JP6571485B2 - Tunnel excavation method and tunnel excavation apparatus - Google Patents

Description

  The present invention relates to a tunnel excavation method and a tunnel excavation apparatus for excavating a tunnel in the ground.

  Conventionally, in the TBM method using a tunnel boring machine (TBM), the ground is excavated by the TBM, and a support for supporting the ground behind the TBM is constructed. As such a support work, a reinforced concrete liner (RC liner) is widely used in order to ensure a stable construction speed. The RC liner support is constructed by connecting a plurality of RC liners formed in an arc cross-section in a circumferential direction along the inner wall of a tunnel excavated by TBM, and connected in an annular shape. It is integrated with the ground by filling back mortar between the wall and the tunnel inner wall. And, in a space where the thrust reaction force by the gripper cannot be sufficiently secured, the TBM can push the reaction force against the support work by the RC liner integrated with the ground.

Japanese Patent Laid-Open No. 11-2095

  However, in the case of adopting such RC liner support, the volume of the space between the tunnel inner wall and the RC liner is very large, and a large amount of back-filling mortar is required, leading to high costs. End up. In order to reduce the amount of backfill mortar, cobblestones and crushed stones are also introduced between the RC liner and the inner wall of the tunnel. By adding this cobblestone and crushed stones, tunnel excavation is possible. The speed will drop.

  The present invention has been made in view of the above problems, and the purpose of the present invention is to reduce the cost without reducing the tunnel excavation speed even when a liner-type support is used. It is to provide a drilling method.

  The tunnel excavation method of the present invention includes an apparatus main body, a cutter head that is provided at the front end of the apparatus main body and is rotatable with respect to the apparatus main body, and a cylindrical member that surrounds the rear end of the apparatus main body and extends rearward of the apparatus main body. And a tunnel excavation method using a tunnel excavation device comprising: a first excavation step for excavating the ground by rotating a cutter head relative to the apparatus main body; and a device advance step for advancing the tunnel excavation device; And a liner assembling step for annularly assembling the liner in the tubular member so as to be continuous with the front end portion of the liner supporting work already constructed.

  Conventionally, since the liner is assembled in the space inside the apparatus main body, only a liner supporting work having an outer diameter smaller than the inner diameter of the apparatus main body can be constructed. On the other hand, according to the present invention having the above-described configuration, the liner is assembled in an annular shape in a cylindrical member that surrounds the rear end portion of the excavator and extends rearward of the apparatus main body. A liner support having an outer diameter can be constructed. Thereby, the volume of the space between the liner assembled in an annular shape and the wall surface of the ground excavated by the cutter head can be reduced, and the amount of filler filled in this space can be reduced. Thus, the amount of filler can be reduced without introducing cobblestone or the like between the liner and the inner wall of the tunnel, so that the cost can be reduced without reducing the tunnel excavation speed.

  In the present invention, preferably, the cutter head has an annular shape, and in the first excavation step, the ground is excavated in an annular shape, and an inner portion excavated in an annular shape of the ground is excavated in the apparatus main body. 2 drilling steps.

  According to the present invention having the above-described configuration, the ground is excavated in an annular shape in advance by an annular cutter head, and the inner portion excavated in an annular shape in parallel with this is excavated in the apparatus body. The excavation speed can be improved.

  In the present invention, preferably, the method further comprises a backfill injection step for injecting a filler into an annular cross-section space between the ground wall excavated by the cutter head and the liner assembled in an annular shape, and the backfill injection step Includes a first injection step of injecting a filler into a portion of the annular cross-section space below a predetermined height, and a second injection of injecting the filler into a portion above the predetermined height of the annular cross-section space. And a process.

  The excavated soil generated by excavating the ground enters the lower part between the ring-assembled liner and the ground wall excavated by the cutter head, and the tunnel excavator passes above the excavated soil. So it is compacted. For this reason, the liner can be integrated with the ground only by injecting a small amount of filler in the first injection step.

