Tunnel excavation method and tunnel excavator

Abstract

To make it possible to cut obstacles in excavating a tunnel with a non-complete circular cross section.SOLUTION: A tunnel excavation method includes a step of identifying an obstacle location within an excavation cross section on the basis of a third shaft center location within the excavation cross section obtained from a detection result of a first angle sensor 52 and a second angle sensor 54 and a load of a cutter rotating around the third shaft center detected by a load sensor 58, and a step of excavating an obstacle.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a tunnel boring method and a tunnel boring machine. [Background technology]

[0002] For example, Patent Document 1 discloses a tunnel boring machine that cuts obstacles. This tunnel boring machine has a cutter head rotatably supported on the front body of a cylindrical boring machine body, and is configured so that a plurality of earth and sand cutting bits and a plurality of obstacle cutting bits are provided on first to fourth cutter spokes that are tapered and inclined like a cone of the cutter head, and a large number of obstacle cutting bits are provided on the first to fourth cutter face plates.

[0003] "Obstacles" here refer to objects buried in the ground (underground) that impede excavation, such as man-made structures made of steel, concrete, etc., such as pipes, electrical conduits, and retaining walls (steel sheet piles). "Cutting out obstacles" refers to cutting out obstacles to a size that can be removed from the tunnel boring machine as excavation material.

[0004] Furthermore, Patent Document 2 discloses a shield machine capable of excavating a non-circular cross-sectional shape. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-196386 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-039976 Summary of the Invention [Problem to be solved by the invention]

[0006] In the tunnel boring machine disclosed in Patent Document 1, the cutter head is rotated to cut away obstacles along with the natural ground, forming a borehole with a circular cross section that corresponds to the outer diameter of the cutter head. As such, methods of cutting away obstacles in tunnel boring machines that excavate tunnels with circular cross sections are conventionally known.

[0007] On the other hand, Patent Document 2 does not disclose a method for appropriately cutting obstacles when excavating a tunnel with a non-circular cross section. A method for appropriately cutting obstacles is also desired when excavating a tunnel with a non-circular cross section as disclosed in Patent Document 2.

[0008] An object of the present invention is to provide a tunnel excavation method and a tunnel excavating machine that are capable of cutting away obstacles when excavating a tunnel with a non-circular cross section. [Means for solving the problem]

[0009] According to one aspect of the present invention, in a tunnel excavation method for excavating a tunnel using a tunnel boring machine comprising a body capable of supporting an inner wall of natural ground and an excavation unit attached to the body and excavating the natural ground, the excavation unit comprises: a first member configured to be rotatable about a first axis parallel to the axis of the tunnel; first driving means for rotating the first member about the first axis; a second member supported by the first member to be rotatable about a second axis parallel to the first axis and located at a distance from the first axis; second driving means for rotating the second member about the second axis; The tunnel excavation method includes a cutter that is movably supported on a second member, a third drive means that rotates the cutter around a third axis, a first detection unit that detects the rotational position of the second axis relative to the first axis, a second detection unit that detects the rotational position of the third axis relative to the second axis, and a load detection unit that detects the load on the cutter, and includes a step of identifying the position of an obstacle within the excavation cross section based on the position of the third axis within the excavation cross section obtained from the detection results of the first detection unit and the second detection unit and the load on the cutter rotating around the third axis detected by the load detection unit, and a step of excavating the obstacle whose position has been identified.

[0010] According to one aspect of the present invention, in a tunnel excavation method for excavating a tunnel using a tunnel boring machine having a body capable of supporting an inner wall of natural ground and an excavation unit attached to the body and excavating the natural ground, the excavation unit comprises: a first member configured to be rotatable about a first axis parallel to the axis of the tunnel; first driving means for rotating the first member about the first axis; a second member supported by the first member to be rotatable about a second axis parallel to the first axis and spaced apart from the first axis; and a cutter supported by the second member so as to be rotatable about a third axis parallel to the second axis and spaced apart from the second axis. The tunnel excavation method includes a step of excavating the ground by moving the cutter along an excavation trajectory whose outer edge forms an excavation cross section that is non-circular, and a step of cutting an obstacle within the excavation cross section, wherein in the step of cutting the obstacle, the cutter is moved along an inner trajectory at least a portion of which passes inside the excavation trajectory to cut the obstacle.

[0011] According to one aspect of the present invention, a tunnel boring machine for excavating a tunnel comprises a body capable of supporting an inner wall of natural ground, an excavation unit attached to the body for excavating the natural ground, and a control unit for controlling the operation of the excavation unit, wherein the excavation unit comprises a first member configured to be rotatable about a first axis parallel to the axis of the tunnel, first drive means for rotating the first member about the first axis, a second member supported by the first member to be rotatable about a second axis parallel to the first axis and spaced apart from the first axis, second drive means for rotating the second member about the second axis, and a second drive means for rotating the second member about the second axis and spaced apart from the second axis. The excavation device includes a cutter rotatably supported by the second member at a third axis located at a distance, a third drive means for rotating the cutter around the third axis, a first detection unit for detecting the rotational position of the second axis relative to the first axis, a second detection unit for detecting the rotational position of the third axis relative to the second axis, and a load detection unit for detecting the load on the cutter, and the control unit identifies the position of an obstacle within the excavation cross section based on the position of the third axis within the excavation cross section obtained from the detection results of the first detection unit and the second detection unit, and the load on the cutter rotating around the third axis detected by the load detection unit. [Effects of the Invention]

