JP5016415B2 - Muddy water shield machine and muddy water shield method - Google Patents

Description

  The present invention relates to a muddy water shield excavator and a muddy water shield method, and more particularly to a muddy water shield machine and a muddy water shield method capable of continuously excavating gravelly ground.

  As a method for constructing a tunnel structure in an underground space of a major urban area where population is remarkable, a muddy water shield method has been conventionally known. Thus, the conventional muddy water seal excavator and muddy water shield construction method will be described with reference to FIGS. It should be noted that the configuration described only in FIG. 6 and FIG. 7 and having been described with reference numerals and having only reference numerals is the part common to the embodiment of the present invention, so The code | symbol used for the example is attached | subjected and the description is abbreviate | omitted.

  FIG. 6 shows the time of excavation by a general muddy water shield excavator in the ground where the gravel diameter is not large or a small amount of gravel appears, and the chamber 14 and the classifier are provided without providing the gravel crusher as a single roll crusher. 20 and only the mud pipe 16 is provided. In this case, the cutter head 11 is rotated by a drive motor to excavate the face, mud is supplied from the mud pipe 15 to fill the chamber 14 with mud, and the excavated earth and sand is taken into the mud to discharge the mud. The drainage water is discharged through the intake port 32b on the end surface of the drainage pipe 16.

  FIG. 7 shows the time of excavation by a general mud shield excavator on the ground where large gravel appears, and the drainage between the chamber 14 and the classifier 20 is not provided without the gravel crusher as a secondary crusher. The mud pipe 16, the gravel collecting box 34 and the crusher 33 are provided as secondary crushers, and the gravel sent to the classifier 20 through the mud pipe 16 passes through the pump 23 by the crusher 33. It is crushed again into a gravel diameter that can be sized and discharged to the classifier 20 side.

In addition, the code | symbol 35 is a shield jack, the code | symbol 36 is a segment, and the code | symbol 21 is a pump for accelerating the flow velocity to the pump 23 of the mud drain water in the mud pipe 16. FIG.

  In the muddy water shield method where gravel appears, it is necessary to crush the gravel diameter to a diameter that can finally pass through the pump. Generally, as shown in FIG. Secondary crushing at. However, since the diameter of gravel passing through the cutter head is short, the mud pipe is blocked, the crusher in front of the pump is not likely to be swallowed, and the pump cannot be passed. The frequency of removal with a classifier is high. Patent Document 1 and Patent Document 2 disclose a method of reducing the frequency of removal with a gravel collecting box or a classifier.

Further, in Patent Document 1 and Patent Document 2, a mud pipe and a mud pipe are connected to a chamber provided behind the cutter head via a partition wall, and mud is sent into the chamber through the mud pipe. Is a facility that uses a mud shield method to excavate the ground by pumping mud drained water mixed with cutting earth and sand through the mud pipe to the ground. The technique of the muddy water shield excavation apparatus provided with the gravel removal means which crushes is disclosed.
JP2007-113213A. JP 2002-168091 A.

  The mud shield digging apparatus described in Patent Document 1 and Patent Document 2 is crushed by a rod that reciprocates the gravel blocking the drainage pipe inlet when the inlet of the drainage pipe is blocked by gravel. However, the amount of earth and sand taken in the sludge pipe inlet of this equipment is that the inlet is closed until the gravel of the inlet is crushed with a rod. Therefore, there is a problem in that it does not become constant and affects the excavation speed control and the pump operation control. Moreover, since it was not a planned crushing diameter, there existed a problem that the earth and sand containing this gravel could not be crushed systematically until it became a gravel diameter of the magnitude | size which can be pumped to the ground.

Therefore, in the muddy water shield digging method in the ground containing gravel, a certain amount of earth and sand containing gravel can be taken in without blocking the gravel intake of the partition wall, and the mud water containing the gravel is directed to the ground. As a result, there are technical problems that need to be solved in order to provide a mud shield machine with built-in crusher and a mud shield method that can crush gravel below the diameter of each grab pipe, gravel crusher, or pump. Therefore, an object of the present invention is to solve the problem.

