JP2006177024A - Segment installing sealant and its processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a segment installing sealant of a shield tunnel, and its processing method, without causing excess and deficiency in the volume of a sealant corner part, by reducing labor and cost required for corner processing, by preventing reduction in sealability, by removing a crack occurrence factor. <P>SOLUTION: This segment installing sealant is formed by connecting a large number of segments formed in a polygonal curved plate shape of a rectangular shape, a trapezoidal shape or a hexagonal shape, and is used for a water cut-off structure of the shield tunnel, and is a water expansive sealant having the thickness of 3 to 8 mm processed in an annular shape to be installed on a contact plane of the segments, and is characterized by processing only a pair of corner parts corresponding to a pair of corners forming a diagonal angle of the segment in a square shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a segment mounting sealing material used for a water blocking structure between joints of segments in a shield tunneling method, and a processing method thereof.

  In the shield tunnel method, as shown in FIG. 5, the segment 1 as a large number of unitized members to be sealed 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 a 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, the conventional segmented seal material for the segment eliminates the volume shortage at the corner, but on the contrary, the volume is excessive, and the segment seal material 3 is compressed by connecting the piece surfaces 7 of the segment 1 to each other. Then, the corner part partially protrudes toward the ring surface 5 side, and when the segment 1 is connected in the axial direction b of the shield tunnel, the protruding part presses the adjacent counterpart segment, and the compression reaction force is applied to the opposing segment. This causes problems such as cracking and a significant decrease in sealing performance.
In addition, the corner machining requires labor and cost, and there is a demand for reduction thereof.

  In view of the above situation, the present invention was made for the purpose of removing the cause of cracking, preventing the deterioration of sealing performance, and reducing the labor and cost required for corner processing. It is an object of the present invention to provide a segment mounting seal material and a processing method therefor without excess or deficiency.

As a result of extensive research, the present inventors have found that the above problem can be solved by processing only one of the opposing corner portions of the sealing material attached to the segment into a square shape, thereby completing the present invention.
That is, the gist of the present invention is a segment mounting sealing material used for a water stop structure of a shield tunnel formed by connecting a large number of segments formed in a rectangular, trapezoidal or hexagonal polygonal curved plate shape,
An annularly processed water-expandable sealing material with a thickness of 3 to 8 mm to be attached to the joint surface of the segment, and only a pair of corner portions corresponding to a pair of corners forming a diagonal of the segment are square. The segment mounting seal material is characterized in that it is processed.
Further, the gist of the present invention is that a predetermined or two portions of a belt-like sealing material body made of water-expandable vulcanized rubber are provided with cuts or substantially V-shaped cut portions in the thickness direction over the entire width of the sealing material body. Forming a thin-walled hinge portion, filling the opening of the cut or cut portion formed by bending the seal material body with the thin-walled hinge portion as an inner corner, and filling the unvulcanized rubber with the unfilled portion of the filling portion. A method of processing a sealing material for segment mounting, characterized in that a vulcanized rubber is vulcanized and molded into a square shape by a heating press, and both end portions of a belt-shaped sealing material are annularly processed with a vulcanizing adhesive. It is in.

  According to the present invention, in order to compensate for the volume shortage of the corner portion of the sealing material attached to the segment, one of the opposing corner portions is processed into a square shape. Projecting toward the processed corner, and filling the voids generated because the unprocessed corner has an R shape can be filled without excess or deficiency in volume. Accordingly, it is possible to effectively prevent the occurrence of cracks in the segment due to excessive volume and the deterioration of the sealing performance due to insufficient volume. In addition, since only the corner portions corresponding to two of the corners of the segment need be processed, the labor and cost required for processing the corner portions can be greatly reduced.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a waterproof structure for a shield tunnel, a seal material for mounting a segment, and a method for processing a corner portion according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing the whole sealing material according to the present invention before being attached to a segment, FIG. 2 is a view showing a corner portion of the sealing material, and FIG. 3 is an overall view showing the same sealing material attached to a segment. FIG. 4 and FIG. 4 are views showing a corner portion of the sealing material when the segments are connected to each other.

  The segment 1 to which the segment sealing material is attached is formed, for example, in a rectangular shape and with a curved plate surface (see FIG. 5), and the axial direction of the shield tunnel at the opposite side position (the length direction of the tunnel) A joint surface is formed of a pair of ring surfaces 5 in a direction perpendicular to b) (direction a of the peripheral wall of the tunnel) and a piece surface 7 in a direction substantially parallel to the axial direction of the adjacent shield tunnel. Has been.

A segment mounting seal material (hereinafter simply referred to as “seal material”) 21 according to the present embodiment is formed in an endless annular shape along the outer periphery of the segment 1, and corresponds to a pair of corners forming the diagonal of the segment 1. A pair of square corner portions 23 are provided. The square corner portion 23 is affixed 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 1 c of the segment outer peripheral portion interposed therebetween.
A sealing material mounting groove 11 is formed on the joint surfaces 5 and 7, and the sealing material 21 is mounted in the groove 11.

  The square corner portion 23 is formed in a rectangular shape at the inner and outer corners, and on the other hand, the corner portion on the side of the adjacent segment facing the square corner portion 23 is not processed into a square shape. Therefore, a gap is generated between the opposite corner portions. However, as shown in FIG. 4, when the segment A and the segment B facing the segment C are fastened, the rectangular corner portion 23 of the sealing material attached to the segment A is The gap generated by the R shape is filled by protruding to the adjacent segment B side.