[0012] According to the present invention, obstacles can be cut away when excavating a tunnel with a non-circular cross section. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing the configuration of a shield tunneling machine according to an embodiment of the present invention. FIG. [Figure 2] FIG. 1 is a schematic diagram showing the configuration of the excavation section of a shield machine according to an embodiment of the present invention, as viewed from the face side along the axial direction of the tunnel. [Figure 3] 2 is a schematic diagram showing a cutter of a shield machine according to an embodiment of the present invention, as viewed from a direction perpendicular to the axial direction of the tunnel as indicated by arrow A in FIG. 2. FIG. [Figure 4] 1 is a block diagram showing the configuration of a shield tunneling machine according to an embodiment of the present invention. FIG. [Figure 5] 1 is a schematic diagram showing the configuration of the excavation section of a shield machine according to an embodiment of the present invention using a two-link model. [Figure 6] 1A and 1B are schematic diagrams for explaining the inner cutting process of the tunnel excavation method according to an embodiment of the present invention, in which (a) is a diagram showing the trajectory of the cutter as viewed from the axial direction of the tunnel, and (b) is an enlarged view of part VIB in FIG. 1 showing the trajectory of the cutter. [Figure 7] FIG. 2 is a schematic diagram for explaining the reciprocating cutting process of the tunnel excavation method according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram for explaining the side cutting process of the tunnel excavation method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] A tunnel boring machine according to an embodiment of the present invention will be described below with reference to the drawings. In the following, a case will be described in which the tunnel boring machine is a shield machine 100 used in a shield tunneling method. The shield machine 100 excavates the ground (natural ground) to form an excavation hole 1, and constructs a tunnel T by assembling segment rings 10 (lining) to cover the inner wall of the excavation hole 1. Note that the present invention can also be applied to tunnel boring machines other than the shield machine 100, for example, an excavation machine installed at the end of a jacking pipe in a jacking method.

[0015] In the following description, as shown in FIG. 1, the tunnel face side, which is the direction in which the shield machine 100 advances, is referred to as the "front," and the tunnel mouth side, which is the opposite direction, is referred to as the "rear."

[0016] The shield machine 100 of this embodiment is a mud pressure type shield machine 100 used in a mud pressure shield tunneling method.

[0017] 1, the shield machine 100 comprises a skin plate 11 as a cylindrical body extending along the axial direction of tunnel T and capable of supporting the inner wall of excavation hole 1, an excavation section 20 provided in front of skin plate 11 for excavating the natural ground, a jack 15 (propulsion device) for advancing excavation section 20 toward the natural ground, a partition wall 13 provided within skin plate 11 and positioned opposite excavation section 20 in the axial direction of tunnel T, a cutter chamber 14 into which earth excavated by excavation section 20 flows, and a screw conveyor 40 (discharge mechanism) for discharging the earth in cutter chamber 14 to the rear of the shield machine 100. Segment rings 10 are constructed sequentially on the rear side of the interior of skin plate 11 as the shield machine 100 advances.

[0018] A jack 15 is fixed to the skin plate 11. The jack 15 receives a reaction force from the segment ring 10 and propels the skin plate 11 forward, pressing a cutter 25 of the excavation section 20, which will be described later, against the natural ground. When the skin plate 11 is propelled forward and the segment ring 10 leaves the skin plate 11, a backfill material (not shown) is filled between the outer peripheral surface of the segment ring 10 and the inner wall of the excavation hole 1.

[0019] The cutter chamber 14 is set in an area partitioned by the inner peripheral surface of the skin plate 11, the end face of the skin plate 11 on the face side, and the end face of the partition wall 13 on the face side. Excavated earth and groundwater flow into the cutter chamber 14 and accumulate there.

[0020] The screw conveyor 40 is provided so as to face the cutter chamber 14 through an opening provided in the partition wall 13 .

[0021] The screw conveyor 40 has a cylindrical case 41, an auger 42 incorporated inside the case 41, and a gate 43 configured to open and close a discharge port 41a of the case 41. The screw conveyor 40 is configured to be able to transport excavated soil and sand from the cutter chamber 14 when the auger 42 is rotated by a motor (drive unit) not shown. The front side of the case 41 serves as a soil and sand inlet connected to the cutter chamber 14, and the rear side has a discharge port 41a that serves as a soil and sand outlet. Although not shown in detail, the gate 43 is opened and closed by a motor (drive unit) not shown to adjust the opening area of ​​the discharge port 41a of the case 41.

[0022] The amount of soil and sand in the cutter chamber 14 is adjusted by the amount of soil and sand excavated by the excavation unit 20 and the amount of soil and sand discharged by the screw conveyor 40. The amount of soil and sand discharged by the screw conveyor 40 is adjusted by the rotation speed of the auger 42 and the opening degree of the gate 43 (in other words, the opening area of ​​the discharge port 41a of the case 41).

[0023] 1 and 2, the excavation unit 20 includes a rotor 21 (first member) configured to be rotatable about a first axis O1 parallel to the axis of the tunnel T, a first driving means 30 that rotates the rotor 21 about the first axis O1, a frame 23 (second member) supported by the rotor 21 so as to be rotatable about a second axis O2 that is parallel to the first axis O1 and spaced apart from the first axis O1, a second driving means 32 that rotates the frame 23 about the second axis O2, a cutter 25 supported by the frame 23 so as to be rotatable about a third axis O3 that is parallel to the second axis O2 and spaced apart from the second axis O2, and a third driving means 34 that rotates the cutter 25 about the third axis O3. The cutter 25 faces the natural ground and excavates it.

[0024] The rotating body 21 is located in front of the partition wall 13 and is rotatably attached to the partition wall 13. The rotating body 21 is rotatable around a first rotation axis 22 located at the first axis O1. The first axis O1 is parallel to (more strictly, coincides with) the central axis of the skin plate 11 of the shield tunneling machine 100. The rotating body 21 has a cutter bit (not shown) on the opposing surface facing the working face, and has the excavation performance to be pressed against the natural ground to excavate. Note that the rotating body 21 does not necessarily have to have excavation performance.

[0025] 1, the first driving means 30 has one or more electric motors 31 provided inside the skin plate 11. The first driving means 30 drives the rotating body 21 to rotate about a first axis O1.

[0026] The frame 23 is attached to the front surface of the rotor 21, which is the cutting face side, and is located in front of the rotor 21. The frame 23 is also located inside the cutter chamber 14. The frame 23 is attached to the rotor 21 so as to be rotatable about a second axis O2 that is parallel to the first axis O1 and spaced radially from the first axis O1. As shown in FIG. 1 , the frame 23 is attached to the rotor 21 via a second rotation shaft 24, one end of which is located at the second axis O2. The frame 23 is formed in the shape of an arm extending in a direction approximately perpendicular to the first rotation shaft 22.

