JP2006207217A - Cutoff structure of shield tunnel forming cruciform joint portion, and method of forming corner portion of water-swelling sealing material for use therein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutoff structure of a shield tunnel having a cruciform joint portion, which exerts excellent cutoff performance enduring high water pressure, and does not adversely effect a segment due to excessive volume of a sealing material at a corner portion, and to provide a method of forming the corner portion of the sealing material for use in the cutoff structure. <P>SOLUTION: The tunnel structure is constructed by connecting a number of rectangular curved segments to each other, and a boundary surface of the mutually adjacent segments connected together in a tunnel circumferential direction and a boundary surface of the mutually adjacent segments connected together in a tunnel axial direction, cooperatively form the cruciform joint portion. The shield tunnel cutoff structure is applicable to the tunnel structure thus constructed, and set up by continuously attaching the band-shaped water-swelling sealing materials to connection surfaces of the respective segments. Herein each of recessed and projected corners of the water-swelling sealing materials abutting on each other along the cruciform joint portion, is finished almost at right angles, and at least one of projected corner ends at the corner portion is reduced in thickness. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water stop structure between joints of segments in a shield tunneling method and a method for forming a corner portion of a water-expandable seal material used therefor.

  In the shield tunnel method, as shown in FIG. 6, the segment 1 as a large number of unitized sealed members is joined in both the direction a of the peripheral wall of the tunnel and the length direction b of the tunnel, A band-shaped sealing material 3 is interposed on the joint surface of the, and exhibits a function of preventing water leakage.

  That is, on the four peripheral edges of the plate surface of each segment 1, there are a ring surface 5 in a direction (direction b of the peripheral wall of the tunnel) perpendicular to the axial direction of the shield tunnel (the length direction a of the tunnel), and the axial direction of the shield tunnel Are formed with piece surfaces 7 in a direction substantially parallel to each other, and adjacent segments 1 are joined to each other at their joining surfaces 5 and 7 by means of connecting bolts (bolt holes 9). When the segment 1 is assembled, the sealing material 3 is attached to each joint surface in order to prevent leakage of spring water from the natural ground into the tunnel.

As for the method of attaching the sealing material 3 to the joining surfaces 5 and 7 of the segment 1, a method called turning pasting in which the belt-like sealing material 3 is pasted to the grooves formed in the joining surfaces 5 and 7 with an adhesive as it is. Alternatively, there is a method in which a fixed sealing material 3 whose length is previously adjusted to the circumferential length of the segment 1 is processed into an annular shape, which is fitted into the segment 1 and attached to the joining surfaces 5 and 7.
When the thickness of the sealing material 3 is relatively small, there is no problem even if the corner portion is not processed. However, as the thickness of the sealing material 3 increases, the sealing material 3 is segmented due to the elasticity of the sealing material 3. As a result, it becomes difficult to make it closely contact with one corner, and the outer corner R of the corner portion of the sealing material 3 becomes large. As a result, the volume of the sealing material 3 is insufficient at the corner portion.

In order to solve the problem in the case where the thickness of the sealing material 3 is relatively large, a method of joining a straight line portion and an L-shaped corner portion along the outer periphery of the segment 1 is used in the past. In recent years, a method of processing the corner portion of the sealing material 3 has been proposed and put into practical use (see Patent Documents 1 and 2).
In Patent Document 1, a slit formed in a predetermined portion of a belt-shaped sealing material is bent at a right angle with the outer side being outside, a prismatic unvulcanized rubber material is filled in the bent portion, and a corner portion is formed by vulcanization press molding. Patent Document 2 discloses that instead of making a cut, it is cut into a V shape and a partially thinned corner portion having an inclined surface is formed by the same molding method as described above. Yes.

Japanese Patent No. 2524308 JP 2001-132394 A

  However, in the tunnel structure in the shield method, the joining form of the ring-like structures formed by joining the segments is usually such that the joining boundary surfaces of adjacent segments constituting the ring-like structure are staggered. For a segment that has been subjected to conventional corner processing, where the joint boundary surface of the adjacent segment that is arranged and constitutes the ring structure and the joint boundary surface of the adjacent ring structure form a T-shaped joint. All the sealing materials corresponded to the tunnel structure in which such a T-shaped joint portion was formed.

