JPH09268890A - Segment for tunnel lining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the execution efficiency in the tunnel lining by a flat plate segment in which the prestress is introduced. SOLUTION: A flat plate segment 10 is curved in an arc-shape, and contains a concrete body 16 having a plurality of connection bolt receiving spaces 30 and inner circumferential surfaces 32 on which the connection bolt receiving spaces are released. A plurality of joining plates 20, 24 are embedded in a circumferential end part 18 and a width direction end part 22 of the body. Each joining plate has a joining bolt hole 38 to be communicated with each connection bolt receiving space 30. A PC steel 26 which is extended at least in the circumferential direction or the width direction, and fixed to the joining plates opposite to each other and tensioned is arranged in the body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat plate segment for tunnel lining.

[0002]

2. Description of the Related Art Heretofore, there has been proposed a flat plate-shaped segment in which a prestress is introduced into a concrete body which is curved in an arc shape. The pre-stressed segment can reduce the amount of bar arrangement compared to the non-introduced segment, and is advantageous in reducing the segment thickness (height) dimension and segment weight. is there.

An example of a segment to which prestress is introduced is disclosed in Japanese Utility Model Publication No. 61-39031, in which a sheath extending in the circumferential direction and a PC passed through the sheath are embedded in the body of the segment. Each end of the PC steel material terminates in a recess provided in the circumferential end of the body.

The introduction of prestress is carried out by assembling these segments into a ring along the wall surface of the tunnel, and then terminating the ends of the PC steel products terminating in the recesses of both segments circumferentially adjacent to each other on the other side. By pulling and connecting towards. Since both PC steel materials are in a tensioned state and are connected to each other, the two adjacent segments exert a pressing force toward each other at their abutting end faces (circumferential end faces). As a result, prestress is introduced in each segment.

[Problems to be Solved by the Invention]

By the way, to introduce the prestress,
In the recess defined by both adjacent segments, the P
It is necessary to arrange a means for tensioning the C steel material and a connecting means for connecting both PC steel materials to each other, and further it is necessary to activate the tensioning means and then remove the tensioning means. And However, these operations require a lot of labor and time, which reduces the construction efficiency of the tunnel lining.

An object of the present invention is to improve the construction efficiency of the tunnel lining by the flat plate type segment to which the prestress is introduced. Another object of the present invention is to provide a prestressed flat plate-shaped segment that enhances the construction efficiency of the tunnel lining.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a concrete-shaped main body which is a flat plate segment curved in an arc shape and has a plurality of joint bolt receiving spaces and an inner peripheral surface released by the joint bolt receiving spaces. A plurality of joint plates each having a joint bolt hole embedded in each of a circumferential end portion and a widthwise end portion of the main body and communicating with each joint bolt receiving space, and at least the inside of the main body in the circumferential direction and the width direction. PC steel which extends to one side and is fixed and tensioned to both joint plates facing each other.

The PC steel material is, for example, a thread-bar reinforcement, and an end portion of the thread-bar reinforcement is screwed into a cone that is received in a hole formed in the joint plate and is wedged. Furthermore, a plate member embedded in the circumferential end portion of the main body and located on the outer peripheral surface side of the main body with respect to the joint plate, and extending in the circumferential direction inside the main body, and fixed to both joint plates facing each other, and Tensioned PC steel can be provided.

[0009]

According to the present invention, since prestress is introduced into each segment in advance by the PC steel material in a tensioned state, the prestress is introduced after assembling a plurality of segments as in the conventional case. No need for Therefore, it is possible to eliminate the labor and time required for preparing the tensioning means for the PC steel material during the lining, operating the tensioning means, removing the tensioning means, and the like. Further, since both ends of the PC steel material are fixed to both joint plates facing each other, the interconnection of the segments assembled in the circumferential direction or the axial direction of the tunnel is bolted.
Doing with nuts, i.e. inserting bolts from the splice bolt receiving space of one segment into the splice bolt holes of both joint plates and then screwing the nut into the splice bolt in the splice bolt receiving space of the other segment. It can be done by According to this, the interconnection of the segments can be performed easily and in a short time like the interconnection of the normal segments in which the prestress is not introduced. From these things, the construction efficiency of the tunnel lining can be improved by using the segment of the present invention.

When both joint plates are tightened with the bolt and nut, the bolt is slightly stretched and the bolt is placed in a tensioned state. Therefore, the two adjacent segments are kept in close contact with each other.

It is possible to select a threaded rebar having the above-mentioned PC steel material having a node extending spirally on the peripheral surface. The end of the threaded joint bar is passed through a hole provided in the joint plate, a cone is screwed into the end, and the cone is wedged in the hole of the joint plate, whereby the joint is formed. It can be fixed on the board and maintain tension.

Further, in addition to the joint plate and the PC steel material fixed to the joint plate, a plate member similar to these and a PC member
By further disposing the member on the outer peripheral surface side of the segment main body, prestress can be exerted on the inner peripheral side and the central portion of the segment as well as on the outer peripheral side.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2 and 3 show examples 10, 12, 1 of a flat plate segment according to the present invention, respectively.
4 is shown.

