JPH07279596A - Water swelling type annular water sealing member - Google Patents

Abstract

PURPOSE:To improve the water sealing performance by forming an annular water sealing member for sealing the part between a tightening bolt hole on a segment for the tunnel shield execution and a tightening bolt, from the water absorptive polymer compounded ethylene-vinyl acetate copolymer. CONSTITUTION:An ethylene-vinyl acetate copolymer body has a softening temperature of 45 deg.C or below, and a hardness of 80 deg. or less, and an elongation of 700% or more. When this copolymer is used as an annular water sealing member 30, and a nut 25 is tightened, the copolymer is softened by the heat generated at this time, and is used for filling the gap between a hole 11, bolt 20, and a seat metal 26. When the water absorptive polymer such as the sodium acrylate copolymer is compounded with the ethylene vinyl acetate copolymer, the water swelling performance is generated. The gap generated because of the loosening of the nut 25 is filled each time. Accordingly, the water sealing performance can be increased drasticaally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annulus sealing material for sealing between a tightening bolt hole of a tunnel shield construction segment and a tightening bolt inserted into the hole.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 1 and 2, a hole 1 for a tightening bolt of a tunnel shield construction segment 10.
As the ring-shaped waterproofing material 30 for sealing the space between 1 and the tightening bolt 20 inserted into the hole 11 thereof, one made of ethylene vinyl acetate copolymer (EVA) is used. This ring-shaped waterproofing material 30 has a low softening temperature of 40 ° C. and a large elongation of 700%, and the bolt 20 in which it is inserted is inserted into the hole 11 to secure the ring-shaped waterproofing material 30 to the washer 26 and the segment 10. When the nut 25 is tightened by being sandwiched between it and the nut 25, it is softened by the heat generated at that time, stretches, flows into the thread of the bolt 20 as shown in FIG.
The space between the hole 11 and the bolt 20 is sealed by filling the gap between the hole 11 and the bolt 20.

However, the ring-ring water stop material 30 is not particularly defective in a normal case, but when the nut 25 is loosened due to an impact or the like when assembling the segment 10, a gap is generated and water leaks. There is a problem that there is.

[0004]

The problem to be solved is that, in the conventional ring waterproofing material 30 described above, when the nut 25 is loosened, a gap is generated and water may leak.

[0005]

A means for solving the problems will be described with reference to the drawings. The present invention is a ring-shaped waterproof material for sealing between a tightening bolt hole 11 of a tunnel shield construction segment 10 and a tightening bolt 20 inserted into the hole 11, which is made of ethylene vinyl acetate. Water swellability is imparted by blending a water-absorbing polymer into the united body.

[0006]

[Embodiment] Explaining an embodiment, 10 is a segment for tunnel shield construction, and 11 is its segment 10.
A hole for a tightening bolt opened in the hole, 20 is a tightening bolt inserted into the hole 11, 25 is a nut for screwing the bolt 20 to tighten the segment 10, and 26 is a washer for interposing between the nut 25 and the segment 10. Is. Reference numeral 30 is a ring-shaped water blocking material that seals between the hole 11 and the bolt 20 inserted into the hole 11, and is added to 100 parts by weight of the ethylene vinyl acetate copolymer, for example, a sodium acrylate-based polymer or isobutylene anhydrous. Water swellability is imparted by blending 30 to 100 parts by weight of a water absorbing polymer such as a maleic acid copolymer.

Explaining the action, the ethylene vinyl acetate copolymer has a low softening temperature of 45 ° C. or lower, a hardness of 80 ° C. or lower, and a large elongation of 700% or higher.
When this is used as an annulus waterproofing material, it is sandwiched between the washer 26 and the segment 10 and the nut 25 is tightened. When the nut 25 is tightened, it is softened by the heat generated at that time, stretches and flows into the thread of the bolt 20, Filled in the gap between the bolt 20 and the washer 26, it has a function of sealing between the hole 11 and the bolt 20.

Furthermore, by blending the above water-absorbing polymer with an ethylene-vinyl acetate copolymer, water swelling property can be imparted and the water-stopping effect can be remarkably enhanced. The basis is that, in addition to the effect of the conventional ethylene-vinyl acetate copolymer alone, the water-absorbing polymer absorbs water and expands, and for example, the gap caused by the loosening of the nut 25 can be filled each time, and the water-stopping property is further enhanced. There is something that can be done.

[0009]

Since the present invention is constructed as described above,
The water-swelling property of the water-absorbent polymer is added to the sealing effect of the ethylene-vinyl acetate copolymer, whereby the water-stopping property thereof is significantly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an annulus waterproofing material.

FIG. 2 is a cross-sectional view showing a state before tightening the ring waterproofing material of FIG.

FIG. 3 is a cross-sectional view showing a state after fastening the ring waterproofing material of FIG. 1.

[Explanation of symbols]

 10 segment 11 bolt hole 20 bolt 25 nut 26 washer 30 ring ring water stop material

Claims (1)

[Claims] 1. A segment 10 for tunnel shield construction.
In the ring waterproofing material that seals between the tightening bolt hole 11 and the tightening bolt 20 inserted into the hole 11, by mixing the ethylene vinyl acetate copolymer with a water-absorbing polymer, A water-expandable ring-stop water stop material.