JP3386197B2 - Arch tunnel excavator for hard rock - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly required for excavating a wide tunnel (hereinafter also referred to as a wide main tunnel) having an arcuate upper surface, for example, as a multi-lane facing road tunnel in a bedrock section. The present invention relates to an arcuate tunnel excavator for hard rock, which is effective for excavating a tunnel (hereinafter also referred to as an arcuate tunnel) in which a tunnel having a circular cross section partially overlaps and continues in an arcuate shape.

[0002]

2. Description of the Related Art When excavating a wide tunnel, the NATM (New Austrian tunneling Method) method has been generally adopted. This method involves spraying concrete onto the excavated surface while holding the excavated surface after the support structure is assembled to prevent ground collapse, especially in the upper and lateral sides after excavating the arched tunnel using a small excavator. , Embed the lock bolt from the concrete spray surface and tighten. Then, the lower part of the tunnel will be excavated to form a wide tunnel. Further, a bench cut method is one of the NATM methods. In the case of this method, the excavated cross section is divided into several sections and excavated in order, but at each excavation site, support work is set up to hold the excavated surface, and concrete is sprayed onto the excavated surface to collapse the ground. It is basically the same as the former in that it prevents For excavating a tunnel with a circular cross section in the bedrock part, a hard rock tunnel excavator called a TBM in which a roller disc is arranged on a cutter disk can be used, but in general, blasting (blasting with dynamite) is used. ing.

Prior art publications relating to the above-mentioned NATM method include JP-A-1-295992 and JP-A-3
There is another construction method described in No. 257292. This construction method (P
The ATM method) first drills a circular hole with an earth auger, and then reciprocally rocks a triangular bucket (cutter) on both sides of the circular hole to drill a slot having a rectangular cross section. In parallel, concrete is filled in the slots to form a series of continuous arched prelinings. Then, by excavating the ground surrounded by the lining, a wide tunnel will be completed.

[0004]

The above-mentioned NATM method or the latter PATM method has the following disadvantages.

In the case of the NATM method, the work for preventing the collapse of the ground by spraying concrete takes several times as long as the excavation work, and the work for preventing the collapse cannot be performed in parallel with the excavation work. For this reason, the work as a whole requires a long time, the work efficiency is very poor, and when the tunnel cross-sectional area is about 150 to 200 m ² , the tunnel excavation distance is very short at 30 to 40 m / month.

In the case of the PATM method, the excavation target is soft ground such as silt, clay, sand, etc., and since a slot is formed by cutting with a bite cutter, it cannot be applied to excavation in the bedrock portion.

An object of the present invention is to solve the above-mentioned problems of the prior art, and is used for excavating a bow-shaped tunnel when efficiently excavating a wide tunnel having an arch-shaped upper surface in a bedrock part. It is to provide a bow-shaped tunnel excavator for hard rock.

[0008]

According to the bow tunnel excavator for hard rock of the present invention, A) a plurality of circular cross-section openings are partially overlapped and continuously arranged in an arc shape, and the inside is communicated. An excavator main body provided with a shield, and an arc-shaped thrust support frame and a plurality of shield jacks, one end of which is attached to the thrust support frame and is telescopically driven rearward, and B) of this excavator main body. At the front end, they are alternately arranged in the front-rear direction in a series of arcuate shapes, and are arranged so as to be movable back and forth with respect to the excavator body through thrust jacks, respectively, and a hard rock cutter disk and a cylindrical shape following it. Alternatively, a plurality of hard rock tunnel excavating means having a substantially cylindrical shield are provided.

