JP2002081295A - Fastener of segment and joining structure of segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily insert a PC steel material into inserting holes of segments. SOLUTION: The PC steel material 1 of a fastener A is inserted into the inserting holes Sah and Sbh of the segments Sa and Sb, and when pushing the end part 1b in a taper hole 11a of a gripping tool 7, a wedge body 12 retreats by compressing an energizing spring 13, diametrally expands an inserting fixing hole 12h, inserts the end part 1b of the PC steel material l into the fixing hole 12h, is advanced by the enrgizing spring 13 after insertion, diametrally contracts the inserting fixing hole 12h, and grips the PC steel material 1. Every time when installing the segments in an annular shape, the mutual short PC steel materials 1 and 1 are connected by the operation, a fastening nut 3 of a recessed part Sao opened and arranged inside a tunnel is finally fastened, prestress is introduced, and the mutual plural segments are integrally joined. Since a long PC steel material is not required, insertion into the inserting holes is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a segment tightening device for introducing prestress by tightening segments, and to a segment joining structure using the tightening device.

[0002]

2. Description of the Related Art When a tunnel is constructed by annularly connecting a plurality of segments by a shield method, as shown in FIG. 23, the PC steel material 22 is pulled out from the other pipe 24 to the inside of the tunnel, and the PC steel material 22 is pulled and tightened by a hydraulic jack 26 to introduce prestress. It is common to join together. Pipes 21, 24
Are integrally formed with each other by casting, and are embedded in the segment S.

[0003]

In the above conventional method,
Sheath tube 2 communicated in a ring shape with many segments S
3, one long PC steel material 22 must be inserted. However, if the entire length of the sheath tube 23 is long, the insertion resistance of the PC steel material 22 becomes large, and a molding error or an assembly error between the sheath tubes 23 is caused. Step is likely to occur due to
There is a problem that the insertion of the C steel material 22 is not easy and it takes time and effort.

Further, in order to draw both ends of the PC steel material 22 into the inside of the tunnel, the pipes 21 and 24 and the embedding thereof are indispensable, which increases the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a segment tightening device and a segment joining structure capable of easily inserting a PC steel material into a segment insertion hole to introduce prestress. Another object of the present invention is to provide a PC
An object of the present invention is to provide a segment tightening device and a segment joining structure which can reduce costs without requiring a pipe for drawing a steel material into a tunnel.

[0006]

In order to achieve at least one of the above objects, the invention according to claim 1 is provided at one or both ends of a PC steel material inserted into an insertion hole provided in a segment. A tightening bolt is attached, and the tightening bolt is provided with a tapered tapered hole at one end and a threaded portion screwed to the tightening bolt at the other end, and a PC steel material at the center of each other. A plurality of wedge bodies which are inserted into the tapered hole so as to be movable in the longitudinal direction of the cylindrical body by forming an insertion fixing hole and being annularly arranged and having an outer peripheral surface touching an inner peripheral surface of the tapered hole; The wedge body is urged toward the small-diameter distal end of the tapered hole so that the diameter of the insertion fixing hole is reduced, and a gripper having an urging spring provided in the cylinder is provided.

In this means, when the end of the PC steel material is pushed into the cylindrical body of the gripping tool which is mounted by screwing the screw portion to the tightening bolt, each wedge body retreats against the elasticity of the urging spring. Then P
The insertion fixing hole is expanded in diameter by the pushing force of the C steel material, and the end of the PC steel material is inserted into the insertion fixing hole. After inserting the PC steel into the insertion fixing hole, stop pushing the PC steel,
The wedge body advances by the urging force of the urging spring to reduce the diameter of the insertion fixing hole, and grips the PC steel. When the PC steel material is gripped by the gripper, the wedge body is moved together with the PC steel material to the tip end side of the small diameter of the tapered hole with respect to the removal of the PC steel material to further reduce the diameter of the insertion fixing hole, thereby reducing the gripping force. Since it is strengthened, it is not possible to pull out the PC steel from the gripper.

