JP3234184B2 - Support piece - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support piece for supporting an excavated wall surface excavated by a tunnel excavator. When it is, it is related to the support piece to be constructed on the rock part.

[0002]

2. Description of the Related Art When a tunnel excavator excavates a tunnel in rocky ground, the rear gripper of the tunnel excavator is pressed against both side wall portions of the tunnel excavation wall to receive a reaction force of the excavation and extend the propulsion jack. This is how the tunnel excavator excavates. At this time, the excavated tunnel wall surface may fall off or fall down.
As shown in FIG. 2, a plurality of support pieces 31 which are curved in an arc shape and have a rock-fall prevention wire mesh body 32 stretched on the outer peripheral surface are sequentially connected to assemble a ring-shaped support body A ′, and the support is assembled. The body A 'prevents the rock mass loose from the tunnel excavation wall T from collapsing.

[0003]

However, in the conventional support piece 31, the four-sided peripheral portion of the rock-fall prevention wire netting 32 is integrally fixed to the outer peripheral end surface of the rectangular frame of the support piece 31 by welding. For this reason, when the tunnel excavator is propelled, even if the rear gripper is crimped to both side wall portions of the tunnel excavation wall via the rock fall prevention wire netting 32, the rock mass B to which the rear gripper is crimped has a loose collapsible rock. In the case of a hard ground, the compression force of the wire mesh body 32 for preventing rock fall against the rock part becomes weak, and a sufficient propulsion reaction force for propelling the tunnel excavator cannot be obtained.

[0004] For this reason, by increasing the pressing force of the rear gripper to swell and deform the wire mesh body 32 for preventing rock fall from the rock part B side, the collapsed rock part B in which the rock is loose is compacted. It is sufficient to increase the locking force of the rear gripper, but the four sides of the rock mesh fall prevention wire mesh 32
Since the wire mesh 32 for rock fall is swelled and deformed by the pressing force of the rear gripper because it is fixed on the rectangular frame 31 by welding, a large tensile force is generated in the wire mesh 32 for rock fall. There is a problem in that the front and rear main girders of the rectangular frame to which the wire mesh body 32 is fixed are bent and deformed in a direction approaching each other, and cannot function as a support for the tunnel excavation wall surface.

The present invention has been made in view of such problems, and an object of the present invention is to provide a tunnel excavator having a collapsible loose ground on a wall surface of a tunnel excavation for obtaining a propulsion reaction force. It is an object of the present invention to provide a support piece that can be applied to a rock mass to reliably take a propulsion reaction force of a tunnel excavator.

[0006]

In order to achieve the above object, a support piece according to a first aspect of the present invention is a rectangular frame formed by fixing a joint plate between both ends of a front and rear main girder curved in an arc shape. In the support piece having a rock-fall preventing wire mesh attached to the outer peripheral surface side of the main body of the support piece, the rock-fall prevention
The four peripheral edges of the metal mesh for stopping are outside the rectangular frame mainly supporting the piece.
This rock is mounted without being fixed to the peripheral end face.
Laminate the strip on the four edges of the wire mesh to prevent board collapse
To secure the strip to the outer peripheral end surface of the support frame.
Then, the band plate and the outer peripheral end face of the rectangular frame
The four-way peripheral edge portion of the rock collapse prevention net member has a structure in which the rock collapse prevention net member is bulged deformable is interposed outward from the outer circumferential surface of支保piece mainly between.

[0007] On the other hand, the invention according to claim 2 is an arc-shaped bay.
Rectangular frame with joint plates fixed between both ends of curved main girder
Wire mesh for rock fall prevention
In支保piece composed by attaching a, for 該岩Release collapse prevented without sticking to支保piece mainly edges of at least one side of the square peripheral edge of the rock collapse preventing net member
The wire mesh expands outward from the outer peripheral surface of the support piece.
State than deformable支保piece mainly out began to stretch outward
It is a structure that is mounted on.

[0008] The invention according to claim 3 is that the bay is formed in an arc shape.
Rectangular frame with joint plates fixed between both ends of curved main girder
Wire mesh for rock fall prevention
In the support piece to which is attached , at least two opposing edges of the four-sided edge of the rock fall prevention wire mesh body are formed with a slack portion of an appropriate length inward and
The distal end portion of the Kataen portion Yes by fixing the支保piece mainly the
A rock mesh fall prevention wire mesh body is supported by a loose part.
The structure is such that it can be swelled and deformed outward from the outer peripheral surface of the .

