Cutter head cleaning method, tunnel construction method, cutter head cleaning device, and tunnel construction system

Abstract

To efficiently and safely remove deposits from cutter heads used in shield tunneling and pipe jacking methods. [Solution] A cleaning method according to one embodiment is for cleaning a cutterhead provided on a tunnel boring machine that excavates the ground to form a tunnel shaft, and includes a first step of placing a cleaning device inside the tunnel shaft, the cleaning device including a rod having a flow path formed therein, a monitor attached to the tip of the rod and spraying cleaning liquid supplied through the flow path, and a working machine that translates and rotates the rod; a second step of translating the rod with the working machine, causing the monitor to protrude from the front surface of the cutterhead through an opening in the cutterhead; and a third step of rotating the rod with the working machine while the monitor is protruding from the front surface, and spraying cleaning liquid from the monitor towards the front surface, thereby cleaning any deposits on the front surface.

Description

[Technical field]

[0001] The present invention relates to a method for cleaning a cutterhead used in a shield tunneling method or a jacking method, a tunnel construction method using said cleaning method, a cutterhead cleaning device, and a tunnel construction system using said cleaning device. [Background technology]

[0002] Known methods for forming tunnels underground include the shield method and the jacking method (see, for example, Patent Documents 1 and 2). In the shield method, segments that form the tunnel inner wall are assembled behind a tunnel boring machine (shield machine) that excavates the ground, and thrust is applied to the tunnel boring machine by a jack using the segments as fulcrums. In the jacking method, a pipe buried in the ground is pushed by a jack placed at the construction start point (shaft), and thrust is applied to the tunnel boring machine placed at the end of the pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-139320 A [Patent Document 2] JP 2024-101915 A Summary of the Invention [Problem to be solved by the invention]

[0004] In these shield and tunnel jacking methods, as the tunnel boring machine proceeds with excavation, gravel, clay, etc. may adhere to the cutter head and harden, causing the cutter head to rotate poorly or causing the opening (soil intake) of the cutter head to become clogged.

[0005] In such a case, a method for removing the deposits from the cutter head would be to move the tunnel boring machine back and have workers manually remove the deposits, but this requires measures such as supporting the ground in front of the cutter head, which requires a lot of time and effort, and is problematic from the standpoint of safety.

[0006] The present invention has been made in light of the above-mentioned circumstances, and one of its objects is to efficiently and safely remove deposits from cutter heads used in shield tunneling and jacking tunneling. [Means for solving the problem]

[0007] A cleaning method according to an embodiment of the present invention includes excavating ground to form a tunnel. The cutter head has a partition wall facing the rear surface of the cutter head, and a chamber between the cutter head and the partition wall. The cutter head has a soil intake port for taking soil generated by excavating the ground into the chamber. Tunnel Boring Machine The above A cutter head cleaning device includes a rod having a flow passage formed therein, and a cleaning liquid provided at the tip of the rod through the flow passage. Fold back at an angle greater than 90° A cleaning device including a monitor for spraying and a working machine for linearly moving and rotating the rod. , rear of the partition wall in the excavation direction of the tunnel boring machine and a first step of arranging the monitor in the work machine by linearly moving the rod. A valve provided in the partition; and The cutter head has The above mentioned soil intake Through The above A second step of projecting the monitor from a front surface of the cutter head in a direction of excavation; and the valve is closed around the rod. and a third step of rotating the rod by the work machine while spraying the cleaning liquid from the monitor toward the front surface in this state, thereby cleaning any deposits on the front surface.

[0008] A method for constructing a tunnel according to an embodiment includes the steps of: The present invention comprises a cutter head for excavating the ground to form a tunnel, a partition wall facing the rear surface of the cutter head, and a chamber between the cutter head and the partition wall, and the cutter head has a soil intake port for taking soil generated by excavating the ground into the chamber. Tunnel Boring Machine By The method includes excavating the ground, and cleaning the front surface of the cutter head in the direction of excavation of the tunnel boring machine by the above-mentioned cleaning method while the cutter head is stopped.