[0009]

According to claim 2 , A) a circular cross section
Inside an arcuate opening formed by continuously moving in an arc shape
A shield that communicates with the
It is equipped with a shield that is continuously arranged in the shape of a bow and has a shield that communicates with the inside as a unit. Inside this shield, a bow-shaped thrust support frame and a plurality of shields that have one end attached to this thrust support frame and are driven to extend and retract rearward. B ") Excavator body with jack and B") At the front end of this excavator body, a hard disk cutter disk and a cylinder following it are arranged so that they can reciprocate in an arch shape when viewed from the front of the tunnel. A hard rock tunnel excavating means having a shape or a substantially cylindrical shield, and C ″) a front end in the excavator body
Arranged an arch-shaped stair rack (63) in the
One end of the telescopic jacks (64) and (65) of the above
Pivotally attached to the tunnel excavation means for one of the jacks (6)
4) The step where the jack (65) is engaged by contracting
Engage the other end of the jack (64) with the difference part (63a),
In this state, the two jacks (64) and (65) are simultaneously
By extending to the hard rock tunnel excavation means
Move in an arch along the rack (63),
Then, by contracting one of the jacks (65)
The other end to the upper step (63b).
By repeating the above-mentioned operation of
Even if you move the tunnel excavation means in an arch
Good.

[0011]

According to the bow tunnel excavator for hard rock according to the present invention, the arch tunnel is excavated in the bedrock portion by the plurality of tunnel excavating means at the tip due to the configuration of B). Since each of the tunnel excavating means can move back and forth, the excavation speed is adjusted to match the tunnel excavating means with the slowest excavation time even if the rock excavation means excavates the rocks at different degrees of hardness. With the configuration of A), the excavated surface of the ground excavated by the tunnel excavation means can be held by the shield of the excavator body until the arch-shaped ceiling wall is assembled, and excavation work can be performed during that time. You can continue. Further, since the arch-shaped ceiling wall is assembled within the shield, the assembly work is performed safely, and the lock bolts and the like used in the NATM method are completely unnecessary. In this way, when the bow-shaped tunnel to be excavated by the tunnel excavating means at the tip reaches a predetermined distance, in other words, each tunnel excavating means is moved to the excavator body (of the thrust jack).
When advanced to the stroke end, the excavator main body can be advanced to the tunnel excavation means side and returned to the original state by extending the shield jack by using the arch-shaped ceiling wall constructed in the rear as a reaction force receiver. After that, by excavating the above-described excavation work, the excavation work of the arcuate tunnel can be performed.

[0012]

In the tunnel excavating machine according to the second aspect, the independent hard rock tunnel excavating means reciprocates in an arch shape at the front end thereof to excavate the arcuate tunnel. Direction of the cutter disk of the tunnel excavation means (angle to the ground)
The angle can be changed to vertical, 45 °, 90 ° depending on the rock quality of the natural ground and the situation. The tunnel excavation means is 1
In the case of a platform, the arcuate tunnel is reciprocally moved over the entire width, but normally, two tunnel excavating means are moved in opposition to each other, and half of the tunnel width is shared by each tunnel excavating means. The excavated surface of the natural ground excavated by the tunnel excavation means can be held by the shield of the excavator main body until the arch-shaped ceiling wall is assembled, and the excavation work can be continued during that time. The point that the arch-shaped ceiling wall is assembled in the shield is the above-mentioned item 1.
It is the same as the tunnel excavator. When the arch-shaped tunnel of a predetermined length is further excavated by the tunnel excavating means, the shield jack is extended by using the arch-shaped ceiling wall formed behind it as a reaction force receiver to advance the excavator body to the tunnel excavating means side. It is the same in that it can be restored to the original state.

[0014]

1 to 4 show a hard rock bow-shaped tunnel excavator 1 according to a first embodiment of the present invention. This tunnel excavator 1
Is, for example, a wide tunnel A for highways (see FIG. 5).
In the excavation process of (d) right side), a plurality of tunnels having a circular cross section are used for excavating a tunnel (arcuate tunnel) D that partially overlaps and is continuous in an arc shape. Prior to the excavation work of the bow-shaped tunnel D, a circle having a large diameter is formed by a known hard rock tunnel excavator (not shown) equipped with hard rock cutter disks at positions corresponding to both sides of the tunnel A. The auxiliary tunnels B of the cross section are respectively excavated in parallel (Fig. 5
(a)). Then, in the auxiliary tunnel B, as shown in FIGS. 1 and 2, concrete having a thickness of about half the diameter of the tunnel is poured to form a side wall C (FIG. 5 (b)).

