How to operate a shield tunneling machine

Abstract

To easily replace a gate installed behind a screw blade in a screw conveyor of a shield excavator.SOLUTION: A screw conveyor 10 installed in a mud pressure shield excavator has a cylindrical conveyor casing 10ca installed diagonally upward from a sediment intake end 10a where sediment in a chamber 6 are taken in, toward a sediment discharge end 10b where the taken sediment are discharged, a screw blade 10cb that takes in and transports the sediment into the conveyor casing 10ca, a first gate 21 installed behind the screw blade 10cb so that its opening degree can be adjusted, and adjusts the amount of sediment transported within the conveyor casing 10ca by the screw blade 10cb, and a second gate 22 installed adjacent to the first gate 21 on the screw blade 10cb side of the first gate 21, and that is movable between an open position for opening a path of the conveyor casing 10ca and a closed position for closing the path.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides How to operate a shield tunneling machine This is a technology related to this. [Background technology]

[0002] A shield tunneling machine is a machine that forms an excavation hole in the ground by pressing a cutter head attached to the front of the machine body against the face of the ground and moving forward while rotating.

[0003] Shield machines are divided into mud pressure shield machines and slurry shield machines. The former are designed to stabilize the tunnel face by injecting a slurry containing water-added bentonite or polymer flocculants into a chamber to turn the excavated soil into a slurry (fluidized) and applying a predetermined pressure. More specifically, the excavated soil fills the space between the tunnel face and the partition wall, and then injects and mixes it with a slurry to create a highly fluid and water-tight mud (a mixture of gravel and slurry). This slurry pressure stabilizes the tunnel face as the machine excavates. The soil mixed with the slurry in the chamber is then taken up by a screw conveyor and discharged from the rear of the machine. The latter are designed to stabilize the tunnel face by applying a predetermined pressure to the slurry in the chamber and transport the excavated soil by circulating the slurry.

[0004] In some earth pressure shield tunneling machines, a gate is installed behind the screw blades in the cylindrical conveyor casing that makes up the screw conveyor, and the gate's opening (i.e., the amount of earth transported by the screw conveyor) is adjusted to stabilize the face by adjusting the amount of earth taken into the screw conveyor from the chamber and controlling the earth pressure within the chamber. Specifically, when there is a risk that the earth pressure within the chamber will be lower than the earth-water pressure at the face due to high groundwater pressure in the excavated ground or other reasons, and the face will become unstable, the gate is used to reduce the radial opening area of ​​the screw conveyor or to close the pipeline, thereby restricting the amount of earth discharged, and increasing the earth pressure within the chamber to counteract the earth-water pressure at the face. Conversely, when the earth pressure within the chamber is higher than the earth-water pressure at the face, the gate is fully opened or the opening area is increased depending on the pressure difference to discharge earth.

[0005] In the case of a mud pressure shield tunneling machine in which a gate is installed behind the screw blades of such a screw conveyor to adjust the amount of mud discharged by the screw conveyor, the gate installed on the screw conveyor may malfunction due to the pressure of the mud being transported.

[0006] If a gate breaks down, the shield tunneling machine will stop excavating, the cutter head will stop rotating, the broken gate will be removed, and a new gate will be installed.

[0007] Regarding a shield tunneling machine in which gates are installed on the screw conveyor, the technology described in Patent Document 1 is known, for example. The technology described in Patent Document 1 is equipped with two water-stopping gates, and makes it possible to change the soil discharge path by selectively opening and closing the gates depending on the condition of the excavation face. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-097189 Summary of the Invention [Problem to be solved by the invention]

[0009] To replace the gate installed behind the screw blade, a large amount of waste soil remaining inside the screw conveyor must be removed, which requires a great deal of effort and results in a decrease in excavation efficiency.

