JP2520179Y2 - Support leg attachment / detachment structure for secondary lining formwork - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) This invention supports a formwork for a secondary lining in a tunnel, and between the formwork and the inner wall surface of the tunnel which is primary-lined. The present invention relates to an improvement in a structure for attaching and detaching a support leg that holds a predetermined gap.

<< Prior Art >> In tunnel construction, when it is difficult to obtain a sufficient water leakage prevention effect only with the inner wall surface of the tunnel that has been subjected to the primary lining, secondary lining is further performed.

Conventionally, the formwork device used for the secondary lining has a tubular shape for the secondary lining along the inner wall surface 4 of the primary lining part 3 constructed inside the natural ground 1 as shown in FIG. By assembling the formwork 5 into a substantially circular shape and supporting the formwork 5 by the operation arm 13 of the hydraulic device provided in the gate form 11 which is one type of work platform, the formwork 5 and the primary lining surface 4 are separated. There is a device that holds a predetermined gap between them.

Then, the secondary lining concrete 23 is placed in the gap, and after the concrete 23 is completely cured, the formwork 5 is removed to complete the secondary lining.

The problem here is that the formwork 5 must be held while pouring the concrete 23 and while waiting for curing of the concrete 23. It is occupied by the gate type 11 etc., and the setup work for the next secondary lining cannot be performed.

Therefore, the applicant of the present invention has developed a formwork device disclosed in Japanese Patent Publication No. 63-5560.

In this device, a plurality of support legs are protruded from the inside of the form to the outside to support the form with a predetermined gap between it and the primary lining surface. Is
It can be securely held in the tunnel without using a supporting device such as a gate type or a hydraulic device.

In the above configuration, since the support legs are embedded in the concrete solidified after curing the concrete, it is difficult to extract the support legs when disassembling the formwork.

For this purpose, pin holes are formed in the radial direction of the support leg and the intermediate sleeve screwed into the support leg mounting bracket,
Insert the support leg into the intermediate sleeve through the pin, and after concrete curing, pull out this pin to allow the support leg to be pulled out from the intermediate sleeve. Has been done.

<Problems to be solved by the device> However, since the work posture is upward, especially on the ceiling side, the alignment of the pin hole position when inserting the pin is complicated, and the pin is pulled out when the support leg is removed. The work is troublesome and difficult.

This invention solves the above problems, and by simplifying the work of attaching and detaching the support legs to and from the intermediate sleeve,
It is another object of the present invention to provide a support leg attachment / detachment structure for a secondary lining formwork with improved work efficiency.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the present invention relates to a tubular mold for disassembling secondary lining which is assembled in a substantially circular shape on the inner wall surface of the tunnel which is primary lining, and the mold. A plurality of support legs that radially project from the inside to the outside and abut the primary lining surface, and a bracket that projects inside the formwork and detachably holds the support legs. In a secondary lining formwork in which a predetermined gap is held between the formwork and the primary lining surface by legs, and the formwork is supported only by the support legs, the support legs are screwed to the bracket. By inserting a pair of wedges that engage in a tapered shape into rectangular wedge holes that are inserted in the intermediate sleeve to be attached and that are bored in the radial direction of the support leg and the intermediate sleeve, the intermediate sleeve is attached to and detached from the intermediate sleeve. Possible to lock and fix It is what is done.

<< Operation >> According to the above configuration, even if the wedge holes of the support leg are displaced from the wedge holes of the intermediate sleeve, by driving one wedge and then the other wedge from the other side, , Both of which engage in a tapered shape to correct the correct hole position and fix the support leg at a predetermined position of the intermediate sleeve.

When removing the support legs, both wedges can be easily removed by tapping one of the wedges in the opposite direction to the engaging direction, and the support legs can be pulled out.

<< Embodiment >> Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In addition, the same or corresponding portions in the drawings are denoted by the same reference numerals.

1 to 4 show an embodiment of a frame device for secondary lining in a tunnel according to the present invention.

The formwork device shown in the figure has a tubular formwork 5 for secondary lining, which is assembled in a substantially circular shape along the inner wall surface 4 of the tunnel 2 which has been primaryly covered, and two radial lines from the inside to the outside of the formwork 5. A plurality of support legs 12 protruding to abut on the primary sub-rear surface are provided in a removable manner, and the support legs 2 hold a predetermined gap d between the mold 5 and the primary lining surface.

The form 5 is formed by assembling a crown form 6 forming a ceiling surface, a side form 7 forming a side surface and an invert form 8 forming a floor surface by a hinge 9 and a connecting portion 10 such as a bolt. Gate type 11 is used only when disassembled.

The support leg 12 is a bracket fixed by welding or the like to a part of a frame 5a vertically and horizontally arranged inside the formwork 5.
It is removably attached to 16 via an intermediate sleeve 17.

The intermediate sleeve 17 has a cylindrical shape, and a threaded portion is provided on the outer periphery thereof.
17a is formed, and the screw portion 17a is screwed and fixed in the screw hole 16a formed on the bracket 16 side. Further, the intermediate sleeve 17 is formed with a wedge hole 19 having a rectangular cross section and penetrating in the radial direction thereof.

