JP3210618B2 - Method of forming tunnel support - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a support body for supporting a rock excavation wall surface excavated by a tunnel excavator.

[0002]

2. Description of the Related Art When a tunnel is excavated by a tunnel excavator, the excavated tunnel wall surface may fall off or fall down. A ring-shaped support made of H-section steel is assembled along with a lining member such as expanded metal or a wire mesh between the adjacent ring-shaped supports, and is loosened from the tunnel wall surface in the tunnel by the lining member. It forms a shoring that prevents the rock mass from collapsing.

[0003]

However, according to the above-mentioned prior art, since the assembling of the shoring is performed behind a tunnel excavator in which the excavated tunnel wall surface is exposed, a ring-shaped shoring member is required. There is a risk that the bedrock may collapse when assembling or stretching the lining member, which is extremely dangerous and that the work cannot be performed smoothly. For this reason, a rectangular frame formed by stretching a wire mesh body on a rectangular steel frame curved in an arc shape in the circumferential direction of the tunnel is connected circumferentially in the skin plate of the tunnel excavator to form a ring-shaped support body. After assembling, a method of forming a support by sending it to the tunnel excavation wall side has also been proposed.However, since the ring-shaped support body assembled in the skin plate has a smaller diameter than the tunnel excavation wall side, it has been proposed. A gap will be created between the support body and the tunnel excavation wall surface when it is sent out. Such a problem also occurs in the case of a small-diameter ring-shaped support assembled in a tunnel. Therefore, in order to fill the gap, it is necessary to re-form the ring-shaped support body to have a large diameter. However, at present, no specific means for implementing this has been found.

[0004] The present invention has been made in view of such problems, and an object of the present invention is to provide a small-diameter ring-shaped support body assembled in a tunnel excavator so as to reliably prevent the rock from falling off from a loosened portion of rock. It is another object of the present invention to provide a method of forming a support body capable of easily and accurately expanding the diameter while preventing the tunnel excavation wall surface entirely.

[0005]

According to a first aspect of the present invention, there is provided a method for forming a tunnel support body, comprising: a plurality of rectangles curved in a tunnel circumferential direction in a skin plate of a tunnel excavator; When a small-diameter ring-shaped support body composed of a frame-shaped support piece is assembled, when the rear side of the small-diameter ring-shaped support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall surface side, the small-diameter ring is supported. The rear end of the ring-shaped support is pushed up to bring the upper peripheral portion into contact with the upper peripheral wall of the tunnel excavation wall surface. In this state, the diameter of the small-diameter ring-shaped support is increased on the rear side, and the rear outer peripheral surface is tunneled. When the front side of the small-diameter ring-shaped support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall side, the small-diameter ring is supported. The small-diameter ring-shaped support is expanded by pushing up the front end side of the ring-shaped support so that the upper peripheral portion thereof is in contact with the upper peripheral wall of the tunnel excavation wall. The outer peripheral surface of the body is brought into full contact with the tunnel excavation wall surface.

According to a second aspect of the present invention, a small-diameter ring-shaped support body composed of a plurality of rectangular frame-shaped support pieces curved in the tunnel circumferential direction is assembled in a skin plate of a tunnel excavator, and the small-diameter ring-shaped support body is assembled. When the rear side of the support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall side, the rear end side of the small-diameter ring-shaped support body is pushed up, and the upper periphery thereof is formed on the tunnel excavation wall surface. When the front side of the small-diameter ring-shaped support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall side, the small-diameter ring-shaped support is brought into contact with the upper peripheral wall. The front end side of the body is pushed up to bring the upper peripheral surface of this small-diameter ring-shaped support body into contact with the upper peripheral wall portion of the tunnel excavation wall surface over the entire length. It is expanded the ring-shaped 支保 body, characterized in that to fully contact the outer peripheral surface thereof to the tunnel excavation wall surface.

According to a third aspect of the present invention, in the first or second aspect of the invention, a part of the upper and lower support pieces constituting the small diameter ring-shaped support body can be separated in the circumferential direction. The small-diameter ring-shaped support body is expanded by being relatively sent out from the skin plate of the tunnel excavator to the tunnel excavation wall surface side and separating the small-diameter ring-shaped support body from the joint portion in the circumferential direction. The outer peripheral surface is brought into contact with the tunnel excavation wall surface.

According to a fourth aspect of the present invention, there is provided a method for forming a tunnel support body different from the first or second aspect, wherein a plurality of rectangular frames curved in the circumferential direction of the tunnel in the skin plate of the tunnel excavator. By connecting the support pieces along the both sides from the upper peripheral portion of the skin plate, a small-diameter support having a C-shaped cross section with a downward opening is assembled, and the rear side of the small-diameter support is tunneled from the rear end of the skin plate of the tunnel excavator. When the small-diameter support body is relatively fed to the excavation wall side, the rear end side of the small-diameter support body is pushed up to bring the upper peripheral portion into contact with the upper peripheral wall portion of the tunnel excavation wall surface. When the part side is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall side, the front end side of the small-diameter support body is pushed up to extend the upper peripheral surface of the small-diameter support body to the entire length. A small diameter ring-shaped support body is formed by assembling the lower peripheral side support piece between the lower ends of both side support pieces of the small diameter support body while maintaining this state. The small-diameter ring-shaped support body is expanded in diameter, and its outer peripheral surface is entirely brought into contact with the tunnel excavation wall surface.