[0010] The present invention has been made in light of the above-mentioned technical background, and aims to provide a technology that makes it possible to easily replace gates installed behind the screw blades in the screw conveyor of a shield tunneling machine. [Means for solving the problem]

[0011] In order to solve the above problem, the present invention as set forth in claim 1 How to operate a shield tunneling machine is a shield tunneling machine that excavates the ground and constructs a tunnel by injecting a mud-adding material into a chamber to turn the excavated soil introduced into the chamber into mud and applying a predetermined pressure to stabilize the face. The operation method of the present invention is such that the screw conveyor installed on the shield tunneling machine is a cylindrical conveyor casing installed diagonally upward from a sediment intake end where sediment is taken in from the chamber toward a sediment discharge end where the taken-in sediment is discharged; and screw blades installed along the axial direction within the conveyor casing, which take in sediment from the sediment intake end into the conveyor casing and transport it from the sediment discharge end to the outside of the machine. It consists of a gate body that moves up and down to adjust the opening degree, and a gate holding bar that is screwed along the width direction of the upper end of the gate body. The screw blade Installed at the rear a first gate that adjusts the amount of soil and sand transported in the conveyor casing by the screw blade; and a second gate that is installed adjacent to the first gate on the screw blade side of the first gate and is movable between an open position that opens the path of the conveyor casing and a closed position that closes the path. It hasWhen the opening angle of the first gate is adjustable, with the second gate in the open position, the shield machine excavates the natural ground while adjusting the amount of earth and sand transported by the screw blades in the conveyor casing with the first gate in accordance with the mud pressure in the chamber, and when the opening angle of the first gate becomes impossible to adjust, the excavation of the shield machine is stopped and the second gate is set to the closed position; The gate body of the first gate is removed by being detached from the gate retaining bar. At the same time, the soil between the first gate and the second gate is removed, and then a new Attaching a gate body to the gate retaining bar; It is characterized by:

[0012] The present invention as defined in claim 2 How to operate a shield tunneling machine In the invention described in claim 1, the surface of the first gate and the surface of the second gate are arranged parallel to each other.

[0013] The present invention as defined in claim 3 How to operate a shield tunneling machine In the invention described in claim 1 or 2, the first gate and the second gate are installed in a direction perpendicular to the direction in which the earth and sand are transported.

[0014] The present invention as defined in claim 4 How to operate a shield tunneling machine The invention according to any one of claims 1 to 3 is characterized in that a first jack and a second jack are provided to operate the first gate and the second gate, respectively. [Effects of the Invention]

[0016] In this invention, a first gate with an adjustable opening angle to adjust the amount of earth and sand transported is installed behind the screw blades installed axially inside the conveyor casing of the screw conveyor installed in the shield tunneling machine, and a second gate that opens and closes the path of the conveyor casing is installed adjacent to the first gate on the screw blade side of the first gate. Therefore, if the opening angle of the first gate becomes unadjustable, the second gate can be placed in a closed position to block the transport of earth and sand, making it easy to replace the first gate. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a configuration diagram showing the interior of an earth pressure shield machine according to an embodiment of the present invention from the side. [Figure 2] FIG. 2 is a front view of the cutter head of the earth pressure shield machine of FIG. 1. [Figure 3] 2 is an explanatory diagram of a first gate provided on a screw conveyor of the mud pressure shield machine of FIG. 1, viewed from the direction of earth and sand transport of the conveyor casing. FIG. [Figure 4] 2 is an explanatory diagram showing a second gate provided on the screw conveyor of the mud pressure shield machine of FIG. 1, viewed from the direction of earth and sand transport of the conveyor casing. FIG. [Figure 5] 3 is a flowchart showing an excavation process performed by the mud pressure shield machine of the present embodiment. [Figure 6] FIG. 2 is an explanatory diagram showing the gate positions of the first gate and the second gate when the mud pressure shield machine is excavating. [Figure 7] FIG. 10 is an explanatory diagram showing the procedure for dealing with a problem that occurs in the first gate. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings for explaining the embodiment, the same components are generally designated by the same reference numerals, and repeated description thereof will be omitted.

[0019] FIG. 1 is a configuration diagram showing the inside of an earth pressure shield machine of this embodiment from the side, and FIG. 2 is a front view of the cutter head of the earth pressure shield machine of FIG.

[0020] The mud pressure shield tunneling machine (shield tunneling machine) 1 of this embodiment is an equipment that generates mud pressure by excavating while filling the chamber between the cutter head 2 and the equipment body 3 with mud that is impermeable and has plastic fluidity (the ability to deform and move freely) by injecting and mixing mud-adding material into the soil and sand excavated by the cutter head 2, and then constructs an excavation tunnel with this mud pressure counteracting the earth pressure at the face.

