JP2010083558A - Water cut-off sheet for reservoir - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water cut-off sheet which allows the visual confirmation whether the joining state of a joining part is favorable or not, does not need the inspection of the joining part, and is favorable in the joining state. <P>SOLUTION: When the end of a transparent cut-off sheet 14 without added with a pigment and the end of a black cut-off sheet 12 added with a pigment are overlapped with each other with the black water cut-off sheet 12 at the lower side, and thermally fused to each other, both the water cut-off sheets are melted and integrated with each other, and a portion applied with the thermal fusion has a band and/or a strip 16 clear in the color of the black water cut-off sheet at the lower side which is thermally fused, thus allowing the confirmation of the thermally fused portion. Therefore, whether the thermal fusion is continuously applied or not can visually be checked by identifying the band or the strip 16. When it is confirmed by an experiment whether the width of the band or the strip 16, that is, the width of thermal fusion bonding, for example, 15 mm or larger, the joining state is favorable and water leakage or the like does not occur, the joining state of the joining part 16 of the water cut-off sheet by thermal fusion joining is guaranteed as favorable, and the inspection is not needed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a storage tank impermeable sheet, and particularly to a storage tank impermeable sheet for covering a tank space protection member filled and arranged in a tank space.

  For various reasons, water is stored and used underground. For example, in order to effectively use rainwater, a tank space for rainwater storage is constructed underground and rainwater is stored in this rainwater storage tank. Technology is in practical use. Here, effective use of rainwater includes, for example, spraying rainwater stored in a flower bed, discharging water for fire extinguishing when a fire occurs.

  In the rainwater storage tank, a place where the rainwater storage tank is constructed is first excavated, and crushed stone, sand, etc. are spread on the foundation, and the bottom surface is flattened. And in order to prevent the rainwater stored from the side of the rainwater storage tank from leaking, a water shielding sheet joined to a desired size by heat fusion or adhesive is laid, and the tank space of the rainwater storage tank is reduced. In order to hold the tank, a tank space protection member is installed on the water shielding sheet in the rainwater storage tank. This tank space protection member is installed by assembling a predetermined number of plastic molding units in a rainwater storage tank.

  That is, the tank space of the rainwater storage tank is filled with the tank space protection member, and its shape is maintained. And in order to cover the outer surface of the tank space protection member with a water-impervious sheet and to protect the upper surface (ceiling surface) of the tank space protection member as necessary, a protection board or the like is placed on the tank space protection member. Thereafter, the upper part of the tank space protection member is covered with water-permeable or water-permeable sheets, and earth and sand are backfilled thereon to complete the construction of the rainwater storage tank. In addition, incidental facilities necessary for inflow and outflow of rainwater will be provided as appropriate. Thus, a rainwater storage tank in which the tank space is protected by the tank space protection member assembled by a plurality of plastic molded body units is completed, and rainwater is stored therein.

  Here, the water shielding sheet for the storage tank is bonded to the required number of sheets by heat fusion or adhesive according to the size of the tank space protection member. In order to prevent water leakage and the like, the junction between the water shielding sheets is performed with great care. Inspection of the joining state of a junction part is performed as needed. In addition, it is also important to prevent damage to the water-insulating sheet due to poor adhesion between the water-impervious sheet and incidental equipment, sharp gravel in the back-filled soil due to rolling pressure at the time of back-filling after implementation, or tree roots. Attention is paid (see, for example, Patent Document 1).

  There are a negative pressure inspection method and a pressure inspection method as methods for inspecting the joint state of the joint portion of the water shielding sheet described above. FIG. 3 is an explanatory diagram of the negative pressure inspection method. Two water-impervious sheets 24, 24 having a predetermined size are joined by heat fusion or an adhesive to form a joint 20. Here, soapy water is applied on the joint 20. Then, the negative pressure capsule 50 is put on the joining portion 20 having a predetermined length, the negative pressure capsule 50 and the water shielding sheet 24 are joined by the adhesive 60, and sealed between the water shielding sheet 24 and the negative pressure capsule 50. Create a space. The negative pressure capsule 50 is provided with a see-through window 56 so that the inside can be observed. Further, the negative pressure capsule 50 is provided with a valve 52 and a vacuum gauge 58, and the sealed space is made negative pressure by the vacuum pump 54 through the valve 52. The inspection is performed by closing the valve 52 and observing the joint portion 20 from the fluoroscopic window 56 when the sealed space is in a predetermined negative pressure state while looking at the vacuum gauge 58. Here, if the pre-applied soapy water does not foam, it is determined that the joining is good, and if foamed, it is judged to be bad.