An arcuate tunnel D is excavated while advancing the tunnel excavator 1 using the opposing inclined walls C1 formed at the upper ends of the concrete side walls C on both sides as a guide (FIG. 5 (c)). In this tunnel excavator 1, in this example, a space in which five cylindrical shield portions are partly overlapped and integrated to communicate with each other, that is, five circles overlap each other in an arc shape so that five circles overlap each other. Shield with open cross section space
And a shield excavator main body 2 provided with the excavator main body 2 and five excavating means 5 mounted on the front end portion of the excavator main body 2 while being alternately displaced in the front-rear direction. The excavation means 5 includes a cutter disk 7 in which a large number of roller cutters 7a are rotatably arranged as shown in FIG.
The ring gear 9 is rotatably disposed in front of the outer peripheral support.
This is a structure in which the cutter disk 7 is rotated by the drive motor 9 disposed on the upper side via a.

As shown in FIGS. 2 and 3, a front gripper 11 that projects outward in the radial direction is provided at an appropriate position just behind the cutter disk 7 of the cylindrical shield 6, and these fronts are provided. The cutter disk 7 is formed by projecting the gripper 11 and pressing it against the excavation surface.
The cylindrical shield 6 is held in place during the rotation of, and the cutter disk 7 is prevented from swinging. Below the central portion of the bottom surface of the shield 6, the sled 1 extending in the longitudinal direction is provided.
0 is attached, and the sled 10 slidably supports the excavator main body 2 in the excavation hole (excavation diameter by the cutter disk 7) larger than the outer diameter of the shield 6. Further, a frame body 12 having a rectangular cross section is integrally extended rearward from the central portion of the partition wall 8, and a frame body 22 having a rectangular cross section with an inner opening slightly larger than the frame body 12 is formed in the excavator main body 2.
The frame 12 on the side of the excavation means 5 is slidably fitted in the frame 22 provided on the side.

The frame 22 on the main body 2 side of the excavator is pivotally attached via a pivot shaft 24 to a support frame 23 whose front portion on the lower surface side is fixed to each shield portion 3a, and a rear end of the lower surface of the frame body 22. Pitching jack 25 between the bottom and the bottom of the shield 3a.
Is installed. Therefore, by expanding and contracting the pitching jack 25, the frame body 2 is supported with the pivot shaft 24 as a fulcrum.
The front side of 2 is swung in the vertical direction. Between the middle part of the frame body 22 and the rear end part of the frame body 12, two on each side (total of 4
The thrust jack 26 of FIG. 3 is interposed, and the thrust jack 26 is contracted from the state shown in FIG. 3 so that the excavation means 5 (cylindrical shield 6 and cutter disk 7) can move the thrust jack 26 to the excavator body 2 at the maximum. Move forward by 26 strokes.

As shown in FIG. 4, in order to discharge excavated rock and excavated earth and sand from the space (cutter chamber) 8a between the excavator 5 and the cutter disk 7 in front of the partition wall 8, first belt conveyor 27 is used. Is arranged behind the frame body 12 through the central portion of the partition wall 8 and the inside of the frame body 12. A soil outlet 27a is provided on the lower surface of the rear end of the first belt conveyor 27, and a second belt conveyor 28 is disposed below the soil outlet 27a in the front-rear direction of the excavator body 2. In this example, five first belt conveyors 27 and two second belt conveyors 28 are provided corresponding to the excavation means 5. On both sides of the excavator main body 2, a fourth belt conveyor 30 is arranged in the front-rear direction, and the fourth belt conveyor 30 extends from the lower rear end portion of the central second belt conveyor 28 to the upper front end portions of the left and right fourth belt conveyors 30. The three-belt conveyors 29, 29 are arranged in the width direction of the excavator main body 2, respectively. The third belt conveyor 29 inclines downward from the center to the side of the excavator body 2 as shown in FIG. 2, but in the present example, a belt conveyor 29a closer to the center and a belt conveyor 29b closer to the side are provided. Is divided into

As shown in FIGS. 2 to 4, an arch-shaped thrust support frame 31 is arranged above the rear portion of the shield 3, and one end of each shield jack 32 is attached to the thrust support frame 31. The other end of each shield jack 32 is directed rearward, and the other end of each shield jack 32 is made of an arch-shaped segment that is assembled near the rear end of the shield 3 when the excavator body 2 moves forward. It is brought into contact with the ceiling wall E. In this example, the ceiling wall E is divided into a plurality of segment pieces, and is erected from one upper end inclined portion C1 of the concrete side walls C on both sides to the other upper end inclined portion C1. The ceiling wall E is assembled by a dedicated erector (not shown) connected and arranged immediately behind the excavator body 2.

