JP2003010810A - Method for repairing water-stop sheet underwater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing a damaged part of a water-stop sheet laid at the bottom or on the slope of a waste disposal site or a reservoir, especially a method for repairing the damaged part of the water-stop sheet when the sheet is laid underwater or undersea. SOLUTION: The damaged part of the water-stop sheet laid on a ground underwater or undersea, is layered with mats of a high-density bentonite. The mats are tightly pressed on the damaged part with a weight of concrete. Thus the damaged part is repaired.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a damaged portion of a water-blocking sheet laid on the bottom or slope of a waste disposal site, a reservoir, or the like. Furthermore, the present invention is a method of repairing a damaged portion of a water-permeable sheet when it is laid in water or seawater. In particular, the present invention applies revetment work for a coastal waste disposal site to a landfill zone on the coast, lays a water-blocking sheet on the bottom surface thereof to construct a waste disposal site, and discards the waste there for landfilling. When going
The present invention relates to a method for repairing a damaged portion that has occurred in a water-blocking sheet laid in seawater.

[0002]

2. Description of the Related Art Conventionally, in the construction work of a waste disposal site, a storage pond, etc., the earth is dug to form a vast depression, and a water blocking sheet is laid on the side wall and the bottom of the depression.
In such a place, when a breakage point occurs in the waterproof sheet and the breakage point is identified, the following method is performed as a repair method.

1) Method for directly repairing a damaged impermeable sheet 2) Method for waterproofing the vicinity of the damaged part of the impermeable sheet at the current position with a ground improvement agent etc. In the above 1), the impermeable sheet is exposed to the ground. If so, a method of applying a patch so as to take a lap region of 10 cm or more from the damaged portion and performing pressure bonding is performed. In this method, it is necessary to inspect the joint after repairing.

Further, in Japanese Patent Laid-Open No. 2000-160534, in a method of repairing a water blocking sheet, when there is a damaged portion at the bottom of a final waste disposal site, a reservoir or the like, or a laid water blocking sheet, it is damaged. Exposing the part and the surface around it, install a water-repellent waterproof material with a larger area than the damaged part on the damaged part through a swelling material such as swelling rubber or plastic, and then repair the surface It is disclosed that a weight is applied by mounting a backfill material or the like on the water impervious material for water.

[0005]

However, when the water-blocking sheet is underwater, it is difficult to repair the damaged portion by the conventional method. This is because the technique of joining the water-impervious sheet in water has not yet been established.In such a case, it is time-consuming but it is most certain at this stage to temporarily pull up the sheet on a ship and repair it in the atmosphere. Is done as a method.

In contrast, the present invention has been completed by developing a method capable of repairing a damaged portion of a laid water-blocking sheet in water or seawater.

[0007]

According to the present invention, a broken portion of a water-blocking sheet laid on a foundation ground in water or seawater is sandwiched from above and below by a mat made of high-density bentonite, and a heavy stone such as concrete is put on the mat. Is installed and the high-density bentonite is pressure-bonded to the damaged part of the water-blocking sheet from above and below, and the damaged part is repaired. The high-density bentonite mat laid on the lower side of the water-blocking sheet is crimped with the width slightly wider than the damaged part of the water-blocking sheet.

Specifically, in the method of the present invention, when a damaged portion is found in a water-blocking sheet laid in water or seawater, the damaged portion is repaired by the following method. 1) Use a mat made of high-density bentonite as the lower water stop layer of the damaged part, remove the protective cover adhering to the surface, insert the mat from the damaged part of the water shield sheet, and Lay so as to cover the lower part of the impermeable sheet with several times the area. By removing the protective cover and bringing the mat made of high-density bentonite into direct contact with the water-blocking sheet, the adhesion performance between the two is improved.

2) A mat made of high-density bentonite is used as the upper water stop layer at the damaged portion, the protective cover adhering to the surface is removed, and the mat is placed on the upper surface of the damaged portion of the waterproof sheet. Then, lay it so as to cover the upper part of the impermeable sheet with an area several times larger than the damaged part.

By providing the upper water stop layer and the lower water stop layer in 1) and 2) above, it is possible to surely sandwich the breakage portion of the water-blocking sheet with a mat composed of upper and lower two layers of high-density bentonite to stop water. You can

3) A foam sealing material made of polyurethane, polyethylene, or rubber sponge is laid over the upper surface of the upper water blocking layer as a cushioning material over its area. 4) Cover the entire structure of 2) and 3) above with a waterproof sheet.
As a result, the mat of the upper water blocking layer caused by the unevenness formed on the bottom surface of the protective layer / weighting layer obtained by injecting mortar into the cloth form, which is formed on the water blocking sheet later. 5) It is possible to uniformize the compression reduction to 5) Inject mortar, concrete, etc. into the cloth formwork placed over the area of the cushioning material to make weights, and then add weight to the foam seals. The weight is added to the high density bentonite mat of the upper water stop layer through the timber. As a result, the swelling action of the bentonite forming the mat and the compacting action of the cushioning material reliably prevent the bentonite from leaking from the end of the high-density bentonite mat.

