JP3459288B2 - Water expansion composite sealing material for segment joints - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal material for a segment joint portion used in a shield construction method.

[0002]

2. Description of the Related Art A combination of water-expandable rubber and non-expandable rubber has been proposed as a seal material for a segment joint used in a conventional shield construction method. For example, in Japanese Utility Model Laid-Open No. 4-89198, as shown in the cross-sectional view of FIG. 9, a water-expandable rubber layer 1 and a non-expandable rubber layer 2 are continuously laminated along the longitudinal direction to form a strip plate shape. The non-expansion portion is partially exposed continuously on the sticking surface 4 of the sealing material in the lengthwise direction, and the expansion portion is on both side portions 4a and the sticking surface 4 of the sticking surface 4 of the non-expanding portion. It is arranged to consist of adjacent side surfaces and opposite surfaces.

Further, in Japanese Patent Laid-Open No. 5-1275, FIG.
As shown in (a), a composite seal material has been proposed in which a water-expandable rubber layer 1 is formed around a non-expandable core material 3 and integrated.

In addition to this, as shown in FIG. 11 (a), the water-swellable rubber layer 1 and the non-swellable rubber layer 2 are simply laminated in two or more layers only with different thicknesses. Things have been proposed.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the case of No. 198 (FIG. 9), the expansion pressure of the water-expandable rubber layer 1 escapes in the width direction of the sealing material, so that not only a large sealing effect cannot be expected, but also the expansion pressure causes the sealing surface to stick to the surface. It also expands in four directions and peels off the non-expandable rubber layer 2 from the sticking surface 4. Further, since all the sticking surfaces 4 are not the non-expandable rubber layer 2, the adhesiveness is poor and, as a result, the sealing property is also poor.

Further, Japanese Patent Application Laid-Open No. 5-1275 (see FIG. 10)
In the case of (a), since the entire surface of the sealing material is surrounded by the water-expandable rubber, the sealing material cannot be bonded to the sealing surface. Further, the expansion pressure of the water-expandable rubber acts in each radial direction of the sealing material as shown in FIG. 10B, but also acts in the width direction, resulting in escape in the width direction, and a large sealing effect is expected. Can not.

Further, a simple laminated sealing material (see FIG. 11) is used.
In (a), the expansion pressure of the water-expandable rubber is shown in FIG.
As shown in Fig. 3, not only the sealing material escapes in the width direction, and as a result, a large sealing effect cannot be expected, but the non-expandable rubber layer 2 bends as the water-expandable rubber layer 1 expands in the width direction. May peel off from the adhesive surface.

An object of the present invention is to solve the above-mentioned problems and to provide a sealing material which can easily exhibit a large sealing effect.

[0009]

In order to solve the above-mentioned problems, the water-expansion composite seal material according to claim 1 is a seal material for sealing a joint portion of a segment used in a shield construction method, in which it comes into contact with water. Of a non-expandable rubber layer that hardly expands and a water-expandable rubber layer that expands when contacted with water are laminated, and the non-expandable rubber layer and the water-expandable rubber layer are formed. The cross-sectional area ratio is in the range of 95: 5 to 20:80, and the water-swellable rubber layer and the non-swellable rubber layer each have a plurality of grooves or holes extending in the longitudinal direction. The cross-sectional area of the water-expandable composite seal material excluding the grooves or holes is 0.8 to 1.3 times the cross-sectional area of the seal groove pre-processed in the joint portion of the segment as 1 . Claim 2
The invention described is a sealing material for sealing a joint portion of a segment used in a shield construction method, in which a non-expandable rubber layer that hardly expands even when contacted with water and a water-expandable rubber layer that expands when contacted with water are laminated. And a cross-sectional area ratio of the non-expandable rubber layer to the water-expandable rubber layer is in the range of 95: 5 to 20:80, and the non-expandable rubber layer is Has a plurality of grooves or holes extending in the longitudinal direction, and the cross-sectional area of the water-expandable composite seal material excluding the grooves or holes is equal to the cross-sectional area of the seal groove preprocessed in the joint portion of the segment. 0.8 as 1
To 1.3 times. The invention according to claim 3 is characterized in that the cross-sectional shape of the water-expandable composite seal material is symmetrical with respect to a plane of symmetry that passes through the center line and is perpendicular to the laminated surface. The invention according to claim 4 is characterized in that the number of the grooves or holes is plural, and the grooves or holes are not provided on the vertical symmetry plane. In the invention according to claim 5, the distance from the symmetry plane to the closest groove or hole, or the distance between the grooves or holes is 10% or more (excluding 100% or more) of the maximum width of the sealing material. It is characterized by The invention according to claim 6 is characterized in that the cross-sectional shape of the water-expandable composite sealing material has four or more sides. The invention according to claim 7 is characterized in that the exposed surface of the water-swellable rubber layer is one surface, and the other surface is embedded in contact with the non-swellable rubber layer.

