Tunnel classification is distinguished from different angles, and different classification methods can be derived. According to the stratum, they can be divided into rock tunnels and earthy tunnels. According to their location, they can be divided into mountain tunnels, urban tunnels, and underwater tunnels. According to construction methods, they can be divided into mining methods, cut-out methods, and shield methods. According to the buried depth, it can be divided into shallow and deep buried tunnels; according to the section form, it can be divided into circular, horseshoe-shaped, rectangular tunnels, etc .; common tunnel types are mainly traffic tunnels, hydraulic tunnels, municipal tunnels, etc. Mining tunnels, let’s take a closer look at these types of tunnels.
A traffic tunnel is the most widely used type of tunnel. Its role is to provide passages for transportation and pedestrians to meet the requirements of smooth traffic lines. Generally, it includes the following types.
(1) Highway tunnel
A road tunnel is a passage dedicated to automobile transportation. With the development of social economy and production, a large number of highways have appeared, and higher standards for road construction technology have been proposed. Straight lines, gentle slopes, and spacious roads are required. Therefore, when roads cross mountain areas, a large number of roads appear. Tunnel scheme. The construction of the tunnel plays an important role in improving the technical status of the highway, shortening the running distance, increasing transportation capacity, and reducing accidents.
(2) Railway tunnel
A railway tunnel is a passage dedicated to train transportation. When the railway passes through mountainous areas, it is necessary to overcome the elevation obstacles. Due to the gentle slope limitation of the railway, the maximum slope limit is less than 2.4% (dual-machine traction). These mountainous areas cannot be bypassed due to the terrain and often cannot obtain the required elevation through the exhibition line. At this time, excavating a tunnel across a mountain is a reasonable choice, and its effect can shorten the line, reduce the slope, improve operating conditions, and increase the traction number.
(3) Underwater tunnel
Underwater tunnels are tunnels built on rivers, rivers, lakes, seas, and oceans, and are used by cars and trains for transportation. The options available are bridges, ferries and tunnels. Underwater tunnels are a good solution. Their advantages are that they are not affected by climate, do not affect navigation, occupy less land, and do not expose traffic facilities during wartime. More and more people are favored, the disadvantage of underwater tunnels is the higher cost.
The subway is a passageway for train transportation built in urban strata to solve urban traffic problems. The subway is one of the effective ways to solve traffic congestion and vehicle congestion in big cities. As the subway can transport a large number of passengers quickly, safely, and on time, it has become a powerful means to resolve traffic contradictions in large cities. Can improve the city’s traffic conditions and reduce traffic accidents played an important role.
(5) Shipping tunnel
A shipping tunnel is a passage built specifically for shipping transportation. When the canal needs to cross the watershed, a powerful way to overcome the elevation is to build a canal tunnel, which has the advantages of shortening the voyage, reducing operating costs, straightening the river, and greatly improving shipping conditions.
(6) Pedestrian tunnel
Pedestrian tunnels are passages dedicated to pedestrians. It is generally built in the downtown area, crossing streets, or crossing railways, highways, and other pedestrians, crossing traffic, dense vehicles, and occasional accidents. The role of the pedestrian tunnel is to relieve the pressure on the ground, reduce traffic accidents, and facilitate pedestrians.
Hydraulic tunnels are an important part of hydraulic engineering and hydropower hub groups. Hydraulic tunnels include the following:
(1) Water diversion tunnel
A water diversion tunnel is a tunnel constructed by introducing water into the generating set of a hydropower station or mobilizing water resources. The water introduced by a diversion tunnel is the power resource of the generating set of a hydropower station. Therefore, as a diversion construction project, the pressure of the inner wall is generally required, but sometimes it is only partially passing through. Water pressure and diversion tunnels can be divided into pressure tunnels and non-pressure tunnels.
(2) Tail water tunnel
The tail water tunnel is a tunnel constructed by sending out the waste water discharged from the hydropower generating units.
(3) Diversion tunnel or flood discharge tunnel
A diversion tunnel or a spillway tunnel is a tunnel constructed to divert water from a water conservancy project and supplement the spillway after the spillway flow exceeds its limit. It is an important building for water conservancy projects, and its role is mainly to release floods.
