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What do you mean the train goes into the hole?

1, when a train enters the tunnel, it means that the train enters the tunnel, and the railway tunnel is a passage specially used for train transportation. When the railway crosses the mountainous area, it is necessary to overcome the elevation obstacle due to the limited traction capacity and the maximum slope limit (less than 24%). Mountain tunnel is a reasonable choice, which can shorten the line, reduce the slope, improve the operating conditions and improve the traction capacity.

2. According to its location, it can be divided into three categories: mountain tunnels that cross mountains or hills to shorten the distance and avoid large ramps; An underwater tunnel that passes under a river or seabed in order to cross a river or strait is called an underwater tunnel. In order to meet the needs of railway crossing big cities, it is called urban tunnel.

3. Construction method: During tunnel excavation, small pilot tunnel is used to advance, and then full-face blasting is used to follow up. In the same tunnel, the level guide is advanced, full-face reaming is adopted, the surrounding rock of smooth blasting has a good arch shape, and then support and lining are carried out. The quality is high and the progress is fast, which can ensure that the lining is beautiful inside and beautiful outside. The waterproof board is installed to effectively play a waterproof role and ensure the lining is impervious and leakproof.