[0009] The cleaning device according to one embodiment excavates ground to form a tunnel. The cutter head has a partition wall facing the rear surface of the cutter head, and a chamber between the cutter head and the partition wall. The cutter head has a soil intake port for taking soil generated by excavating the ground into the chamber. Tunnel Boring Machine The above A cutter head cleaning device comprising: a rod having a flow passage formed therein; a cleaning liquid provided at the tip of the rod and supplied through the flow passage; Spray at an angle greater than 90° A monitor and The rear of the partition in the direction of tunnel excavation by the tunnel boring machine and a working machine arranged on the monitor for linearly moving and rotating the rod. Further, the cleaning device includes a monitor for linearly moving the rod by the working machine. A valve provided in the partition; and The cutter head has The soil intake port Throughout, The above The cutter head is projected from a front surface thereof in a direction of excavation, and the monitor is projected from the front surface thereof. and the valve is closed around the rod. In this state, the rod is rotated by the working machine, and the cleaning liquid is sprayed from the monitor toward the front surface, thereby cleaning off any deposits on the front surface.

[0010] A tunnel construction system according to an embodiment includes: The present invention comprises a cutter head for excavating the ground to form a tunnel, a partition wall facing the rear surface of the cutter head, and a chamber between the cutter head and the partition wall, and the cutter head has a soil intake port for taking soil generated by excavating the ground into the chamber. The system includes a tunnel boring machine and the above-mentioned cleaning device. Effect of the Invention

[0011] For example, according to the present invention, deposits on a cutter head used in a shield tunneling method or a jacking method can be efficiently and safely removed. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a tunnel construction system according to an embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an example of the structure of the rod and the monitor. [Diagram 3] FIG. 3 is a diagram showing an example of a configuration that can be applied to the cutter head. [Figure 4] FIG. 4 is a diagram showing another example of a configuration that can be applied to the cutter head. [Figure 5A]FIG. 5A illustrates an example of a method for constructing a tunnel and cleaning a cutter head according to one embodiment. [Figure 5B] FIG. 5B is a diagram showing a step subsequent to FIG. 5A. [Figure 5C] FIG. 5C is a diagram showing a step subsequent to FIG. 5B. [Figure 5D] FIG. 5D is a diagram showing a step subsequent to FIG. 5C. [Figure 5E] FIG. 5E is a diagram showing a step subsequent to FIG. 5D. [Figure 5F] FIG. 5F shows a step subsequent to FIG. 5E. [Figure 5G] FIG. 5G shows a step subsequent to FIG. 5F. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment will be described with reference to the drawings. In this embodiment, a cutter head cleaning method, a tunnel construction method, a cutter head cleaning device, and a tunnel construction system are disclosed, which are assumed to be used in the case of constructing a tunnel using a mud pressure shield method. In the mud pressure shield method, an additive for fluidizing the excavated soil is injected into a chamber behind the cutter head, thereby maintaining an appropriate pressure in the chamber and stabilizing the face.

[0014] However, the configuration disclosed in this embodiment, particularly the configuration related to the washing of the cutter head, can also be applied to other types of construction methods that use cutter heads to build tunnels. Examples of such other types of construction methods include a muddy water shield method. In a muddy water shield method, the excavated soil is separated into soil and muddy water by a muddy water treatment facility outside the tunnel, and the muddy water is sent to a chamber behind the cutter head, and the pressure in the chamber is appropriately maintained to stabilize the face. In addition, the configuration related to the washing of the cutter head disclosed in this embodiment can be applied not only to the shield method, but also to various types of jacking methods such as mud pressure type and muddy water type.

[0015] 1 is a diagram showing a schematic configuration of a tunnel construction system 1 according to this embodiment. The elements shown in this diagram are only a part of the tunnel construction system 1, and the tunnel construction system 1 may also include various other devices or equipment.

[0016] The tunnel construction system 1 includes a tunnel boring machine 2 that excavates the ground G to form a tunnel hole T. In the following description, the direction in which the tunnel boring machine 2 proceeds while excavating the ground G (the extension direction of the tunnel hole T) is referred to as the excavation direction D1.

[0017] The tunnel boring machine 2 includes a cutter head 3 and a partition wall 4. The cutter head 3 and the partition wall 4 are circular in a front view. A large number of cutter bits 31 are provided on a front surface 30 of the cutter head 3 in the excavation direction D1. The cutter head 3 also has a plurality of openings 32. The cutter head 3 is rotationally driven by a drive unit 34 to excavate the ground G.