In the above method of forming a tunnel support,
As described in claim 5, the small diameter ring-shaped support body push-up means is provided with a small diameter ring-shaped support body or a downwardly directed one on a sliding frame which can reciprocate back and forth between a skin plate of a tunnel excavator and a tunnel excavation wall surface. The expansion means of the small-diameter ring-shaped support body is constituted by a push-up jack which is mounted with an interval between the front and rear ends of the C-shaped support body having a cross-section opened therein.
As described above.

[0010]

The small-diameter ring-shaped support body can be formed by connecting a plurality of support pieces curved in an arc shape in the direction along the tunnel excavation wall surface in the tunnel circumferential direction.
The assembly of the small-diameter ring-shaped support is performed in the rear end of the skin plate of the tunnel excavator. At this time, on one side of the lower half of the small-diameter ring-shaped support body, a vertically adjoining support piece is formed as a joinable portion that can be separated without being integrally connected. Next, the assembled small-diameter ring-shaped support is sent from the rear end of the skin plate to the tunnel excavation wall side excavated by the excavation of the tunnel excavator. When it is sent out, the rear end side is pushed up to bring its upper peripheral portion into contact with the upper peripheral wall portion of the tunnel excavation wall surface.
Then, the rear end side of the small-diameter ring-shaped support body rises from the bottom surface of the tunnel excavation wall surface, and is deformed into a side parallelogram inclined obliquely upward from the front end toward the rear end.

From this state, when the rear end side of the joint portion of the small-diameter ring-shaped support that is separably joined is expanded in the circumferential direction using an expansion jack or the like, the small-diameter ring-shaped support is moved from the front end to the rear end. The diameter of the rear end of the ring-shaped support body increases in a tapered shape toward the entire surface of the tunnel excavation wall. Next, when the front half of the small-diameter ring-shaped support body is sent out from the rear end of the skin plate to the tunnel excavation wall side, the front end side is pushed up in the same manner as described above, and the upper periphery thereof is brought into contact with the upper peripheral wall of the tunnel excavation wall. After making contact, the front end side of the joint that is separably joined is expanded in the circumferential direction to expand the front half, so that the entire outer peripheral surface of this small diameter ring-shaped support body abuts the tunnel excavation wall surface It is formed on the expanded ring-shaped support body. In addition, the step of expanding the diameter at the front and rear end sides of the small-diameter ring-shaped support body may be performed sequentially after the entire small-diameter ring-shaped support body is sent out from the skin plate to the tunnel excavation wall surface side, as described in claim 2. Good.

As described above, a small-diameter ring-shaped support is assembled in the skin plate of the tunnel excavator, and this ring-shaped support is sent out to the tunnel excavation wall side, and its upper peripheral portion is formed on the upper peripheral wall of the tunnel excavation wall. Since the diameter is expanded in the abutted state, it is possible to safely and efficiently assemble the ring-shaped support body from the work of assembling the ring excavation wall without being affected by the collapse of the rock on the wall of the tunnel excavation In addition, it is possible to perform the diameter expansion work with the rear end face of the ring-shaped support body being in contact with the front end face of the expanded ring-shaped support body already constructed on the tunnel excavation wall surface. It is possible to accurately and efficiently form a support consisting of a series of expanded ring-shaped supports supporting the entire surface of the tunnel excavation wall. When the ring-shaped support body is sent out to the tunnel excavation wall side, there is almost no gap between the upper peripheral wall surface of the tunnel excavation wall surface and the outer peripheral surface of the ring-shaped support body. It can be safely performed while preventing collapse and skin fall from the loosened part of the rock.

According to the fourth aspect of the present invention, the C-shaped small-diameter support member having a downward opening in which no support piece on the lower peripheral side of the ring-shaped support member is provided in the skin plate is assembled. Then, the small-diameter support is sent out from the rear end of the skin plate to the tunnel excavation wall side and pushed up when the rear side and the front side are sequentially sent out, and the upper periphery of the small-diameter support is extended to the upper periphery of the tunnel excavation wall. Since it is to be brought into contact with the wall surface, the skin plate side with almost no gap between the tunnel excavation wall surface and the upper peripheral portion of the small-diameter support body as in the invention according to claim 1 or 2. From the tunnel excavation wall directly from the skin plate. It is intended.

