Slurry shield tail brush replacement liquid nitrogen freezing safety protection device and method under high water pressure condition

Abstract

The invention relates to a slurry shield tail brush replacement liquid nitrogen freezing safety protection device under a high water pressure condition. The device comprises a shield tail shell, a shield tail brush and a duct piece which are arranged from outside to inside; mortar pipes are arranged inside the shield tail shell; the device further comprises at least one set of liquid nitrogen freezing device; each liquid nitrogen freezing device is arranged inside the shield tail shell and located between the adjacent mortar pipes; and each liquid nitrogen freezing device comprises a liquid inlet pipe, a liquid outlet pipe and an annular freezing pipe, wherein the annular freezing pipe is connected between the other ends of the liquid inlet pipe and the liquid outlet pipe. The device has the beneficial effects that the risk of hole drilling in the duct piece and destructive influences on the structure of the duct piece are avoided, the annular liquid nitrogen freezing pipes are arranged at the shield tail and form a liquid nitrogen circulation channel with the liquid inlet pipes and the liquid outlet pipes which are reserved in the middle shield position, circular liquid nitrogen in the channel can rapidly freeze a soil body at the shield tail, impurities like slurry and mortar are prevented from entering a shield machine, the device is easy and convenient to operate, freezing is rapid, and personnel and equipment safety in the shield tail brush replacement process can be effectively ensured.

Description

technical field [0001] The invention relates to the field of shield machines, and more specifically relates to a safety protection device and method for replacing liquid nitrogen freezing safety protection devices and methods for shield tail brushes of muddy water shields under high water pressure conditions. Background technique [0002] The shield tail wire brush is an important part of the sealing system of the shield machine. In the construction of a large-diameter mud-water balance shield, the shield tail brush is used and a certain amount of filler (shield tail grease) is injected, which can be used on the shield machine and A good sealing system is formed between the segments, which can effectively prevent groundwater, mud and synchronous grouting slurry from flowing into the shield machine, ensuring safe and smooth tunneling. However, due to unavoidable construction errors during the construction process, the shield tail brush is over-extruded by the eccentric segmen...

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Problems solved by technology

[0004] ① The application number is 201210175808.4, a method for replacing the tail brush by freezing liquid nitrogen in a shield tunnel. This invention discloses a method for replacing the tail brush by freezing liquid nitrogen. After determining the position of the tail brush to be replaced, the method passes Twice drilling provides conditions for the freezing operation, which is time-consuming and laborious to operate, and the efficiency of freezing and sealing is low;

[0005] ②Application No. 201210068168.1 is the shield tail sealing device of the shield machine. This invention adds a sealing brush and a sealing plate on the basis of the conventional sealing device. Tail leakage cannot be effectively dealt with; on the other hand, although the present invention adds a sealing plate, there is a problem of poor adhesion between the sealing plate and the segment, which has a certain impact on its anti-seepage effect;

[0006] ③Application No. 201220102998.2 The shield tail emergency sealing device for shield machine and its installation structure, there are two problems in this patent: on the one hand, the inflatable rubber tube used in this patent exists in the shield tail grease for a long time, and after a long time After a while, the aging of the rubber tube will inevitably occur. Once it is aged, it is very likely to affect the airtightness of the emergency seal and affect the sealing effect; on the other hand, the patent uses an inflated rubber tube for emergency sealing. There are problems such as loose fit and water seepage between the rubber and the segment

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