JP7836731B2 - Tunnel boring machine and method for replacing the pressure sensor of the tunnel boring machine - Google Patents

Description

This invention relates to a tunnel boring machine and a method for replacing the pressure sensor of a tunnel boring machine.

Patent Document 1 discloses a tunnel boring machine equipped with a pressure detector capable of detecting the pressure inside a chamber into which excavated soil flows by the cutter head.

Japanese Patent Publication No. 2008-202321

Generally, in tunnel boring machines like the one described in Patent Document 1, the pressure inside the chamber is detected by a pressure detector installed in the partition wall, and the face is kept stable by controlling the detected pressure inside the chamber to be equivalent to the estimated pressure at the tunnel face. In other words, to maintain a more stable tunnel face, it is necessary to accurately grasp the pressure at the tunnel face.

The present invention aims to accurately determine the pressure at the tunnel face in a tunnel boring machine.

The present invention relates to a tunnel boring machine for excavating underground to construct a tunnel, comprising: a cylindrical body extending along the axial direction of the tunnel; an excavation section rotated at the front of the body; a partition wall provided inside the body and positioned opposite the excavation section in the axial direction of the tunnel; a chamber partitioned by the body, the excavation section, and the partition wall, where excavated soil and sand accumulate; a housing provided protruding into the chamber from the partition wall; and a pressure detector housed within the housing. The housing has a through-hole formed therein, exposing the pressure detection surface of the pressure detector to face the excavation section . An insertion tube is installed inside the housing coaxially with the through-hole, and the pressure detector is fixed to the insertion tube in an integrated state with the holding tube by being attached to the end of a holding tube inserted into the insertion tube. Furthermore, the present invention relates to a tunnel boring machine for excavating underground to construct a tunnel, comprising: a cylindrical body extending along the axial direction of the tunnel; an excavation section rotated at the front of the body; a partition wall provided inside the body and positioned opposite the excavation section in the axial direction of the tunnel; a chamber partitioned by the body, the excavation section, and the partition wall, where excavated soil is stored; a housing provided protruding into the chamber from the partition wall; and a pressure detector housed within the housing, wherein the housing has a through-hole formed to expose the pressure detection surface of the pressure detector opposite the excavation section, and the method for replacing the pressure detector of a tunnel boring machine includes the steps of: stopping the excavation section at a position where a portion other than the opening formed in the excavation section for taking excavated soil into the chamber faces the pressure detection surface of the pressure detector; removing the pressure detector from the housing; and attaching a pressure detector different from the removed pressure detector to the housing. Furthermore, the present invention relates to a tunnel boring machine for excavating underground to construct a tunnel, comprising: a cylindrical body extending along the axial direction of the tunnel; an excavation section rotated at the front of the body; a partition wall provided inside the body and positioned opposite the excavation section in the axial direction of the tunnel; a chamber partitioned by the body, the excavation section, and the partition wall, where excavated soil is stored; a housing provided protruding into the chamber from the partition wall; and a pressure detector housed within the housing, wherein the housing has a through-hole formed therein that exposes the pressure detection surface of the pressure detector opposite the excavation section, and a freezing pipe through which a refrigerant flows is provided around the through-hole in the housing, comprising a method for replacing the pressure detector of a tunnel boring machine, comprising the steps of: stopping the excavation section at a position where a portion other than the opening formed in the excavation section for taking excavated soil into the chamber faces the pressure detection surface of the pressure detector; flowing a refrigerant through the freezing pipe to form frozen soil around the pressure detection surface of the pressure detector; removing the pressure detector from the housing; and attaching a pressure detector other than the removed pressure detector to the housing.

According to this invention, the pressure at the tunnel face can be accurately determined in a tunnel boring machine.

This is a cross-sectional view showing the schematic configuration of a tunnel boring machine according to an embodiment of the present invention. This is an enlarged view of the tunnel boring machine as seen from the direction indicated by arrow A in Figure 1. This is an enlarged view showing section B of Figure 1. This is a diagram illustrating how to replace the pressure sensor. This figure shows a modified example of the mounting structure for the pressure detector, and is a cross-sectional view corresponding to Figure 3.

The embodiments of the present invention will be described below with reference to the drawings.

First, with reference to Figure 1, a tunnel boring machine according to an embodiment of the present invention will be described. The following description will focus on the case where the tunnel boring machine is a shield tunneling machine 100 used in the shield tunneling method. The shield tunneling machine 100 excavates through the ground (natural ground) to form a borehole, and then constructs a shield tunnel T (tunnel) by assembling the segment rings 112 (described later) to cover the inner wall of the borehole. Note that the present invention is also applicable to tunnel boring machines other than the shield tunneling machine 100, such as boring machines installed at the tip of a jacking pipe in the tunnel jacking method.