[0021] The operation of the mud pressure shield machine 1 is controlled by an operator in a cab in a trailing carriage (not shown) located behind it.

[0022] The cutter head 2 is a member that excavates the natural ground face and is installed on the front surface of the equipment body 3 in a state in which it can rotate freely around the circumferential direction of the equipment body 3. For example, a disk-shaped spoke type cutter head 2 is adopted for this cutter head 2. That is, as shown in FIG. 2 , the cutter head 2 includes a hub portion 2a located at the center of rotation, six spoke portions 2b extending radially from the hub portion 2a toward the outer periphery, an intermediate ring portion 2c connecting the middle portions of the spoke portions 2b in the extension direction, an outer peripheral ring portion 2d connecting the tip ends of the spoke portions 2b, and through holes 2e formed between the spoke portions 2b for introducing excavated soil into the chamber 6.

[0023] A center bit (bit) 4a is attached to a hub portion 2a of the cutter head 2. Note that other excavation members such as a cone head type roller bit may also be attached to the hub portion 2a.

[0024] As shown in the figure, each spoke portion 2b of the cutter head 2 in this embodiment is formed so that its widthwise dimension (the direction of rotation of the cutter head 2) becomes wider from the center portion in the extension direction of the spoke portion 2b (here, slightly closer to the hub portion 2a than the attachment position of the intermediate ring portion 2c) to the inside (hereinafter referred to as the "inner peripheral side") as it moves away from the hub portion 2a, and so that the widthwise dimension becomes uniform from the center portion in the extension direction of the spoke portion 2b to the outside (hereinafter referred to as the "outer peripheral side"). However, the shape of the spoke portion 2b is not limited to this, and the spoke portion 2b may be formed to have the same width over the entire length of the spoke portion 2b, or may be formed so that it becomes wider over the entire length of the spoke portion 2b as it moves away from the hub portion 2a.

[0025] Each spoke 2b is fitted with a leading bit 4b that crushes boulders and excavates the natural ground, scraper teeth 4s that excavate the natural ground and collect the excavated soil into chamber 6 (Fig. 1), and wear-resistant steel plates 4t that protect both outer edges and surfaces on the inner periphery of the spoke 2b in the width direction. In addition to the leading bit 4b, other excavation components such as roller bits may also be fitted to the front of the spoke 2b.

[0026] The hub portion 2a and the spoke portions 2b are provided with a mud addition material inlet 5a. The mud addition material inlet 5a is a component for injecting mud addition material toward the face at the front of the cutter head 2.

[0027] A number of outer bits (bits) 4c are mounted in a row on the front face of the outer ring section 2d on the face side. Also, for example, two copy bits 4d are provided at opposite positions on the outer periphery of the outer ring section 2d. These copy bits 4d are used for over-excavation during sharp curve construction and for controlling the attitude of the earth pressure shield machine 1.

[0028] 1, the equipment main body 3 comprises a forward body plate 3a in the girder section and an aft body plate 3b in the tail section behind it. The forward body plate 3a and the aft body plate 3b are formed, for example, from cylindrical steel plates, and are members that form the outer shape of the equipment main body 3 and also form a hollow space inside the equipment main body 3. The forward body plate 3a and the aft body plate 3b are engaged with each other by inserting a spherical bearing portion at the tip of the aft body plate 3b into the forward body plate 3a at the aft end side of the forward body plate 3a while contacting the inner circumferential surface of the forward body plate 3a.

[0029] On the front side of the front body plate 3a, at a position set back from the front side towards the inside of the equipment body 3, there is provided a partition wall 7 that divides the hollow space inside the equipment body 3 into a face side and an inboard side. A chamber 6 is provided on the face side of this partition wall 7 (i.e., between the cutter head 2 and the partition wall 7), and on the inboard side of the partition wall 7 there are provided an additive injection section 5b, a cutter driver 8, a center bending jack 9a, a shield jack 9b, a screw conveyor 10, and an earth pressure detection section (not shown).

[0030] The additive injection section 5b is a device that injects additive toward the outside of the device main body 3 and into the chamber 6, and is provided near the outer periphery of the partition wall 7 with the injection port of the additive injection section 5b exposed to the outside of the device main body 3. The additive injected from the additive injection section 5b is, for example, a mud-making material such as a bentonite-based additive. Note that, for the additive injected from the additive injection section 5b, an aerated material may be used instead of the bentonite-based additive, or both a bentonite-based additive and an aerated material may be used.