[0010]

[0011]

[0012]

As described above, since the surface other than the exposed surface of the water-swellable rubber layer 1 is surrounded by the non-swellable rubber layer 2,
The expansion pressure upon contact with water acts only on the exposed surface that is not surrounded by the non-expandable rubber layer 2, and the pressing effect acts effectively.

Further, when the expansion pressure is too strong, the holes 5 and the like serve as escape areas for extra pressing force and prevent breakage of the segments and the like.

[0014]

1 is a cross-sectional view of an example of a water-expandable composite sealing material of the present invention. This composite sealing material has a rectangular cross section and has water-expandable rubber layers 1 each having holes 5a on both ends of one long side, and three sides of the water-expandable rubber layer 1 (one length on the hole 5a side). Side surfaces project in a triangular shape so as to surround (including sides), and a non-expandable rubber layer 2 having grooves 5b formed on both ends of the lower surface (the surface opposite to the water-expandable rubber layer 1). The total thickness is, for example, about 12 mm.

The above-described water-expandable composite sealing material is applied to the segment 7
When inserting in between, as shown in FIG. 2A, first, the seal groove 7a is opposed to the seal groove 7a of the other segment 7,
As shown in FIG. 2B, a water-expandable composite seal material is inserted into each seal groove 7a so that the water-expandable rubber layer 1 faces each other, and the segments 7 are connected to each other with an opening of 3 mm or less. To do.

In the cross section of the water-expandable composite sealing material described above, the ratio of the cross-sectional areas of the non-expandable rubber layer 2 and the water-expandable rubber layer 1 is 95.
Pairs 5 to 20:80. This is because if the water-swellable rubber layer 1 is 5% or less, a sufficient expansion pressure cannot be secured. Also, 80
% Or more is too much and expands in the width direction so that the non-expandable rubber layer 2
It is impossible to maintain the sealing property for a long time. Considering these conditions, the optimum cross-sectional area ratio is 95: 5 to 50:50.

The cross-sectional area of the water-expandable composite sealing material excluding the holes 5 is 0.8 to 1. When the cross-sectional area of the seal groove 7a previously processed in the joint portion of the segment 7 is 1. 3 times. If it is 0.8 times or less, the cross-sectional area of the sealing material is too small and the sealing property is not obtained. On the other hand, when the ratio is 1.3 times or more, the cross-sectional area (volume) of the sealing material is excessive, the compressive stress of the sealing material becomes larger than the compressive strength of the segment, and the segment is broken or cracked. Then, the excessive sealing material overflows between the segments and expands the openings between the segments. From this, the optimum cross-sectional area of the sealing material is 0.9 to 1.1.