Figure 1 is a cross-sectional view showing the schematic configuration of the shield tunneling machine 100, and Figure 2 is a schematic view of the shield tunneling machine 100 as seen from the direction indicated by arrow A in Figure 1. Note that in Figure 2, the components other than the cutter head 20 are omitted from the illustration. In the following explanation, the face side, which is the direction in which the shield tunneling machine 100 moves, will be referred to as "forward," and the opposite direction, the tunnel entrance side, will be referred to as "rear."

As shown in Figure 1, the shield tunneling machine 100 is a slurry pressure type shield tunneling machine used in the slurry pressure shield tunneling method, and comprises a cylindrical front section 10, a cylindrical rear section 30, and a bendable section 40 that connects the front section 10 and the rear section 30.

The front section 10 comprises a cylindrical outer shell 11 (body) extending along the axial direction of the shield tunnel T, a cutter head 20 (excavation section) that is rotationally driven in front of the outer shell 11, and a partition wall 12 provided within the outer shell 11 and positioned opposite the cutter head 20 in the axial direction of the shield tunnel T. Note that the cross-sectional shape of the outer shell 11 is not limited to a circle; it may be elliptical or rectangular.

The cutter head 20 is a disc-shaped structure having an outer diameter approximately equal to the outer diameter of the outer shell 11. As shown in Figure 2, it has a plurality of spokes 21 extending radially from a rotation axis C1, an annular ring portion 22 to which the tips of the spokes 21 are connected, openings 23 formed between adjacent spokes 21, and a plurality of cutter bits 24 arranged at predetermined intervals in the circumferential and radial directions on the surface of the spokes 21 facing the excavation face. In the example shown in Figure 2, four spokes 21 are provided, but the number of spokes 21 is not limited to this; it may be three or fewer, or five or more. Furthermore, to add more cutter bits 24, a faceplate portion to which cutter bits 24 can be attached may be provided between adjacent spokes 21.

The soil excavated by the multiple cutter bits 24 protruding toward the excavation surface is guided through the openings 23 between the spokes 21 into the chamber 15, which is partitioned by the cutter head 20, the partition wall 12, and the outer shell 11. Furthermore, to agitate the excavated soil accumulated in the chamber 15, each spoke 21 is provided with a stirring rod 28 protruding toward the chamber 15, as shown in Figure 1.

The partition wall 12 rotatably supports an annular cutter drum 13 that rotates together with the cutter head 20, and also rotatably supports a rotary joint 17 connected to approximately the center of the cutter head 20.

The cutter drum 13 is connected to the spoke portion 21 of the cutter head 20 via multiple connecting rods 13a, and is rotationally driven by multiple motors 14 supported by a support wall 16 located on the rear side of the cutter drum 13. Therefore, by controlling the operation of the motors 14, it is possible to control the rotation direction and rotation speed of the cutter head 20. The motors 14 may be electric motors or hydraulic motors. The rotation axis C1, which is the rotation center of the cutter head 20, is approximately coincident with the central axis of the outer shell 11.

Inside the rotary joint 17, there are conductive wires that electrically connect the cutter head 20 side and the partition wall 12 side, as well as a flow path for supplying liquids such as additives from the partition wall 12 side to the cutter head 20 side.

Furthermore, the partition wall 12 is equipped with multiple fixed blades 18 that protrude into the chamber 15, as shown in Figure 1, in order to agitate the excavated soil accumulated in the chamber 15, together with the stirring rod 28 provided on the cutter head 20. The fixed blades 18 also serve as housings for the pressure detector 60, which will be described later.

In the embodiment shown in Figure 1, the fixed blade 18 and the stirring rod 28 are positioned such that the stirring rod 28 is radially outward from the fixed blade 18. However, the stirring rod 28 may also be positioned radially inward from the fixed blade 18, or it may be positioned both radially inward and radially outward from the fixed blade 18.

The shield tunneling machine 100 is further equipped with a screw conveyor 50 for transporting excavated soil accumulated in the chamber 15 to the rear of the shield tunneling machine 100.

The screw conveyor 50 comprises a cylindrical case 51 and an auger 52 incorporated inside the case 51. By rotating the auger 52 using a motor (not shown), the excavated soil in the chamber 15 is transported to the rear of the partition wall 12.

The rear section 30 comprises an outer shell 31 having the same cross-sectional shape as the outer shell 11 of the front section 10, an erector 33 for assembling the segment ring 112, a plurality of shield jacks 34 for advancing the shield tunneling machine 100, a backfill injection device 35 for injecting grout material between the inner circumferential surface of the excavated hole 110 drilled by the cutter head 20 and the outer circumferential surface of the segment ring 112, a circular shape retaining device 37 for maintaining the shape of the segment ring 112, and a support section 32 provided within the rear section 30 to support these devices. Note that the backfill injection device 35 and the circular shape retaining device 37 are optional and may not be provided.

