Why was the tunnel being dug? Why build tunnels

The railway had to pass through many high mountains, and tunnels had to be excavated, among which the two tunnels of Juyongguan and Badaling were the most arduous. Juyongguan is a high mountain with thick rock formations, so Zhan Tianyou decided to adopt the method of chiseling from both ends to the middle at the same time. The spring at the top of the mountain seeped down, and the tunnel was full of mud.

There was no pumping machine on the construction site, so Zhan Tianyou took the lead in carrying a bucket to drain the water. He often lived and ate with the workers and did not leave the construction site. The Badaling Tunnel is more than 1,100 meters long, three times as long as the Juyongguan Tunnel.

He consulted with the old workers and decided to use the central shaft sinking method. A shaft was drilled from the top of the hill down, and then excavated at both ends, and both ends were also constructed at the same time, shortening the construction period by half. Dig from the north and south ends of the mountain at the same time, and dig a large well in the middle of the mountain, and then dig at the north and south ends in the well.

This not only ensures the quality of construction, but also accelerates the progress of the project. When digging a hole, a large number of stones are dug by hand with a spade, and the spring water gushing out has to be picked out one by one. He also encouraged everyone to say:

The Beijing-Zhangjiakou Railway is the first railway we built with our own people and our own money, and the eyes of the whole world are looking at us, and we must succeed! "Whether success or failure, it is by no means our own success and failure, but the success and failure of our country! ”<

How the tunnel is built can be said clearly in a few words, and different tunnels use different methods, such as mountain tunnels, subway tunnels, and undersea tunnels. In order to facilitate the public's understanding, I take several typical construction methods in the construction of mountain tunnels, submarine tunnels and subway tunnels as examples, and take the key steps in a general way, and some of the specific and detailed steps are directly omitted. First, according to the designed position, the door arch should be erected, and then the concrete should be poured.

Then drive into the large pipe shed, that is, the row of steel pipes above, the length of 10-30 meters depending on the situation, and then inject cement slurry into it with high pressure after driving, its advantage is that the soil and steel pipe cement slurry are bonded together to form an arch-shaped reinforced soil. In this way, it will not collapse easily when digging. That's probably what it looks like when it's done.

2. Dig a hole and do the first layer of support.

Second, dig the hole body, do the first layer of support tunnel digging time according to the quality of the rock to choose different methods, digging size and way is different. Specifically, if it is a hard and intact rock, then the tunnel can be dug as big as it is, and if it is soil like the one shown above, it will be divided into three or four pieces. This is a tunnel of the new Chengkun line, which is dug in four parts, and now I see that it is dug on the left, and there is also the lower left, the upper right, and the lower right to be dug.

Generally speaking, the rock tunnel will not collapse immediately after digging, and the soil tunnel will not collapse immediately due to pre-grouting or anchoring (that is, the steel bar of the thick point), at this time, the worker will follow the instructions of the measurement, put some steel arches that are pre-made into the outline of the tunnel and place them in the designated position, after the steel arch is placed, the gap between the two arches should be put with steel mesh, welded, and the anchor should be driven laterally. After that, it's time to spray concrete. If something goes wrong, you have to move on to the next step.

1. What is a tunnel?

Tunnels are artificially excavated underground passages, which are often used in construction fields such as roads, railways, subways, and mines. The advantage of the tunnel is that it can directly pass through obstacles, shorten the distance, reduce the difficulty of construction, and improve traffic efficiency.

2. Why build tunnels?

There are many reasons for the construction of tunnels, mainly the following:

1) Complex terrain: the terrain conditions such as steep mountains, turbulent water flows, and staggered rivers make it very difficult to build road surfaces, while tunnels can directly pass through mountains and water flows, making the route more convenient;

2) Environmental protection requirements: The traditional construction of roads and railways not only needs to level the land, but also usually needs to cut down large areas of forest, causing environmental damage. Tunnels can protect the environment to the greatest extent and do not damage natural resources;

3) Safety requirements: The tunnel can strengthen the mountains on both sides of the tunnel, so as to reduce the risk of natural disasters such as landslides, landslides, and debris flows to the building;

3. The technology and difficulty of tunnel construction.

The construction of tunnels requires the use of certain technical means, and the general steps are as follows:

1) Planning and design: scientific and reasonable planning and design according to the actual terrain and environmental conditions;

2) Land acquisition: purchase the required land to ensure the effectiveness and safety of construction;

3) Selection of drilling equipment: tunnel construction needs to strictly control the direction and depth, so it is necessary to purchase suitable drilling equipment;

4) Master the geological characteristics: the geological conditions of tunnel construction are very important, and different geological conditions need to adopt different construction methods;

5) Construction management: The tunnel construction should achieve the stability, timely management and smooth coordination of the construction management team, and carry out construction quality control in strict accordance with the inspection and acceptance of the VCR project and the construction progress.