[0027] The second driving means 32 has one or more electric motors 33 provided on the rotating body 21. The frame 23 is driven to rotate about the second axis O2 by the second driving means 32. Furthermore, since the frame 23 is attached to the rotating body 21 at a position spaced apart from the first axis O1, the frame 23 also rotates about the first axis O1 as the rotating body 21 rotates.

[0028] As shown in FIG. 2 , the cutter 25 is located in front of the frame 23 at the other end opposite to the end of the frame 23 attached to the rotor 21, and is rotatably attached to the frame 23. The cutter 25 is rotatably attached to the frame 23 via a third rotation shaft 26 located on a third axis O3 that is parallel to the second axis O2 and radially spaced from the second axis O2 (and the first axis O1). The third axis O3 coincides with the central axis of the cutter 25. Therefore, the cutter 25 can rotate around the third axis O3, i.e., spin on its own axis. The first axis O1 and the second axis O2 are disposed on the frame 23 at a predetermined distance apart. In the longitudinal direction, the cutter 25 is located outside the cutter chamber 14, more specifically, forward (toward the face) of the end surface (end) of the face-side skin plate 11.

[0029] The cutter 25 is configured to be rotatable about the third axis O3, and to be able to rotate (revolve) about the first axis O1 in response to the rotation of the rotor 21 and the frame 23. The cutter 25 is also capable of moving to a region radially outward from the end of the skin plate 11 in a cross section perpendicular to the axis of the tunnel T, and is therefore able to excavate the natural ground.

[0030] As shown in FIG. 2, the cutter 25 has a plurality of spokes 27 that are provided perpendicularly (radially) to a third axis O3 that is the rotation axis of the cutter 25, and a plurality of cutter bits 28 that protrude from the spokes 27.

[0031] The spokes 27 are arranged in a row at equal angular intervals in the circumferential direction of the third axis O3. As shown in FIG. 3 , the front surface of each spoke 27 facing the natural ground has a vertical surface 27a perpendicular to the first axis O1, and a first inclined surface 27b and a second inclined surface 27c disposed around the vertical surface 27a and inclined with respect to both the vertical surface 27a and the first axis O1. The first inclined surface 27b and the second inclined surface 27c are inclined relative to each other. Each spoke 27 also has an outer surface 27d substantially parallel to the first axis O1. The vertical surface 27a, the first inclined surface 27b, the second inclined surface 27c, and the outer surface 27d of each spoke 27 form an excavation surface on which a cutter bit 28 is provided. The vertical surface 27a, the first inclined surface 27b, the second inclined surface 27c, and the outer surface 27d are connected to adjacent surfaces in this order as they move radially outward from the third axis O3.

[0032] The cutter bits 28 are provided on the vertical surface 27a, the first inclined surface 27b, the second inclined surface 27c, and the outer surface 27d of the spokes 27, and protrude from the surfaces on which they are provided. That is, the cutter bits 28 provided on the vertical surface 27a of the spokes 27 protrude forward, and the cutter bits 28 provided on the outer surface 27d protrude in a direction perpendicular to the first axis O1. Furthermore, the cutter bits 28 provided on the first inclined surface 27b and the second inclined surface 27c protrude in directions inclined relative to the front (both forward and in the direction perpendicular to the first axis O1).

[0033] The cutter bits 28 provided on the vertical surfaces 27a of the spokes 27 form a front excavation section 25a capable of excavating the front surface in the traveling direction, which is a surface perpendicular to the first axis O1. In addition, the cutter bits 28 provided on the first inclined surface 27b and the second inclined surface 27c form a side excavation section 25b capable of excavating an inclined surface inclined relative to the front surface in the traveling direction. In this way, the cutter 25 can exert an excavation ability toward the front and an excavation ability to excavate from the inner periphery of the excavated hole 1 (in other words, an excavation ability in a radial direction relative to the first axis O1).

[0034] 1, the third driving means 34 has one or more electric motors 35 attached to the frame 23. The cutter 25 rotates about the third axis O3 by the third driving means 34. Because the cutter 25 is attached to the frame 23 at a position spaced apart from the second axis O2, the cutter 25 is rotatable about the first axis O1 together with the frame 23, and is also rotatable about the second axis O2 in conjunction with the rotation of the frame 23 about the second axis O2.

[0035] The cutter 25 rotates around the third axis O3 and the first axis O1 while being pressed against the natural ground, whereby the cutter bit 28 excavates the natural ground to form the excavation hole 1. The earth and sand excavated by the cutter 25 accumulates in the cutter chamber 14.

[0036] 1 and 2, a plurality of stirring blades 29 extending in the radial direction of the second axis O2 are provided on one end side of the frame 23. The stirring blades 29 rotate together with the frame 23, thereby stirring the soil and sand remaining in the cutter chamber 14.

[0037] In this embodiment, the rotor 21 is rotatable in both directions about the first central axis O1, but may be rotatable in one direction. The frame 23 is rotatable in both directions about the second central axis O2. The cutter 25 is rotatable in both directions about the third central axis O3, but may be rotatable in one direction.

[0038] As shown in Figure 4, the shield tunneling machine 100 also has a control unit 50 that controls the operation of each component of the shield tunneling machine 100, a first angle sensor 52 (first detection unit) that measures the rotation angle of the rotating body 21 around the first axis O1, a second angle sensor 54 (second detection unit) that measures the rotation angle of the frame 23 around the second axis O2, a third angle sensor 56 (third detection unit) that measures the rotation angle of the cutter 25 relative to the third axis O3, and a load sensor 58 (load detection unit) that detects the load on the cutter 25.