The above operation is performed each time the segment is assembled, and finally, a prestress is introduced by screwing a tightening nut onto a tightening bolt at the extreme end of the PC steel material connected by the gripper and tightening. Join multiple segments together.

Normally, one PC steel material is used by being inserted into one or more insertion holes of one or more segments. However, two or more PC steel materials are connected by a gripping tool and the insertion hole of one segment is used. It may be inserted through. A segment in which a PC steel material having fastening bolts attached to both ends thereof is inserted into the insertion hole can have a longer length as a base segment, and the other segments can be reduced accordingly.
As the PC steel, a strand of PC steel is usually used, but a steel rod or the like can also be used. The insertion hole is usually formed by a sheath tube. There are no restrictions on the structure, type or shape of the segments.

According to a second aspect of the present invention, the segments of the fastening device according to the first aspect of the present invention, in which the PC steel material is inserted through the insertion holes, are gripped by the gripping tool of the other segment. Then, the joining surfaces where the insertion holes were opened were brought into contact with each other, and a prestress was introduced into the PC steel material so as to be integrally joined.

According to this means, it is not necessary to insert a long PC steel material into the insertion holes of a plurality of segments as in the prior art.
Each time a segment is assembled, a short PC steel material is inserted through the insertion hole of the segment to sequentially connect the steel materials to a longer length, thereby introducing prestress.

According to a third aspect of the present invention, the PC steel material of the tightening device according to the first aspect is inserted into each of the insertion holes provided between the two sets of joining surfaces of the oblique sides facing each other.
In a joint structure of segments in which hexagonal segments are joined together by introducing prestress into a steel material, one end of the PC steel material is fixed to a joint surface on the oblique side.

This means does not require a conventional pipe for drawing one end of the PC steel material, that is, the start or end of the PC steel material, into the inside of the tunnel.

[0014]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 5 show an embodiment of the present invention. In these figures, reference numeral A denotes a segment tightening device, which is provided with a PC steel material 1, a tightening bolt 2, a tightening nut 3, washers 4, 5, and a gripper 7.

The PC steel material 1 is made of a steel strand having appropriate flexibility, and can be inserted through the insertion holes Sah, Sbh formed by the sheath tube 9 in the rectangular segments Sa, Sb.

The fastening bolt 2 is integrally attached to the end 1a of the PC steel material 1 by an attachment means such as welding or caulking. A tightening nut 3 is screwed onto the tightening bolt 2, and a washer 4 is fitted into the tightening bolt 2 so that the tightening nut 2 can be locked to the step Sad of the insertion hole Sah. Washer 5
It is used by being locked to the step Sbd of the insertion hole Sbh.

The grip 7 includes a cylindrical body 11 and a plurality of wedge bodies 12.
And a biasing spring 13. A tapered tapered hole 11a is provided at one end of the cylindrical body 11, and a threaded portion 1 is provided at the other end.
1b is provided. The cylindrical body 11 can be attached to the tightening bolt 2 by screwing the screw portion 11b.

Each wedge body 12 has a PC steel material 1 at the center of each other.
With the insertion fixing hole 12h formed and annularly arranged, the outer peripheral surface thereof is brought into contact with the inner peripheral surface of the tapered hole 11a, and is inserted into the tapered hole 11a so as to be movable in the longitudinal direction of the cylindrical body 11. I have.

The biasing spring 13 biases each wedge body 12 toward the tip end of the tapered hole 11a so as to reduce the diameter of the insertion fixing hole 12h. Is provided. The fixing plate 15 is fixed to the cylinder 11.

The segment tightening device A having the above-described structure, for example, allows the PC steel material 1 to be inserted through the insertion holes Sah and Sbh of the segments Sa and Sb, and the end 1b of the holding member 7 in the connection hole Sbr. When pushed into the tapered hole 11a,
The wedge body 12 compresses the biasing spring 13 and retreats to the right in FIGS. 1 and 2, and the insertion fixing hole 12 h is pressed by the pushing force of the PC steel material 1.
And the end 1b of the PC steel material 1 is inserted into the fixing hole 12h.
Insert.

