JP2832799B2 - Water stopping method of segment and grout cap or segment subjected to water stopping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stopping water leaking from a grout injection hole of a segment due to spring water from the ground after construction in a shield work for injecting grout material, and a method for use in the water stop treatment. Segment having a grout cap or grout injection hole.

[0002]

2. Description of the Related Art In order to prevent water leakage from a grout hole in a shield work for grout injection, a method of winding a seal tape around a grout cap and screwing the grout into the grout injection hole to stop water is usually performed.

A method of filling a space of a grout injection hole with a solid or semi-solid filler and stopping water is disclosed in Japanese Patent Laid-Open No. 4-17 / 1990.
4193. JP-A-52-151217
Also, Japanese Patent Application Laid-Open No. 53-132146 discloses a technique of attaching a rubber packing to a seating surface of a grout cap.

Further, as a method of fixing and sealing a screwed member, a technique of pre-coating a screwed portion with a sealing material containing a water-swellable resin is disclosed.

[0005]

In the shield construction where grout material is injected, if there is water leakage from the segment due to spring water from the ground, the secondary work of the segment will be performed after the water is stopped again. This causes the construction period to be delayed.

[0006] As a method of preventing water leakage from between the joint surfaces of the segments, a method of attaching a butyl rubber-like tape water-stop material around the segments is usually adopted. The method described above is applied as the water stoppage treatment for preventing water leakage from the grout cap of the grout injection hole.

However, the above-mentioned method of filling a grout injection hole with a solid or semi-solid filler has a high water-stopping effect, but has a disadvantage that the construction cost is high and the construction period is prolonged.

When a rubber packing is attached to the above-mentioned grout cap, the rubber packing must be sufficiently compressed in order to obtain a water stopping effect. for that purpose,
It is necessary to tighten the grout cap with high torque. However, depending on the work environment at the construction site, it may be difficult to tighten the grout cap with high torque, and due to individual differences between workers at the site, the grout cap may not be fully tightened until the water stopping effect is obtained. , Causing water leakage after construction.

In addition, the method of winding the seal tape around the grout cap has the advantage that the seal tape has lubricity and the water stopping effect can be obtained with the above-mentioned high torque without tightening the grout cap.

However, in the shield construction for grout injection, a grout cap is screwed in immediately after grout material injection to seal the grout injection hole. Then, in order to confirm whether or not the grout material has been cured, it is necessary to remove the grout cap again and inspect the cured state from the grout injection hole. In this case, since the removed sealing tape of the grout cap is plastic and has no restoring force, it does not return to the original shape while being deformed to the shape of the screwing surface at the time of tightening. Therefore, the grout cap removed for inspection has the disadvantage that the first seal tape must be peeled off before reuse and a new seal tape must be wound before use.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a method for preventing water from leaking from a grout injection hole and a grout cap or segment used in the method, which has improved the above-mentioned disadvantages of the prior art.

[0012] In the method of the present invention, the coating material is provided on at least one of the threaded portion of the grout injection hole for injecting the grout material or the threaded portion of the grout cap in the concrete segment or the steel segment of the shield method. A water-blocking material composition prepared by mixing and dispersing a water-absorbing swellable resin in advance to form a dry coating film, and after injecting the grout material, screwing the grout cap into the grout cap to screw in the segment from the grout injection hole. It is a method to stop water leakage.

[0013] The grout cap of the present invention used in the above-described water stopping process has a coefficient of expansion of 3 to 1 at the time of water absorption in the threaded portion.
It is characterized in that a dried film of the water-stopping material composition having a volume of 0 times is formed in advance. Furthermore, a water-absorbing swellable resin is used in which a water-absorbing swelling amount of the water-stopping material composition is 3 to 10 times that of a coating material obtained by dispersing a fluorine resin in an acrylic resin solution. Characterized in that a water-stopping material composition obtained by mixing and dispersing is used.

[0014] The segment of the present invention used in the above-mentioned water-stopping method is characterized in that the water-absorbing material composition has an amount of water-absorbing material having an expansion coefficient of 3 to 10 times at the threaded portion of the grout injection hole. This is a segment characterized by forming a dry coating film of a water-stopping material composition in which a water-swellable resin is mixed and dispersed.

Further, the present invention provides a grout cap or segment, wherein a water-repellent thin film made of wax or oil is provided on the surface of the dried coating film of the water-blocking material composition treated on the screwed portion. About.

The water-swellable resin used in the present invention may be any resin that can absorb water and swell when it comes into contact with water to maintain a non-flowable state. This is one in which a slight cross-linking is introduced.

Examples include starch-acrylonitrile graft polymer hydrolyzate and starch-based starch.
Such as acrylic acid graft polymer, cellulose-acrylonitrile graft polymer and carboxymethylcellulose cross-linked cellulose, polysaccharide-based hyaluronic acid and agarose, and natural water-swellable resin such as protein-based collagen resin. .