Further, in this example, the ceiling wall E is assembled in an arch shape in the arcuate tunnel D as close to the upper end as possible, and the lower part thereof is effectively used as the main tunnel A, so that a fan shape between the two circular section tunnel portions is formed. A plurality of auxiliary excavation means 41 for excavating the bedrock portion are provided. These auxiliary excavation means 41 are laterally arranged at both sides of the rear portion of the shield 3 and between the arcuate shield portions 3a. Each auxiliary excavation means 41 includes a small cylindrical cutter drum 42 which is exposed to the outside of the shield 3 and is rotatably disposed, and a drive device 43 which is installed in the shield 3 and rotates the cutter drum 42. Therefore, a large number of roller cutters 42a for crushing are mounted on the outer peripheral surface of the cutter drum 42. In addition, an intake port 44 for excavating rock or the like is opened in the shield 3 below each drum 42, and a belt conveyor 45 is provided below the intake port 44 and the second belt conveyor 2 is provided.
8 is arranged in parallel.

The hard rock tunnel excavator 1 according to the first embodiment of the present invention is constructed as described above. The excavation mode of the tunnel excavator 1 will be described below with reference to FIG.

As described above, prior to the excavation work of the arcuate tunnel D, the auxiliary tunnels B having a large diameter and having a circular cross section are excavated in parallel at positions corresponding to both sides of the main tunnel A (see FIG. 5 (a)). )). Subsequently, a concrete side wall C having a thickness approximately half the inner diameter thereof is formed in the auxiliary tunnel B (FIG. 5 (b)). The tunnel excavator 1 has a sloped wall C formed at the upper ends of concrete side walls C on both sides.
1 and the mine wall excavated by the cutter disk 7 are used as guides to intermittently move forward by a constant distance.

That is, while the excavator main body 2 is stopped at a fixed position, the cutter disks 7 of the excavating means 5 are simultaneously rotated, and at the same time, the front gripper 11 of the cylindrical shield 6 is pushed and held against the excavating surface. While excavating the arcuate tunnel D (on the left side in FIG. 5C), the thrust jack 26 is contracted and the excavation means 5 is advanced according to the excavation situation. In this way, while all the excavating means 5 have advanced to the foremost position with respect to the excavator body 2, the rotation of each cutter disk 7 is temporarily stopped, and the shield jack 3 at the rear portion is stopped.
The excavator main body 2 is pushed back to the front side of the excavating means 5 by abutting the segment ceiling wall E on the segment 2 and extending the segment ceiling wall E. Further, when the excavator main body 2 moves forward, the cutter drums 42 of the auxiliary excavating means 41 at the rear are simultaneously rotated to excavate and remove the fan-shaped rock portion D ′ remaining between the tunnels having the circular cross section (FIG. 5). (c) Right side).

After that, the shield jack 32 is contracted,
An arch-shaped ceiling wall E is assembled in a space with the existing segment-made ceiling wall E by a plurality of segment pieces (FIG. 5 (d) left side). Further, the bow-shaped tunnel D is excavated by the front excavating means 5 in the above-described manner.

The rock mass excavated by the cutter disk 7 of each excavation means 5 is crushed by the roller cutter 7a on the front side and taken into the cutter chamber 8a as a small lump of excavated piece. From there, it is conveyed by the first belt conveyor 27 into the excavator main body 2 and then discharged to the rear of the tunnel excavator 1 through the second belt conveyor 28, the third belt conveyor 29, and the fourth belt conveyor 30 in this order. It In addition, the fan-shaped rock portion D ′ excavated by each auxiliary excavation means 41 is crushed by the roller cutter 42a on the peripheral surface when the drum 42 rotates, and is formed as a small lump of excavated material on the belt conveyor 45 below the intake port 44. The third belt conveyor 29 after being dropped and taken in
Then, it is discharged to the rear of the tunnel excavator 1 through the fourth belt conveyor 30 in order.

