JP4074488B2 - Steel segment and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a steel segment used when constructing pipes such as water and sewage, subways, power / communication cable joint grooves, water discharge tunnels, etc. by a shield construction method, etc., which is particularly superior in structure and economical. Also related to an excellent steel segment.
[0002]
[Prior art]
When installing water and sewage systems, subways, common grooves for power / communication cables, water discharge tunnels, etc. in the basement, a shield machine is used to form a drilling hole, and a steel segment is assembled behind the shield machine to build a tunnel. The construction method has been widely applied.
[0003]
The steel segment used in this shield method is generally composed of a main girder, joint plate, vertical rib, and skin plate. The main girder and joint plate are fixed to the four edges of the skin plate by fillet welding. Thus, it is a box-type structure with the open side of the tunnel open. The steel segment plays a very important role in the shield method because it takes on the reaction force of the shield machine propulsion during construction and becomes the primary lining body of the tunnel when construction is completed.
[0004]
Further, each component of the steel segment will be described. The skin plate functions to prevent infiltration of groundwater into the tunnel and to resist soil pressure acting on the tunnel integrally with the main girder. The main girder also resists the compressive force, bending moment and shearing force of the tunnel circumferential section, and also functions as a connecting material with segments adjacent in the tunnel axis direction.
[0005]
Furthermore, the joint plate of a steel segment is mainly used as a connecting material with a segment adjacent in the circumferential direction of the tunnel. The vertical ribs are welded to the main girder and the skin plate, and are integrated as a part of the steel segment. The vertical rib has a function as a fixing point of the skin plate to which soil water pressure directly acts, and a function to receive a reaction force of a jack for propelling the shield machine during construction of the shield tunnel.
[0006]
[Problems to be solved by the invention]
However, in conventional steel segments, weld defects such as cracks, undercuts, and slag entrainment are likely to occur at the fillet welds between the joint plate and skin plate during production, ensuring watertightness as the primary lining body. There was room for improvement. In particular, in shield tunnels used at large depths, the earth covering becomes larger than the segment diameter, so in the conventional standard segment for shield construction, water leakage due to welding defects tends to occur easily at the joint plate portion.
[0007]
In addition, the degree of freedom in designing the joint plate may be limited due to the procurement of materials and the like, and in order to cope with a high earth pressure, the plate thickness may be excessive and uneconomical. In other words, the bond strength between steel segments in tunnel lining is mainly borne by the bond structure in the tunnel axis direction (between segment rings) of the steel segment, and is almost borne by the bond structure in the tunnel circumferential direction (between segments). Not. Therefore, the joint structure in the circumferential direction of the tunnel with the joint plate does not require a strong engagement structure between the segment rings by the main girder, so the joint plate thickness is set excessively There is also.
[0008]
On the other hand, the joint plate, like the longitudinal rib, plays the role of transmitting the shield jack thrust and flowing the external load acting on the skin plate to the main girder, but these are only secondary roles. That is, in the joint structure of the tunnel circumferential direction by the joint plate, the problem is not so great even if the plate structure is thin as long as the water stoppage can be secured.
[0009]
The present invention has been made to solve the above-mentioned problems of the prior art, and its purpose is to form a skin plate and a joint plate continuously and integrally, thereby being structurally superior and economical. To provide a steel segment.
[0010]
[Means for Solving the Problems]
The steel segment of the present invention is a steel segment 1 composed of a skin plate 2 and two main girders 3 and 3, and the skin plate 2 is tunneled to the end portion in the circumferential direction of the tunnel of the skin plate 2. A circumferential joint portion 2a formed by bending toward the inner space is provided, the main girder 3 extends in the tunnel circumferential direction and is arranged in parallel, and the main girders 3 and 3 are arranged on the skin plate 2. One side of the longitudinal rib of the L-shaped cross section is welded between the two main girders 3 and 3 on the inner surface of the segment of each circumferential joint 2a and welded to the tunnel axial end 2b and the circumferential joint 2a. wherein said longitudinal ribs 4, a bolt insertion hole which is opened in the circumferential joint extending in two both main beam 3,3 is arranged closer to the back to back abutting the tunnel axis direction in contact Bolts drilled in vertical ribs Respectively attached to the through-holes coincide,
Further, separately from the vertical ribs 4 provided on the inner side surface of the segment of the circumferential joint portion, it is arranged across the two main girders 3 and 3 at a position away from the circumferential joint portion 2a in the circumferential direction. In addition, a longitudinal rib 6 extending in the tunnel axis direction that contacts both the two main girders 3 and 3 is attached to the main girders 3 and 3.