Each of the segments 10 (FIG. 1), 12 (FIG. 2), 14 (FIG. 3) is provided with a main body 16 made of concrete which is curved in an arc shape and a plurality of ends 18 in the circumferential direction of the main body 16. (Two in the illustrated example) joint plates 20 and a plurality of (three in the illustrated example) joint plates 24 provided at each end portion 22 in the width direction of the main body 16, and a plurality embedded in the main body 16. PC steel materials 26 (FIG. 1) and 28 (FIG. 2). However, although a plurality of PC steel materials 26 are arranged in the segment 14 shown in FIG. 3 as in the segment 10 shown in FIG. 1, the PC steel material 26 is not shown in order to avoid complexity of the drawing.

The segment body 16 is provided with a plurality, more specifically, the same number of joint bolt receiving spaces 30 as the number of the joint plates 20 and 24. Each joint bolt receiving space 30 is open to the inner peripheral surface 32 of the main body 16, and each joint plate 2
A part thereof is defined by 0 and 24. The plurality of joint bolt receiving spaces are paired and face each other in the circumferential direction and the width direction of the body 16. These joint bolt receiving spaces 30 are used to connect a pair of segments, which are arranged along the wall surface of the tunnel and are adjacent to each other in the circumferential direction and the axial direction of the tunnel, to each other, during the lining of the tunnel. The quantity of the joint bolt receiving space 30 and therefore the joint plates 20 and 24 can be set arbitrarily.

Each of the joint plates 20 and 24 made of steel plates is the main body 1
6 is embedded in each end of the main body 16, and a part thereof defines a part of the end surface 34 in the circumferential direction of the body 16 and a part of the inner peripheral surface 32, and a part of the end surface 36 in the width direction and the inner circumference A portion of surface 32 is defined. According to this, when the plurality of segments 10 are assembled to form the lining, the joint plates 20 and the joint plates 24 contact each other. Alternatively, instead of the illustrated example, at least one of the joint plates 20, 24 can be embedded in the body 16 so as to define the bottom surface of a recess (not shown) that opens into the end surfaces 34, 36. According to this, when the plurality of segments 10 are assembled, the space between the joint plates 20 or between the joint plates 24 is increased.
A gap formed by the two recesses is formed between the joint plates, and the joint plates face each other without contacting each other.

Each joint plate 20, 24 has a joint bolt hole 38, and each bolt hole 38 communicates with the corresponding joint bolt receiving space 30. These bolt holes 38 are also
In addition, the circumferential direction and the width direction of the main body 16 are paired and face each other.

Thus, when assembling a plurality of said segments for tunnel lining, the joint bolt holes 38 of both adjacent segments are aligned with each other. The segments may be connected by passing a joint bolt (not shown) through the aligned bolt holes 38 and screwing a nut (not shown) on the joint bolt. Insertion of the joint bolt into the bolt hole 38 and screwing of the nut can be performed by inserting the joint bolt into the joint bolt receiving space 30 of both segments from the inner space of the tunnel.

A plurality of PC steel materials 26 are arranged at intervals from the inner peripheral surface 32 of the main body 16 toward the outer peripheral surface 40 thereof,
It extends in an arc shape along the inner and outer peripheral surfaces 32, 40. A plurality of (four in the illustrated example) PC steel materials 26 are fixed to both joint plates 20 whose both end portions face each other,
I'm nervous. Prestress is introduced in the circumferential direction of the body 16 and thus the segments 10, 14 via the two pairs of joint plates 20 by means of the PC steel 26 in tension.

The plurality of PC steel materials 28 are also arranged at intervals from the inner peripheral surface 32 of the main body 16 toward the outer peripheral surface 40 thereof and extend linearly. Multiple (4 in the example shown)
The both ends of the PC steel material 28 are fixed to both joint plates 24 facing each other and are tensioned. Three pairs of joint plates 24 by PC steel material 28 placed in a tension state
A prestress is introduced into the main body 16 and thus the segments 10 and 14 in the width direction thereof.

The PC steel material can be arranged in both the circumferential direction and the width direction instead of the illustrated embodiment in which the PC steel material is arranged only in the circumferential direction or the width direction. In this case, needless to say, the PC members extending in the circumferential direction and the width direction are arranged so as to cross each other.

Further, as shown in FIG. 3, a plurality of PC steel materials 42 can be additionally arranged on the outer peripheral surface 40 side of the segment main body 16. Thereby, the distribution of the prestress introduced into the main body 16 can be adjusted. The ends of these PC steel materials 42 are fixed to a pair of steel plate members 44 embedded in the respective circumferential ends 18 of the main body 16.