[0018] The partition wall 4 is located behind the cutter head 3 in the excavation direction D1 and faces the back surface of the cutter head 3. A chamber C is formed between the cutter head 3 and the partition wall 4. When the ground G is excavated with the rotation of the cutter head 3, the soil is taken into the chamber C through the opening 32. That is, the opening 32 functions as a soil intake port.

[0019] The partition wall 4 is provided with a pressure gauge 41 for detecting the pressure in the chamber C, and at least one valve 42. In this embodiment, it is assumed that a plurality of valves 42 are arranged in the radial direction of the partition wall 4.

[0020] A large number of curved segments S are fitted into the inner surface of the tunnel hole T created by excavation by the tunnel boring machine 2. The segments S are attached by an erector (not shown) to the inner surface of the tunnel hole T newly created as the tunnel boring machine 2 advances.

[0021] A plurality of jacks 5 are disposed between the existing segments S and the tunnel boring machine 2. These jacks 5 receive a reaction force from the existing segments S and provide the tunnel boring machine 2 with a propulsive force in the excavation direction D1.

[0022] The tunnel construction system 1 further includes an additive supplying device 6 that supplies additive to the tunnel boring machine 2, and an earth removal device 7 that discharges soil from the chamber C. The additive is mixed with the soil excavated by the cutter head 3 to impart plastic fluidity to the soil and turn it into mud, and for example, a mud-adding material or an aerated material can be used. The additive supplying device 6 includes, for example, an additive storage section and a pump. The additive supplying device 6 may be located on the ground, or at least a part of it may be located inside the tunnel hole T.

[0023] The soil discharge device 7 is equipped with a screw conveyor that leads to the chamber C through an opening provided in the partition wall 4, for example. The soil M discharged from the chamber C by this screw conveyor is transported by a belt conveyor or a transport vehicle toward the entrance of the tunnel T, and is transported to the ground by a crane or the like in the vertical shaft at the entrance.

[0024] The additive supplied from the additive supply device 6 is sent to the chamber C via the supply pipe 61 and mixed with the soil and sand taken into the chamber C through the opening 32. By appropriately maintaining the mud pressure (mud pressure) generated by this mixing, it is possible to stabilize the face facing the cutter head 3.

[0025] The mud pressure data of chamber C measured by the pressure gauge 41 is output to the control device 100. For example, the control device 100 controls the additive supply device 6 and the soil discharge device 7 based on the mud pressure data of chamber C, and adjusts the supply amount of additive and the amount of soil discharged from chamber C so that the mud pressure of chamber C remains within an appropriate range. Such adjustments may be made by an operator checking the mud pressure data and manually changing the control conditions of the additive supply device 6 and the soil discharge device 7.

[0026] In this embodiment, the tunnel construction system 1 further includes a cleaning device 8 for the cutter head 3. The cleaning device 8 includes a working machine 81, a rod 82, and a monitor 83.

[0027] The work machine 81 includes a linear motion mechanism that linearly moves the rod 82 in the direction in which it extends, and a rotation mechanism that rotates the rod 82. The rod 82 is made of, for example, a hollow metal. A cleaning liquid supply pipe 91 is attached to the rear end of the rod 82. The monitor 83 is attached to the tip of the rod 82. The rod 82 and the monitor 83 can be inserted into the valve 42 provided in the partition 4 and the opening 32 of the cutter head 3.

[0028] A cleaning liquid is supplied to the supply pipe 91 by a cleaning liquid supply device 9. For example, muddy water can be used as the cleaning liquid, but the example is not limited thereto. The cleaning liquid supply device 9 has, for example, a cleaning liquid storage section and a pump. The cleaning liquid supply device 9 may be disposed on the ground, or at least a part of it may be disposed inside the tunnel T. The cleaning liquid supplied from the cleaning liquid supply device 9 to the rod 82 via the supply pipe 91 is sent to the monitor 83 through the inside of the rod 82 and sprayed from the monitor 83.

[0029] 2 is a schematic cross-sectional view showing an example of the structure of the rod 82 and the monitor 83. A flow path 820 for the cleaning liquid is provided inside the rod 82. A flow path 830 for the cleaning liquid is provided inside the monitor 83. A nozzle 831 for spraying the cleaning liquid is provided at the end of the flow path 830. In addition, an excavation bit 832 capable of excavating the ground G is provided at the tip of the monitor 83.