In addition, crosslinked polyvinyl alcohol, crosslinked sodium polyacrylate, crosslinked sodium acrylate-vinyl alcohol, crosslinked polyethylene glycol diacrylate, maleic anhydride copolymer, polyvinylpyrrolidone copolymer And other synthetic resin-based water-swellable resins.

The coefficient of expansion of the water-blocking material composition due to water absorption is 3-1.
0 times is preferred. If the expansion rate is 3 times or less, the sealing performance at the threaded surface of the grout injection hole is reduced. When the expansion rate is 10 times or more, the water resistance of the dried coating film decreases, and the sealing durability of the screwed surface decreases. Preferably, when the expansion rate is about 7 times, the effect is obtained that the sealing performance and durability on the threaded surface are excellent, and the grout cap is removed, and then the grout cap can be used again as it is, and the reusability is excellent. .

In order to make the above-mentioned expansion coefficient 3 to 10 times, the water-absorbing swellable resin is added and dispersed in 3 to 20% by weight based on the solid content of the coating material to prepare a water-stopping material composition. I do. However, since the expansion coefficient differs depending on the type of the water-swellable resin, the amount of the water-swellable resin must be arbitrarily changed according to a predetermined expansion coefficient.

The coating material, which is the other component of the water-stopping material composition used in the present invention, includes acrylic resin, vinyl acetate resin, vinyl acetate ethylene resin, nylon resin,
A resin arbitrarily selected from epoxy resin, phenolic resin, styrene resin, ester resin, urethane resin, polyolefin resin, vinyl chloride resin, butadiene rubber, isoprene rubber, chloroprene rubber, acrylonitrile rubber, acrylic rubber, polysulfide polychlorinated rubber, etc. Inorganic fillers such as calcium carbonate, silica, alumina, titanium oxide, iron oxide, lime, talc, clay, carbon, etc. are added to resin solutions in which elastomers, rubbers, etc. are dissolved in organic solvents, or emulsions, latexes, etc. do it,
Any composition that can form a coating film on the screwed portion may be used.

Further, when the grout cap is screwed into the grout injection hole, a fluororesin or graphite is added to the above-mentioned coating material in order to reduce the frictional force of the coating film of the water-stopping material composition and reduce the tightening torque. It is preferable to add a solid lubricating substance such as molybdenum disulfide or the like.

As a particularly preferred coating material of the present invention, a composition containing a titanium oxide as an inorganic filler and a Teflon resin powder dispersed in a toluene solution of an acrylic resin, and further containing a surfactant for assisting dispersion of the water-absorbing swellable resin is exemplified. Can be This is because in the case of this composition, properties such as sealability, durability, reusability, lubricity and the like are excellent.

As a method for forming a dry coating film of the water-stopping material composition on the threaded portion of the grout cap or grout injection hole of the present invention, application by brush coating, spray coating, dipping, roll transfer, etc., and then drying or Baking to form a coating film of the water-stopping material composition. Further, a coating film can also be formed by heating the screwed portion in advance and spray-coating and fusing the water-stopping material composition.

Since the dried coating film of the above-mentioned waterproofing material composition expands when it comes into contact with water, it is necessary to prevent the segments and the grout cap from being wetted by rainwater or stored in a high humidity environment at the distribution stage. In addition, if the coating film expands by contact with water before use, the torque at the time of tightening the grout cap increases. Therefore, the present invention imparts water repellency to the surface by spraying wax or oil onto the coating film of the water-stopping material composition to form a thin film. The wax or oil coating not only prevents the contact of the coating with water, but also provides lubricity in tightening the grout cap and reduces the tightening torque. In addition, since this film is a trace component as a component of the water-stopping material composition, it does not hinder water absorption expansion at the screwing surface after the grout cap is screwed in. There is no adverse effect.

Therefore, the water stopping method of the present invention comprises forming a coating film of a water stopping material composition which expands upon absorbing water in advance on at least one of the screwed portions of the grout cap or the grout injection hole, and forming the segment. After assembling and constructing a tunnel wall and injecting the grout material into the ground from the grout injection hole of the segment, simply screwing the grout cap into the grout injection hole can stop water leakage from the grout injection hole.

[0025]

According to the present invention, a coating film of the water-stopping material composition is formed on the screwing surface of the grout injection hole and the grout cap, which expands three to ten times when water is absorbed. Even if the spring water permeates into the threaded surface of the grout cap, the coating film of the water-stopping material composition expands to enhance the water-stopping effect.

Further, since a dry coating film of the water-stopping material composition has already been formed in advance on the threaded portion of the grout cap or the grout injection hole, the water stopping process can be easily performed even in a work place such as a tunnel.

Further, by forming a thin film of wax or oil on the coating film of the water stopping agent composition,
The expansion of the grout cap or segment can be prolonged by preventing swelling due to contact with water at the distribution stage.

