Tunnels have become an important part of modern transportation. Metros, highways, submarines, etc. are widely used. Just like the middle section of the Hong Kong-Zhuhai-Macao Bridge, the submarine tunnel is used. The advantages of tunnels are many. influences. 2. It will not be affected by bad weather such as typhoon. The disadvantage is that the construction is difficult. In terms of infrastructure construction in China, the last thing we are not afraid of is the difficulty.

How does it work on the seabed at a depth of tens of meters?

At present, the methods of tunnel construction mainly include blasting method, immersed tube method and shield method. Among them, the blasting method is the most simple and crude, and it is the conventional method used in the excavation of ordinary underground tunnels. First, use a rock drill to drill holes in the designated positions, and then put explosives in the drilled holes and then detonate them. Finally, the residue is transported out, the inner wall of the tunnel is lined, and the process is repeated.

blasting

The immersed tube method is currently the most commonly used method for building subsea tunnels. This method is to build the pipeline on the shore, plug the two ends, and then sink it to the seabed for docking. The docking process needs to be precise, and the error should not exceed two millimeters. In order to prevent the subsea tunnel from floating, finally, gravel and fine sand must be laid above the tunnel, so that the contact area between the pipeline and the seawater is reduced, which in turn reduces the corrosion of the pipeline by the seawater. The Hong Kong-Zhuhai-Macao Bridge subsea tunnel in China was constructed using the immersed tube method. It is the longest and only deep-buried immersed tube tunnel in the world at this stage.

Immersed tube method

The last method is the shield method. A shield machine needs to be used, which is assembled on the construction site. A giant cutter head is installed on the head of the machine, which is driven by the hydraulic system to move forward slowly. It is a high-tech machine that can dig rocks and lay pipes in one go. This is also the most efficient method, and the construction is not affected by weather conditions such as details, wind and rain. Please long-press and like, strongly recommend it, and like China's infrastructure, you have worked hard! Follow Xinyuezhi to learn more about scientific popularization.

shield method

Will the undersea tunnel leak?

This problem has always been a concern for many people. What should I do if the vehicle is running in the tunnel and there is water leakage? First of all, let's see if there is a possibility of water leakage. For example, the Hong Kong-Zhuhai-Macao Bridge, the subsea tunnel section is not suspended in seawater, but sunk into the silt on the seabed, and is filled with a large amount of gravel, which will make the tunnel and the As little contact with sea water as possible, the possibility of water leakage will be greatly reduced. The sealing material used at the connection of the two sections of the pipeline is also specially treated and has strong corrosion resistance, even stronger than waterproof concrete. In addition, the engineer also designed escape doors, one every 135 meters. Even if there is a real leak, the sea water cannot be filled at once. No matter forward or backward, the maximum distance from the escape door is 70 meters. There is escape time. The escape door The passage will lead directly to the artificial island. In fact, after careful design by the designer, the possibility of water leakage in the submarine tunnel is almost zero, and there is no need to worry too much.