JP3236549B2 - 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.

[0002]

2. Description of the Related Art When a tunnel is excavated in a rocky ground by a tunnel excavator, the excavated tunnel wall surface may fall off or fall down.
As shown in FIG. 14, a plurality of rectangular frame-shaped support pieces 1 each having a joint plate fixed between both ends of a front and rear main girder curved in an arc shape.
Are successively joined and connected in the circumferential direction to assemble a ring-shaped support body A, and the support body A supports the entire tunnel excavation wall surface T.

In the case of assembling such a support body A in a skin plate of a tunnel excavator, in recent years, a facing type joint plate of the support pieces 1, 1 has been used using a swiveling type erector.
1c and 1d are sequentially joined to each other, and bolt holes and nuts drilled in the joint plates 1c and 1d are connected by bolts and nuts. Then, the ring-shaped support body A is assembled by turning in the circumferential direction of the skin plate. It is carried out.

[0004]

However, when the next support piece 1 is connected to the support piece supported by the revolving type erector, the joint plate of these support pieces 1 and 1 is connected.
Even when 1c and 1d are joined together, the joint surface is shifted in the front-rear direction or inward / outward direction, so that the bolt holes drilled in the joint plate cannot be accurately matched, and it takes time to connect with bolts and nuts. Therefore, there is a problem that the support body cannot be efficiently assembled.

The present invention has been made in view of such a problem, and an object of the present invention is to connect joint pieces by simply joining joint plates of these support pieces in a butt shape. It is an object of the present invention to provide a support piece in which bolt holes formed in a plate are easily and accurately matched with each other.

[0006]

According to a first aspect of the present invention, there is provided a support piece having a joint plate fixed between both ends of a front and rear main girder curved in an arc shape and attached to the joint plate. In a rectangular frame-shaped support piece with a bolt hole , a notch step is formed on the outer peripheral surface of one end of the front and rear main girder mainly of the support piece
Form the part, fit the base end of the guide plate into this notch step,
At the same time, the above
Have the form forms a structure in which the engaging step portion for engaging the projecting portion of the id plate.

In the supporting piece having the above structure, the invention according to claim 2 is that the base end of the guide plate is fitted and fixed to a notch step formed on the outer peripheral surface of one end of the front and rear main girder mainly comprising the supporting piece. The inner surface of the projecting portion of the guide plate projecting from the front and rear main girders is formed as an inclined surface inclined toward the outer surface toward the tip, and further, the inclined surface of the guide plate is formed on the outer peripheral surface of the other end of the front and rear main girders. And a locking inclined surface for locking is formed.

According to a third aspect of the present invention, there is provided a support piece having a structure different from the support piece according to the first aspect, wherein a joint plate is fixed between both ends of the front and rear main girders curved in an arc shape. The support piece in the form of a rectangular frame formed by drilling bolt holes in the joint plate has a structure in which a guide protrusion is protruded from the side end of at least one main girder of the support piece body in the circumferential direction. are doing.

According to the third aspect of the present invention, in the invention according to the fourth aspect , the support projecting plate protrudes from an outer peripheral surface of an end portion of the support piece main body where the guide projecting plate protrudes in a circumferential direction. It is characterized by doing.

[0010]

When assembling the support body by sequentially connecting the support pieces using the revolving type erector, the joint plate of the next support piece is abutted against the joint plate of the support piece previously supported by the erector. The guide plate projecting from the end of the front and rear main girder of one support piece is in sliding contact with the outer surface of the opposite end of the front and rear main girder of the other support piece, and these support pieces are mutually moved by the guide plate. The joint plates are accurately joined together while being restricted from shifting in the inner and outer surface directions. Therefore, the plurality of bolt holes formed in the joint plate can be easily matched with each other, so that the connection operation by bolts and nuts can be efficiently performed.