In the present invention, the tunnel excavator preferably has a jack that can be extended rearward at a lower part of the rear of the apparatus.
As described above, the lower part of the assembled liner is integrated with the ground prior to the first injection step. For this reason, according to this invention of the said structure, since a reaction force can be taken with the jack at the lower part of a liner, the ground can be excavated in the state which pressed the cutter head against the ground with a stronger force.

The tunnel excavation apparatus of the present invention is a tunnel excavation apparatus for excavating the ground, the apparatus main body, a cutter head provided at the tip of the apparatus main body and excavating the ground by rotating with respect to the apparatus main body, And a cylindrical member that surrounds the rear end portion of the apparatus main body, extends to the rear of the apparatus main body, and in which an assembly operation for assembling the liner in an annular shape is performed.
In the present invention, the cutter head is preferably annular and excavates the ground in an annular shape.

  According to the present invention, even when a liner-type support is used, the cost can be reduced without reducing the tunnel excavation speed.

1 is a perspective view showing a tunnel excavation device according to an embodiment of the present invention. It is a longitudinal direction vertical sectional view showing a tunnel excavation device according to an embodiment of the present invention. It is III-III sectional drawing in FIG. It is a front view which shows the tunnel excavation apparatus by one Embodiment of this invention. It is VV sectional drawing in FIG. It is VI-VI sectional drawing in FIG. It is VII-VII sectional drawing in FIG. It is a figure for demonstrating the propulsion method of a drilling apparatus, and the assembly operation of a liner. It is a figure for demonstrating the method of implementing backfilling injection | pouring operation | work.

Hereinafter, an embodiment of a tunnel excavation system and a tunnel excavation method of the present invention will be described in detail with reference to the drawings.
1 to 7 show a tunnel excavation device according to an embodiment of the present invention. FIG. 1 is a perspective view, FIG. 2 is a longitudinal vertical sectional view, FIG. 3 is a sectional view taken along III-III in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2, FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 2, and FIG. 7 is a cross-sectional view taken along line VII-VII in FIG.

  As shown in FIGS. 1 and 2, the excavator 10 excavates the ground with a cylindrical shell 12, a drilling mechanism 14 provided at the tip of the shell 12 in the direction of excavation (hereinafter referred to as the front), and the ground. The excavation soil carry-out mechanism 16 for carrying out the excavated soil generated in this manner and the propulsion mechanism 18 for propelling the excavation mechanism 14 are provided.

  The shell 12 is composed of a rotating part shell 20, a first fixed part shell 22, a second fixed part shell 24, and a third fixed part shell 26 that are sequentially connected from the front. The

  The rotating portion shell 20 includes an annular tip surface portion 20A that forms a tip surface, a cylindrical outer cylinder 20B that extends rearward from the outer periphery of the tip surface portion 20A, and a cylinder that extends rearward from the inner periphery of the tip surface portion 20A. A cylindrical inner cylinder 20C.

  Further, the first fixed part shell 22, the second fixed part shell 24, and the third fixed part shell 26 have substantially the same diameter as the outer cylindrical body 20B of the rotating part shell 20, respectively. The formed cylindrical outer cylinders 22B, 24B, and 26B and the outer cylinders 22B, 24B, and 26B are arranged to have a larger diameter than the inner cylinder 20C of the first fixed portion shell 22. The cylindrical inner cylinders 22C, 24C, 26C, and a plurality of support members (not shown) provided to connect the inner cylinders 22C, 24C, 26C and the outer cylinders 22B, 24B, 26B. The These shells 20, 22, 24, and 26 are each made of steel. The first fixed portion is formed such that a gap 20D is formed between the rear end of the inner cylindrical body 20C of the rotating portion shell 20 and the front end of the inner cylindrical body 22C of the first fixed portion shell 22. The shell 22 terminates in front of the front end of the inner cylindrical body 22C.