Further, after being sent out to the tunnel excavation wall surface side, the lower peripheral side support piece is incorporated between the lower ends of both side support pieces in the small diameter support body having the downward opening to form a small diameter ring-shaped support body. From the above, the small diameter ring-shaped support body can be safely assembled and the small diameter ring-shaped support body can be safely assembled in a state in which the upper peripheral portion of the small diameter support body is brought into contact with the upper peripheral wall surface of the tunnel excavation wall to prevent collapse due to loosening of the rock. The work of expanding the diameter of the support body and bringing the outer peripheral surface into full contact with the tunnel excavation wall surface can also be performed smoothly.

Further, in any of the above-described methods for forming the tunnel support, the assembling speed of the small-diameter ring-shaped support is significantly higher than the excavation speed of the tunnel length of one span of the small-diameter ring-shaped support by the tunnel excavator. Therefore, without exposing the tunnel excavation wall surface to the rear end side of the skin plate, it is possible to efficiently and smoothly perform the diameter expansion work from the delivery of the support body from the skin plate to the tunnel excavation wall surface.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a tunnel excavator according to a first embodiment of the present invention;
This shows a state in which the front and rear opposing surfaces are integrally supported on a tunnel excavation wall T excavated by a ring-shaped support body A ′, A ′... The support A 'is sequentially sent out from the small-diameter ring-shaped support A assembled in the skin plate 11 of the tunnel excavator 10 to the tunnel excavation wall T side behind the skin plate excavated by the tunnel excavator 10, which will be described later. It is formed by expanding the diameter by an expansion jack 5 which is a diameter expanding means and pressing it against the tunnel excavation wall surface T.

The tunnel excavator 10 has a support member 12 disposed integrally with the skin plate 11 at an opening at the front end of a cylindrical skin plate 11, and is supported by the support member 12 so as to be rotatable. A cutter plate 13 driven to rotate by a drive motor (not shown) mounted in the member 12
A beam member 14 which is integrally fixed to the front end of the support member 12 at the rear end thereof and extends horizontally rearward from the rear end of the skin plate 11 through the central space of the skin plate 11; A retractable front gripper 15 integrally mounted on the upper, lower, left and right sides of the support member 12, a rear support 16 projecting downward from the lower surface of the rear end of the beam body 14 and extending vertically by a jack 16a, and a beam body It comprises a rear gripper 17 slidably disposed along the lower surface of 14, and a propulsion jack 18 connecting the support member 12 and the rear gripper 17.

Further, a skin plate is attached to the beam member 14.
A sliding frame 3 capable of reciprocating back and forth between the inside of the tunnel excavation wall T and the inside of the tunnel excavation wall 11 is slidably fitted on the sliding frame 3, and a gap between the front and rear ends of the small-diameter ring-shaped support A on the sliding frame 3. The jacks 4a and 4b are mounted in an upright position.

The skin plate 11 has a beam member 14.
The rear gripper 17 is integrally fixed and supported on the outer peripheral surface of the beam body 14 via a connecting frame member 20, and the rear gripper 17 is disposed on the rear side of the beam body 14 projecting rearward from the skin plate 11. A beam receiver 19 which is slidable relative to the body 14 projects horizontally from both lower surfaces of the beam receiving surface T toward both side surfaces of the tunnel excavation wall T, and both rear grippers 17, 17 and both rear surfaces of the support member 12 The parts are connected by the propulsion jacks 18, 18, respectively. Further, the slide frame 3 and the beam receiver 19 are connected by a slide jack 21 so that the slide frame 3 is moved back and forth by the slide jack 21. The earth and sand excavated by the cutter plate 13 is supplied by a conveyor (not shown).
Is discharged backward by an appropriate carrying-out means such as

In the rear end of the skin plate 11 of the tunnel excavator 10 constructed as described above, first, as shown in FIG. Circular ring-shaped support body having a diameter smaller than the diameter of the tunnel excavation wall 2 and a rock fall prevention member 2 stretched on the outer peripheral surface of the upper half part by connecting the support pieces 1, 1A, 1B in the circumferential direction. Form A. Support piece 1
1B, as shown in FIGS. 7 to 9, the front and rear main girders 1a, 1b curved in an arc along the tunnel excavation wall surface T are integrally fixed by flat plate-shaped joint plates 1c, 1c. It consists of a rectangular steel frame. As shown in FIG. 7, the support piece 1 disposed along the upper peripheral wall portion of the tunnel excavation wall T is a rock fall made of a wire mesh in which bar-shaped metal wires are combined in a grid at the outer peripheral open end of the rectangular frame. It has a structure in which the prevention member 2 is stretched.