As described above, the concrete side walls C on both sides and the arch-shaped concrete ceiling wall E between the upper end inclined portions C1 are formed. Then, a part of the auxiliary tunnel B and a part of the arcuate tunnel D are already formed as a part of the main tunnel A below the area surrounded by the walls C and E, so that the unexcavated portion F (see FIG. 5) is formed. (d) Left side) is relatively small. Moreover, since collapse prevention processing of the excavation surface is not necessary, the wide tunnel A can be completed in a short period of time by excavating the unexcavated portion F with, for example, a small hard rock excavator (not shown) (Fig. 5 (d) right side).
Reference numeral G in FIGS. 1 and 2 indicates the road pavement portion of the main tunnel A.

Although one embodiment has been introduced above, the present invention can also be carried out as follows.

A) In the above embodiment, in order to utilize the arcuate tunnel D as a part of the main tunnel A as effectively as possible, a plurality of auxiliary excavation means 41 for excavating the fan-shaped rock portion D'between the two tunnels of circular cross section. However, it is not limited to the tunnel excavator 1 including the auxiliary excavation means 41.

B) As shown in FIG. 6 (b), hard rock tunnel excavating means 5'having substantially the same structure as the excavating means 5 are provided at the front end of the excavator main body 2'at regular intervals. It is arranged to be swingable. The excavating means 5'is three units, and the central excavating means 5'is horizontally swingably arranged as shown in FIG. 6 (a).
The excavating means 5'on both sides are arranged so as to be swingable in a direction inclining slightly upward toward the center. Correspondingly, the front end of the excavator main body 2'is formed into a shape in which three arcs are connected from above, and the direction of each arc is horizontal, with the sides centered slightly upwards. Incline.

As shown in FIG. 7B, the swing tunnel excavator 1'of the present embodiment having the above-described structure has a frame 2 on the main body side.
2 is supported on the upper and lower surfaces of the shield 3 via a support shaft 53 so as to be swingable in the width direction of the arcuate tunnel D (FIG. 5C). The support shaft 53 is rotatably supported by a bearing 54. Then, a rocking jack 58 is provided between the rear end of the frame body 22 and the excavator main body 2 ′ side.
Due to the expansion and contraction, the frame body 22 rotates in the width direction of the tunnel with the support shaft 53 as a fulcrum. Each excavation means 5'includes a frame body 12 extending rearward from the partition wall 8 as in the first embodiment.
Since it is supported by the excavator body 2 by being slidably fitted in the excavator 2, the excavation means 5 ′ is swung by the expansion and contraction of the swing jack 58.

The excavation of the arcuate tunnel D by the rocking tunnel excavator 1'of this example is performed by the following two methods.

Cutter disc 7 of each excavation means 5 ′
Is rotated, the thrust jack 26 is slightly contracted to slightly advance the cutter disk 7, and then the swing jack 58 swings the tunnel disc in the width direction of the tunnel so that the three tunnels having an oval cross section continue in an arc shape. Excavate the bow tunnel D. Since the other excavation work is the same as that of the first embodiment described above, its explanation is omitted.

After the orientation of each excavating means 5 ′ is determined by the swinging jack 58, the thrust jack 26 is gradually contracted to the stroke end while rotating the cutter disk 7. The thrust jack 26 is extended to return the cutter disk 7 to the original position, the direction of each excavating means 5'is changed by the swing jack 58, and the thrust jack 26 is gradually rotated to the stroke end while rotating the cutter disk 7 again. Contract. An oval tunnel is excavated by repeating this operation several times. Since the other excavation work is the same as that of the first embodiment described above, its explanation is omitted.