[0039] The control unit 50 is configured by a computer including a CPU (Central Processing Unit) that executes a control program, a ROM (Read-Only Memory) that stores the control program executed by the CPU, a RAM (Random Access Memory) that stores the results of CPU calculations, and a communication device. The control unit 50 executes various functions of the control unit 50 described in this specification by loading the control program stored in the ROM into the RAM and executing it on the RAM by the CPU. The control unit 50 may be configured by a single computer, or may be configured by multiple microcomputers and configured to perform each control in a distributed manner among the multiple computers. The control unit 50 is configured to, for example, receive an operator's operation input from an input device (not shown) and output predetermined information to a display device (not shown) to display the information.

[0040] The control unit 50 controls the drive of the jack 15 to control the extension speed (extension amount per unit time) of the jack 15 and, in turn, the forward movement speed (excavation speed) of the excavation unit 20. The control unit 50 also controls the rotation speed of the auger 42 of the screw conveyor 40 and the opening degree of the gate 43 to control the amount of earth and sand discharged by the screw conveyor 40.

[0041] The control unit 50 also controls the operation of the first drive means 30 and the second drive means 32 based on the measurement results of the first angle sensor 52 and the second angle sensor 54, thereby controlling the cutter 25 to be at a desired position. The control unit 50 controls the operation of the first drive means 30, the second drive means 32, and the third drive means 34 so that the cutter 25 moves along a predetermined trajectory (excavation trajectory) and speed in a cross section perpendicular to the axis of the tunnel T. In other words, by controlling the rotation of the rotor 21 about the first axis O1 and the rotation of the frame 23 about the second axis O2, the position (angular position) of the cutter 25 relative to the first axis O1 is controlled to be the desired one (trajectory and speed). More specifically, as will be described later, the third axis O3 of the cutter 25 is controlled to be at a predetermined trajectory (excavation trajectory) and speed.

[0042] The load sensor 58 measures the excavation load of the cutter 25, which rotates (revolves) around the first axis O1 and rotates (spins) around the third axis O3. The load sensor 58 may be, for example, a load cell that directly measures the load acting on the cutter 25, a torque sensor that measures the load of the electric motor 35 that rotationally drives the cutter 25, a voltmeter, or an ammeter. If the third drive means 34 that rotationally drives the cutter 25 has a hydraulic motor, the load sensor 58 may be a pressure sensor that measures the load pressure of the hydraulic motor.

[0043] Next, we will explain the tunnel excavation method using the shield machine 100. The tunnel excavation method of this embodiment includes a step of excavating the natural ground to form the excavation hole 1 (natural ground excavation step), a step of identifying the position of an obstacle Ob within the excavation cross section based on the position of the third axis O3 within the excavation cross section acquired from the detection results of the first angle sensor 52 and the second angle sensor 54 and the load on the cutter 25 rotating around the third axis O3 detected by the load sensor 58 (obstacle detection step), and a step of excavating the obstacle Ob whose position has been identified (obstacle cutting step).

[0044] [Ground excavation process] The natural ground excavation process is carried out by the control unit 50 controlling each component of the shield tunneling machine 100, including the excavation unit 20. The control unit 50 is pre-programmed so as to be able to carry out the following natural ground excavation process.

[0045] The relative distance of cutter 25 (third axis O3) to first axis O1, i.e., the distance (orbital radius) of cutter 25 to third axis O3 from first axis O1, changes depending on the rotation angle of frame 23 with respect to second axis O2. In shield machine 100, by controlling the angular position of cutter 25 with respect to first axis O1, it is possible to move cutter 25 along a non-circular trajectory such as a rectangle (square, oblong), ellipse, oval, or horseshoe shape, and to excavate tunnel T with a non-circular cross section (see FIG. 2, for example).

[0046] In the shield machine 100, even if the cutter 25 moves along a rectangular trajectory, the rotating cutter 25 will cause the corners of the rectangular cross section of the tunnel T to be rounded. Furthermore, because the cutter 25 is subjected to reaction forces from the excavating face, it is difficult to drive it along a perfectly rectangular trajectory. Terms used in this specification that indicate shapes, such as rectangle (square, oblong), ellipse, oval, and horseshoe, are not used in their strict sense, and errors and deviations are permitted within the scope of the technical concept of the present invention.

[0047] For ease of explanation, a Cartesian coordinate system is set up, with the first axis O1 as the origin and two orthogonal axes extending horizontally and vertically, as shown in Fig. 5. That is, the horizontal axis in the Cartesian coordinate system is formed by a horizontal axis line that passes through the first axis O1 and extends horizontally, and the vertical axis is formed by a vertical axis line that passes through the first axis O1 and extends horizontally. The configuration of the rotor 21, frame 23, and cutter 25 can be approximated by a two-link mechanism (model) having a first link 60 and a second link 61 in the Cartesian coordinate system.

[0048] The first link 60 has one end corresponding to the first axis O1 as a rotation fulcrum and has a length L1 corresponding to the radius of rotation of the second axis O2 relative to the first axis O1 (the distance between the first axis O1 and the second axis O2). The second link 61 is rotatably connected to the first link 60 with the other end of the first link 60 as a rotation fulcrum and has a length L2 corresponding to the radius of rotation of the third axis O3 relative to the second axis O2 (the distance between the second axis O2 and the third axis O3). The end of the second link 61 opposite to the end connected to the first link 60 corresponds to the cutter 25 (the third axis O3).

[0049] The rotation angle θ1 of the first link 60 and the rotation angle θ2 of the second link 61 for setting the position P(x, y) of the center of the cutter 25 (third axis O3) relative to the first axis O1 to a desired position (trajectory) are obtained by the following equations (1) and (2) as an inverse motion problem of a two-link model. Note that, hereinafter, the position P of the center of the cutter 25 will also be simply referred to as "position P of the cutter 25."

