

Intelligent bolt pre-tensioning system, single node installation efficiency increased by 3 times.

V. Ecologically Sensitive Areas

Applicable reasons:

Construction waste is reduced by 80%, material recycling rate >95%, and carbon emission is 60% of that of concrete bridges.

Maintenance-free anti-corrosion system (e.g. hot-aluminum-zinc plating) protection cycle of 120 years, an ecological protection zone bridge to achieve zero-pollution construction.

Technical Highlights:

Self-cleaning coating technology inhibits the adhesion of marine organisms and reduces maintenance frequency.

Carbon dioxide protection welding process reduces welding fume by 90%, adapting to the environmental requirements of water sources.

Sixth, special function bridge

Applicable reasons:

Steel plasticity to support complex mechanical movements, an open bridge steel box girder 4 minutes to complete 86 ° rotation.

3D printing technology to achieve shaped surfaces, a landscape bridge surface accuracy ± 1.5mm, modeling freedom to enhance 5 times.

Technical highlights:

Modular design of pontoon unit, with a carrying capacity of 500 tons, adapting to water level fluctuation of 10 meters.

Weather-resistant steel combined with intelligent dehumidification system reduces the corrosion rate of coastal bridges to 0.01mm/year.