  Inner cylinders 20C, 22C, 24C, 26C and outer cylinders constituting the rotary part shell 20, the first fixed part shell 22, the second fixed part shell 24, and the third fixed part shell 26 The bodies 20B, 22B, 24B, and 26B are arranged concentrically and coaxially with the rotation shaft of the cutter unit 30 that will be described in detail later, whereby the inner cylinders 20C, 22C, 24C, and 26C and the outer cylinders 20B, 22B, An annular space is formed between 24B and 26B. The support member is made of a rod-like or plate-like steel material, the number capable of supporting earth pressure acting on the outer cylinders 20B, 22B, 24B, 26B, with the central axis of the inner cylinders 20C, 22C, 24C, 26C as the center The inner cylinders 20C, 22C, 24C, and 26C and the outer cylinders 20B, 22B, 24B, and 26B are provided so as to radiate at appropriate intervals in the circumferential direction and the axial direction. The propulsion mechanism 18 is accommodated in an annular space between the inner cylinders 20C, 22C, 24C, and 26C and the outer cylinders 20B, 22B, 24B, and 26B.

  The rotating part shell 20 is rotatably connected to the first fixed part shell 22. Note that slipping can be improved by interposing a bearing or the like between the rotating portion shell 20 and the first fixed portion shell 22.

  Further, the front end portions of the inner cylindrical body 24C and the outer cylindrical body 24B of the second fixed portion shell body 24 are located between the inner cylindrical body 22C of the first fixed portion shell body 22 and the rear end portion of the outer cylindrical body 22B. It is housed in the space. With this configuration, the second fixed portion shell 24 is connected to the first fixed portion shell 22 so as to be slidable in the axial direction.

  Similarly, the front end portions of the inner cylinder body 26C and the outer cylinder body 26B of the third fixed portion shell body 26 are the rear end portions of the inner cylinder body 26C and the outer cylinder body 26B of the second fixed portion shell body 24, respectively. Is housed between. With this configuration, the third fixed portion shell 26 is connected to the second fixed portion shell 24 so as to be slidable in the axial direction. The connecting portion between the first fixed portion shell 22 and the second fixed portion shell 24 and the connecting portion between the second fixed portion shell 24 and the third fixed portion shell 26 are axially connected. A guide member for guiding the sliding may be provided.

  A cylindrical tubular member 110 is provided at the rear end of the third fixed portion shell 26 so as to extend rearward. The cylindrical member 110 is made of, for example, an iron plate having a thickness of 20 mm or more (22 mm in this embodiment). The cylindrical member 110 is fixed to the third fixed portion shell 26 in a state of surrounding the outer periphery of the rear end portion of the third fixed portion shell 26. As will be described later, an assembly operation for assembling the liner in an annular shape is performed inside the cylindrical member 110. The cylindrical member 110 may be formed with a slit extending in the axial direction. Moreover, the cylindrical member 110 may be configured by a plurality of members having an arc cross-sectional shape, and a gap may be provided between the members having a plurality of arc cross-sectional shapes.

  As shown in FIG. 1 and FIG. 2, the excavation mechanism 14 includes a cutter unit 30 including a plurality of drill bits formed in the tip surface portion 20 </ b> A of the rotating unit shell 20, and a first fixed unit shell 22. And a reduction gear 32 and a motor 34 arranged.

  As shown in FIGS. 1 and 4, a plurality of openings 36 are formed in the distal end surface portion 20 </ b> A of the rotating portion shell 20 at intervals in the circumferential direction, and a space 20 </ b> E inside the rotating portion shell 20 is formed outside. Are communicated with each other through the opening 36.

As shown in FIG. 4, the cutter unit 30 includes a plurality of roller bits 38 provided on the distal end surface portion 20A of the rotating portion shell 20 at intervals in the circumferential direction, and an edge of an opening 36 formed on the distal end surface portion 20A. And a drill bit 40 provided in the above.
As shown in FIG. 2, a pin rack 35 is attached to the rear end portion of the rotary shell 20 via a ring 33.

  As shown in FIG. 2, a speed reducer 32 is connected to the motor 34 disposed in the first fixed portion shell 22, and a pinion 37 is attached to the speed reducer 32. A pinion 37 attached to the speed reducer 32 meshes with a pin rack 35 attached to the rotating part shell 20. As a result, when the motor 34 rotates, the torque is amplified through the speed reducer 32 and transmitted to the rotating part shell 20, and the rotating part shell 20 is centered on the central axis. Rotates relative to the fixed shells 22, 24, 26.

