Method for replacing shield cutter in sand-pebble layer

Abstract

The invention provides a method for replacing a shield cutter in a sand-pebble layer, which comprises the following steps: a, preparation steps before replacing the cutter are as follows: (1) selecting a position for replacing the cutter; (2) establishing a dewatering well to cause a shield cut position to completely be in the range of a drawdown curve; and (3) modifying soil mass in a soil storehouse, carrying out grouting on the upper part of a shield shell, pressing and injecting oil greases for a shield tail, dredging and washing grouting pipelines; b, steps for replacing the cutter are as follows: (1) carrying out dewatering construction and emptying the soil mass in the soil storehouse when the water level in the dewatering well reaches the required water level; and (2) installing a blanking plate in an empty position between the two pairs of cutter heads, rotating the cutter heads and performing replacement of the curter; and c, steps for recovering tunneling after replacing the cutter are as follows: (1) dismantling the blanking plate, closing the door of the soil storehouse and injecting inert serous fluid into the soil storehouse until soil pressure reaches the set soil pressure; and (2) recovering the tunneling. By utilizing the method, timely and effective replacement of worn cutters in the sand-pebble layer can be realized and the operation is relatively simple and safe.

Description

technical field [0001] The invention relates to a method for replacing a shield cutter, in particular to a method for replacing a shield cutter in a sandy pebble formation. Background technique [0002] The compound earth pressure balance shield machine is specially designed for tunnel construction for sand and pebble strata. It mainly uses the cutter on the cutter head panel to effectively cut and break the sand and pebble soil in front of the cutter head. Under the premise of soil improvement measures, a good entry and discharge channel is formed inside the shield machine, so that the shield tunnel can move forward smoothly, and can effectively reduce ground subsidence and its impact on the surrounding environment. [0003] At present, the cutters configured on the compound earth pressure balance shield machine mainly have the following forms, and the corresponding functions are shown in Table 1: [0004] [0005] [0006] The above shield cutting tools are all base...

AI Technical Summary

Problems solved by technology

[0007] (1) After the tool is worn, it cannot effectively cut the soil and break the rock, and the soil cannot enter the soil bin smoothly

[0008] (2) After the local tool is worn, the corresponding cutting and crushing loads of other tools increase, which accelerates the wear of other tools

[0009] (3) Increase the burden on the cutter head. After the contact between the cutter, the cutter head and the soil changes from the original line contact to the surface contact, the friction coefficient increases, and the cutter head torque needs to be increased accordingly to adapt to the increase in frictional resistance, resulting in The current consumption and oil pressure load increase, the frequency of mechanical failures is high, and the life of mechanical equipment is shortened

[0010] (4) After the tool protecting the cutterhead is worn out, the cutterhead directly contacts with high-strength pebbles, causing the cutterhead to wear out, affecting the mechanical equipment inside and behind the cutterhead panel to be directly damaged

[0011] (5) After the tool is partially worn, the cutting and crushing of the soil are hindered, which may easily cause over-excavation of the soil during the excavation process, cause ground subsidence, and endanger the surrounding environment

[0014] (1) Due to the uneven soil quality, the air pressure in the soil bin cannot be maintained, and it is difficult to provide the pressure maintaining state required for tool change

[0015] (2) Pneumatic tool change requires a large amount of air supply, long compressed air delivery pipelines, and high requirements for construction period equipment and air supply pipelines

[0016] (3) Tool replacement needs to turn the cutter head to a favorable position for tool change. During the process, pressure reduction is likely to occur, which endangers the stability of the excavation surface, easily causes ground subsidence and subsidence, and affects the surrounding environment along the tunnel

[0017] (4) Pneumatic tool change requires high personnel

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