The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is characterized in that a mud pipe and a mud pipe are connected to a chamber provided behind the cutter head via a partition wall, and the chamber is provided. sending mud through Okudoro tube within, the exhaust mud and cutting soil and該泥water is mixed with a mud shield machine for ground excavation and pumped to the ground via a waste sludge tube, into the chamber It has an intake port opened and a discharge port connected to the intake port of the mud pipe, and is disposed as a part of a passage for sending the mud water in the chamber into the mud pipe, A housing in which the inner diameter of the intake port is larger than the inner diameter of the mud pipe and gradually decreases toward the rear side, a fixed tooth attached to the inner peripheral surface of the housing, and the fixed tooth A rotating tooth rotatably disposed in the housing In the muddy water shield machine provided with a single roll crusher, the cutting earth and sand swallowed between the rotating teeth and the fixed teeth, with the rotating teeth rotating in the same direction as the cutter head rotating The mud shield shield machine is provided in which the gravel contained in is crushed into a gravel diameter smaller than the inner diameter of the drainage pipe and sent to the discharge port side .

According to this configuration, the single-roll crusher provided with the cone-shaped housing that gradually decreases toward the rear side in the passage for sending the sludge water in the chamber to the sludge pipe, the gravel taken into the housing is removed. Systematically crush the contained earth and sand. The earth and sand containing the crushed gravel is guided to a sludge pipe connected to the single roll crusher by natural fall and rotation of rotating teeth. In addition, the housing with a large intake port on the chamber side makes it easier to swallow gravel larger than the subsequent sludge pipe diameter. This large gravel is crushed by a single roll crusher, and the subsequent waste mud is planned. The gravel diameter can be made smaller than the pipe diameter. Furthermore, it is possible to set the gravel diameter to be equal to or smaller than the pump passage diameter for pumping to the ground. Further, since the rotation direction of the rotary teeth of the single roll crusher is set to the same direction as the rotation direction of the cutter head, the shaft for rotating the rotary teeth can be extended in the excavation direction.

  According to a second aspect of the present invention, there is provided a muddy water shield machine in which the discharge port of the housing and the mud pipe opened in the chamber are connected by a communication pipe.

  According to this configuration, large gravel is taken into the mud pipe through the single roll crusher by connecting the housing outlet to the inlet of the mud pipe leading to the chamber, and the mud is not passed through the single roll crusher. Reduce the amount of large gravel that goes directly to the pipe entrance. Further, when the drainage water flows through the drainage pipe, the discharge port of the single roll crusher becomes a negative pressure due to the flow rate of the drainage pipe, so that the gravel easily passes through the single roll crusher because it is drawn into the drainage pipe.

  According to a third aspect of the present invention, there is provided a muddy water shield machine in which the rotating surface of the rotating tooth rotates in a non-circular shape.

  According to this configuration, since the rotation of the rotating teeth is eccentric with respect to the housing, a swinging motion is added, and the gravel is easily crushed by being hit, and the crushed gravel is discharged toward the discharge port. It becomes easy.

  According to a fourth aspect of the present invention, there is provided a muddy water shield machine in which the single roll crusher and the mud pipe are configured to be detachable integrally with the partition wall.

  According to this configuration, the single roll crusher and the mud pipe can be integrally removed from the partition wall and replaced with another single roll crusher and a mud pipe.

The invention according to claim 5 connects the mud pipe and the mud pipe to the chamber provided behind the cutter head via a partition, and sends the mud water through the mud pipe into the chamber. In the muddy water shield construction method for excavating the ground by pumping the muddy water mixed with water to the ground through a muddy pipe, it is included in the muddy water using the muddy water shield machine according to claim 1, 2, 3 or 4. A muddy water shield method is provided in which the gravel is crushed into a gravel diameter that can be pumped by the single roll crusher according to claim 1, 2, 3, or 4 and pumped to the ground.

  According to this method, when the gravel is crushed to a gravel diameter that can be pumped to the ground by a single roll crusher provided immediately after the partition, the gravel is crushed between the partition and the ground. There is no need to provide a separate crushing device. Therefore, it is suitable for the ground with a low gravel rate and a small amount of gravel, or when there are some gravel sections.

The invention according to claim 6 connects a mud pipe and a mud pipe through a partition wall to a chamber provided behind the cutter head, and sends mud water through the mud pipe into the chamber. A muddy water shield method for excavating the ground by installing a gravel crushing device on the upstream side of a pump that pumps the mixed mud drainage water to the ground via a drainage pipe and crushing it into a gravel diameter that can pass through the pump Then, using the mud shield shield machine according to claim 1, 2, 3 or 4 , among the gravel passing through the gravel crushing device, the gravel having an outer diameter larger than the drainage pipe diameter is crushed by the single roll crusher. And mixed with the waste water containing small gravel with a small outer diameter taken directly into the waste pipe through the waste pipe, and then the gravel contained in the mixed waste water is Pump can be passed with gravel crusher before pump We provide a muddy water shield method that is crushed into gravel diameters and pumped to the ground.

