JP2000054796A - Support unit for tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support unit for a tunnel which is erected at the lower peripheral part of a ground which is apt to collapse in bedrock of an excavated wall face of a tunnel and by which a propulsive reaction for excavation of the tunnel can be securely obtained. SOLUTION: This support unit A, A' for a tunnel is constituted of forward and rearward arcuate steel members 1, 3 having a length equal with the arcuate length of the lower peripheral part of an excavated wall face of the tunnel, and a plurality of propulsive reaction-supporting steel members 2 which are interposed between the central parts and both side end parts in the peripheral direction of the tunnel in these forward and rearward arcuate steel members 1, 3 and long in the longitudinal direction of the tunnel to connect the forward and rearward arcuate steel members 1, 3. These support units A, A' and support units A, A' supporting the upper peripheral part of the excavated wall face of the tunnel are combined to form a supporting body. When a propulsive reaction can not be obtained by a rear gripper of a tunneling excavator, a thrusting jack 7 equipped in the tunneling excavator is brought into contact with the forward arcuate steel member 1 corresponding to the front end face of the propulsive reaction-supporting steel members 2 to obtain the propulsive reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support unit for supporting an excavated wall of a tunnel.

[0002]

2. Description of the Related Art When a tunnel is excavated on a rocky ground by a tunnel excavator, the excavated tunnel wall surface may fall off or fall down. A ring-shaped support made of H-shaped steel is assembled along the tunnel wall, and a rock-fall prevention member such as expanded metal or wire mesh is stretched between the upper halves of the ring-shaped support adjacent to the front and rear to prevent this collapse. The member forms a support in the tunnel to prevent rocks loosened from the tunnel wall from collapsing.

On the other hand, tunnel excavation by a tunnel excavator is performed by pressing a pair of left and right rear grippers mounted on the tunnel excavator through the space between the front and rear ring-shaped supports against both side walls of the tunnel excavation wall. The propulsion reaction is applied to the wall and the propulsion jack is extended in this state.

[0004]

However, in the above-mentioned support work, when the tunnel excavation wall surface is soft rock ground, even if the rear gripper is pressed against the rock ground,
The pressure of the rear gripper compresses and breaks the rock ground, and cannot provide a sufficient propulsion reaction force to propel the tunnel excavator. For this reason, the tunnel excavator is provided with a pressing jack that expands and contracts in the axial direction, and the pressing jack is brought into contact with the lower half front surface of the ring-shaped support to support the propulsion reaction force on the ring-shaped support. In this state, if the pressing jack is extended together with the propulsion jack, the tunnel excavator can be excavated, but in this case, the ring-shaped support receiving the pressing jack is moved rearward by the extension of the pressing jack. A situation occurs in which bending deformation occurs and a sufficient propulsion reaction force cannot be obtained similarly to the rear gripper.

In recent years, a rectangular frame has been formed by connecting both ends of a pair of front and rear arc-shaped steel materials curved in the circumferential direction of the tunnel integrally with a straight steel material. Using a support unit in which a rock fall prevention member such as a wire mesh is stretched on the frame body, a ring-shaped tunnel support body in which a rock fall prevention member is stretched in an upper half portion is assembled. However, also in this tunnel support body, when the pressing jack is pressed against the intermediate portion of the arc-shaped steel material between the straight steel materials in the support unit, the arc-shaped steel material is bent backward and deformed in the same manner as described above. The propulsion reaction force of the excavator cannot be supported, and furthermore, the tunnel support body is damaged, or the entire tunnel support body is reduced in diameter by bending of the arc-shaped steel material, so that the support body with high accuracy is obtained. There is a problem that can not be construction.

The present invention has been made in view of such a problem, and an object of the present invention is to make it possible to use a tunnel excavator with a rear gripper which does not have sufficient propulsive reaction force of a tunnel excavator, even if the tunnel excavation wall is weak. An object of the present invention is to provide a tunnel support unit that can reliably and firmly receive a propulsion reaction force of an excavator.

