JPH09291799A - Inner formwork for lining tunnel wall surface with concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner formwork which is assembled along the drilled wall of a tunnel, assembled and disassembled smoothly and efficiently, and can be accurately assembled. SOLUTION: In this inner formwork A, male formwork members 1 of which both end faces are formed into outward inclined end faces 1a, and female formwork members 2 of which both end faces are formed into inward inclined end faces 2a are alternately arranged in the circumferential direction of a tunnel, so as to form a circular ring shape. In addition to this, opposed end parts of the adjoining male and female formwork members 1, 2 are integratedly connected together through a connecting rod 3, and the inner formwork is constituted so that by pulling the male formwork members 1 to the inside of a tunnel by means of an expansion/contraction device, they are separated from between the femal formwork members 2, 2 so as to contract the diameter of the inner formwork A, and by pushing out the male formwork members 1 by means of the expansion/contraction device, the male formwork members 1 are fitted while spreading between the female formwork members 2, 2 through the connecting rods 3 so as to spread the diameter of the inner formwork A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner formwork for forming a lining of cast-in-place concrete on a wall surface of a tunnel excavated by a shield method.

[0002]

2. Description of the Related Art In the shield construction method, concrete lining is performed on the excavated wall surface every time a tunnel of a certain length is excavated by the tunnel excavator. The formwork is assembled in an annular shape along the excavation wall surface in accordance with the front end surface of the previously assembled inner formwork, and concrete is placed between the inner formwork and the excavation wall surface for lining work. At the same time, the front end surface of the inner formwork is supported by the reaction force of the tunnel excavator and is being advanced.

As such an inner formwork for concrete lining, conventionally, for example, as described in Japanese Patent Application Laid-Open No. 4-216799, a circular arc shape formed by dividing the inner wall of the tunnel wall in the circumferential direction is used. It is known that a curved split mold piece and a key mold piece having a triangular cross section to be interposed between opposed end surfaces of adjacent split mold pieces are known.
After the key form pieces are pivotally attached to both ends of each divided form piece, the divided form pieces without the key form pieces are arranged at predetermined intervals in the tunnel circumferential direction on the tunnel wall surface. Then, insert the split form pieces with the key form piece into the above-mentioned interval, and form an annular inner form frame with these multiple form parts, and rotate the key form piece. Then, after interposing it in the triangular space formed between the opposite ends of the split mold piece, the end portion is pivotally attached to the split mold piece to fix the inner mold, and then, We are placing concrete.

[0004]

However, according to the inner formwork as described above, a plurality of split formwork pieces are separated from each other, and the key formwork pieces are attached to and detached from these split formwork pieces. There is a problem in that the work is required and the assembling work and the dismantling work require a great deal of time and work efficiency is reduced. Furthermore, after placing a plurality of split form pieces in the circumferential direction of the tunnel wall with an interval allowing the next split form piece to intervene, the next form part is pivotally attached with a key form piece. Since the mold pieces are inserted into the space, it is difficult to align them accurately, and there is a gap in the tunnel length direction between the facing end faces of the adjacent divided mold pieces, or in the radial direction of the tunnel. However, there is a problem that a step is generated and the inner formwork cannot be assembled accurately.

The present invention has been made in view of the above problems, and an object thereof is to make it possible to assemble divided form members accurately and efficiently along a wall surface for excavating a tunnel. An object of the present invention is to provide an inner formwork for concrete lining, which enables formation of a good concrete lining and also allows easy disassembly and movement.

[0006]

In order to achieve the above object, the present invention provides a movable carriage which moves in the tunnel length direction on a beam arranged at the center of a tunnel, and is installed on this movable carriage. An inner formwork for concrete lining that is detachably supported by the expanding and contracting device and expands and contracts in the radial direction of the tunnel, with both end faces inclining in a direction that narrows from the outer peripheral side toward the inner peripheral side. A plurality of female mold members formed on the inclined surface and both end faces can be joined to the inwardly inclined surface of the female mold member by inclining both end surfaces in a direction that becomes wider from the outer peripheral side toward the inner peripheral side. A plurality of male form members formed on the outwardly inclined surface, and these female form members and male form members are alternately arranged in the tunnel circumferential direction and adjacent male and female form members are formed. The opposite ends are rotatably connected with a connecting rod, and the male and female mold parts are connected. The male mold member is configured to move in the tunnel radial direction by the telescopic device in.