When the pushing of the PC steel 1 is stopped in this state, the wedge body 12 is advanced by the biasing spring 13 to reduce the diameter of the insertion fixing hole 12h. For this reason, the PC steel 1 is the wedge 1
2 will be grasped. PC steel 1 to cylindrical body 1
Even if the wedge body 12 is to be pulled out from the base material 1, the wedge body 12 follows the PC steel material 1 and is moved toward the distal end of the tapered hole 11a to further reduce the diameter of the insertion fixing hole 12h to increase the gripping force.
The steel material 1 cannot be pulled out of the gripper 7.

Each time the segments are assembled in a ring, the PC steel materials 1 and 1 are connected by the above operation. And
Lastly, for example, a prestress is introduced by tightening the tightening nut 3 of the concave portion Sao provided inside the tunnel, and a plurality of segments are integrally joined.

In the insertion hole Sch of the segment Sc shown in FIG. 4, a PC steel material 1 in which a fastening bolt 2 is attached to both ends and a holding tool 7 is screwed is inserted.
The PC steel material 1 in which the fastening bolt 2 is attached to one end and the holding tool 7 is screwed is inserted into the insertion hole Sdh of d.

FIG. 1 shows a PC steel material 1 of the segments Sa and Sb.
And the connection state of the PC steel material 1 of the segment Sc or the segment Sd.
Connection of C steel materials 1, 1 and PC of segments Sd, Sd
The connection of the steel materials 1, 1 is basically the same as described above. The connection holes Sbr are provided in other segments Sa, Sc, and Sd as necessary, for example, as indicated by a two-dot chain line in FIG.
The segment Sc has a longer length as a base segment than the other segments Sa, Sb, and Sd.

The segments Sa, Sb, Sc, and Sd are joined surfaces Saf, Sbf, Scf, and Sdf where the insertion holes are opened.
Is brought into contact with the joining surface of another segment to be joined.

FIG. 6 shows an example of joining hexagonal segments Sm. In this example, the joining surfaces Sm of the oblique sides facing each other
Six segments Sm provided with insertion holes (not shown) between f and Smf make the joining surfaces Smf abut each other to form an annular shape (actually in the longitudinal direction of the tunnel (up and down direction in FIG. 6)). Are pre-stressed and joined by three PC steel materials 1 which are inserted into the insertion holes and integrally connected by the gripper 7. The gripper 7 is screwed to the tightening bolt 2 attached to the end of the PC steel material 1 as described above.

In FIG. 6, a portion where two tightening bolts 2 are provided adjacent to each other is a tightening portion of the PC steel material 1, which is sequentially shifted by one segment Sm. The structure of the tightening device A and the basic structure of the segments are the same as those in FIGS.

FIG. 7 shows a case where the PC steel material 1 is inserted into insertion holes (not shown) provided between the two sets of joining surfaces Smf and Smf of the oblique sides facing each other to introduce prestress and to apply segments. This is an example of bonding Sm.
The two insertion holes between the two sets of joining surfaces Smf, Smf are formed so as to intersect in an X shape in plan view without being shifted in the thickness direction of the segment Sm and communicating with each other. Since the other structure is the same as that of FIG. 6, the same members and the like are denoted by the same reference numerals and description thereof is omitted.

FIGS. 8 to 10 show three insertion holes Svh.
7 is a joining example of a hexagonal segment Sv having a hexagonal segment and another hexagonal segment Sw having two insertion holes Swh.

The two insertion holes Svh of the segment Sv are
Between the two sets of joining surfaces Svf and Svf of the oblique sides facing each other, the end on the face side is opened at the 3/8 position (see FIG. 9), and the end on the wellhead side is opened at the 6/8 position. It is provided so as to intersect in an X shape in a plan view without being communicated with each other while being shifted in the thickness direction, and is provided with another insertion hole Svh.
Are provided in the 2/8 position in parallel with the side. Also,
The two insertion holes Swh of the segment Sw are provided at the 2/8 position and the 6/8 position in such a manner that both ends are opened to the joint surface Swf and are parallel to the side.