On the other hand, as shown in FIG. 9, the support piece 1B disposed along the lower peripheral wall, which is the bottom of the tunnel excavation wall T, is formed of a steel rectangular frame having no rock fall prevention member. . Further, as shown in FIG. 8, the support piece 1A provided between the upper and lower support pieces 1 and 1B and disposed along both side walls of the tunnel excavation wall T includes an upper half portion of a steel rectangular frame. Rock fall prevention member 2 'made of wire mesh
Is stretched. In addition, each support piece 1
Several bolt insertion holes 6a and 6b for connecting supporting pieces adjacent to each other in the tunnel length direction and the circumferential direction are drilled in the main girders 1a and 1b and the joint plate 1c of 〜1B.

In FIG. 4, the small-diameter ring-shaped support body A is formed from four support pieces. However, a small-diameter ring-shaped support body may be formed by combining four or more support pieces. In this case, the rock fall prevention member 2
Support piece 1 at the top and a rock fall prevention member 2
As the intermediate support piece 1A between the lowermost support piece 1B and the lower support piece 1B, the support piece with the rock-fall prevention member 2 and the support piece without the support are vertically combined. In some cases,

In order to assemble the small-diameter ring-shaped support body A in the skin plate 11 of the tunnel excavator 10 using the support pieces 1, 1A and 1B, first, a steel rectangular frame having no rock-fall prevention member 2 is stretched. The supporting piece 1B is disposed on the rear inner bottom surface of the skin plate 11 so that its bending direction is directed to the circumferential direction of the skin plate 11.

Next, the support pieces 1A, 1A for supporting both side walls of the tunnel excavation wall T are sequentially arranged along both sides in the skin plate 11, and the lower joint plate 1c is connected to the support pieces 1B. By joining the supporting pieces 1b to the front and rear main girders 1a and 1b of the supporting piece 1B,
After combining the front and rear main girders 1a, 1b of A, 1A in a state of being continuous in the circumferential direction, the joint portions of one of the joint plates 1c, 1c are joined so as to be separable in the circumferential direction, and the other is joined. The joint portions of the joint plates 1c, 1c are integrally connected by bolts and nuts 7 through bolt insertion holes 6b, 6b communicating with each other. Incidentally, one of the joint plates 1c may be temporarily fastened to each other by bolts and nuts 7 and then removed at the time of expansion.

Thereafter, the supporting pieces arranged on both sides
A support piece 1 for supporting the upper peripheral wall of the tunnel excavation wall T is interposed between the upper joint plates 1c, 1c of 1A, 1A, and the joint plates 1c, 1c of the support piece 1 on both sides are connected to the support pieces 1A, 1A. The bolt holes 6b, 6b, which are connected to the joint plates 1c, 1c, respectively, are fastened by bolts and nuts 7 to be integrally connected. Note that the joining and connecting work between the support pieces is performed using an erector (not shown) arranged in the skin plate 11.

Thus, a plurality of support pieces 1, 1A, 1B
Are successively joined and connected from the lower peripheral side to the upper peripheral part in the skin plate 11, so that the center is located below the center of the skin plate 11 and the support on the upper peripheral side as shown in FIG. A circular small-diameter ring-shaped support A having a gap between the outer peripheral surface of the piece 1 and the inner peripheral surface of the upper surface of the skin plate 11 and having a radius smaller than the radius of curvature of the skin plate 11 is assembled. When assembled in this manner, the rock-fall prevention members 2, 2 ', which are stretched over the support pieces 1, 1A disposed on the upper and both sides, respectively, are connected to each other, and the upper half of the outer peripheral surface of the small-diameter ring-shaped support A is connected. Is covered.

In this way, the small-diameter ring-shaped support A can be assembled in the skin plate 11, and at least the rear half of the small-diameter ring-shaped support A can be disposed behind the skin plate 11 by excavating the tunnel excavator 10. When a tunnel of a certain length is excavated, the sliding frame 3, which has been waiting behind the skin plate 11 when the small-diameter ring-shaped support A is assembled, is extended by the slide jack 21 so that the small-diameter ring-shaped support A is extended.
The rod ends are made to advance into the inside and the jack ends 4a and 4b are extended to extend the rod ends thereof into small-diameter ring-shaped support bodies A.
The entire small-diameter ring-shaped support body is lifted up in a state of being separated from the inner peripheral surface of the skin plate 11 by making contact with the inner surfaces of the upper ends of the front and rear main girders 1a and 1b, respectively, and further pushing up.

In this state, the slide frame 3 is retracted by contracting the slide jack 21 and the rear half of the small-diameter ring-shaped support A is sent out from the skin plate 11 to the tunnel excavation wall T side. As shown in FIG. 5, the upper peripheral portion of the small-diameter ring-shaped support A is extended by further extending the rear push-up jack 4b in a state in which it is brought into contact with the front end face of the existing enlarged-diameter ring-shaped support A '. It is brought into contact with the upper peripheral wall surface of the tunnel excavation wall surface T. In this state, the small-diameter ring-shaped support A is deformed into a parallelogram having a side surface inclined obliquely upward from the front end toward the rear end, as shown in FIGS. The lower end of the small-diameter ring-shaped support body A may be slid in contact with the lower end of the skin plate 11 as shown in FIG.