Further, in the invention described in claim 2, in the inner formwork for concrete lining of the tunnel wall surface, a link mechanism is arranged in the female form member, and the fulcrum of the link mechanism is a female form member. And the free end of the link mechanism is pivotally attached to the connecting rod so as to join the male and female form members without colliding with each other.

[0008]

The inner formwork of a plurality of rings is assembled on the excavation wall face excavated by the tunnel excavator, and the concrete cast between the excavation wall face and the inner formwork is cured until it hardens. The tunnel excavator takes a reaction force to the front end surface of the inner formwork at the forefront and excavates a tunnel with a length of one ring of the inner formwork. The formwork is disassembled, and the inner formwork is moved to the rear end of the tunnel excavator by a moving carriage that travels on the beam, and is assembled along the excavated wall surface.

In the dismantling of the inner formwork in the above work steps, when all the expansion and contraction devices connected to the male formwork members are simultaneously contracted, all the male formwork members are disengaged from the concrete lining surface and their outwardly inclined end faces are removed. It is separated from the facing inwardly inclined end faces of the adjacent female form members. At this time, since both ends of the male mold member are rotatably connected to the opposite ends of the female mold member by connecting rods, the male mold member moves as the male mold member moves toward the tunnel center. The female form members connected to both ends of the frame member are separated from the concrete lining surface toward the tunnel center side while being pulled together by the connecting rods, and when the male form member is completely inwardly separated from the female form member, Both ends of the adjacent female form members come into contact with each other, and the annular form frame formed by these female form members has a diameter smaller than that of the assembled inner form member.

In this way, by moving the movable carriage forward along the beam in a state in which each male form member in the reduced inner formwork is supported by the telescopic device, the reduced inner formwork is moved to the rear of the tunnel excavator. The inner formwork is conveyed to the end part, and the inner formwork is expanded at that position to join the front end face of the previously assembled inner formwork to the rear end face of the inner formwork. This assembly is performed by extending the telescopic device. That is, when the telescopic device is extended, the male form member moves toward the excavation wall surface, and along with this movement, the adjacent female form member member is pushed and expanded through the connecting rod while moving toward the excavation wall surface and expanding. The male form member is inserted between the facing end faces of the adjacent female form member members, and the inner formwork whose diameter is expanded when both inclined end faces of the male form member are joined to the facing inclined end faces of the female form member is assembled. It goes up.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to the drawings. A is an annular shape having an outer diameter equal to the inner diameter of a concrete lining C lining a tunnel excavation wall B. The inner frame is composed of a plurality of male frame members 1 and female frame members 2, and these male frame members 1 and female frame members 2 are arranged alternately in the circumferential direction of the tunnel T. And the connecting rods 3 and 3 having a constant length are provided between the opposing ends of the male and female mold members 1 and 2.
Is rotatably connected by.

The lengths of the male and female form members 1, 2 corresponding to the tunnel length direction are formed to have the same length,
The circular arc width corresponding to the circumferential direction of the tunnel makes the female frame member 2 wider than the male frame member 1. Male form member 1
Is a slanted end surface whose both end surfaces are inclined outward so that the width of the male form member 1 in the tunnel circumferential direction gradually increases from the outer peripheral side to the inner peripheral side, that is, from the excavation wall surface B side into the tunnel T. 1a, 1a, and the entire shape is formed into an isosceles trapezoidal shape. On the other hand, the female form member 2 has inclining end faces 2a, 2a inclined inwardly so that the width of the female form member 2 in the tunnel circumferential direction becomes gradually narrower from the outer peripheral side toward the inner peripheral side. Is formed. The outwardly inclined end face 1a of the male mold member 1 and the inwardly inclined end face 2a of the female mold member 2 are formed so as to be in surface contact with each other. Since the male frame member 1 is inserted between the facing inwardly inclined end faces 2a, 2a of the adjacent female frame members 2, 2 on both ends thereof, the male frame member 1 is called a male frame member. Since the mold member 2 is the side that receives the male mold member 1, it is called a female mold member.