[0031] The chamber 6 is a space into which the soil and sand excavated by the cutter head 2 is taken. Inside this chamber 6, a mixing blade 15, such as a cylindrical blade, protruding into the chamber 6 is provided on the front side of the partition wall 7, while a mixing blade 16, such as a cylindrical blade, protruding into the chamber 6 is provided on the back side of the cutter head 2. These mixing blades 15, 16 are offset from each other in the radial direction of the cutter head 2, and when the cutter head 2 rotates, they have the role of stirring and mixing the soil and sand that has entered the chamber 6 with the mud-adding material that has been injected into the chamber 6.

[0032] The cutter driver 8 is a drive source that rotates the cutter head 2. Here, an intermediate support drive system is exemplified as the cutter drive system, and as shown in FIG. 1, multiple cutter drivers 8 are arranged side by side along the circumferential direction of the cutter head 2 at positions approximately in the center between the center of the front surface of the cutter head 2 and the outer periphery.

[0033] The articulating jacks 9a are devices that connect the front and rear plates 3a and 3b and correct the forward movement direction of the earth shield machine 1, and as shown in Figure 1, multiple jacks are arranged side by side along the circumferential direction of the earth shield machine 1, at positions that straddle the boundary between the front and rear plates 3a and 3b within the equipment body 3. By supplying pressure oil to these articulating jacks 9a and propelling the earth shield machine 1 with the front and rear plates 3a and 3b bent in a predetermined direction and angle, it is possible to control the forward movement direction of the earth shield machine 1.

[0034] The shield jack 9b is a device that generates a propulsion force to advance the mud pressure shield machine 1 by receiving a reaction force from the segment SG installed at the rear of the equipment main body 3, and as shown in Figure 1, multiple shield jacks 9b are arranged in a row along the circumferential direction of the mud pressure shield machine 1 at a position within the equipment main body 3 that straddles the boundary between the front body plate 3a and the rear body plate 3b.

[0035] The screw conveyor 10 is a device for discharging the soil and sand taken into the chamber 6 outside the machine, and as shown in Figure 1, it extends continuously diagonally upward from the soil and sand intake end 10a, which penetrates the partition 7 at the bottom of the main body 3 and is located inside the chamber 6, to the soil and sand discharge end 10b, which is located at the rear of the main body 3 and slightly higher than the center of the height of the main body 3.

[0036] A soil discharge pipe (not shown) is connected to the soil discharge end 10b of the screw conveyor 10, and the soil transported to the soil discharge end 10b of the screw conveyor 10 is transported to a cart or the like through the soil discharge pipe.

[0037] The earth pressure detection unit is a sensor that converts the pressure of the mud inside the chamber 6 into an electrical signal via a strain gauge, and is installed with its earth pressure detection surface facing the inside of the chamber 6. The mud pressure shield machine 1 is designed to proceed with the excavation process while maintaining the stability of the face by managing the mud pressure inside the chamber 6 detected by the earth pressure detection unit so that it remains within a predetermined value range.

[0038] In the mud pressure shield machine 1, backfill material is injected into the gaps that form between the segments SG and the excavation wall surface as the machine advances. The purpose of injecting backfill material is to prevent ground subsidence and to stabilize the segments SG by integrating the segments SG with the natural ground, thereby preventing water leakage from the segment joints. Methods for injecting backfill material include an immediate injection method, in which backfill material is injected using backfill material injection ports (not shown) formed in the segments SG, and a simultaneous injection method, in which backfill material is injected in conjunction with excavation through a backfill material injection channel provided on the outer wall of the rear body plate 3b. In this embodiment, the immediate injection method is used, but the simultaneous injection method may also be used.