(4) Sand drainage tunnel
Desilting tunnels are tunnels built to wash away silt in reservoirs. It is an integral part of the reservoir building, and its role is to use sand-draining tunnels to carry the sand wrapped out of the reservoir. It is also used to empty the water in the reservoir during inspection or repair.
In urban construction and planning, underground tunnels are constructed by making full use of the underground space and placing various municipal facilities under the ground, called municipal tunnels. Municipal tunnels are closely related to people’s life, work and production in the city, and play an important role in ensuring the normal operation of the city. The main types are:
(1) Water supply tunnel
The water supply tunnel is a tunnel built for the laying system of urban water pipe network. In cities, orderly and rational planning and layout of water supply pipelines that are closely related to people’s lives and production is an important task of urban municipal infrastructure. It is required not to damage the urban landscape, occupy the ground, and avoid human damage. Therefore, it is a reasonable choice to construct underground tunnels to accommodate these pipes.
(2) Sewage tunnel
Sewage tunnels are tunnels built for urban sewage drainage systems. Except for the part of urban sewage that is seriously polluted and reused or discharged, most of the sewage needs to be discharged into rivers outside the city, which requires underground sewage tunnels. This type of tunnel usually uses its own diversion and drainage. At this time, the shape of the tunnel is mostly oval. It may also be that a sewage pipe is placed in the tunnel to discharge sewage. At the entrance of the sewage tunnel, there are mostly slag blocking barriers to block floating debris out of the tunnel so as not to cause blockage due to influx.
(3) Pipeline tunnel
Pipe tunnels are tunnels built for urban energy supply (gas, heating, hot water, etc.) systems. The pipeline tunnel in the city is to place the pipeline that transports energy in the constructed underground tunnel. After leakage prevention and thermal insulation treatment, the energy can be safely transported to the production and home destination.
(4) Line tunnel
Line tunnels are tunnels built for power and communication systems. In the city, in order to ensure that power cables and communication cables are not damaged or damaged by people’s activities, and to avoid the impact of high altitudes on the urban landscape, special underground tunnels are built to house them: In modern cities, the above four common characteristics According to the city’s layout and planning, a municipal tunnel is built into a common tunnel, called a “common pipe trench.” The common pipe trench is a symbol of the scientific management and planning of modern urban infrastructure, and a scientific method for the rational use of urban underground space. It is also the direction for the planning and construction of urban municipal tunnels.
(5) Civil defense tunnel
Civil air defense tunnels are air defense evacuation tunnels built for wartime air defense purposes. Civil air defense works were built in cities to prevent the need for war air strikes. Civil air defense works are used for shelter in emergency situations. Therefore, the general requirements of people on the living environment should be considered during construction. In addition to drainage, ventilation, lighting and communication equipment, storage of drinking water, food and Necessary ambulance equipment. Explosion-proof and anti-shock wave devices need to be set at the entrance of the cave.
In mining, the tunnels from the outside of the mountain to the ore deposit and transporting the mined ore are realized through the construction of tunnels. Their functions are mainly for mining, and there are the following.
(1) Transportation laneway
Tunnels to the mountains lead to the ore deposits, and roadways are gradually opened to the various mining faces. The former is called the main roadway, which is the main entrance and exit of the underground mining area and the main transportation trunk road; the latter is distributed like a tree shape and is distributed to each mining face. Such a roadway is usually supported temporarily and is only needed for the operator’s mining work.
(2) Water supply tunnel
The clean water sent is used by mining machinery, and the waste water and standing water are pumped out of the cave.
(3) Ventilation tunnel
Underground mine tunnels usually pass through the ground with harmful gases, exhaust gas from mining machinery, and gas exhaled by workers, making the air in the tunnels dirty. If the gas in the formation contains gas, it will endanger human safety. Therefore, to purify the air in the roadway and create a good working environment, a ventilation roadway must be set up to remove harmful gases and replenish fresh air.
In summary, tunnel engineering has been applied in many fields and has become an important component of national construction, people’s life and production. In recent years, there have been considerable developments in tunnel technology, but there are still many problems and areas to be studied and improved.