  Each roller bit 38 is disposed at a different position in the radial direction. Thereby, when the rotary shell 20 rotates in the circumferential direction, the trajectory through which each roller bit 38 passes becomes a concentric circle having substantially equal intervals in the radial direction, and uniform excavation can be performed regardless of the diameter.

  Further, the drill bit 40 is formed of a bit having a sharp tip, and is excavated so that the cutting surface cut by the roller bit 38 is flattened by the rotation of the rotating shell 20.

  As shown in FIG. 7, the excavated soil carry-out mechanism 16 is provided in the space 20E inside the rotating part shell 20 so as to divide the space 20E in the rotating part shell 20 into a plurality of chambers 20F in the circumferential direction. The plurality of plate members 42 and the first fixing portion shell 22 are fixed to the front end portion of the inner cylindrical body 22C and attached so as to extend toward the rear end of the inner cylindrical body 20C of the rotating portion shell body 20. A closing plate 44 and a jet nozzle (not shown) provided on the surface of the front end face portion 20A of the rotary shell 20 so as to inject water toward the ground.

  Each plate member 42 has a tip connected to the back surface of the tip portion 20A of the rotating portion shell 20 where the drill bit 40 is attached. In the present embodiment, the plate member 42 is provided perpendicular to the distal end surface portion 20A. However, the present invention is not limited thereto, and the plate member 42 is provided so as to be inclined in the circumferential direction of the rotary shell 20 toward the rear. Also good. Thus, by providing the plate member 42 in the rotating part shell 20, the rigidity of the rotating part shell 20 can be improved.

  The closing plate 44 has a predetermined clearance 20D between the rear end of the inner cylinder 20C of the rotating part shell 20 and the front end of the inner cylinder 22C of the first fixed part shell 22 from the lowermost part in the circumferential direction. Are provided so as to close the portion up to the height (in this embodiment, portions of about 120 ° on both sides in the circumferential direction from the lowermost portion).

  As shown in FIGS. 2 to 4, the propulsion mechanism 18 includes a front axial jack 52, a rear axial jack 50, a front radial jack 54, a rear radial jack 56, and an auxiliary jack. And a propulsion jack 57.

  The front axial jack 52 is accommodated between the inner cylinders 22C and 24C and the outer cylinders 22B and 24B from the first fixed part shell 22 to the second fixed part shell 24, Is fixed to the support member of the first fixed part shell 22, and the rear end is fixed to the support member of the second fixed part shell 24.

  The rear axial jack 50 is accommodated between the inner cylinders 24C and 26C and the outer cylinders 24B and 26B from the second fixed part shell 24 to the third fixed part shell 26, Is fixed to the support member of the second fixed portion shell 24, and the rear end is fixed to the support member of the third fixed portion shell 26.

  A plurality of the front axial jacks 52 and the rear axial jacks 50 are provided at appropriate intervals in the circumferential direction so as not to interfere with other members.

  The front radial jack 54 is accommodated in the first fixed shell 22. The outer cylindrical body 22B of the first fixed portion shell 22 has an opening formed at a position corresponding to the front radial jack 54, and the front radial jack 54 extends radially outward from the excavator 10 through this opening. It can be expanded and contracted so as to protrude toward the direction.

  The rear radial jack 56 is accommodated in the third fixed shell 26. The outer cylinder body 26B of the third fixed portion shell body 26 is formed with an opening at a position corresponding to the rear radial jack 56, and the rear radial jack 56 passes through the opening from the radial outer side of the excavator 10. It can be expanded and contracted so as to protrude toward the direction.

The propulsion jack 57 is disposed so as to extend in the front-rear direction below the rear end portion of the excavator 10, and can extend and contract toward the rear of the excavator 10.
The front axial jack 52, the rear axial jack 50, the front radial jack 54, the rear radial jack 56, and the propulsion jack 57 are connected to a control device (not shown). The hydraulic pressure is supplied by the control device.