[0039] The screw conveyor 10 described above includes a cylindrical conveyor casing 10ca, which is installed diagonally upward from the sediment intake end 10a where sediment is taken in from the chamber 6 to the sediment discharge end 10b where the sediment is discharged, and a screw blade 10cb installed axially within the conveyor casing 10ca. The screw blade 10cb is used to take the sediment from the chamber 6 into the conveyor casing 10ca and transport it outside the machine. For example, a spiral ribbon screw without a rotating shaft is used. While screw conveyors with a rotating shaft are prone to blockage by boulders, ribbon screws can transport boulders with a maximum diameter greater than the radius of the conveying path, allowing them to transport boulders of a size that cannot be transported by screw conveyors with a rotating shaft. As a result, the mud pressure shield machine 1 of this embodiment is configured to take boulders of a size that can be discharged by the screw conveyor 10 into the chamber 6 without crushing them.

[0040] The screw blade 10cb may be an axial spiral screw blade in which a spiral blade is formed around a rotation axis, instead of an axial spiral ribbon screw as in this embodiment.

[0041] A first gate 21 is installed behind the screw blade 10cb to adjust the amount of soil and sand transported in the conveyor casing 10ca by the screw blade 10cb. Also, on the screw blade 10cb side of the first gate 21, a second gate 22 is installed adjacent to the first gate 21, opening and closing the transport path of soil and sand in the conveyor casing 10ca, and the faces of the gates 21 and 22 are installed parallel to each other.

[0042] The first gate 21 and the second gate 22 will be described below with reference to Figures 2 to 4. Here, Figure 3 is an explanatory diagram of the first gate as seen from the direction of sediment transport of the conveyor casing, and Figure 4 is an explanatory diagram of the second gate as seen from the direction of sediment transport of the conveyor casing.

[0043] As shown in Figures 2 and 3, the first gate 21 is installed at a position where the radial cross section of the conveyor casing 10ca is rectangular, making it possible to adjust the opening degree (i.e., adjust the cross-sectional area of ​​the soil transport path of the conveyor casing 10ca).

[0044] Specifically, the first gate 21 comprises a gate body 21a that moves up and down to adjust the opening degree, and a gate retaining bar 21b that is screwed to the upper end of the gate body 21a along the width direction of the gate body 21a.

[0045] The gate body 21a is formed in a rectangular shape slightly larger than the internal cross-sectional shape of the conveyor casing 10ca, has a predetermined thickness, and is installed so that it can move up and down in a direction perpendicular to the direction of transport of the soil and sand. As shown in the figure, when the gate body 21a moves to the bottom end, the soil and sand transport path is closed, and when it moves to the top end, the soil and sand transport path is fully opened.

[0046] Gate holding bar 21b attached to gate main body 21a is located at the top of conveyor casing 10ca, and a guide block 21ba is installed in the center in the width direction. The guide block 21ba has a guide hole (not shown) formed therein through which guide rod 10ca-1 attached to the top surface of conveyor casing 10ca penetrates. Therefore, when gate main body 21a moves up and down, guide block 21ba moves up and down along guide rod 10ca-1, allowing gate main body 21a to move up and down smoothly.

[0047] A pair of first cylinder jacks (first jacks) 23 equipped with rods 23a for vertically moving the first gate 21 are installed on both sides of the first gate 21. Furthermore, mounting plates 21bb rotatably attached to the tips of the rods 23a of the first cylinder jacks 23 are provided on both ends of the gate holding bar 21b.

[0048] The first cylinder jack 23 is a double-acting hydraulic jack with a freely adjustable extension / retraction amount of the rod 23a. Therefore, when the rod 23a of the first cylinder jack 23 extends or retracts, the gate body 21a moves up or down accordingly, and the vertical position of the gate body 21a is determined by the extension / retraction amount of the rod 23a, thereby adjusting the opening degree of the conveyor casing 10ca.

[0049] As shown in Figures 2 and 4, the second gate 22 is installed at a position where the radial cross section of the conveyor casing 10ca transitions from circular to rectangular, and is movable between an open position that fully opens the path of the conveyor casing 10ca (the soil transport path) and a closed position that closes the path.

[0050] Specifically, the second gate 22 comprises a gate body 22a that moves vertically to open and close the path of the conveyor casing 10ca, and a gate retaining bar 22b that is screwed to the upper end of the gate body 22a along the width direction of the gate body 22a.

[0051] As mentioned above, the second gate 22 is installed at a position where the radial cross section of the conveyor casing 10ca transitions from circular to rectangular, so that the screw blade 10cb side has an arc-shaped base that is slightly larger than the internal cross-sectional shape of the conveyor casing 10ca, and the first gate 21 side is formed into a rectangle that is slightly larger than the internal cross-sectional shape of the conveyor casing 10ca and has a predetermined thickness, and is installed so that it can move freely up and down in a direction perpendicular to the transport direction of the soil and sand.