The erector 33 is capable of gripping the arc-shaped segment piece 113 and is configured to move along the inner circumferential surface of the outer shell 31 in the direction of the outer shell's central axis C2 and in the circumferential direction. By assembling multiple segment pieces 113 along the inner circumferential surface of the outer shell 31 using the erector 33, a cylindrical segment ring 112 is constructed.

Multiple annular tail seals 31a are provided on the inner circumferential surface of the outer shell 31 at predetermined axial intervals to seal the gap between the outer shell 31 and the segment ring 112. The tail seals 31a are provided to prevent soil and water from entering the shield tunneling machine 100 through the gap between the outer shell 31 and the segment ring 112.

The shield jacks 34 are hydraulic jacks composed of a cylinder 34a and a rod 34b, and multiple jacks are arranged circumferentially at predetermined intervals inside the front end of the outer shell 31. By extending the shield jacks 34 with the tip of the rod 34b protruding from the cylinder 34a in contact with the side surface of the segment ring 112, the cutter head 20 is pressed against the ground by the reaction force obtained from the segment ring 112. In this way, the shield tunneling machine 100 uses the reaction force obtained by the shield jacks 34 pressing against the existing segment ring 112 as the propulsion force for forward excavation.

The folding section 40 includes a front section connecting portion 41 provided at the rear end of the front section 10 and having a concave spherical surface formed on its inner circumference, a rear section connecting portion 42 provided at the front end of the rear section 30 and having a convex spherical surface formed on its outer circumference that slides against the concave spherical surface of the front section connecting portion 41, and a plurality of folding jacks 43 provided between the front section 10 and the rear section 30.

The folding jack 43 is a hydraulic jack composed of a cylinder 43a and a rod 43b. The rod 43b is fixed to the front of the rear body 30 via a universal joint, and the cylinder 43a is fixed to the rear of the front body 10 via a universal joint.

By appropriately extending and retracting the folding jack 43 connected to the front section 10 and the rear section 30, the direction of the front section 10 relative to the rear section 30, that is, the direction of the rotation axis C1 relative to the central axis C2 of the rear section 30, can be bent in any direction. Note that the shield tunneling machine 100 may also be configured without the folding section 40.

Behind the shield tunneling machine 100, several follower carriages (not shown) are positioned to move in accordance with the machine's excavation. These follower carriages are used to transport control devices for managing the operation of the shield tunneling machine 100, power supply devices for the shield tunneling machine 100, and materials for constructing the shield tunnel T.

The shield tunneling machine 100 with the above configuration rotates the cutter head 20, transports soil by the screw conveyor 50, and extends the shield jacks 34 to excavate the ground. A borehole 110 is excavated in the ground, and a shield tunnel T is constructed by sequentially assembling segment rings 112 along the inner surface of the borehole 110. Grout material is injected into the gap between the inner surface of the borehole 110 and the outer surface of the segment rings 112 by a backfill injection device 35, and the segment rings 112 become firmly bonded to the ground via the grout material.

When the shield tunneling machine 100 constructs the shield tunnel T, the pressure inside the chamber 15 is controlled to be equal to the pressure at the tunnel face in order to suppress collapse at the excavation face. In other words, to maintain a more stable condition at the tunnel face, it is necessary to accurately understand the pressure at the tunnel face.

Therefore, in this embodiment, in addition to an earth pressure gauge (not shown) that detects the pressure inside the chamber 15, a pressure detector 60 is provided, which is arranged to detect the pressure at the tunnel face.

The pressure detector 60 is a strain gauge type or piezoelectric type pressure sensor, and as shown in Figure 3, it is housed within the fixed blade 18 (housing) so that the pressure detection surface 60a is exposed facing the cutter head 20 (excavation section). Figure 3 is an enlarged view of section B in Figure 1, and partially shows a cross-section to make the internal structure of the fixed blade 18 easier to understand.

As described above, since the pressure detector 60 is positioned so that its pressure detection surface 60a faces the cutting face, the pressure at the cutting face acts on the pressure detection surface 60a at all times, regardless of the rotation of the cutter head 20.

Therefore, the pressure detector 60 can continuously detect the pressure at the tunnel face.