Another method of the present invention is to repair a damaged portion in the following manner: 1) A sealing material or a hard board is inserted from the damaged portion of the impermeable sheet to detect the damaged portion. Place it below. As a result, a smooth surface is formed in the lower part of the water-blocking sheet, the joint surface between the upper bentonite and the lower bentonite is stabilized, and the water blocking effect can be enhanced.

2) A mat made of high-density bentonite is used as the lower water stop layer at the damaged portion, the protective cover adhering to the surface is removed, and the mat is inserted from the damaged portion of the waterproof sheet, It is installed on the upper surface of the sealing material or a hard board and laid so as to cover the lower part of the water-blocking sheet in an area several times as large as the damaged part.

3) A high-density bentonite mat is used as the upper water stop layer at the damaged portion, the protective cover adhering to the surface of the mat is removed, and the mat is placed on the upper surface of the damaged portion of the waterproof sheet. Lay so that it covers the upper part of the impermeable sheet with an area several times as large as the damaged part.

4) A foam sealing material made of polyurethane, polyethylene, or rubber sponge is laid over the upper surface of the upper water blocking layer as a cushioning material over its area. 5) Cover the entire structure of 3) and 4) with a water blocking sheet.
As a result, the mat of the upper water blocking layer caused by the unevenness formed on the bottom surface of the protective layer / weighting layer obtained by injecting mortar into the cloth form, which is formed on the water blocking sheet later. It is possible to make uniform the compression reduction.

6) A concrete layer, mortar or the like is poured into the cloth frame to cover the water-blocking sheet of 5) to form a protective layer and a weight layer. Due to the weighting, the entire water-impervious structure formed under the weighting layer can be pressure-adhered. After the repair, it can also serve as a protective layer at the repaired portion.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A mat made of high-density bentonite used in the present invention is a water-impermeable sheet in which a temporarily swollen high-density bentonite plate is surface-protected with polypropylene woven cloth or non-woven cloth, and is commercially available. . Its feature is that it does not require pre-curing at the site of use and can immediately exhibit the water-blocking effect. It can be installed on. This bentonite has a property that it is extremely difficult for water to pass through it and also has a property that it expands when it absorbs water.

The protective layer / loading layer used in the present invention is constructed by partially combining or adjoining two upper and lower layers of fiber cloth, and injecting concrete or mortar between the two layers so that both surfaces are Alternatively, it is a multi-layered mat made of concrete or mortar with unevenness formed on one surface. This protective layer and weighted layer installs the above-mentioned two-layer fiber cloth on the foundation ground of the required place in water or seawater, and injects concrete or mortar through the pipe from the injection pump on board or above the ground between the two layers. It is formed by

[0019]

Example 1 As shown in FIG. 1, when a water dam sheet 2 laid on the underwater foundation ground of a waste disposal site constructed on the coast had a damaged portion 2, The diver dives into the area, inserts the high-density bentonite mat 3 into the lower surface of the damaged area through the damaged area, and further arranges the high-density bentonite mat 3 on the upper surface of the damaged area to form two high-density damaged areas. Install by sandwiching between bentonite mats.

On the high-density bentonite mat laid on the upper surface of the damaged area, the EPD that is sufficiently larger than this mat is used.
A cushioning material 4 made of M-based rubber sponge is arranged. Furthermore,
A sufficiently large cloth formwork is installed on the upper surface of this cushioning material, and the formwork is filled with concrete to form a protective layer / weighting layer 5. The weight of the formwork forms a high-density bentonite mat through the cushioning material. Press the top and bottom of the damaged part waterproof sheet.

At this time, as the EPDM rubber sponge, SEALFLEX AGTE7010 (trade name) manufactured and sold by Inoac Corporation was used. This is because the holding water pressure for 24 hours at 100% compression is 100.
It is mmAg (measured by a U-shaped water stop test), and is a rubber sponge having a very high water stop retention property. The fabric form used was Fabry Foam sold by Asahi Kasei Geotech Co., Ltd. This is a fabric formwork that has a lightweight formwork and is capable of underwater construction, and has the characteristic that switching work and water stoppage work are unnecessary.