  Therefore, in the water stop structure of the shield tunnel according to the present invention, the volume shortage at the corner portion of the sealing material is eliminated, and the volume is increased by adjusting the protruding amount of the rectangular corner portion 23 when the segments are fastened. It is possible to prevent.

  As shown in FIGS. 1 and 3, the sealing material 21 used for the water blocking structure of the shield tunnel according to the present invention has a pair of corner portions corresponding to the pair of corners forming the diagonal of the segment 1 as described above. The other pair of corner portions may be left unprocessed as the portion 23.

When the segment 1 is rectangular, the square corner portion 23 is processed so as to exhibit an L-shape that is substantially perpendicular to the inner and outer corners, but the side corresponding to the piece surface 7 of the segment 1 (relative to the unprocessed corner portion). Side) can be slightly increased or decreased to adjust the protruding amount of the square corner portion 23 when the segments are fastened.
When the thickness of the sealing material 21 is relatively small, the square corner portion 23 may be processed at a substantially right angle as shown in FIG. 2A, but when the thickness of the sealing material 21 is relatively large, FIG. As shown in (b), a small protrusion 23a having a substantially triangular cross section is formed on the surface of the corner portion 23 facing the arcuate outer surface of the unprocessed corner portion, which is attached to the adjacent corner portion 23, and is slightly thickened. desirable.

  A material having a thickness of 3 to 8 mm is suitable for the sealing material 21 according to the present invention, and is about 3 to 7 mm when the segment 1 is rectangular. If the thickness is less than 3 mm, a high water stop pressure is not required, so there is no need to process the corner portion. If the thickness is greater than 8 mm, if the corner portion is not processed, go to segment 1. When it is attached, it floats without being in close contact with the segment 1 in the vicinity of the corner portion, which requires an excessive segment fastening force and is not preferable.

  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.
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 combining non-water-swellable rubber.

  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 In this case, a thin hinge portion is formed by providing cuts or substantially V-shaped cut portions in the thickness direction over the entire width of the sealing material body 25 at two locations corresponding to the pair of corners forming the diagonal of the segment 1. To do.

Next, the sealing material body 25 is bent at a right angle so that the hinge portion is located on the inner corner side, and an open portion formed by opening the cut or the cut portion is filled with prismatic unvulcanized rubber.
Then, the corner part 23 can be shape | molded by pressing the filling part of an unvulcanized rubber with a heating press machine, and heating and vulcanizing for a fixed time in a press state.

The two end portions 25a of the sealing material 21 formed with two square corner portions 23 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 two 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 2 corresponding to the diagonal corners of the segment 1. In the above description, an example has been described in which corners are processed into corners and end portions 25a of the sealing material body 25 are joined to form the sealing material 21 in an endless annular shape. It may be mounted on the surface, or two of the sealing material main body 25 that have been processed into a square corner may be joined.

It is a front view which shows the whole sealing material which concerns on this invention. It is a fragmentary figure which shows the corner part of the sealing material which concerns on this invention. It is a front view which shows the state with which the segment of the sealing material which concerns on this invention was mounted | worn. It is explanatory drawing which shows the corner part of the sealing material when segments are connected. It is explanatory drawing which shows the assembly structure of the segment which mounted | wore with the sealing material in a shield tunnel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Segment 5 ... Ring surface 7 ... Piece surface 11 ... Sealing material installation groove | channel 21 ... Segment mounting sealing material 23 ... Square corner part 25 ... Sealing material main body

Claims (4)

In the sealing material for mounting a segment used in the water stop structure of a shield tunnel formed by connecting a large number of segments formed in a rectangular, trapezoidal or hexagonal polygonal curved plate shape,
An annularly processed water-expandable sealing material with a thickness of 3 to 8 mm to be attached to the joint surface of the segment, and only a pair of corner portions corresponding to a pair of corners forming a diagonal of the segment are square. A sealing material for mounting a segment, characterized by being processed into. A shield tunnel formed by connecting a large number of segments having a pair of ring surfaces forming a junction surface in the tunnel axis direction and a pair of piece surfaces forming a tunnel circumferential direction junction surface. In the segment mounting seal material used for water structures,
An annularly processed water-expandable sealing material having a thickness of 3 to 7 mm, which is attached to a pair of ring surfaces and a pair of piece surfaces of the segment, and corresponds to a pair of corners forming a diagonal of the segment A segment mounting sealing material, wherein only a pair of corners are processed into a square shape.   The segment mounting according to claim 1 or 2, wherein a small protrusion having a substantially triangular cross section is formed on a surface opposite to the arcuate outer surface of the unprocessed corner portion pasted around the corner portion processed into a square shape. Sealing material. A thin hinge part is formed by providing a cut or a substantially V-shaped cut portion in a thickness direction in two predetermined portions of a band-shaped sealing material body made of water-expandable vulcanized rubber over the entire width of the sealing material body, Unsealed rubber is filled into the opening portion of the cut or cut portion formed by bending the seal material body with the thin hinge portion as the inner corner side, and the unvulcanized rubber in the filled portion is heated with a hot press. The segment mounting sealing material according to any one of claims 1 to 3, wherein the segment mounting sealing material according to any one of claims 1 to 3, wherein the both ends of the belt-shaped sealing material are annularly processed with a vulcanizing adhesive. Processing method.

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