JPH0330478Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a joining device for PC boards for tunnel lining.

In recent years, the applicant has adopted a lining construction method for mountain tunnels, etc., in which the load of the ground is supported by shoring, and then a PC lining board is erected between the supports, and this is used as a formwork to connect the ground and PC lining. Formwork and decorative mortar are created by filling the gap between the board and the board with a hardening agent such as backfill concrete, and by taking the load of the ground by combining the hardening agent and the PC lining board. We are currently developing a simple tunnel lining method that does not require any coverings.

By the way, when constructing a tunnel using PC boards, the PC boards are generally assembled sequentially from the left and right side walls of the ground to form an arch shape such as a circular or horseshoe shape. There are difficult issues with the method and how to connect each PC board to each other.
Its assembly is not always easy.

Conventionally, the left and right segments of the preceding ring were connected by a connecting plate with pins inserted through it, and the tips of the pins protruding from this connecting plate were inserted into pipe holes provided in the staggered segments of the following ring. A joining device that connects the two is known.

However, in this device, the connecting plate is only held by a pin at the end and is not fixed, which causes play in the connecting plate, and the segments connected to this plate are also unstablely connected to each other. The ring segment is an unstable connection that causes play by simply inserting the pin into the pipe hole.
In the end, there was a drawback that the bonding state of the entire segments was unstable.

Conventionally, a convex part and a concave part into which the convex part can be fitted are provided on the front and rear surfaces of the segment, and by fitting the two parts, the left and right segments and the segment of the next ring are connected, and the segments of the preceding ring and the next ring are connected by bolts. A joining device for fastening is also known, but the fitting between the concave portion and the convex portion is to the extent that the segments are held during temporary assembly, and the connection and integration is solely by bolt fastening.

This idea was developed to solve the problems in tunnel construction using the tunnel lining method described above, by making it easy to assemble the PC boards, and by firmly and accurately joining each PC board together without the joint members being exposed on the tunnel inner surface. This paper proposes a joint device that can do this.

An example of this invention shown in the drawings will be described below. The PC board is a rectangular board with an arc shape that follows the surrounding surface of the ground, and the PC board 1a for the canopy and the PC board 1b for the side walls are assembled symmetrically. A nut 3 is embedded and fixed in the front surface near the left and right ends so that the bolt 2 can be screwed in from the front, and the head 2' of the bolt 2 is fitted in the rear surface. A fitting hole 4 that can be fitted is provided at a position corresponding to the nut 3.

The head 2' of the bolt 2 has a tapered tip such as a conical shape, and the fitting hole 4 into which the bolt 2 fits is also formed to follow the shape of the head 2'. .

When constructing a tunnel, the PC boards 1a and 1b are assembled into an arch or horseshoe shape via uneven joints 5, 5 on their left and right sides, and
A joint plate 6 is brought into contact between the front ends of the joint of the PC boards 1a and 1b, and the bolts 2 are passed through the left and right through holes 7 provided in the joint plate 6 in correspondence with the nuts 3, and screwed into the nuts 3. The PC boards 1a and 1b are connected to each other at the front via a joint plate 6.

After constructing one span of tunnel lining in this way, do the same in front of the PC boards 1a and 1b.
are assembled, but since the head 2' of the bolt 2 protrudes from the front of each preceding PC board 1a, 1b, insert this head 2' into the fitting hole 4 on the rear face of the following PC board 1a, 1b. By fitting, the front and rear PC boards 1a,
1a and 1b, 1b are accurately positioned and connected to each other, and the adjacent PC boards 1a, 1b are
They are also precisely positioned and connected to each other on the rear surface. Therefore, similarly to the above, the subsequent PC boards 1a, 1
b By connecting each other through the joint plate 6 fastened with bolts 2 at the front, the front, rear, left and right PCs
The plates 1a and 1b are surely integrated with each other.

In addition, as shown in the figure, the joint plate 6 is attached to the PC plates 1a, 1.
If it protrudes from the front of PC board 1a, 1b
A box-shaped recessed portion 8 into which the joint plate 6 fits is provided on the rear surface, but this recess 7 may be provided on the front surface having the nut 3 so that the joint plate 6 is embedded when the bolt 2 is fastened. . It is also possible to further strengthen the connection between the two PC boards 1a and 1a by filling mortar or rod-shaped inserts into the gaps where the concave joints 5 and 5' join each other at the top of the tunnel. Furthermore, the jointing device of this invention can be used at the top of the tunnel.
It may be used only to connect the PC boards 1a and 1a to each other, and the PC boards 1a and 1b may be connected by joints 5 and 5'.

As described above, according to this invention, the left and right PC boards assembled in advance are firmly fixed via the break plates firmly fixed with bolts, and the left and right PC boards assembled subsequently are By fitting the fixed bolts into the fitting holes and fitting the fixed cutout plate into the box-shaped recessed part, the PC board is firmly positioned and connected without wobbling vertically or horizontally.As a result, the PC board It can be independently and firmly integrated without requiring support such as H-shaped steel.

[Brief explanation of the drawing]

Figure 1 is a partial cross-sectional view of the PC board according to this invention.
Figure 2 is a front view showing how the PC boards are connected by the joint plate of this invention, Figure 3 is a partially cutaway front view showing the connection state of the PC boards, and Figure 4 is a front view of the connection state of the PC boards constructed using this invention. It is a front view of a tunnel. 1a, 1b...PC board, 2...bolt, 2'...
Head, 3...nut, 4...fitting hole, 6...joint plate.

Claims (1)

[Scope of utility model registration request] On the front near the left and right ends of the PC board,
A nut that can be screwed in from the front is embedded, and a box-shaped recess is provided on the rear surface near the left and right ends of the PC board.
A fitting hole for fitting the bolt head inside the PC board is provided at a position corresponding to the nut, and the adjacent left and right holes are provided in a row along the surrounding wall of the ground.
A joint plate having a through hole provided at a position corresponding to the nut is brought into contact between the front surfaces of the PC boards, and this joint plate is fastened to the left and right PC boards by a bolt screwed into the nut through the through hole, The heads of the bolts are fitted into the fitting holes on the rear surfaces of subsequent adjacent left and right PC boards assembled in front of the PC board,
A device for joining PC boards for tunnel lining, characterized in that the joint plate is tightly fitted into the recessed portions of the succeeding right and left PC boards that are combined with each other.