As shown in FIGS. 2 and 3, the excavation apparatus 10 includes an excavated soil receiving plate 100, a rock crusher 106, and a conveyor 81 as the excavated soil carry-out mechanism 16.
A gantry 70 is held horizontally at the rear of the inner space of the excavator 10.

  The excavated soil receiving plate 100 is a plate material that extends horizontally from the inner side of the rotating portion shell 20 toward the rear. The excavated earth receiving plate 100 is provided at a height equal to the lower end of the inner surface of the inner cylindrical body 20C of the rotating part shell 20, and the inner cylindrical body 20C of the rotating part shell 20 and the first fixed part shell 22 is provided. , 22C so that no gap is generated between them. The excavated earth receiving plate 100 is provided at a lower position than the gantry 70.

  The front end of the conveyor 81 is located below the rock crusher 106 and extends rearward. The lower part of the inner cylinders 22C, 24C, and 26C of the first fixed part shell 22, the second fixed part shell 24, and the third fixed part shell 26 is cut over a predetermined width, A conveyor 81 is disposed in the cut portion. The conveyor 81 extends rearward and is inclined obliquely upward at the rear portion of the excavator 10.

  The rock crusher 106 is a biaxial crusher having a screw-shaped crushing bit. As such a crusher, for example, a sizer manufactured by MMD can be used. The crusher 106 is arranged directly above the conveyor 81 so that the upper end of the front portion is connected to the rear end of the excavated soil receiving plate 100 and the rear end is located below the gantry 70.

Hereinafter, a method for constructing a tunnel by the tunnel excavation apparatus of the present embodiment will be described.
In the present embodiment, the ground is excavated in an annular shape by repeating the first excavation step for excavating the ground 72 in an annular cross section by the excavator 10 and the device advance step for advancing the excavator 10 in advance. To do. In parallel with this, a tunnel having a circular cross section is constructed by performing a second excavation step of excavating the remaining ground 72 in the center inside the excavator 10 with the breaker 62 in the excavator 10. To do.
In parallel with this, a liner assembling step for constructing the liner support by assembling the liner in an annular shape so as to be continuous with the front end of the liner support already constructed at the rear of the excavator 10; A backfill injection step is performed in which mortar is injected between the annularly assembled liner and the ground wall excavated by the excavator to integrate the liner support with the ground.

Hereinafter, a method for excavating the ground in an annular cross-section by the excavator 10 will be described.
First, a method for propelling the excavator 10 by the propulsion mechanism 18 will be described. The propulsion operation is performed while rotating the rotating part shell 20 with respect to the fixed part shells 22, 24, and 26 and discharging the excavated soil by the excavated soil carrying-out mechanism 16.

  FIG. 8 is a diagram for explaining the propulsion method of the excavator 10 and the liner assembling operation. In the figure, for the sake of explanation, the rear axial jack 50, the rear radial jack 56, and the propulsion jack 57 are shown in the same plane. In order to propel the excavator 10, first, the rear radial jack 56 is extended radially outward to press the surrounding ground ((A) in FIG. 8). Then, the rear axial jack 50 is extended in a state where the reaction force is applied to the surrounding ground by the rear radial jack 56 ((B) of FIG. 8). At this time, it is desirable to extend the propulsion jack 57 to take a reaction force on the already constructed liner support 120. Thereby, the rotating part shell 20, the first fixed part shell 22, and the second fixed part shell 24 are pushed forward with respect to the third fixed part shell 26. At this time, the rotating part shell 20 is rotated, so that the ground is excavated in an annular shape by the roller bit 38 and the drill bit 40.

  At this time, the direction of excavation of the excavator 10 can be adjusted by extending each of the front axial jacks 52 to a different length. That is, for example, by increasing the extension length of the front axial jack 52 positioned below the apparatus, compared to the extension length of the front axial jack 52 positioned above the apparatus, The first fixed part shell 22 can be directed obliquely upward with respect to the second fixed part shell 24.