Thereafter, the rear end side between the joint plates 1c, 1c detachably joined in the small-diameter ring-shaped support A is expanded in the circumferential direction by the expansion jack 5, so that the small-diameter ring-shaped support A is expanded. The diameter is increased in a tapered shape from the front end to the rear end, and the enlarged rear end is brought into close contact with the tunnel excavation wall surface T as shown in FIG. Next, when the front half of the small-diameter ring-shaped support body A is relatively sent out from the rear end of the skin plate 11 to the tunnel excavation wall T according to the excavation of the tunnel excavator 10, the front push-up jack 4a is further extended to reduce the small diameter. The upper peripheral portion of the ring-shaped support body A is brought into contact with the upper peripheral wall surface of the tunnel excavation wall T as shown in FIG. 3, and the front end between the joint plates 1c, 1c, which is detachably joined while maintaining this state. The side is pushed and expanded in the circumferential direction by the expansion jack 5.

Then, the entire small-diameter ring-shaped support body is expanded to the same diameter, and the entire outer peripheral surface is brought into contact with the tunnel excavation wall surface T, thereby forming a large-diameter ring-shaped support body A 'supporting the tunnel excavation wall surface T. You. The rear end face of the expanded ring-shaped support A 'and the existing expanded ring-shaped support A' are fastened with bolts and nuts between the bolt insertion holes 6a, 6a of the front and rear main girders 1a, 1b joined to each other. Thereby, they are integrally connected in the length direction of the tunnel. In this connection work, when the rear end side of the small-diameter ring-shaped support A was expanded, the rear main girder 1b was connected to the front main girder 1a of the existing enlarged-diameter ring-shaped support A 'by bolts. The insertion holes 6a, 6a may be fastened with bolts and nuts, and then the work of expanding the diameter of the front half of the small-diameter ring-shaped support body A may be performed.

In the above embodiment, each time the rear half and the front half of the small-diameter ring-shaped support A are relatively sent out to the tunnel excavation wall T side, the respective parts are pushed up and expanded. Each time the second half and the first half of the small-diameter ring-shaped support body A are relatively sent to the tunnel excavation wall T side, the respective parts are pushed up, and then, the small-diameter ring-shaped support body A is pushed up. The work of expanding the small-diameter ring-shaped support A may be performed with the upper peripheral portion of the small-diameter ring-shaped support A, which comes into contact with the peripheral wall surface by lifting, as a fulcrum.

The connecting structure of the connecting portion by the expansion jack 5 includes an inner peripheral surface at one side end of the front and rear main girders 1a and 1b of the lower support piece 1B disposed along a lower peripheral wall of the tunnel excavation wall T. Screw holes 8a, 8b for mounting brackets are provided on the inner peripheral surfaces of the opposite ends of the front and rear main girders 1a, 1b of the support pieces 1A, 1A on both sides, which are disposed along the peripheral wall portions on both sides of the tunnel excavation wall T. 8 and 9), and brackets 9a and 9b are removably fixed to these screw holes 8a and 8b by bolts, and then vertically opposed at one side lower portion of the small-diameter ring-shaped support body A. Bracket
The expansion jack 5 is interposed between the brackets 9a and 9b so as to be detachably mounted on the brackets 9a and 9b. In addition,
The mounting of the expansion jack 5 may be performed before sending out the small-diameter ring-shaped support A to the tunnel excavation wall T side when the small-diameter ring-shaped support A is assembled in the skin plate 11.

When the expansion jack 5 is extended to extend in the circumferential direction between the lower joints on one side of the small-diameter ring-shaped support A as described above, the push-up jacks 4a and 4b allow the upper peripheral wall of the tunnel excavation wall T to be formed. With the upper peripheral portion of the pressed small-diameter ring-shaped support body A as a fulcrum, the outer peripheral surface of the small-diameter ring-shaped support body A that is deformed in the radially expanding direction and separated inward from the tunnel excavation wall surface T is the tunnel excavation wall surface. T
To form the above-described expanded ring-shaped support A ′. In this way, the joint plates 1c, 1c separated by expansion are connected to each other by bolts and nuts 7 'between the opposing bolt insertion holes 6b, 6b.

Although the expansion jack 5 is used as the expansion means in the above embodiment, the expansion jack may be replaced by a push bolt. That is, bolts are threaded through the front and rear ends of the both-side joint plate 1c of the lower support piece 1B, and the front and rear ends of the front and rear bolts are sequentially sent out from the skin plate 11 by the rear half and the front half of the small-diameter ring-shaped support A. The two supporting pieces 1A, 1A facing the joint plate 1c
The bolts may be sequentially expanded by rotating the bolts in the screwing direction with the bolts being received on the end surfaces of the joint plates 1c. In this case, after the expansion, it is not necessary to connect the separated joint plates 1c, 1c with the bolts and nuts as described above, and the expanded diameter expanded ring-shaped support body A 'is maintained in the expanded state by the push bolt. You can keep.