As shown in Figure 3, the fixed wing 18 housing the pressure detector 60 is a cylindrical housing provided to open into the working space partitioned by the partition wall 12, the support wall 16, and the outer shell 11. It has a cylindrical portion 18a, one end of which is joined to the partition wall 12, and a bottom portion 18b that closes the other end of the cylindrical portion 18a facing the cutter head 20. A through hole 18c is formed in the bottom portion 18b to expose the pressure detection surface 60a of the pressure detector 60, facing the cutter head 20.

The fixed wing 18, configured in this way, contains a shut-off valve 66, one end of which is fixed to the bottom 18b, and a cylindrical insertion tube 67 connected to the other end of the shut-off valve 66. The shut-off valve 66 and the insertion tube 67 are positioned relative to the fixed wing 18 such that the passages formed inside them are coaxial with the through-hole 18c. These function as mounting parts 65 for attaching the pressure detector 60 to the fixed wing 18 in a predetermined orientation.

The shut-off valve 66 is a so-called ball valve that, when open, allows communication between the through-hole 18c and the insertion pipe 67, i.e., communication between the chamber 15 and the insertion pipe 67, and when closed, blocks communication between the through-hole 18c and the insertion pipe 67. Furthermore, when the shut-off valve 66 is in the open state, a space is formed within the shut-off valve 66 through which the retaining pipe 62 (described later) and the pressure detector 60 held by the retaining pipe 62 can be inserted. A hydraulic or pneumatic actuator for opening and closing the shut-off valve 66 is provided within the fixed vane 18.

Furthermore, the shut-off valve 66 is not limited to a ball valve; any type of valve device is acceptable as long as it can shut off communication between the chamber 15 and the insertion pipe 67, and has an internal through-hole through which the retaining pipe 62 and the pressure detector 60 can be inserted when the valve is open. For example, it could be a pinch valve or a gate valve. Also, the opening and closing operation of the shut-off valve 66 may be performed manually.

The insertion pipe 67 is a pipe material with a first flange portion 67a fastened to the flange of the shut-off valve 66 via a fastening member (not shown) at both ends, and a second flange portion 67b fastened to the flange portion 62b of the retaining pipe 62 (described later) via a fastening member (not shown) at both ends.

The pressure detector 60 is inserted and fixed into the mounting portion 65 of the above configuration, while being integrated with a cylindrical retaining tube 62 having a retaining end 62a capable of holding the pressure detector 60 and a flange portion 62b formed at the end opposite the retaining end 62a.

Specifically, the pressure detector 60 and the retaining tube 62, which are integrated by screwing or fitting a portion of the pressure detector 60 to the retaining end 62a of the retaining tube 62, are inserted into the mounting portion 65. Afterward, the flange portion 62b of the retaining tube 62 and the second flange portion 67b of the insertion tube 67 are fastened together via a fastening member (not shown), thereby securing them to a predetermined position within the fixed wing 18. The signal line 60b of the pressure detector 60 is routed through the inside of the retaining tube 62 and connected to a measuring device (not shown).

Furthermore, a sealing member 68 is provided on the inner circumferential surface of the insertion pipe 67, which is compressed between the insertion pipe 67 and the retaining pipe 62. This prevents excavated soil and groundwater from flowing into the work space through the gap between the insertion pipe 67 and the retaining pipe 62. The sealing member 68 may also be provided on the outer circumferential surface of the retaining pipe 62. Additionally, sealing members (not shown) may be appropriately provided on the contact surfaces between the bottom portion 18b and the shut-off valve 66, the contact surfaces between the shut-off valve 66 and the insertion pipe 67, and the contact surfaces between the flange portion 62b of the retaining pipe 62 and the second flange portion 67b of the insertion pipe 67. Furthermore, a sealing member in contact with the outer circumferential surface of the retaining pipe 62 may be provided inside the shut-off valve 66, similar to the sealing member 68.

In addition to the mounting portion 65 described above, a freezing pipe 70 through which refrigerant flows is attached to the fixed wing 18 so as to surround the through-hole 18c. By flowing a refrigerant such as liquid nitrogen through the freezing pipe 70 arranged around the through-hole 18c in this way, it becomes possible to form frozen soil around the pressure detection surface 60a of the pressure detector 60, as described later.

Furthermore, the flow path through which the refrigerant is supplied is not limited to the freezing pipe 70; it may be any flow path formed around the through-hole 18c, for example, a flow path formed within the bottom 18b, or a flow path formed within the flange on the bottom 18b side of the shut-off valve 66. Also, the supply of refrigerant to the freezing pipe 70 is performed only while the pressure detector 60 is being replaced, as described later.

As described above, the pressure detector 60 in this embodiment is housed in a relatively narrow space within the fixed wing 18 (housing), but it can be easily replaced in case of malfunction or other issues by following the procedure described below.