Although a plurality of holes 5 extending in the longitudinal direction are formed, the sealing material is usually required to have a sealing property even when the openings are 0 mm and when the openings are open. For this reason, the seal material used is narrower than the width of the seal groove of the segment and thicker than the depth of the seal groove. In the conventional example of FIG. 12, the thickness of the sealing material becomes thicker, the width thereof becomes narrower, and it becomes unstable when compressed (when the segment is assembled), and the sealing property is deteriorated (FIG. 13A). (See (b)). It is especially unstable when misalignment (shift between left and right) occurs in the segments.

For the non-expandable rubber layer 2 described above, for example, natural rubber, chloroprene rubber, butadiene rubber or the like is used. It is a usual rubber compound obtained by adding a vulcanizing agent, a vulcanization accelerator, a plasticizer or, if necessary, an anti-aging agent and a filler to these vulcanizable rubbers, and has an appropriate tackiness and plasticity ( (Blocking property) is retained.

The above-mentioned vulcanizing agent, vulcanization accelerator, plasticizer, antiaging agent, filler and the like may be any known ones used in ordinary rubber compounds. Specifically, sulfur, magnesium oxide, etc. are used as the vulcanizing agent, thiazole, imidazole, etc. are used as the vulcanization accelerator, and stibulin, process oil, dibutyl phthalate, etc. are used as the plasticizer.

Further, amine, phenol and the like are used as the antiaging agent, and calcium carbonate, magnesium oxide, carbon black, hard clay, zinc white and the like are used as the filler. In addition to these, rosin, coumarone, indene and the like can be used as a tackifier.

The water-swellable rubber layer 1 is obtained by kneading a water-swellable resin (water-absorbent resin) in the above rubber,
Specific examples of the water-swellable resin include water-swellable urethane resin, water-swellable polyvinyl alcohol, water-swellable acrylic resin, water-swellable polyethylene oxide, starch and cellulose.

Experimental Example 1) Chloroprene rubber as a component of the non-expandable rubber layer 2 100 parts by weight Magnesium oxide 5 parts by weight Activated zinc white 5 parts by weight Vulcanization accelerator 1 part by weight Stearic acid 1 part by weight Antioxidant 2 parts by weight Process oil 10 parts by weight Carbon black 40 parts by weight Calcium carbonate 25 parts by weight 2) 50 parts by weight of a water-swellable resin polyacrylic acid sodium polymer is mixed with a known rubber as a component of the water-swellable rubber layer 1, and the mixture is rolled. It was kneaded in. 3) These non-expandable rubber and water-expandable rubber are extruded by a two-layer extruder to form a two-layer structure. At this time, the hole 5a and the groove 5b are formed by processing a die of an extruder. This sealing material is wound up and placed in a vulcanization can (vulcanization kettle) at a vulcanization temperature of 120.
Vulcanization is performed at a temperature of 2 ° C. for 2 hours to produce a sealing material. Instead of the vulcanizing can, it may be carried out by passing through an atmosphere at a vulcanization temperature, and the non-expandable rubber and the water-expandable rubber cannot be adhered to each other only by vulcanization after adhesion. In this case, each may be vulcanized and then bonded with an adhesive. 4) A water expansion and water pressure resistance test was conducted using this sealing material and a conventional two-layer structure sealing material as a comparative example. In addition, in consideration of durability, the magnification of the sealing material was 2 to 4 times that of the sealing material.

In the water expansion test, as shown in FIGS. 4 and 5, (a) is the state before expansion of the water-expandable rubber layer 1,
(B) is a state after absorbing water and expanding, and in the case of the present invention of FIG. 4, since the three inner surfaces of the water-expandable rubber layer 1 are pressed by the non-expandable rubber layer 2, expansion in only one direction Therefore, a large pressing force can be obtained.

In the conventional example of FIG. 5, since the water-swellable rubber layer 1 expands in three directions except for the surface adhered to the non-swellable rubber layer 2, the non-swellable rubber layer 2 is curved. Not only is the pressing force dispersed, but the pressing force that escapes to the left and right is greater than the pressing force that disperses the pressing force against the other party, and it is difficult to obtain the required pressing force.

