JPH0118719Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention partially closes the gap between the wall surface of a borehole or casing pipe, etc. and the outer circumferential surface of a cylindrical body inserted into the inside. Regarding the packing material used to block (packing) the flow of water in the longitudinal direction, more specifically, it is made of a band-shaped water-absorbing and swelling polymer material, and has a plurality of protrusions extending in the longitudinal direction on one or both sides thereof. The present invention relates to a water-blocking packer material which has a structure and is used by being wrapped around the outer periphery of the cylindrical body.

[Prior Art] Accurately understanding the properties of groundwater is one of the essential items in order to manage the amount and quality of groundwater and to know the properties of the ground for civil engineering purposes. Groundwater usually exists in aquifers divided into several to tens of layers in the ground, and various properties such as pressure, water quality, water volume, flow velocity, flow direction, etc. differ for each aquifer. Therefore, when drilling a borehole underground to investigate the properties of groundwater, the aquifer to be investigated must be separated from other aquifers and kept separate. It won't happen. Therefore, the gap between the borehole wall and the cylindrical body such as the casing or measuring instrument inserted into the borehole is partially closed at an appropriate position by some kind of water-blocking means, and the casing or measuring instrument is the object of investigation. It is necessary to make it possible to contact only the groundwater of the aquifer.

Conventional water-shielding technology involves placing a rubber tube over a cylindrical body at a predetermined position on the outer circumference, tightening both ends, and sending high-pressure fluid (air or water, etc.) from the ground between the outside of the cylindrical body and the inside of the rubber tube. There is a device that expands and packs the material until it contacts the hole wall. In addition, there are other techniques such as injecting cement or bentonite into the depth of the hole where water is to be blocked and solidifying it for packing.

[Problems that the invention aims to solve] However, in conventional drills using rubber tubes, equipment such as air compressors and high-pressure water pumps is required on the ground, and air and water are not pumped from the ground surface to a specified depth inside the hole. You will also need a hose to guide it. These hoses inevitably pass through the inside of the cylindrical body, which becomes an obstacle when various measuring instruments are inserted into the cylindrical body. Therefore, the diameter of the cylindrical body must be increased, and the diameter of the borehole or casing pipe into which the cylindrical body is inserted must also be increased, resulting in a large economic loss.

Furthermore, the method of injecting cement or bentonite has problems in terms of workability and reliability. It is common for boreholes to bend somewhat during drilling;
The degree of bending increases as the boring depth increases. The success of packing by injecting cement or bentonite depends on the degree of curvature of the borehole, and is not always successful. In order to increase the reliability, the boring diameter has to be increased, which leads to large economic losses.

The purpose of this invention is to eliminate the above-mentioned drawbacks of the conventional technology, eliminate the need for installing high-pressure pump equipment on the ground surface, or inserting hoses etc. into the inside of a cylindrical body. It is extremely economical as it can be kept to the minimum required level, and a sufficient water shielding effect can be obtained after a certain period of time by simply inserting it at a predetermined depth where groundwater exists and where it should be shielded. Therefore, it is easy to work, works reliably, has no risk of failure, has an extremely simple structure, can be applied regardless of the diameter of the cylindrical body to which it is attached, and can be manufactured at low cost. Our purpose is to provide water-use patch car material.

[Means for Solving the Problems] The present invention, which can achieve the above objects, is made entirely of a strip-shaped water-absorbing and swelling polymeric material, and on both or one side of the material, a strip of water-absorbing and swelling polymer material is provided that is continuous in the longitudinal direction. This waterproof packer material has a structure in which a plurality of extending protrusions are formed in the width direction, and is used so as to be wound around the outer periphery of a cylindrical body.

Here, the term "water-absorbing and swelling polymeric material" refers to a polymeric material that has the property of absorbing water and expanding when it comes into contact with water. The material is selected so that the rate of expansion can be appropriately controlled so that the material does not fully expand within the time required for the material to be inserted into the hole to a predetermined depth.

It is preferable that the plurality of protrusions be formed on both the front and back sides of the water-absorbing and swelling polymer material in the form of a band. It is most preferable to have a structure in which the protrusions fit into the concave grooves exactly when the protrusions are rolled up.

Furthermore, since this water-shielding packer material is wound around the outer circumferential surface of the cylindrical body once or multiple times, it is desirable that it has a thin structure with enough flexibility to cope with the wrapping.