[0011]
The steel segment 1 of the present invention is manufactured as follows. That is, after forming the respective skin plates circumferential joint portion 2a by bending both ends of the tunnel circumferential skin plate 2 by pressing, extending tunnel circumferentially tunnel axial end portion 2b of the skin plate 2 The main girders 3 and 3 are arranged in parallel, the main girders 3 and 3 are welded to the tunnel axial direction end portion 2b and the circumferential joint portion 2a of the skin plate 2, and 2 on the inner side surface of the segment of the circumferential joint portion. Longitudinal ribs extending in the direction of the tunnel axis that are arranged back-to-back in a surface contact state between the main girders 3 and 3 and are in contact with both of the two main girders are attached respectively , and the circumferential joint portion Separately from the longitudinal ribs 4 provided on the inner surface of the segment, the two ribs are arranged between the two main girders 3 and 3 at a position away from the circumferential joint portion 2a in the circumferential direction. Vertical ribs 6 which extend both digit 3,3 to contact with the tunnel axis is characterized in that it is manufactured attached to the main girder 3,3.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The steel segment 1 of the present invention includes a skin plate 2, two main girders 3 and 3, and a plurality of vertical ribs 4. The steel segments 1 are connected in the circumferential direction of the tunnel to form a segment ring, and the segment ring is connected in the tunnel axial direction to form a tunnel covering body.
[0013]
The skin plate 2 is a rectangular steel plate curved in an arc shape along the circumferential direction of the tunnel, and a circumferential joint portion 2a continuous with the skin plate 2 is formed at both ends in the circumferential direction of the tunnel.
[0014]
Both ends of the skin plate 2 in the circumferential direction of the tunnel are bent at a substantially right angle by press working toward the inner side of the tunnel (inward direction of the arc), and the circumferential joint portion 2a is bent at the bent portion of the skin plate 2. It is configured. That is, in the present invention, the skin plate 2 and the circumferential joint portion 2a are continuously formed by press working, and therefore, due to a weld defect from a portion of the tunnel circumferential direction joint structure like a conventional steel segment. There is no leakage.
[0015]
In addition, L rib-shaped vertical ribs 4 are attached to the inner surface of the segment of each circumferential joint portion 2a back to back in a surface contact state. The vertical rib 4 may be formed by bending a flat steel, or a commercially available angle material may be used.
[0016]
The vertical rib 4 is integrated with each circumferential joint portion 2a, and plays a role of transmitting an external force such as a thrust force of the shield jack acting on the circumferential joint portion 2a and earth water pressure acting on the skin plate to the main girder 3. Yes. In the segment of the prior art, since the external force such as the thrust of the shield jack and the earth and water pressure acting on the skin plate is transmitted also by the joint plate, the thickness of the joint plate is larger than necessary. Therefore, in the present invention, the circumferential joint portion 2a is reinforced with the longitudinal ribs 4 so that the thickness of the portion corresponding to the conventional joint plate can be easily adjusted, and the degree of freedom in design is ensured while ensuring high water tightness. It is improving.
[0017]
A bolt insertion hole 5 is formed in the circumferential joint portion 2a and the vertical rib 4. By inserting a bolt, a connecting pin, or the like into the bolt insertion hole 5, the adjacent segments in the tunnel circumferential direction are mutually connected. Can be connected to.
[0018]
Further, two arc-shaped main girders 3 and 3 extending in parallel along the circumferential direction of the tunnel are disposed on the tunnel axis direction end 2b on the inner side of the tunnel of the skin plate 2, respectively. A bolt insertion hole 5 is opened in the main girder 3, and by inserting bolts or connecting pins into the bolt insertion hole 5, segments adjacent in the tunnel axis direction can be connected to each other. ing.
[0019]
The main girders 3 and 3 are fixed to the tunnel axis direction end portion 2b of the skin plate 2, the circumferential joint portion 2a, and the vertical rib 4 by fillet welding. In the steel segment 1 of the present invention, the circumferential joint portion 2a and the main girder 3 are erected on the inner side of the tunnel so as to surround the periphery of the skin plate 2, and the skin plate 2, the circumferential joint portion 2a and the main joint 3 The girder 3 constitutes a box-shaped steel shell with the open side in the tunnel open. In addition, you may attach suitably the vertical rib 6 extended in a tunnel axial direction inside a segment as needed. The vertical rib 6 may be the same as the vertical rib 4 attached to the circumferential joint, or may be different from the vertical rib 4 in size and cross-sectional shape.