The support leg 12 has a cone-shaped distal end portion 14 and has a base end portion.
15 is a straight rod shape, intermediate sleeve
It is inserted into the inside of the mold 17, radially projects from the inside of the mold 5 toward the outside, and abuts on the receiving portion 4a fixed in advance on the inner wall surface 4 of the primary lining portion 3.

A through hole 18 of the jig device is formed in the base end side 15 of the support leg 12 in the radial direction, and a hole is also formed in the same radial direction in the vicinity of the coaxial hole, and is the same as the intermediate sleeve 17. A wedge hole 20 having a rectangular cross section with an opening cross sectional area is formed.

In the above structure, in order to fix the support leg 12 to the intermediate sleeve 17, the support leg 12 is inserted into the intermediate sleeve 17 and penetrated to the outside of the form 5, and then the wedge holes 1 formed in both of them.
9 and 20 are roughly aligned, and a pair of wedges 21 and 22 are driven so that their tapered surfaces are aligned.

In this case, when one wedge 21 is driven in, the support leg 12 is supported by the intermediate sleeve 17.

Next, drive the wedge 22 on the other side from the opposite direction,
Wedge hole 1 due to the tapered engagement of both wedges 21 and 22
The displacement of 9, 20 is corrected and the supporting leg 12 is fixed to the correct position of the intermediate sleeve 17, and the tip portion 14 of the supporting leg 12 projects outside the mold 5 with the set projecting length d. .

When adjusting the protrusion length d, fine adjustment is continuously performed by rotating the intermediate sleeve 17.

In this way, each of the plurality of support legs 12 projects outside the mold 5 and defines a gap from the primary lining surface of the mold 5.

After the formwork 5 is assembled inside the primary lining surface as described above and the position thereof is determined by the support legs 12,
It can be retained without the gate type 11.

Therefore, after the position of the formwork 5 is determined, a necessary work space can be secured inside the formwork 5, and then the secondary lining concrete 23 can be placed for curing.

On the other hand, the gate mold 11 removed from the inside of the formwork 5 is used to perform the work of assembling the formwork 5 in the adjacent section by moving it forward or backward, and the formwork in which the curing of the concrete 23 has already been completed. It can be used for the removal work of item 5.

As a result, further work can be performed while the concrete 23 is being cast and before the curing of the concrete 23 is completed.

Next, when the concrete 23 is completely cured and the form 5 is removed, the support legs 12 are first pulled out. In this case, one of the wedges 21 and 22 is locked in a tapered shape. If you hit it with a hammer in the opposite direction, the engagement will be released easily.

After that, both wedges 21 and 22 can be easily pulled out manually from the wedge holes 19 and 20.

In particular, in the case of upper work, only one of them has to be tapped, so the tapping work can be performed by selecting a convenient scaffold position.

After that, a jig such as a burl is wound around the through hole 18 and the supporting leg is
When the 12 is pulled out, the support leg 12 can be pulled out from the poured concrete 23.

It should be noted that in order to facilitate pulling out of the support leg 12, grease or other sliding member may be applied to the outer periphery of the support leg 12 in advance.

In addition, the support leg 12 having the above configuration and the structure for attaching and detaching it are
In particular, it is a support leg with a constant protruding length on the upper side, and it is applied to the place of the crown form 6 where the installation and removal work is in an upward posture, and the other places are the protruding length shown in Japanese Patent Publication No. 63-5560. A detachable structure with adjustable support legs and pins can also be adopted.

<Effect of Device> As described in detail with reference to the embodiments above, in the support leg attachment / detachment structure in the secondary lining formwork according to the present invention, the support leg installation / removal at the time of formwork assembly and disassembly. The work can be performed quickly, and the efficiency of the work performed especially in the upward posture at the time of assembling and disassembling the mold can be further improved.

[Brief description of drawings]

FIG. 1 is a front sectional view of a formwork device for secondary lining in a tunnel according to the present invention, FIG. 2 is a front sectional view showing a state in which a gate mold is removed from the formwork device, and FIG. FIG. 4 and FIG. 4 are exploded perspective views of essential parts, and FIG. 5 is a front sectional view of a conventional frame device for secondary lining in a tunnel. 2 …… Tunnel 14 …… Inner wall surface 5 …… Formwork 11 …… Gate type 12 …… Support legs 14 …… Tip part 15 …… Base part 16 …… Bracket 17 …… Intermediate sleeve 19, 20 …… Wedge Hole 21,22 …… Wedge 23 …… Concrete for secondary lining

Claims (1)

(57) [Scope of utility model registration request] 1. A tubular formwork for disassembling a secondary lining, which is assembled in a substantially circular shape on the inner wall surface of a primary lining tunnel, and radially projects from the inside to the outside of the formwork to abut the primary lining surface. A plurality of support legs and a bracket projecting inward of the formwork and detachably holding the support legs are provided, and the support legs provide a predetermined space between the formwork and the primary lining surface. In a secondary lining formwork that holds a gap and supports the formwork only by the support legs: the support legs are inserted into an intermediate sleeve screwed to the bracket, and the support legs and the A secondary cover characterized by being removably locked and fixed to the intermediate sleeve by driving a pair of wedges that taperly engage into a rectangular wedge hole that is bored in the radial direction of the intermediate sleeve. Of support legs in engineering formwork Detachable structure.