C) As shown in FIGS. 8 (a) and 8 (b), a pair of small excavating means 5 ″ having a cutter disk 7 at the tip of a cylindrical shield 6 is attached to the front end of the excavator body 2 ″. It is placed in an arch shape so that it can move freely. One of the excavating means 5 "is moved from the center of the excavator body 2" to the right side, and the other excavating means 5 "is moved from the center of the excavator body 2" to the left side so as to face each other. The shield 3 ″ of the excavator main body 2 ″ has a cross-sectional shape corresponding to the arched tunnel D excavated by the pair of excavation means 5 ″.

As shown in FIG. 9 (a), the excavation means 5 "is moved by an arched rack 61 provided at the front end of the excavator main body 2" and a pinion meshed with the rack 61. There is one in which the excavation means 5 ″ is equipped with 62 and the pinion 62 is rotated to move the excavation means 5 ″ along the rack 61.

Alternatively, as shown in FIG. 9 (b), an arch-shaped stair rack 63 is arranged at the front end of the excavator main body 2 ", and one end of each of the plurality of telescopic jacks 64 and 65 is excavated. Pivotally connected to means 5 ". Then, the one jack 64 is contracted to engage the other end of the jack 64 with the step portion 63a with which the jack 65 is engaged. In this state, the two jacks 64 and 65 are simultaneously extended to move the excavation means 5 ″ along the rack 63 in an arch shape. Here, by contracting one jack 65, the other end is moved. Further, it engages with the upper stepped portion 63b. Since this state is the same as that shown in Fig. 9 (b), the excavation means 5 "is moved in an arch-like shape by repeating the above operation. You can

D) As shown in FIG. 10 (b), a pair of excavating means 5 "are provided at the front end of the excavator main body 2" so as to be movable in an arch shape in a posture in which the excavating means 5 "face each other and are inclined forward and sideways. To deploy. Then, as shown in FIG. 10 (a), the two excavating means 5 ″ are moved so as not to interfere with each other, and one excavating means 5 ″ excavates a half of the arcuate tunnel D.
The other half of the arcuate tunnel D is excavated by the other excavation means 5 ". The excavation means 5" can be moved by moving the excavation means 5 "in FIG.
Alternatively, the method (b) can be used.

E) As shown in FIG. 11 (b), at the front end of the excavator main body 2 ", a pair of excavation means 5" are held laterally facing each other and are movable in an arch shape. Deploy. Then, as shown in FIG. 11A, the two excavating means 5 ″ are moved so as not to interfere with each other, and one half of the arcuate tunnel D is excavated by one excavating means 5 ″, and then the other excavating means 5 ″. The other half of the arcuate tunnel D is excavated by means of the method of moving the excavation means 5 "by the method shown in Fig. 9A or 9B.

[0039]

As is apparent from the above description,
The bow tunnel excavator for hard rock of the present invention has the following effects.

(1) In the tunnel excavator according to claim 1, the excavation work can be performed while the collapse of the ground is stopped by the shield of the excavator body, and the arched ceiling wall can be assembled within the shield shield. Is safe, and the lock bolt used in the NATM method is completely unnecessary. Therefore, when a wide tunnel is excavated using the tunnel excavator of the present invention, the working environment is better than the excavation work by blasting, the safety of the whole work is excellent, and the work efficiency is high, and the unit period The excavation distance per tunnel is greatly extended, and the excavation period is considerably shortened.

(2) The tunnel excavator according to claim 2 has substantially the same effect as the excavator according to claim 1, and the number of tunnel excavating means can be reduced as compared with the tunnel excavator according to claim 1.

[0042]

[Brief description of drawings]

FIG. 1 is a front view showing an outline of a hard rock bow tunnel excavator as a first embodiment of the present invention.

2 is a rear view of the tunnel excavator of FIG. 1, II of FIG.
It is a II sectional view.

FIG. 3 is a plan view in which a part of the tunnel excavator of FIG. 1 is cut away.

4 is a sectional view taken along line IV-IV in FIG.

5 (a) to 5 (d) are schematic front views sequentially showing a process of excavating a wide main tunnel A using the tunnel excavator of the first embodiment of the present invention.