  On the other hand, in recent years, in addition to the above-described joint form, the joint boundary surface of the adjacent segment constituting the ring-shaped structure is disposed flush with the ring-shaped structure adjacent to the joint boundary surface of the adjacent segment constituting the ring-shaped structure. There can be seen a joint form in which the joint boundary surface of the body forms a cross-shaped joint.

  In such a joining mode, if a belt-like seal material is attached by turning it around, the volume at the corner becomes insufficient, so it is difficult to stop water under high water pressure conditions. If a sticker is applied, the volume around the corner becomes excessive, which may cause a segment to crack due to the compression reaction force of the sealing material. In addition, when a conventional corner processed product corresponding to high water pressure is used, the volume is excessive at the cross-shaped joint portion, which also adversely affects the segment.

  As described above, the present invention has a water-stopping performance that can withstand high water pressure in view of the current situation that a water-stopping structure suitable for a shield tunnel structure formed with a cross-shaped joint is not known, and The object of the present invention is to provide a waterproof structure for a shield tunnel having a cross-shaped joint portion that does not adversely affect a segment due to excessive volume of the corner portion, and a method for forming a corner portion of a sealing material used therefor.

As a result of earnest research, the present inventors can solve the above problem by processing the corner portion of the sealing material into a square and reducing the outer corner portion of the corner portion to adjust the volume of the corner portion. The present invention has been completed.
That is, the waterproof structure of the shield tunnel according to the present invention is formed by joining a large number of rectangular curved plate-shaped segments, and the adjacent segment joined in the tunnel axial direction with the joint boundary surface of the adjacent segments joined in the tunnel circumferential direction. In the tunnel structure in which the joint boundary surface forms a cross-shaped joint portion, the water stop structure of the shield tunnel is formed by continuously mounting a strip-shaped water-expandable sealing material on the joint surface of each segment, Both the inner and outer corners of the water-swellable sealing material meeting the cruciform joint are processed at a substantially right angle, and at least one of the outer corner ends of the corner is reduced. It is characterized by being.
In addition, the method for forming the corner portion of the water-expandable seal material used in the water blocking structure of the shield tunnel is as follows. A cut or substantially V-shaped cut part is provided in the thickness direction to form a thin-walled hinge part, and the opening part of the cut or cut part formed by bending the seal material body with the thin-walled hinge part as an inner corner side The unvulcanized rubber is filled, and the unvulcanized rubber in the filled portion is vulcanized and molded by a hot press.

  According to the present invention, in the shield tunnel structure in which the cross-shaped joint portion is formed, the volume of the corner portion of the sealing material can be easily adjusted, and the corner portion has a water stopping performance that can withstand high water pressure. It is possible to obtain a waterproof structure for shield tunnels that does not adversely affect the segment due to excessive volume.Since corner processing of the sealing material attached to the segment, the conventional corner processing jig is slightly overlaid. The apparatus and method used for corner processing can be used.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a waterproof structure for a shield tunnel and a method for forming a corner portion of a sealing material according to the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a tunnel structure having a cross-shaped joint portion, FIG. 2 shows the whole sealing material used in the water stop structure according to the present invention, and FIG. 3 shows the outer corner end portion of the corner portion of the sealing material. An example in which both and one of them are thinned is shown, and FIGS. 4 and 5 show a procedure for forming a corner portion of the sealing material.

  As shown in FIG. 1, the water stop structure of the shield tunnel according to the present invention has a cross-shaped joint between the joint boundary surface of the adjacent segment constituting the ring-shaped structure and the joint boundary surface of the adjacent ring-shaped structure. The present invention relates to a tunnel structure to be formed.

  As shown in FIG. 2, the sealing material used in the water blocking structure of the shield tunnel according to the present invention has the inner and outer corners of the corner portion processed at a substantially right angle and the outer corner end portion reduced in thickness. FIG. 3 is a partially enlarged view of a corner portion, (a) shows an example in which both outer corner end portions are thinned, and (b) is an example in which both outer corner end portions are thinned. Show. Although FIG. 3 shows an embodiment in which the shape of the thinned portion is a triangular pyramid shape, the present invention is not limited to the illustrated example and includes other embodiments.