  According to this method, there is a balance between single-roll crusher capacity and excavation speed, restrictions on the installation space, etc. in the case of ground with a lot of gravels and a high gravel rate, but there is a separate crushing device in front of the pump. By crushing the gravel after passing through the single roll crusher again with the crushing device, the single roll crusher can be reduced in size.

  In the first aspect of the present invention, large gravel is swallowed by a single roll crusher provided with an intake port having a diameter larger than the succeeding mud pipe diameter, and this is crushed to be smaller than the succeeding mud pipe diameter. Since it can be directed to the drainage pipe, the gravel can be taken up smoothly in the subsequent drainage pipe.

  Moreover, in a single roll crusher, if the gravel diameter to be crushed is set to be equal to or smaller than the pump passage diameter that is pumped to the ground, it is possible to reduce the equipment by eliminating the gravel crushing apparatus before passing through the pump. As a result, the installation space is not limited.

Furthermore, the crushing work efficiency is improved because the cobble can be continuously crushed by continuously rotating the rotating teeth of the single roll crusher. Furthermore, according to the present invention, since the rotating shaft for rotating the rotating teeth can be arranged to extend in the excavation direction, the equipment can be reduced in size or increased in size and easily adapted to the processing amount.

  According to the second aspect of the present invention, the crushed gravel can be smoothly discharged from the single roll crusher using the negative pressure generated in the single roll crusher acting from the mud pipe side. In addition to the effects of the described invention, workability can be improved.

  Furthermore, since the mud water containing gravel can be taken in at two places, the intake port opened in the chamber and the mud pipe opened in the chamber, the single roll crusher can be downsized. As a result, the installation space is not restricted, and workability can be improved in addition to the effect of the first aspect of the invention.

  According to the third aspect of the present invention, the gravel taken in the single roll crusher is smoothly taken in between the fixed teeth and the rotating teeth and crushed, and the crushed gravel is passed through the inlet of the mud pipe. Since it can discharge | emit toward an exit, in addition to the effect of the invention of Claim 1 or 2, workability | operativity can be improved further.

  In the invention according to claim 4, when the single roll crusher and the sludge pipe need to be detached due to a partial change in the construction method, maintenance inspection, etc., the single roll crusher and the sludge pipe are integrally detached and replaced. Alternatively, since the inspection work can be performed, in addition to the effect of the invention described in claim 1, 2 or 3, the range of use can be expanded and the maintenance inspection work can be improved.

According to the invention described in claim 5, since it is not necessary to separately provide a crushing device for crushing gravel between the partition wall and the ground, the facility can be downsized. In addition, the single roll crusher in the partition wall can be reduced in size, and the installation space of the facility is less restricted. In particular, it is suitable when working on ground with a low gravel rate and less gravels, or when working on ground with some gravel sections.

The invention according to claim 6 can reduce the size of the single roll crusher in the partition wall portion, so that the installation space of the facility is less restricted.

The present invention is a muddy water shielding method for ground containing gravel, which can take in a certain amount of earth and sand containing gravel without blocking the gravel intake of the partition wall, and directs the mud water containing the gravel to the ground. In order to achieve the purpose of providing a mud shield machine and a mud shield method, it is possible to provide a mud shield machine and a mud shield method with a built-in crusher capable of crushing gravel below the pebbles that can pass through A mud pipe and a waste mud pipe are connected to a chamber provided at the rear via a partition wall, mud water is sent into the chamber through the mud pipe, and the mud water mixed with the mud water and the cut soil is discharged. A muddy water shield machine for excavating the ground by pumping to the ground , and having an intake port opened in the chamber and an exhaust port connected to the intake port of the mud pipe In front of the waste water A housing that is disposed as a part of a passage that feeds into the mud drain pipe, and has an inner diameter that is larger than the inner diameter of the mud pipe and gradually decreases toward the rear side; A muddy water shield excavator provided with a single roll crusher comprising a fixed tooth attached to an inner peripheral surface and a rotating tooth rotatably disposed in the housing so as to face the fixed tooth. The rotation direction of the cutter head is set to the same direction as the rotation direction of the cutter head, and the gravel contained in the cutting soil swallowed between the rotating teeth and the fixed teeth is at least smaller than the inner diameter of the drainage pipe This was realized by crushed to a diameter and sent to the outlet side .

