JP2008002070A - Tunnel excavator, reaming tunnel excavator and excavating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the term of works by accelerating the progress of a tunnel excavation for the conventional primary timbering and secondary lining work. <P>SOLUTION: This reaming excavator, which enlarged-diameter excavates an advanced pilot tunnel 11 to an enlarged-width pit 12 includes: a cutter rotated in the tunnel peripheral direction in the enlarged-width pit 12; a first protector 14 moving interlocking with the cutter 5 in excavation and shaped cylindrical; a second protector 16 moving a range of overlapping the first protector 14 and a segment 3 between the first protector 14 and the segment 3; and an elector device 20 for assembling a new segment 3b to the existing segment 3a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tunnel excavator, a reaming tunnel excavator, and an excavation method.

Conventionally, when excavating a large-diameter tunnel, for example, after excavating the advanced guide shaft with a tunnel excavator for advanced guide shafts in advance, it is advanced with a tunnel excavator for widening shafts (hereinafter referred to as a reaming excavator). The diameter of the shaft was expanded.
As a configuration of this reaming excavator, for example, as described in Patent Document 1, a cutter for expanding the diameter, a propulsion jack for propelling the cutter, and a gripper that takes the reaction force of the propulsion jack on the tunnel well wall And. The support structure by the reaming excavator uses the primary support by the NATM method such as steel support, shotcrete, rock bolt, etc., and the support provided by combining the above primary support in combination with the deterioration of the ground condition. It is common to strengthen the structure.
The excavation method using such a reaming excavator usually applies a reaction force by pressing a gripper against the tunnel wall surface and applies a thrust to the rotating cutter by the propulsion jack, for example, excavating the stroke of the propulsion jack. To do. Then, if necessary, the primary excavation work is performed before the next excavation. Normally, the traveling speed of a tunnel in a reaming excavator is, for example, 300 m or more per month under normal ground conditions where the support structure is simple.
In addition, in soft ground, secondary lining is applied as needed in addition to primary support. In this construction, a concrete structure with a certain thickness is constructed on the inner side of the tunnel excavation surface by placing concrete using a tunnel form behind the place where the primary support was carried out (starting side of the reaming excavator). . Normally, the looseness of the natural ground becomes larger at the place where the secondary lining is to be constructed, so it is necessary to perform the secondary lining within the earliest possible time after the construction of the primary support. Therefore, the construction position of the secondary lining has been set so as not to leave the distance from the construction position of the primary support.
Japanese Patent No. 3530618

However, in the above-described reaming excavator, if the cutter is rotated during excavation during the primary support operation, the natural ground in the middle of the support is loosened and further collapse of the natural ground occurs. there were. For this reason, during the work of primary support, the excavation is stopped, and there is a problem that the traveling speed of the tunnel decreases. In particular, when encountering soft ground, the support structure will be strengthened, and the time required for support work will increase accordingly.
Also, usually, secondary lining uses tunnel formwork, for example, with a placement length of about 10.5m per time. For each placement, tunnel formwork set and concrete placement The process is repeated while repeating the work of concrete curing. For this reason, in the construction of secondary lining, it is difficult to obtain a progress of about 300 m per month as in tunnel excavation, and it is usually about 100 m per month (per tunnel formwork). Even if two tunnel molds are used, there is a disadvantage that the traveling speed by the reaming excavator cannot be followed and the distance between the primary support and the secondary lining is increased. Therefore, the tunnel excavation speed largely depends on the work time of the primary support and the secondary lining, and it becomes a low speed according to the progress of the secondary lining, so there is a problem that the construction period becomes long. .

  The present invention has been made in view of the above-described problems. A tunnel excavator and a reaming machine that shorten the construction period by speeding up the progress of tunnel excavation with respect to the conventional primary support and secondary lining work. A tunnel excavator and an excavation method are provided.