[0052] As shown in the figure, when the gate body 22a of the second gate 22 moves to the lower end, the soil transport path is closed, and when it moves to the upper end, the soil transport path is fully opened.

[0053] As with the first gate 21 described above, in the second gate 22, the gate holding bar 22b attached to the gate main body 22a is located at the top of the conveyor casing 10ca, and a guide block 22ba is installed in the center in the width direction, with a guide hole (not shown) formed therein through which a guide rod 10ca-1 attached to the top surface of the conveyor casing 10ca passes. Therefore, when the gate main body 22a moves up and down, the guide block 22ba moves up and down along the guide rod 10ca-1, allowing the gate main body 22a to move up and down smoothly.

[0054] A pair of second cylinder jacks (second jacks) 24 equipped with rods 24a for vertically moving the second gate 22 are also installed on both sides of the second gate 22. Furthermore, mounting plates 22bb rotatably attached to the tips of the rods 24a of the second cylinder jacks 24 are provided on both ends of the aforementioned gate holding bar 22b.

[0055] The second cylinder jack 24 is also a double-acting hydraulic jack whose rod 24a can be freely adjusted in extension and retraction. Therefore, the vertical position of the gate body 22a is determined by the extension and retraction of the rod 24a of the second cylinder jack 24. However, as will be described later, the second cylinder jack 24 is used to move the second gate 22 between a position where it fully opens and a position where it closes the soil transport path, and does not adjust the opening of the conveyor casing 10ca.

[0056] Since the second cylinder jack 24 does not adjust the opening degree of the conveyor casing 10ca, a type of cylinder jack that cannot adjust the extension / contraction amount of the rod 24a may be used.

[0057] In this embodiment, the first gate 21 and the second gate 22 are arranged so that their surfaces are parallel to each other and the distance between the adjacent gates is as small as possible (for example, about 200 mm), but they do not necessarily have to be arranged parallel to each other. The advantages of narrowing the distance between the first gate 21 and the second gate 22 by arranging them parallel to each other will be described later.

[0058] In addition, in this embodiment, the first gate 21 and the second gate 22 are installed in a direction perpendicular to the direction of transport of the soil and sand, but they may be installed in a direction intersecting the direction of transport of the soil and sand, and are not necessarily installed in a perpendicular direction. However, if they are installed in a perpendicular direction, the pressure of the transported soil and sand is applied approximately evenly to the first gate 21 (gate body 21a) and the second gate 22 (gate body 22a), thereby stabilizing the movement of the gates.

[0059] Furthermore, the first gate 21 and the second gate 22 may be manually operated by an operator, in which case the first cylinder jack 23 and the second cylinder jack 24 are not required.

[0060] Next, excavation by the mud shield machine 1 of this embodiment will be explained using Figures 5 to 7. Here, Figure 5 is a flowchart showing the excavation process by the mud shield machine of this embodiment, Figure 6 is an explanatory diagram showing the gate positions of the first and second gates when the mud shield machine is excavating, and Figure 7 is an explanatory diagram showing the procedure for dealing with the situation when a problem occurs with the first gate.

[0061] First, the earth pressure shield machine 1 excavates the ground (step S01). That is, the cutter head 2 is pressed against the face and rotated while advancing the main body 3 to construct an excavation shaft in the ground. As the main body 3 advances, the annularly assembled segments SG are placed in the excavation shaft from the rear of the rear body plate 3b.

[0062] When excavating the natural ground, mud-adding material is added to the excavated soil taken into the face and chamber 6, and the soil and mud-adding material are stirred and mixed by the rotation of the cutter head 2 and the operation of the mixing blades 16 that follow that rotation, converting the excavated soil into mud with plastic fluidity and impermeability. This mud is then filled into chamber 6 and screw conveyor 10, and the filled mud is pressurized by the driving force of the shield jack 9b to generate mud pressure, which counteracts the earth pressure at the face, maintaining the stability of the face.

[0063] In addition, by injecting backfill material through the backfill material injection port formed in the segment SG to fill the gap that forms between the segment SG and the excavation wall surface, ground subsidence is prevented and the segment SG and the ground are integrated into a single structure, preventing water leakage from the segment joints and stabilizing the segment SG.