4. Influencing factors of tunnel construction.

There are many influencing factors for the construction of tunnels, including topography, mining area, hydrology, permeability, freeze-thaw, physical mechanics and other factors.

In the process of tunnel construction, if there is no scientific and reasonable consideration and planning, it will cause a series of adverse consequences, such as poor excavation quality, tunnel erosion, etc.

5. Prospects for tunnel construction.

With the acceleration of the country's economic development, the demand for transportation is also growing, and the much-anticipated "Belt and Road" will build new land-sea roads, which highlights the importance of building tunnels. In the future, the direction of tunnel construction will be more extensive and diversified, and it is necessary to realize the high-quality realization of various constructions such as subway network and intercity highway in the process of urbanization, and at the same time, the protection and environmental protection function of the tunnel and the reduction of the impact on the original ecological life are also more and more important.

Since ancient times, building roads and bridges has been seen as a measure for the benefit of the people. In modern society, roads and bridges are also considered to be the foundation of economic development, and they are as important as the blood vessels in a person. However, when people build roads or railways, they will inevitably encounter obstacles from mountains and rivers.

In the case that the traditional "opening roads in the mountains and building bridges in the water" are difficult to implement, the construction of tunnels may be the most practical and effective method. A railway or road tunnel through a mountain is much simpler than a winding railway or road; And when the sea blocks the way and it is inconvenient to build a bridge, the undersea tunnel is like the magic of Sun Wukong to go to the sky and the earth, so that we can reach the other side smoothly.

In addition, the tunnel has many functions, such as a tunnel used for underground drainage or water supply in the city, a tunnel for laying gas pipelines or large transmission lines, a subway tunnel, a diversion tunnel for agricultural irrigation, and a special tunnel for national defense and military use.

Why are tunnels being built, and why are people called people?

Hello dear. Why should tunnels be built, and why should people be called people, because tunnels have many functions, such as tunnels used for underground drainage or water supply in cities, tunnels for laying gas pipelines or large transmission lines, subway tunnels, water diversion tunnels for agricultural irrigation, and special tunnels for national defense and military purposes. When people build roads or railways, they will inevitably encounter high mountains and rivers.

In the case that the traditional "opening roads in the mountains and building bridges in the water" are difficult to implement, the tunnel may be the most practical and effective method. Thank you for your consultation, I hope this service can help you, you can click on my avatar to follow me, and if you have any questions in the future, please consult me again, and finally wish you a happy life! <>

Tunnel refers to the passage dug in the existing building or earth and stone structure, and the structure of the tunnel includes two parts: the main building and the ancillary equipment. The main building is composed of a cave body and a door, and the ancillary equipment includes a car shelter, fire protection facilities, emergency communication and anti-drainage facilities, and a long tunnel with special ventilation and lighting equipment.

Tunnels: Norway's Lodal Tunnel: The world's longest road tunnel with a length of kilometres.

The Gotthard Tunnel in Switzerland: the third longest road tunnel in the world with a length of kilometres, connecting the Swiss cantons of Uri and Ticino.

The Anglo-French Undersea Tunnel: The world's second longest railway tunnel, with a length of kilometers and kilometers of seabed length, it is also the world's longest undersea tunnel, connecting the United Kingdom and France across the English Channel.

Seikan Tunnel: The world's longest railway tunnel, with a total length of kilometers and a length of kilometers under the sea. The tunnel crosses the Tsugaru Strait and connects Hokkaido and Honshu in Japan.

Explanation: On: Activated.

Excavation: excavation (tunnels, etc.).

Definition 1: A horizontal passage with ground entrances and exits at both ends of a trench in the formation.

Definition 2: A long passage dug into a mountain or below the ground.

Zhan Tianyou adopted the method: from the top of the mountain down vertically, and then excavated out of the mountain (the first type), and at the same time the people outside the mountain chiseled inward (the second type).