In the tummy of the shield
We're approaching this shield made of “chinese iron” from an entrance to a subway tunnel. It can also be called “entry”, because, after a long 1. 5-km heat journey, we have, by accident, entered the interior of the shield。
The tunnel crosses in a circular shape, with a narrow footpath。
The tunnel's cross-section is round, and the shield cross-section is this shape. Here, people can only walk along the railings on both sides of the wall, which is very narrow, and both sides have to be sided when they meet. In the middle of the tunnel is a track in which, from time to time, a slag machine of more than one person has been driven and removed from the front. Here, people work around machines。
This is the point of reference for measurements。
"pipples" stacked on the ground
We crossed the top of the pipe planner, and i almost left my phone here。
And then i realized that this shelf, which i climbed at the risk of losing my hands, was called the “spread-painting machine”, and its purpose was to support by putting the “spread-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-past-a-past-past-past-past. The tube is made of steel and cement, thick and strong。
The most heavy pipe weighs eight tons and can easily be broken with the button above。
The most heavy pipe weighs eight tons and can easily be broken with the button above. So the large shield tube was suffocated with a vacuum straw so that the pull was evenly spread and the tube was not damaged。
Hydraulic jacks, a shield drive。
In the back of the plate of the shield, there was a circle of hydraulic jacks, and they “pushed” themselves forward against the side of the line that had been laid。
Foam blends are equivalent to “saliva”, which facilitates the chewing of knives and the mixing of rocks。
The shield is equivalent to a multiplication of earthworms, with the front blade “eats” of the earth, conveyor belts that excrete the earth from the back and continuously circulate “glue” (foams) and soften the soil less difficult to dig in. Where it passed, it formed a mid-empty tunnel with an inner diameter equal to its outer diameter。
Shield control room
There's a control room on the left side of the shield. It's no different from the control room for any complex transport: buttons, screens, telephones. The difference is that most transport control rooms can see the outside, where only screens can be used to reflect the scenes ahead. As if in the submarine。
The shield is active
To give us an intuitive view of the work of the shield, the engineer launched the shield. Despite being electrically driven (if driven by an internal combustion engine, oxygen is quickly out of the tunnel), the noise is still high, as it is the sound of a blade scratching the floors of the wall, the sound of various hydraulic structures, and of pumping work. The voice of the people has also increased. The engineer asked us to look for a reference point on the tube wall to see if the shield was moving slowly. But how easy can it be to stand on this huge thing that pushes a few centimetres per minute? We all gave up soon。
The face of contact between the tubes is sealed and the rubber is only a month away from the plant。
Scum belt
Through the control room, there is an expansive conveyor belt in the centre of the field of view, starting at the lower end of the blade plate and ending at the back of the shield. It was responsible for the removal of the cut-off rock and dirt to the dirt truck。
Excavated soil will be stored in the archive
Can you find the phone here
The final journey to the shield blade plate is to cross two arc beams one metre apart. It's covered in condensed water, very slippery. On top of it, you can only bow to your waist, and your head will come across the ceiling from time to time, with no grip on your hands. I asked the staff if there were no zippers in their pockets and if there was any way to find a cell phone that fell? Staff members looked down at the vertical pipes and the mud at the bottom and said to me that they should be found, but only the “casualities” of the mobile phone。
It's still a long and hot way back
Having visited the shield and experienced the great force of its operation, we returned from the original path, which is still 1. 5 km of heat. Clearly, the length of the tunnel is such that staff members are expected to travel from one day to another. Their hard work will come to light。
Evolving history of tunnel excavations
While the current operation of the shield is not immune to manpower, it is somewhat easier to dig in than in previous tunnels。
The tunnel excavations that preceded the industrial revolution have been ignored. Following the invention of the explosives alone, the tunnel was dug into the age of “drilling”. By definition, the “drilling” method consists of perforating the rock at the end of the tunnel first with a steel bar or a drill and then inserting explosives, detonators and fuses into the rock. The personnel were evacuated to safety and detonated. Until smoke runs out, personnel enter, clear the blasted rubble, secure the tunnel, and continue to “drille” ..