Furthermore, the支保form a cutout step portion on one end portion outer peripheral surfaces of the front and rear main girder piece mainly mating base end portion of the guide plate in the notch step portion, the fixed, other longitudinal main girder since forming the engaging step portion for engaging the projecting portion of the guide plate on the end portion outer peripheral surface, if the guide plate of one支保piece engaged the engagement step of the other支保piece, guide The outer peripheral surfaces of the front and rear main girder of the support piece can be flush with each other without the plate protruding outward. In addition, the widthwise end surface of the long side of the guide plate abuts against the wall surface of the step formed from the widthwise edge of the engaging step to the outer peripheral surface of the main girder, and the support pieces are brought together. The displacement in the front-rear direction can be prevented, and the joining operation can be performed more accurately.

Similarly, as described in claim 2 , a notch step is formed on the outer peripheral surface of one end of the front and rear main beams mainly composed of the support pieces, and the base end of the guide plate is fitted into the notch step. The inner surface of the projecting portion of the guide plate, which is fixed and protrudes from the front and rear main girders, is formed on an inclined surface inclined toward the outer surface toward the front end. By forming a locking inclined surface that locks the surface, if the guide plate of one support piece is engaged on the inclined surface of the other support piece, the guide plate can protrude outward. In addition, the outer peripheral surfaces of the front and rear main girders of the support piece can be flush.

[0013] In the support piece according to the third aspect,
Since the guide protruding plate protrudes from the side end of at least one main girder of the support piece main body in the circumferential direction, the joint of the next support piece to the joint plate of the support piece previously supported by the erector When the plates are butted against each other, the guide protruding plates projecting from the front and rear end faces of the front and rear main beams of one support piece slide in contact with the front and rear end faces of the opposite ends of the front and rear main beams of the other support piece, and The joint plates are accurately joined together while the displacement of these support pieces in the front-rear direction is restricted.

[0014] In this case, as described in claim 4 , if the supporting protruding plate that is engaged with the outer peripheral surface of the other end portion of the adjacent supporting piece is provided integrally between the outer ends of the guide protruding plate, the supporting pieces can be connected to each other. However, the displacement in the inward and outward directions is also restricted, so that joining can be performed more easily and accurately.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a supporting piece main body according to an embodiment of the present invention; FIG. A steel rectangular frame in which the longitudinal ends of the main girders 1a and 1b are integrally fixed by flat plate-like joint plates 1c and 1d, and a bar-shaped metal wire rod in a grid shape at an outer peripheral opening end of the rectangular frame. The joint plate 1c, 1d is inclined in the radial direction of the tunnel from the outer peripheral surface side of the support piece main body 1 toward the inner peripheral surface side. When the ring-shaped support body A is assembled, the joint plates 1c and 1d of the adjacent support pieces are entirely joined in a state where they face the center direction of the support body A. Further, a plurality of bolt holes 3 and 4 are formed in the joint plates 1c and 1d of the support piece main body 1 at regular intervals in the length direction. Similarly, a plurality of bolt holes 3a, 4a are formed in the front and rear main girders 1a, 1b at regular intervals in the length direction as necessary.

In the support piece main body 1 formed as described above, in the support piece shown in FIG. 1, a rectangular shape having a constant thickness is formed on the outer peripheral surface of one end of the front and rear main beams 1a and 1b of the support piece main body 1. The base ends of the guide plates 5, 5 are fixed by welding or the like, and protrude in the extending direction of the main girders 1a, 1b.
The width of the guide plate 5 is the same as or slightly narrower than the front and rear main girders 1a and 1b, and is curved in the length direction with the same degree of curvature as the front and rear main girders 1a and 1b.