As shown in FIGS. 6, 7 and 8, the water pressure resistance test was conducted for 30 days at room temperature with the test segment 6 having an opening of 3 mm and a misalignment of 3 mm. This water pressure resistance test apparatus is shown in FIG. 8, and (a) is an explanatory view of the test circuit,
(B) is a cross-sectional view of the test segment, (C) is a top view (half only), and the test results are shown in Table 1.

[0027]

[Table 1]

FIG. 3 is a sectional view of each embodiment having another shape.
(A) is a water-expandable rubber layer 1 having a rectangular shape and a downward trapezoidal shape as a whole.
And a water-swellable rubber layer 1 and a non-swellable rubber layer 2 are formed.
A hole 5a having a center is provided on the joint surface with.
(B) is a deformed hexagon in which the upper and lower ends of the rectangle are cut diagonally, and the rectangular water-swellable rubber layer 1 is inserted in the upper surface so as to be surrounded by the non-swellable rubber layer 2. Two holes 5 for each of the expansive rubber layer 1 and the non-expandable rubber layer 2
a is provided.

In FIG. 3C, the overall shape is a trapezoid, and a rectangular water-expandable rubber layer 1 is inserted from the upper side to the inside so as to be surrounded by the non-expandable rubber layer 2. Two
The two grooves 5b are provided only on the lower surface (bottom of the trapezoid). In (d), the overall shape is the same as in FIG. 1, but the water-swellable rubber layer 1 does not have the holes 5a, and instead, grooves 5b are provided on both sides of the upper surface (front surface).

3 (e) has the same overall shape as that of FIG. 1, but the contact surface between the water-swellable rubber layer 1 and the non-swellable rubber layer 2 is one curved surface. Although the whole shape of (f) is the same as that of FIG. 1, the cross-sectional shape of the water-swellable rubber layer 1 is a triangle, and two sides thereof are in contact with the non-swellable rubber layer 2.

Since the operation and effect of each of these embodiments are the same as those in the case of FIG. 1, detailed description thereof will be omitted.

[0032]

By using the sealing material of the present invention,
Even if there is a leak, opening, or misalignment between the segments,
The expansion force of the sealing material does not escape in the width direction, and high sealing performance can be maintained for a long period of time.

Since the sealing material has a shape that conforms to the sealing groove of the segment, it has a wide and stable shape even when subjected to compression due to the assembly of the segment, so that the sealing material can be uniformly arranged and compressed. And can easily maintain high sealing performance.

[Brief description of drawings]

FIG. 1 is a sectional view of an example of a water-expandable composite sealing material of the present invention.

FIG. 2 is a sectional view of a seal portion of a segment, (a) is a sectional view of a seal groove portion of a segment, and (b) is a sectional view in a state where a water-expandable composite seal material is inserted.

FIG. 3 is a cross-sectional view of a water-expandable composite sealing material of another example of the present invention, in which (a) has a rectangular outer shape, and (b) is a modified hexagonal shape in which both corners are obliquely removed on the upper surface. Things, (C)
1 has a trapezoidal outer shape, (d) has the same outer shape as FIG. 1, but has all grooves, and (e) has the same outer shape as FIG. 1, but has a water-expandable rubber layer and a non-expandable rubber layer. The contact surface with is one curved surface, (f) has the same outer shape as in FIG. 1, but the cross-sectional shape of the water-swellable rubber layer is a triangle, and two sides of which are non-swellable rubber layers. It is in contact.

FIG. 4 is a state diagram before and after water expansion of the water-expansion composite seal material of the present invention, (a) before expansion, and (b) after expansion.

FIG. 5 is a state diagram of a conventional water-expandable composite seal material before and after water expansion, in which (a) is before expansion and (b) is after expansion.

FIG. 6 is a state diagram immediately before the water pressure resistance test of the water-expandable composite sealing material of the present invention.

FIG. 7 is a state diagram of a conventional water-expandable composite sealing material immediately before a water pressure resistance test is performed.