To achieve the above object, in the tunnel excavator according to the present invention, a main beam, a cutter provided on the main beam, a first protector fixed to the main beam behind the cutter, and a rear of the first protector. A second protector that is slidably attached to the main beam and overlaps the first protector; segment assembly means that is slidably attached to the main beam and assembles a new segment in the second protector; and slides on the main beam. It is characterized by comprising a gripper that is movably attached and abuts against a tunnel wall surface.
In the reaming tunnel excavator according to the present invention, in the tunnel excavator described above, the main beam extends forward from the cutter, and the front end of the main beam is slidably attached to the main beam. It has a structure having a gripper, and is characterized in that the front gripper can be positioned in an advanced tunnel of a tunnel.
In this invention, a 2nd protector can move within the range which overlaps with a 1st protector and an existing segment. For this reason, since the tunnel wall surface is not exposed, and the fall of the natural ground and the skin fall can be protected to ensure the safety, the conventional primary support and secondary lining work can be omitted. When the overlapping length with the existing segment becomes small, the segment assembling work can be performed by the segment assembling means. Moreover, even during the assembly of the segment, it is possible to dig while advancing the cutter within the range of overlap between the first protector and the second protector. Thus, simultaneous excavation and segment assembly are possible, and tunnel tunneling can be speeded up.

In the reaming tunnel excavator according to the present invention, the first jack for moving the second protector in the longitudinal direction of the tunnel and the second jack for pressing the new segment against the existing segment may be connected to the second protector. preferable.
In the present invention, the first protector can move the second protector regardless of the movement due to the excavation. For this reason, during excavation, a new segment can be pressed against an existing segment while taking a reaction force with the second jack.

In the reaming tunnel excavator according to the present invention, an auxiliary gripper is provided on a support member that supports the second protector from the inner side of the tunnel, and the auxiliary gripper is stretched toward the tunnel wall surface when the segment is pressed by the second jack. It is preferable that it is comprised so that it may take out.
In the present invention, the support member can be fixed at a predetermined position by pressing the auxiliary gripper against the tunnel wall surface and taking the reaction force when tunneling and extending the first jack and the second jack. . Thereby, the support member can prevent the vibration of the cutter and can press the segment with the second jack.

In the reaming tunnel excavator according to the present invention, it is preferable that the segment assembling means includes an erector device that is interlocked with the movement of the support member.
In the present invention, the segment assembly work position is the inner space side of the second protector, and the segment can be safely assembled by positioning the segment with the erector device.

Further, the excavation method according to the present invention is an excavation method for excavating using the tunnel excavator described above, wherein the first protector is advanced in a range overlapping with the second protector in conjunction with the cutter for excavating the tunnel. The first step of moving in the forward direction and the second step of moving the second protector within a range overlapping the first protector and the existing segment, the overlap length of the second protector and the existing segment is reduced In some cases, a new segment is assembled to the existing segment by the segment assembling means.
In the present invention, for example, when the overlap length between the first protector and the second protector is small and the overlap length between the second protector and the existing segment is large, the first protector is interlocked with the cutter in the first step. When moving forward, the overlap length of the first protector and the second protector is reduced. Then, in the second step, when the second protector is moved forward and the overlap length between the second protector and the existing segment becomes small, a new segment assembly operation can be performed on the existing segment. Thus, since excavation with a cutter can be performed at the time of segment assembly, the progress of the tunnel can be increased.

According to the tunnel excavator, the reaming tunnel excavator and the excavation method of the present invention, the second protector can move within a range overlapping with the first protector and the existing segment. For this reason, since the tunnel wall surface is not exposed, and the fall of the natural ground and the skin fall can be protected to ensure the safety, the conventional primary support and secondary lining work can be omitted. When the overlapping length with the existing segment becomes small, the segment assembling work can be performed by the segment assembling means. Moreover, even during the assembly of the segment, it is possible to dig while advancing the cutter within the range of overlap between the first protector and the second protector.
In this way, by enabling simultaneous construction of excavation and segment assembly, it becomes possible to perform segment assembly work substantially continuously, and to make the assembly construction speed faster than the speed of conventional secondary lining. Can do. Therefore, the tunnel advancing speed can be increased in accordance with the increased construction speed of the segment assembly, and the high-speed excavation performance of the tunnel excavator can be sufficiently exhibited, so that the construction period can be shortened.

