JP3702325B2 - Waterproofing of the cut surface - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waterproofing method in an open-cut method, and more particularly to a waterproofing method for a cut-off surface when an underground structure is formed when a mountain retaining wall is formed of a soil cement wall and a steel material.
[0002]
[Prior art]
Conventionally, for waterproofing underground structures, a sheet waterproofing method using a rubber asphalt sheet is generally performed.
This method, especially when waterproofing vertical wall surfaces, is heavy because the rubber asphalt itself is heavy. After making the ground surface smooth and smooth, the adhesive strength of the synthetic rubber adhesive is used to prevent the rubber asphalt from falling off. It is necessary to paste it.
When such a method is used for waterproofing an excavated mountain retaining wall, first, a wooden frame is assembled on the front surface of the mountain retaining wall, and a plywood is attached thereto to form a smooth wall surface. Next, a rubber asphalt sheet is bonded to the smooth surface with a synthetic rubber adhesive to form a waterproof surface.
[0003]
[Problems to be solved by the invention]
However, in the case of such a waterproof sheet, a joint part between the sheets is always formed. Therefore, there is a possibility that water leakage may occur if the joining is not performed reliably.
In addition, concrete is cast as a built body inside the waterproof surface. At that time, it is necessary to fill the gap between the retaining wall and the cast concrete frame with another material. When the separator for supporting the concrete panel at the time of concrete placement is attached to the H steel, there are operations such as cutting and pasting the sheet, and the work efficiency is poor, and at the same time, there is a risk of water leakage. At present, it is not fully satisfactory in terms of the reliability of waterproofing.
Furthermore, when this sheet waterproofing method is applied directly to the wall of Yamatome, the soil cement part mixed with soil and cement does not adhere to the sheet, so the adhesive strength of the H steel part alone supports the weight of the rubber asphalt sheet. The sheet may fall off.
In addition, since the above-described basic problems such as lack of workability and waterproofing are lacking, it is very difficult to apply the sheet waterproofing method directly to the mountain retaining wall.
[0004]
[Object of the present invention]
The present invention was made to remedy the above problems, and realized a seamless and highly reliable waterproof layer without joints, which has good workability, is lightweight and has sufficient adhesion to the wall of the mountain retaining wall. Therefore, it is voluntary to provide a method for waterproofing the cut surface.
[0005]
[Means for solving problems]
That is, the method for waterproofing the cut surface according to the present invention is a method for waterproofing the cut surface obtained by cutting one side of the mountain retaining wall formed by the H steel group placed in the ground and the soil cement portion disposed therebetween, This is a method of waterproofing a cut surface, in which H steel is used as an adhesive surface and the H steel is connected by a flexible film body, and then an exposed surface of the H steel and a polyurethane resin is applied to the surface of the film body. .
To that end, for example, (1) Keren process to remove H steel rust and mud,
(2) A step of applying a brimer to the H steel. (3) A flexible film body is attached to the soil cement surface between the H steel and the H steel with an adhesive using the H steel as an adhesive surface. (4) It can construct by the process of apply | coating the polyurethane resin used as a waterproof layer to a mountain wall surface using a sliding apparatus.
[0006]
[Configuration of the present invention]
The present invention is described in detail below.
[0007]
<A> Primer The primer that can be used in the present invention is not particularly limited as long as it can adhere the steel H and the polyurethane resin, but an epoxy system is preferable in consideration of the occurrence of partial rust of the H steel. Further, it is more preferable to perform a keren process for removing dirt such as rust and mud of the H steel in advance before applying the primer.
[0008]
<B> Flexible film body The flexible film body may be anything as long as it covers the soil cement part and smooths the soil cement part, but it is not limited to a synthetic resin film, a synthetic resin sheet, a nonwoven fabric or a cloth. Is preferred. As the synthetic resin film and the synthetic resin sheet, polyethylene, polypropylene, PVC, nylon and the like can be used. As the nonwoven fabric, polyethylene, polypropylene, nylon, polyester and the like can be used.
For example, considering the waterproofing of underground structures, it serves as a conduit for the generated groundwater, and also has a water shielding layer inside because of its adhesion to polyurethane resin and improved waterproof reliability (double waterproofing). A composite sheet made of a nonwoven fabric sandwiched with these films is most preferred.
[0009]
<C> Adhesive.
Adhesion of the flexible film body to the H steel can be performed using, for example, an acrylic urethane adhesive.
[0010]
<D> Waterproof coating The waterproof coating used in the present invention comprises a polyurethane resin. It is preferably an insoluble polyurethane resin, and is preferably made of an insoluble ultrafast curable two-component polyurethane resin.
