JPH0598896A - Hexagon concrete segment - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] During or after assembly,
(EN) Provided is a hexagonal concrete segment which can prevent cracks and defects from occurring at the top of the concrete segment. [Structure] A hexagonal concrete segment 1 that is connected to each other to form a tubular wall body, in which apex portion 3 of each concrete segment is cut out, and an elastic material is fixed to the cutout portion 3. There is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to hexagonal concrete segments which are connected to each other to form a tubular wall body.

[0002]

2. Description of the Related Art One of the construction methods for constructing a tunnel is a so-called shield construction method in which excavation and segment assembly are performed simultaneously.

[0003] In such a shield construction method, conventionally, a segment mainly used has a rectangular shape in a front view formed in an arcuate cross section or a box shape (core shape).

However, in recent years, there has been a marked tendency for tunnels to become longer and faster, and in order to deal with this, tunnels can be formed with one type of segment, there is no restriction on the order of segment assembly, and there is no shield immediately after assembly. A construction technique using hexagonal concrete segments (also referred to as honeycomb segments) has been developed, which has various advantages such as being able to apply thrust of a jack to the segments.

[0005]

By the way, when the above-mentioned hexagonal concrete segment is used for construction, the above-mentioned various advantages are obtained, but the following drawbacks are involved.

That is, at the time of assembly, the apex portion of the segment to be newly installed comes into contact with or collides with the already assembled segment, resulting in cracks or chips, and after assembly, the propulsive reaction force of the shield jack or the ground. When a load is applied to the concrete segment due to the pressure or the like, stress concentration occurs at the same vertex portion, and cracks or chips are generated as in the above.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a hexagonal concrete segment capable of preventing cracks and defects from occurring at the apex portion of the concrete segment during or after assembly. It is intended.

[0008]

In order to achieve the above object, the invention according to claim 1 is a hexagonal concrete segment which is connected to each other to form a tubular wall body. The feature is that the apex part is cut.

The invention according to claim 2 is characterized in that the apex portion of each concrete segment is cut out, and an elastic material is fixed to the cutout portion.

[0010]

As described above, since the apex portion of the concrete segment, which is the projecting state and is the portion which is most likely to collide or contact at the time of assembly, is cut out or replaced with an elastic material in advance, Even if an impact load is applied, it is possible to prevent damage to that part.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First Embodiment FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a perspective view showing a state in which a plurality of hexagonal concrete segments 1 ... According to the present invention are assembled on the inner surface of a tunnel.

As shown in the figure, all of the concrete segments 1 ... Have the same shape as the front view and have a substantially regular hexagonal shape, and they are lowered from a work shaft (not shown) into the mine by an elevator or crane. Transported to the assembly site at the end of the tunnel by a trolley, and assembled into a honeycomb shape by an elector or human power on the inner peripheral part of the front end that is being dug by a shield machine, and constitutes the inner wall surface of the tunnel which is a tubular wall body as a whole. Is.

A peripheral groove 2 is formed in the concrete segment 1 ... In a substantially central portion of the outer peripheral surface. This peripheral groove 2 is
Seal packing is attached to this part during construction,
It controls the movement of the concrete segments 1 ... In the direction orthogonal to the front surface or the back surface, or functions as a seal portion. Further, at the time of assembly, it is also possible to fit a rod member into the circumferential groove 2 and use it for positioning.

Further, notches 3 (3a, 3b) are formed at the apex portions of the concrete segments 1 ... And the upper and lower portions thereof except the circumferential groove 2. The size of the notch 3 (3a, 3b) is set so as not to cause stress concentration in the portion when an external force is applied. The corners facing the upper surface and the lower surface of the concrete segment of the notch 3 are respectively shown in FIG.
And, as shown in FIG. 3, tapered portions T1 and T2 are formed.

In the illustrated example, the notch 3 is notched in a substantially triangular prism shape, but the invention is not limited to this.
It may be cut out into another shape, for example, a triangular conical shape, or may be cut out so as to have an arcuate cutout surface. The notch 3 can be filled with caulking material such as mortar during construction.

According to the hexagonal concrete segment having the above structure, however, the apex portion of the concrete segment, which is the projecting state and is most likely to collide or contact during assembly, is notched beforehand.
Even if a load is applied to the apex portion due to a collision or the like, damage to the apex portion can be prevented in advance.

Further, even when pressure is applied from the propulsive reaction force of the shield jack or the ground after assembly,
Since the apex portion of the concrete segment where stress concentration is likely to occur is cut out in advance, it is possible to prevent cracks and defects from occurring in this portion.

Second Embodiment FIG. 4 shows a second embodiment of the present invention. In this embodiment, the notch 3 is provided at the top of the concrete segment 1.
However, in this embodiment, an elastic member 4 made of rubber or the like is further fixed to the notch 3. Thus, the apex portion of the concrete segment, which is apt to be damaged or cracked, is replaced with the elastic material 4 in advance. As a method of fixing the elastic material 4, there is a method of using an adhesive material, a method of providing a projection or a concave portion on the joint surface of the elastic material, and a method of fitting the joint portion of the concrete segment 1 in a concavo-convex manner. Even with such a configuration, the same effect as that of the first embodiment described above can be obtained.

[0020]

As described above, according to the present invention, the apex portion of the concrete segment, which is the portion which is in the protruding state and which is most likely to collide or come into contact during assembly, is cut out or replaced with an elastic material in advance. Therefore, even if an impact load is applied to the apex portion, damage to the apex portion can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment showing a state where a concrete segment is assembled to an inner surface of a tunnel.

FIG. 2 is an enlarged perspective view of a vertex portion of a concrete segment.

FIG. 3 is a side view of an apex portion of a concrete segment.

FIG. 4 is a perspective view showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Concrete segment 2 Circumferential groove 3 Notch 4 Elastic material

Front page continuation (72) Inventor Saburo Okuno 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka-shi, Okumura Gumi Co., Ltd. (72) Inventor Hiroki Someya 2-6-21 Yaesu, Chuo-ku, Tokyo Roesbay Yaesu Building Ishikawajima Building Materials Co., Ltd. In-house (72) Inventor Munetaka Ozeki 2-6-21 Yaesu, Chuo-ku, Tokyo Rose Bay Yaesu Building Ishikawajima Building Materials Co., Ltd. In-house

Claims (2)

[Claims] 1. A hexagonal concrete segment which is connected to each other to form a tubular wall body, wherein the apex portion of each concrete segment is cut out. 2. A hexagonal concrete segment interconnected with each other to form a tubular wall body, in which each vertex of the concrete segment is cut out, and an elastic material is fixed to the cutout. A hexagonal concrete segment characterized in that