[0007]

In order to achieve the above object, a tunnel support unit according to a first aspect of the present invention is configured such that when a tunnel excavator equipped with a pressing jack that expands and contracts in the length direction of the tunnel, the tunnel excavator excavates. A support unit in a support body for receiving a jack and taking a propulsion reaction force of a tunnel excavator, the arc-shaped steel material being curved in a circumferential direction of the tunnel, and protruding from the arc-shaped steel material in a tunnel length direction. It is composed of a steel material for supporting the reaction force of a certain length.

According to a second aspect of the present invention, there is provided a tunnel support unit comprising a pair of front and rear arc-shaped steel materials curved in a circumferential direction of the tunnel, and a fixed length having both ends fixed between opposing surfaces of the front and rear arc-shaped steel materials. And a steel material for supporting the propulsion reaction force.

According to the first or second aspect of the present invention, the tunnel support unit according to the third aspect is arranged such that the steel material for supporting the propulsion reaction force is disposed at the center and both ends in the longitudinal direction of the arc-shaped steel. It is characterized by having established.

[0010]

According to the present invention, a ring-shaped support body is formed by combining a plurality of support units curved in an arc shape in the circumferential direction of the tunnel according to the properties of the rock on the wall of the tunnel excavated by the tunnel excavator. In this case, when the tunnel excavation wall surface is a stable hard rock part, it is not necessary to install a fall prevention member on the support, but in the case of soft rock ground where the tunnel excavation wall surface easily collapses, An upper half portion of the support body is formed by a support unit in which a fall prevention member is stretched between a pair of arc-shaped steel materials arranged side by side at a certain interval, and a lower half portion of the support body, particularly, a tunnel. A support unit made of the arc-shaped steel material of the present invention and a steel material for supporting a propulsion reaction force is incorporated in the lower peripheral side of the excavated wall surface.

On the other hand, a plurality of pressing jacks, which extend and contract in the length direction of the tunnel, are mounted at regular intervals in the circumferential direction on the lower periphery of the skin plate in the tunnel excavator, so that the wall surface of the tunnel excavation becomes stable. In the case of hard rock ground, without using this pressing jack, the rear gripper is pressed between the front and rear arc-shaped steel materials of the support unit and on both sides of the excavation wall to take a reaction force on the excavation wall and extend the propulsion jack. Dig by letting it go.

When the tunnel excavation wall is soft rock ground which cannot take a sufficient propulsion reaction force due to the pressing of the rear gripper, the rear gripper is pressed against both sides of the tunnel excavation wall. The pressing jack is extended and pressed against the arc-shaped steel material of the support unit having the propulsion reaction force supporting steel material incorporated in the lower half of the support body. When the pressing jack is further extended in this state, the pressing force is reliably supported by the propulsion reaction force supporting steel material disposed in the length direction of the tunnel from the arc-shaped steel material, causing the arc-shaped steel material to bend. Without this support unit, the tunnel excavator can be excavated while taking a stable propulsion reaction force. If the arc-shaped steel member integrally provided with the steel material for supporting the propulsion reaction force is fixed to the excavated ground by means of anchor bolts, a stronger support unit for supporting the propulsion reaction force can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a support body S for supporting a soft tunnel excavation wall T having a loose collapsibility. A supporting unit A disposed along a lower peripheral portion of an arc-shaped steel material 1 made of a channel steel having a U-shaped cross section curved in a circumferential direction of a tunnel excavation wall surface T, and a rear surface of the arc-shaped steel material 1 And a propulsion reaction force supporting steel member 2 made of an I-shaped steel having a fixed length whose front end face is fixed by welding, and an arc-shaped steel member 3 having the same shape and the same length as the arc-shaped steel material 1.

In the support unit A, the arc-shaped steel material 1 made of a channel steel has the flange portions 1a, 1a directed backward, and the propulsion reaction force supporting steel material 2 is interposed between the flange portions 1a, 1a. The front end of the propulsion reaction force supporting steel material 2 is integrally fixed to the inner surface of the web 1b by inserting the front end thereof. Is attached in a state of projecting rearward from the arc-shaped steel material 1 in parallel with the steel material. In addition, three propulsion reaction force supporting steel members 2 having the same length are integrally fixed to three portions, that is, a center portion and both end portions in the length direction of the arc-shaped steel member 1.