In the support piece having the above-described structure, the guide plate 5 is directly fixed to the outer peripheral surface of one end of the front and rear main beams 1a and 1b, but the support piece shown in FIG. Cutout steps 6, 6 having a depth equal to the thickness of the guide plate 5 are formed on the outer peripheral surface of one end of 1a, 1b, and the base ends of the guide plate 5 are fixed to these cutout steps 6 by welding or the like. On the other hand, engaging step portions 7, 7 for engaging the projecting portions of the guide plates 5, 5 are formed on the outer peripheral surfaces of the other ends of the front and rear main beams 1a, 1b. The depth of the engaging step 7 is equal to the thickness of the guide plate 5.

The support piece shown in FIG. 3 is a modification of the support piece shown in FIG. 2, and has a depth equal to the thickness of the guide plate 5 on one end outer peripheral surface of the front and rear main girders 1a and 1b of the support piece main body 1. Notch step portions 6 are formed, and the base ends of the guide plate 5 are fixed to these notch step portions 6 by welding or the like, respectively, and the guide plate 5 protrudes from the front and rear main beams 1a, 1b. The inner surface of the portion is formed as an inclined surface inclined toward the outer surface toward the front end, and the outer surface of the other end of the front and rear main beams 1a, 1b has the same cross-sectional shape as the projecting portion of the guide plate 5 and the bottom surface is formed of the guide plate 5
Engaging step 7 'having a locking inclined surface 7b for slidingly contacting the inclined surface
Is formed. Other structures are the same as the above-mentioned support piece.

In the above embodiment, the support piece having the structure in which the guide plate 5 is fixed to the outer peripheral surface of one end of the front and rear main beams 1a and 1b is shown. However, the support piece shown in FIG. Guide projection plates 5A, 5A each having a rectangular front surface and a certain thickness are projected from front and rear end surfaces at one end portions of the main girders 1a, 1b. That is, the base ends of the guide protruding plates 5A, 5A are fixed to the front and rear end surfaces at one end of the front and rear main girders 1a, 1b by welding or the like, and these guide protruding plates 5A, 5A are spaced apart from each other by the width of the support piece main body 1. The main girders 1a, 1b are provided so as to protrude in the direction of extension, and the opposing surfaces of the guide plates 5A, 5A are configured so that the front and rear main girders 1a, 1b of the adjacent support pieces are sandwiched between the other end front and rear end surfaces.

Further, the guide protruding plates 5A, 5A are connected to the front and rear main beams 1a,
Although it may be fixed directly to the front and rear end faces of 1b by welding or the like, as shown in the figure, a notch step 6A equal to the thickness of the guide protruding plate 5A is formed on the front and rear end faces of the front and rear main girders 1a and 1b. In addition, the base end of the guide protruding plate 5A is fixed to the notch step 6A in a fitted state, and the guide protruding plate 5A can be engaged with the front and rear end surfaces at the other end of the front and rear main beams 1a, 1b. An engaging step 7A is formed. In this case, although not shown, the width of the guide protruding plate 5A is formed to be smaller than the width of the front and rear main girders 1a and 1b, while the engaging step 7A is formed in a groove-shaped engagement in which the guide protruding plate 5A can be fitted. If it is formed in the joint portion, when the guide protruding plate 5A protruding from one support piece is fitted into the engagement step portion of the other support piece, both are restricted not only in the front-back direction but also in the inward and outward directions. It can be joined in a state. In addition,
The guide plate 5A may protrude from only one main girder.

FIG. 5 shows the support piece shown in FIG. 4 between the outer ends of the projecting portions of the guide protruding plates 5A, 5A projecting from the main beams 1a, 1b, ie, the end face on the outer peripheral surface side of the support piece main body 1. A support protruding plate 5B to be engaged with the outer peripheral surface of the other end portion of the adjacent support piece is integrally provided therebetween. Note that the support protruding plate 5B may not be integral with the guide protruding plates 5A, 5A.

FIG. 6 shows a tunnel excavator 10, in which a support member 12 is disposed integrally with a 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 54 and being vertically expandable and contractable 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 connected between the upper and lower arms 17, and a cylindrical sliding frame
The sliding frame 19 has a structure in which a push-up jack 20 is fixed to the upper surface of the sliding frame 19.

