Pedestrian Overpass

1. Which scenarios are suitable for steel structure pedestrian bridges and corridors?

1.1 Urban transportation hub (subway entrance, high-speed rail station connection)

• Structural advantages: It uses box-section steel trusses with a single span of up to 30 meters, realizing a column-free passage space, avoiding columns blocking the line of sight, and improving the efficiency of crowd control.
• Construction efficiency: The rate of prefabricated modular components in the factory reaches 90%, and the on-site assembly period is 50% shorter than that of traditional concrete. The main structure of the 200-meter overpass can be completed in only 45 days, reducing the impact on urban traffic.
• Functional design: Equipped with anti-slip and wear-resistant steel pedals (load ≥5kN/㎡), an intelligent lighting system, and barrier-free ramps to meet the passage needs of passengers carrying luggage.
• Design highlights: Streamlined skybridges, such as curved and zigzag shapes, can be designed, matched with glass curtain walls or perforated aluminum plate surfaces, such as the “crystal necklace” shape of the Shanghai Lujiazui Ring Corridor, which has become a city landmark.
• Cost reference: The unit cost is about $600-800 USD/㎡, and the comprehensive cost is 20% lower than the concrete solution.

1.2 Commercial complex corridor (shopping mall, office building, aerial connection)

• Spatial integration: The steel structure corridor designed based on BIM technology can realize the vertical linkage of the upper and lower commercial spaces. The main construction period of the corridor below 6 floors only takes 30 days, and it integrates sunshades, advertising screens, and air-conditioning systems.
• Flexible expansion: Modular interfaces support later expansion. For example, the Shenzhen MixC corridor uses the “dismantle and build” technology to complete the connection of new cross-street corridors during business hours without affecting merchant operations.
• Load-bearing performance: Adopting GB, EN, and AISC design specifications and using Q355B S355JR A572 SM490A high-strength steel, the floor load reaches 3.5kN/m², which can meet the needs of dense crowds and temporary promotional activities.
• Aesthetic design: Special-shaped steel components are cut through CNC to achieve curved and spiral shapes, such as the wavy roof of the “Sky Link” corridor in Chengdu Taikoo Li, which is combined with light-transmitting soft membranes to create a transparent space.
• Cost reference: unit cost is $700-900 USD/㎡, suitable for high-end commercial districts.

1.3 Scenic area/park landscape corridor (ecological trail, viewing bridge)

• Eco-friendly: The steel structure is lightweight (only 1/3 of concrete), which reduces damage to the terrain; it uses hot-dip galvanizing anti-corrosion technology, with a maintenance-free period of 20 years, reducing interference with the natural environment.
• Various shapes: special structures such as suspension bridges and cable-stayed bridges can be designed. For example, the Zhangjiajie Glass Scenic Skybridge uses a steel structure frame + full glass panels to achieve a “floating in the air” viewing effect.
• Safety guarantee: Wind resistance level 10, earthquake resistance level 7, equipped with anti-collision guardrails and emergency evacuation passages, and certified by GB, EN, and AISC design specifications for steel structure design.
• Environmental protection features: Steel is 100% recyclable, construction waste is reduced by 85%, and carbon emissions are 60% lower than concrete, which is in line with the green construction concept of the scenic area.
• Cost reference: unit cost $550-750 USD/㎡, suitable for nature reserves and tourist attractions.

2. Why do global cities prefer steel structure bridges and corridors?

2.1 Rapid construction to reduce urban disturbance

• Factory prefabrication + on-site hoisting mode: The main structure of a 100-meter overpass can be completed in just 30 days, which is 75% shorter than traditional concrete pouring (120 days), avoiding long-term road occupation for construction.
• Nighttime rapid assembly technology: Using modular pre-assembly, key nodes can be hoisted within 8 hours at night, minimizing the impact on daytime traffic.

2.2 Freedom of shape, defining urban aesthetics

• The high plasticity of steel supports complex geometric forms, such as the double helix structure of the “Aerial Silk Road” corridor in Beijing’s Shougang Park, which enables a dialogue between architecture and industrial heritage sites through parametric modeling.
• Diversity of surface materials: It can be matched with perforated aluminum panels, carbon fiber panels, green curtain walls, etc., such as the vertical greening system of Singapore’s “Super Tree” corridor, to achieve the integration of architecture and nature.

2.3 Safe and durable, full-cycle guarantee

• High-strength steel: The main structure adopts Q355B S355JR A572 SM490A high-strength steel with a tensile strength of ≥390MPa, which increases the safety factor by 30% compared with traditional concrete structures.
• Intelligent monitoring system: Integrates strain sensors and displacement meters to monitor bridge vibration and displacement data in real time. For example, the Internet of Things monitoring platform of the Guangzhou Tower Pedestrian Bridge can provide early warning of structural abnormalities.