On the other hand, the single arc-shaped steel material 3 has its flange portions 3a, 3a directed forward, that is, toward the arc-shaped steel material 1 having the propulsion reaction force supporting steel material 2, and the flange portions 3a, 3a.
The rear end surfaces of the propulsion reaction force supporting steel members 2, 2, and 2 are brought into contact with the front center portion and both end portions of the web 3b therebetween. Further, the arc length of these arc-shaped steel materials 1 and 3 is formed to be equal to the arc length of the lower peripheral portion of the tunnel excavation wall surface T.

FIG. 2 shows another support unit A 'according to the present invention.
The supporting unit is constituted by an arc-shaped steel material 1 integrally protruding the steel material 2 for supporting the propulsion reaction force and an arc-shaped steel material 3 separate from the arc-shaped steel material 1. In the unit A ′, the propulsion reaction force supporting steel members 2, 2, 2 are interposed between the arcuate steel materials 1, 3 at a certain interval in front and back of the unit 1 ′. Both ends are fixed by welding between the central portions of the web portions 1a and 3a in the longitudinal direction of the arc-shaped steel materials 1 and 3 facing each other and between the opposite ends, thereby forming a frame shape. Other structures and shapes are the same as those of the support unit A.

In the support units A and A ', the flanges 1a and 3a are disposed on the outer peripheral sides of the front and rear circular arc-shaped steel materials 1 and 3, that is, on the flanges 1a and 3a in contact with the tunnel excavation wall T in the longitudinal direction. A plurality of bolt mounting holes 4 are formed at small intervals (in the circumferential direction of the tunnel). The mounting position of the steel material 2 for supporting the propulsion reaction force on the arc-shaped steel material 1 is positioned on an extension of a portion where a plurality of pressing jacks 7 provided on a tunnel excavator 20 described below press against the front surface of the arc-shaped steel material 1. It is fixed to the part where it is located.

FIG. 3 shows a support unit B for supporting the upper peripheral portion of the tunnel excavation wall T in the support body S.
Along the tunnel excavation wall surface T, arc-shaped steel materials 11 and 12 made of a U-shaped channel steel with a constant length curved in an arc shape are arranged side by side at a certain interval in the front-rear direction (the length direction of the tunnel). At the same time, a straight steel material 13, 13 of a fixed length is fixed between both ends in the longitudinal direction of the front and rear arc-shaped steel materials 11, 12 to form a flat rectangular frame, which is curved into a convex arc shape of the rectangular frame. A sheet-like rock-fall prevention member 14 formed by combining bar-shaped metal wires in a lattice pattern is provided on the outer peripheral surface. In the case where the tunnel excavation wall surface T is a hard rock, a support unit consisting of only a rectangular frame without the collapse prevention member 14 may be used.

In the support unit B, bolt mounting holes 15 are formed at regular intervals in the opposed surfaces of the front and rear circular steel materials 11 and 12 and the opposed surfaces of the straight steel materials 13 and 13. In addition, also in the support unit A provided with the above-mentioned steel material 2 for supporting the propulsion reaction force, the front and rear arc-shaped steel materials 1 and 3 are provided with bolt mounting holes (not shown) at regular intervals in the length direction. It is preferable that a joint plate (not shown) provided with a bolt mounting hole for connecting the straight steel material 13 of the support unit B to both end surfaces of the front and rear arc-shaped steel materials 1 and 2 is fixed.

The support unit A or A 'thus constructed
The supporting body S supporting the tunnel excavation wall surface T is formed by sequentially connecting a desired number of the supporting units B in the circumferential direction of the tunnel. FIG. 4 shows an upper half portion and both side portions of a support body S for supporting an upper peripheral portion of a tunnel excavation wall T formed by a plurality of support units B on which the rockfall prevention member 14 is stretched. The lower part of the support body S that supports the lower peripheral part of the excavation wall T is formed by the support unit A or A ′ having the steel material 2 for supporting the propulsion reaction force.