[0064] During such excavation, as shown in Figure 5, the second gate 22 is held in the open position by the second cylinder jack 24, and the opening of the first gate 21 is adjusted by the first cylinder jack 21, thereby controlling the mud pressure in the chamber 6 to be within a predetermined range and excavating the natural ground while maintaining the stability of the face. In other words, the natural ground is excavated while the amount of earth and sand transported in the conveyor casing 10ca by the screw blades 10cb is adjusted by the first gate 21 in accordance with the mud pressure in the chamber 6.

[0065] Then, it is determined whether the earth pressure shield machine 1 has excavated the ground and reached the arrival shaft (step S02), and if it has reached the arrival shaft, excavation ends (step S03).

[0066] On the other hand, if the arrival shaft has not been reached in step S02, it is determined whether a malfunction has occurred in the first gate 21 due to excavation (step S04). That is, when excavating the natural ground, the first gate 21, which adjusts its opening, is subjected to a load due to the pressure of mud transported inside the screw conveyor 10, and this may cause a malfunction and make it impossible to adjust the opening.

[0067] Then, if it is determined in step S04 that no malfunction has occurred in the first gate 21 (i.e., the first gate 21 is operating normally and the opening adjustment is being performed), the process returns to step S01 and excavation of the natural ground continues.

[0068] On the other hand, if it is determined in step S04 that a malfunction has occurred in the first gate 21 (i.e., the opening of the first gate 21 cannot be adjusted), it becomes necessary to remove the first gate 21 and replace it with a new first gate 21.

[0069] Therefore, in order to perform the replacement work of the first gate 21, first, the excavation of the earth pressure shield machine 1 is stopped (step S05). When the excavation of the earth pressure shield machine 1 is stopped, the rotation of the cutter head 2 also stops.

[0070] Next, as shown in Figure 6(a), the second gate 22 is closed by the second cylinder jack 24 (step S05). This blocks the transport of excavated soil by the screw conveyor 10, and the transported soil does not reach the first gate 21. Therefore, the malfunctioning first gate 21 (the opening of which has become uncontrollable) is removed (step S07), and the soil remaining between the first gate 21 and the second gate 22 is removed (step S08). Note that the order of steps S07 and S08 may be reversed, and the first gate 21 may be removed after the soil remaining between the first gate 21 and the second gate 22 is removed.

[0071] As described above, in this embodiment, the first gate 21 is composed of a gate body 21a for adjusting the opening degree and a gate holding bar 21b that is screwed along the width direction of the upper end of the gate body 21a, so that only the gate body 21a can be replaced by removing the gate body 21a from the gate holding bar 21b. However, if the first gate 21 has a structure in which the gate body 21a and the gate holding bar 21b are integrated, or if the gate holding bar 21b is not provided and the rod 23a of the first cylinder jack 23 is directly attached to the gate body 21a, then the entire first gate 21 must be removed.

[0072] Therefore, in this application, removing the first gate 21 and installing a new first gate 21 described below, i.e., replacing the first gate 21, includes not only replacing the entire first gate 21, but also replacing only the gate body 21a.

[0073] If the distance between the first gate 21 and the second gate 22 were wider, a large amount of sediment would be generated. However, in this embodiment, as described above, the first gate 21 and the second gate 22 are arranged so that the surfaces of the gates 21 and 22 are parallel to each other, narrowing the distance between the adjacent gates. This reduces the amount of sediment between the first gate 21 and the second gate 22, making it possible to remove the sediment in a short time. Furthermore, since the surfaces of the first gate 21 and the second gate 22 are arranged parallel to each other behind the screw blade 10cb, it is possible to minimize deterioration (drying, etc.) of the mud from inside the screw conveyor 10 to the discharge pipe.

[0074] Then, in steps S07 and S08, the defective first gate 21 is removed, and after the soil and sand between the gates is removed, the first gate 21 is replaced. That is, as shown in Fig. 6(b), the broken first gate 21 is removed, and as shown in Fig. 6(c), a new first gate 21 is installed (step S09).