When the work of expanding the small-diameter ring-shaped support A is completed, the slide jack 21 is extended to move the slide frame 3 into the next small-diameter ring-shaped support A assembled in the skin plate 11, The small-diameter ring-shaped support body A is pushed up and sent out to the tunnel excavation wall surface T while being lifted by the jacks 4a and 4b, and is expanded in the same manner as described above to form a large-diameter ring-shaped support body A 'for supporting the tunnel excavation wall surface T. Things.

The tunnel excavator 1 excavates the tunnel by pressing its rear grippers 17, 17 against both sides of the tunnel wall T, and then contracting the rear support 16 to separate it from the bottom of the tunnel wall 2, and thereafter. The front gripper 15 is excavated by the cutter plate 13 while sliding the front gripper 15 against the excavation wall surface 2 while the reaction force is supported on the tunnel wall surface 2 via the rear gripper 17 by extending the propulsion jack 18. After excavating a tunnel of a certain length, the front gripper 15 is firmly pressed against the excavation wall 2 and the rear support 16 is extended to be supported on the bottom surface of the excavation wall 2 and the rear gripper 17 is contracted.
The rear gripper 17 is advanced along the beam member 14 to the next crimping position by contracting 18.

Next, FIGS. 10 to 14 show another embodiment of the method for forming a tunnel support of the present invention. In the above embodiment, a ring-shaped support A having a small diameter was assembled in the skin plate 11. but assembled sectional C-shaped small diameter支保body a ₁ of the downward opening provided with no支保piece 1B of the lower peripheral portion side in the skin plate 11, the small diameter支保body a ₁ tunneling wall T
After delivery, the after forming the small-diameter ring-shaped支保body A by incorporating the lower peripheral portion side支保piece 1B under the peripheral portion of the small径支Hotai A _1, accordingly, increase the diameter of the small-diameter ring-shaped支保body A Things.

That is, first, the both side support pieces 1A, 1A are attached to the both side end joint plates 1c, 1c of the upper support piece 1 curved in the tunnel circumferential direction using an erector in the skin plate 11 of the tunnel excavator 10. By joining the upper joint plates 1c and 1c and integrally connecting them with bolts and nuts 7, FIG.
Assembling the C-shaped section diameter支保body A ₁ of the downward opening as shown in FIG. In addition, upper support piece 1 and support pieces 1 on both sides
The structures of the support pieces A, 1A and the lower support piece 1B used later are the same as the support pieces shown in FIGS.

The support of longitudinal main girder 1a small diameter支保body A _1, front and rear push-up jack 4a on sliding frame 3 which is disposed freely back and forth slide the upper end inner peripheral surface of the 1b to the beam member 14, by 4b In this state, the small-diameter support body A ₁ follows the excavation of the tunnel excavator 10.
When the rear half of the skin plate 11 is sent out from the rear end of the skin plate 11 to the tunnel excavation wall T side, the rear push-up jack 4b
The small diameter support body A ₁ is further raised as shown in FIG.
Is brought into contact with the upper peripheral wall of the tunnel excavation wall surface T. Then, when the front half portion of the small径支Hotai A ₁ according to excavation of the tunnel boring machine 10 is fed from the rear end of the skin plate 11 on the tunnel boring wall T side, by further raising the front side of the push-up jack 4b, this Small diameter support
Over the circumferential surface of the A ₁ over the entire length to being in contact with the top wall of the tunnel excavation wall T.

[0040] After accordingly, both sides支保piece 1A of the small-diameter支保body A ₁ While maintaining this state, the lower end fitting plate 1c of 1A, both side joint plate 1c of the lower支保piece 1B to 1c, bonding the 1c. At this time, as shown in FIG. 13, the joint portions of the one joint plates 1c, 1c are joined so as to be separable in the circumferential direction, and opposing inner peripheral surfaces of the front and rear main beams 1a, 1b of the support pieces 1A, 1B. Attach plackets 9a and 9b to these brackets 9
Install the front and rear expansion jack 5 between a and 9b. On the other hand, the joint portions of the other joint plates 1c, 1c are integrally connected by bolts / nuts 7 through bolt insertion holes 6b, 6b communicating with each other.

After assembling the small-diameter ring-shaped support body A in the tunnel excavation wall surface T, the upper peripheral portion of the small-diameter ring-shaped support body A is brought into contact with the upper and lower peripheral wall portions of the tunnel excavation wall T. Extending the expansion jacks 5, 5
As shown in FIG. 14, the small-diameter ring-shaped support body A is expanded to form a support body whose outer peripheral surface is entirely in contact with the tunnel excavation wall surface T as described above. Other configurations are the same as those shown in FIGS. 1 to 9 described above, and thus the same portions are denoted by the same reference numerals and description thereof will be omitted.

