What is the diameter of the world s largest EPBM? When was the EPB invented?

Diameter meters.

On October 26, the slurry balance shield machine with a diameter of up to one meter was officially rolled off the assembly line in the shield workshop of China Railway Equipment, and the equipment will be applied to the Shantou Bay Tunnel Project. This is also the largest diameter slurry balance shield machine independently designed and manufactured by China so far, and its successful launch line has broken the situation that foreign brands have dominated the world for many years.

The ultra-large diameter slurry balance shield machine has the characteristics of small impact on the surrounding environment, high degree of factory operation, high accuracy of ground subsidence control, safety and speed, and has unique advantages in the construction of a series of cross-river and cross-sea tunnels in China, and is the high-end equipment that is the focus of development in the "Made in China 2025" plan.

In addition, the shield machine can integrate tunnel boring, soil transportation, segment assembly, etc., and has the advantages of high degree of automation, safe construction, no obstruction to navigation, and no climate impact.

The world's largest diameter shields are Herrenknecht's S-317 and S-318 slurry balance shields, with a diameter of meters.

The shield machine, also known as the tunnel boring machine, is customarily called shield for soft soil strata and TBM for rock strata in China. The tunnel construction with the shield machine has the characteristics of high degree of automation, manpower saving, fast construction speed, one-time tunneling, not affected by climate, land subsidence can be controlled during excavation, the impact on ground buildings can be reduced, and the ground traffic is not affected when excavating underwater.

According to the working principle, the shield machine is generally divided into hand-excavated shield, extrusion shield, semi-mechanical shield (local air pressure, global air pressure), mechanical shield (open chest cutting shield, pneumatic shield, slurry pressurized shield, earth pressure balance shield, mixed shield, special-shaped shield).

On September 27, 2020, the "Jinghua" ultra-large diameter shield machine rolled off the assembly line in Changsha. The TBM is 150 meters long, has a total weight of 4,300 tons and a maximum excavation diameter of up to one meter. This is the largest diameter shield machine developed in China so far, and it will participate in the construction of the East Sixth Ring Road reconstruction project in Beijing after leaving the factory.

It was first developed by a French engineerBrunet was invented in 1842.

Inspired by the phenomenon of observing maggots drilling holes in the wood of ships and expelling a slime from the body to strengthen the caves, the French engineer Brunel began to study the shield construction in 1818, and in 1825, he used a rectangular shield to build the world's first underwater tunnel (wide and high) under the River Thames in London Mountain, England. It encountered great difficulties in the construction process, and was twice flooded by the river, and it was not completed until 1835, when an improved shield was used, and it was completed in 1843. Later, in 1865, Barlow built a tunnel at the bottom of the Thames with a circular shield with a diameter of one metre.

In 1847, in the construction of the south line of the London Underground Railway City, the British Gretelhead used the pneumatic shield method for the first time in the clay layer and the water-bearing sand layer, and for the first time pressed the grout behind the lining to fill the gap between the shield tail and the lining, creating a relatively complete pneumatic shield construction technology, laying the foundation for the modern shield construction and promoting the development of the shield construction.

The basic principle of operation of the EPB is that a cylindrical steel component excavates the soil while advancing along the axis of the tunnel. The shell of the cylindrical component acts as a shield, which acts as a temporary support for the excavated unlined tunnel section, bearing the pressure of the surrounding soil layer and sometimes the groundwater pressure and keeping the groundwater out. Excavation, earth drainage, lining and other operations were carried out under the cover of shields.

1. The excavation of the shield machine: the hydraulic motor drives the cutterhead to rotate, and at the same time opens the propulsion cylinder of the shield machine, and pushes the shield machine forward, with the forward advancement of the propulsion cylinder, the cutterhead continues to rotate, and the ballast that is cut down fills the soil silo, at this time, the screw conveyor is started to discharge the cut muck to the belt conveyor, and then transported to the soil box of the muck truck by the belt conveyor, and then transported to the ground through the shaft.

2. Control the amount of soil discharge and the speed of soil discharge in the tunneling: when the ballast in the soil bin and the screw conveyor accumulates to a certain amount, the resistance of the muck cut from the excavation face into the soil bin through the knife groove increases, when the earth pressure of the soil bin is balanced with the earth pressure of the excavation face and the water pressure of the groundwater, the excavation face can remain stable, and the ground part corresponding to the excavation face will not collapse or uplift. In this case, as long as the amount of muck conveyed from the screw conveyor and the silo is balanced with the amount of muck in the cut flow silo, the excavation work can proceed smoothly.