Each plate member 44 is connected to the outer peripheral surface 4 from the joint plate 20.
They are arranged at intervals toward 0, and a part thereof defines a part of each circumferential end face 34. Instead of providing each plate member 44, one having a longer length dimension (dimension in the height direction of the segment) is adopted as each joint plate 20, and each such joint plate 20 is made of each PC steel material 42. The ends may be fixed. The quantity, diameter, etc. of the PC steel materials 26, 28, 42 are selected in consideration of the size of the segment, the design strength to be given to the segment, and the like. Also,
The PC steel members 26, 28, 42 may be arranged so as to extend through the joint bolt receiving space 30, that is, exposed to the space 30, but preferably the space 30.
Place it so that it is not exposed.

The fixing of the end portions of the PC steel materials 26, 28, 42 to the joint plates 20, 24 and the plate member 44 can be performed, for example, through the structure shown in FIG. In this example, the PC steel material is a threaded joint bar having a joint 46 extending spirally, and each joint plate 20, 24 and each plate member 44 are provided with a hole 48 for allowing the threaded joint bar to be inserted. . The hole 48 has a wall surface formed of a conical surface, and is tapered toward the main body 16.

Inside the hole 48, a cone 50 having a conical surface in contact with the wall surface of the hole is arranged. The cone 50 has one end having a diameter that is larger than the diameter of the body-side opening of the hole 48 and does not slip out of the body-side opening of the hole 48 due to the wedge action.

Further, the cone 50 is provided with a hole extending coaxially with the hole 48, and the wall surface of the hole is provided with a groove 52. The ends of the threaded bar reinforcements are received in the holes in the cone 50 and their nodes 46 engage the spiral groove 52 in the cone 50.

The introduction of prestress to the segment can be performed, for example, as follows.
First, prior to placing concrete on a formwork (not shown), a pair of joint plates 20 and 24 facing each other or a pair of plate members 4 facing each other arranged on the formwork.
A sheath (not shown) communicating with the hole 48 of No. 4 is arranged in the formwork, and after the concrete is hardened, for example, the threaded bar reinforcing bar is passed through the sheath and the opposite holes 48.
Next, both ends of the threaded joint reinforcing bar are screwed into both cones 50, and one cone 50 into which one end of the threaded joint reinforcing bar is screwed is housed in one hole 48. Pull the ends with suitable pulling means. Then, the other cone 50 is rotated around the other end of the threaded joint bar and advanced until it locks on the wall surface of the other hole 48. Then, the pulling of the thread-bar reinforcement is stopped. The screw joint reinforcing bar has both holes 48.
A tensioned state, that is, a tensioned state is maintained by the wedge action between the and the cones 50. As a result, the main body 16 is compressed in at least one of the circumferential direction and the width direction thereof via the joint plates 20 and 24 or the plate member 44, whereby prestress is introduced into the segment. Both ends of the threaded link reinforcing bar are prevented from protruding outside from the hole 48 by cutting or the like.

Segments 10, 12, 14 according to the invention
Since the prestress is introduced during its manufacturing, the segments can be assembled at the site of tunnel lining in the same way as the so-called RC segment in which the prestress is not introduced. Can be connected. Therefore, compared to the conventional one that introduces prestress to each segment after assembling the segments, the lining work can be performed easily and in a short time,
Therefore, it can be performed efficiently.

Further, when the joint plates of the plurality of segments assembled in the ring facing each other are tightened with the joint bolt and the nut, the joint bolt is slightly stretched within its elastic range and is in a tension state. Both segments are subjected to a tensile force due to the elastic restoring force of the tie bolt. As a result, the entire ring is tensioned circumferentially.

[Brief description of drawings]

FIG. 1 is a perspective view of a segment of the present invention.

FIG. 2 is a perspective view of another example of the segment of the present invention.

FIG. 3 is a perspective view of still another example of the segment of the present invention.

FIG. 4 is an enlarged partial sectional view of a fixing structure of PC steel material.

[Explanation of symbols]

 10, 12, 14 Flat segment 16 Main body 18, 22 Circumferential end and width end of main body 20, 24 Joint plate 26, 28 PC steel material 30 Joint bolt receiving space 32 Inner peripheral surface of main body 38 Joint bolt hole

Claims (3)

[Claims] 1. A main body made of concrete, which is a flat plate-shaped segment curved in an arc shape and has a plurality of joint bolt receiving spaces and an inner peripheral surface released by the joint bolt receiving spaces.
A plurality of joint plates having joint bolt holes that are embedded in the circumferential end portion and the width direction end portion of the main body and communicate with the respective joint bolt receiving spaces, and the inside of the main body is at least one of the circumferential direction and the width direction thereof. PC steel that is stretched to and secured to both joint plates facing each other and is strained,
Flat segment. 2. The PC steel material is composed of threaded bar rebars, and the ends of the threaded bar rebars are screwed into a cone that is received in a hole provided in the joint plate and is wedged.
The segment of claim 1. 3. A plate member that is embedded in a circumferential end portion of the main body and is located closer to the outer peripheral surface side of the main body than the joint plate, and both joints that extend in the circumferential direction inside the main body and face each other. A segment according to claim 1 comprising PC steel anchored to the plate and strained.