[0042]

As described above, according to the method for installing the support on the tunnel wall according to the first and second aspects of the present invention, a small-diameter ring-like support is assembled in the skin plate of the tunnel excavator. Therefore, it is possible to safely and efficiently assemble the small-diameter ring-shaped support body without being affected by any collapse or skin fall due to loosening of the rock on the wall of the tunnel excavation. When the rear half side and the front half side of the small diameter ring-shaped support body are sequentially sent to the tunnel excavation wall side from the rear end of the skin plate of the tunnel excavator, the rear end side and the front end side of the small diameter ring-shaped support body are Since the upper peripheral part is pushed up to make contact with the upper peripheral wall of the tunnel excavation wall, almost no gap is left between the tunnel excavation wall immediately after the skin plate and the outer peripheral surface of the small diameter ring-shaped support. Difference to the upper peripheral portion makes it possible to smoothly construction of the ring-shaped 支保 body for the tunnel excavation wall while preventing collapse and skin off of rock from the tunnel excavation wall immediately after skin plate without.

Further, the diameter of the small-diameter ring-shaped support body is expanded by expanding the front and rear ends of the small-diameter ring-shaped support body sent to the tunnel excavation wall surface side from the above-mentioned circumferentially separable joint. With the upper peripheral portion of the small-diameter ring-shaped support body abutting on the upper peripheral wall surface of the tunnel excavation wall as a fulcrum, the entire small-diameter ring-shaped support body can be expanded and brought into contact with the tunnel excavation wall surface. The diameter of the small-diameter ring-shaped support body is increased while the rear end face of the small-diameter ring-shaped support body is in close contact with the front end face of the existing enlarged-diameter ring-shaped support body. It is possible to surely block the tunnel and secure the safety of the operation in the tunnel.

According to the invention of claim 4, after assembling the C-shaped small-diameter support member having a downward opening having no support piece on the lower peripheral side of the ring-shaped support member in the skin plate, This small-diameter support is sent from the rear end of the skin plate to the tunnel excavation wall side, and when the rear side and the front side are sequentially sent out, the small-diameter support body is pushed up to the upper peripheral wall of the tunnel excavation wall. Since the abutment is made to abut, similar to the invention described in claim 1 or 2, the tunnel is formed from the skin plate side with almost no gap between the tunnel excavation wall surface and the upper peripheral portion of the small diameter support body. A small diameter support can be sent out to the excavation wall surface, so that it can be sent out while reliably preventing rock collapse and skin fall from the tunnel excavation wall surface immediately after the skin plate A.

Further, after being sent to the tunnel excavation wall surface side, the lower peripheral side support piece is incorporated between the lower ends of the both side support pieces in the small diameter support body having the downward opening to form a small diameter ring-shaped support body. From the above, the small diameter ring-shaped support body can be safely assembled and the small diameter ring-shaped support body can be safely assembled in a state in which the upper peripheral portion of the small diameter support body is brought into contact with the upper peripheral wall surface of the tunnel excavation wall to prevent collapse due to loosening of the rock. The operation of expanding the diameter of the support body and bringing the outer peripheral surface into full contact with the tunnel excavation wall surface can also be smoothly performed.

[Brief description of the drawings]

FIG. 1 is a simplified longitudinal side view of a tunnel excavator on which a ring-shaped support body is constructed,

FIG. 2 is a vertical sectional side view showing a state in which a rear end of a ring-shaped support sent out from a rear end of a skin plate of the tunnel excavator is lifted;

FIG. 3 is a simplified vertical sectional side view showing a state in which a rear end of a ring-shaped support sent out from a rear end of a skin plate of the tunnel excavator is lifted;

FIG. 4 is a simplified front view of a small-diameter ring-shaped support body assembled in a skin plate, a perspective view of a rectangular frame,

FIG. 5 is a simplified front view of a ring-shaped support body in which an upper peripheral portion is in contact with an upper peripheral wall surface of a tunnel excavation wall surface;

FIG. 6 is a simplified front view of a state where the diameter of the ring-shaped support body is expanded;

FIG. 7 is a perspective view of a support piece disposed at an upper part,

FIG. 8 is a perspective view of support pieces provided on both sides,

FIG. 9 is a perspective view of a support piece provided at a lower portion,

FIG. 10 is a simplified longitudinal side view of a tunnel excavator for explaining another method of forming a tunnel support body of the present invention;

FIG. 11 is a simplified front view of a state in which a small-diameter support body having a C-shaped cross section is assembled.

FIG. 12 is a simplified front view of a state in which a small-diameter support body is in contact with an upper peripheral wall surface of a tunnel excavation wall surface,

FIG. 13 is a simplified front view of a state where a small-diameter ring-shaped support body is assembled.

FIG. 14 is a simplified front view of a state where the diameter of the small-diameter ring-shaped support body is expanded.