Further, the invention according to claim 4 is characterized in that the circular arc shape is used.
A rectangle with a joint plate fixed between both ends of the curved main girder
A wire mesh for rock fall prevention on the outer peripheral side of the frame-shaped support piece
In the support piece to which the body is attached, the rock-fall preventing wire mesh is dished into a space surrounded by a rectangular frame mainly composed of the support piece, and the rock-fall preventing wire mesh is provided outside the rock-fall preventing wire mesh. The structure has a structure in which the ends of the four-sided peripheral portions rising toward the front are fixed to a rectangular frame mainly composed of support pieces.

[0010]

The ring-shaped support body is assembled by sequentially connecting a plurality of rectangular frame-shaped support pieces curved in an arc shape in the circumferential direction of the tunnel, and the outer peripheral surface thereof is applied to the wall surface excavated by the tunnel excavator. Contact and support the excavation wall. At this time, a wire mesh for preventing rock fall may be stretched on all the support pieces, but since the loose rock fall or skin drop occurs on the upper peripheral side of the tunnel, Only the support pieces arranged on the peripheral side may be provided with a wire mesh for rock fall prevention. This support is constructed every time the tunnel excavator excavates.

In the excavation of the tunnel excavator, the rear gripper is pressed against the both side wall portions of the tunnel excavation wall through the frame of the both side support pieces in the existing support body supporting the tunnel excavation wall surface, and the reaction force is supported on the both side wall surfaces. This is performed by extending the propulsion jack while rotating the cutter head in the state where the cutter head is rotated. At this time, if the rock on both sides of the tunnel excavation wall to which the rear gripper of the tunnel excavator is crimped is loose, a wire mesh for rock fall prevention is placed in advance at that point outward from the outer peripheral surface of the support piece main body. A support body provided with a support piece attached so as to be swellable and deformable is constructed in advance. The rear gripper is pressed against both side walls via the rock fall prevention wire mesh.

When the rear gripper is extended to press the wire mesh for preventing rock fall, the wire mesh expands and deforms outward by the pressing force of the rear gripper without deforming the rectangular frame mainly composed of the support pieces, and the loose rock The part can be firmly pressed against this bedrock while consolidating, so that the tunnel excavator can take the stable and reliable reaction force required for propulsion.

At this time, as described in the first aspect, the four-sided peripheral portion of the wire mesh body for rock fall prevention is placed without being fixed to the outer peripheral end surface of the rectangular frame mainly composed of the support piece, and the rock fall prevention is performed. A band plate is superimposed on the four-sided peripheral portion of the wire mesh body, and the band plate is fixed to the outer peripheral end surface of the rectangular frame mainly composed of the support piece. In the case of the structure in which the four-sided peripheral edge of the fall prevention wire mesh is slidably sandwiched, when the center portion of the rock fall prevention wire mesh is pressed by the rear gripper, the four-sided periphery of the wire mesh is supported. It moves so as to be drawn toward the center of the rectangular frame from between the outer peripheral end face of the main rectangular frame and the strip, and swells toward the rock without deforming the rectangular frame. Consolidate.

Further , as described in claim 2, at least one edge of the four-sided peripheral edge of the wire mesh for rock fall prevention is placed without being fixed to the support piece main body, and the rectangular frame-shaped metal mesh body is placed. If it is configured to protrude outward from the support piece main body, the pressing force of the rear gripper causes the wire mesh body to move its fixed edge to the fulcrum and the other edge toward the pressing portion side of the rear gripper and bulge and deform. The rock part is compacted without deforming the rectangular frame mainly composed of support pieces.

Further, as described in claim 3 , a slack portion of an appropriate length is formed inward at least at two opposing edges of the four edges of the wire mesh body for preventing rock fall. When receiving the pressing force of the rear gripper, the wire mesh body moves toward the pressing portion side of the rear gripper while gradually loosing its slack portion, and swells and deforms. The rock mass can be compacted and the propulsion reaction force can be obtained without deforming the rock.

