JP7528656B2 - End formwork fixing device - Google Patents

Description

The present invention relates to a gable formwork fixing device for a concrete lining center.

When constructing mountain tunnel lining concrete, a semi-cylindrical movable formwork called a "center" is used to pour concrete into the inner surface of the tunnel (see, for example, Patent Documents 1 and 2). When pouring the concrete, a wooden board with a spoke of about 20 cm called a "gable formwork" is used as a stop formwork at the end of the "center," which forms the construction joint, and is installed to close the opening between the ground and the "center."

Patent Document 1 proposes a technique in which an end formwork shaped according to the thickness of the lining concrete is supported by a rod-shaped support member fixed to the end face of the center tunnel. In addition, Patent Document 2 proposes a technique in which the end formwork that covers the end side of the center tunnel for tunnel lining is divided in the circumferential direction of the center tunnel, and hinged to the inner and outer sides of the center tunnel so that it can swing freely.

JP 2001-248397 A JP 2011-184869 A

However, supporting the gable formwork with rod-shaped support members or hinge connections did not provide sufficient strength against the concrete pouring pressure, so in practice, through members using thickened corners or the like were placed around the periphery of the lining concrete and secured in place with beams for fixing the gable formwork (pipe supports or thickened corners).

The through bars and gable formwork fixing beams are firmly installed each time the lining concrete is poured to prevent the gable formwork from moving or coming off, and are removed after pouring. Because the through bars are not fixed to the gable formwork with nails or other fasteners, the installation and removal of the through bars and gable formwork fixing beams is carried out on the center scaffolding, but in some places, such as on the side walls, the work requires workers to lean over the scaffolding. In addition, the installation interval for the gable formwork fixing beams depends largely on the worker's intuition (level of skill), and if the interval is insufficient, the gable formwork will come off or move during concrete pouring, causing problems. Furthermore, since the gable formwork, which has a circumference of about 20 m, must be fixed each time concrete is poured, it takes a lot of time and effort. For these reasons, the installation and removal of the through bars and gable formwork fixing beams is dangerous, involves falling, and is a complicated task that requires skill.

The present invention aims to provide a gable formwork fixing device that allows for easy installation and removal of through members and gable formwork fixing beams that are abutted against the gable formwork.

The gable formwork fixing device of the present invention is a gable formwork fixing device that fixes multiple gable formworks arranged side by side on the gable face in the pouring space between the inner surface of a tunnel and the formwork of a center tunnel, and is characterized in that it is equipped with a through member that abuts the multiple gable formworks, and a gable formwork fixing beam whose open end supports the through member and whose base end is supported by a burr-receiving steel material that protrudes from the gable face side of the center tunnel, and the gable formwork fixing beam is equipped with an extension and contraction mechanism .
Furthermore, in the end form fixing device of the present invention, the through member may be supported by being stretched across two or more of the end form fixing beams.
Furthermore, in the gable form fixing device of the present invention, the gable form fixing burrs may be supported by the through member and the burr receiving steel member, respectively, so as to be rotatable in the normal direction to the perimeter of the form.
Furthermore, in the end form fixing device of the present invention, the end form fixing burrs may be supported by the burr receiving steel material on the inner peripheral side relative to the peripheral surface of the form.
Furthermore, the gable formwork fixing device of the present invention may be provided with a height adjustment member equipped with an expansion and contraction mechanism interposed between the open end of the gable formwork fixing beam and a position on the burr-receiving steel material closer to the gable face than the base end of the gable formwork fixing beam.

According to the present invention, the through member and the gable form fixing beam are supported by the center as a single unit. After the gable form is installed, the through member and the gable form fixing beam can be easily installed on the gable form by extending the telescopic mechanism. After pouring is completed, the through member and the gable form fixing beam can be easily removed from the gable form by contracting the telescopic mechanism.

A diagram showing the configuration of a center in which the end formwork fixing device of the present invention is installed. FIG. 2 is a view of the center shown in FIG. 1 as seen from the face side. FIG. 2 is a diagram showing the configuration of a gable formwork fixing device according to the present invention. FIG. 4 is a side view showing the configuration of the end formwork fixing beam shown in FIG. 3 . FIG. 4 is a side view showing the gable formwork fixing beam shown in FIG. 3 in a folded state.