The male and female formwork members 1 and 2 are made of metal plates such as steel plates. That is, the outer peripheral surface facing the excavation wall surface B is composed of the mold plates 1b and 2b curved along the excavation wall surface B as shown in FIGS. 2 and 3, and the tunnel is formed from the four edges of the mold plates 1b and 2b. Front and rear wall plates with a certain height toward the inside 1
c, 2c and both side wall plates on which the inclined end faces 1a, 2a are formed are integrally fixed, and a reinforcing material (not shown) is fixed inside thereof, if necessary.

The structure of the connecting rod 3 for connecting the opposite ends of the male and female mold members 1 and 2 is such that the brackets 4 are provided on the inner and outer front portions of the mold plates 1b and 2b at the opposite ends of the male and female mold members 1 and 2. 4;
5 and 5 are fixed, and both ends of the front and rear connecting rods 3 and 3 are pinned to the opposing brackets 4 and 5 of the male and female frame members 1 and 2, respectively.
The wall plates, which are rotatably pivoted by 6a and 6b, and on which the inclined end surfaces 1a and 2a of the male and female frame members 1 and 2 are formed, are notched 7 so that the connecting rod 3 can be rotated. ing. In addition,
The connecting rod 3 has a male frame member 1 rather than a pivot portion on the female frame member 2 side.
The male and female mold frame members 1 and 2 are connected so that the pivotal portion on the side is located closer to the inside of the tunnel, and the opposite end surfaces of the male and female mold frame members 1 and 2 are reliably joined together.

When the male frame member 1 is inserted between the facing inwardly inclined end faces 2a, 2a of the adjacent female frame members 2, 2, the male frame member 1 is moved toward one of the female frame members 2. In order to prevent it from moving and becoming impossible to insert, the male frame member 1
There is provided a rotation angle restriction means for the connecting rod 3 so that one end of the connecting rod 3 pivotally attached to the female frame member 2 is always positioned inside the other end. As shown in FIG. 4, this restricting means causes one end of the connecting rod 3 pivotally attached to the end of the male frame member 1 by a pin 6 to project from the pivotal portion, and elastic members are provided on both end surfaces of the projecting end. The stopper members 8a and 8b are made to adhere to each other so that the inner stopper member 8a abuts on and receives the receiving surface portion 9 provided on the inner wall of the male frame member 1. .

Therefore, as shown in the figure, the male frame member 1
Is inwardly separated from the female mold member 2, one stopper member 8a abuts against and is received by the receiving surface portion 9 of the male frame member 1, and the connecting rod 3 is further rotated. Is blocked,
The one end pivotal portion is always positioned closer to the inwardly inclined end surface 2a than the other end pivotal portion on the female frame member 2 side, and the female frame members 2 and 2 face each other. When the outwardly inclined end faces 1a, 1a of the male frame member 1 are joined to the inwardly inclined end faces 2a, 2a and completely inserted and interposed, the other stopper member
8b is brought into contact with the inner wall surface of the outwardly inclined end surface 1a of the male mold member 1,
It is configured to be received. In order to configure the expandable / contractible inner mold form A by a plurality of male and female mold frame members 1 and 2 connected by the connecting rod 3, as shown in the drawing, at least one pair of male and female mold frame members 1 and 2 is formed. It is desirable to divide into 6 pairs or more.