[0030] The cleaning liquid supplied to the rod 82 flows in a supply direction D2 in the flow path 820. When the rod 82 is parallel to the excavation direction D1, the supply direction D2 is also parallel to the excavation direction D1.

[0031] For example, the nozzle 831 is directed backward (upstream) in the supply direction D2. That is, the spray direction J of the cleaning liquid from the nozzle 831 is inclined at an angle θ greater than 90° with respect to the supply direction D2 (90°<θ). In one example, the angle θ is 120° or more and 180° or less (120°≦θ≦180°). The flow path 830 is bent at least once before reaching the nozzle 831.

[0032] 3 and 4 are diagrams showing an example of a configuration applicable to the cutter head 3. These diagrams correspond to front views of the cutter head 3 as viewed from the front surface 30 side.

[0033] The cutter head 3 shown in Fig. 3 corresponds to a so-called spoke type configuration, and includes an outer ring body 35 at the outermost periphery and a plurality of spokes 36 extending radially inside the outer ring body 35. The cutter bit 31 is provided on, for example, the spokes 36. Furthermore, in the example of Fig. 3, a support member 37 is disposed between the outer ring body 35 and the center of the cutter head 3.

[0034] In this configuration, a plurality of openings 32 are formed, each surrounded by the outer annular body 35, the spokes 36, and the support member 37. These openings 32 are aligned in the circumferential and radial directions of the cutter head 3.

[0035] The cutter head 3 shown in Fig. 4 corresponds to a so-called face plate type configuration, and a large part of it is formed by a face plate member 38. In such face plate member 38, a plurality of openings 32 extending in the radial direction are formed. These openings 32 are aligned in the circumferential direction of the cutter head 3. The cutter bits 31 are arranged on the edges of the openings 32, etc.

[0036] In addition to the above, various configurations can be applied to the cutter head 3. In other words, the form of the opening 32 as the soil intake port is not particularly limited. As another example, the cutter head 3 may have a lattice-shaped opening 32.

[0037] 5A to 5F are diagrams showing an example of a tunnel constructing method and a method of cleaning the cutter head 3 according to this embodiment.

[0038] As explained with reference to Figure 1, when forming the tunnel hole T, the jack 5 applies a thrust to the tunnel boring machine 2 in the excavation direction D1, and the cutter head 3 rotates. This causes the ground G to be excavated. The soil generated by the excavation of the ground G is taken into the chamber C through the opening 32. Also, the amount of additive supplied from the supply pipe 61 and the amount of soil discharged by the soil discharge device 7 are adjusted so that the mud pressure in the chamber C is within an appropriate range.

[0039] In the process of excavating the ground G in this way, gravel, clay, etc. adhere to the cutter head 3. When such deposits X accumulate, at least a part of the multiple openings 32 may be blocked as shown in Fig. 5A, which may hinder the intake of soil and sand into the chamber C and reduce the mud pressure applied to the face. In addition, the deposits X may cause the cutter head 3 to have trouble rotating.

[0040] In this embodiment, when it is necessary to remove such deposits X, the cutter head 3 is washed using a washing device 8 while the rotation of the cutter head 3 is stopped. For this washing, first, as shown in Fig. 5B, the washing device 8 is placed in the tunnel hole T near the tunnel boring machine 2 (first step).

[0041] Furthermore, the rod 82, the valve 42, and the opening 32 are positioned so as to be aligned in the excavation direction D1. In one example, the cleaning device 8 is disposed so that the rod 82 faces one of the valves 42, and the cutter head 3 is rotated so that the valve 42 and one of the openings 32 face the excavation direction D1. The attitude of the cutter head 3 (rotation angle from the reference state) can be confirmed by displaying information representing the attitude on the display of the control device 100, for example, based on the output of a sensor provided in the tunnel boring machine 2. Therefore, the operator can position the rod 82, the valve 42, and the opening 32 without releasing the sealed state of the chamber C. The positioning of the valve 42 and one of the openings 32 may be automatically performed by the control device 100.

[0042] Next, as shown in Fig. 5C, the rod 82 is linearly moved by the work machine 81, causing the monitor 83 to protrude from the front surface 30 of the cutter head 3 through the opening 32 (second step). In this operation, the rod 82 and the monitor 83 are sent to the cutter head 3 through the valve 42. After the linear movement stops, the valve 42 is closed to close the periphery of the rod 82.