Hereinafter, embodiments of a tunnel excavator, a reaming tunnel excavator, and a excavation method according to the present invention will be described with reference to FIGS.
1 is a side view showing the whole reaming excavator according to the embodiment, FIG. 2 is a cross-sectional view of the reaming excavator shown in FIG. 1, taken along line AA, and FIGS. 3 (a) and 3 (b) show the operating state of the protector. FIGS. 4A to 4D are diagrams illustrating a drilling method by the reaming excavator according to the embodiment.

First, in the following description, the forward direction in the tunnel traveling direction is “front” or “face side”, and the opposite direction is “rear”.
As shown in FIG. 1, the tunnel 1 in the embodiment is based on a TBM (tunnel boring machine) method, in which a circular advanced tunnel 11 is previously excavated by an advanced tunnel excavator (not shown). Thus, the widening pit 12 is formed by expanding the diameter of the advanced guiding pit 11 coaxially using the reaming excavator 2 (tunnel excavator) of the present embodiment. Further, behind the reaming excavator 2, the segment 3 is constructed simultaneously with the progress of excavation.
In addition, the widening face 12a is formed in the boundary of the advanced guiding pit 11 and the widening pit 12 during diameter expansion excavation.

As shown in FIG. 1, the reaming excavator 2 is provided with a main beam 4 that is formed as a long beam and that extends over the advanced guide shaft 11 and the widening shaft 12 with the longitudinal direction directed to the tunnel traveling direction. Yes. This main beam 4 is the main axis of the reaming excavator 2, and a reaction force is applied to the bottom of the tunnel 1 by the front support 6 provided in the advanced guide shaft 11 and the rear support 7 provided in the widening shaft 12. Supported from below.
As shown in FIG. 1, the reaming excavator 2 has a circular widening outer diameter at the position of the widening face 12 a and having a rotation surface in a direction orthogonal to the traveling direction of the reaming excavator 2, A cutter 5 provided to be rotatable is provided. The cutter 5 includes a large number of circular roller cutters 13 having, for example, a abacus ball shape on the surface on the widening face 12a side, and is rotated and excavated around the tunnel axis by a cutter driving motor (not shown).

  Further, as shown in FIG. 1, the reaming excavator 2 includes a propulsion mechanism S that is provided at the front end side of the main beam 4 and is pulled in the tunnel traveling direction in front of the cutter 5, and between the cutter 5 and the segment 3. A protective mechanism U that protects against the collapse of a natural ground by covering the exposure of the tunnel wall surface that has been excavated in diameter, and a segment assembly means V for assembling the segment 3 on the inner side of the protective mechanism U; Is provided.

As shown in FIG. 1, the propulsion mechanism S is provided so as to be slidable in the axial direction of the main beam 4 along the peripheral portion of the main beam 4. A rear gripper 10 located in the pit 12 is provided. The front gripper 8 and the rear gripper 10 include a plurality of jacks 8a and 10a that expand and contract in the tunnel radial direction, and face plates 8b and 10b that are fixed to the ends of the jacks 8a and 10a and have an arc shape. By overhanging, a reaction force is taken by the face plates 8b and 10b contacting the respective tunnel wall surfaces. The front gripper 8 and the rear gripper 10 correspond to the “gripper” of the present invention.
Further, the propulsion mechanism S is provided with a plurality of propulsion jacks 9 that have one end 9a fixed to the front gripper 8 and the other end 9b fixed to the main beam 4 to expand and contract in the longitudinal direction of the tunnel.

As shown in FIGS. 1 to 3, the protective mechanism U includes a first protector 14 having a cylindrical shape slightly smaller than the inner diameter of the widening pit 12 and a first outer periphery 15 a on the rear side from the rear end 5 a of the cutter 5. And a first ring beam 15 which is fixed to the inner peripheral surface 14a of the protector 14 and formed in an annular shape. The first ring beam 15 is fixed to the main beam 4 via a connecting member (not shown) at the inner periphery 15b.
As shown in FIG. 1, the front end 14b of the first protector 14 and the rear end 5a of the cutter 5 have a slight gap. Note that the cutter 5 is rotatably provided with respect to the first protector 14.