Further, the volume of the reduced thickness portion of the sealing material is preferably about 5 to 25% of the volume of the corner portion. If it is less than 5%, the corner portion tends to be excessive in volume, and if it exceeds 25%, there is a possibility that sufficient water stop pressure cannot be obtained.
In addition, the volume of the above-mentioned corner portion that has been square-processed that serves as a base for the thickness reduction ratio is the volume obtained by adding the reduced thickness to the square corner portion 23 in which the outer corner end portion has been thinned, that is, the inner and outer corners. It refers to the volume of a square columnar corner portion (thickness of the sealing material × thickness × width) assuming that the outer corner end portion has not been thinned, processed at a right angle.

In the present invention, each corner portion of the sealing material that meets the cruciform joint has the same shape at the outer corner ridge line portion, and both outer corner end portions are thinned symmetrically in the width direction of the sealing material. It is preferable from the viewpoint of improving the water stopping performance because the balance is good for supplementing the volume of the corner portion of the sealing material.
Moreover, since the center part of the outer corner of the corner part processed into the square remains without being thinned, there is an effect of increasing the water stop pressure at the meeting portion of each corner part.

  The segment 1 to which the segment sealing material is attached is formed in a rectangular plate shape and has a curved plate surface (refer to FIG. 6), and the axial direction of the shield tunnel at the opposite side position (the length direction b of the tunnel) ) And a pair of ring surfaces 5 in a direction perpendicular to the tunnel wall (direction a of the peripheral wall of the mine shaft), and a joint surface including a piece surface 7 in a direction substantially parallel to the axial direction of the adjacent shield tunnel is formed on the ring surface 5. ing.

The sealing material 21 used for the water blocking structure of the shield tunnel according to the present invention is formed in an endless annular shape along the outer periphery of the segment 1 and has a square corner portion 23 corresponding to each corner of the segment 1. The square corner portion 23 is pasted across the ring surface 5 and the piece surface 7 which are joint surfaces in two directions perpendicular to each other with the protruding corner portion of the segment outer peripheral portion interposed therebetween.
A seal mounting groove is formed on the joint surfaces 5 and 7, and the sealing material 3 is mounted in the groove.

The square corner portion 23 is processed into a square shape at the inner and outer corners, and is thinned at the outer corner.
Therefore, in the water stop structure of the shield tunnel according to the present invention, the shortage of volume at the corner portion of the sealing material is eliminated by the square processing of the corner portion, and the protrusion amount of the rectangular corner portion 23 at the time of fastening the segment is reduced. It is possible to prevent an excessive volume by adjusting the amount of thinning at the outer corner.

  The seal material 21 is made of a water-swellable seal material mainly composed of a rubber substance and a water-swellable resin. As the rubber substance, natural rubber, chloroprene rubber, styrene / butadiene rubber, isoprene rubber, EPDM rubber or the like is used. As the water-swellable resin, polyacrylic acid type, isobutylene / maleic anhydride type, polyurethane type, polyvinyl alcohol type and the like are used. These rubber substances and water-swellable resins can be obtained by mixing appropriate additives such as vulcanizing agents, vulcanization accelerators, inorganic fillers, coloring agents, and softening agents.

  Next, a method for manufacturing the sealing material 21, particularly a method for forming the square corner portion 23, will be described in accordance with the procedure shown in FIG.

  First, the sealing material 21 is formed by extruding a water-swellable sealing material to form a band-shaped sealing material body 25. The water-swellable sealing material is preferably a composite type in which a non-water-swellable rubber layer is used as a base and a water-swellable rubber layer is combined therewith.

  Next, after the sealing material body 25 is vulcanized, it is cut into the circumferential length of the segment 1, that is, the total length of the four joining surfaces of the segment 1, and the obtained standard sealing material body 25 is attached to the segment 1 Then, as shown in FIG. 4A, the thin hinge portions are respectively formed at the four locations corresponding to the respective corners of the segment 1 by cutting in the thickness direction over the entire width of the seal material main body 25.