Further, a swivel type erector B is provided in the skin plate 11 of the tunnel excavator 10. In the revolving type erector B, an erector ring 8 is rotatably disposed around a beam body portion on the front side of the sliding frame 19 at a predetermined interval from the inner peripheral surface of the skin plate 11. A rack 8c formed on the inner peripheral surface of the erector ring 8 is engaged with a pinion 9a fixed to a rotary shaft of a rotary drive motor 9 installed on the beam member 14, and the erector ring 8 is rotated by the rotary drive motor 9. As shown in FIG. 7, the erector ring 8 is provided with an erector head 8a for removably engaging with the support piece, and a support piece support bracket 8b is provided on the outer peripheral surface. Is mounted.

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
As is well known, it is disposed on the rear side of the beam body 14 protruding rearward from the lower side of the beam receiver 21 slidable relative to the beam body 14 on both sides of the tunnel wall T. The rear grippers 17, 17 and the rear side portions of the support member 21 are connected to each other by the propulsion jacks 18, 18, respectively. Further, the sliding frame 19 and the beam receiver 21 are connected via a connecting jack 22. The earth and sand excavated by the cutter plate 13 is discharged backward by an appropriate carrying-out means such as a conveyor (not shown).

In order to assemble the ring-shaped support body A by sequentially connecting a plurality of support pieces using the revolving erector B in the skin plate 11 of the tunnel excavator 10 configured as described above, first, Then, one support piece 1A is supplied on the lower peripheral portion of the skin plate 11, and the support piece is supported by the erector head 8a as shown in FIG. At this time, one end side of the support piece 1A, that is, the guide plate 5 or the guide protruding plate 5A faces the receiving side of the next support piece 1B and is supported by the erector head 8a. Thereafter, the rotary member 9 is rotated clockwise in FIG. 5 by the rotary drive motor 9 to move the support piece 1A upward along the inner peripheral surface of the skin plate 11 by a predetermined circumferential length, and then to the position. To hold.

Next, the next support piece 1B is carried onto the lower peripheral portion of the skin plate 11, and the other end-side joint plate 1d is supported by the erector head 8a. As shown in FIG. 8 (b), these support pieces 1a are opposed to the joint plate 1c on the side where the 5A is projected.
The joint plates 1c and 1d of A and 1B are joined to each other.

At this time, in the case of a support piece having guide plates 5 and 5 protruding from one end outer peripheral surface in the extending direction of the front and rear main girders 1a and 1b, as shown in FIG. The support piece 1B is guided by the guide plates 5, 5 while the outer peripheral surfaces of the other end portions of the front and rear main girders 1a, 1b of the support piece 1B to be joined on the guide plates 5, 5 of 1A are received. Support piece
When the support pieces 1A and 1B are moved toward the 1A side, the supporting pieces 1A and 1B are easily and accurately joined to each other while being restricted from shifting inward and outward by the guide plates 5 and 5. , 1d are aligned with the bolt holes 3, 4. By inserting bolts between these bolt holes 3 and 4 and screwing nuts together, the support pieces 1A and 1B are integrally connected and the support piece 1B is supported by the support metal 8b standing upright on the electoring ring. .

In such a connecting means, as shown in FIG. 2, the guide plates 5, 5 are provided on notch step portions 6 formed on the outer peripheral surfaces of the one end portions of the front and rear main beams 1a, 1b of the support piece main body 1. When the base end is fixed, as shown in FIG. 10, the next support piece 1B to be joined is placed on these guide plates 5, 5 of the support piece 1A supported by the erector head 8a.
The engaging steps 7, 7 provided on the main girders 1a, 1b at the other end opposite to each other are aligned, and the engaging steps 7, 7 are engaged with and received by the guide plates 5, 5, respectively. When the support piece 1B is moved to the support piece 1A side while being guided by the plates 5, 5,
The support plates 1A, 1B are prevented from shifting inward and outward from each other by the guide plates 5, 5, and the engaging steps 7
The joint plates 1c and 1d facing each other are accurately joined together while the displacement in the front-rear direction is also restricted by the wall surface 7a, and the bolt holes 3 and 4 formed in the joint plates 1c and 1d coincide with each other and the guide plates 5 and 5 can be flush with the outer peripheral surfaces of the front and rear main girders 1a, 1b.