Still further, as described in claim 4 ,
An end portion of a four-sided peripheral portion of the wire mesh for rock fall prevention, which is recessed in a dish shape into a space surrounded by a rectangular frame mainly composed of a support piece and rises outward from the wire mesh for rock fall prevention. Is fixed to a rectangular frame mainly composed of support pieces, the dish-like wire mesh body is turned outward by the pressing of the rear gripper with the four peripheral edges as fulcrums, The rock mass can be compacted and a propulsion reaction force can be obtained without bulging out and deforming the rectangular frame mainly composed of the support pieces.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of the present invention will be described with reference to the drawings. FIGS. 1 to 4 show side walls of a tunnel excavation wall T to which a rear gripper 17 of a tunnel excavator 10 to be described later is pressed. When the portion is a loose rock part B which is collapsible, it is a support piece incorporated in a ring-shaped support body A for supporting the rock part B, and the support piece main body 1 is another support piece constituting the support body A. Similarly, from the steel rectangular frame which is integrally fixed by flat plate-shaped joint plates 1c, 1d between both ends in the longitudinal direction of the front and rear main girders 1a, 1b curved in an arc along the tunnel excavation wall surface T. In this case, bolt mounting holes 6 and 7 are formed in the front and rear main girders 1a and 1b and the joint plates 1c and 1d at regular intervals in the length direction. Further, a flat rectangular rock-fall preventing wire netting body 2 formed by combining bar-shaped metal wires in a lattice shape on the outer peripheral surface of the support piece main body 1 is disposed outwardly from the outer peripheral surface of the support piece main body 1 curved in a convex arc shape. The four-sided peripheral portion is attached to the outer peripheral end surface of the rectangular frame of the support piece main body 1 so as to be swellable and deformable toward the rock mass B).

As the mounting structure, in the support piece A1 shown in FIG. 1, a wire mesh 2 for preventing the rock from falling into a flat rectangular shape having a width and a length one size larger than the flat shape of the support piece main body 1 is used. The four-sided peripheral portion is placed on the outer peripheral end surface of the rectangular frame of the support piece main body 1 in a state where it protrudes 2a outward from the rectangular frame of the support piece main body 1, and covers the opened outer peripheral surface of the support piece main body 1. The strip 3 made of steel plate is superimposed on the rectangular frame of the support piece main body 1, that is, on the four-sided peripheral portion of the wire mesh body 2 on the outer peripheral end surfaces of the front and rear main girders 1 a and 1 b and the joint plates 1 c and 1 d. The band plate 3 and the support piece main body 1 are fixed to the rectangular frame of the support piece main body 1 by welding the metal wires of the wire mesh body 2 for rock fall prevention to several places at both ends and an intermediate portion in the vertical direction. Around the four sides of the wire mesh 2 for rock fall prevention It is made to clamp the part.

Therefore, when the rear gripper 17 of the tunnel excavator 10 presses from the inner peripheral side of the support piece A1 to the center of the wire mesh body 2 for preventing rock fall, it protrudes outward from the rectangular frame of the support piece main body 1. The protruding portion 2a of the rock fall prevention wire mesh 2 is drawn toward the center of the support piece body 1 between the rectangular frame of the support piece body 1 and the strip 3 so that the rock fall prevention wire mesh 2 moves outward. It swells and deforms.

The support piece A2 shown in FIG. 2 has a structure in which the rock mesh prevention metal net 2 is attached to the support piece main body 1.
The width dimension is the width dimension of the support piece main body 1, that is, the joint plate 1c,
A vertically elongated rock-fall prevention wire netting 2 having a length equal to the length of 1d and a length longer than the main girders 1a and 1b of the support piece main body 1 is attached to one short side of one edge. It is fixed to the outer peripheral end surface of one joint plate 1c of the support piece main body 1 by welding, and is mounted on the main girders 1a, 1b and the joint plate 1d without fixing the other three side edges, and is fixed from the joint plate 1d. It is stretched in a state where the length portion protrudes 2b in the extension direction.

