The tunnel that the train passed in 5 seconds took 6 years to get through. Why did it take so long?

Lanzhou-chongqing railway Humaling Tunnel (173m) took six years to get through. There is a reason why it took so long. Let me tell you in detail:

In September, 2008, the lanzhou-chongqing railway project was officially started. Upon completion, it will run through Gansu and Chongqing, with a total length of 800KM, passing through 22 counties and cities in Gansu, Shaanxi, Sichuan and Chongqing.

Although the distance is not long, the construction difficulty should not be underestimated, because there are many mountains and rivers to cross along the way, so there are 200 light tunnels and 300 bridges. It is not particularly difficult to dig a tunnel under normal circumstances, but it is another matter if you dig a tunnel in a stratum rich in water, silt and fine sand. Digging a tunnel in this geological condition is like drilling a hole in tofu brain. If you are not careful, the whole section may collapse. The most typical example of "making a hole in tofu brain" is Humaling Tunnel in Lanzhou, Gansu Province, which can be said to be a veritable "gate of hell".

Subdivided rock mass is like powder. Without superb technology, let alone opening a tunnel, even if a stone is taken out from it, it is in danger of collapse.

This 173 meter mountain really gives us a problem, because the soil is too loose and the shovel is hard, even the top foreign "experts" can't do anything about it. The most exasperating thing is that they just stood by and gloated. Those "experts" just want to see our jokes.

At this time, expert Li Xia came to the construction site. He and his father Fu were ordered to be chief engineers and surveyors of Humaling Tunnel. They took over the most difficult inclined shaft No.1 and No.2. The distance between the two wells is173m, which is very difficult to get through. The construction workers were helpless and shook their heads.

However, Li Xia has an indomitable spirit. He faced the difficulties and vowed to get through the last paragraph.

After careful consideration, Li Xia finally pioneered a technology called "Jiugongge Operation Method", which perfectly solved this world problem. The so-called "nine-grid operation method" is to divide a large working face into several parts, divide nine small working faces and excavate at the same time, and carefully complete the excavation task of each working face under the condition of ensuring the stability of rock stratum.

Many things happen. From June 2065438 to June 2007, after six years of day and night fighting, the last section of Humaling Tunnel was completed. Three months later, the whole line of lanzhou-chongqing railway was connected, and a series of trains roared through the Humaling Tunnel, once known as the "Gate of Hell".

There is another person whose name will go down in history forever, and that is the expert "Li Xia".

Everyone cheered and admired the experts from Li Xia. The news soon spread, and those "experts" who once wanted to see our jokes were dumbfounded, surprised and ashamed at the same time. This time, they were severely beaten in the face.

The completion of lanzhou-chongqing railway has condensed the hard work and sweat of our builders, engraved the wisdom and courage of experts, and demonstrated the spirit of great country craftsmen. At the same time, Chinese builders, known as "infrastructure enthusiasts", once again enjoy a high reputation abroad, go to the world and praise them!