What Is Split Tunneling?
A road tunnel refers to a building constructed to allow roads to pass through the ground or through the water.
Road tunnel
- This entry lacks an overview map . Supplementing related content makes the entry more complete and can be upgraded quickly. Come on!
- Chinese name
- Road tunnel
- Make up
- Cave body, cave door
- Features
- Through the formation or underwater
- Classification
- Mountain road tunnels, underwater road tunnels, etc.
- A road tunnel refers to a building constructed to allow roads to pass through the ground or through the water.
- The oldest road in the world
- According to the location of the tunnel, it is divided into mountain road tunnels, underwater road tunnels and urban road tunnels. In the selection of mountain roads with complicated terrain, the use of tunnels can provide the best route selection. Because the tunnel can overcome the obstacles of elevation, shorten the length of the line, reduce the slope and curvature, thereby improving the technical standards of the line. However, the construction cost of the tunnel is high, and technical and economic comparisons must be made during route selection. Underwater tunnels on urban roads instead
- Road tunnels should be designed as straight as possible. If it is necessary to set the curve due to the limitation of terrain or geological conditions, the radius of the flat curve should be set according to the grade of the road. Underwater tunnel as used
- As the vehicle emits harmful gases such as carbon monoxide, and the dust raised during the driving of the vehicle, the visibility in the tunnel is reduced. Except for extremely short tunnels, mechanical ventilation is required to dilute the harmful gases below the allowable concentration, Visibility required to ensure safe driving of cars. The amount of ventilation is determined according to the allowable concentration of harmful gases. For ventilation methods and systems, see Tunnel and Underground Engineering Ventilation.
- Road tunnels have special requirements for lighting. Disable long-distance front lighting in tunnels with heavy traffic; tunnel lighting facilities should allow moving cars and pedestrians to safely pass through the tunnel, reduce people's "underground feeling", and provide drivers with sufficient visual information. A light transition section can be set near the entrance of the tunnel, which does not make people feel that the brightness difference is too large when they enter the tunnel from the bright place in the open air, and can automatically adjust with the change of external brightness. Uninterrupted lighting can be used inside the tunnel.