Bridges are crucial structures in transportation systems, serving to connect different parts of land that are separated by rivers, valleys, and other obstacles. A bridge consists of various components that work together to ensure its safety and stability.

These components can be broadly classified into five major and five minor components.

The major components include the bridge span structure, bearing system, bridge pier, bridge abutment, and foundation. The minor components include the bridge deck pavement, drainage and waterproofing system, railing, expansion joint, and lighting.

The bridge span structure is the most important component of the bridge, as it is responsible for bearing the weight of the vehicles and people crossing over it. The bridge span structure can be made of various materials such as steel, concrete, or wood.

The bearing system is another crucial component that supports the superstructure and transfers the load to the bridge pier. It should be able to accommodate any displacement expected due to load, temperature, or other factors.

The bridge pier is a vertical structure that supports the bridge span structure, while the bridge abutment supports the bridge span structure on both sides and transfers the load to the foundation.

The abutments are usually located on both sides of the river, with one end connected to the embankment to prevent it from slipping and the other end supporting the superstructure of the bridge span. The foundation is responsible for ensuring the stability of the piers and transferring the load to the structural part of the foundation.

In bridge engineering, the main challenge is to overcome obstacles such as rivers and seas, mountains, and other natural barriers to ensure a smooth flow of transportation. Water, in its various forms, presents a major challenge in the design, construction, and maintenance of bridges.

Therefore, understanding the behavior of water and making effective use of it is critical to the success of bridge engineering.

Bridge foundations are usually drilled in the ground or excavated in pits, and since soil contains water in different forms such as free water, pressurized water, and ionic water, it is essential to have effective measures in place to manage water during excavation.

The physical state of the soil changes from an equilibrium state to an unbalanced state during excavation, leading to phenomena such as the collapse of the pit wall, seepage of the foundation, bulging of the pit bottom, and even the settlement or tilting of adjacent buildings.

When excavating large pits, it is important to use water collection pits drainage to manage water. In cases of large seepage, water glass, quick-setting concrete, and other materials may be used to block the seepage channel.

In the case of clay soil with high plasticity index or rich in silt, no open excavation should be used to release the slope, and special construction plans should be put in place.

In the construction of the river pile foundation and bearing, a steel cofferdam is usually used to sink the bridge site in the nearest location of the land factory. The buoyancy of water is used in the process, and mud is filled in the hole during drilling.

The mud is proportioned based on the nature of the soil, and it helps to maintain a large head while preventing the collapse of the hole wall.

Bridges are essential structures in transportation systems, and their construction and maintenance require careful planning and effective management of different components.

Effective measures should be put in place to manage water during excavation, and special construction plans should be implemented for different soil types.

With careful planning and execution, bridges can effectively connect land areas and facilitate the flow of people, vehicles, and materials.