2.4 Green and sustainable, in line with ESG goals

• Photovoltaic integrated design: Photovoltaic glass (BIPV system) can be laid on the top of the overpass, and the annual power generation can cover 50% of the lighting electricity. For example, the Shanghai Hongqiao Hub Photovoltaic Corridor reduces CO2 emissions by about 20 tons per year.
• Detachable modular structure: The component reuse rate exceeds 80%. When the urban planning is adjusted, the steel structure overpass can be moved to a new location as a whole to reduce demolition waste.

3. Application scenarios and technical solutions

Scene Type	Technical Solution	Core Performance	Cost reference
Main road overpass	Steel truss + glass railing	Single span 25 meters, crowd load 3.5kN/㎡, wind resistance 10	$650-850 USD/㎡
Commercial Sky Corridor	Steel frame + aluminum alloy ceiling	Span 18 meters, sound insulation ≥ 40dB, equipped with an air conditioning system	$750-950 USD/㎡
Scenic viewing suspension bridge	Cable suspension structure + anticorrosive wood panel	Span 80 meters, wind resistance 12, load 2.5kN/㎡	$800-1000 USD/㎡
Campus/Hospital Corridor	Light steel frame + awning	Span 12 meters, construction period 20 days, barrier-free design	$500-700 USD/㎡

4. Steel Structure vs. Traditional Concrete: In-depth Comparison

Core indicators	Steel structure scheme	Traditional concrete solution
Maximum span of a single span	30 meters (without columns)	≤15 meters (pillars required)
100m construction period	30 days to complete the main construction	120 days (including maintenance)
Structural deadweight	300-500kg/㎡	1500-2000kg/㎡
Styling flexibility	Can realize complex shapes such as curved surfaces and cantilevers	Depends on templates, limited form
Carbon emissions	0.8tCO₂/㎡ (60% reduction)	2.0tCO₂/㎡
Renovation cost	Component replacement costs are 50% lower	High cost of demolition and reconstruction

5. Key Components and Technical Standards

Load-bearing system

• Steel box girder: Made of high-strength steel, with a cross-section height of 800-1200mm and a bending stiffness of 1.5×10^6N・m², it can meet the load-bearing requirements of large spans.
• Steel tube truss: triangular grid system, the rods only bear axial force, and the material strength utilization rate reaches 95%, which is suitable for large-span scenes such as observation decks.
• Earthquake-resistant bearing: Equipped with spherical steel bearing or elastic sliding plate bearing, it can withstand horizontal earthquake force of 1.2kN/㎡, and displacement deformation ≤50mm.

Enclosure and decoration system

• Anti-slip pedal: hot-dip galvanized steel grating (toothed surface), friction coefficient ≥ 0.6, safe for travel in rainy and snowy weather.
• Noise barrier: double-layer color steel sandwich panel (filled with 100mm rock wool), sound insulation ≥35dB, suitable for busy traffic sections.
• Smart lighting: LED linear lights are combined with solar photovoltaic panels, with an illumination of ≥300lux and energy consumption reduced by 60% compared to traditional lamps.

6. Frequently Asked Questions

Q1. Is the steel structure pedestrian bridge safe? How is the wind and earthquake resistance?
A: The steel structure pedestrian bridge adopts high-strength steel and scientific structural design, and the safety level reaches level 1. The main structure uses Q355B S355JR A572 SM490A steel (compressive strength 345MPa), the wind resistance level can reach 10-12 (typhoon support is configured in coastal areas), and the seismic fortification intensity is 7-8 degrees, which meets the seismic specifications. For example, the Shenzhen Bay Port steel structure bridge has been optimized through wind tunnel tests and can withstand a level 12 typhoon (wind speed 32.7m/s), and is equipped with a full-process stress monitoring system to ensure structural safety in real time.

Q2. How long is the construction period of the steel structure corridor? Will it affect traffic?
A: The steel structure corridor adopts factory prefabrication + on-site assembly mode, and the construction period is shortened by 50%-70% compared with traditional concrete. Taking a 100-meter corridor as an example, the main structure only takes 25 days to complete, and 90% of the components are processed in the factory. Only hoisting and splicing are required on-site. Night construction or segmented closure can be adopted to minimize the impact on ground traffic. For example, the Beijing World Trade Corridor uses weekend nights to complete hoisting and achieve “zero daytime road closure” construction.

