JPH0799076B2 - Water absorbing expansive water blocking material and water blocking method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-absorptive stopper which is a composite of molded articles made of a water-absorptive material which is soft and has a high expansion rate and a hard water-expansion material which has a low expansion rate in a predetermined arrangement. The present invention relates to a water material and a method of stopping water in a hole using the water material. This water-stopping material and water-stopping method using it include water-stopping for anchor lock bolts and earth anchors, water-stopping for grout inlets, packers for boring holes, and water-stopping for mouth treatment at drainage holes. This technique is suitable for stopping water in the borehole and various pipes.

[0002]

2. Description of the Related Art Recently, a water-absorptive material has been used as a water blocking material for anchor lock bolts and earth anchors, a water blocking material for grout injection ports, and the like. All of them are molded bodies made of a single material, and, for example, when rapid expansion is required, a sponge-like urethane resin imparted with water-absorptive property is often used. When a large expansion pressure and a high strength at expansion are required, such as a packer in a boring hole, a synthetic rubber or natural rubber-based material having water-absorptive properties is used.

The work is performed in the following procedure, for example. First, an anchor lock bolt, an earth anchor, and a grout injection pipe are inserted into the underground hole, and the water blocking material is arranged between them and the hole wall. Then, cement milk or grout material is injected until the excess injection material overflows from the hole mouth. As a result, it can be seen that the injection material has been sufficiently injected, and the water of the excess material is absorbed, and the water blocking material expands to stop the water. Also, in the case of a packer such as a boring hole, it absorbs the surrounding groundwater and expands to stop the water.

[0004]

In stopping water such as anchor lock bolts, it is necessary for the water stopping material to quickly absorb water and expand when the injected material overflows from the hole mouth to exhibit a sufficient water stopping effect. . In this respect, a material which is made of a sponge-like urethane resin and has water-absorptive expansivity is preferable because it has an extremely high expansion rate (usually expands in a few minutes). However, this kind of material is very soft and has low strength,
As it expands, it tends to deform unevenly in the length direction (pipe axis direction) and lose its packing function. Further, when the injection direction of cement milk or grout material is upward, the weight of the injection material cannot be supported. Furthermore, if water is present in the surroundings and you try to insert it at a position away from the hole opening, the water blocking material will expand near the hole opening before it is completely pushed in, and it will not be possible to insert it up to the specified position. It also happens that the water stop function cannot be achieved at the position.

On the other hand, a material which is made of synthetic rubber, natural rubber or the like and has water-swelling expansibility exhibits sufficiently large strength and expansive pressure upon expansion, and therefore can support the weight of the injected material. However, this type of material has a slow expansion rate (usually, it takes several hours to several tens of hours for expansion), and it is impossible to immediately exert a sufficient water blocking effect when the injected material overflows from the hole mouth. In addition, since it takes a long time even if water is absorbed and expanded by separately pouring water separately, it takes a long time to start the injection work, and there is a drawback that the work efficiency becomes low.

The object of the present invention is to solve the above-mentioned drawbacks of the prior art, to rapidly expand and stop water when necessary, and to exert a sufficiently large strength and expansion pressure to inject material, gap filling material, etc. (EN) Provided are a water-absorptive and water-stopping material that can support the weight of the above and has good workability, and a water-stopping method using the same.

[0007]

The present invention, as shown in FIG. 1, is such that a molded body 10 made of a water-absorbent expansive material that is soft and has a high expansion rate is sandwiched between both sides so that it is hard and has a low expansion rate. It is a water-absorptive and water-stopping material in which a molded body 12 made of a flexible material is arranged. As the water-swellable and expansive material which is soft and has a high expansion rate, a sponge-like polyurethane resin imparted with water absorbency that expands in a few minutes is preferable. Also, as a water-absorbent expansive material that is hard and has a slow expansion rate,
A synthetic rubber that imparts water absorbency that swells in several tens of hours is suitable.