  Hereinafter, the muddy water shield construction method of the present invention will be described with a preferred embodiment together with a muddy water shield machine.

  1 is a schematic cross-sectional view of the entire muddy water shield machine that implements the muddy water shield method of the present invention, FIG. 2 is an enlarged cross-sectional view of the main part of the muddy water shield machine, and FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 and FIG. 4 are enlarged sectional views taken along line BB in FIG.

  1 to 4, a muddy water shield machine 10 has a cylindrical shield 12 disposed behind a cutter head 11 having a plurality of bits 11a, 11a,... The inner side of the shield 12 is divided by a partition wall 13 in the front-rear direction. A chamber 14 into which excavated earth and sand is taken is provided between the cutter head 11 and the partition wall 13, that is, behind the cutter head 11. The chamber 14 is connected with a mud pipe 15 attached to the partition wall 13, a mud pipe 16 and a gravel crushing device 17.

  As shown in FIG. 2, the cutter head 12 is rotatably attached to the partition wall 13 through a rotating shaft 19 that is rotated by driving of a driving motor 18.

  The mud pipe 15 supplies muddy water into the chamber 14 and is attached to the partition wall 13 with one end opened to the chamber 14.

  The mud pipe 16 stirs the earth and sand taken into the chamber 14 by excavation by the cutter head 11 and the mud water from the mud pipe 15 to make mud water, and discharges the mud water to the outside of the chamber 14. Therefore, one end side is opened in the chamber 14 and attached to the partition wall 13, and the other end side is connected to the pump 23 via the classifier 20.

  The gravel crushing device 17 secondarily crushes the gravel that cannot pass through the drainage pipe 16 so that the gravel diameter is large enough to pass through the pump 23, and includes a housing 24, a fixed tooth 26, a rotating shaft 27, and a drive motor. 28 and the rotation tooth | gear 29 are comprised as a single roll crusher. In the present embodiment, the gravel crushing device 17 and the mud discharge pipe 16 are integrated, and are detachably attached to the partition wall 13 with attachment bolts (not shown). Therefore, the gravel crushing device 17 and the mud drain pipe 16 are removed and exchanged when they are replaced with another type of gravel crushing device 17 and the mud pipe 16 or when maintenance inspection is performed by changing the working method. It has a structure that allows maintenance and inspection.

  The housing 24 is formed as a cylindrical body having an intake port 25a for taking in gravel on the front side facing the cutter head 11, and the rear surface 24a being closed. Further, a discharge port 25 b is provided on the peripheral surface 24 b of the housing 24, and the communication port 30 connects the discharge port 25 b and the intake port 32 a provided on the side surface of the sludge pipe 16. As shown in FIGS. 1 to 4, the housing 24 has an inner diameter on the intake port 25 a side of the mud pipe 16 so that gravel larger than the inner diameter of the mud pipe 16 can be taken in. It is formed in a cone shape as a whole so as to be larger than the inner diameter and gradually decrease toward the rear surface 24a. The housing 24 is attached to the partition wall 13 with the intake port 25a opened in the chamber 14, and is formed as a part of a passage for sending the mud water in the chamber 14 into the mud pipe 16 through the communication pipe 30. ing.

  A plurality of the fixed teeth 26 are provided on the inner side of the cone-shaped peripheral surface 24 b of the housing 24 so as to protrude from the inner side of the peripheral surface 24 b toward the center of the rotating shaft 27.

  The housing 24 is a housing formed in a cone-shaped substantially cylindrical shape in which the inner diameter of the intake port is larger than the inner diameter of the mud pipe and gradually decreases toward the rear side. There may be.

  The rotating shaft 27 is rotatably attached to the rear surface 24a of the housing 24 so as to penetrate the rear surface 24a of the housing 24 in the front-rear direction and extend in the front-rear direction in the housing 24. The rotary shaft 27 is connected to the drive motor 28 on the back side of the rear surface 24 a of the housing 24 and is rotated by the drive of the drive motor 28. Further, a plurality of rotating teeth 29 are attached to the outer peripheral surface of the rotating shaft 27 so as to rotate integrally with the rotating shaft 27.