The inner mold form A constructed in this manner is shown in FIGS.
As shown in FIG. 6, the vehicle is supported behind the tunnel excavator S by the telescopic device D installed on the moving carriage E and is transported in the tunnel length direction. That is, the rear end of the tunnel excavator S is connected to the front end of a long beam F arranged at the center of the tunnel, and a movable carriage E integrally provided with the expansion device D is moved back and forth along the beam F. It is configured to let. The beam F is a hollow tube having a polygonal cross-section (a hexagon in the figure) having a number of sides corresponding to the number of the male frame members 1, and the length thereof is assembled to the rear of the tunnel excavator S. And the length of the inner formwork A for one ring is added to the sum of the lengths of the inner formwork A of the plurality of rings, and the rear end thereof is on the inner surface of the concrete lining C. It is movably supported in the length direction of the tunnel by the supporting leg member with a wheel 10 that rolls. The beam F is connected to the rear end of the tunnel excavator S so as to move forward integrally with the tunnel excavator S, but the front and rear wheels are separated from the tunnel excavator S. It may be configured so as to move independently in the tunnel length direction via the attached supporting leg members.

In the movable carriage E which moves back and forth along the beam F, a regular hexagonal short tubular frame 11 in which the cross-sectional shape of the beam F is enlarged is concentrically covered with the beam F, and its three sides are framed. A leg 12 with a wheel is integrally provided on the inner surface of the part and the wheel
It has a structure in which 13 is rotatably supported on the flat surface of the beam F. Although not shown, the wheels 13 are rotated by a motor drive to move the moving frame E in the longitudinal direction of the beam F back and forth.

The telescopic device D is installed on the outer surface of the frame portion 11a forming each side of the hexagonal frame body 11 of the movable carriage E so as to correspond to each male frame member 1 of the inner frame A. ing. The concrete structure is that the dovetail-shaped guide grooves 14 are formed parallel to the longitudinal direction on both sides of the center of each frame 11a.
The bottom portions of the front and rear sliding pieces 15 and 16 are slidably engaged with the pair of support rods 14, and a pair of support rods are provided corresponding to the guide grooves 14 and 14.
17 and 18 are crossed to form a pantograph shape and connected so as to be movable up and down, and the base ends of these support rods 17 and 18 are rotatably connected to the front and rear sliding pieces 15 and 16. While
The distal end portion is configured to be detachably connected by a connecting pin 21 to a connecting hole formed in the brackets 19 and 20 projecting from the front and rear portions of the inner surface of the corresponding male frame member 1. Further, the front and rear sliding pieces 15 and 16 are jacks arranged on the frame portion 11a.
The support rods 17 and 18 connected to the male frame member 1 are connected to each other by the expansion and contraction of the jack 22 so that the support rods 17 and 18 are connected to the male frame member 1 to expand and contract.

It should be noted that, without being limited to such an expansion / contraction device D, a jack is installed on each frame portion of the moving carriage E, and the rod end of this jack can be detachably attached to the inner surface of the male frame member 1. Alternatively, an appropriate device such as a structure for connecting to the above or a telescopic device using a screw mechanism may be used. In addition, the ends of the support rods 17 and 18 of the telescopic device D are attached to the bracket of the male frame member 1.
As means for detachably connecting to 19 and 20, in addition to the above-mentioned pin connection, a gripping means that operates automatically is attached to the tip ends of the supporting rods 17 and 18, and the male form member is held by this gripping means. The first brackets 19 and 20 may be configured to be detachably held.

Next, a method of constructing a concrete lining on the tunnel excavation wall surface B using the inner formwork A constructed as described above will be described. Until the concrete lining the wall surface excavated by the tunnel excavator S hardens, the inner form A
As shown in FIG. 5, the inner formwork A is assembled from the rear end of the tunnel excavator S toward the rear of the tunnel so that the front and rear end faces are integrally joined to each other. Curing the cast concrete.

The tunnel excavator S excavates the tunnel T by rotating the cutter plate 23 and extending the rod end of the propulsion jack 24 to the front end surface of the innermost form A at the front with a reaction force. When the excavation of the length of one ring of the inner mold is completed, the inner mold A at the rearmost portion where the hardening of the concrete is completed is dismantled. This dismantling work is performed using the inner mold A
After uncoupling the inner inner frame A on the front side, which is connected to the vehicle by bolts, etc., and moving the moving carriage E backward along the beam F to the position of the innermost mold A at the rearmost part, Support rod 1 for the telescopic device D installed on the frame 11a
7 and 18 are extended by the operation of the jack 22, and the tips are connected and fixed to the brackets 19 and 20 provided on the front and rear portions of the inner surface of the male form member 1 of the inner form A, and then the expansion device D is contracted. It is carried out by

