JPH11210390A - Segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength by installing joints having a structure to extend a PC steel material on both ends of the PC steel material penetrated in the tunnel circumferential direction of a segment. SOLUTION: A PC steel material 2 which has a female joint 3 and a male joint 4 on both ends and is covered with a sheath material 21, is penetrated in the tunnel circumferential direction of a segment 1. Next, a groove-shaped recessed part 12 to arrange the joints 3, 4 is arranged on the connecting surface of the segment 1 so that the groove depth of the recessed part 12 is set to a degree of slightly projecting the joints 3, 4 from the connecting surface. For example, the joint 3 is formed as a cylindrical body having a taper hole, and the joint 4 is formed as a truncated cone-shaped wedge body. At execution work, when the segment 1 is pushed in from the working face side by a jack of a shielding machine, since the joint 4 is inserted into the joint 3, the steel material 2 is pulled to introduce prestress. Therefore, since uniform prestress is introduced over the whole segment, an effective internal water pressure meansure can be taken, so that the segment can be connected only by pushing in the segment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to segments.

[0002]

Conventionally, in a shield method or the like, connection between segments is performed by bolts. By the way, if water pressure acts on the shield, axial compression force in the circumferential direction of the shield may be lost. Therefore, uniform prestress is introduced over the entire circumference of the shield. Is required. However, it is difficult to introduce a uniform prestress into the segments by the connection method using bolts. In addition, since a large number of bolts are required for connection, a large amount of labor is required for fastening work. Further, post-processing such as concrete filling of the bolt box is complicated.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and can introduce an effective pre-stress into the segments so that the internal water pressure can be effectively prevented. An object is to provide a segment that can reduce labor.

[0004]

As a means for solving the above-mentioned problems, the present invention provides a method in which a PC steel material is disposed so as to penetrate in the circumferential direction of a tunnel of a segment, and is connected to both ends of the PC steel material. A segment provided with a joint having a structure for extending a steel material is provided.

In the above segment, the joint is
A segment characterized by comprising a female joint having a tapered hole and a male joint having a tapered wedge body fitted into the tapered hole.

[0006] In the above segment, the joint is
A segment is provided, wherein the segment is mounted in a recess provided in a connecting surface of the segment.

Further, in the above segment, there is provided a segment characterized in that a PC steel material is covered with a sheath material and embedded in a concrete segment. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <A> Shape of segment As shown in FIG. 1, a segment 1 is made of concrete. A groove-like concave portion 12 for installing a joint is formed in the connecting surface 11 at both ends of the tunnel of the segment 1 in the circumferential direction.

As shown in FIG. 2, the recess 12 is provided continuously over the axial direction of the tunnel. In addition, the groove depth of the concave portion 12 is set to such a depth that a later-described joint slightly protrudes from the connecting surface 11 of the segment 1 as shown in FIG.

<B> PC Steel As shown in FIG. 1, an unbonded type of PC steel 2 covered with a sheath material 21 is used. In addition, when they are arranged in an arc shape along the segment 1, those having a length whose both ends are located on the bottom surface of the concave portion 12 are used.

<C> Joint A female joint 3 and a male joint 4 are integrally connected to both ends of the PC steel material 2. The female joint 3 and the male joint 4 are configured to extend the PC steel material 2 by being connected to each other.

For example, as shown in FIG.
Is formed by integrally forming a tubular body 32 with a T-shaped bracket 31 joined to one end of the PC steel material 2. The cylindrical body 32 has a tapered hole 33 and is formed in a truncated cone shape or the like. Then, a slit 34 is formed in the axial direction of the cylinder 32 opposite to the bracket 31.

On the other hand, the male joint 4 is formed by integrally forming a wedge body 42 such as a truncated cone with a T-shaped bracket 41 joined to one end of the PC steel material 2. The wedge body 42 matches the inside of the tapered hole 33 of the female joint 3 and exhibits a wedge function. The shape of the joint may be any other than the above as long as it has a wedge function.

<D> Manufacture of the segment When the segment 1 is manufactured, the PC steel material 2 in which the female joint 3 and the male joint 4 are joined at both ends is arranged at a predetermined position in the formwork, and the concrete is poured. . As a result, FIG.
As shown in the figure, the PC steel material 2 can be arranged in a circular arc shape in the circumferential direction of the tunnel of the segment 1.

The female joint 3 and the male joint 4 are previously inserted into the concave portion 12 of the segment 1 at the time of manufacturing the segment 1 so that the axes of the cylinder 32 and the wedge 42 are parallel to the axis of the tunnel. Place it.

The number of buried PC steel materials 2 is two in FIG. 2, but one or three or more can be selected as appropriate. The segments may be made of steel other than concrete. In this case, the PC steel material 2 may be provided by projecting a bracket for holding the PC steel material 2 on the inner surface of the segment.

[0017]

[Operation] As described above, the segment 1 is manufactured at the factory, and the PC steel 2 to be charged is 10 Kgt / kg to prevent slack.
It is advisable to introduce a light prestress of about ² cm2.

To assemble the segment 1, the strong jack of the shield machine is used to push in the segment 1 from the face side. At this time, as shown in FIGS.
Is inserted into the cylindrical body 32 of the female joint 3.

Then, in the process of inserting the wedge body 42 into the cylindrical body 32, the PC steel material 2 is pulled toward the joint as shown in FIG. The amount of tension at this time is half of the prestress to be introduced.

Then, by connecting the joints on the other end side, a predetermined prestress can be introduced into the PC steel material 2. The above operation is repeated to assemble the segment ring. As shown in FIG. 6, since the entire segment ring can be connected by the series of PC steel materials 2 and the joints 3, 4, a substantially uniform prestress can be introduced to the entire segment ring.

In the final closing segment (key segment) of the segment ring, adjusting nuts are provided at the joints 3 and 4 for adjusting and controlling the prestress to be introduced. Further, grout is preferably injected into the joints 3 and 4 and the sheet material 21 to prevent corrosion.

[0022]

Since the present invention has been described above,
The following effects can be obtained. <A> Since the entire segment ring can be connected by a series of PC steel materials and joints instead of a partial connection structure like a bolt, a substantially uniform prestress can be introduced to the entire segment ring. Therefore, effective countermeasures against internal water pressure are possible.

<B> Since the segments can be connected only by pushing the segments and connecting the joints, the labor for assembling the segments can be reduced.

<C> There is no need to use a jack dedicated to PC for introducing prestress, and the powerful jack of the shield machine can be used effectively.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a segment of the present invention.

FIG. 2 is an explanatory view of a joint portion.

FIG. 3 is an explanatory view of a joint connecting process.

FIG. 4 is an explanatory view of a joint connecting process.

FIG. 5 is an explanatory view of a joint connecting process.

FIG. 6 is an explanatory view showing an operation.

Claims (4)

[Claims] 1. A segment in which a PC steel material is arranged so as to penetrate in a circumferential direction of a tunnel of the segment, and joints having a structure for connecting and extending the PC steel material are attached to both ends of the PC steel material. 2. The segment according to claim 1, wherein
The segment is characterized in that the joint comprises a female joint having a tapered hole and a male joint having a tapered wedge that fits into the tapered hole. 3. The segment according to claim 1, wherein the joint is mounted in a recess provided in a connecting surface of the segment. 4. A segment according to claim 1, wherein the PC steel material is covered with a sheath material and embedded in a concrete segment. .