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When the crane puts the shield machine into the working shaft and completes the installation, it can start to work
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When it comes to shield machines, many people may not know about it
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Under the joint action of the cutter head and the water spray, the lower portal collapses bit by bit
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Because it is not easy to replace the cutter head, the price is also expensive
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At the same time, the engineers will determine the size and orientation of the excavated portal in the reserved working shaft
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But when it comes to the subway tunnel, I believe you are all familiar with it
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In fact, the subway tunnel was dug out with this big guy
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If there is too much muck and earthwork, they will need the help of small excavators and drills
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Then, the workers will clean up the broken soil and reinforcement at the bottom of the hole
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Update the recruitment information of national tunnel and Bridge Engineering every day, including (tunnel excavation, support, second lining, pavement, greening, piling, beam erection, various special operators, drivers, and other engineering posts), trade new and old mechanical equipment, including (excavator, loader, mixer, tank car, bulldozer, roller and other equipment)
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Generally, shield machines are not used
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As for the train tunnel, the mountain is full of hard ore, and the tunnel length is relatively short
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In order to ensure the accuracy of the entrance and exit directions and the shield strength, many observation holes need to be opened on the concrete of the portal when it is close to the portal
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Some people are curious
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How does the shield machine get into and out of the tunnel? Usually, before the shield machine enters or leaves the tunnel, the workers will reserve the working shaft at two platforms and reinforce it with concrete walls for the assembly and disassembly of the shield machine
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However, the price of shield machine is very expensive
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The shield machine moves forward with the help of the jack, and the hydraulic motor drives the front cutter head to rotate continuously
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In addition to the high maintenance costs, shield machines are usually used for projects with long soft soil routes
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It has to be said that the shield machine can complete the tunnel at one time, which not only saves manpower, but also speeds up the progress
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In the rear, workers will assemble precast concrete pipes in the tunnel to form a tunnel structure
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The imported one is nearly 80 million US dollars, and the domestic one is more than 30 million US dollars
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