That is, after connecting the tips of the support rods 17 and 18 of the expansion / contraction device D to the male mold member 1 of the inner mold A, each expansion / contraction device D is connected.
When the support rods 17 and 18 are contracted toward the center of the tunnel, the male form member 1 is pulled toward the center of the tunnel and separated from the inner surface of the concrete lining C, and both ends thereof are inclined outward and the inclined end surfaces 1a are adjacent to each other. Inward end face of female form member 2
When the female form members 2 and 2 adjacent to each other are moved away from the concrete lining C and are separated from the concrete lining C, the female form members 2 and 2 adjacent to each other are pulled toward each other via the connecting rod 3 in accordance with the separation. Reduce the diameter. As shown in the phantom line in FIG. 1, when each male mold member 1 reaches a position distant inward from the tunnel between the facing inwardly inclined end faces 2a, 2a of the adjacent female mold members 2, 2, a female mold member is formed. The opposing ends of the frame members 2 and 2 do not come into contact with each other, and the diameter of the entire inner mold form A is not further reduced. The outer diameter of the inner formwork A thus reduced in diameter is smaller than the inner diameter of the inner formwork A whose diameter has been expanded.

Next, the movable carriage E is moved to the rear end side of the tunnel excavator S along the beam F, and the inner formwork A having a reduced diameter is made to correspond to the excavated wall surface B. Since the outer diameter of the reduced inner formwork A is smaller than the inner diameter of the existing inner formwork A assembled on the excavation wall surface B, the reduced inner formwork A is replaced by the existing inner formwork A. Moving trolley E inside the tunnel surrounded by
It can be transported smoothly while being supported.

When the movable carriage E advances to the position of the excavation wall surface B, the telescopic device D is extended at that position to expand the inner formwork A along the excavation wall surface B, and the existing inner mold assembly previously assembled. Assemble the front end face of the frame A while joining the rear end face thereof. At this time, when the tunnel excavator S is excavating an oblique shaft for laying a pressure pipe for power generation obliquely upward, a plurality of propulsion jacks mounted in the rear end portion of the tunnel excavator S. The rod end of 24 is received by the front end face of the existing inner formwork A assembled earlier to prevent the tunnel excavator S from slipping down, and also when the tunnel excavation in the shield construction method is performed, the soil of the face is cut. As the excavator retracts due to pressure or water pressure, the rod end of the propulsion jack 24 is received by the existing inner formwork A in the same manner as described above. It cannot be expanded by the presence of 24.

Therefore, first, several propulsion jacks 24 arranged on the upper peripheral side of the tunnel excavator S are contracted,
After setting the several propelling jacks 24 on the lower peripheral side on the front end surface of the existing inner formwork A to prevent slipping,
Only the female mold member 2 on the upper peripheral side of the reduced inner mold A is shown in FIG.
As shown in (4), the rear end face is joined to the front end face of the female mold member 2 on the upper peripheral side of the existing inner mold form A by moving toward the excavation wall surface B side.

This work involves extending the supporting rods 17 and 18 of the telescopic devices D and D by connecting the male frame members 1 and 1 connected to both ends of the female frame member 2 on the upper peripheral side. Done by. That is, when the support rods 17 and 18 of the expansion and contraction devices D and D are extended, the male frame members 1 and 1 connected or gripped at the tips of the support rods 17 and 18 are excavated on the wall surface B in the radial direction of the tunnel. The female mold member 2 is pushed and spread by the connecting rods 3 and 3 which are moved toward and are connected to both ends of the female mold member 2.

