JPH06280494A - Structure of joint between segment rings in shield method - Google Patents

Abstract

PURPOSE:To make it possible to reduce the thickness of a segment in comparison with that of a conventional one, to have also shear resistance sufficiently between rings, to make it possible to satisfy sufficiently the transfer of thrust and to enable the reduction of manufacturing and built-up cost without requiring any coupling bolt between segments. CONSTITUTION:Recessed grooves 11a and 11b toward the peripheral direction lining are arranged to alignment faces of concrete segments 10a and 10b connected to the lining axial side each other in an opposite state. A shear force transferring member 12 is fitted to the insides of both recessed grooves and, at the same time, joint sections 13a, 13b, 14a and 14b are used for thrust transfer faces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between segment rings in a shield construction method, that is, between end faces on the lining axial direction of segments.

[0002]

2. Description of the Related Art Generally, in the shield construction method, each time the excavator is propelled for a certain length, segmented rings 1, 2 which are arcuate plate-shaped as shown in FIG. ... are sequentially extended to form a cylindrical lining 3, and a reaction force is applied to the lining 3 to propel the shield machine, and in recent years, the segment 1 has a segment 1 as shown in FIG. A convex tenon 4 having a trapezoidal cross section is integrally provided on one of the end faces on the lining axial direction side, that is, both end faces on the segment ring side, and a concave tenon 5 having a shape to which the convex tenon 4 is fitted is provided on the other end. A joint structure has been developed in which the concavo-convex tenons 5 and 4 are fitted to each other and connected to each other with a connecting bolt 6 so as to connect the segment rings.

This ring-to-ring joint structure has uneven mortices 4, 5
The shear resistance between the rings is increased by fitting the two.

[0004]

In the conventional segment ring joint structure described above, the thrust force for propelling the shield machine is transmitted through the trapezoidal top faces of the uneven mortises 4, 5. Therefore, the shearing force between the segment rings is countered by fitting the uneven tenon. Therefore, the joining area for transmitting the thrust, that is, the width a of the joining surface must be a certain value or more.

In order to counter the shearing force, stress is concentrated on the jaws 7, 7 on both sides of the concave tenon 5. For the purpose of clarifying the shear resistance mechanism of this joint structure, the present inventor uses flat plate-shaped test pieces 8 and 9 as shown in FIG. A shear test was performed by applying a load as indicated by the arrow. As a result, as shown in FIG. 6, the jaw 7 inside the concave tenon is shown.
Was found to be destroyed at an angle of approximately 45 °.

Therefore, in order to increase the shear resistance between the segment rings, it is necessary to increase the length of the width b of the shear surface from the concave tenon 5 to about 45 °.

As described above, in the conventional joint structure between segment rings, the joint surface width a of the convex and concave mortises 4, 5 and the jaw portion 7,
Since the width b of the shear surface of No. 7 must be increased, the thickness of the segment must be increased, which causes the tunnel excavation cross section to be increased accordingly.

Further, since it is not possible to increase the depth of the recessed tenon due to the need to increase the shear resistance, a connecting bolt, an anchor nut, and a box metal fitting for the bolt hole are required, which results in the manufacturing cost of the segment. However, there is a problem in that it is expensive and requires a lot of work for connecting the rings.

In view of such conventional problems, the present invention makes it possible to make the thickness of the segment thinner than that of the conventional one, to sufficiently secure the shear resistance between the rings, and to sufficiently satisfy the thrust transmission. Further, it is an object of the present invention to provide a joint structure between segment rings in a shield tunnel which can reduce the manufacturing and assembling cost by eliminating the need for connecting bolts between the segment rings.

[0010]

The features of the present invention for solving the above-mentioned conventional problems and for achieving the intended object are to provide the joining surfaces of the concrete segments joined to each other on the axial side of the lining. In the shield construction method in which the concave grooves facing the circumferential direction of the lining are provided in a position facing each other, and the shear force transmitting material is fitted in the both concave grooves, and the joints on both sides of the concave groove serve as thrust transmitting surfaces. It exists in the joint structure between the rake segment rings.

[0011]

In the segment ring inter-joint structure of the present invention, since the thrust transmitting surface is the joint surface on both sides of the concave groove, the width of the shearing surface of the jaws on both sides of the concave groove can be made sufficiently large, and therefore the shearing between segment rings is performed. The resistance is mainly taken up by the shear force transmitting material inserted in the both concave grooves. Since the shearing force transmitting material is manufactured separately from the segments, it is possible to easily increase the shearing resistance even if the width is narrow.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention,
In the figure, 10a and 10b are segments that form segment rings that are joined to each other. Both these segments 10
Concave grooves 11a and 11b are formed in a and 10b at positions substantially opposite to each other in the center of the joint end faces. The shear force transmitting member 12 having a shape corresponding to the cross-sectional area is fitted into a space formed by the concave grooves 11a and 11b facing each other on the entire circumference of the joint surface of the segment ring, thereby connecting the segment rings. is doing.

The material of the shearing force transmitting material 12 is one that can exhibit a shearing resistance substantially equal to or higher than that of the joint concrete of the present invention. For example, metal such as iron, synthetic resin or synthetic rubber. Etc.

Further, the joint surfaces 13a, 13b, 14a, 14b on both sides of the concave grooves 11a, 11b are used as thrust transmitting surfaces,
It is joined via thrust transmitting members 15 and 16 made of a cushioning material such as a rubber material.

In the above-described embodiment, the cross-sectional shape of the void and the shearing force transmitting material formed by the concave grooves facing each other is rectangular, but it may be hexagonal as shown in FIG. It can have various shapes.

[0017]

As described above, according to the present invention, the shearing force between the segment rings is supported by the shearing force transmitting material fitted in the concave grooves formed on both joint surfaces so as to be opposed to each other, and the thrusting force is reduced. The width of the thrust transmitting surface (a in FIGS. 1 and 2 is obtained by supporting the joint surfaces on both sides of the groove).
It is possible to increase the width of the shearing surfaces of the jaws on both sides of the groove (the same portion b), and thus to increase the shear resistance between the segment rings and reduce the segment thickness.

Further, since the joint of this structure has sufficient shear resistance, it becomes possible to obtain a sufficient coupling force between the segment rings without using connecting bolts.
The manufacturing cost of the segment is reduced, the number of assembly steps of the segment is reduced, and the workability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of a joint structure between segment rings of the present invention.

FIG. 2 is a cross-sectional view of another example of the above.

FIG. 3 is a perspective view of a lining by a segment of a conventional shield construction method.

FIG. 4 is a cross-sectional view of a segment ring joint portion of the above.

FIG. 5 is a front view showing a shear test state using a flat plate-shaped test piece.

FIG. 6 is a partial perspective view showing the above sheared state.

[Explanation of symbols]

 10a, 10b Segment 11a, 11b Recessed groove 12 Shear force transmitting material 13a, 13b, 14a, 14b Joining surface 15, 16 Thrust transmitting material

Claims (1)

[Claims] 1. A grooving groove facing the circumferential direction of the lining is provided on each joining surface of concrete segments joined to each other on the axial side of the lining so as to face each other, and a shearing force transmitting material is provided in both of the grooving grooves. The segment ring joint structure in the shield construction method in which the joint portions on both sides of the concave groove are used as thrust transmitting surfaces while they are fitted together.