Therefore, when the rear gripper 17 of the tunnel excavator 10 presses from the inner peripheral side of the support piece A2 toward the center of the wire mesh 2 for preventing rock fall, the joint plate of the support piece main body 1 is pressed.
The rock fall prevention wire mesh 2 bulges outward while the projection 2b of the rock fall prevention wire mesh 2 projecting outward from 1d is drawn toward the center of the support piece main body 1. . In addition, the length of the wire mesh 2 for rock fall prevention is formed to be equal to the length of the support piece main body 1 and the lateral width is made wider than that of the support piece main body 1, and one edge of the longer side is formed. The support piece main body 1 may be fixed on one main girder, and the other three sides may be mounted without being fixed. In other words, the four-sided peripheral portion of the rock-fall prevention wire netting 2 may be used. Of the rectangular frame-shaped support piece main body 1 is fixed to at least one side of the support piece main body 1 without being fixed thereto.
It is better to project more outward.

The support piece A3 shown in FIG. 3 has a structure in which a wire mesh 2 for rock fall prevention is attached to the support piece main body 1.
The four-sided peripheral portion of the rock fall prevention wire netting 2 is formed inward, that is, a slack portion 2c curved in a U-shape from the outer peripheral side to the inner peripheral side of the support piece main body 1, and the slack portion 2c is formed. Are provided along the inner peripheral surface of the rectangular frame of the support piece main body 1, and the leading end of the slack portion 2c is fixed to the inner peripheral back surface of the rectangular frame by welding. Therefore, this support piece A3
When the rear gripper 17 of the tunnel excavator 10 presses against the center of the rock fall prevention wire mesh 2 from the inner peripheral side of the rock excavation, the slack portion 2c expands and the rock fall prevention wire mesh 2 bulges outward and deforms. It is.

The support piece A4 shown in FIG. 4 has a structure for mounting the rock mesh prevention metal mesh 2 to the support piece main body 1.
The four-sided peripheral portion is curved outward (from the inner peripheral surface side to the outer peripheral surface side of the support piece main body 1), so that the planar shape is the same as that of the support piece main body 1, and a dish-shaped rock-fall prevention wire netting body 2. The tip of the raised four-sided peripheral edge portion 2d of the rock fall prevention wire netting 2 is fixed to the inner peripheral back surface of the rectangular frame of the support piece main body 1 by welding. Therefore, the tunnel excavator 10 is positioned from the inner peripheral side of the support piece A3.
When the rear gripper 17 presses against the center of the wire mesh 2 for preventing rock fall, the dish-shaped wire mesh 2 is inverted outward in the rectangular frame with the tip of the four-sided peripheral portion 2c as a fulcrum, and It swells and deforms toward.

FIG. 5 shows a tunnel excavator 10, in which a support member 12 is disposed integrally with the skin plate 11 at the front end opening of a cylindrical skin plate 11, and the support member 12 is rotated. A cutter plate 13 that is freely supported and is rotationally driven by a drive motor (not shown) mounted in the support member 12, and a front end thereof is integrally fixed to a rear end of the support member 12, A beam body 14 extending horizontally rearward from the rear end of the skin plate 11 through a central space of the skin plate 11, and a radially expandable and contractible front mounted integrally on the upper, lower, left and right sides of the support member 12. A gripper 15, a rear support 16 protruding downward from the lower surface of the rear end of the beam member 14 and capable of vertically extending and contracting by a jack 16a; and a rear gripper 17 slidably disposed along the lower surface of the beam member 14. , Support member 12 and rear bar And a propulsion jack 18 connecting between the upper and lower beams 17, and a cylindrical sliding frame
A sliding jack 19 is slidably fitted, and a lifting jack 20 is fixed on the upper surface of the sliding frame 19.

The skin plate 11 has a beam member 14.
The rear gripper 17 is integrally fixed to and supported on the outer peripheral surface of the beam body 14 via a connecting frame member 21 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 22 slidable relative to the body 14 projects horizontally from both lower surfaces of the beam receiver 22 toward both side surfaces of the tunnel excavation wall surface 2 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 sliding frame 19 and the beam receiver 22 are connected via a connecting jack 23. The cutter head 13
The excavated earth and sand is discharged backward by an appropriate carrying-out means such as a conveyor (not shown).