More specifically, a support unit B on which the rock-fall prevention member 14 is stretched is disposed at the center of the upper peripheral portion of the tunnel excavation wall T. The supporting unit B is supported by the peripheral wall portion.
The support units having the same structure as the support unit B or the support units B 'and B' in which the rock fall prevention member 14 is stretched in the upper half portion are disposed on both sides in the circumferential direction of the tunnel. B ', the straight steel material 13 on the upper side of B'
Of the tunnel excavation wall T by means of these support units B ', B'. Let me.

Further, the support unit A or A 'having the steel material 2 for supporting the propulsion reaction force is laid on the lower peripheral portion of the tunnel excavation wall surface T, and tunnel excavation is performed at both end surfaces of the arcuate steel materials 1, 3 before and after the support unit A or A'. The support units B ′ supporting both sides of the wall surface T, the front and rear ends of the lower straight steel material 13 on the lower side B ′ are received,
Both ends of the straight steel material 13 and the front and rear arc-shaped steel materials 1 and 3 of the support unit A or A 'are integrally connected via a joint plate or the like, and are connected to the tunnel excavation wall T of the support unit A or A'. A lock bolt 5 is driven into the rock ground from the lower peripheral portion of the tunnel excavation wall T through a plurality of bolt mounting holes 4 drilled in the flange portions 1a and 3a on the contact side, and the support unit A is fixed by the lock bolt 5. It is firmly fixed to the tunnel excavation wall T.

In the case of the support unit A ', the front end face of the rear arc-shaped steel material 3 is provided on the rear end face of the propulsion reaction force supporting steel material 2 projecting rearward from the front arc-shaped steel material 1. Assembled by butting and joining. in this case,
Since the front and rear arc-shaped steel materials 1 and 3 are formed separately,
Handling during loading into the tunnel or assembling the support body is facilitated.

Such a support body S is provided with a tunnel excavator 20.
Along with the excavation, is constructed sequentially on the exposed excavation wall T,
A series of tunnel supports that support the tunnel excavation wall surface T by connecting the front and rear adjacent support members S, S joined to each other by connecting the front and rear arc-shaped steel materials to each other by inserting bolts into bolt mounting holes and screwing nuts. Is formed.

As shown in FIG. 5, the tunnel excavator 20 has a support member 22 provided integrally with the skin plate 21 at the front end opening of the cylindrical skin plate 21, and
A cutter plate 23 rotatably supported by the support member 22 and rotationally driven by a drive motor (not shown) mounted in the support member 22; and a front end integrally fixed to a rear end of the support member 22 A beam 24 extending horizontally rearward from the rear end of the skin plate 21 through the center space of the skin plate 21; and a telescopic front mounted integrally on the upper, lower, left and right sides of the support member 22. A gripper 25, a rear support 26 projecting downward from the lower surface of the rear end of the beam member 24 and being vertically expandable and contractable by a jack 26a, and a beam receiver 29 slidably disposed along the lower surface of the beam member 24. , And a propulsion jack 28 connecting the support member 22 and the rear gripper 27.

Further, in the tunnel excavator 20 constructed as described above, a plurality of support units A and B are connected in the skin plate 21 in the circumferential direction to assemble the annular support body S. An assembling elevator 6 is provided, and a plurality of pressing jacks 7 that extend and contract in the length direction of the tunnel at regular intervals in the circumferential direction are mounted on the lower peripheral portion of the skin plate 21. The pressing jack 7 is provided at a position corresponding to the steel material 2 for supporting the propulsion reaction force of the support unit A or A ', that is, at the same number as the steel material 2 for supporting the propulsion reaction force, and Are provided at the same intervals.