This method of tunneling is slow and dangerous. It often happens with a mute fire. Who's going to blast
At the shield production workshop, we can see more clearly from the outside the full picture and structure of the shield unit that was "just in the mountains" yesterday
In the 1980s, “drilling” was gradually replaced by large-scale mechanized ancillary operations consisting of rock-scrawling and lined-teams。
In the '90s, the complete cut-off of the industrialization operation, which is the shield we know。
Shield model
The front of the shield was to begin with the work on the thames tunnel in 1798, when the work was suspended because of the difficulty of the work. Brunol, an engineer from france, was inspired by the biological phenomenon and proposed the rationale for the shield to dig into the tunnel。
He found evidence of the drilling of insects such as the boat's beaver on board. Moreover, it also squirts a liquid on a hole wall and forms a protective shell against the humid expansion of the planks. The “open hand-drilling shield” designed by bruno was patented in england. In 1823, he established another thames bottom tunnel programme, which became the world's first shield. The body is a metal cylindrical, which contains complex mechanical equipment to drive the metal cylinder forward horizontally with a jack and to hold it together with a metal frame to prevent the caves and to carry out the construction of a line structure behind the metal frame. It can be said that the elements of the shield are basically available。
Map of the “first shields”. Source: tunnelling. Cn
This manual human shield was used for decades until the second-generation shield came into existence in 1876, using compressed air-driven force and mechanical force in lieu of manual excavation。
In 2008, our first complex shield with autonomous intellectual property rights was placed on the henan new village line and successfully applied in the construction of tianjin subway. The process of industrialization of our shields has thus begun。
Over the past 200 years, the development of shields has gone through five stages of development: 1. Mechanization, 2. Automation, 3. Digitalization, 4. Intelligence, 5. Humanization. In the “unmanned” phase of the future, artificial intelligence control will be used to dig in equipment that will allow for the drilling of tunnels that are empty, lightless and anaerobic. Operators can remain comfortably outside the tunnel and generally do not have to interfere with the work of the shield。
The ultimate aim of artificial intelligence is to break down jobs into steps and simulate human functions. For example, we have developed a shield unit called the "digge checking robot" that has the capability of detecting the status of the dig and cleaning and checking knives; the "digging rather than blade" robot is flexible enough to replace humans。
All kinds of knives
A smart shield can't be built without advanced blades. Alloy steel is not as sharp as we thought it would be, but it's a bit blunt, round-headed. According to the engineer, the shield was not cut, but crushed the rock by the push forward and the pressure of the blade。
The shield is like a train. The equipment is integrated inside
3. Shields of all types
When it comes to large underground works, you may think of a series of science fiction films: bio-crisis, the giant underground laboratory of the umbrella company, which may think of the tunnel that goes back and forth in the cemetery, even in outer space. For example, in "the big scrambling of the heavens and the earth " , bruce willis played by drilling workers went to a small celestial body to drill holes and explode to eliminate their threat to the earth。
In the opinion of professionals, tunnels and underground works in the film can be achieved by using existing combinations of circular blades. The need for different underground works can be achieved by finely clothed discs with large and small circles, which can form alien faults such as horseshoes, squares and triangles。
Fast anchoring set for large mine faults
It is now possible to hit horizontally, tilt upwards and tilt downwards. You can also hit down vertically later. Various applications are unexpected and impossible。
A full-faced well-drilling machine can be dug not only into the elevators of underground cities like the science-fiction film " elephant earth " , but also into special defence projects. The advantage of chinese enterprises lies in a comprehensive understanding of china's geological situation. China's geological situation is rich and complex and corresponds to the sum of the whole of europe。
Have you ever seen a chainsaw this big? Cutting stones is like cutting tofu
Super-engineering requires super-equipment, which can be envisaged in future super-engineering, such as the tsawashi railway (with more than 50 per cent of the length of the tunnel) or in the channel tunnel, which will necessarily require specially tailored super-equipment。
We are now in a position to produce self-programming machines such as earth-pressed balance shields, mud-water balance shields, rock tunnel digs, multi-model digs, pipers, vertical/slash well digs, heterogenesis, soft rock multifunctional digs, etc. They can cover multiple types of complex work, such as soft soil, hard rock, single-form, double-model, and multiple cross-section shapes, such as circulars, foreign shapes, straight lines, curves, slants, wells, multiple tunnel forms。