Further, as shown in FIGS. 1 to 3, the protection mechanism U is fixed to a second protector 16 having a slightly smaller diameter than the first protector 14 and an inner peripheral surface 16 a of the second protector 16 and is tunneled. A second ring beam 17 (supporting member) formed annularly in the circumferential direction is provided. The second ring beam 17 is slidably attached to the main beam 4 along with the second protector 16 in the tunnel traveling direction. As shown in FIG. 3, the second protector 16 is connected to the first protector 14. The first protector 14 is within a range in which the outer peripheral surface 16b overlaps the segment 3 with the rear inner peripheral surface 14c of the first protector 14 and the inner peripheral surface 16a overlaps with the outer periphery of the existing segment 3a in the tunnel front-rear direction. Move along. In this way, the second protector closes the tunnel wall surface without exposing it. Then, the segments 3 are sequentially assembled on the inner peripheral surface 16 a side of the second protector 16.

As shown in FIGS. 3A and 3B, a predetermined distance is provided between the first ring beam 15 and the second ring beam 17 in the circumferential direction of a slide jack 18 (first jack) that expands and contracts in the tunnel longitudinal direction. A plurality are connected at intervals (see FIG. 2). The length of the slide jack 18 is set to such a length that the first protector 14 and the second protector 16 are not overlapped when extended.
These slide jacks 18 can be expanded and contracted independently without being interlocked with the excavation by the cutter 5, and the positional relationship between the first ring beam 15 and the second ring beam 17 according to the working state such as excavation and segment assembly. Can be controlled. For example, when excavating during segment assembly, the first ring beam 15 advances in conjunction with the excavation by the cutter 5, so that the distance between the first ring beam 15 and the second ring beam 17 at the fixed position is increased. . For this reason, the slide jack 18 is set in a free state so that it can be extended in conjunction with the excavation (see FIG. 4B).
Further, as shown in FIGS. 1 and 2, a shield jack 19 (second jack) that extends and contracts in the longitudinal direction of the tunnel at a predetermined interval in the circumferential direction between the rear end surface 17c of the second ring beam 17 and the segment 3 is provided. A plurality are provided. When the shield jack 19 is extended, the tip 19a abuts against the segment 3 and is pressed. At the time of assembling the segment in a state where the second protector 16 and the second ring beam 17 are advanced, the shield jack 19 at the position where the segment 3 is assembled is contracted to form the assembly region R.

As shown in FIG. 1, the segment assembling means V has a gripping and positioning function during segment assembling, and is equipped with an erector device 20 that rotates while being guided by the inner peripheral surface 17 a of the second ring beam 17. . In addition to turning, the erector device 20 can be operated to finely adjust, for example, up, down, left, and right, thereby performing segment positioning operation.
And as shown in FIG. 3, the shield jack 19 can press the new segment 3b arrange | positioned in the predetermined position by the erector apparatus 20 sequentially to the existing segment 3a.
As shown in FIG. 3, auxiliary grippers 21 projecting outward in the radial direction are provided at a plurality of locations (for example, 6 to 8 locations) on the outer peripheral surface 17 b of the second ring beam 17.

As shown in FIG. 1, as an incidental facility for the reaming excavator 2, a work platform 22 that is connected to the rear of the main beam 4 and moves forward simultaneously with excavation is provided. The work platform 22 serves as a work scaffold for assembling the segment 3 and is also used as a place for materials and equipment. The work platform 22 is provided with a shape holding device 23 that supports the segment 3 from the inner space side and prevents the ring-shaped segment 3 from collapsing. The shape holding device 23 has an arc shape whose outer circumference is the same as the inner diameter of the segment. For example, an internal jack (not shown) is pressed against the inside of the segment 3 assembled in a ring shape.
Further, the excavated earth and sand are scraped upward by a scraping plate (not shown) provided in the cutter 5 and taken into a bucket (not shown), for example, a continuous belt on the rear side via a belt conveyor or the like. It is sent to sediment transport equipment such as conveyors and steel cars.