[0050]

number

[0051] The control unit 50 stores the rotation angles θ1 and θ2 (rotation angles of the rotor 21 and frame 23) of the first link 60 and the second link 61 that position P of the cutter 25 to achieve the desired excavation cross section (desired excavation trajectory). The control unit 50 controls the operation of the first drive means 30 and the second drive means 32 so that the rotation angles are achieved. This allows the shield machine 100 to excavate a tunnel T with a non-circular cross section corresponding to the non-circular excavation trajectory of the cutter 25. FIG. 6(a) shows the excavation trajectory of the third axis O3, which is the center of the cutter 25, as viewed from the axial direction of the tunnel T. As the center of the cutter 25 (third axis O3) moves along the excavation trajectory shown in FIG. 6(a), i.e., rotates, the cutter bit (not shown) attached to the rotor 21 or the cutter 25 excavates the entire area of ​​the tunnel T with the non-circular excavation cross section. The symbol 1a in Figure 6(a) indicates the boundary between the excavation area excavated by the cutter 25 and the other non-excavation area, and indicates the outer edge of the excavation cross section formed by the cutter 25 (hereinafter also referred to as the "outer edge 1a of the excavation cross section").

[0052] That is, as the cutter 25 moves along the excavation trajectory, the outer edge of the cutter 25 forms a boundary between the excavation area and the non-excavation area. Then, a cutter bit (not shown) and the cutter 25 excavate the natural ground, forming a non-circular excavation cross section (outer edge 1a). Furthermore, for example, the outer edge 1a of the excavation cross section formed by the outer edge of the cutter 25 moving while rotating approximately coincides with the outer periphery of the tip of the skin plate 11 when viewed from the axial direction of the tunnel T (in other words, the projection line L1 of the outer periphery of the tip of the skin plate 11 onto the cross section perpendicular to the tunnel T). More preferably, as shown in FIG. 6(b), the outer edge 1a of the excavation cross section formed by the cutter 25 is set in a range of 0 mm to 50 mm radially outward from the projection line L1 of the outer periphery of the tip of the skin plate 11 onto the cross section perpendicular to the axis of the tunnel T. In other words, the outer edge 1a of the excavation cross section by the cutter 25 is set to be located between a projection line L1 of the outer periphery of the tip of the skin plate 11 and a virtual line L2 that is spaced radially outward from the projection line L1 by a distance G (= 50 mm).

[0053] [Obstacle detection process] The obstacle detection process is a process of detecting whether an obstacle Ob exists in the excavation cross section excavated by the cutter 25. For example, the obstacle detection process is executed in parallel with the execution of the natural ground excavation process. The control unit 50 is programmed to be able to execute the following obstacle detection process.

[0054] The obstacle detection process is a process of identifying the position of an obstacle Ob within the excavation cross section based on the position P of the cutter 25 within the excavation cross section obtained from the detection results of the first angle sensor 52 and the second angle sensor 54, and the load of the cutter 25 detected by the load sensor 58.

[0055] The rotational position of the second axis O2 detected by the first angle sensor 52 (in other words, the rotation angle of the rotor 21 relative to the first axis O1) corresponds to the rotation angle θ1 in equation (1). The rotational position of the third axis O3 (cutter 25) detected by the second angle sensor 54 (in other words, the rotation angle of the frame 23 relative to the second axis O2) corresponds to the rotation angle θ2 in equation (2). Therefore, the position of the cutter 25 can be obtained based on equations (1) and (2) from the detection results of the first angle sensor 52 and the second angle sensor 54. In addition, the detection result by the load sensor 58 is input to the control unit 50. The control unit 50 stores the position of the cutter 25 and the load in association with each other.

[0056] The control unit 50 detects contact between the cutter 25 and an obstacle Ob based on the acquired load on the cutter 25. For example, the control unit 50 can detect contact between the cutter 25 and an obstacle Ob by comparing the load on the cutter 25 with a load threshold value that is set and stored in advance. When the cutter 25 comes into contact with an obstacle Ob buried underground and attempts to excavate, the load acting on the cutter 25 increases due to the obstacle Ob, which is stronger than the natural soil. Therefore, the position of the obstacle Ob can be detected by a load sensor 58 that detects the load acting on the cutter 25.

[0057] In this way, the control unit 50 acquires the current position of the cutter 25, the load on the cutter 25 at that time, contact between the cutter 25 and the obstacle Ob (in other words, whether or not there is an obstacle Ob within the excavation cross section), and the position at which the cutter 25 comes into contact with the obstacle Ob (in other words, the position of the obstacle Ob within the excavation cross section).

[0058] Information about the load and position of the cutter 25 and contact with the obstacle Ob (the position of the obstacle Ob) is sent from the control unit 50 to a display unit, for example, and displayed on a display device so that the operator can recognize it.

[0059] [Obstacle removal process] The obstacle cutting process is a process in which an operation is performed to cut the obstacle Ob efficiently and appropriately, which differs from the operation of cutter 25 in the natural ground excavation process. The obstacle cutting process may be performed by control (automatic control) of the configuration of shield tunneling machine 100 by control unit 50, or may be performed by an operator operating (manual control) the configuration of shield tunneling machine 100 based on information obtained in the obstacle exploration process.

[0060] The obstacle cutting process of this embodiment includes at least one of an inner trajectory cutting process in which the cutter 25 is moved along an inner trajectory that passes inside the excavation trajectory of the cutter 25 in the natural ground excavation process to cut the obstacle Ob; a deceleration cutting process in which the forward speed of the excavation section 20 is reduced and the amount of soil discharged from the screw conveyor 40 is reduced to cut the obstacle Ob; a reciprocating cutting process in which the cutter 25 is moved back and forth within a predetermined range of the excavation cross section that includes the position of the obstacle Ob to cut the obstacle Ob; and a lateral cutting process in which the obstacle Ob is cut by the lateral excavation section 25b of the cutter 25.

[0061] [Inner trajectory cutting process] In the inside trajectory cutting process, the obstacle Ob is cut along an inside trajectory in which the cutter 25 moves mainly through the portion of the excavation cross section where the obstacle Ob is present, avoiding the portion where the obstacle Ob is not present. Specifically, as shown in FIG. 6(a), the inside trajectory is a trajectory in which at least a portion passes inside (on the first axis O1 side of) the excavation trajectory relative to the first axis O1 on the excavation cross section, and the cutter 25 moving along the inside trajectory comes into contact with the obstacle Ob. Note that in FIG. 6(a), the moving cutter 25 is schematically shown by a dashed line. The inside trajectory may be non-circular or may be circular.