Next, as shown in FIG. 4B, the sealing material body 25 is bent at a right angle so that the hinge portion is on the inner corner side, and a rectangular column-shaped unvulcanized rubber is formed at an opening formed by opening the cut. Fill.
Thereafter, the filled portion of the unvulcanized rubber is pressed with a heating press machine and heated for a certain period of time in the pressed state and vulcanized to form a square corner with a reduced thickness at the outer corner end as shown in FIG. The part 23 can be molded.

  In FIG. 4, the mode in which the cut made in the thickness direction of the sealing material is opened at a right angle has been described. However, when the outer corner end portion is further reduced in thickness, as shown in FIG. A substantially V-shaped cut portion is provided in the thickness direction over the entire width of the material main body 25 to form a thin hinge portion. Thereafter, as shown in FIG. Bending at a right angle to form an open portion where the V-shaped cut surface is open at an obtuse angle, and filling this with a prismatic unvulcanized rubber, followed by press vulcanization, as shown in FIG. A square corner is formed by thinning the wall.

Both end portions 25a of the sealing material 21 in which the four corner portions 23 are formed are opposed to each other, and a rubber-based curable adhesive is applied and joined.
Rubber-based curable adhesives include rubber components such as chlorinated natural rubber, chloroprene rubber, chlorosulfonated polyethylene, and polybutadiene rubber, low-temperature curing agents such as tetramethylthiuram disulfide and tetramethylthiuram monosulfide, and phenol resins. And a two-component solvent type comprising a curing agent component such as a resole resin or polyisocyanate.

  Thereafter, the bonded portion is heated and cured to obtain an annular sealing material 21 having four square corner portions 23 as shown in FIG.

  In the above-described embodiment, the strip-shaped sealing material body 25 obtained by extrusion molding is cut into the total length of each joint surface of the segment 1, and the four places along each corner of the segment 1 are square. In the above example, the end portions 25a of the sealing material body 25 are joined to form the endless annular sealing material 21. However, the strip-shaped sealing material 21 that is not formed annularly is attached to the joining surface of the segment 1. Moreover, you may join two things which carried out the corner process of the two places of the sealing material main body 25 into a square.

It is explanatory drawing which shows the tunnel structure which has a cross-shaped junction part. It is a front view which shows the whole sealing material used for the water stop structure which concerns on this invention. It is a perspective view which shows the example in which both the outer corner edge parts and one side are thinned in the corner part of a sealing material. It is explanatory drawing which shows the shaping | molding procedure (when making a cut) of the corner part of a sealing material. It is explanatory drawing which shows the shaping | molding procedure (in the case of V-shaped cutting) of the corner part of a sealing material. It is explanatory drawing which shows the conventional tunnel structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Segment 5 ... Ring surface 7 ... Piece surface 21 ... Segment mounting sealing material 23 ... Square corner part 25 ... Sealing material main body

Claims (4)

  A large number of rectangular curved plate-shaped segments are joined, and the joint boundary surface of adjacent segments joined in the circumferential direction of the tunnel and the joint boundary surface of adjacent segments joined in the tunnel axial direction form a cruciform joint. In the tunnel structure, the water-swellable structure of a shield tunnel in which a band-shaped water-swellable sealing material is continuously mounted on the joint surface of each segment, the water-swellable seal meeting the cross-shaped joint part A water stop structure for a shield tunnel, wherein inner and outer corners of a corner portion of the material are both processed at a substantially right angle, and at least one of outer corner end portions of the corner portion is thinned.   The waterproof structure of the shield tunnel according to claim 1, wherein both outer corner end portions of the corner portion are thinned.   The water stop structure for a shield tunnel according to claim 1 or 2, wherein the volume of the reduced thickness portion of the water-expandable sealing material is 5 to 25% of the volume of the corner portion. A thin hinge portion is formed by providing a cut or a substantially V-shaped cut portion in the thickness direction over the entire width of the seal material main body at a predetermined position of a strip-shaped seal material main body made of water-expandable vulcanized rubber. Unsealed rubber is filled in the opening of the cut or cut portion formed by bending the seal material body with the hinge portion as the inner corner side, and the unvulcanized rubber in the filled portion is vulcanized with a hot press machine. The method for forming a corner portion of the water-expandable sealing material used for the water blocking structure of the shield tunnel according to any one of claims 1 to 3.

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