[0043] When protruding the monitor 83 from the front face 30, the face of the ground G facing the front face 30 may be excavated by the monitor 83. In this case, the rod 82 is rotated when the rod 82 is moved linearly by the work machine 81. This allows the excavation face to be excavated by the drilling bit 832 at the tip of the monitor 83, and the monitor 83 can be protruded from the front face 30 by an appropriate protruding length.

[0044] After the monitor 83 is protruded from the front surface 30, as shown in Fig. 5D, the rod 82 and the monitor 83 are rotated by the work machine 81, and the cleaning liquid is sprayed from the monitor 83 toward the front surface 30 (third step). As a result, the deposits X on the front surface 30 are cleaned within the spray range of the cleaning liquid.

[0045] When cleaning is completed, as shown in Fig. 5E, the work machine 81 retracts the rod 82 and the monitor 83. Furthermore, the cutter head 3 is rotated to face the other opening 32 and the valve 42. In this state, as shown in Fig. 5F, the rod 82 is inserted into the valve 42 and the opening 32 to cause the monitor 83 to protrude from the front surface 30, and the cleaning liquid is sprayed while the monitor 83 is rotated to clean the front surface 30.

[0046] 5C to 5F, cleaning can be performed for each of the openings 32 arranged in the circumferential direction at the radial position of the upper valve 42 in the figure. Also, by using the lower valve 42 in the figure as an insertion port for the rod 82 and the monitor 83, cleaning can be performed for the more outer circumferential region of the front surface 30 of the cutter head 3. In this way, as shown in FIG. 5G, the front surface 30 can be entirely cleaned and the deposits X can be removed.

[0047] Although the example described here is one in which two valves 42 are provided on the partition wall 4, more valves 42 may be provided on the partition wall 4 by changing the radial position. This allows the front surface 30 to be cleaned over a wider range.

[0048] The pressure of the cleaning liquid required for cleaning may vary depending on the properties of the deposit X, the type of cleaning liquid, the configuration of the cutter head 3, and further the configuration of the monitor 83. As an example, spraying the cleaning liquid at a pressure of 20 MPa or more, preferably 30 MPa or more, can satisfactorily remove the deposit X. However, the cleaning liquid may be sprayed at a lower pressure to remove the deposit X over a longer period of time.

[0049] From the viewpoint of stabilizing the face, it is preferable that the mud pressure in chamber C during cleaning is also within the above-mentioned appropriate range. Therefore, the mud pressure measured by the pressure gauge 41 may be monitored during cleaning, and at least one of the soil removal device 7 and the cleaning device 8 may be controlled so that the value remains within the appropriate range.

[0050] For example, when the mud pressure exceeds an appropriate range, the pressure in the chamber C can be reduced by discharging the mud or muddy water in the chamber C using the soil discharge device 7.

[0051] It is also possible to suppress the rise in mud pressure by lowering the spray pressure of the cleaning liquid from the monitor 83 or by stopping the spray. Such control may be performed by the control device 100, or may be performed by an operator checking the mud pressure data and manually changing the control conditions of the soil removal device 7 and the cleaning device 8.

[0052] In the present embodiment described above, the deposits X on the cutter head 3 can be removed by the cleaning device 8 without retracting the tunnel boring machine 2. In this case, cleaning can be performed with the tunnel boring machine 2 in a stable state, so there is no need for the support measures for the face that are required when retracting the tunnel boring machine 2 as described above. This makes it possible to significantly improve the cost and efficiency of cleaning. In addition, safety is also extremely high, as there is no need for workers to go out in front of the tunnel boring machine 2.

[0053] In this embodiment, the opening 32 provided in the cutter head 3 as a soil intake port is used as a passage for the monitor 83. This makes it unnecessary to perform any special processing on the cutter head 3 when cleaning. Furthermore, during cleaning, the valve 42 provided in the bulkhead 4 closes the area around the rod 82, thereby preventing leakage of muddy water from the chamber C. In addition to the above-mentioned examples, various other advantageous effects can be obtained from this embodiment.