[0062] As described above, when the outer edge 1a of the excavation cross section formed by the cutter 25 moving along the excavation locus is set so as to approximately coincide with the projection line L1 of the outer periphery of the end of the skin plate 11 as viewed from the axial direction of the tunnel T, the inner locus is set so that at least a portion of it passes inside the excavation locus. In other words, the inner locus is set so that, when viewed from the axial direction of the tunnel T, the projection line of the path (locus) along which the outer edge (outer periphery) of the cutter 25 passes passes radially inward of the projection line L1 of the outer periphery of the end of the skin plate 11. Similarly, when the outer edge 1a of the excavation cross section formed by the cutter 25 moving along the excavation locus is set in a range of 0 mm to 50 mm radially outward of the projection line L1 of the outer periphery of the end of the skin plate 11 as viewed from the axial direction of the tunnel T, the inner locus is set so that at least a portion of it passes inside the excavation locus. In other words, the inner trajectory is set so that, when viewed from the axial direction of the tunnel T, the projection line of the path passed by the outer edge of the cutter 25 (for example, line L3 shown in Figure 6(b)) passes inside the outer edge 1a of the excavation cross section, which is set in a range of 0 mm to 50 mm outside the projection line L1 of the outer periphery of the end of the skin plate 11.

[0063] The cutter 25 may be operated by an operator's operation input so as to move along the inner trajectory, or may be controlled by the control unit 50 so as to move along the inner trajectory.

[0064] For example, when an operator visually checks the positions of the cutter 25 and the obstacle Ob on the display device and moves the cutter 25 so that it comes into contact with the obstacle Ob, the cutter 25 naturally moves along the inner trajectory and the obstacle Ob is cut by the cutter 25.

[0065] The inner trajectory may be set by the control unit 50 using a predetermined algorithm from the position of the obstacle Ob acquired in the obstacle detection process, or may be set by the operator from the position of the obstacle Ob. In this way, the control unit 50 controls the cutter 25 to move along the predetermined inner trajectory, thereby automatically cutting the obstacle Ob.

[0066] [Deceleration cutting process] In the deceleration cutting process, when an obstacle Ob is detected, the forward speed of the excavation unit 20 (extension speed of the jack 15) is reduced, and the rotational speed of the auger 42 in the screw conveyor 40 is reduced and / or the opening of the gate 43 is reduced, thereby reducing the amount of earth and sand discharged by the screw conveyor 40. This reduces the forward speed of the excavation unit 20 and reduces the amount of ground excavated, while preventing a drop in pressure in the cutter chamber and stabilizing earth pressure at the face. Note that in the deceleration cutting process, the forward speed of the excavation unit 20 (extension speed of the jack 15) may be stopped, and the rotation of the auger 42 in the screw conveyor 40 may be stopped and / or the gate 43 may be closed.

[0067] The cutter 25 is brought into contact with the obstacle Ob while the forward speed of the excavation unit 20 is reduced, thereby cutting the obstacle Ob. The movement of the cutter 25 at this time may be automatically controlled by the control unit 50 or may be manually operated by an operator. The movement of the cutter 25 may be along an excavation trajectory in the natural ground excavation process, or may be in some other way.

[0068] By reducing the forward movement speed of the excavation unit 20 compared to the natural ground excavation process, the corresponding workload can be allocated to cutting the obstacle Ob. Therefore, a larger load (excavation force) can be exerted by the cutter 25, and the obstacle Ob can be cut more efficiently.

[0069] [Reciprocating cutting process] In the reciprocating cutting process, when an obstacle Ob is detected, a predetermined cutting range including the position of the obstacle Ob is set on the excavation cross section. The cutting range indicates a part of the excavation cross section. The cutting range may be set by the control unit 50 using a predetermined algorithm based on the position of the obstacle Ob, or may be set manually by the operator.

[0070] Then, the cutter 25 is moved to a position within the set cutting range, and the cutter 25 is moved so as to reciprocate within the cutting range (arrow in FIG. 7). The reciprocation of the cutter 25 here refers to the direction of movement relative to the first axis O1, and in FIG. 7, this includes both movement in the clockwise direction and movement in the counterclockwise direction. The movement of the cutter 25 may be automatically controlled by the control unit 50, or may be controlled by operation by the operator. In FIG. 7, the moving cutter 25 is schematically shown by a dashed line.

[0071] By reciprocating the cutter 25 in the cutting range in this manner, only the cutting range is excavated without excavating the range where the obstacle Ob does not exist on the excavation cross section, so that the obstacle Ob can be excavated efficiently.

[0072] [Side cutting process] In the side cutting process, when an obstacle Ob is detected, as shown in FIG. 8(a), the cutter 25 is first moved to an area of ​​the excavation cross section where the obstacle Ob does not exist. For example, as shown in FIG. 8(a), the cutter 25 is preferably moved downward relative to the obstacle Ob. Next, in this state, the excavation unit 20 is slightly advanced to excavate the natural ground, and then the advancement of the excavation unit 20 is stopped or decelerated. In this state, the obstacle Ob and the side excavation unit 25b of the cutter 25 are positioned so that they overlap in a cross section perpendicular to the first axis O1 (see FIG. 8(b)). Preferably, they are positioned so that they are located in the same cross section. Then, the cutter 25 is moved toward the obstacle Ob in the cross section (see the arrow in FIG. 8(b)), so that the side excavation unit 25b of the cutter 25 comes into contact with the obstacle Ob, and the side excavation unit 25b cuts the obstacle Ob. By stopping or slowing down the forward movement of the excavation unit 20, the amount of excavated soil taken into the cutter chamber 14 by excavating new ground is reduced or significantly reduced. This makes it possible to suppress volumetric changes within the cutter chamber 14 and to suppress fluctuations in earth pressure within the cutter chamber 14.