Next, referring to Figure 4, we will explain the specific method for replacing the pressure detector 60. Figures 4(a) to 4(c) are cross-sectional views corresponding to Figure 3, illustrating the method for replacing the pressure detector 60 in chronological order.

When replacing the pressure detector 60, first, as shown in Figure 4(a), the cutter head 20 is stopped at a predetermined position. Specifically, the cutter head 20 is stopped when the portion of the cutter head 20 other than the opening 23, for example, the spoke portion 21, is positioned facing the pressure detection surface 60a of the pressure detector 60 (excavation section stopping step). If a faceplate portion is provided between adjacent spoke portions 21, the cutter head 20 may be stopped when the faceplate portion is positioned facing the pressure detection surface 60a.

Next, refrigerant is flowed through the freezing tube 70, forming frozen soil around the pressure detection surface 60a of the pressure detector 60 (frozen soil formation step). When refrigerant is flowed through the freezing tube 70, for example, as shown by the dashed line in Figure 4(a), the area around the freezing tube 70 is cooled, forming frozen soil.

In forming frozen soil around the pressure-sensing surface 60a in this manner, as described above, the spoke portion 21 of the cutter head 20 is facing the pressure-sensing surface 60a. Therefore, there is not much excavated soil to be frozen around the pressure-sensing surface 60a. Consequently, it is possible to form frozen soil around the pressure-sensing surface 60a in a relatively short time.

Furthermore, by attaching a temperature sensor to the spoke portion 21 of the cutter head 20 facing the pressure detection surface 60a, it may be possible to check the formation status of frozen soil around the pressure detection surface 60a.

When it is confirmed that frozen soil has formed around the pressure detection surface 60a of the pressure detector 60, a retaining bolt 72 with a relatively long underhead length is installed in place of the fastening member (not shown) that was fastening the flange portion 62b of the retaining pipe 62 and the second flange portion 67b of the insertion pipe 67.

The retaining bolt 72 is attached by inserting it through a through hole (not shown) formed in the flange portion 62b of the retaining tube 62, and screwing its threaded portion into a female threaded hole (not shown) formed in the second flange portion 67b of the insertion tube 67.

By attaching the retaining bolt 72 using the through-hole or female thread hole used when fastening the retaining pipe 62 and the insertion pipe 67, the movement of the retaining pipe 62 along the insertion pipe 67 is restricted by the flange portion 62b of the retaining pipe 62 contacting the head of the retaining bolt 72.

Therefore, for example, even if the formation of frozen soil around the pressure detection surface 60a is insufficient and the pressure detector 60 and the retaining tube 62 are pressed by the pressure inside the chamber 15, the retaining tube 62 will not come out of the insertion tube 67, as this is prevented by the retaining bolt 72. Furthermore, to prevent the retaining tube 62 from coming out of the insertion tube 67, the movement of the retaining tube 62 may be restricted by a jack or the like, with its base supported by a partition wall 12 or support wall 16.

Furthermore, when it is confirmed that frozen soil has formed around the pressure detection surface 60a of the pressure detector 60, the extraction bolt 74 is attached to the flange portion 62b of the retaining pipe 62, as shown in Figure 4(a).

The extraction bolt 74 is a fully threaded bolt. Its threaded portion is screwed into a pre-formed female threaded hole (not shown) in the flange portion 62b of the retaining tube 62, and it is installed so that the tip surface of the threaded portion abuts against the second flange portion 67b of the insertion tube 67.

By rotating the extraction bolt 74 attached to the flange portion 62b of the retaining tube 62 in the tightening direction, that is, so that the threaded portion gradually extends from the flange portion 62b of the retaining tube 62 toward the second flange portion 67b of the insertion tube 67, the pressure sensor 60 is gradually pulled out from the mounting portion 65 together with the retaining tube 62.

Then, as shown in Figure 4(b), when the pressure detector 60 passes through the valve portion of the shut-off valve 66, the shut-off valve 66 is shut off (shutting-off process). This reliably prevents excavated soil and groundwater from flowing into the mounting portion 65 through the through-hole 18c.

Whether or not the pressure sensor 60 has passed the valve section of the shut-off valve 66 can be determined, for example, by whether or not the movement of the retaining tube 62 is restricted by the retaining bolt 72. In other words, the length of the retaining bolt 72 is set considering the length required for the pressure sensor 60 to pass the valve section of the shut-off valve 66. The opening and closing operation of the shut-off valve 66 is performed by an actuator (not shown).

Furthermore, in order to prevent excavated soil and groundwater from flowing in through the gap between the insertion pipe 67 and the retaining pipe 62 before the shut-off valve 66 is shut off, the sealing member 68 is installed in a position where it can perform its sealing function until the shut-off valve 66 is shut off, that is, as shown in Figure 4(b), in a position where it is compressed by the insertion pipe 67 and the retaining pipe 62 when the shut-off valve 66 is shut off.