  In this embodiment, the rotary shaft 27 rotates in the right direction (C direction indicated by an arrow in FIG. 4), and the right side is a gravel discharge side. As shown in FIGS. 3 and 4, the rotating shaft 27 to which the rotating teeth 29 are attached is eccentric to the left side with respect to the center of the housing 24, and on the gravel discharge side where the gap in the rotation direction is crushed. The gravel sent to the discharge side is sequentially sent into the communication pipe 30 through the discharge port 25b. Furthermore, if the size of the gap is changed, the crushed gravel diameter can be changed, and at the same time, the amount of crushed treatment per unit time can be changed.

  Further, as shown in FIG. 3 and FIG. 4, in the plane direction at a position higher than the vicinity of the rotation center of the rotating rotating tooth 29, the gravel is taken in the position where the gravel is taken in as well as the rotating tooth 29 rotating with the fixed tooth 26. The distance is the widest, and the distance between the fixed tooth 26 and the rotating tooth 29 decreases as it moves away from the partition wall 13, that is, toward the back side of the housing 24. However, in order to widen the gravel passage diameter range that is set at the position near the rotation center of the rotating rotating tooth 29 and becomes the discharge port 25b, the distance from the entrance to the back is the same.

  On the other hand, the connection angle between the gravel crushing device 17 and the sludge pipe 16 may not be vertical due to the internal space of the shield machine.

  Further, in this embodiment, the rotating shaft 27 can rotate on the rear surface 24a of the housing 24 so as to penetrate the rear surface 24a of the housing 24 in the front-rear direction and extend in the front-rear direction in the housing 24. However, it may be a position that goes directly to this embodiment.

  In this embodiment, the one end side of the mud discharge pipe 16 according to claim 2 is opened in the chamber 14 and is attached to the partition wall 13. Then, one end side is not opened in the chamber 14.

  Next, operation | movement of the mud shield shield machine 10 comprised in this way is demonstrated about FIGS. 1-4. In the structure shown in FIG. 1, a disk-shaped cutter head 11, which is a primary crusher provided on the front surface of the shield 12, is rotated by a drive motor 18, and a face is excavated by the cutter head 11. At the same time, mud water is supplied from the mud pipe 15 between the partition wall 13 and the face, and the inside of the chamber 14 is filled with pressurized mud water to stabilize the face, and the excavated earth and sand are taken into the mud water, which is discharged into the mud water. As shown in FIG. The chamber 14 is provided with an agitator (not shown) that stirs the muddy water in the chamber 14 and is driven by a drive motor (not shown).

  Of the gravel in the chamber 14 crushed by the cutter head 11 or passed as it is, gravel having a size that can be swallowed by the mud pipe 16 is swallowed as it is by the intake port 32b formed on the end face of the mud pipe 16. . On the other hand, gravel having a size that cannot be swallowed by the intake port 32b is taken into the housing 24 from the intake port 25a of the gravel crushing device 17, which is a secondary crusher. The taken gravel is crushed by the fixed teeth 26 and the rotating teeth 29 to a gravel diameter large enough to be swallowed by the sludge discharge pipe 16, and this is formed on the side of the discharge port 25 b, the communication pipe 30 and the sludge pipe 16. The gas is taken into the sludge pipe 16 through the intake port 32a provided in order. Further, the pump 23 is smoothly pumped to the ground by driving the pump 23.

  In the structure of the present embodiment, the communication port 30 connects the discharge port 25b of the housing 24, which is the discharge port of the gravel crushing device 17, and the intake port 32a provided on the side surface of the mud pipe 16. Therefore, the inside of the communication pipe 30 becomes a negative pressure due to the flow velocity inside the mud pipe 16. For this reason, the flow of the sludge water in the chamber 14 toward the sludge pipe 16 through the housing 24 and the communication pipe 30 is made smoothly, and the gravel excavated and crushed by the cutter head 11 is contained in the gravel crusher 17. And is crushed in the gravel crushing device 17, and then smoothly fed into the mud pipe 16 through the communication pipe 30. Thereby, the mud pipe 16 can stably take in the earth and sand containing gravel.

  Moreover, since the mud shield shield machine 10 comprised in this way can attach and detach the gravel crushing apparatus 17 and the waste mud pipe 16, the gravel crushing apparatus 17 arrange | positioned between the partition 13 and the classifier 20 is possible. In addition, the mud pipe 16 and the like can be exchanged.