  Next, the front radial jack 54 is extended outward in the radial direction to press the surrounding ground, and the rear radial jack 56 is contracted. Then, the rear axial jack 50 is contracted in a state where a reaction force is applied to the surrounding ground by the front radial jack 54 ((C) in FIG. 8). As a result, the third fixed part shell 26 is drawn toward the first fixed part shell 22 and the second fixed part shell 24. The excavator 10 can be advanced by repeating the above steps.

Along with the above propulsion work, the rotary shell 20 is rotated to excavate the ground, and excavated soil generated by excavation is sent to the rear of the apparatus.
That is, the motor 34 of the excavation mechanism 14 is rotated in a state where the cutter mechanism 30 of the rotating shell 20 is pressed against the ground by the propulsion mechanism 18. The rotational force of the motor 34 is transmitted to the speed reducer 32, the torque is amplified, and the rotating part shell 20 is rotated via the pinion 37 and the pin rack 35. When the rotating part shell 20 rotates, first, the ground is excavated in a sawtooth shape by the roller bit 38 of the cutter part 30, and the surface irregularities are scraped by the drill bit 40. Thereby, the ground can be excavated in an annular shape.

  The excavated soil produced by excavating the ground with the cutter unit 30 is agitated with the water sprayed from the jet nozzle, and the fluidity is improved. Then, the excavated soil is accommodated in the chamber 20F in the rotating part shell 20 through the opening 36 formed in the distal end surface part 20A of the rotating part shell 20. Then, the excavated soil accommodated in the chamber 20F is discharged from the gap 20D to the inner space of the excavator 10 (that is, the inner side of the inner cylinder 22C).

  At this time, the closing plate 44 causes the gap 20D between the rear end of the inner cylindrical body 20C of the rotating portion shell 20 and the front end of the inner cylindrical body 22C of the first fixed portion shell 22 to be maximized in the circumferential direction. Since the portion from the lower part to the predetermined height is closed, the excavated soil in the chamber 20F rotated to the predetermined height is discharged into the inner space of the inner cylinder. As a result, the excavated soil carried to the inside of the apparatus accumulates downward, and the rear end of the inner cylinder 20C of the rotating part shell 20 and the front end of the inner cylinder 22C of the first fixed part shell 22 It is possible to prevent the gap 20D between them from being closed.

  In parallel with the work of excavating the ground in an annular shape by the excavator 10, the ground 72 inside the portion excavated in an annular shape by the excavator 10 is excavated by the breaker 62.

Next, a method for conveying the excavated soil generated by excavating the ground to the excavation area behind the excavator 10 will be described.
As described above, when the ground is excavated in an annular shape by the cutter unit 30, the excavated soil including the rocks and the like generated by the excavation is accommodated in the rotating unit shell 20 and is not closed by the closing plate of the gap 20D. It falls from the part and is discharged into the inner space of the excavator 10. The excavated soil discharged from the rotating part shell 20 is deposited on the excavated soil receiving plate 100.

  In addition, the cylindrical ground 72 left after the ground is excavated in an annular shape by the cutter unit 30 is crushed by the breaker 62. The excavated soil generated by crushing the ground with the breaker 62 is sent to the crusher 106 together with the excavated soil excavated by the cutter unit 30 and finely crushed. The excavated soil crushed by the crusher 106 falls onto the conveyor 81, is carried to the slipping area 9 by the conveyor 81, and is discharged out of the tunnel by a dump truck or the like.

  In parallel with the excavation process by the excavator 10, the construction work of the liner support is performed behind the excavator 10. The construction work of the liner support work includes an assembly work for assembling the liner in an annular shape and a backfilling operation for filling the outer periphery of the liner assembled in an annular shape with mortar.

First, assembly work for assembling the liner in an annular shape will be described.
As described with reference to FIGS. 8A to 8C, the liner assembly operation is performed in the cylindrical member 110 in parallel with the operation of moving the excavator 10 forward. First, as described with reference to FIG. 8C, the rear axial jack 50 is contracted in a state where the front radial jack 54 is extended outward in the radial direction and the surrounding ground is pressed. . In this state where the rear axial jack 50 is contracted, the rear end of the tubular member 110 is positioned on the outer periphery of the liner support 120 that has already been constructed.