Next, a form for implementing the present invention (hereinafter simply referred to as "embodiment") will be specifically described with reference to the drawings.

Referring to FIG. 1, the end form fixing device 1 of this embodiment is installed on a center 2 having an arch-shaped form 21 that follows the inner periphery of a tunnel that is primarily supported by spraying concrete, etc., and supports the end form that closes the end face of the casting space for the lining concrete (hereinafter simply referred to as casting space C) that is formed between the inner periphery of the tunnel and the center 2 (form 21).

The center tunnels 2 can run on rails 3 that are laid along the tunnel axis (the direction in which the lining concrete is constructed). When the lining concrete is constructed from the tunnel mouth toward the face, multiple end formwork fixing devices 1 are installed on the face side of the center tunnel 2 along the perimeter of the formwork 21.

The formwork 21 is a steel member with a cross-sectional shape in the tunnel width direction that is roughly semicircular so as to fit along the inner circumferential surface of the tunnel. As shown in FIG. 2, the formwork 21 is supported by a movable platform 23 via multiple jacks 22. The space between the formwork 21 and the inner circumferential surface of the tunnel becomes the casting space C.

The mobile platform 23 is made of H-shaped steel, channel steel, etc., and is equipped with multiple portal frames 24 arranged at the front and rear, and multiple vertical beam members (not shown) that connect the multiple portal frames 24. The lower end of the portal frames 24 is equipped with wheels 25 for running on the rails 3. The spatial cross section inside the portal frames 24 functions as a tunnel for transporting waste, etc.

The center 2 (formwork 21) has a number of first burr support steel members 26 that protrude from the end face side toward the face at predetermined intervals along the perimeter of the formwork 21, and end formwork fixing devices 1 are installed between adjacent first burr support steel members 26.

Referring to Figs. 3 and 4, the gable form fixing device 1 is a device that supports the concrete pouring pressure by contacting multiple gable formworks 4 arranged side by side on the gable surface of the casting space C, and is composed of a through member 11, two first gable formwork fixing beams 12, a second gable formwork fixing beam 13, and a height adjustment member 14. The reference numeral 27 shown in Fig. 3 is an angle member that is spaced apart from the formwork gable surface 21a that is extended from the tunnel mouth end of the formwork 21 toward the inner circumference. The angle member 27 functions as a fall prevention member that prevents the gable formwork 4 from falling off, and also functions as a fixing member that fixes the gable formwork 4 by driving a camber (wedge) 5 between the angle member 27 and the gable formwork 4. Also, in Fig. 4, (a) is a side view of the first gable formwork fixing beam 12 and the height adjustment member 14, and (b) is a side view of the second gable formwork fixing beam 13.

The through member 11 is made of rod-shaped temporary materials such as square pipes, thick-end squares, and H-shaped steel, and functions as an abutment part that abuts against multiple end forms 4 arranged side by side on the end face of the casting space C. A pair of brackets 31 is attached near both ends of the through member 11, and one end of the first end form fixing beam 12 is rotatably supported by each bracket 31 via a connecting pin 41 parallel to the through member 11. In addition, a bracket 32 is attached near the center of the through member 11, and one end of the second end form fixing beam 13 is rotatably supported by the bracket 32 via a connecting pin 42 parallel to the through member 11.

Second burr support steel materials 26a, which are shaped to follow the perimeter of the formwork 21, are fixed to the multiple first burr support steel materials 26, with a gap between them and the end face of the casting space C. Three brackets 33 for supporting the two first end formwork fixing burrs 12 and the second end formwork fixing burrs 13 are attached to the second burr support steel materials 26a at the same intervals as the pair of brackets 31 and 32 of the through member 11. The other ends of the first end formwork fixing burrs 12 and the second end formwork fixing burrs 13 are rotatably supported by the three brackets 33 via connecting pins 43 parallel to the through member 11. As a result, the first end formwork fixing burr 12 and the second end formwork fixing burr 13 are installed so that they can rotate in the normal direction to the circumference of the formwork 21, with the other end supported by the second burr support steel material 26a as the base end and one end supported by the through material 11 as the open end.