Further, according to the present invention, as shown in FIG. 2, the gap between the pipe 16 inserted into the hole 14 and the wall surface 18 of the pipe is formed in a shape corresponding to the cross-sectional shape of the hole 14 and the pipe 16. The above-mentioned water-absorption-expandable water-stopping material is
12 are inserted so that they are closely aligned in the longitudinal direction of the pipe,
It is a construction method that absorbs the water existing in the surroundings and expands it to stop the water. Here, each molded body may be integrated with an adhesive or the like, or another molded body may be arranged and inserted so as to simply adhere to each other.

[0009]

When the hard molded bodies 12 are arranged on both sides of the soft molded body 10, as shown in FIG. 2A, when the hard molded bodies 12 are inserted into a hole or the like, the soft molded bodies 10 on both sides are softened by the hard molded bodies 12 on both sides.
Even if the insertion depth becomes long, or even if some water is absorbed and expanded, it can be easily inserted to a predetermined position. Then, as shown in FIG. 2B, first, at a predetermined position, the soft molded body 10 absorbs surrounding moisture and quickly expands. Since both sides are protected by the hard molded body 12 to absorb water and expand, uneven expansion in the axial direction does not occur. As a result, an initial water blocking effect between the pipe 16 and the hole wall surface 18 is obtained. After a lapse of several hours thereafter, the hard molded body 12 gradually expands due to water absorption, and as shown in FIG. 2C, the whole thereof absorbs water and expands to close the gap.

Here, since the molded body 10 is soft, even the wall surface 18 of the hole having a rough surface conforms to the irregularities and closely adheres to enhance the water blocking effect. The hard molded body 12 exerts sufficient strength and expansion pressure, guards the soft molded body 10 and also has a function of supporting a load such as an injection material.

[0011]

EXAMPLE FIG. 3 is a perspective view showing an example of a water-absorptive and water-stopping material according to the present invention. This water-swellable water-stop material 20
Is useful when the grout pipe injection 32 is installed in the underground hole 30 and the cement 34 is injected and fixed in the upper clearance, as shown in FIG.

This water-swellable water-stop material 20 comprises a molded body 22 made of a soft, fast-swelling water-swelling material, and hard, slow-swelling water-swelling material positioned on both sides of the molded body 22 so as to sandwich it. And a molded body 24. The molded bodies 22 and 24 are in the shape of a disk or a cylinder and have a structure in which two large and small circular through holes 26 and 28 are provided at the same location. Here, the soft water-swellable material is a sponge-like urethane resin containing a water-swellable polymer compound (for example, vinyl alcohol-acrylate copolymer or polyacrylate), and has a thickness of 15 mm. In this case, the volume expands about 8 times in about 5 minutes. Hard water-swellable material,
The same water-swellable polymer compound is blended with synthetic rubber. When the thickness is 3 mm, the volume is about 2 hours in about 24 hours.
It will be 5 times. The expansion time of each molded product changes depending on the composition of the material, the thickness and shape of the molded product. The thickness of the molded body 22 used in this example is 15 mm, and the molded body 2 is
Both 4 have a thickness of 6 mm, their diameter is 84 mm, the diameter of the circular through hole 26 is 48 mm and the diameter of the circular through hole 28 is 18 mm. The three molded bodies 24, 22, 24 may be in a state of being in close contact with each other at the time of use, and may be previously integrated with an adhesive or the like.