  Next, as shown in FIG. 8C, the propulsion jack 57 is contracted. As a result, a gap is generated between the rear end of the propulsion jack 57 and the liner support 120 already constructed. Next, as shown in FIG. 8D, the liner 120 </ b> A is connected in the circumferential direction so as to form an annular shape along the inner surface of the cylindrical member 110 inside the cylindrical member 110. The liner 120A is made of, for example, an RC liner made of reinforced concrete formed in an arc shape. The RC liner may be manufactured at a factory or the like, but is preferably manufactured on site. The liner 120A also has an injection hole 120B (FIG. 9) for filling mortar in the backfill injection operation between the front and back surfaces. In addition, the liner 120A is connected in an annular shape, and is connected to the tip of the liner support 120 that has already been constructed. As a method for connecting the liner 120A, a conventionally known method can be used. For example, a metal fitting for connection may be used.

  Next, the backfilling operation for filling the outer periphery of the liner support 120 thus constructed with mortar will be described. The backfilling operation is performed in a region where the excavator 10 advances and the cylindrical member 110 is not interposed between the liner support 120 and the wall surface of the ground 122 excavated by the excavator 10.

  FIG. 9 is a diagram for explaining a method of performing the backfill injection operation. As shown in FIG. 9A, first, in a predetermined section behind the excavator 10 (section A in FIG. 9A), an annular cross section between the liner support 120 and the surrounding ground 122 is obtained. A first injection process is performed in which mortar is filled in a region below a predetermined height in the space. For example, the region filled with mortar in the first injection step may have a lower 120 ° range (a 60 ° range from the lower side to the left) in the vertical cross section of the tunnel as shown in FIG. 9B. . As shown in FIG. 9 (B), when the mortar is filled in advance, the injection hole 120B of the highest liner 120A among the liners 120A located in the lower 120 ° range (FIG. 9 (A), The mortar 130 may be injected from the injection hole 120B indicated by the arrow a in (B). At this time, as shown in FIG. 9C, excavated soil 132 generated by excavating the ground by the excavator 10 is formed in the lower part of the space of the annular cross section between the liner support 120 and the surrounding ground 122. Has entered. Further, the excavated soil 132 is compacted because the excavator 10 passes above. In this way, since the excavated soil 132 enters the lower part of the space of the annular cross section between the liner support 120 and the surrounding ground 122, the lower part of the liner support 120 is surrounded by the surrounding ground 122 with a small amount of mortar. Can be integrated.

  Next, in a predetermined section behind the section in which the mortar is filled in advance (section B in FIG. 9B), the predetermined space in the annular cross section between the liner support 120 and the surrounding ground 122 is predetermined. A second injection step of filling the region above the height with mortar is performed. In filling the mortar in the second injection step, the injection hole 120B of the uppermost liner 120A among the annularly connected liners 120A (injection indicated by an arrow b in FIGS. 9A and 9B) The mortar 130 may be injected from the holes 120B). As described above, by performing the first injection step and the second injection step, the outer periphery of the liner support 120 is filled with the backfill mortar, and the ground can be firmly supported.

According to this embodiment, the following effects are exhibited.
In this embodiment, since the liner 120A is annularly assembled in the cylindrical member 110 that surrounds the rear end portion of the excavating apparatus 10 and extends rearward of the apparatus main body, the liner supporting work is such that the outer diameter is equal to the outer diameter of the apparatus main body. 120 can be assembled. Thereby, the space | interval of the clearance gap between the liner 120A assembled in cyclic | annular form and the wall surface of the ground excavated by the cutter part 30 can be made small, and the quantity of the filler with which this clearance gap is filled can be reduced. And since the quantity of a filler can be reduced without throwing a cobblestone etc. between liner 120A and a tunnel inner wall in this way, it can reduce cost, without reducing a construction speed.