Here, the non-dissolvable ultra-fast curable two-component polyurethane resin is composed of two components of a solvent-free polyisocyanate and a solvent-free polyol and / or a solvent-free polyamine, and is a two-component mixture equipped with a high-pressure spray gun. When mixed using a spray device of the type, it reacts quickly and forms a waterproof coating of polyurethane resin.
[0011]
The polyisocyanate used in these ultra-fast curable two-component polyurethane resins is not particularly limited as long as it is a general polyisocyanate used in a solvent-free type. For example, 2,4 monotolylene diisocyanate, 2,6-tolylene diisocyanate, mixtures of these tolylene diisocyanates, diphenylmethane-4,4'-diisocyanate (MDI), xylylene diisocyanate (XDI), dicyclohexylmethane-4 , 4-diisocyanate (hydrogenated MDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), hydrogenated xylylene diisocyanate (HXDI), crude tolylene diisocyanate, polymethylene polyphenyl polyisocyanate (crude MDI), etc. it can. In addition, isocyanurate-modified products, carbodiimide-modified products, burette-modified products of these polyisocyanates, and those obtained by reacting a part of isocyanate groups with polyols can be used. Among these polyisocyanates, preferred are MDI, crude MDI, and modified products thereof.
[0012]
The polyol is not particularly limited as long as it is a polyol used in a solventless type. Specific examples include liquid polyols having two or more terminal hydroxyl groups such as polyether polyols such as polyoxyalkylene polyol and polytetramethylene ether glycol, polyester polyols, polybutadiene polyols, castor oil-based polyols and polycarbonate polyols. The preferred polyol in the present invention is a polyether polyol.
[0013]
The polyamine is not particularly limited as long as it is a solvent-free polyamine. Specific examples include polyamines such as diethyltoluenediamine and 4,4′-monomethylene-bis (21-chloroaniline), and those obtained by substituting the terminal hydroxyl groups of polyols with primary and / or secondary amino groups. In particular, diethyltoluenediamine is preferable.
[0014]
The non-dissolving ultra-fast curable two-component polyurethane resin as described above may contain pigments, catalysts, water-absorbing agents, and the like. Examples of pigments include inorganic color pigments such as titanium oxide, carbon black, and bengara, organic color pigments such as phthalocyanine and azo, inorganic extender pigments such as talc, barium sulfate, mica, clay, and calcium carbonate. Examples thereof include rust preventive pigments such as zinc chromate, lead cyanamide, strontium chromate and zinc phosphate, and other pigments such as aluminum powder, glass flakes and mica powder. These pigments are preferably kneaded in advance with a polyol or polyamine. This is because when these pigments are added to the polyisocyanate component, moisture contained in the pigment may react with the isocyanate.
[0015]
As the catalyst, known organometallic catalysts and amine catalysts can be used for adjusting the curing rate. As the organometallic catalyst, fatty acid salts such as tin, lead, bismuth, and zinc can be used. Specific examples include dibutyltin dilaurate, lead octylate, and bismuth octoate. Examples of the amine catalyst include triethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, and N-ethylmorpholine. Two or more of these catalysts may be used in combination.
[0016]
If necessary, a plasticizer such as dioctyl phthalate, dibutyl phthalate, dioctyl adipate, chlorinated paraffin, and petroleum plasticizer may be used in combination with the above-described two-component urethane resin. In addition, paint additives such as stabilizers, dispersants, surface conditioners, thickeners and anti-settling agents may be added.
[0017]
<E> Application method The waterproof coating is formed by separately preparing a solvent-free polyisocyanate, a solvent-free polyol and / or a solvent-free polyamine, and a two-component mixing spray equipped with a high-pressure spray gun. Using a coating device, apply to the surface of the wall with mixing. The component that forms this waterproof coating is a solvent-free component, so there is little risk of air pollution by volatile solvents. Moreover, since the applied polyurethane resin has high component reactivity, it reacts quickly on the surface of the mountain retaining wall and cures in a few seconds to form a waterproof coating having a required thickness.
The average thickness of the waterproof coating is preferably 1 to 3 mm. If the thickness is less than 1 mm, there is a risk of water leakage due to unevenness of the partial coating film. If the thickness exceeds 3 mm, the reliability of waterproofing is improved, but the construction cost is increased.
[0018]
【Example】
Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.
[0019]
<I> Keren process.