FIG. 8 is an explanatory view of a water pressure resistance test apparatus, (a) is an explanatory view of a test circuit, (b) is a sectional view of a test segment, and (c).
Is also a top view (half only).

FIG. 9 is a cross-sectional view of an example of a conventional water-expandable composite sealing material.

FIG. 10 is a cross-sectional view of another example of a conventional water-expandable composite sealing material, where (A) is a cross-sectional view before expansion and (B) is a cross-sectional view after expansion.

FIG. 11 is a cross-sectional view of still another example of a conventional water-expandable composite sealing material, (A) is a cross-sectional view before expansion, and (B) is a cross-sectional view after expansion.

FIG. 12 is a state diagram before inserting segments according to a conventional example of inserting a seal.

13A and 13B show a state of inserting a seal according to a conventional example, FIG. 13A is a state diagram of FIG. 12, and FIG.

[Explanation of symbols]

1 Water-swellable rubber layer 2 Non-expandable rubber layer 3 Non-expandable core material 4 Attached surface 5 holes, etc. 5a hole 5b groove

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yukio Sato               1456 Asama-cho, Hachioji-shi, Tokyo Su Co., Ltd.               In Rebond (72) Inventor Yutaka Kobayashi               1456 Asama-cho, Hachioji-shi, Tokyo Su Co., Ltd.               In Rebond                (56) References JP-A-4-60098 (JP, A)                 Actual Kaihei 3-111699 (JP, U)                 Actual Kaihei 4-89198 (JP, U)

Claims (7)

(57) [Claims] 1. A sealing material for sealing a joint portion of a segment used in a shield construction method, comprising a non-expandable rubber layer which hardly expands even when contacted with water, and a water-expandable rubber layer which expands when contacted with water. And a cross-sectional area ratio of the non-expandable rubber layer to the water-expandable rubber layer is in the range of 95: 5 to 20:80, and the water-expandable rubber layer is And a plurality of grooves or holes extending in the longitudinal direction are respectively formed in the non-expandable rubber layer,
Furthermore, the cross-sectional area of the water-expandable composite seal material excluding the grooves or holes is 0.8 to 1.3 times the cross-sectional area of the seal groove preprocessed in the joint portion of the segment as 1 to 1. Water-expansion composite seal material for the segment joint part. 2. A sealing material for sealing a joint portion of a segment used in a shield construction method, comprising a non-expandable rubber layer which hardly expands even when contacted with water, and a water-expandable rubber layer which expands when contacted with water. And a cross-sectional area ratio of the non-expandable rubber layer to the water-expandable rubber layer is in the range of 95: 5 to 20:80, and the non-expandable rubber layer is Has a plurality of grooves or holes extending in the longitudinal direction, and the cross-sectional area of the water-expandable composite seal material excluding the grooves or holes is equal to the cross-sectional area of the seal groove preprocessed in the joint portion of the segment. 0.8 as 1
To 1.3 times the water-expansion composite seal material for the segment joint portion. 3. The water-expansion composite seal material according to claim 1, wherein the cross-sectional shape of the water-expansion composite seal material is a shape that is symmetric with respect to a symmetry plane that passes through a center line and is perpendicular to the laminated surface. 4. The water-expansion composite sealing material according to claim 1, wherein the groove or hole is plural in number and is not provided on the vertical plane of symmetry. 5. The distance from the symmetry plane to the closest groove or hole, or the distance between the grooves or holes is 10% or more (excluding 100% or more) of the maximum width of the sealing material. 2 or 4 water-expandable composite sealing material. 6. The cross-sectional shape of the water-expandable composite sealing material is 4
The water-expandable composite sealing material according to claim 1, which has the above-mentioned sides. 7. The water-expandable composite seal according to claim 1, wherein the exposed surface of the water-expandable rubber layer is one surface, and the other surface is embedded in contact with the non-expandable rubber layer. Material.