When the rear end face of the female form member 2 is joined to the front end face of the female form member 2 on the upper peripheral side of the existing inner form A without steps, both ends of the female form member 2 are inwardly inclined. Outward facing inclined end faces 1a, 1a of the male frame members 1, 1 on both sides of the end faces 2a, 2a.
Are joined together, and the support rods 17 and 18 of the telescopic devices D and D are joined.
After adjusting the amount of expansion and contraction so that there is no step between these joint end faces, the strokes of the support rods 17 and 18 of the expansion and contraction devices D and D are fixed, and between the joint end faces of the male and female form members 1 and 2. After connecting the front end faces of the male and female mold members 1 and 2 of the existing inner formwork A and the rear end faces of these male and female mold members 1 and 2 by bolts, the rod of the propulsion jack 24 is extended to connect them. The male and female form members 1, 2 are received by the front end faces.

Next, after the propulsion jacks 24 arranged on both sides of the tunnel excavator S are contracted, the male form members 1, 1 on both sides are respectively moved in the same manner as described above for the expansion devices D, D. The female frame member 2 and the male frame member 1, which are already expanded to predetermined positions by extending the support rods 17 and 18,
The female form members 2, 2 on the upper sides of both sides which are connected via 1 are expanded, and as shown in FIG.
1 facing outwardly inclined end faces 1a, 1a to the facing inward inclined end face 2
After fixing a and 2a in a state where they are joined to each other without steps and connecting the end faces joined to each other by bolts, the propulsion jack 24 is extended to be received by the front end faces of these male and female formwork members 1 and 2.

In the same manner, after the propelling jack 24 is retreated with respect to the female frame member 2 on the lower peripheral side, the male frame member 1 is pushed forward by the telescopic device D so that the female frame member on the upper peripheral side is pushed. 2 is joined via the male form member 1, and the joining faces thereof and the faces facing the existing inner form A are integrally connected by bolts to assemble the inner form A in an annular shape.

In this way, after the inner formwork A is assembled along the excavated wall surface B of a certain length excavated by the tunnel excavator S, concrete is formed in the ring-shaped space between the excavated wall surface B and the inner formwork A. And the concrete lining C that is continuous with the concrete lining C that was placed first is constructed. In parallel with this concrete lining work, the propulsion jack 24 is extended to the front end surface of the inner form A by a reaction force to extend the tunnel excavator S to excavate the tunnel with a length of one ring of the inner form. I do. During the pouring of concrete, in order to prevent the deformation of the formwork during pouring, the expansion device D
The inner mold form A is held by.

When the pouring of the concrete is completed, the gripping or connection of the expansion / contraction device D with respect to the inner form A is released, and the expansion / contraction device D is moved to the rear end of the beam F by the moving carriage E to complete the hardening of the concrete. The innermost mold A at the rearmost part is reduced in diameter and disassembled by the same work as described above. The reduced inner formwork A is conveyed to the side of the excavation wall surface B behind the tunnel excavator S, assembled in the same manner as above, and this work is repeated to sequentially perform concrete lining on the excavation wall surface B. is there.

10 and 11 show a male mold member 1 and a female mold member 2.
And a mechanism for suppressing the free movement of the male frame member 1 with respect to the female frame member 2 without causing the male frame member 1 to move on a predetermined locus and collide with the female frame member 2. It is configured so as to be joined smoothly and accurately. That is, the central portion of the first link 25 is rotatably attached to the central portion of the inner surface of the female frame member 2 in the plane direction along the frame frame plate 2b, and the second links 26, 26 are provided at both ends of the first link 25. A base end portion of 26 is rotatably pivotally attached, and the tip end portions of the second links 26, 26 connect the male and female form frame members 1, 2 with each other. It is rotatably pivotally attached to the central portion of the connecting rods 27, 27 connected therebetween.

According to the link mechanism thus constructed,
A pair of front and rear connecting rods 3 provided on one end side of the female form member 2
And the pair of front and rear connecting rods 3 provided on the other end side have the same outward rotation angle with respect to the female mold member 2 about the pivotal attachment portion 6b of the bracket 5 protruding from the female mold member 2. , The male frame members 1 and 1 connected to both end sides of the female frame member 2 through the connecting rods 3 and 3 are rotated at the tips of the connecting rods 3 and 3 while their movements in the forward and backward directions and the left and right directions are restricted. The inwardly inclined end surface of the female mold member 2 by moving at the same angle on the motion locus at the same time.
The outwardly inclined end face 1a can be accurately attached to and detached from the 2a.

