How can a ＂underground＂ shield machine climb a mountain？ The Secret Behind is →

shield machineAlso called full-face tunnel boring machine.

This 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 upwards.

It’s not an easy task.

How does it climb up without slipping?

How to deal with the excavated slag?

Approaching togetherThe first one in China will "climb the steep slope"

Full-face hard rock tunnel boring machine-"Yongning"

China Railway Industry "Yongning" is the first full-face hard rock tunnel boring machine in China, also known as "steel pangolin".It has a diameter of 7.23 meters, a total length of 122 meters and a weight of 1550 tons.

When a common roadheader digs a tunnel, it can only "go straight" in the horizontal direction. For a roadheader with a weight of 1,000 tons and more than 10,000 parts, every time the slope rises, it is a great test from construction safety to parts design.

"Yongning" excavatedNo.1 diversion inclined shaft,The total length is 927 meters, and the vertical drop is over 550 meters.It is an important step in the construction of pumped storage power station.

The diameter is over 7 meters and the slope is over 36 degrees. There is no successful precedent at home and abroad to dig such a large tunnel in the mountain by mechanized equipment.Next, Yongning has to complete three major challenges ↓

1 How does Yongning climb up?

The climbing mode of Yongning relies on the structure of Parthenocissus tricuspidata. The research team added two four groups of eight "legs" before and after, and there were 16 "feet".

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In order to make the shield machine "climb to the top of the mountain" safely, more than 50 experts held nearly 40 coordination meetings. After 40 months of research, design and test, in August 2022, the first domestic shield machine that could "climb the steep slope" was successfully rolled off the assembly line.

2. Why didn’t Yongning "slide"?

When the 1000-ton Yongning is heading up the mountain, the most important thing is to ensure construction safety and prevent falling.

There is a huge support on the wall of the cave, which is the double anti-slip system of shield machine. This anti-skid system was applied to "Yongning" after a month of limit test.

To this end, the research team also made an experiment in the field. In order to simulate the operation of Yongning under extreme conditions, a foundation pit with a diameter of 7 meters and a depth of 20 meters was excavated, and the renovation cost millions of yuan.

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Even if the iron plates on both sides are smooth, the anti-skid system of Yongning can still hold still, which is equivalent to a much higher safety factor.

It can be seen from the red mark on the cave wall that the anti-skid system is reliable after many tests.

3. How did Yongning ship carry out the slag?

When the "Yongning" is driving, the generated slag will roll down the slope at an accelerated speed. If it is not careful, it will cause the gravel to splash, which is extremely risky.To this end, engineers specially designed a slag chute, which was then transported out of the tunnel by truck.

The research team specially installed a sprinkler system to spray water through this sprinkler head. In the process, gravel and dust will be washed in the chute and flow to the bottom of the tunnel.

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At 16: 18 on December 14th, Yongning opened the No.1 diversion inclined shaft.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, "Yongning" and more than 2,000 builders will embark on a new journey and excavate the No.2 diversion inclined shaft.

Seven out of every 10 shield machines in the world come from China.Today, engineers in China have innovated the shield machine, which can only move horizontally, to be able to go up, down and turn. Praise!