The above-mentioned ring-shaped support body in which the support units adjacent to each other in the circumferential direction of the tunnel are connected in the rear end portion of the skin plate 21 of the tunnel excavator 20 using the erector 6 in a temporarily tightened state. Assemble S. The support unit A or A 'constituting the lower peripheral portion of the support body S sends out the upper half of the support body S from the skin plate 21 to the tunnel excavation wall T side, and then, on the bottom surface of the tunnel excavation wall T. May be performed.

The support body S (hereinafter referred to as a new support body) assembled in the skin plate 21 of the tunnel excavator 20 in this manner is a front end face of the existing support body S whose rear end face is sent out to the tunnel excavation wall T side. And then sent out to the tunnel excavation wall T side in accordance with the excavation of the tunnel excavator 20, and then the diameter thereof is increased so that the outer peripheral surface thereof is in close contact with the tunnel excavation wall T. In this state, the new support body S and the existing support body S
Is connected with bolts and nuts and the new support body S
The support units constituting the above are also connected by bolts and nuts.

As described above, the step of connecting the support body S assembled in the skin plate 21 to the assembled support body S, and sending out the new support body S from the rear end of the skin plate 21 according to the excavation of the tunnel excavator 20. By repeatedly performing the step of supporting the tunnel excavation wall surface T by performing the step, a series of supports that support the tunnel excavation wall surface T over the entire length are formed.

The tunnel excavator 1 excavates the tunnel by using the rear grippers 27, 27 of the tunnel excavation wall surface T between the front and rear circular arc-shaped steel materials 11, 12 at the connecting portion between the upper half and the lower half of the support body S. After the propulsion reaction force is obtained by pressing against both side surfaces, the rear support 26 is contracted and separated from the bottom surface of the tunnel excavation wall T, and then the propulsion jack 28 is extended to extend the tunnel excavation wall via the rear gripper 27. The front gripper 25 is excavated by the cutter plate 23 while sliding the front gripper 25 against the excavation wall surface T with the reaction force supported by T. After excavating a tunnel of a certain length, the front gripper 25 is firmly pressed against the excavation wall T, and the rear support 26 is extended to be supported on the bottom surface of the excavation wall T, and the rear gripper 27 is contracted. The rear gripper 27 is advanced to the next crimping position along the beam member 24 by contracting 28.

At this time, if the tunnel excavation wall T is made of a soft rocky material which is liable to collapse or fall off, sufficient propulsion can be achieved even if the rear grippers 27 are pressed against both side wall portions of the tunnel excavation wall T. No reaction force can be taken. Therefore, in such a case, the rear grippers 27, 27 are pressed against both side wall portions of the tunnel excavation wall surface to take a certain propulsion reaction force, while the skin plate 21 of the tunnel excavator 20 is pressed.
The pressing jack 7 attached to the lower peripheral portion of the inner portion is extended to contact the front surface of the front circular arc-shaped steel material 1 of the support unit A or A 'constituting the lower peripheral portion of the support body S. The support unit supports the propulsion reaction force of the tunnel excavator 20.

At this time, as shown in FIG. 6, the lower peripheral portion of the front and rear support bodies S, S is formed by a propulsion reaction force supporting steel material 2 parallel to the front and rear arc-shaped steel materials 1 and 3 in the tunnel length direction. These propulsion reaction force supporting steel members 2 are formed by supporting units A or A 'which are integrally connected, and these propulsion reaction force supporting steel members 2 are disposed in a state of being continuously connected in a straight line in the tunnel length direction. Since the pressing jack 7 is brought into contact with the front surface of the front circular arc-shaped steel material 1 of the support unit A or A 'in the foremost support body S corresponding to the front end face of the steel material 2, the pressing jack 7 is extended. The pressing force is firmly received by the propulsion reaction force supporting steel material 2 through the arc-shaped steel materials 1 and 3, and the support unit A or A 'is not bent by the arc-shaped steel materials 1 and 3 at all. Tunnel taking the propulsion reaction of tunnel excavator 20 Those capable of boring the excavator 20. Further, since the front and rear arc-shaped steel materials 1 and 3 of the support unit A or A 'are fixed to the excavated ground by the lock bolts 5, the support unit for supporting the propulsion reaction force can be further strengthened. In addition, the support unit of the present invention,
Depending on the arrangement of the pressing jack of the tunnel excavator, it may be used not only for the lower peripheral part but also for the upper peripheral part and the side peripheral part.