FIG. 6 (a) is a front conceptual view showing an excavation mode of an arcuate tunnel by a tunnel excavator as a second embodiment of the present invention, and FIG. 6 (b) is a tunnel excavator as a second embodiment. It is a top view which shows an outline.

7 (a) is a plan view of one excavating means of a tunnel excavator as a second embodiment of the present invention, and FIG. 7 (b) is FIG.
It is the VII-VII sectional view taken on the line of (a).

FIG. 8 (a) is a front conceptual view showing an excavation mode of an arcuate tunnel by a tunnel excavator as a third embodiment of the present invention, and FIG. 8 (b) is a tunnel excavator as a second embodiment. It is a top view which shows an outline.

FIG. 9 (a) is a front view showing a part of a moving method of one excavating means of a tunnel excavator as a third embodiment of the present invention, and FIG. 9 (b) is another moving method of the excavating means. It is a front view which shows a part of system.

FIG. 10 (a) is a front conceptual view showing an excavation mode of an arcuate tunnel by a tunnel excavator as a fourth embodiment of the present invention, and FIG. 10 (b) is a tunnel excavator as a fourth embodiment. It is a top view which shows an outline.

11 (a) is a front conceptual view showing an excavation mode of an arcuate tunnel by a tunnel excavator as a fifth embodiment of the present invention, and FIG. 11 (b) is a tunnel excavator as a fifth embodiment. It is a top view which shows an outline.

[Explanation of symbols]

1 tunnel excavator 2 excavator body 3 shield 5.5'5 'excavation means 6 Cylindrical shield 7 Cutter disc 8 partitions 9 Drive motor 11 Front gripper 12.22 frame 26 Thrust jack 27-30 Belt conveyor 31 thrust support frame 32 shield jack 41 Auxiliary excavation means 42 cylindrical drum A wide book tunnel B auxiliary tunnel D bow-shaped tunnel

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-2-24485 (JP, A) JP-A-4-85500 (JP, A) JP-B-55-7914 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) E21D 9/08

Claims (2)

(57) [Claims] 1. A shield having a plurality of circular cross-section openings partially overlapped with each other and continuously arranged in an arc shape, and integrated with each other to communicate the inside thereof, wherein the shield has an arc-shaped thrust support frame and the thrust. An excavator main body having a plurality of shield jacks, one end of which is attached to a support frame and which is telescopically driven rearward, and a front end portion of the excavator main body, which are alternately arranged in a front-rear direction and are arranged in a series of arcs, respectively. A plurality of hard rock tunnel excavating means, which are arranged so as to be movable back and forth with respect to the excavator body via a thrust jack, and which are provided with a hard rock cutter disk and a cylindrical or substantially cylindrical shield following the hard rock, A bow-shaped tunnel excavator for hard rock, comprising: 2. A circular cross section is continuously moved in an arc shape.
A shield or multiples communicating through the interior of the arcuate opening formed
A part of the arcuate opening is overlapped and continuously arranged in an arcuate shape, and is integrally provided with a shield communicating with the inside,
An excavator main body provided with an arc-shaped thrust support frame inside this shield, and a plurality of shield jacks that are attached to this thrust support frame at one end and extend and retract rearward, and at the front end of this excavator main body, the front face of the tunnel. The excavator further comprises a hard rock tunnel excavating means which is arranged so as to be reciprocally movable in an arch shape and includes a hard rock cutter disk and a cylindrical or substantially cylindrical shield following the hard disk cutter disk. Arched step rack at the front end of the main body
(63) is provided, and a plurality of telescopic jacks (64)
One end of (65) is pivotally attached to each of the hard rock tunnel excavation means.
Then retract one of the jacks (64) to
Jack to the step (63a) with which the key (65) is engaged.
Engage the other end of (64), and in this state,
By extending Ki (64) and (65) at the same time,
The hard rock tunnel excavation means along the rack (63)
Move in an arch, where one of the jacks (6
5) By contracting the other end,
The above operation of engaging the difference portion (63b) is repeated.
By doing so, the hard rock tunnel excavation means is arched.
A bow-shaped tunnel excavator for hard rock, characterized by being moved .