Similarly, even when the inner surfaces of the protruding portions of the guide plates 5, 5 whose base ends are fitted and fixed to the notch step portions 6 are formed on the inclined surfaces 5a as shown in FIG. , FIG. 11
As shown in the figure, the support piece to be joined on the inclined surface 5a
By joining the joint plates 1c, 1d of the two support pieces 1A, 1B in a state where the locking inclined surface 7b of the engaging step portion 7 'provided at the opposite end of the 1B is engaged, the inside and outside directions and the front and rear The bolt holes 3, 4 drilled in the joint plates 1c, 1d are accurately matched while the deviation of the direction is regulated, and the outer surfaces of the guide plates 5, 5 are aligned with the outer peripheral surfaces of the front and rear main beams 1a, 1b. Can be in one state.

On the other hand, as shown in FIG. 4, a support piece in which guide protruding plates 5A, 5A protrude from front and rear end faces at one end of front and rear main beams 1a, 1b of the support piece main body 1 is shown in FIG.
As shown, when the opposite end of the next support piece 1B is fitted between the guide protruding plates 5A, 5A protruding from the support piece 1A supported by the erector head 8a, the front and rear end faces of this opposite end are changed. The guide protruding plates 5A and 5A are slid in contact with the opposing surfaces of the guide protruding plates 5A and 5A, and guided while being prevented from being deflected in the front-rear direction. Bolt holes 3 and 4 are the same. In this case, the width of the guide protruding plate 5A is formed smaller than the width of the front and rear main beams 1a, 1b, while the engaging step 7A is formed in a groove-shaped engaging step in which the guide protruding plate 5A can be fitted. If this is done, the joining can be performed while restricting not only the front-back direction but also the displacement in the inside and outside directions.

In the case of the support piece shown in FIG. 5,
As shown in FIG. 13, the guide protruding plate 5A projecting from one end of the support piece 1A supported by the erector head 8a,
The displacement of the support piece 1B to be joined by the 5A in the front-rear direction is regulated and the outer peripheral surface of the opposite end of the support piece 1B is formed on the support protrusion 5B provided integrally between the outer ends of the guide protrusions 5A and 5A. The joint plates 1c and 1d are accurately joined to each other while being received and being restricted from moving inward and outward.

After connecting the support pieces 1A and 1B in the circumferential direction of the skin plate 11 as described above, the rotary drive motor 9 again rotates the elector ring 8 clockwise in FIG. The supporting pieces 1A and 1B are moved upward along the inner peripheral surface of the skin plate 11 by a predetermined circumferential length, and then held at that position.

Next, the next support piece 1C is carried into the lower peripheral portion of the skin plate 51, and the other end-side joint plate 1d is connected to the support piece 1A. The guide plate 5 or the guide protruding plate 5A of the support piece 1B. FIG. 8 shows the guide plate 5 or the guide protrusion plate 5A as a guide.
As shown in (c), the opposed joint plates 1c, 1d of the support pieces 1B, 1C are joined in the same manner as described above, and these joint plates 1B, 1C are joined.
The bolt holes 3 and 4 formed in c and 1d are aligned with each other, connected by bolts and nuts, and the support piece 1C is supported by the support bracket 8b provided upright on the electoring ring.