Next, the operation of the reaming excavator 2 having such a configuration and the excavation method will be described.
First, as shown in FIG. 4 (a), the tunnel excavation rotates the cutter 5 after extending the front gripper 8 in the advanced guiding pit 11 and the rear gripper 10 in the widening pit 12 to the respective wall surfaces and taking a reaction force. The propulsion jack 9 is extended while letting it go. Then, the cutter 5 obtains a propulsive force toward the face via the main beam 4, and excavation of the widened face 12a is started.

  Subsequently, as shown in FIG. 4B, the first protector 14 is fixed to the main beam 4 via the first ring beam 15, and therefore always moves forward in conjunction with the excavation by the cutter 5. . At this time, the first protector 14 moves within a range overlapping the second protector 16. That is, the overlap length between the first protector 14 and the second protector 16 is reduced.

As shown in FIG. 4 (c), when the excavation for one digging length is completed, the front support 6 and the rear support 7 are extended until they abut against the tunnel wall surface of the tunnel 1 to support the main beam 4, and then the tunnel wall surface is counteracted. The front gripper 8 and the rear gripper 10 that have taken the force are shrunk.
As shown in FIG. 4C, the second protector 16 is slidably provided on the main beam 4, and therefore does not interlock with the excavation by the cutter 5.
When the excavation for one digging length is completed, when the slide jack 18 is contracted after the auxiliary gripper 21 is contracted, the first ring beam 15 is fixed, so the second ring beam 17 and the second protector 16 move forward. To do. That is, the overlap length between the first protector 14 and the second protector 16 is increased, and the overlap length between the second protector 16 and the existing segment 3a is decreased. When the shield jack 19 at the assembly position of the segment 3 is contracted, an assembly region R is formed between the second ring beam 17 and the existing segment 3a, and a new segment 3b can be assembled in this assembly region R. .
The first protector 14 and the second protector 16, and the second protector 16 and the segment 3 are always overlapped because the extension distance of the slide jack 18 is limited. There is no danger of collapse or skin fall, and safe work can be performed.
Then, the propulsion jack 9 extending for one digging length is shrunk and the front gripper 8 is changed to the front to complete preparation for the next digging.

Next, the procedure for assembling the segments will be described. As shown in FIG. 4D, the auxiliary gripper 21 is pressed against the wall surface 12b of the widening pit 12 to take a reaction force and fix the second ring beam 17 at a predetermined position. Thereby, the reaction force when pressing the shield jack 19 against the segment 3 can be applied to the second ring beam 17. In addition, the erector device 20 is not subjected to vibration of the cutter 5.
The segment 3b to be newly assembled is positioned at the assembly position adjacent to the existing segment 3a using the erector device 20 on the inner space side of the second protector 16, and is pressed against the existing segment 3a by the shield jack 19. Then, the adjacent segments 3 are fixed using, for example, bolts, and the segments 3 for one ring are assembled.
The subsequent steps are a repetition of the above-described work procedure, but the next excavation can be performed simultaneously with the assembly work of the segment 3.

In the tunnel excavator, the reaming tunnel excavator, and the excavation method according to the present embodiment, the first protector 14 and the second protector 16 are provided so as to close the tunnel wall that has conventionally required primary support. Since there is no exposure and it is possible to secure the safety by protecting the fall of the tunnel wall surface and skin, the conventional primary support and secondary lining work can be omitted.
And the assembly work of the segment 3 can be performed on the inner space side of the second protector 16. In addition, for example, when the second protector 16 is in a fixed position at the time of assembling the segment, the cutter 5 can be advanced and dug within a range where the first protector 14 overlaps the second protector 16.
As described above, since the excavation and the segment assembly can be performed simultaneously, the segment assembly operation can be performed substantially continuously. In the present embodiment, the assembly time of the segment 3 can be, for example, about 40 to 100 minutes per ring, and can be expected to be 500 m or more in progress per month. This is about five times as much as the progress of about 100 m in the conventional secondary lining. Thus, the construction speed of the segment assembly becomes faster than the construction speed of the conventional secondary lining. Therefore, the tunnel advancing speed can be increased in accordance with the increased construction speed of the segment assembly, and the high-speed excavation performance of the tunnel excavator can be sufficiently exhibited, so that the construction period can be shortened.