In the example shown in FIG. 4, the tip side has a small diameter (76 mm
φ), the hole side has a large diameter (86 mmφ) and a two-step underground hole 30 is formed by boring. The hard molded body 24, the soft molded body 22 and the hard molded body 24 are inserted in a state in which they are closely arranged in that order in the longitudinal direction of the pipe. In practice, the large-diameter grout injection pipe 32 is inserted into the large-diameter circular through hole 26, and the small-diameter discharge pipe 36 is inserted into the small-diameter circular through hole 28, and is lowered into the underground hole 30 in that state. Here, since the groundwater level surface was present above the depth at which the water-absorptive water-stopping material 20 was installed, expansion started immediately after the water-swellable water-stopping material 20 was inserted, and after 3 to 5 minutes had elapsed. The soft, water-swellable material completely expanded and adhered to the hole wall.
Then, 10 minutes after the insertion, when cement 34 was injected into the gap between the grout injection pipe 32 and the discharge pipe 36 and the wall surface of the hole from the upper part, the hole was filled with the cement at a substantially prescribed injection amount. Even after a while, the injected cement did not come off, and it was possible to confirm the water-stopping property and the cement-retaining property of the water-absorptive water-stopping material 20.

In this example, after the water stop is completed, the grout is injected from the grout injection pipe 32 to the inner bottom portion of the underground hole 30, and it is confirmed that excess grout overflows from the discharge pipe 36, and the injection work is completed. It is a thing.

The present invention is also useful for stopping water in underground holes and various pipes, such as water stopping of anchor lock bolts and earth anchors, packing of boring holes, and water stopping of mouth treatment at drainage holes. Is. Particularly, it is effective when a load is applied to the water blocking material, for example, when filling the upper part of the water blocking material with a gap filling material such as cement in the downward hole as described above, or when injecting the injection material upward. .

The above embodiment has a three-layer structure in which a molded body of a water absorbent expansive material which is soft and has a high expansion rate is arranged on both sides of a molded body of a water absorbent expansive material which is hard and has a slow expansion rate.
When higher water-stopping performance is required, a multilayer structure may be used in which a plurality of soft molded bodies are arranged and a hard molded body is inserted in the middle. The shape (thickness and outer surface shape) of each formed body, the presence or absence of holes, and the number and shape of holes can also be appropriately changed according to the usage state.

[0017]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a molded body made of a water-absorbent expansive material that is hard and has a low expansion rate is disposed on both sides of the molded body made of a soft water-expandable material that has a fast expansion rate. By doing so, it is possible to obtain an ideal water-absorption-expandable water-stopping material that has a strength and an expansion pressure that can stop water quickly and withstand a load such as an injection material. The waterproof material of the present invention is
Since the standby time until water absorption and expansion is short and the water stopping performance is high, according to the method of the present invention, the working efficiency can be improved, and various injection materials can be held reliably.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a water-absorptive and water-stopping material according to the present invention.

FIG. 2 is an explanatory view of the principle of the method of the present invention.

FIG. 3 is an exploded perspective view showing an embodiment of a water-absorbing expansive material according to the present invention.

FIG. 4 is an explanatory view showing an example of the method of the present invention.

[Explanation of symbols]

10,22 Molded body made of water-absorbent expansive material having soft and fast tonicity rate 12,24 Molded body made of water-absorbent expansive material having hard and slow expansion rate 14 Hole 16 Tube 18 Hole wall surface 20 Water-absorbent expansive water-stop material 30 Underground hole

Claims (3)

[Claims] 1. A water-absorbing material characterized in that a molded body made of a water-absorbent expansive material having a low expansion rate is arranged on both sides of the molded article made of a soft, water-expandable expansive material having a high expansion rate. Expansive waterproof material. 2. A water-swellable material that is soft and has a high expansion rate, and is made of a sponge-like polyurethane resin that is water-swellable and expands in a few minutes. The water-absorptive and water-stopping material according to claim 1, wherein a synthetic rubber imparting water absorbability that expands in several tens of hours is used. 3. A method of stopping water by disposing a water-stopping material in a gap between a pipe inserted into the hole and a wall surface of the hole, wherein a shape corresponding to a cross-sectional shape of the hole and the pipe is formed. Two
The water-absorbing expansive water-stopping material described above is inserted so that the respective molded bodies thereof are sequentially arranged in close contact with each other in the longitudinal direction of the pipe, and absorbs water existing in the surroundings to expand and stop the gap. A water stop method.