In the rear end of the skin plate 11 of the tunnel excavator 10 thus configured, the tunnel excavation wall T
A ring-shaped support body A is assembled by connecting a plurality of support pieces having a predetermined arc length curved in an arc shape along the circumference in the circumferential direction using an erector (not shown). At this time, as is well known, the support piece A that supports at least the upper peripheral portion of the tunnel excavation wall surface T uses a support piece formed by extending and fixing the rock fall prevention metal mesh body 2 to the support piece main body 1 as is well known. .

Then, the ring-shaped support body A is connected by bolts and nuts 8 (shown in FIG. 7) between the bolt mounting holes 7 which communicate with each other by opposing the joint plates 1c and 1d of the support piece. Thus, the support pieces are assembled in a ring shape while connecting the support pieces in the circumferential direction. Although the support body A is formed from four support pieces in the drawing, the support body may be formed by combining four or more support pieces.

The support body A thus assembled is sent out from the skin plate 11 to the tunnel excavation wall T side along with the excavation of the tunnel excavator 10, and the tunnel excavation wall T is supported. That is, the support body A assembled in the skin plate 11 is supported by the push-up jack 20 on the slide frame 19, and the slide frame 19 is moved rearward along the beam body 14 to tunnel the support body A. The support body A is sent out to the side of the excavation wall T, the diameter of the support body A is expanded, and the outer peripheral surface thereof is brought into close contact with the tunnel excavation wall T to support the tunnel excavation wall T, and the rear main girder 1b of the support body A has already been constructed. The bolt insertion holes 4, 4 communicating with each other on the front main girder 1 a of the support body A are connected and integrated by bolts and nuts.

The support A is sent from the inside of the skin plate 11 to the tunnel excavation wall T from the tunnel T side without using the sliding frame 19 on which the push-up jack 20 is mounted as described above. The diameter of the support body A may be expanded by appropriate means such as appropriate tension. The support piece body 1 on the lower peripheral side is connected between the opposing joint plates 1c and 1d of the support piece body 1 with a jack or the like. This is done by separating them.

On the other hand, when assembling the support body A in the skin plate 11 as described above, the rock properties of the tunnel excavation wall T excavated by the tunnel excavator 10 are observed, and the side wall surface portion of the tunnel excavation wall T is observed. In the case where a loose rock mass is present in the ground,
As shown in the figure, any one of the support pieces A1 to A4 on which the wire mesh 2 for rock fall prevention is stretched
The support body A is sent out to the tunnel excavation wall surface portion having the collapsed loose rock portion B exposed rearward from the skin plate 11 as the tunnel excavator 10 excavates and the wire mesh 2 for rock fall prevention. The rock part B is supported by the support pieces that are stretched.

In the excavation by the tunnel excavator 1, the rear grippers 17, 17 are pressed into the side walls of the tunnel excavation wall 2 through the frames of the support pieces on both sides of the support A to obtain a propulsion reaction force. Shrink the support 16 to separate it from the bottom of the tunnel excavation wall T, and then
By extending the propulsion jack 18, the rear gripper 17
The cutter head 13 excavates the front gripper 15 while sliding the front gripper 15 against the excavation wall surface 2 while supporting the reaction force on the tunnel excavation wall surface T. After excavating the tunnel of a certain length, the front gripper 15 is brought into a state of being strongly pressed against the excavation wall T, and the rear support 16 is extended to be supported on the bottom surface of the excavation wall T, and the rear gripper 17 is contracted. The propulsion jack 18 is contracted and the beam 14
, The rear gripper 17 is advanced to the next crimping position.

When the tunnel excavator 10 excavates, if the side wall of the tunnel excavation wall T to which the rear grippers 17 and 17 are crimped is a loose rock portion B in which cracks and collapses have occurred,
Since the rock part B is supported by the supporting piece which stretches the wire mesh body 2 for preventing rock collapse which can be expanded and deformed as described above, the rear grippers 17, 17 are extended to press the metal mesh body 2. Then, the wire mesh body 2 swells and deforms outward by the pressing force of the rear gripper 17 without deforming the support piece main body 1 as shown in FIG. A stable and reliable reaction force necessary for propulsion can be obtained.