[0073] When the obstacle Ob is cut by the front excavation section 25a and the side excavation section 25b of the advancing cutter 25, not only the obstacle Ob but also the natural ground corresponding to the area of ​​the cutter 25 is excavated, which increases the load on the cutter 25. In other words, when the obstacle Ob is cut by the advancing cutter 25, the workload of the cutter 25 includes not only the cutting of the obstacle Ob but also the excavation of the natural ground. In contrast, in the side cutting process, the excavation section 20 is moved forward slightly at a position on the excavation cross section where the obstacle Ob does not exist, to excavate the natural ground in advance, and then the obstacle Ob is cut by the side excavation section 25b of the cutter 25 moving in a cross section perpendicular to the first axis O1. As a result, the amount of natural ground excavated together with the obstacle Ob is relatively small. Furthermore, as the cutter 25 moves in a direction perpendicular to the first axis O1, it contacts the obstacle Ob and the natural ground not only at its front but also at a portion of its circumferential direction. This results in a relatively smaller contact area of ​​the cutter 25 compared to when it moves in a direction parallel to the first axis O1 (advancing toward the natural ground). This allows a greater excavation force to be applied to the obstacle Ob, in other words, a greater workload to be allocated to cutting the obstacle Ob, enabling the obstacle Ob to be cut efficiently. Cutting the obstacle Ob from the tunnel cross-sectional end (one end) using the side excavation section 25b of the cutter 25 reduces the impact on the surrounding natural ground and improves cutting efficiency. In particular, for an obstacle Ob extending underground, positioning the cutter 25 below the obstacle Ob and cutting the obstacle Ob from its lower end reduces the impact on the surrounding natural ground associated with cutting the obstacle Ob and improves cutting efficiency. In addition, the cutter 25 is formed in a dome shape by the front excavation section 25a and the side excavation section 25b, and the obstacle Ob is cut by the side excavation section 25b, so that the obstacle Ob can be cut continuously little by little while ensuring support for it through a relatively small contact area.

[0074] If the advance speed of the excavation unit 20 is relatively low, it is not necessary to stop or slow down the advance of the excavation unit 20 after the cutter 25 has been moved and advanced to an area where no obstacle Ob exists.

[0075] As described above, the obstacle cutting process includes at least one of the inside cutting process, the reciprocating cutting process, the deceleration cutting process, and the side cutting process. Note that the obstacle cutting process may be configured to include some (two or three) or all of the four cutting processes (e.g., multiple processes are performed sequentially). Also, for example, the deceleration cutting process may be performed simultaneously with any of the other three processes.

[0076] According to the above embodiment, the following advantageous effects are achieved.

[0077] The shield machine 100 comprises a skin plate 11 capable of supporting the inner wall of the natural ground, and an excavation unit 20 attached to the skin plate 11 and excavating the natural ground. The excavation unit 20 comprises a rotor 21 configured to be rotatable about a first axis O1 parallel to the axis of the tunnel T, a first drive means 30 for rotating the rotor 21 about the first axis O1, and a frame 2 supported by the rotor 21 to be rotatable about a second axis O2 parallel to the first axis O1 and spaced apart from the first axis O1. The shield machine 100 includes a shield shaft 33, a second drive means 32 that rotates the frame 23 about the second axis O2, a cutter 25 supported by the frame 23 to be rotatable about a third axis O3 that is parallel to the second axis O2 and spaced apart from the second axis O2, a first angle sensor 52 that detects the rotational position of the second axis O2 relative to the first axis O1, a second angle sensor 54 that detects the rotational position of the third axis O3 relative to the second axis O2, and a load sensor 58 that detects the load on the cutter 25. The tunnel excavation method using the shield machine 100 includes the steps of: identifying the position of an obstacle Ob within the excavation cross section based on the position of the third axis O3 within the excavation cross section obtained from the detection results of the first angle sensor 52 and the second angle sensor 54, and the load on the cutter 25 rotating about the third axis O3 detected by the load sensor 58; and excavating the obstacle Ob whose position has been identified. In addition, the control unit 50 of the shield tunneling machine 100 determines the position of the obstacle Ob within the excavation cross section based on the position of the third axis O3 within the excavation cross section obtained from the detection results of the first angle sensor 52 and the second angle sensor 54, and the load of the cutter 25 rotating around the third axis O3 detected by the load sensor 58.

[0078] The tunnel excavation method also includes a step of excavating the ground by moving the cutter 25 along an excavation trajectory whose outer edge forms a non-circular excavation cross section, and a step of cutting an obstacle Ob within the excavation cross section, and in the step of cutting the obstacle Ob, the cutter 25 is moved along an inner trajectory at least a portion of which passes inside the excavation trajectory to cut the obstacle Ob.

[0079] The shield machine 100 also includes a jack 15 that advances the excavation section 20 toward the natural ground, a partition wall 13 that is provided within the skin plate 11 and that faces the excavation section 20 in the axial direction of the tunnel T, a cutter chamber 14 that is partitioned by the skin plate 11, the excavation section 20, and the partition wall 13 and into which the earth and sand excavated by the excavation section 20 flows, and a screw conveyor 40 that takes out and discharges the earth and sand from the cutter chamber 14. In the step of cutting the obstacle Ob in the tunnel excavation method, when the position of the obstacle Ob is identified, the forward movement speed of the excavation section 20 is reduced and the rate of earth and sand discharged by the screw conveyor 40 is also reduced, thereby cutting the located obstacle Ob.

[0080] The tunnel excavation method also includes a step of cutting the obstacle Ob by reciprocating the cutter 25 within a predetermined range of the excavation cross section that includes the position of the obstacle Ob.

[0081] Furthermore, in the shield machine 100, the cutter 25 has a front excavation section 25a that can excavate the front surface in the direction of travel, which is a surface perpendicular to the first axis O1, and side excavation sections 25b that are provided around the front excavation section 25a with respect to the first axis O1 and that can excavate an inclined surface that is inclined relative to the front surface in the direction of travel. The tunnel excavation method includes a step of cutting the obstacle Ob with the side excavation section 25b of the cutter 25.

