The first steel arch bridge in the world is generally considered to be the New River Gorge Bridge in the United States. Here is an introduction to it and the characteristics and applications of steel arch bridges:
The New River Gorge Bridge is located in West Virginia, USA. It was completed in 1977. With a main span of 518 meters and a deck height of 267 meters above the canyon, it is one of the landmark buildings in West Virginia.
It was a pioneering work in the construction of steel arch bridges at that time. Its completion demonstrated the advanced technology and innovation ability in the field of bridge construction, and laid the foundation for the subsequent development of steel arch bridges. It also set a milestone in the history of bridge engineering with its large span and high altitude.
Strong Span Capacity: Steel arch bridges can make full use of the tensile and compressive properties of steel materials, enabling them to span large rivers, deep valleys and other obstacles. For example, the Chaotianmen Yangtze River Bridge in China has a main span of 552 meters, demonstrating excellent span capacity.
Lightweight and Aesthetically Pleasing: Steel has a high strength-to-weight ratio, making steel arch bridges relatively lightweight in structure. The curved shape of the arch is aesthetically pleasing, adding significant landscape value to the city. The Lupu Bridge in Shanghai is a typical example with its graceful curve.
Relatively Simple Construction: The components of steel arch bridges can be prefabricated in factories and then assembled on site. This not only shortens the construction time on site but also improves construction efficiency and quality.
Good Economy: Among long-span bridges, steel arch bridges are generally less expensive than suspension bridges and cable-stayed bridges. Moreover, their maintenance costs in the later stage are relatively low.
High Requirements for Foundation: Steel arch bridges have horizontal thrust, which requires high bearing capacity and stability of the foundation. It is necessary to reinforce the foundation. Construction on soft ground is difficult and costly.
Easy Corrosion of Steel: Steel is prone to rust and corrosion in the natural environment. Effective anti-corrosion measures such as painting and hot-dip galvanizing are required, and regular inspections and maintenance are also necessary.
Complex Structural Analysis: The mechanical properties of steel arch bridges are affected by geometric and material nonlinearities, making structural analysis and design calculations complex. Professional software and methods are required.
Urban Transportation: In urban areas, steel arch bridges are often used to connect different areas separated by rivers or valleys, such as the Lupu Bridge in Shanghai, which plays an important role in urban transportation and also becomes a famous scenic spot in Shanghai.
Intercity Connections: They are also important for connecting different cities. For example, some steel arch bridges across the Yangtze River and Yellow River connect cities on both sides, promoting regional economic development and cultural exchanges.
Scenic Spot Construction: Due to their beautiful appearance, steel arch bridges are often built in scenic spots to not only meet the transportation needs but also integrate with the natural landscape, becoming a highlight of the scenic spots.
High requirements for the foundation: there is horizontal thrust, the bearing capacity and stability of the foundation are high requirements, the foundation needs to be strengthened, and the construction on the soft soil foundation is difficult and costly.
Steel corrosion: steel in the natural environment is easy to rust corrosion, it is necessary to take effective anti-corrosion measures, such as painting, hot dipping zinc, etc., and regular inspection and maintenance.
Complex structural analysis: Mechanical properties are affected by geometric nonlinearity, material nonlinearity and other factors, and structural analysis and design calculation are complex, requiring professional software and methods.
Strong crossing ability: can give full play to the tensile and compressive properties of steel, across large rivers, canyons and other obstacles, such as the Chaotianmen Yangtze River Bridge main span of 552m, is one of the world's largest span steel arch bridge.
The structure is light and beautiful: the steel has high strength and light weight, which makes the bridge structure appear light, and the curve of the arch is beautiful, which can add landscape value to the city.
The construction is relatively simple: the components can be prefabricated in the factory and then transported to the site for assembly, which can shorten the site construction time, improve the construction efficiency and ensure the construction quality.
Good economy: In long-span Bridges, compared with suspension Bridges, cable-stayed Bridges, etc., the cost of steel arch Bridges is usually lower, and the later maintenance cost is also less.