[0020]
Further, the production of the steel segment of the present invention is performed by the following steps.
(1) First, both end portions of the skin plate 2 in the tunnel circumferential direction are bent by press working to form the circumferential joint portion 2a on the skin plate 2.
(2) the segment sides of the two circumferential joints 2a, attaching one side of the longitudinal ribs 4 of the L-shaped cross section back to back in a surface contact state. Further, if necessary, the longitudinal rib 5 extending in the tunnel axis direction is disposed on the inner side of the skin plate 2 in the tunnel.
(3) The main girders 3 and 3 extending in the tunnel circumferential direction are arranged in parallel at the tunnel axial direction end portion 2b of the skin plate 2. The main girders 3 and 3 are welded to the tunnel axial end 2b and the circumferential joint 2a of the skin plate 2. When the steel segment 1 has the vertical rib 6, the main girder 3 and the vertical rib 6 are welded.
[0021]
【The invention's effect】
In the present invention, since the skin plate and the circumferential joint are continuously formed by press working, water leakage due to welding defects is caused from the joint structure portion in the circumferential direction of the tunnel like a conventional steel segment. It does not occur.
[0022]
In addition, vertical ribs with L-shaped cross-sections are attached back to back in the surface contact state on the inner surface of the segment of each circumferential joint, and the circumferential joint is reinforced with vertical ribs, equivalent to a conventional joint plate The thickness of the portion to be adjusted can be easily adjusted, the degree of freedom in design is improved while ensuring high water tightness, and an economical segment can be realized. The steel segment of the present invention is suitable for temporary structural segments with a short service life because it has excellent design flexibility and economy, and it can also be used for permanent structures with reinforcement. Since it can, the application range is extremely wide.
[Brief description of the drawings]
FIG. 1 (a) is a perspective view of a steel segment of the present invention from the air side inside a tunnel, and FIG. 1 (b) is a cross-sectional view taken along line AA in FIG.
FIG. 2 (a) is a perspective view of a steel segment of the present invention from the tunnel ground side, and FIG. 2 (b) is a partially enlarged view of (a) seen from the tunnel circumferential direction.
FIG. 3 is an exploded view of the steel segment of the present invention.
[Explanation of symbols]
1 Steel Segment 2 Skin Plate 2a Circumferential Joint 2b Tunnel Axial End 3 Main Girder 4 Vertical Rib 5 Bolt Insertion Hole 6 Vertical Rib

Claims (2)

A steel segment composed of a skin plate and two main girders, and a circumferential joint formed by bending the skin plate toward the inner side of the tunnel at both ends in the tunnel circumferential direction of the skin plate is provided, wherein the main beam is parallel arranged elongated tunnel circumferential direction, and the main girder is welded to the tunnel axis end and the circumferential joint portion of the skin plate, each circumferential joint One side of an L-shaped longitudinal rib is arranged back-to-back in the surface contact state between the two main girders on the inner surface of the segment, and extends in the tunnel axial direction in contact with both of the two main girders The vertical ribs are respectively attached so that the bolt insertion holes opened in the circumferential joint portion and the bolt insertion holes opened in the vertical ribs coincide with each other ,
Further, separately from each of the vertical ribs provided on the inner surface of the segment of the circumferential joint portion, the two are arranged between the two main girders at a position away from the circumferential joint portion in the circumferential direction. A steel segment characterized in that longitudinal ribs extending in the tunnel axial direction that contact both of the main girders are attached to the main girders . A method for producing a steel segment according to claim 1, after forming respectively a circumferential joint to skin plate by bending the tunnel circumferential both end portions of the skin plate by press working, the skin plate The main girder extending in the tunnel circumferential direction is disposed in parallel at the tunnel axial direction end of the tunnel plate, the main girder is welded to the tunnel axial direction end and the circumferential joint portion of the skin plate, and the segment of the circumferential joint portion A steel characterized in that longitudinal ribs extending in the direction of the tunnel axis are attached to the inner side surface in back-to-back contact with each other between the two main girders and abut against both of the two main girders. A manufacturing method for a segment.

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