Earth pressure balance shield mud cake prevention system based on synchronous jet flow

Abstract

The invention provides an earth pressure balance shield mud cake prevention system based on synchronous jet flow. The system comprises a panel fixed sprayer, a cutterhead, a shield body, a soil warehouse separating plate, flushing guns, a flushing position location and tube connection, a high pressure pipeline and pipes, a water separator, a safety valve, a pressure gauge, a high pressure newly increased centrifugal pump, an original centrifugal pump, a base, a water supply pipe, a screw conveyor, a controller and a second trolley. The system provided by the invention has the advantages that working efficiency is high, cost is low, equipment investment is low, operation is simple, no dead angle flushing is carried out on the back of the cutterhead, a bracket of the cutterhead and the soil warehouse separating plate by virtue of the flushing guns at different positions of the soil warehouse separating plate, nozzles of the flushing guns are designed into different specifications, and axial four-hole, axial one-hole and radial four-hole structures are contained, so as to meet flushing requirements of different parts; no dead angle flushing is carried out on a cutter at the center part of the cutterhead by virtue of the panel fixed sprayer of the cutterhead; and mud cake flushing and shield tunneling are synchronous, and mud cake prevention does not influence normal shield tunneling.

Description

technical field [0001] The invention relates to an earth pressure balance shield mud cake prevention technology, in particular to a synchronous jet-based earth pressure balance shield mud cake prevention system, which belongs to the fluid control technology. Background technique [0002] The earth pressure balance shield uses the cutter head to cut the front soil, so that the soil enters the soil bin behind the cutter head in the form of dregs. By adjusting the relevant excavation parameters such as thrust, torque, and excavation volume, the soil inside the bin is achieved. The balance between water and soil pressure and the excavation surface, so as to control the surface settlement. When shield tunneling in argillaceous siltstone, because the soil is rich in clay minerals, the particle size is small and viscous, it is easy to attach to the cutterhead during the shield tunneling process. Afterwards, it is very easy to gradually spread from the center of the cutterhead ...

AI Technical Summary

Problems solved by technology

When shield tunneling in argillaceous siltstone, because the soil is rich in clay minerals, the particle size is small and viscous, it is easy to attach to the cutterhead during the shield tunneling process. Afterwards, it is very easy to gradually spread from the center of the cutterhead to the surroundings, forming an attached mud cake on the back of the cutterhead and the slag inlet; it will continue to thicken and harden under the action of higher soil temperature and pressure, and eventually lead to The slag inlet is covered with slag, and the cutter head loses the ability to cut the soil; the formation of mud cake in the soil bin is mainly due to uneven mixing of the slag, poor excavation parameters lead to slow replacement of the slag, and excessive synchronous grouting pressure causes mortar to enter Poor improvement of the soil silo and slag leads to poor excavation of the screw machine, so that the slag accumulates in the soil silo and produces mud cake

[0003] When the shield tunnels in upper soft and lower hard strata or full-section mudstone, mud cakes are easily produced on the cutter head and soil bins. At the same time, the difficulty of excavation and the increase of equipment failures caused by mud cakes will especially increase the damage of the main drive seal and unnecessary A series of risks such as opening positions under pressure

[0004] In order to solve the disadvantages of having to stop the machine when using conventional methods for mud cake treatment, and to avoid a series of risks caused by mud cakes, such as tunneling difficulties, equipment failures, especially damage to the main drive seal, and unnecessary opening of the warehouse under pressure, the mud cake prevention and control method commonly used Methods include muck improvement and adjustment of tunneling parameters. In the prior art, an appropriate amount of soil modifier is added to improve the workability of the soil and reduce the adhesion between the cutting soil and the shield machine cutterhead and structure. , and by setting reasonable tunneling parameters to ensure the stability of the earth pressure in the soil chamber and the smooth excavation, the shield tunneling will be "continuous, fast and stable", which will reduce the probability of mud cake formation in the cutterhead and soil chamber, However, the formation of mud cake cannot be completely avoided. Once a mud cake is formed, the tunneling can only be stopped, and the reserved hole is flushed or the warehouse is opened under pressure.

However, in the original design of the shield machine, the reserved holes at the partition did not consider mud cake flushing, and did not have the function of direct water spraying. The reserved holes were used to open and check the condition of the soil bin during open tunneling in hard rock formations. , or add additive injection channels according to needs in different strata, and during the earth pressure balance excavation period, the soil chamber is full of muddy water, once opened, it will cause the soil chamber to release pressure, and if it is not closed in time, it will cause a safety accident

Therefore, the conventional mud cake prevention method has low reliability, high risk, high cost, and affects the construction period

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