When the shut-off valve 66 is shut off and there is no longer any risk of the pressure sensor 60 and retaining tube 62 being pressed by the pressure inside the chamber 15, the retaining bolt 72 and the extraction bolt 74 are removed, and as shown in Figure 4(c), the pressure sensor 60, together with the retaining tube 62, is withdrawn from the insertion tube 67.

This completes the removal process of detaching the pressure detector 60 from the fixed wing 18 (housing). Following the removal process, the installation process of attaching another pressure detector 60 to the fixed wing 18 is performed. The installation of the pressure detector 60 to the fixed wing 18 is performed in almost the reverse order of the removal procedure.

Furthermore, when inserting the pressure sensor 60 and the retaining pipe 62 into the insertion pipe 67, a jack or the like may be used to assist with the insertion force as needed. Also, when opening the shut-off valve 66 and moving the pressure sensor 60 toward the through-hole 18c, the retaining bolt 72 may be rotated in the tightening direction until the flange portion 62b of the retaining pipe 62 contacts the second flange portion 67b of the insertion pipe 67. Then, the second flange portion 67b of the insertion pipe 67 and the flange portion 62b of the retaining pipe 62 may be fastened together using a fastening member (not shown). Note that the extraction bolt 74 is not used in the installation process.

Through the above process, the replacement of the pressure detector 60 can be carried out safely and easily, under conditions where the inflow of excavated soil and groundwater through the through-hole 18c is prevented.

According to the above-described embodiment, the following effects and advantages are achieved.

In this embodiment, the pressure detector 60 is housed within the fixed wing 18 (housing) such that its pressure detection surface 60a is exposed facing the cutter head 20 (excavation section) through a through-hole 18c formed in the fixed wing 18. Because the pressure detector 60 is positioned so that its pressure detection surface 60a faces the working face, the pressure at the working face acts on the pressure detection surface 60a at all times, regardless of the rotation of the cutter head 20. Therefore, the pressure at the working face can be continuously and accurately determined based on the detection value of the pressure detector 60.

Furthermore, since the pressure detector 60 is housed within the fixed wing 18 (housing), the adhesion of clay or other materials to the pressure detection surface 60a of the pressure detector 60 is suppressed. As a result, it is possible to prevent the pressure detector 60 from falsely detecting pressure due to the adhesion of clay or other materials.

Furthermore, in this embodiment, the replacement of the pressure detector 60 is performed after stopping the cutter head 20 with the portion of the cutter head 20 other than the opening 23 facing the pressure detection surface 60a of the pressure detector 60, and then flowing refrigerant through the freezing pipe 70 to form frozen soil around the pressure detection surface 60a of the pressure detector 60. In particular, the removal of the pressure detector 60 from the insertion pipe 67 and the insertion of another pressure detector 60 into the insertion pipe 67 are performed with the shut-off valve 66, which can block communication between the chamber 15 and the insertion pipe 67, shut off.

Thus, the replacement of the pressure detector 60 can be performed safely and easily by removing the pressure detector 60 from the fixed vane 18 (housing) and attaching another pressure detector 60 to the fixed vane 18 (housing), while ensuring that excavated soil and groundwater from the chamber 15 do not flow into the insertion pipe 67 through the through-hole 18c.

Next, we will describe some variations of this embodiment. Note that the following variations are also within the scope of the present invention, and it is possible to combine the configurations shown in the variations with the configurations described in the above-described embodiments, or to combine the configurations described in the following different variations.

In the above embodiment, the shut-off valve 66 of the mounting portion 65, which is provided for mounting the pressure detector 60 within the fixed wing 18, is located on the bottom 18b side of the fixed wing 18. Alternatively, as shown in the modified example in Figure 5, the shut-off valve 66 may be located on the bulkhead 12 side. In this case, the flange portion 62b of the retaining pipe 62 is fastened to the flange portion 66a of the shut-off valve 66 via a fastening member (not shown), as shown in Figure 5. By arranging the shut-off valve 66 on the bulkhead 12 side in this way, it becomes possible to manually open and close the shut-off valve 66 and to easily check its open/closed state. Note that the shut-off valve 66 may also be located behind the bulkhead 12. Figure 5 shows a modified example of the mounting structure for the pressure detector 60, and is a cross-sectional view corresponding to Figure 3.