[0033]

As described above, according to the support unit of the present invention, during excavation of a tunnel excavator equipped with a pressing jack that expands and contracts in the lengthwise direction of the tunnel, the pushing jack is received and the propulsion of the tunnel excavating machine is performed. This is a support unit in a support body for taking a reaction force, and a propulsion reaction force supporting steel material of a fixed length is interposed between facing surfaces of front and rear arc-shaped steel materials curved in the circumferential direction of the tunnel, so that a tunnel excavation wall surface is formed. However, in the case of soft rock ground that cannot take a sufficient propulsion reaction force despite the pressing of the rear gripper of the tunnel excavator, the pressing jack is extended and incorporated into the lower half of the support body. By pressing against the arc-shaped steel material of the support unit having the propulsion reaction force supporting steel material, the propulsion reaction force of the tunnel excavator can be reliably supported, and the propulsion reaction force support By arranging the material on the extension of the pressing jack, it is possible to smoothly excavate soft rock while firmly supporting the propulsion reaction force on the propulsion reaction force supporting steel material without bending and deforming the arc-shaped steel material. Things.

Further, the support unit is provided with a pair of front and rear arc-shaped steel members and several propulsion reaction force supporting steel members disposed between opposing surfaces of the arc-shaped steel members without extending a rock fall prevention member or the like. Not only is the structure simple and easy to manufacture, but also the steel material for supporting the propulsion reaction force is fixed to one of the arc-shaped steel materials or interposed between the two arc-shaped steel materials and both ends are When fixed to the opposite surface of the arc-shaped steel material, it can be arranged at the position corresponding to the multiple pressing jacks arranged on the tunnel excavator, ideal for supporting the propulsion reaction force of the tunnel excavator It is possible to constitute a simple support unit.

[Brief description of the drawings]

FIG. 1 is a perspective view of a support unit according to the present invention;

FIG. 2 is a perspective view of a support unit having another structure of the present invention,

FIG. 3 is a perspective view of a support unit on which a rock fall prevention member is stretched;

FIG. 4 is a longitudinal front view of the support body,

FIG. 5 is a simplified longitudinal side view of a tunnel excavator on which a support body is being constructed;

FIG. 6 is a plan view of a cross section of a part of the support unit that receives the pressing jack.

[Explanation of symbols]

 1, 3 front and rear arc-shaped steel material 2 steel material for supporting propulsion reaction force 4 bolt mounting hole 5 lock bolt 7 pressing jack 20 tunnel excavator A, A 'support unit S support body

Continued on the front page (72) Inventor Junji Ono 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka-shi F-term in Okumura Gumi Co., Ltd. (Reference) 2D055 BB01 FB00

Claims (3)

[Claims] 1. A support unit in a support body for receiving a pressing jack and taking a propulsive reaction force of the tunnel excavator when a tunnel excavator having a pressing jack that expands and contracts in a tunnel length direction is excavated. A tunnel support unit comprising: an arc-shaped steel material curved in a tunnel circumferential direction; and a propulsion reaction force supporting steel material of a fixed length protruding from the arc-shaped steel material in a tunnel length direction. 2. A support unit in a support body for receiving a pressing jack and taking a propulsive reaction force of the tunnel excavator when a tunnel excavator having a pressing jack that expands and contracts in a tunnel length direction is excavated. A pair of front and rear arc-shaped steel materials curved in the circumferential direction of the tunnel, and a propulsion reaction force supporting steel material of a fixed length having both ends fixed between opposing surfaces of the front and rear arc-shaped steel materials. Support unit. 3. The tunnel support unit according to claim 1, wherein the propulsion reaction force supporting steel material is disposed at a central portion and both end portions in a longitudinal direction of the arc-shaped steel material. .