In this example, as shown in FIG. 8, two segments Sv and four segments Sw are joined to the joint surfaces Svf,
Swf and the insertion holes Svh and Sw
h are communicated with each other and are assembled in an annular shape.
h, PC steel material 1 of the tightening device A inserted through Swh
(Not shown) and joined by introducing prestress. In addition, the tightening of the PC steel material 1 is 3/3 of the insertion hole Svh.
Perform at the end of 8 positions.

In the joint structure shown in FIG.
24 (FIG. 11) is unnecessary, and the cost can be reduced.
Also, the arrangement is simplified. Joint surfaces Svf, Svf, Sw
segments Sv and Sw in which the angle α of f and Swf is 120 degrees
The prestress is more easily applied to the segments Sv and Sw of 150 to 180 degrees than to the segments Sv and Sw.

Segments Sa, Sb, Sc, Sd, Sm
It is also possible to provide the pipes 21 and 24 of FIG. 11 and draw out the end of the PC steel material 1 inside the tunnel to introduce prestress. The joining structure is not limited to the above, and can be variously changed.

[0034]

As described above, according to the first or second aspect of the present invention, a short PC steel material is inserted into an insertion hole in accordance with the progress of assembly of a segment, and some PC steel materials are lengthened. Can be added. Therefore, it becomes easy to insert the PC steel material into the insertion hole of the segment, and the joining operation can be performed efficiently and the construction period can be shortened.

Further, according to the third aspect of the present invention, there is no need for a pipe for drawing out the PC steel material inside the tunnel, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the gripper.

FIG. 3 is a front view of a wedge body.

FIG. 4 is a schematic front view of an annularly joined segment.

FIG. 5 is a schematic plan view of a segment.

FIG. 6 is a schematic development view showing another example of joining segments.

FIG. 7 is a developed schematic diagram showing another example of joining segments.

FIG. 8 is a developed schematic view showing still another example of joining segments.

FIG. 9 is a schematic plan view of the segment of FIG. 8;

FIG. 10 is also a side view.

FIG. 11 is a schematic front view showing a conventional segment joining structure.

[Explanation of symbols]

A Tightening device Sa, Sb, Sc, Sd, Sm, Sv, Sw Segment Sah, Sbh, Sch, Sdh, Svh, Swh Insertion holes Saf, Sbf, Scf, Sdf, Smf, Svf, Sv
wf Joining surface 1 PC steel 1a, 1b End 2 Tightening bolt 3 Tightening nut 7 Gripping tool 9 Sheath tube 11 Cylindrical body 11a Tapered hole 11b Screw portion 12 Wedge body 12h Insert fixing hole 13 Biasing spring

Claims (3)

[Claims] 1. A tightening bolt is attached to one end or both ends of a PC steel material inserted into an insertion hole provided in a segment, and the tightening bolt has a tapered tapered hole at one end and the other end. And a cylindrical body provided with a screw portion to be screwed to the tightening bolt, and a PC steel material insertion fixing hole is formed in the center of each other and annularly arranged, and the outer peripheral surface is formed on the inner peripheral surface of the tapered hole. A plurality of wedges which are inserted into the tapered holes so as to be movable in the longitudinal direction of the cylindrical body, and bias the wedges toward the small diameter tip side of the tapered holes so as to reduce the diameter of the insertion fixing holes. And a gripper having a biasing spring provided in the cylindrical body. 2. The segment in which the PC steel material of the fastening device according to claim 1 is inserted through the insertion hole, the end of the PC steel material of one segment is gripped by the gripper of the other segment, and the insertion hole is formed. A joining structure of segments, wherein the opened joining surfaces are brought into contact with each other, and prestress is introduced into the PC steel material to be joined integrally. 3. The PC steel material of the tightening device according to claim 1, wherein the PC steel material is inserted into each of the insertion holes provided between the two sets of the joining surfaces of the oblique sides facing each other, and a hexagonal segment is formed by introducing prestress into the PC steel material. What is claimed is: 1. A joining structure of segments, wherein one end of the PC steel material is fixed to a joining surface of a hypotenuse.