3. Segment assembly: After the distance of the shield machine tunneling a ring, the operator of the assembly machine operates the assembly machine to assemble the single-layer lining segment to make the tunnel formed.

At present, China's largest shield terrestrial structure machine has a diameter of up to one meter.

On August 13, China's self-developed largest diameter slurry shield machine "Chunfeng" was officially put into use in Shenzhen Chunfeng Tunnel, and the construction of Chunfeng Tunnel will usher in a rapid construction stage. "Spring Breeze No. Head" is the largest diameter slurry shield independently developed in China, with a total length of 135 meters, a weight of more than 4,800 tons, and an excavation diameter of meters.

Jointly developed by China Railway Southern Investment Group, China Railway Tunnel Bureau, China Railway Equipment, State Key Laboratory of Shield and Tunneling Technology, it is a "big country heavy weapon" tailored for the construction of Chunfeng Tunnel, breaking through a series of key technologies, filling the gap in the field of large-diameter slurry balance shield machine with a diameter of 15 meters in China, marking that the development technology of China's large-diameter slurry balance shield machine has reached the world's leading level.

Shield elements

The subway shield construction method is mainly composed of three elements: stable excavation face, excavation and soil discharge, lining and grouting behind the wall. Among them, the stabilization method of the excavation face is the main aspect of its working principle, and it is also the main aspect that distinguishes it from the hard rock excavation method or is more complex than the hard rock excavation method. Most of the hard rock masses have good stability, and there is no problem of stability of the excavation face.

The tunnel construction with the subway shield method has the characteristics of high degree of automation, manpower saving, fast construction speed, one-time hole-making, not affected by climate, land settlement can be controlled during excavation, the impact on the ground building is reduced and the water surface traffic is not affected when the underwater excavation is carried out.

The world's largest excavation rig is a giant shield tunnel excavator called Bertha. This behemoth was born to be made for the purpose of digging tunnels, the manufacturing cost cost 500 million yuan, the overall length of the excavator is 110 meters, and the diameter has also reached meters, which was commissioned by the U.S. Transportation Agency to build the Japanese Hitachi Shipbuilding Company himself.

The digging speed of this big guy reached meters, the total weight was 7,000 tons, and the difficulties encountered in the transportation process after the completion of manufacturing can be imagined. In April of this year, the world's largest shield tunnel boring machine completed a major project to clear the mold shelter, that is, it took only four months to dig through the Seattle SR99 giant tunnel.

According to statistics, a total of 1,417 ring segments were installed on the entire Bertha excavator, and the total excavation length reached 2,825 meters. Of course, the internal working principle of the giant excavator is also very complex, and the rotator alone is equipped with up to 260 different types of alloy shield blades, which allows the excavator to move forward while digging, and the work efficiency is greatly improved.

The tail of the excavator is equipped with a pipe specially used to transport gravel, and a device for splicing concrete slabs is also installed, so that while the machine is digging in front, workers can install reinforcement plates in the rear synchronously, compressing several processes into one.

Hello dear <>

The largest diameter of the shield machine is 50 meters in diameter, and the "Juli No. 1" excavation diameter is 140 meters long and weighs 5,000 tons, which is the largest diameter shield machine in China, which can not only realize 5,000 meters of ultra-long-distance continuous tunneling without changing the tool, but also solve the world problem of "ten tunnels and nine leaks" under the super large diameter shield machine and high water pressure, and realize the tunnel tunneling construction without leakage, adding a sharp weapon to the construction of high water pressure and ultra-long-distance tunnel engineering in China. The shield machine is a type of tunnel boring machine that uses the trail shield method. The construction method of shield is the "shield" (referring to the supporting segment) of the tunnel constructed (laid) by the roadheader at the same time as the tunneling, which is different from the open construction method.

Internationally, generalized shield machines can also be used in rock formations, but they are different from open (non-shield) tunnel boring machines. In China, it is customary to call tunnel boring machines used in soft soil formations (narrow) shield machines, and those used in rock formations (narrow) TBM. I wish you a happy life!

Hope mine is helpful to you.

Summary. Parameters of the diameter meter shield machine.

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