  FIG. 5 shows an embodiment in which both a gravel crushing device 17 as a secondary crusher, a gravel collecting box 34 and a tertiary crusher 33 are provided. In this embodiment, the gravel sent to the classifier 20 through the gravel crusher 17 is crushed again into a gravel diameter that can pass through the pump 23 by the tertiary crusher 33, and classified. Discharge to the machine 20 side.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic structure sectional drawing at the time of mud shield digging for implementing this invention. The principal part expanded sectional view of a mud shield shield machine same as the above. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The BB line expanded sectional view of FIG. BRIEF DESCRIPTION OF THE DRAWINGS The schematic structure sectional drawing at the time of muddy water shield excavation for implementing this invention in the ground where a big gravel appears. Schematic configuration cross-sectional view during excavation by a general mud shield shield machine on the ground where the gravel diameter is not large or a small amount of gravel appears. The general composition sectional view at the time of excavation by the general mud shield shield machine of the ground where large gravel appears.

Explanation of symbols

10 Mud Shield Machine 11 Cutter Head 12 Shield 13 Bulkhead 14 Chamber 15 Mud Pipe 16 Mud Pipe 17 Gravel Crusher (Single Roll Crusher)
18 Drive motor 19 Rotating shaft 20 Classifier 21 Pump 23 Pump 24 Housing 24a Rear surface 24b Peripheral surface 25a Intake port 25b Discharge port

Claims (6)

A mud pipe and a mud pipe are connected to a chamber provided behind the cutter head via a partition wall, and mud water is sent into the chamber through the mud pipe, and the mud water mixed with the mud water and the cut soil is discharged. A muddy water shield machine that pumps the ground through a mud pipe and excavates the ground .
It has an intake port opened in the chamber and a discharge port connected to the intake port of the mud pipe, and is disposed as a part of a passage for sending the mud water in the chamber into the mud pipe. A housing in which the inner diameter of the intake port is larger than the inner diameter of the drainage pipe and gradually decreases toward the rear side, a fixed tooth attached to the inner peripheral surface of the housing, and the fixed tooth In a muddy shield excavator provided with a single roll crusher comprising a rotating tooth rotatably disposed in the housing opposite to the housing,
The rotation direction of the rotating teeth is set to the same direction as the rotation direction of the cutter head, and gravel contained in the cutting soil swallowed between the rotating teeth and the fixed teeth is at least from the inner diameter of the drainage pipe. A muddy water shield excavator characterized in that it is crushed to a small gravel diameter and sent to the discharge port side .   2. The muddy water shield machine according to claim 1, wherein the discharge port of the housing and the mud pipe opened in the chamber are connected by a communication pipe.   The muddy water shield machine according to claim 1 or 2, wherein a rotating surface of the rotating tooth rotates non-circularly.   4. The muddy water shield machine according to claim 1, wherein the single roll crusher and the mud pipe are configured to be detachable integrally with the partition wall. A mud pipe and a mud pipe are connected to a chamber provided behind the cutter head via a partition wall, and mud water is sent into the chamber through the mud pipe, and the mud water mixed with the mud water and the cut soil is discharged. In the muddy water shield method for excavating the ground by pumping to the ground via a mud pipe, the gravel contained in the waste mud water is obtained using the muddy water shield machine according to claim 1, 2, 3 or 4. A mud shield method characterized by crushing to a gravel diameter that can be pumped by a single roll crusher according to 2, 3 or 4, and pumping it to the ground. A mud pipe and a mud pipe are connected to a chamber provided behind the cutter head via a partition wall, and mud water is sent into the chamber through the mud pipe, and the mud water mixed with the mud water and the cut soil is discharged. In the muddy water shield method for excavating the ground, a gravel crushing device for crushing to a gravel diameter of a size that can pass through the pump is installed on the upstream side of a pump that is pumped to the ground via a mud pipe. While using the mud shield shield machine according to 3 or 4, the gravel having an outer diameter larger than the drainage pipe diameter among the gravel passing through the gravel crushing apparatus is crushed by the single roll crusher and sent to the drainage pipe. Then, after mixing with the waste water containing the gravel with a small outer diameter taken directly into the waste pipe through the waste pipe, the gravel contained in the mixed waste water is pumped by the gravel crushing device before the pump To a gravel diameter that can pass Muddy water shield method characterized by pumping to the ground by grinding.

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