[0035]

As described above, according to the inner formwork for concrete lining on the tunnel wall surface of the present invention, the male frame member having both end faces formed on the outwardly inclined end faces and the both end faces on the inwardly inclined end face are formed. Since the female mold members formed in the above are alternately arranged and the opposing ends of the adjacent male and female mold members are rotatably connected by the connecting rod, the inner mold has a plurality of male and female molds. Since the frame members are integrated by the connecting rod, the inner frame can be efficiently transported by the movable carriage, and the male frame member is moved in the tunnel radius direction by the expansion / contraction device installed on the movable carriage. Therefore, the expansion device can be extended to expand the diameter between adjacent female form members via the connecting rods so that they can be easily assembled into an annular shape and can be aligned with the previously assembled inner formwork. Easy to do And than, Moreover, those that can be accurately bonded to the inclined end surfaces facing each other while restricting the displacement of the male and female mold members by connecting rods.

Further, when each of the male mold members of the assembled inner mold is moved in the tunnel center direction by the expansion / contraction device,
The outwardly inclined end surface of the male frame member is separated from the inwardly inclined end surface of the female frame member, and the adjacent female frame members are attracted to each other via the connecting rod so that they can be reliably released from the mold. It is possible to form an inner mold having a reduced diameter by joining the opposite ends of the mold members to each other.
The dismantling work can be performed efficiently, and the inner formwork can be smoothly transported to the next concrete lining position with the diameter reduced.

[Brief description of drawings]

FIG. 1 is a simplified front view of an inner formwork,

FIG. 2 is a vertical sectional front view showing a connecting structure of male and female form members;

FIG. 3 is a plan view thereof,

FIG. 4 is a vertical cross-sectional front view of a connecting portion provided with a rotation angle restricting means.

FIG. 5 is a simplified vertical cross-sectional side view of a formwork trolley and a telescopic device arranged behind the tunnel excavator,

FIG. 6 is a longitudinal sectional front view thereof,

FIG. 7 is a simplified front view showing a state where a female frame member on the upper peripheral side is moved in a radial direction,

FIG. 8 is a simplified front view showing a state where the female mold members on both sides are moved in a radial direction,

FIG. 9 is a simplified front view showing a state where the female frame member on the lower peripheral side is moved in the radial direction,

FIG. 10 is a simplified vertical sectional front view showing a free movement restraining link mechanism for male and female form members;

FIG. 11 is a plan view thereof.

[Explanation of symbols]

 1 Male Formwork Member 1a Outward Inclined End Face 2 Female Formwork Member 2a Inwardly Inclined End Face 3 Connecting Rod A Inner Form B Excavation Wall C Concrete Lining D Expansion / contraction E Moving Bogie F Beam S Tunnel Excavator T Tunnel

Claims (2)

[Claims] 1. A moving carriage that moves in the tunnel length direction is arranged on a beam arranged at the center of the tunnel, and is removably supported by a telescopic device installed on the moving carriage and expands and contracts in the radial direction of the tunnel. An inner formwork for concrete lining, wherein a plurality of female form members formed by forming both end faces into inwardly inclined faces inclined in a direction in which the width becomes narrower from the outer peripheral side toward the inner peripheral side, A plurality of male mold members formed by sloping both end faces in a direction of widening from the outer peripheral side to the inner peripheral side and forming outward inclined surfaces that can be joined to the inward inclined surface of the female frame member. The female mold member and the male frame member are alternately arranged in the tunnel circumferential direction, and the opposite ends of the adjacent male and female frame members are rotatably connected by a connecting rod. The male form member in the form member is An inner formwork for concrete lining on a tunnel wall, characterized by being configured to move in the direction. 2. A male / male frame member is provided by disposing a link mechanism in the female frame member, providing a fulcrum of the link mechanism on the female frame member, and pivotally attaching a free end portion of the link mechanism to the connecting rod. The inner formwork for concrete lining of a tunnel wall surface according to claim 1, wherein the inner formwork is configured to be joined without colliding.