[0075] Then, once the replacement of the first gate 21 is completed, as shown in Figure 6(d), the second gate 22 is returned to the open position using the second cylinder jack 24 (step S10), and the process returns to step S01 to resume excavation of the natural ground.

[0076] Thus, according to this embodiment, a first gate 21 with an adjustable opening angle to adjust the amount of sediment transported is installed behind the screw blade 10cb installed axially within the conveyor casing 10ca of the screw conveyor 10 installed in the earth pressure shield machine 1, and a second gate 22 for opening and closing the path of the conveyor casing 10ca is installed adjacent to the first gate 21 on the screw blade 10cb side of this first gate 21. Therefore, when the opening angle of the first gate 21 becomes unadjustable, the second gate 22 can be placed in the closed position to block the transport of sediment, making it possible to easily replace the first gate 21.

[0077] Although the invention made by the inventor has been specifically described above based on the embodiments, the embodiments disclosed in this specification are illustrative in all respects and should not be considered to be limited to the disclosed technology. In other words, the technical scope of the present invention should not be interpreted restrictively based on the description of the above embodiments, but should be interpreted solely in accordance with the description of the claims, and includes technologies equivalent to the technologies described in the claims and all modifications within the scope of the claims.

[0078] For example, in the above embodiment, a ribbon screw is used for the screw blade 10cb, but this is not limited to this and various modifications are possible, for example, a screw blade that combines a ribbon type and a shaft type may be used. [Industrial Applicability]

[0079] The above explanation has been given of the application of the present invention to an intermediate support drive type earth pressure shield machine, but the present invention is not limited to this and can also be applied to other shield machines, such as center shaft drive type or peripheral support drive type earth pressure shield machines. [Explanation of symbols]

[0080] 1. Mud pressure shield tunneling machine (shield tunneling machine) 2 cutter heads 6 Chambers 10 Screw conveyor 10a Sediment intake end 10b Sediment discharge end 10ca conveyor casing 10ca-1 guide rod 10cb screw blade 21 First Gate 21 First cylinder jack 21a Gate body 21b Gate retaining bar 21ba guide block 21bb mounting plate 22 Second Gate 22a Gate body 22b Gate retaining bar 22ba guide block 22bb mounting plate 23 First Cylinder Jack (First Jack) 23a Rod 24 Second cylinder jack (second jack) 24a Rod

Claims

1. A method for operating a shield machine that excavates natural ground while stabilizing a tunnel face by injecting a mud-adding material into a chamber to turn the excavated soil introduced into the chamber into mud and applying a predetermined pressure, comprising: The screw conveyor installed on the shield tunneling machine is a cylindrical conveyor casing installed obliquely upward from a sediment intake end where sediment is taken into the chamber toward a sediment discharge end where the taken-in sediment is discharged; A screw blade is installed along the axial direction inside the conveyor casing, and takes in soil and sand from the soil intake end into the conveyor casing and transports it from the soil discharge end to the outside of the machine; a first gate, which is installed behind the screw blade and which is composed of a gate body that moves up and down to adjust the opening degree and a gate holding bar that is screwed along the width direction of the upper end of the gate body, and which adjusts the amount of soil and sand transported in the conveyor casing by the screw blade; a second gate that is installed adjacent to the first gate on the screw blade side of the first gate and is movable between an open position that opens the path of the conveyor casing and a closed position that closes the path; It has When the opening angle of the first gate is adjustable, the second gate is set in an open position, and the shield machine excavates the natural ground while adjusting the amount of earth and sand transported by the screw blades in the conveyor casing with the first gate in accordance with the mud pressure in the chamber; When the opening degree of the first gate can no longer be adjusted, the excavation of the shield machine is stopped, the second gate is placed in a closed position, the gate body of the first gate is detached and removed from the gate holding bar, and the soil and sand between the first gate and the second gate are removed, and then a new gate body is attached to the gate holding bar. A method for operating a shield tunneling machine.

2. The first gate surface and the second gate surface are arranged parallel to each other.

2. A method for operating a shield tunneling machine according to claim 1.

3. The first gate and the second gate are installed in a direction perpendicular to the direction of transport of soil and sand.

3. A method for operating a shield tunneling machine according to claim 1 or 2.

4. a first jack and a second jack are provided to operate the first gate and the second gate, respectively; A method for operating a shield tunneling machine according to any one of claims 1 to 3.

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