However, as shown in the modified example in Figure 5, if the shut-off valve 66 is positioned away from the through-hole 18c, when the pressure detector 60 is withdrawn from the mounting portion 65 along with the retaining pipe 62, the pressure in the space inside the insertion pipe 67 becomes negative. Even if frozen soil has formed, excavated soil and sand can easily flow into the insertion pipe 67 through the through-hole 18c. Furthermore, if the excavated soil and sand that have flowed into the insertion pipe 67 become jammed in the sliding part of the shut-off valve 66, there is a risk that the shut-off valve 66 will not be able to open or close properly.

Therefore, the insertion tube 67 is provided with an injection hole 67c for injecting replacement material into the insertion tube 67 from the bottom 18b side. A replacement material supply device (not shown) is connected to the injection hole 67c, and as the pressure detector 60 is withdrawn from the insertion tube 67, replacement material is gradually supplied from the replacement material supply device. This fills the insertion tube 67 with replacement material, preventing excavated soil and other debris from becoming trapped in the sliding part of the shut-off valve 66. Furthermore, in order to fill the space created when the pressure detector 60 is withdrawn with replacement material, it is preferable that the injection hole 67c be provided as close as possible to the through hole 18c. For example, the injection hole 67c may be provided not in the insertion tube 67, but within the bottom 18b of the fixed wing 18 such that one end opens at the through hole 18c.

As the replacement material, a relatively fluid, gel-like material (e.g., bentonite, clay, water glass) is used. When the pressure detector 60 is withdrawn, the replacement material filled into the insertion tube 67 is discharged through the injection hole 67c or through hole 18c when the new pressure detector 60 is inserted into the mounting portion 65 together with the retaining tube 62.

In the modified example shown in Figure 5, a first sealing member 68a is positioned near the flange portion 66a of the shut-off valve 66. Similar to the sealing member 68 in the above embodiment, this first sealing member 68a is provided to prevent excavated soil and groundwater from flowing in through the gap formed on the outer circumference of the retaining pipe 62 before the shut-off valve 66 is shut off.

Furthermore, in the modified configuration shown in Figure 5, the second sealing member 68b is positioned on the through-hole 18c side of the injection hole 67c. By providing the second sealing member 68b between the through-hole 18c and the injection hole 67c in this manner, excavated soil and groundwater are prevented from flowing into the work space and the injection hole 67c through the gap between the insertion pipe 67 and the holding pipe 62. Alternatively, instead of the second sealing member 68b, or in addition to the second sealing member 68b, a backflow prevention valve may be provided inside the injection hole 67c or on the passage connecting the injection hole 67c and the replacement material supply device to prevent excavated soil and groundwater from flowing into the replacement material supply device through the injection hole 67c.

Furthermore, in the above embodiment, although there is no hole for injecting the replacement material, as shown in the modified example in Figure 5 (injection hole 67c), an injection hole for injecting the replacement material may be provided in the flange portion on the through-hole 18c side of the shut-off valve 66 or in the bottom portion 18b of the fixed wing 18, in order to fill the space created inside the shut-off valve 66 with the replacement material when the pressure detector 60 is withdrawn through the shut-off valve 66 from the state shown in Figure 4(a) to the state shown in Figure 4(b).

Furthermore, in the above embodiment, as shown in Figure 4, the pressure detector 60 and the retaining tube 62 are inserted into and removed from the mounting portion 65 within the working space between the bulkhead 12 and the support wall 16. However, if the protrusion length of the fixed wing 18 from the bulkhead 12 is relatively long, and the length of the retaining tube 62 needs to be longer than the distance between the bulkhead 12 and the support wall 16, it becomes difficult to replace the pressure detector 60 using the procedure described above.

Therefore, if the retaining tube 62 needs to be relatively long, it may be configured to be divisible into multiple pipe sections in the axial direction, allowing the retaining tube 62 to be assembled or disassembled within the workspace when replacing the pressure detector 60. Alternatively, a hole large enough for the retaining tube 62 to pass through after being withdrawn from the mounting section 65 may be pre-formed in the support wall 16. This hole may then be used to insert and remove the pressure detector 60 and the retaining tube 62 from the mounting section 65 only when replacing the pressure detector 60.

Furthermore, in the above embodiment, when replacing the pressure detector 60, frozen soil is formed around the pressure detection surface 60a of the pressure detector 60. However, if the gap between the pressure detection surface 60a and the spoke portion 21 is relatively small, and the pressure inside the chamber 15 is relatively low, there is little risk of excavated soil or groundwater flowing in through the through-hole 18c in a short time. In such cases, it is not necessary to form frozen soil around the pressure detection surface 60a of the pressure detector 60.

Furthermore, in the above embodiment, the shield tunneling machine 100 is a so-called earth pressure balance type shield tunneling machine. Alternatively, the shield tunneling machine 100 may be a so-called slurry pressure type shield tunneling machine, equipped with a slurry supply and discharge device that supplies and discharges slurry into the chamber 15 to transport the excavated soil accumulated in the chamber 15 to the rear of the shield tunneling machine 100.