As described above, the ring-shaped support body B is assembled by connecting the support plates to the joint plates facing each other sequentially using the revolving type erector B, and then the beam member is formed.
The sliding frame 19 is advanced by the connecting jack 22 along 14 to move the push-up jack 20 on the sliding frame 19 to the support A in the skin plate 11, and the support A is moved by the push-up jack 20. While supporting the inner surface of the upper peripheral portion, the erector head 8a and the support fitting 8b are removed from the support piece. Next, the sliding frame 19 is moved rearward from the skin plate 11 so that the rear end face of the support A supported by the push-up jack 20 abuts on the front end face of the existing support A supporting the tunnel wall surface T, The outer diameter of the support body A is increased by interposing a jack or the like between the support pieces of the support body A which are separated from each other, so that the outer peripheral surface of the support body A is brought into close contact with the tunnel excavation wall surface T to support the tunnel excavation wall surface T. . In addition, it is not necessary to provide the fall prevention material 2 in all of the support pieces constituting the support body A, and the fall prevention material 2 is stretched on at least the support piece supporting the upper peripheral side of the tunnel excavation wall surface T. It is good.

In the excavation by the tunnel excavator 10, the rear grippers 17, 17 are pressed against both side surfaces of the tunnel wall T, and then the rear support 16 is contracted and separated from the bottom surface of the tunnel wall T. The front gripper 15 is excavated on the wall T while the reaction force is supported on the tunnel wall T via the rear gripper 17 by extending
It is excavated by the cutter plate 13 while being in sliding contact with. After excavating a tunnel of a certain length, the front gripper 15 is firmly 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. Then, the propulsion jack 18 is contracted to advance the rear gripper 17 along the beam member 14 to the next crimping position.

In the above-described embodiment, the collapsing prevention members 2 are stretched on all the support pieces. However, when assembling the support body A in combination with the support pieces that have not been stretched, the support body A is required. The support piece without the collapsing prevention member 2 has the same structure as described above.

[0037]

As described above, according to the support piece according to the first aspect of the present invention, a joint plate is fixed between both ends of the front and rear main girders curved in an arc shape, and a bolt hole is formed in the joint plate. in the rectangular frame-shaped支保piece formed by the previous支保piece main
A notch step is formed on the outer peripheral surface of one end of the rear main girder, and this notch step
The base end of the guide plate is fitted and fixed to the
The protrusion of the guide plate is engaged with the outer peripheral surface of the other end of the rear main girder.
When the support body is assembled by sequentially connecting the support pieces using a swivel-type erector, one of the support pieces protrudes from the end of the front and rear main girder. The opposite end of the next support piece can be easily and reliably abutted along this guide plate as the receiving side of the guide plate, and the guide plate causes a step or deviation at the opposite end of the support piece. The joint plates of these support pieces can be accurately joined together while restricting the number of bolt holes drilled in the joint plate. The connecting operation can be performed efficiently.

Further, the base end of the guide plate is fitted and fixed in a notch step formed on the outer peripheral surface of one end of the front and rear main girder mainly composed of the support piece , and the outer peripheral surface of the other end of the front and rear main girder. The guide plate of one support piece is engaged with the engagement step of the other support piece, so that the guide plate is moved outward. The outer peripheral surfaces of the front and rear main girders of the support piece can be flush with each other without protruding from the support piece, and are formed from the widthwise edge of the engaging step portion toward the outer peripheral surface of the main girder. The end face on the long side of the guide plate abuts against the wall surface of the step portion, so that it is possible to reliably prevent the support pieces from being displaced in the front-rear direction, so that the joining operation can be performed more accurately.

According to the second aspect of the present invention, the base end of the guide plate is fitted and fixed to the notch step formed on the outer peripheral surface of one end of the front and rear main girder of the support piece. The protrusions of the guide plate projecting from the front and rear main girders are formed on the inclined surface inclined toward the outer surface toward the tip, while the inclined surface of the guide plate is locked to the outer peripheral surface of the other end of the front and rear main girder. Since the stop inclined surface is formed, the guide plate of one support piece can be smoothly engaged along the inclined surface of the other support piece, and the guide plate does not protrude outward. The outer peripheral surfaces of the front and rear main girder of the support piece can be flush.