The surface of H steel 1 that is part of the Yamato wall surface constructed by the soil cement mixing wall method is cleaned to remove floating rust and mud. A soil cement 2 is located between the H steels 1 and does not collapse even by open cutting.
[0020]
<B> Application of primer.
An epoxy primer (primer (a)) for steel plate is applied to the surface of H steel 1 by using a roller at 0.15 kg / m ² . At that time, it is also applied to the base part of the separator.
[0021]
<C> Adhesion of flexible film body.
After confirming the hardening of the primer (a), 0.2 kg / m ² of acrylic urethane adhesive 3 is applied to the affixed portion of H steel 1 (about 50 mm at both ends of H steel 1) using a roller.
After the adhesive 3 is applied, a flexible film body, for example, a nonwoven fabric 4 is attached so that the overlap width with the H steel 1 is about 50 mm on each of the left and right sides with an open time of 15 to 30 minutes (20 ° C.). The upper part (soil cement part) of the nonwoven fabric 4 is nailed in order to prevent turning.
[0022]
<D> Formation of coating film.
Next, a waterproof coating film is formed. For this purpose, a solventless ultra-fast curable two-component polyurethane resin (waterproofing material b) is spray-applied sequentially from the upper part to the lower part so that the thickness of the waterproof coating 5 is 2 mm on average.
[0023]
[Evaluation]
<I> Adhesiveness between H steel and waterproof coating Apply 0.15 kg / m ² of the brimer (a) to the H steel, and after applying the primer (a), apply the waterproof material (b) to an average thickness of 2 mm. After curing, the adhesive strength was measured by a peeling method using a push full gauge. In Examples, the adhesive strength was 10 kg / 25 mm width or more, and it was confirmed that the adhesive strength was sufficient.
[0024]
<B> Penetration test The waterproof material (b) was applied to the nonwoven fabric so as to have an average thickness of 2 mm, and after curing, a penetration test was conducted in accordance with JlSL1018. In the examples, the maximum burst strength was 100 kg or more, and it was confirmed that the film had sufficient penetration resistance.
[0025]
<C> Watertightness A nonwoven fabric as an example of a flexible membrane was sandwiched between a tester (pressure filter) as shown in FIG. 3, water was added into the cylindrical container, and pressure was immediately applied. After the test was performed until the amount of flowing water became constant at 2 kg / cm ² , the pressure was increased to 3.5 kg / cm ² and measurement was performed until the amount of flowing water became constant again. From the flow rate, the hydraulic conductivity was calculated according to Darcy's law. In the examples, the water permeability was 0, and it was confirmed that sufficient water tightness could be secured.
The hydraulic conductivity was determined by the following formula.
K = p × h / P × Q / A
K: hydraulic conductivity (cm / s)
p: Water density (kg / cm ³ )
h: sample thickness (cm)
P: Water pressure (kg / cm ² )
Q: Flowing water volume per sample area (cm ³ / s)
A: Sample area (cm ² )
[0026]
【The invention's effect】
Since the method for waterproofing the cut surface according to the present invention is as described above, the following effects can be achieved.
<I> The unevenness of the soil cement part can be smoothed with a nonwoven fabric that is lightweight and has good workability. As a result, the entire wall surface can be smoothed.
<B> Since a solvent-free polyurethane resin is uniformly applied to the wall surface of a mountain using a two-component type spray coating device equipped with a high-pressure spray gun, a joint part like a waterproof sheet is formed. Therefore, reliable waterproofness can be ensured.
<C> The treatment of the separator portion attached to the H steel is completed by simply applying a polyurethane resin.
Therefore, work efficiency, waterproof reliability, and the like are improved.
<D> Since no volatile solvent is used, the environment is not polluted and the working environment of workers is good.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a construction state of a waterproofing method of the present invention.
FIG. 2 is an enlarged explanatory view of a waterproof part.
FIG. 3 is an explanatory diagram of a water resistance test.

Claims (3)

A method of waterproofing a cut surface obtained by excavating one side of a mountain retaining wall formed by a group of H steel cast in the ground and a soil cement portion disposed therebetween,
H steel is used as an adhesive surface, and the H steel is connected by a flexible film body.
Thereafter, a polyurethane resin is applied to the exposed surface of the H steel and the surface of the film body,
Waterproofing method for the cut surface. As a flexible film body,
Use synthetic resin film, synthetic resin sheet, non-woven fabric, or cloth,
The method for waterproofing the cut surface according to Item 1. As a flexible film body,
The method for waterproofing a cut surface according to claim 1, wherein a nonwoven fabric sandwiched with a film of a water shielding layer is used.

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