The first end form fixing burrs 12 and the second end form fixing burrs 13 are rod-shaped members equipped with an expansion mechanism for adjusting the length, and for example, pipe supports, which are temporary materials, can be used. As a result, the length can be adjusted by the expansion mechanism of the first end form fixing burrs 12 and the second end form fixing burrs 13, and the through member 11 can be abutted against multiple end formworks 4 arranged side by side on the end surface of the casting space C, so that the concrete pouring pressure can be supported by the second burr support steel material 26a (first burr support steel material 26). After pouring the concrete, the end formworks 4 can be easily removed by contracting (loosening) the expansion mechanism of the first end form fixing burrs 12 and the second end form fixing burrs 13.

In addition, a hydraulic or electrically operated cylinder may be used as the extension mechanism for the first end form fixing beam 12 and the second end form fixing beam 13.

The ends of the first end form fixing beam 12 and the second end form fixing beam 13 are rotatably supported by the through material 11 and the second beam support steel material 26a, respectively, so they can accommodate a variety of winding thicknesses. The length of the through material 11 and the number of the first end form fixing beam 12 and the second end form fixing beam 13 are set appropriately taking into account the pouring pressure of the concrete, and are equipped in advance on the center 2.

A bracket 34 is attached near the open end of the first end formwork fixing beam 12, and one end of the height adjustment member 14 is rotatably supported on the bracket 34 via a connecting pin 44 that is parallel to the through member 11.

The mounting steel 26b, to which a bracket 35 for supporting the other end of the height adjustment member 14 is attached, is fixed to the first burr support steel 26, closer to the formwork end face 21a side than the second burr support steel 26a. The other end of the height adjustment member 14 is rotatably supported by the bracket 35 via a connecting pin 45 that is parallel to the through member 11. The mounting steel 26b also has a bracket 35 attached for the end formwork fixing device 1 that is installed adjacently.

The height adjustment member 14 is a rod-shaped member having an extension mechanism, and for example, a pipe support can be used. The extension mechanism of the height adjustment member 14 may be hydraulically or electrically extendable. The height adjustment member 14 is interposed between the vicinity of the open end of the first gable formwork fixing beam 12 and a position on the formwork gable face 21a side of the base end supported by the second burr support steel material 26a of the first burr support steel material 26. As a result, by extending and retracting the height adjustment member 14, the height of the open end of the first gable formwork fixing beam 12 on which the through member 11 is supported can be easily adjusted, and the position where the through member 11 abuts against the gable formwork 4 can be easily adjusted. In addition, the height adjustment member 14 also has the function of reinforcing the support force of the first gable formwork fixing beam 12 against the concrete pouring pressure.

In addition, by using the height adjustment member 14 to adjust the through material 11 (the free end of the first gable formwork fixing beam 12) to a height that does not interfere with the inner periphery of the tunnel, it can pass through the excavation cross section in its current state except in the reinforced bar section where the rebar has already been assembled. In the reinforced bar section, the height adjustment member 14 can be shortened and tilted down to allow passage through the hollow side inside the rebar.

The first burr support steel 26 that supports the first gable form fixing burr 12 is positioned on the inner side of the peripheral surface of the formwork 21. Therefore, by removing the connecting pin 45 and eliminating the support of the height adjustment member 14 by the bracket 35 (first burr support steel 26), the gable form fixing device 1 can be folded on the inner side of the peripheral surface of the formwork 21 as shown in FIG. 5. This makes it possible to avoid the hollow side of the reinforcing bar. The same effect can be obtained by removing the connecting pin 44 and eliminating the support of the height adjustment member 14 by the bracket 34 (first gable form fixing burr 12).