Q3. Is the later maintenance cost of a steel structure overpass high? How to prevent corrosion and rust?
A: The maintenance cost of a steel structure overpass is controllable, and the average annual maintenance cost accounts for about 3%-5% of the initial cost, mainly including anti-corrosion coating renewal (once every 10 years) and structural inspection. The dual anti-corrosion process of hot-dip galvanizing (coating thickness ≥85μm) + fluorocarbon paint is adopted, and the maintenance-free period can reach 20 years; epoxy zinc-rich primer can be added in coastal high salt fog areas, and the maintenance frequency only increases by 20%. Compared with concrete structures, steel structures are more convenient to maintain, local components can be replaced separately, and the full life cycle cost is 15%-20% lower.

Q4. Can the steel structure corridor be designed into an arc or a special shape? How to achieve it?
A: Steel structure corridors can achieve diversified shapes through special-shaped steel components and BIM technology. Use parametric modeling to design curved trusses, use CNC cutting equipment to process rods (accuracy ±1mm), and use three-dimensional coordinate positioning and installation on site. For example, the “Yunqiao” corridor in Chengdu Financial City adopts a hyperbolic steel box beam structure. Through segmented pre-assembly and hydraulic lifting technology, it accurately achieves a 270-degree arc suspension effect, combining mechanical properties with visual impact.

Comparison Dimensions	Traditional construction method	Construction method of steel structure corridor based on BIM and parameterization
Design Phase	Two-dimensional drawing design, difficult to adjust the shape, prone to design omissions	Use parametric modeling software such as Rhino to achieve 3D visual design through BIM technology, adjust and optimize in real time to avoid design conflicts
Processing and Manufacturing	Manual lofting, manual cutting, low component accuracy (error > 5mm)	CNC cutting equipment processing, the accuracy can reach ±1mm, complex curved surface components can also be accurately formed
Installation and construction	On-site rough assembly, relying on experience and judgment, long construction period, large positioning error	3D coordinate positioning installation, segmented pre-assembly to reduce on-site work, hydraulic lifting, and other technologies to achieve precise installation of complex shapes
Complex modeling	Only regular geometric shapes can be completed, and complex curved structures are difficult to construct	It can realize special-shaped structures, such as hyperbolic and arc-shaped structures, such as the 270-degree arc-shaped suspension effect of the “Cloud Bridge” in Chengdu Financial City
Quality and efficiency	Much manual intervention, unstable quality, and a long construction period	Digital process control, stable quality, and shortened construction period by 30%-50%

Q5. How can the steel structure corridor be coordinated with the surrounding architectural style? Can the appearance be customized?
A: The steel structure corridor can be customized through the surface material and shape design. For example: ① The commercial block corridor can use glass curtain wall + metal carved board to create a modern and simple style; ② The historical block corridor can use imitation wood grain steel plate and blue brick finish to achieve a retro effect; ③ The scenic area corridor can combine natural elements, such as bark texture steel plate or vine climbing structure. Through color matching (RAL color card full color system optional) and lighting design, the steel structure corridor can be perfectly integrated into different environments.

Comparison Dimensions	Steel structure corridor construction method	Traditional construction method
Material properties	Made of high-strength steel, lightweight, high-strength, easy to transport, and install	Concrete, masonry, and other materials are often used, which are heavy and have high requirements for the foundation.
Construction period	Modular prefabricated components, on-site splicing and installation, fast construction speed, and construction period can be shortened by 30%-50%	The on-site pouring and masonry process is complicated, greatly affected by factors such as weather, and the construction period is long
Shape and style customization	Style customization can be achieved through surface materials (such as glass curtain walls, metal carved panels, imitation wood grain steel plates, etc.) and shape design, combined with RAL color card full color matching and lighting design, to flexibly adapt to different environments	The shape is limited by materials and craftsmanship, and it is difficult to adjust the style and meet diverse needs.
Environmental integration	Can be combined with natural elements (such as bark texture steel plates, vine climbing structures) to achieve organic integration with the environment	When blending with a natural or specific style environment, additional transformation is required, which is more costly.
Maintenance costs	Strong corrosion resistance, simple later maintenance, and low maintenance cost during service life	Prone to cracks, weathering, and other problems, frequent maintenance, and high cost

As a global leader in steel structure solutions, XTD Steel Structure has successfully built more than 50 landmark overpass and corridor projects in cities. Relying on BIM full-process control and modular construction technology, we provide customers with steel structure transportation solutions that are “fast delivery, beautiful and high-performance”, helping to efficiently connect urban spaces and usher in a new era of three-dimensional transportation.