[Explanation of symbols]

 1-1B Support pieces 1a, 1b Main girder 1c Joint plate 4a, 4b Push-up jack 5 Jack for expanding diameter 10 Tunnel excavator 11 Skin plate A Small ring-shaped support A 'Expanded ring-shaped support T Tunnel excavation wall

Continuation of the front page (56) References JP-A-10-252397 (JP, A) JP-B-46-28346 (JP, B1) JP-B-4-23960 (JP, B2)

Claims (6)

(57) [Claims] 1. A small-diameter ring-shaped support body comprising a plurality of rectangular frame-shaped support pieces curved in a tunnel circumferential direction in a skin plate of a tunnel excavator, and a rear side of the small-diameter ring-shaped support body is a tunnel excavator. A state in which the rear end side of the small-diameter ring-shaped support body is pushed up when the skin plate is relatively sent out from the rear end of the skin plate toward the tunnel excavation wall side, and its upper peripheral portion is in contact with the upper peripheral wall portion of the tunnel excavation wall surface. In this state, the diameter of the rear side of the small-diameter ring-shaped support body is increased to bring the rear outer peripheral surface into contact with the tunnel excavation wall surface. Then, the front side of the small-diameter ring-shaped support body is located behind the skin plate of the tunnel excavator. When the small-diameter ring-shaped support body is pushed out relatively from the end to the tunnel excavation wall side, the front end side of the small-diameter ring-shaped support body is pushed up to bring the upper peripheral portion into contact with the upper peripheral wall portion of the tunnel excavation wall surface. In this state, a method of forming a tunnel support body is characterized in that the diameter of the small-diameter ring-shaped support body is increased on the front side so that the outer peripheral surface of the small-diameter ring-shaped support body is entirely in contact with the tunnel excavation wall surface. 2. A small-diameter ring-shaped support body comprising a plurality of rectangular frame-shaped support pieces curved in the tunnel circumferential direction in a skin plate of a tunnel excavator, and a rear side of the small-diameter ring-shaped support body is a tunnel excavator. A state in which the rear end side of the small-diameter ring-shaped support body is pushed up when the skin plate is relatively sent out from the rear end of the skin plate toward the tunnel excavation wall side, and its upper peripheral portion is in contact with the upper peripheral wall portion of the tunnel excavation wall surface. Then, when the front side of the small-diameter ring-shaped support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall side, the front end side of the small-diameter ring-shaped support body is pushed up. The upper peripheral surface of the small-diameter ring-shaped support is brought into contact with the upper peripheral wall of the tunnel excavation wall over the entire length, and the small-diameter ring-shaped support is expanded while maintaining this state. A method for forming a tunnel support body, wherein the outer peripheral surface of the tunnel support body is entirely brought into contact with a tunnel excavation wall surface. 3. The small-diameter ring-shaped support body has a part of upper and lower support pieces joined so as to be circumferentially separable,
After being relatively sent out from the skin plate of the tunnel excavator to the tunnel excavation wall side, the small-diameter ring-shaped support body is expanded by separating from the above-mentioned joint portion in the circumferential direction, and the outer peripheral surface thereof is excavated. The method for forming a tunnel support according to claim 1, wherein the tunnel support is brought into contact with the support. 4. A cross section C of a downward opening by connecting a plurality of rectangular frame-shaped support pieces curved in the circumferential direction of the tunnel in the skin plate of the tunnel excavator from the upper peripheral portion of the skin plate along both sides. When the rear portion of the small-diameter support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall surface side, the rear end side of the small-diameter support body is pushed up to lift it up. When the peripheral portion is in contact with the upper peripheral wall portion of the tunnel excavation wall surface, and then, when the front side of the small diameter support body is relatively sent out from the rear end of the skin plate of the tunnel excavator to the tunnel excavation wall surface side, The small-diameter support body is pushed up at its front end to bring the upper peripheral surface of the small-diameter support body into contact with the upper peripheral wall of the tunnel excavation wall over the entire length. A small diameter ring-shaped support body is formed by incorporating the lower peripheral side support piece between the lower ends of both side support pieces of the body, and the diameter of the small diameter ring-shaped support body is expanded, and the outer peripheral surface is entirely covered with the tunnel excavation wall surface. A method for forming a tunnel support body, wherein the tunnel support body is brought into contact. 5. The small-diameter ring-shaped support body is lifted by a small-diameter ring-shaped support body or a small-diameter support body on a sliding frame that can reciprocate back and forth between a skin plate of a tunnel excavator and a tunnel excavation wall surface. The method for forming a tunnel support according to any one of claims 1 to 4, wherein the method comprises a push-up jack mounted with an interval between front and rear ends of the tunnel support. 6. The expansion means of the small-diameter ring-shaped support body,
The method of forming a tunnel support according to any one of claims 1 to 4, comprising an expansion jack.