The swelling deformation of the rock fall prevention wire netting 2 is caused by the protrusion 2a projecting outward from the rectangular frame of the support piece main body 1 in the case of the rock fall prevention wire netting 2 shown in FIG. By pressing the rear gripper 17, the space between the rectangular frame of the support piece main body 1 and the band plate 3 is drawn toward the center of the support piece main body 1, and the rock fall prevention wire netting 2 swells and deforms outward. . Further, in the case of the rock-fall preventing wire mesh 2 shown in FIG. 2, the projection 2b of the rock-fall preventing wire mesh 2 projecting outward from the joint plate 1d of the support piece main body 1 by the pressing of the rear gripper 17 is formed. The support piece main body 1 is drawn toward the center thereof, and the rock fall prevention wire netting 2 swells and deforms outward.

Further, the wire mesh 2 for rock fall prevention shown in FIG.
In the case of FIG. 7, when the rear gripper 17 of the tunnel excavator 10 presses against the center of the rock-fall preventing wire netting 2 as shown in FIGS. The body 2 swells and deforms outward. In the case of the wire mesh 2 for preventing rock fall as shown in FIG. 4, the dish-like wire mesh 2 has four peripheral edges as shown in FIG. The inside of the rectangular frame is inverted outwardly with the tip of the portion 2c as a fulcrum, and swells and deforms toward the rock portion B. In any case, the rock portion B is compacted and the thrust force is reliably applied to the rear gripper 17. Can be taken.

[0035]

As described above, according to the support piece of the present invention, the bedrock is provided on the outer peripheral surface side of a rectangular frame-shaped support piece mainly formed by fixing a joint plate between both ends of the front and rear main beams curved in an arc shape. In a support piece with a fall prevention wire mesh attached,
Since the rock fall prevention wire mesh body is attached to the support piece-based rectangular frame so as to be swellable and deformable outward from the outer peripheral surface of the support piece-based body, the rear gripper of the tunnel excavation wall surface is extended to extend the rear gripper. When the wire mesh for rock fall prevention is pressed, the wire mesh swells and deforms outward by the pressing force of the rear gripper without deforming the rectangular frame mainly composed of the support pieces. It can be firmly press-bonded, and therefore, can take a stable and reliable reaction force required for propulsion of the tunnel excavator.

As a mounting structure of the rock fall prevention wire mesh body to the support piece main body, the invention according to claim 1 fixes the four-sided peripheral portion of the rock fall prevention wire netting to the outer peripheral end surface of the rectangular frame mainly comprising the support piece. And a band plate is superimposed on the four-sided peripheral portion of the wire mesh body for preventing rock fall, and the band plate is fixed to the outer peripheral end surface of the rectangular frame mainly composed of the support piece. Since the four-sided peripheral edge of the rock fall prevention wire mesh body is sandwiched between the outer peripheral end surface of the main body rectangular frame and the rock fall prevention wire mesh body, when the rear gripper presses the rock fall prevention wire mesh body, the rectangular frame mainly comprising the support piece. The protrusion protruding outward from the support piece is drawn toward the center of the support piece main body between the rectangular frame and the band plate of the support piece main body, and the rectangular frame shape is held without deforming the support piece main body at all. Was The rock collapse prevention net member can be bulged deformed outwardly in state.

In the invention according to a second aspect, at least one edge of the four-sided peripheral edge of the rock-fall prevention wire mesh body is placed without being fixed to the support piece main body, and is not fixed. Since the edge is formed so as to protrude outward from the main body of the rectangular frame-shaped support piece, the pressing force of the rear gripper causes the wire mesh body to fix the one edge fixed to the fulcrum and the three edges to the pressing portion of the rear gripper. It moves to the side and swells and deforms, so that the rock part can be compacted without deforming the rectangular frame mainly composed of the support piece, and a reliable propulsion reaction force by the rear gripper can be obtained.

Further, the invention according to claim 3 has a structure in which a slack portion of an appropriate length is formed inward at least at two opposing edges of the four edges of the wire mesh for preventing rock fall. Therefore, when receiving the pressing force of the rear gripper,
The wire mesh moves toward the pressing part of the rear gripper while gradually extending the slack, and the entire wire mesh for rock fall prevention swells and deforms toward the rock, without deforming the rectangular frame mainly composed of support pieces. The bedrock can be compacted and a propulsion reaction force can be obtained.

