Bridge design is known as a functional space and has facilitated access for people and vehicles from the past to the present. Bridges are mostly known as an urban structure that has the task of connecting two points to improve transportation in the city, or outside the city into the city.
Pedestrians and cyclists are the biggest users of urban bridges to deal with traffic and space-consuming cars. Also, pedestrian bridges and cyclists are a safe place for such people who suffer from the dangers of passing through crowded streets and rude drivers. Today, bridges are not considered just a structural element, and due to the aesthetics of architecture and urban planning, they have unique and meaningful design concepts.
Most of the metal aerial bridges used in our country are of the truss type with round sections. Sometimes we come across bridges with sheet girder sections. The main reason for this difference is that in the construction of a pedestrian bridge, the structure must bear In order to resist forces such as wind, live load and dead load (bridge structure) and the effects of temperature changes and natural disasters should be taken into consideration.
Types of Bridge
As we said, bridges have different types and fall into different categories; For example, the type of materials used in the construction of bridges can be a separate category for bridges. For example, metal bridges, each of which is made of different metals, according to the power, weight and lifespan in the considered environment, will have different uses and characteristics that are effective in choosing them; Therefore, it is necessary to check the types of bridges and their applications in order to be able to choose the right bridge for the design.
Wooden bridge
Wooden bridges are usually arched and built with supporting beams. Of course, you should know that the wooden bridge does not have much strength, so it will not last long. Due to their strength, wooden bridges are suitable for the passage of people, and for this reason, they are generally built temporarily for people to cross rivers or valleys.
Stone bridge
This type of bridge has very heavy materials and arched bridges are of this category. Stone bridges are very strong; But due to the weight of the material and its time-consuming nature, it is not of much use. Another reason why heavy bridges are not commonly built is the specialization of materials for this bridge, which requires a professional stonemason. In addition, the preparation of these materials and actually the construction of the structure requires a relatively long time, which destroys the economic justification of the construction of these types of bridges.
Concrete bridge
This type of bridge is arched and concrete is used in its construction. Since these bridges are very strong like stone bridges; But its materials are not as heavy as stone bridges, they are more practical than stone bridges. Also, because of its pressure resistance, concrete is a more suitable option than stone for building bridges.
Reinforced concrete bridge
Reinforced concrete bridges are much more practical. They are ordinary concrete bridges; Because they eliminate the components of the templates and this saves money. Reinforced concrete bridges are made in different ways, in each of them the method of pouring concrete is different, that is why they can be made in different shapes and sections. Prestressed concrete bridges >
If you have chosen this type of bridge, you can build bridges with larger spans at a lower cost. Prestressed concrete bridges have replaced metal and reinforced concrete bridges. Another positive feature of these bridges is that due to the materials that make them up, you can use new bridge building techniques for construction.
Metal bridges
Metal bridges have many shapes, and metal beams and metal arches are used to build them. Of course, light alloys are sometimes used in the construction of metal bridges. Since metal bridges get rusted over time, they put covers on them.
pedestrian bridge and car bridge
The bridge structure is considered one of the most expensive parts in the road construction project, and therefore, the basic and precise design This structure is very important.
The most common types of bridges are concrete bridges because these bridges are economically affordable. They are more beautiful in architectural design. Due to the new technologies used in increasing the strength of steel and increasing the compressive strength of concrete, these bridges have the potential to be built in high widths.
Needs to build pedestrian bridge
Types of Car and Pedestrian Bridges Based on Structural Elements
1- Flat bridges: which structural components bear the internal resistance of cutting, bending, twisting and axial force.
2- Truss bridges: The truss members of the bridge, which are usually made of steel, only bear compressive and tensile forces.
3- Arched bridges: If the bridge construction site allows the construction of an arched bridge foundation, this type of bridge has proven its superiority among other types of bridges. In this type of bridge, structural members bear almost pure pressure. In this type of bridge, it is very important that the path is not long so that the distance between the two ends of the arch does not increase, and this is evaluated by the index of the ratio of the horizontal distance to the height of the bridge, so the position and location of the bridge must be such that it provides this condition and this must Check carefully.
4- Suspended cable-stayed bridge: in these structures, the cables are responsible for bearing the net tension, and these bridges are divided into two general categories:
A- Suspension bridges: these bridges are economical for spans of more than 300 meters and are designed for spans of up to 3000 meters. In order to make this type of money lighter and more affordable, steel materials can be used in the crossing of this bridge.
B- Truss bridges: these bridges are designed with concrete passage and are designed for spans between 100 and 700 meters.