[Function] The water-blocking packer material according to the present invention is wound around the outer peripheral surface of a cylindrical body such as a casing or a measuring instrument, and is inserted into a borehole or the like. If groundwater exists and reaches a predetermined depth to be blocked, it is left as is. The water-blocking packing material then absorbs the surrounding groundwater and continues to expand, tightly sealing the spaces between the cylindrical body and the borehole wall, as well as between the rolled-up expandable polymer materials. do.

In particular, in the case where protrusions are arranged in parallel on both the front and back sides, the protrusions fit into the grooves, creating a large resistance to slipping at the interface due to force in the axial direction of the cylindrical body.
They will not fall off from the cylindrical body and will be tightly coupled to each other. As a result, when conducting a groundwater investigation, for example, the aquifer to be investigated can be separated from other aquifers and maintained in an independent state, and various measurements can be performed.

[Example] Hereinafter, the present invention will be explained in more detail based on the drawings. FIG. 1 is a perspective view showing an embodiment of the waterproof packer material according to the present invention. As is clear from the figure, water-blocking patcher material 1 according to the present invention
0 is composed of a flexible water-absorbing and swelling polymeric material 12 having a band-like shape as a whole, and has a structure in which a plurality of protrusions 14 continuously extending in the longitudinal direction are formed in the width direction on both the front and back sides. Therefore, as a matter of course, a groove 16 is formed between adjacent protrusions 14.

The water-swelling polymer material may be any conventionally known starch-based, cellulose-based, polyvinyl alcohol-based, acrylic-based, etc., such as acrylic acid/vinyl alcohol copolymer, sodium acrylate polymer, acrylic, etc. The main raw materials are acid soda/acrylamide copolymer, starch/polyacrylic acid copolymer, etc., and other materials are blended and molded into a predetermined shape. Among these, for example, those containing an acrylic acid/vinyl alcohol copolymer as the main component and blending and kneading ethylene/vinyl acetate alcohol, rubber, etc. are particularly effective. When this kind of material comes into contact with liquid water, it incorporates water molecules into its molecular structure, and at the same time it absorbs water, it has the effect of expanding its volume, and by changing the type and amount of compounding agents, the amount of expansion and the rate of expansion can be changed. can be changed.

Such water-absorbing and expanding polymeric materials are made of materials that do not fully expand within that time, taking into consideration the time required to install the cylindrical body part to be water-blocking at a predetermined depth in the borehole. The combination ratio is selected. In addition, the width and thickness of the packer material, the height and width of the convex stripes, the forming pitch, etc., and the number of times it is wrapped around the outer circumference of the cylindrical body are determined by the expansion performance of the material used, the groundwater pressure between the hole wall, etc. It will be determined by the frictional resistance that can be resisted, the length that should be water-shielded, etc.

Next, a method of using the water-blocking packer material according to the present invention will be explained. First, as shown in FIG. 2, the water-shielding packer material 10 is wound around a predetermined position of the cylindrical body 18 to be water-shielded a predetermined number of times. As clearly shown in FIG. 3, this winding is done so that the protrusions 14 on one side fit into the grooves 16 on the other side, and the outermost periphery is wrapped with a string, wire, or rubber band. Tie it up to keep it in shape. Then insert it into the borehole. At this point, the water-swelling polymeric material will begin to expand when it comes into contact with groundwater, but the rate of expansion is controlled so that it does not fully expand within the time required for insertion and remains small in diameter. It can be lowered smoothly with almost no contact with the wall.

Once it has been lowered to the specified depth where groundwater exists and should be blocked, leave it as is. Then the fourth
As shown in the figure, the water-blocking packer material 10 continues to absorb surrounding groundwater and expands completely, and the rolled-up water-absorbing and swelling polymer materials come into pressure contact with each other, and the surrounding hole walls 20 and cylinder It also comes into close contact with the outer peripheral surface of the shaped body 18 and exerts pressure on them. In this way, the expanded substance becomes an elastic body with a large amount of strain, and the water-absorbing and swelling polymeric materials adhere to each other and become water-impermeable. This makes it possible to completely block out the groundwater above and below that exists in the gap between the cylindrical body 18 and the borehole wall 20.