As described above, this embodiment is a gable formwork fixing device 1 that supports the pouring pressure of concrete by abutting a through member 11 against multiple gable formworks 4 arranged side by side on the gable face in the pouring space C between the inner surface of the tunnel and the formwork 21 of the center telescopic 2, and is equipped with a first gable formwork fixing beam 12 whose open end is supported by the through member 11 and whose base end is supported by a first beam support steel material 26 protruding from the gable face 21a side of the formwork of the center telescopic 2, and the first gable formwork fixing beam 12 is equipped with an extension mechanism.
With this configuration, the through member 11 and the first gable form fixing beam 12 are supported by the center 2 as a unit, so that after the gable form 4 is installed, the through member 11 and the first gable form fixing beam 12 can be easily installed on the gable form 4 by extending the telescopic mechanism. In other words, since the length of the first gable form fixing beam 12 only needs to be finely adjusted, the work can be easily performed by one person, and the problem of the gable form 4 coming off or moving can be prevented regardless of who is performing the work. After the concrete pouring is completed, the through member 11 and the first gable form fixing beam 12 can be easily removed from the gable form 4 by contracting the telescopic mechanism. As a result, the through member 11 and the first gable form fixing beam 12 do not need to be installed and removed from the center 2 every time concrete is poured, and the fixing work of the gable form 4 can be performed quickly and easily.

Furthermore, in this embodiment, the through material 11 is supported by being stretched across two or more first end form fixing beams 12 (second end form fixing beams 13).
This configuration allows the through material 11 to be stably supported.

Furthermore, in this embodiment, the first end form fixing burr 12 is supported by the through material 11 and the first burr receiving steel material 26 so as to be rotatable in the normal direction to the perimeter of the form 21 .
With this configuration, the circumferential installation position can be easily adjusted according to the winding thickness.

Furthermore, in this embodiment, the first end form fixing burr 12 is supported by a first burr support steel material 26 on the inner circumferential side relative to the peripheral surface of the form 21 .
With this configuration, the end formwork fixing device 1 can be folded inward from the peripheral surface of the formwork 21, and can pass through the hollow side inside the assembled reinforcing bar.

Furthermore, in this embodiment, a height adjustment member 14 equipped with an expansion and contraction mechanism is provided, which is interposed between the open end of the first end formwork fixing beam 12 and a position on the first beam support steel 26 that is closer to the formwork end face 21a than the base end of the first end formwork fixing beam 12.
With this configuration, by expanding or contracting the height adjustment member 14, the height of the open end of the first gable form fixing beam 12 on which the through member 11 is supported can be easily adjusted, and the position at which the through member 11 abuts against the gable form 4 can be easily adjusted. In addition, the support force of the first gable form fixing beam 12 against the pouring pressure of concrete can be reinforced.

The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in terms of the combination of each component, and that such modifications are also within the scope of the present invention.

1 Gable form fixing device 2 Center 3 Rail 4 Gable form 5 Camber 11 Through member 12 First gable form fixing burr 13 Second gable form fixing burr 14 Height adjustment member 21 Form 21a Form end surface 22 Jack 23 Mobile stand 24 Gate frame 25 Wheel 26 First burr support steel material 26a Second burr support steel material 26b Mounting steel material 27 Angle material 31, 32, 33, 34, 35 Bracket 41, 42, 43, 44, 45 Connecting pin C Casting space

Claims (5)

A gable form fixing device that fixes a plurality of gable formworks arranged side by side on a gable surface in a casting space between an inner circumferential surface of a tunnel and a center formwork,
A through member abutting against a plurality of the gable forms;
The through member is supported at an open end , and a burr for fixing the end formwork is provided, the burr being supported at a base end by a burr receiving steel material protruding from the end face side of the center,
The end formwork fixing device is characterized in that the end formwork fixing beam is equipped with an extension mechanism. The end formwork fixing device according to claim 1, characterized in that the through member is supported by being stretched across two or more of the end formwork fixing beams. The end form fixing device according to claim 1 or 2, characterized in that the end form fixing burrs are supported by the through material and the burr receiving steel material so as to be rotatable in the normal direction to the perimeter of the form. The end formwork fixing device according to claim 3, characterized in that the end formwork fixing burrs are supported by the burr support steel material on the inner side of the peripheral surface of the formwork. The gable formwork fixing device according to any one of claims 1 to 4, characterized in that it is provided with a height adjustment member with an expansion mechanism interposed between the open end of the gable formwork fixing beam and a position on the gable face side of the base end of the gable formwork fixing beam on the burr receiving steel material.

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