[0028]

EXAMPLES The effects of the present invention will be described with reference to the waterproofing compositions shown in Table 1 below.

[0029]

[Table 1]

Example 1, Comparative Example 3 No. 1 and Comparative Composition No. 1 3 was applied to a PT2 tapered screw grout cap and dried by heating to obtain a grout cap having a coating film formed on the screwed portion. Tighten the grout cap to a PS2 tapered female thread pipe to which no water blocking agent composition has been applied.
By screwing in with gf · m, a test piece for a pressure test was obtained.
The water stopping agent composition No. A test piece with a grout cap coated with No. 1 was used as Example 1 and a comparative composition N
o. The test piece to which the grout cap of No. 3 was assembled is referred to as Comparative Example 3.

Example 2, Comparative Example 4 2 and Comparative Composition No. 2 4 for PS2
Was applied to a pipe having a tapered female thread, and dried by heating to obtain a pipe having a coating film formed on a threaded portion. A grout cap on which the water-stopping agent composition was not applied was screwed into the pipe with a tightening torque of 5 kgfm to obtain a test piece for a pressure test. The water stopping agent composition No. The test piece in which the pipe coated with No. 2 was assembled was referred to as Example 2, and Comparative Composition No. 2 was used. 4
The test piece in which the pipe was assembled is referred to as Comparative Example 4.

Pressure resistance test 5 kgf / cm
An air leak from the threaded portion due to a change with time when the air pressure of No. ² was applied was confirmed. Table 2 shows the number of test pieces that have undergone air leak due to a change with time in the pressure resistance.

[0032]

[Table 2]

Reusability test In the same manner as in the above-mentioned pressure resistance test, air pressure of 5 kg was applied to the test piece.
After leaving in water for 24 hours while applying f / cm ² ,
The threaded portion of the pipe and grout cap was opened. Then tighten the pipe and grout cap with a torque of 5
The screw was again screwed in at kgfm to perform a pressure test of immersion in water for 24 hours in the same manner as described above. Table 3 shows the number of test pieces that leaked air up to 5 cycles when the operation of opening and retightening the pipe and grout cap was one cycle.

[0033]

[Table 3]

[0034]

According to the present invention, since the coating film of the water-blocking agent composition containing the water-absorbing and swellable resin component is formed in the grout injection hole or the threaded portion of the grout cap, the grout cap is screwed into the grout injection hole. Even if the spring water from the ground penetrates into the segment only by doing so, the coating film of the water-stopping agent composition swells at the threaded portion and water leakage from the grout injection hole can be stopped. In addition, since the coating of the water-blocking agent composition including the solid lubricant is formed in advance on the grout injection hole or the threaded portion of the grout cap, the grout cap is easily screwed in at the site of the shield construction. With this, a water stopping effect can be obtained.

Furthermore, since a thin water-repellent film is formed on the surface of the coating film of the water-stopping agent composition of the present invention with wax or oil, the grout cap or segment becomes wet with water during the distribution stage or the storage stage. Even so, the water absorption and swelling of the coating film can be prevented, the life of the product can be maintained long, and the screwing can be easily performed.

Claims (6)

(57) [Claims] In a concrete segment or a steel segment of a shield method, at least one of a threaded portion of a grout injection hole or a threaded portion of a grout cap for injecting a grout material is mixed and dispersed with a water-absorbing swellable resin in a coating material. A method in which a water-stopping material composition is applied in advance to form a dry coating film, and after the grouting material is injected, the grout cap is screwed in to prevent water leakage from a grout injection hole of a segment. 2. The water stopping process according to claim 1, wherein the expansion coefficient of the screwed portion of the grout cap at the time of absorbing water is 3 to 3.
A grout cap, wherein a dried coating film of the water-stopping material composition which is ten times larger is formed. 3. The water-stopping material composition according to claim 2, wherein the water-stopping material composition has a swelling coefficient of 3 to 1 in a coating material obtained by dispersing a fluorine resin in a solution of an acrylic resin.
A grout cap, wherein a dry coating film of a water-blocking material composition in which a water-absorbing swellable resin is dispersed in an amount of 0 times is formed on a screwed portion. 4. The water-stopping method according to claim 1, wherein the expansion rate of the water-stopping material composition at the threaded portion of the segment grout injection hole is 3 to 10 times the water-absorption swelling. A segment characterized in that a dry coating film of a water-stopping material composition in which a water-soluble resin is dispersed in a coating material is formed in advance. 5. The grout cap according to claim 2,
A grout cap, wherein a water-repellent thin film made of wax or oil is provided on a dried coating film of a water-blocking material composition. 6. The segment according to claim 4, wherein
A segment, wherein a water-repellent thin film made of wax or oil is provided on a dried coating film of a water-blocking material composition formed on a threaded portion of a grout injection hole.