[0082] In the above-described embodiment, the position of the obstacle Ob is identified based on the position of the third axis O3 (cutter 25) and the excavation load of the cutter 25. Therefore, the obstacle Ob can be appropriately cut by moving the cutter 25 to the identified position of the obstacle Ob and operating it to cut the obstacle Ob. Specifically, the obstacle Ob can be appropriately cut by performing an operation of cutting the obstacle Ob by moving the cutter 25 along an inner trajectory that passes inside the excavation trajectory along which the cutter 25 excavates the excavation cross section (inner trajectory cutting process), an operation of moving the cutter 25 to the position of the obstacle Ob and reciprocating it within a predetermined range that includes the obstacle Ob (reciprocating cutting process), an operation of cutting the obstacle Ob by the cutter 25 by reducing the forward speed of the jack 15 and the discharge speed of the soil and sand by the screw conveyor 40 (basic cutting process), and an operation of cutting the obstacle Ob by the side excavation section 25b (side cutting process).

[0083] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments. [Explanation of symbols]

[0084] 11 Skin Plate (torso) 13 Bulkhead 14 Cutter chamber 15 Jack (propulsion device) 20 Excavation Section 21 Rotating body (first member) 23 Frame (second member) 25 Cutter 25a Front excavation section 25b Side excavation section 30 First driving means 32 second driving means 40 Screw conveyor (discharge mechanism) 50 control section 52 first angle sensor (first detection unit) 54 Second angle sensor (second detection unit) 58 Load sensor (load detection section) 100 Shield tunneling machine (tunnel boring machine)

Claims

1. a trunk capable of supporting the inner wall of the natural ground; a tunnel excavation unit attached to the body and configured to excavate the natural ground, The excavation section is a first member configured to be rotatable about a first axis parallel to the axis of the tunnel; a first driving means for rotating the first member about the first axis; a second member supported by the first member so as to be rotatable about a second axis parallel to the first axis and spaced apart from the first axis; second driving means for rotating the second member about the second axis; a cutter supported by the second member so as to be rotatable about a third axis parallel to the second axis and spaced apart from the second axis; a third driving means for rotating the cutter about the third axis; a first detection unit that detects a rotational position of the second axis relative to the first axis; a second detection unit that detects a rotational position of the third axis relative to the second axis; a load detection unit that detects the load on the cutter, The tunnel excavation method includes: A process of identifying the position of an obstacle within the excavation cross section based on the position of the third axis within the excavation cross section obtained from the detection results of the first detection unit and the second detection unit and the load of the cutter rotating around the third axis detected by the load detection unit; and excavating the located obstruction. Tunnel excavation methods.

2. a trunk capable of supporting the inner wall of the natural ground; a tunnel excavation unit attached to the body and configured to excavate the natural ground, The excavation section is a first member configured to be rotatable about a first axis parallel to the axis of the tunnel; a first driving means for rotating the first member about the first axis; a second member supported by the first member so as to be rotatable about a second axis parallel to the first axis and spaced apart from the first axis; second driving means for rotating the second member about the second axis; a cutter supported by the second member so as to be rotatable about a third axis that is parallel to the second axis and spaced apart from the second axis, The tunnel excavation method includes: a step of excavating the natural ground by moving the cutter along an excavation trajectory whose outer edge forms a non-circular excavation cross section; and cutting away obstacles in the excavation cross section, In the step of cutting the obstacle, the cutter is moved along an inner trajectory, at least a portion of which passes inside the excavation trajectory, to cut the obstacle. Tunnel excavation methods.

3. 3. A tunnel excavation method according to claim 1 or 2, The tunnel boring machine a propulsion device that advances the excavation unit toward the natural ground; A partition wall provided within the body and arranged opposite the excavated portion in the axial direction of the tunnel; a cutter chamber partitioned by the body and the partition wall and into which earth and sand excavated by the excavation unit flows; a discharge mechanism for removing and discharging soil and sand from the cutter chamber, In the step of cutting the obstacle, when the position of the obstacle is identified, the forward movement speed of the excavation unit is reduced and the amount of earth and sand discharged by the discharge mechanism is reduced, thereby cutting the obstacle. Tunnel excavation methods.

4. 3. A tunnel excavation method according to claim 1 or 2, a step of reciprocating the cutter within a predetermined range of the excavation cross section including the position of the obstacle to cut the obstacle; Tunnel excavation methods.

5. 3. A tunnel excavation method according to claim 1 or 2, The cutter is A front excavation unit capable of excavating a front surface in the traveling direction, which is a surface perpendicular to the first axis; A side excavation section is provided around the front excavation section with respect to the first axis and is capable of excavating an inclined surface inclined with respect to the front surface in the traveling direction, The tunnel excavation method includes: cutting the obstacle with the side digging portion of the cutter; Tunnel excavation methods.

6. A tunnel boring machine for excavating a tunnel, a trunk capable of supporting the inner wall of the natural ground; an excavation unit attached to the body and configured to excavate the natural ground; a control unit that controls the operation of the excavation unit, The excavation section is a first member configured to be rotatable about a first axis parallel to the axis of the tunnel; a first driving means for rotating the first member about the first axis; a second member supported by the first member so as to be rotatable about a second axis parallel to the first axis and spaced apart from the first axis; second driving means for rotating the second member about the second axis; a cutter supported by the second member so as to be rotatable about a third axis parallel to the second axis and spaced apart from the second axis; a third driving means for rotating the cutter about the third axis; a first detection unit that detects a rotational position of the second axis relative to the first axis; a second detection unit that detects a rotational position of the third axis relative to the second axis; a load detection unit that detects the load on the cutter, The control unit identifying a position of an obstacle within the excavation cross section based on the position of the third axis within the excavation cross section obtained from the detection results of the first detection unit and the second detection unit and the load of the cutter rotating around the third axis detected by the load detection unit; Tunnel boring machine.

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