According to the fourth aspect of the present invention, the wire mesh for preventing rock fall is dished into a space surrounded by the rectangular frame mainly composed of the support pieces, and the wire mesh for preventing rock fall is provided. Since the end of the four-sided peripheral edge rising outward is fixed to a rectangular frame mainly composed of support pieces, a dish-shaped wire mesh body is pressed by the rear gripper so that the four-sided peripheral portion serves as a fulcrum. The propulsion reaction force can be obtained by compacting the rock part without inverting the inside outward and bulging toward the rock part to deform the rectangular frame mainly composed of the support pieces.

[Brief description of the drawings]

FIG. 1 is a perspective view of a support piece on which a wire mesh body is stretched so as to be swellable and deformable by a pressing force;

FIG. 2 is a perspective view of a support piece having another structure;

FIG. 3 is a partially cutaway perspective view of the support piece having a further different structure, viewed from the inner peripheral surface side;

FIG. 4 is a longitudinal sectional side view showing a construction state of a support piece of still another structure;

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

FIG. 6 is a simplified longitudinal front view of a state in which the rear gripper is crimped to a rock part,

FIG. 7 is a simplified longitudinal front view showing a construction state of the support piece shown in FIG. 4;

FIG. 8 is a cross-sectional view of a state in which the rock piece is supported by the support piece,

FIG. 9 is a simplified vertical sectional front view showing a state in which the rear gripper is crimped to a rock part;

FIG. 10 is an enlarged cross-sectional view thereof,

FIG. 11 is a simplified vertical sectional front view for explaining a conventional example.

[Explanation of symbols]

 A Support body B Loose rock part A1-A4 Support piece 1 Main support piece 1a, 1b Main girder 1c, 1d Joint plate 2 Wire mesh body 2a, 2b to prevent rock fall Collapse 2c Loose part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21D 11/14 E21D 9/10

Claims (4)

(57) [Claims] 1. A support piece having a rock-fall prevention wire netting attached to an outer peripheral surface side of a rectangular frame-shaped support piece main body in which a joint plate is fixed between both ends of front and rear main beams curved in an arc shape. Supports the four sides of the rock mesh
It is mounted without sticking to the outer peripheral end face of the rectangular frame mainly composed of
And around the four sides of this wire mesh for rock fall prevention
The strip is superimposed on the supporting piece by superposing the strip on the edge.
This strip is fixed to the outer peripheral end face of the rectangular frame,
Between the outer edge of the rectangular frame and
支保piece of HoAmanetan edges, characterized in that the rock collapse prevention net member is present <br/> by bulging deformable is interposed outward from the outer circumferential surface of支保piece entity. 2. A joint between both ends of a front and rear main girder curved in an arc shape.
Peripheral surface of a rectangular frame-shaped support piece with a hand plate fixed
Support piece with wire mesh for rock fall prevention attached to the side
In the above, the rock fall prevention wire mesh body is provided outside the support piece body without fixing at least one edge of the four sides of the rock fall prevention wire mesh body to the support piece body.
支保piece, characterized in that it is placed in a state of out tension outward from bulging deformable支保pieces principal outward from the peripheral surface. 3. A joint between both ends of a front and rear main girder curved in an arc shape.
Peripheral surface of a rectangular frame-shaped support piece with a hand plate fixed
Support piece with wire mesh for rock fall prevention attached to the side
In at least two opposing edges of the four-sided edge of the rock fall prevention wire mesh body, a slack portion of an appropriate length is formed inward and a tip end of the two-edge is supported.
It is fixed to the main body, and the loosened part prevents the rock from collapsing
Wire mesh from the outer peripheral surface of the support piece to the outside
A support piece characterized by being swellable and deformable . 4. A joint between both ends of a front and rear main girder curved in an arc shape.
Peripheral surface of a rectangular frame-shaped support piece with a hand plate fixed
Support piece with wire mesh for rock fall prevention attached to the side
In the above, the rock-fall prevention wire mesh body is recessed in a dish-like shape in a space surrounded by a rectangular frame mainly composed of support pieces, and a four-sided peripheral portion rising toward the outside of the rock-fall prevention wire mesh body. Characterized in that the end of the support piece is fixed to a rectangular frame mainly comprising the support piece.