The present packer material 10 is extremely easy to work with because it is only necessary to wrap it around a predetermined position on a cylindrical body, lower it to a predetermined position in a borehole or casing pipe where ground water is present, and continue to hold it as it is. In addition, since it is only necessary to cut and wrap the appropriate length according to the diameter of the cylindrical body to be attached and the diameter of the boring hole, etc. to be closed, one type of packer material can be used for cylindrical bodies of various diameters. It is highly flexible and extremely easy to use.

In particular, as in the above embodiment, if a plurality of protrusions 14 are provided on both the front and back surfaces of the band-shaped water-swelling polymeric material 12, and the protrusions 14 are fitted into the grooves 16, the cylinder The large clearance between the cylindrical body and the pore wall prevents slippage between the multilayered water-absorbing and swelling polymer material when the cylindrical body is rolled up several times. Because it is arranged in the circumferential direction rather than in the axial direction, it has a large blocking ability against the flow in the axial direction and is difficult to seep out.Furthermore, when it expands, the convex portion preferentially blocks the borehole wall and the cylindrical body. Since it is in close contact with the outer periphery, it is extremely advantageous in that it can provide more complete water shielding.

Next, Fig. 5 shows the water-blocking packer material 3 according to the present invention.
0 is shown. In this embodiment, protrusions 34 are formed at mutually corresponding positions on both the front and back surfaces of the strip-shaped water absorbing and swelling polymeric material.
When it absorbs water and expands, the protruding stripes 34 especially swell, so if a packer material 30 with such a structure is used, the protruding strips 34 will bulge outward on both sides, causing a gap between it and other members that come into contact with it. This improves the adhesion between the materials and the waterproof materials, further improving water-blocking performance.

FIG. 6 shows yet another embodiment of the present invention. Here, the packer material 40 has a convex strip 44 formed only on one side of a band-shaped water-absorbing and swelling polymer material.
The other surface 46 has a flat structure. Such a packer material 40 is preferable when used by wrapping it around a cylindrical body only once. In that case, the flat surface 46 is on the inside, and it is preferable to wrap it tightly around the cylindrical body and fix it. In addition, when the packer material 40 having the structure shown in this embodiment is wound in multiple layers, it is wound once on the innermost layer in contact with the cylindrical body, and then a water-blocking material 40 having the structure shown in FIG. 1 or FIG. It can also be used when wrapping Patsuka material in layers.

[Effects of the invention] Since the present invention is a water-shielding material constructed as described above, the structure is extremely simple and can be produced at low cost, and it can be simply inserted at a predetermined depth where groundwater exists and left as is. After a certain period of time, the expansion is automatically completed and a good water-shielding effect is obtained, making the water-shielding work extremely easy and has many excellent effects such as being reliable and reliable. be.

Furthermore, according to the present invention, it is not necessary to install equipment such as a high-pressure pump on the ground surface, and since a hose etc. does not pass inside the cylindrical body to be inserted, the diameter of the cylindrical body can be reduced, and accordingly, excavation can be carried out. It is extremely economical because the diameter of the boring hole can be kept to the minimum necessary.

Furthermore, it is not affected by the size of the diameter of the cylindrical body to be attached because it can be cut to an appropriate length before use, and even if the diameter of the borehole to be water-shielded is large, the number of times it is rolled up can be adjusted. Another advantage is that one type of patch car material can be used in a variety of cases.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the waterproof packer material according to the present invention, Fig. 2 is an explanatory view showing the state in which it is attached to a cylindrical body, and Fig. 3 is a longitudinal sectional view thereof.
FIG. 4 is a conceptual diagram showing a state in which it expands in a borehole and blocks water, and FIGS. 5 and 6 are cross-sectional views showing other embodiments of the water-blocking packer material according to the present invention, respectively. . 10, 30, 40...Waterproof patcher material, 12
...Water-absorbing and swelling polymer material, 14, 34, 44...
...Convex strip, 16... Concave groove, 18... Cylindrical body, 20...
...borehole wall.

Claims (1)

[Claims for Utility Model Registration] 1. The whole is made of a water-absorbing and swelling polymer material in the form of a band, and on at least one surface thereof, a plurality of convex stripes extending continuously in the longitudinal direction are formed in the width direction. A water-blocking material featuring: 2. The water-blocking packer material according to claim 1, wherein a plurality of convex stripes are formed on both the front and back sides of the strip. 3. The width of the protruding stripes and the width of the groove formed by the adjacent protruding stripes are approximately equal, and when the protruding stripes are overlapped, the protruding stripes fit into the grooves. Water-shielding packer material as described in item 2.