(Embodiment 2) As shown in FIG. 2, when a breakage point 2 occurs in a water-blocking sheet 1 laid on an underwater foundation ground, a diver dives into the water, and the breakage point is first detected. The sealing material or hard disk 6 is inserted through the through hole, and then the high-density bentonite mat 3 is placed on the upper surface of the sealing material or the hard disk through the damaged portion. Further, the high-density bentonite mat 3 is arranged also on the upper surface of the damaged part, and the damaged part is placed so as to be sandwiched between two high-density bentonite mats.

On the high-density bentonite mat laid on the upper surface of the damaged portion, the cushioning material 4 made of a rubber sponge sufficiently larger than this mat is placed, and the upper surface of this cushioning material is covered with a water-blocking sheet 1'in a wide area. Cover.

After that, a cloth mold which is sufficiently larger than this is installed on the upper surface of the water-blocking sheet 1 ', and the mold is filled with concrete to form a protective layer and a weighting layer 5. The high-density bentonite mat is pressure-bonded to the damaged water-blocking sheet from above and below through the material and the water-blocking sheet.

At this time, as the EPDM rubber sponge, SEALFLEX AGTE7010 (trade name) manufactured and sold by Inoac Corporation was used. This is because the holding water pressure for 24 hours at 100% compression is 100.
It is mmAg (measured by a U-shaped water stop test), and is a rubber sponge having a very high water stop retention property. The fabric form used was Fabry Foam sold by Asahi Kasei Geotech Co., Ltd. This is a fabric formwork that has a lightweight formwork and is capable of underwater construction, and has the characteristic that switching work and water stoppage work are unnecessary.

[0026]

INDUSTRIAL APPLICABILITY In the present invention, it is possible to construct a high-density bentonite mat by diving work, and at the time of diving work, the mat can be carried in water or seawater to search for a damaged portion of the waterproof sheet. The unique effect of the present invention is that the mat can be fixed to the damaged portion promptly after finding the damaged portion.

Further, in order to press the high-density bentonite mat to the water-blocking sheet and apply a weight to the two so as to adhere them to each other,
By placing a cloth formwork on the mat and injecting concrete or mortar into the formwork from a ship carrier, the high density bentonite water-impervious structure can be protected and weighted.

[Brief description of drawings]

FIG. 1 is a view showing a pressure-bonded repair of a damaged portion of a water-blocking sheet by a high-density bentonite mat.

FIG. 2 is a diagram showing a structure in which a damaged portion of a water-blocking sheet is covered with a high-density bentonite mat and then pressure-equalized to stop the compression of water.

[Explanation of symbols]

1, 1 ': water barrier sheet 2: Damaged part 3: High density bentonite mat 4: cushioning material 5: Protective layer and weighted layer 6: Seal material or hard board

Continued front page    (72) Inventor Yukichi Nakamura             2-12-32 Konan, Minato-ku, Tokyo SOUT             H PORT Shinagawa 4th floor Asahi Kasei Geotech             Within the corporation (72) Inventor Hiroya Nakanishi             2-13-4 Minami 2-chome, Nakamura-ku, Nagoya-shi, Aichi             No. Inoac Corporation             Within (72) Inventor Kimiaki Nagadome             Hiroshima Prefecture Fukuyama City 2-2-1 Matsuhamacho Hiroshima             Kasei Co., Ltd. F-term (reference) 2D018 DA03                 4D004 AA46 BB01 BB05 CB50 CC11                       CC17

Claims (6)

[Claims] 1. A high-density bentonite mat is used to sandwich a damaged portion of a water-impervious sheet laid on a foundation ground in water or seawater from above and below, and a heavy stone such as a concrete plate is installed from above to block the high-density bentonite. A method for repairing an impermeable sheet in water or seawater, which comprises press-bonding to a water sheet. 2. The method according to claim 1, wherein the high-density bentonite mat on the upper surface and / or the lower surface sandwiching the water-impermeable sheet is used in a state in which the high-density bentonite mat is slightly wider than the damaged portion of the water-impermeable sheet. 3. A smooth surface is formed on the lower surface of the water-blocking sheet by inserting a sealing material or a hard board from the damaged portion of the water-blocking sheet and installing it below the damaged portion. Alternatively, the method according to claim 2. 4. A foam sealing material having a polyurethane, polyethylene or rubber sponge property is laid as a cushioning material over the area of the high density bentonite mat on the upper surface of the water blocking sheet. The method according to any one of 3 above. 5. The method according to claim 1, wherein an upper surface of the cushioning material is covered with a waterproof sheet. 6. A concrete frame, a mortar or the like is injected into a cloth frame to form a weight or a protective layer and a weight layer, and the high density bentonite mat is pressure-bonded to the water-impervious sheet by the weight. 6. The method according to claim 5.