According to the third aspect of the present invention, since the guide projecting plate protrudes in the circumferential direction from the side end of at least one main girder of the support piece main body, the support supported by the erector first is provided. When the opposing joint plate of the next support piece is abutted against the joint plate of the piece, the guide protruding plate projecting from the front and rear end faces of the front and rear main girder of one support piece is located at the front and rear main girder of the other support piece. Sliding contact is made with the front and rear end surfaces of the opposing ends, and the joint plates can be accurately joined to each other while the supporting pieces are restricted from shifting in the front-rear direction by the guide protruding plates. A plurality of bolt holes can be easily and accurately matched with each other, so that connection work with bolts and nuts can be efficiently performed.

[0040] In this case, as described in claim 4, between the outer end of the guide veneer, if provided with a support projecting plates engaged with the other end portion outer peripheral surfaces of adjacent支保piece,支保piece with each other inside and outside The displacement in the direction is also regulated, so that joining can be performed more easily and accurately.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view of the support piece of the present invention viewed from the inner surface side,

FIG. 2 is a simplified perspective view of another support piece of the present invention viewed from the inner surface side;

FIG. 3 is a simplified perspective view showing a modification of FIG. 2;

FIG. 4 is a simplified perspective view of another support piece of the present invention as viewed from the inner surface side;

FIG. 5 is a simplified perspective view showing a modification of FIG. 4;

FIG. 6 is a simplified longitudinal side view of a tunnel excavator on which a support body is being constructed,

FIG. 7 is a simplified front view of a support formed on the electoring ring,

FIG. 8 is a simplified front view showing a support body assembling process;

FIG. 9 is a simplified front view showing a connected state of the support pieces of FIG. 1;

FIG. 10 is a simplified front view showing a connected state of the support pieces of FIG. 2;

FIG. 11 is a simplified perspective view showing a connected state of the support pieces of FIG. 3;

FIG. 12 is a simplified perspective view showing a connected state of the support pieces of FIG. 4;

FIG. 13 is a simplified perspective view showing a connected state of the support pieces of FIG. 5;

FIG. 14 is a simplified front view of a conventional support body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support piece main body 1a, 1b Main girder 1c, 1d Joint plate 2 Collapse prevention material 3, 4 Bolt hole 5 Guide plate 7 Engagement step A Supporting body

Claims (4)

(57) [Claims] 1. A rectangular frame-shaped支保piece formed by drilled bolt holes and該継hand plate fixing a joint plate across the front and rear main girder was curved in an arc shape, the front and rear main of支保piece main
A notch step is formed on the outer peripheral surface of one end of the girder, and this notch step
The base end of the guide plate is fitted and fixed, and
The protrusion of the guide plate is engaged with the outer peripheral surface of the other end of the spar.
A support piece characterized by forming an engagement step . 2. The guide plate, wherein the base end of the guide plate is fitted and fixed to a notch step formed on the outer peripheral surface at one end of the front and rear main girder of the support piece main body, and protrudes from the front and rear main girder. The inner surface of the projecting portion is formed as an inclined surface inclined toward the outer surface toward the tip, and further, a locking inclined surface for locking the inclined surface of the guide plate is formed on the outer peripheral surface of the other end of the front and rear main beams. The support piece according to claim 1, wherein: 3. A rectangular frame-shaped support piece in which a joint plate is fixed between both ends of a front and rear main girder curved in an arc shape and a bolt hole is formed in the joint plate, wherein at least one of the support piece main bodies is provided. A support piece characterized in that a guide plate is protruded from a side end of a main girder in a circumferential direction. 4. The support piece according to claim 3 , wherein a support protrusion is protruded in a circumferential direction from an outer peripheral surface of an end portion where the guide protruding plate mainly composed of the support piece protrudes. .