JPH1122392A - Joint method of steel-made segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have a sufficient proof stress for tension and suppress occurrence of cracks of concrete. SOLUTION: In a method in which a plurality of small cross section shield tunnels are precedently constructed and concrete is placed between a shield tunnel inside and a tunnel, end plates are attached to the entire face for the joining face of a steel-made segment 1 and an adjacent segment. At the time of execution of the small cross section tunnel, the end plates of the adjacent segment 1 are mutually joined by short bolts. Before placing of concrete, additional bolts 4 are tightened to be joined between the segments 1. Furthermore, the inner empty faces of both the segments are fixed by friction joining by bolt tightening by means of splice plates 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining steel segments.

[0002]

2. Description of the Related Art A method for constructing a large-section tunnel as shown in FIG. 4 has been developed. According to this method, a plurality of small-section shield tunnels a are first arranged side by side in the horizontal and vertical directions. Thereafter, the shield tunnels a are connected to each other, and concrete is cast inside the shield tunnels a and between the tunnels a. After constructing the concrete shell in this way, this method is to construct a large-section tunnel by excavating the internal section surrounded by the tunnel group. In this large-section tunnel, a segment main girder is used as a tensile steel material of an RC member.

[0003]

According to the conventional concept of the shield tunnel, the stress generated by the main girder due to the external force is of the type predominant in the axial compression force. For this reason, the tensile stress state in the entire section such as a tunnel having a large section as described above is not considered. Therefore, when the conventional short bolt tensile joining is employed as it is, the cross-sectional area becomes extremely small with respect to the main girder portion, so that there is a problem that the tensile strength is insufficient. A method of using high-tensile steel for short bolts is also conceivable, but in that case, the extension performance of the main girder part is different, so when it becomes an RC member, concentrated cracks may occur, and the member strength It is thought that it will affect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and is intended to provide a steel segment which has a sufficient tensile strength and can suppress the occurrence of cracks in concrete. It is an object to provide a joint method.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a method of joining steel segments according to the present invention comprises first constructing a plurality of small-section shield tunnels, and thereafter connecting the shield tunnels, In the construction method of placing concrete inside the shield tunnel and between the tunnels, steel segments are used, and end plates are attached to the entire surface of the joint between the segment and the adjacent segment, and when constructing a small section tunnel At the time of joining segments, the end plates of adjacent segments are joined to each other with short bolts, and before the concrete section is finished and concrete is cast, additional bolts are fastened to join the segments. Joints of steel segments, where the inner surfaces of both segments are fixed by frictional joining with bolts and bolted joints Law in which was characterized by.

[0006]

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

<A> Shape of segment In the method according to the invention, a steel segment 1 is used. An end plate 2 is attached to the entire joint surface between the segment 1 and the adjacent segment 1.

<B> When constructing a small section tunnel. In the construction of the small-section tunnel, when joining the segments 1, the end plates 2 of the adjacent segments 1 are abutted with each other. Then, the compression side of the end plate 2 with respect to the neutral axis is joined to each other by short bolts 3. The end plate 2 of the segment 1 is provided with a bolt hole, but the short bolt 3 uses, for example, every other bolt hole, and the other bolt holes remain open. Further, the tension side of the neutral shaft is joined to each other by short bolts 3 for tension joining. Such a short bolt 3
Is similar to that of the conventional shield tunnel.

<C> When constructing a large section tunnel. Before connection of the small sections is completed and before concrete is cast, the segments 1 are newly fastened with additional bolts 4. The insertion of the additional bolt 4 is performed using a bolt hole not used during the construction of the tunnel.

<D> Friction welding of the contact plate. At the same time as fixing with the additional bolt 4 between both segments 1,
The inner side of segment 1 is fixed. For this purpose, the attachment plate 6 is fixed to the lower surface of the end plate 7 fixed to the flanges of the two main girders, that is, the inner surface of the segment 1 from the inside by frictional joining by bolting. Since the bolting of the attachment plate 6 is performed from the inside of the tunnel, it can be performed freely without any obstacle.

[0011]

[Effects of the present invention] Since the joint method of the steel segment 1 of the present invention is as described above, the following effects can be achieved. <B> Sufficient tensile strength and can suppress the occurrence of cracks in concrete. <B> When constructing a shield tunnel, fasten the segments with only short bolts and connect the tunnels to RC.
In the case of a structure, a method of newly installing an additional bolt and a contact plate only at a portion to be a tensile steel material does not hinder tunnel construction, and can be constructed economically. <C> The occurrence of cracks in concrete, which affects the strength of the RC member, can be suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of a method for joining steel segments according to the present invention.

FIG. 2 is an explanatory diagram of a state at the time of segment fastening.

FIG. 3 is an explanatory diagram of a state in which a bolt is added.

FIG. 4 is an explanatory view of a construction method for constructing a large-section tunnel by using a small-section tunnel.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshifumi Hattori 1-25-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei Corporation

Claims (1)

[Claims] 1. A method of constructing a plurality of small-section shield tunnels in advance, connecting the shield tunnels, and placing concrete inside the shield tunnels and between the tunnels, using a steel segment, and adjoining the segment. End plates are attached to the entire joint surface with the segment to be joined, and when constructing a small section tunnel, when joining the segments, the end plates of adjacent segments are joined to each other with short bolts, and the small section is connected Before the concrete is cast after finishing, additional bolts are fastened to join the segments, and the inner surface of both segments is fixed by friction joining by bolting using an attachment plate The method of joining steel segments