[0054] The scope of the present invention is not limited to the configurations disclosed in the above-mentioned embodiments. In addition, the cutter head cleaning method, tunnel construction method, cutter head cleaning device, and tunnel construction system can be realized in various other forms without departing from the spirit of the present invention. [Explanation of symbols]

[0055] 1...tunnel construction system, 2...tunnel boring machine, 3...cutter head, 4...partition wall, 5...jack, 6...additive supply device, 7...soil removal device, 8...cleaning device, 9...cleaning liquid supply device, 30...front, 31...cutter bit, 32...opening, 41...pressure gauge, 42...valve, 81...work machine, 82...rod, 83...monitor, D1...excavation direction, G...ground, J...spray direction, X...deposits.

Claims

1. A method for cleaning a cutterhead of a tunnel boring machine, the cutterhead comprising: a cutterhead for excavating the ground to form a tunnel; a partition wall facing a rear surface of the cutterhead; and a chamber between the cutterhead and the partition wall, the cutterhead having a soil intake port for taking soil generated by excavating the ground into the chamber, the method comprising the steps of: a first step of disposing a cleaning device including a rod having a flow path formed therein, a monitor provided at the tip of the rod for turning back and spraying the cleaning liquid supplied through the flow path at an angle greater than 90°, and a working machine for linearly moving and rotating the rod, behind the partition wall in the excavation direction of the tunnel boring machine; A second step of causing the monitor to protrude from a front surface of the cutter head in the excavation direction through a valve provided in the partition and the soil intake port of the cutter head by linearly moving the rod with the working machine; a third step of rotating the rod by the work machine while spraying the cleaning liquid from the monitor toward the front surface in a state in which the monitor protrudes from the front surface and the periphery of the rod is closed by the valve, thereby cleaning deposits on the front surface; A cleaning method comprising:

2. The cutter head has a plurality of soil intake openings into which the rod and the monitor can be inserted, The second step and the third step are carried out for each of the plurality of soil intake ports. The cleaning method according to claim 1 .

3. In the third step, at least one of a soil discharge device that discharges the mud accumulated in the chamber and the cleaning device is controlled so that the mud pressure in the chamber during cleaning remains within a predetermined range. The cleaning method according to claim 1 .

4. The ground is excavated by a tunnel boring machine comprising a cutterhead for excavating the ground to form a tunnel, a partition wall facing the back surface of the cutterhead, and a chamber between the cutterhead and the partition wall, the cutterhead having a soil intake port for taking soil generated by excavating the ground into the chamber, While the cutter head is stopped, a front surface of the cutter head in the excavation direction of the tunnel boring machine is cleaned by the cleaning method according to any one of claims 1 to 3. A tunnel construction method comprising:

5. A cleaning device for a cutterhead of a tunnel boring machine, comprising: a cutterhead for excavating the ground to form a tunnel hole; a partition wall facing a rear surface of the cutterhead; and a chamber between the cutterhead and the partition wall, the cutterhead having a soil intake port for taking soil generated by excavating the ground into the chamber, A rod having a flow passage formed therein; a monitor provided at a tip of the rod for jetting the cleaning liquid supplied through the flow path at an angle greater than 90°; a working machine arranged behind the partition wall in the excavation direction of the tunnel boring machine, for translating and rotating the rod; Equipped with By linearly moving the rod by the working machine, the monitor is protruded from the front surface of the cutter head in the excavation direction through the valve provided in the partition and the soil intake port of the cutter head, With the monitor protruding from the front surface and the periphery of the rod being closed by the valve, the rod is rotated by the work machine and the cleaning liquid is sprayed from the monitor toward the front surface, thereby cleaning deposits on the front surface. Cleaning equipment.

6. A tunnel boring machine comprising: a cutterhead for excavating the ground to form a tunnel; a partition wall facing the back surface of the cutterhead; and a chamber between the cutterhead and the partition wall, the cutterhead having a soil intake port for taking soil generated by excavating the ground into the chamber; A cleaning device according to claim 5 ; A tunnel construction system comprising:

7. The cutter head has a plurality of soil intake openings into which the rod and the monitor can be inserted. A tunnel construction system according to claim 6.

8. A pressure gauge for detecting the mud pressure in the chamber; A soil discharge device that discharges mud accumulated in the chamber; A control device that controls at least one of the soil removal device and the cleaning device so that the mud pressure in the chamber during cleaning remains within a predetermined range; 8. A tunnel construction system according to claim 6 or 7, further comprising:

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