Although embodiments of the present invention have been described above, these embodiments represent only a portion of the applications of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

100... Shield tunneling machine (tunnel boring machine)
11... Outer shell (body)
12...Bulkhead 15...Chamber 18...Fixed wing (housing)
18c...Through hole 20...Cutter head (excavation part)
60... Pressure detector 60a... Pressure detection surface 65... Mounting part 66... Shut-off valve 67... Insertion pipe 70... Freezing pipe T... Shield tunnel (tunnel)

Claims (7)

A tunnel boring machine that excavates underground to construct a tunnel,
A cylindrical body extending along the axial direction of the tunnel,
A drilling section that is rotated at the front of the fuselage,
A partition wall is provided within the body and is positioned opposite the excavation section in the axial direction of the tunnel,
The chamber is partitioned by the aforementioned body, the aforementioned excavation section, and the aforementioned bulkhead, and is a chamber in which the soil excavated by the excavation section accumulates.
A housing is provided that protrudes from the partition wall into the chamber,
The enclosure includes a pressure detector housed within the aforementioned housing,
The housing has a through hole formed therein that exposes the pressure detection surface of the pressure detector facing the excavation portion .
An insertion tube is installed inside the housing so as to be coaxial with the through hole.
The pressure detector is fixed to the insertion tube in an integrated state with the retaining tube by being attached to the end of the retaining tube that is inserted into the insertion tube.
Tunnel boring machine. A freezing pipe through which refrigerant flows is provided around the through-hole of the housing.
The tunnel boring machine according to claim 1. A shut-off valve capable of blocking communication between the through-hole and the insertion pipe is provided between the through-hole and the insertion pipe.
The tunnel boring machine according to claim 1. The chamber is further provided with a stirring rod that protrudes from the excavation section into the chamber and is positioned radially close to the housing,
The aforementioned housing has fixed wings,
The sediment remaining in the chamber is agitated by the housing and the stirring rod.
A tunnel boring machine according to any one of claims 1 to 3 . A tunnel boring machine for excavating underground to construct a tunnel, comprising: a cylindrical body extending along the axial direction of the tunnel; an excavation section rotated at the front of the body; a partition wall provided inside the body and positioned opposite the excavation section in the axial direction of the tunnel; a chamber partitioned by the body, the excavation section, and the partition wall, where excavated soil is stored; a housing provided protruding from the partition wall into the chamber; and a pressure detector housed within the housing, wherein the housing has a through-hole formed therein that exposes the pressure detection surface of the pressure detector opposite the excavation section .
A step of stopping the excavation section at a position where a portion of the excavation section other than the opening formed in the excavation section for taking the excavated soil into the chamber faces the pressure detection surface of the pressure detector,
The steps include removing the pressure detector from the housing and
The process includes attaching a pressure detector, different from the one removed, to the housing,
Method for replacing the pressure sensor in a tunnel boring machine. A method for replacing the pressure detector of a tunnel boring machine, comprising: a tunnel boring machine for excavating underground to construct a tunnel, the machine comprising: a cylindrical body extending along the axial direction of the tunnel; an excavation section rotated at the front of the body; a partition wall provided inside the body and positioned opposite the excavation section in the axial direction of the tunnel; a chamber partitioned by the body, the excavation section, and the partition wall, where excavated soil and sand accumulates; a housing provided protruding from the partition wall into the chamber; and a pressure detector housed within the housing, wherein the housing has a through-hole that exposes the pressure detection surface of the pressure detector opposite the excavation section, and a freezing pipe through which a refrigerant flows is provided around the through-hole of the housing ;
A step of stopping the excavation section at a position where a portion of the excavation section other than the opening formed in the excavation section for taking the excavated soil into the chamber faces the pressure detection surface of the pressure detector,
The steps include flowing a refrigerant through the freezing pipe to form frozen soil around the pressure sensing surface of the pressure detector,
The steps include removing the pressure detector from the housing and
The process includes attaching a pressure detector, different from the one removed, to the housing,
Method for replacing the pressure sensor in a tunnel boring machine. The removal of the pressure detector from the housing is performed by removing the pressure detector from the insertion tube into which the pressure detector is inserted, which is provided inside the housing.
The attachment of the other pressure detector to the housing is performed by inserting the other pressure detector into the insertion tube.
The removal of the pressure detector from the insertion tube and the insertion of the other pressure detector into the insertion tube are performed with the shut-off valve, which is capable of blocking communication between the chamber and the insertion tube, closed.
A method for replacing a pressure detector in a tunnel boring machine according to claim 5 or 6 .