**: CCTV News.
Shield machine, also called a full-section tunnel boring machine.
It is a sharp weapon for "entering the ground".
However, in China, there are shield machines that can "climb steep slopes".
Let the huge and heavy "steel pangolin" climb upward.
It's not an easy task.
How does it climb up without slipping?
And what to do with the excavated slag?
Approaching togetherThe first station in my country will "climb a steep slope".
Full-section hard rock tunnel boring machine - "Yongning".
Explore the mystery of the domestic shield machine climbing over the hurdlesChina Railway Industry "Yongning" is China's first full-section hard rock tunnel boring machine that can "climb steep slopes", and is also known as "steel pangolin".Diameter 723 meters, with a total length of 122 meters, and a weight of 1,550 tons.
When a TBM excavates a tunnel, it can only "go straight" in the horizontal direction. For a TBM weighing 1,000 tons and consisting of more than 10,000 parts, every degree of slope rise is a great test from construction safety to component design.
Yongning" excavatedNo. 1 diversion inclined wellWith a total length of 927 meters and a vertical drop of more than 550 meters, it is also an important step in the construction of pumped storage power stations.
With a diameter of more than 7 meters and a slope of more than 36 degrees, there is no precedent for such a large tunnel to be excavated in the mountain by mechanized equipment, both at home and abroad. Next, the "Yongning" has to complete three major challenges
1 How does the "Yongning" climb up?
The climbing mode of the "Yongning" uses the structure of the creeper. The research team added two four groups of 8 "legs" in the front and back, with 16 "legs".
In order to allow the shield machine to safely "climb to the top of the mountain", more than 50 experts held nearly 40 coordination meetings, and after 40 months of research, design and testing, in August 2022, the first domestic shield machine that can "climb steep slopes" was successfully rolled off the assembly line.
2 How does the "Yongning" not "slip"?
When the 1,000-ton "Yongning" excavates into the mountain, the most important thing is to ensure the safety of construction and prevent falling.
There is a huge support on the wall of the cave, which is the double anti-slip system of the shield machine. This anti-slip system was tested for a month before being applied to the Yongning.
To this end, the research team also conducted an experiment in the field, in order to simulate the operation of the "Yongning" under extreme conditions, excavated a foundation pit with a diameter of 7 meters and a depth of 20 meters, and spent millions of yuan on the transformation.
Even if the iron plate walls on both sides are very smooth, the anti-slip system of the "Yongning" can still hold on, which is equivalent to a lot of safety factors.
As you can see from the red marks on the cave wall, the anti-slip system is reliable after many trials.
3 How does the "Yongning" transport the slag?
When the Yongning is excavating, the slag will accelerate down the slope, and if you are not careful, it will cause the gravel to splash, which is extremely risky. For this purpose, the engineers designed a slag chute that was then transported out of the tunnel by truck.
The research team has installed a water sprinkler system to spray water through this sprinkler head. During the process, gravel and dust are washed into the chute and flowed to the bottom of the tunnel.
The "Yongning" challenge was successful!
At 16:18 on December 14, the "Yongning" opened the No. 1 diversion inclined well. "Yongning" successfully completed the excavation task of No. 1 inclined shaft, filling the technical gap in the field of inclined shaft construction in China.
Soon, the Yongning and more than 2,000 builders will embark on a new journey to dig the No. 2 diversion inclined shaft.
Seven out of every 10 EPBs in the world come from China. Today, Chinese engineers have innovated the shield machine, which could only move horizontally, to be able to go up, down, and turn around
Topic |Liu Fan.
Edit |Liu Fan.
Editor-in-charge |Wang Zihan.