  In addition, according to the present embodiment, the ground is excavated in an annular shape in advance by the annular cutter portion 30, and the inner portion excavated in an annular shape in parallel with this is excavated in the apparatus main body. The excavation speed can be improved.

  Further, according to the present embodiment, in the backfill injection step of injecting mortar into the annular cross-sectional space between the wall surface of the ground excavated by the cutter unit 30 and the liner 120A assembled in an annular shape, the annular cross-sectional space The first injection step of injecting the filler into the portion below the predetermined height of the first and the second injection step of injecting the filler into the portion above the predetermined height of the annular cross-sectional space are performed. . Excavated soil 132 generated by excavating the ground enters the lower part between the annularly assembled liner 120A and the wall surface of the ground excavated by the cutter unit 30, and this excavated soil 132 tunnels upward. Since the excavator 10 is passing, it is compacted. For this reason, the lower part of the liner support 120 can be integrated with the ground only by injecting a small amount of filler in the first injection step.

  Moreover, according to this embodiment, the tunnel excavation apparatus 10 has the propulsion jack 57 which can be extended toward the back in the lower part of the apparatus back. As described above, the lower portion of the liner 120A is integrated with the ground prior to the first injection step. For this reason, according to this embodiment, since the reaction force can be taken by the propulsion jack 57 at the lower portion of the liner 120A, the ground can be excavated with the cutter unit 30 pressed against the ground with a stronger force.

  In this embodiment, the case where the ground is excavated in an annular shape by the annular cutter unit 30 has been described. However, the present invention is not limited to this, and the cutter unit 30 may be circular and the ground may be excavated in a circular shape.

DESCRIPTION OF SYMBOLS 10 Excavator 12 Shell 14 Excavation mechanism 16 Excavation soil carry-out mechanism 18 Propulsion mechanism 20 Rotating part shell 20A End surface part 20B Outer cylinder 20C Inner cylinder 20D Gap 20E Space 20F Chamber 22 First fixed part shell 22B Outer cylinder Body 22C Inner cylinder 24 Second fixed part shell 24B Outer cylinder 24C Inner cylinder 26 Third fixed part shell 26B Outer cylinder 26C Inner cylinder 30 Cutter part 32 Reducer 33 Ring 34 Motor 35 Pin rack 36 Opening 37 Pinion 38 Roller bit 40 Drilling bit 42 Plate material 44 Closing plate 50 Rear axial jack 52 Front axial jack 54 Front radial jack 56 Rear radial jack 57 Propulsion jack 62 Breaker 70 Base 72 Ground 81 Conveyor 100 excavated earth receiving plate 106 rock crusher 110 cylindrical member 120 liner support 120A liner -120B Injection hole 122 Ground 130 Excavated soil

Claims (2)

An apparatus main body, a cutter head that is provided at a front end of the apparatus main body and is rotatable with respect to the apparatus main body, and a cylindrical member that surrounds a rear end portion of the apparatus main body and extends rearward of the apparatus main body. A tunnel excavation method using a tunnel excavator,
A first excavation step of excavating the ground by rotating the cutter head relative to the apparatus main body;
An apparatus advance step for advancing the tunnel excavator;
A liner assembling step for annularly assembling a liner in the tubular member so as to be continuous with the front end of the liner support already constructed;
A backfill injection step of injecting a filler into an annular cross-sectional space between the wall surface of the ground excavated by the cutter head and the liner assembled in an annular shape ,
The backfill injection step includes a first injection step of injecting the filler into a portion having a predetermined height or less in the annular cross section space, and a portion above the predetermined height of the annular cross section space. A second injection step of injecting a filler,
The tunnel excavator has a propulsion jack that is arranged to extend in the front-rear direction below the rear end portion and can extend and contract toward the rear,
In the device advancing step, the tunnel excavating device is advanced by taking a reaction force on the lower part of the liner integrated with the ground by the first injection step . The cutter head is annular;
In the first excavation step, excavating the ground in an annular shape,
And a second excavation step of excavating the annularly excavated inner portion of the ground within the apparatus main body.
The tunnel excavation method according to claim 1.

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