The tunnel excavator, the reaming tunnel excavator, and the excavation method according to the embodiment of the present invention have been described above. However, the present invention is not limited to the above-described embodiment, and may be appropriately changed without departing from the spirit of the present invention. Is possible.
For example, in the present embodiment, the first and second protectors 14 and 16 have a substantially cylindrical shape. However, the first and second protectors 14 and 16 are not necessarily limited to being provided on the entire circumference like a cylindrical shape, and at least the tunnel top end. The protector may be a substantially arc-shaped protector that can protect the natural ground. For example, instead of the second protector 16 in the embodiment, a semi-cylindrical protector may be provided so as to cover the tunnel top end portion and disposed only above the cross section of the widening pit 12. In this case, since the tunnel wall surface is exposed in the lower part, it is preferable to apply to the tunnel 1 with less soft ground where the tunnel wall surface collapses over the entire circumference of the tunnel, as in the second protector 16 of the embodiment. The segment 3 can be assembled on the inner side.
Moreover, in this Embodiment, although it was set as the reaming excavator 2 which excavates a widening pit using an advanced guiding mine, it is not limited to the structure where the main beam was extended ahead of the cutter. In that case, it becomes a tunnel excavator for excavating a tunnel without an advanced tunnel.

1 is a side view showing an entire reaming excavator according to an embodiment of the present invention. It is an AA line sectional view of the reaming excavator shown in FIG. (A), (b) is an enlarged view which shows the operating state of a protector. (A)-(d) is a figure which shows the excavation method by the reaming excavator of embodiment.

Explanation of symbols

1 Tunnel 2 Reaming Excavator (Tunnel Excavator)
3 Segment 3a Existing segment 4 Main beam 5 Cutter 8 Front gripper (gripper)
10 Rear gripper (gripper)
DESCRIPTION OF SYMBOLS 11 Advanced guide shaft 12 Widening shaft 12a Widening face 14 First protector 15 First ring beam 16 Second protector 17 Second ring beam (supporting member)
18 Slide jack (first jack)
19 Shield jack (second jack)
20 Elector Device 21 Auxiliary Gripper R Assembly Area S Propulsion Mechanism U Protection Mechanism V Segment Assembly Means

Claims (6)

The main beam,
A cutter provided on the main beam;
A first protector fixed to the main beam behind the cutter;
A second protector slidably attached to the main beam behind the first protector and overlapping the first protector;
Segment assembling means that is slidably attached to the main beam and assembles a new segment in the second protector;
A gripper that is slidably attached to the main beam and abuts against a tunnel wall;
A tunnel excavator characterized by comprising: The tunnel excavator of claim 1,
The main beam extends forward from the cutter, and has a front gripper slidably attached to the main beam at a front end side of the main beam. Reaming tunnel excavator characterized in that it can be located in   The first jack that moves the second protector in the longitudinal direction of the tunnel and the second jack that presses the new segment against the existing segment are connected to the second protector. Reaming tunnel excavator.   An auxiliary gripper is provided on a support member that supports the second protector from the inside of the tunnel, and when the segment is pressed by the second jack, the auxiliary gripper is configured to project toward the tunnel wall surface. The reaming tunnel excavator according to claim 2 or 3. The reaming tunnel excavator according to any one of claims 2 to 4, wherein the segment assembling means includes an erector device that interlocks with the movement of the support member.
A drilling method for excavating using the tunnel excavator according to any one of claims 1 to 5,
A first step of moving the first protector in front of the traveling direction within a range overlapping the second protector in conjunction with the cutter excavating a tunnel;
A second step of moving the second protector within a range overlapping the first protector and the existing segment;
With
The excavation method characterized in that when the overlap length between the second protector and the existing segment becomes small, the new segment is assembled to the existing segment by segment assembling means.

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