  Next, the pressure inspection method will be described. Fig.4 (a) is sectional drawing of the joined water-impervious sheet, FIG.4 (b) is explanatory drawing of a pressurization test | inspection method. As shown in FIG. 4A, the two water-impervious sheets 24, 24 having a predetermined size are joined by thermal fusion or an adhesive to form a joined portion 20. Here, the water-impervious sheets 24 and 24 are joined at two adjacent locations, and an inspection space 22 is formed between the joint 20 and the joint 20. Both ends of the joints 20 and 20 of the water-impervious sheet 24 are fastened by an end closing fastener 64, and the inspection space 22 between the two rows of joints 20 is a sealed space. At this time, an auxiliary member 64a may be used as necessary to obtain a perfect sealed space. The inspection is performed by inserting the nozzle 62 into the inspection space 22 and bringing the inspection space 22 into a pressurized state with the pump 68 or the like. The nozzle 62 is provided with a pressure gauge 62a. When the inside of the inspection space 22 reaches a predetermined pressure state, the pressure is stopped and the pressure gauge 62a is observed for a predetermined time. Here, if the pressure is maintained for a predetermined time, it is determined that the joining state of the joints 20 and 20 is good.

JP 2004-204576 A

  The conventional water shielding sheet for a reservoir layer is bonded by heat fusion or adhesive as many as the required number of water shielding sheets of a predetermined size. It is difficult to determine whether or not the joining state of the joint is good with the naked eye, and it is required to perform an inspection by a negative pressure inspection method or a pressure inspection method as necessary. However, both of these inspection methods are destructive tests and require an apparatus and jig for inspection, and the inspection time is long including the setup period.

  Therefore, it is difficult to directly visually confirm that the water-tight sheet covering the storage space protection member has a good bonding state at the bonding portion, and has only been indirectly guaranteed. For this reason, there is an increased risk that a joint having a poor joint state is overlooked and a water leakage accident occurs.

  The present invention has been made in view of the above-mentioned problems, and the purpose of the present invention is to confirm whether or not the bonding state of the bonding portion is good with the naked eye, and does not require inspection of the bonding portion. An object of the present invention is to provide a water shielding sheet for a storage tank in a good state.

In order to achieve the above object, the water shielding sheet for a storage tank according to claim 1 is:
In a water shielding sheet for a storage tank, which is a sheet for covering a tank space protection member filled in a tank space formed by excavation and having a plurality of water shielding sheets of a predetermined size joined together, the water shielding sheet is a pigment Is a transparent water-impervious sheet to which no pigment is added and a colored water-impervious sheet to which a pigment is added, which are alternately arranged, and the transparent impermeable sheet and the colored impermeable sheet are The transparent water-impervious sheet is superposed at the end of the superposed sheet, and heat fusion is performed with a predetermined width over the entire length of the superposed part.

  In the overlapping portion of the end portions of the transparent water shielding sheet and the colored water shielding sheet, there is a colored water shielding sheet on the lower side and a transparent water shielding sheet on the upper side. Before heat sealing, the lower colored water shielding sheet can be seen through because the upper water shielding sheet is transparent. When heat-sealing, both water-impervious sheets melt together and the pigment of the lower colored water-impervious sheet diffuses into the heat-sealed part, so this heat-sealed part is the lower colored impermeable sheet It will be clearly visible as a colored band or stripe. Therefore, it is possible to determine whether or not the heat fusion has been performed without interruption by visually recognizing the band or the line. In addition, with regard to the width of the band or the streak, that is, the width of heat fusion, by obtaining a predetermined width that does not cause water leakage or the like in advance in experiments, the joining state of the joint portion of the heat-sealed water shielding sheet is obtained. Guaranteed and no inspection required. Therefore, it is possible to confirm with the naked eye whether or not the joined state of the joined portion is good, and it is possible to provide a water shielding sheet for a storage tank that is well joined without requiring inspection of the joined portion.

The storage tank impermeable sheet according to claim 2 is the storage tank impermeable sheet according to claim 1,
The pigment of the colored water shielding sheet is black. When the colored water-impervious sheet is black, the color change can be easily discerned with the naked eye, and the marks, bands or streaks subjected to the heat fusion can be more clearly confirmed with the naked eye. Therefore, it is possible to provide a water-blocking sheet for a storage tank having a good joint state more reliably. Thereby, the quality of the water shielding sheet for storage tanks is guaranteed.

  According to the water shielding sheet for a storage tank of the present invention, the end of the transparent water shielding sheet to which no pigment is added and the end of the colored water shielding sheet to which the pigment is added are arranged with the colored water shielding sheet on the lower side. Since they are superposed and heat-sealed with a predetermined width, when heat-sealing, both water-impervious sheets are melted together and the heat-sealed part is the color of the lower colored water-impervious sheet that has been heat-sealed It is clearly visible as a band or streak. Therefore, it is possible to confirm with the naked eye whether or not the joined state of the joined portion is good, and it is possible to provide a water shielding sheet for a storage tank that is well joined without requiring inspection of the joined portion. Moreover, the quality of the water shielding sheet for the storage tank is also guaranteed.

  Embodiments of the present invention will be described in detail below with reference to the drawings. In addition, in this Embodiment, the water-impervious sheet for storage tanks which covers the tank space protection member with which the rainwater storage tank constructed by excavating the ground etc. is filled is assumed. This storage tank impermeable sheet is constituted by joining a plurality of impermeable sheets of a predetermined size according to the size of the tank space protection member.

  FIG. 1 relates to an embodiment of a water-proof sheet for a storage tank according to the present invention, and a portion of each end of a colored water-proof sheet 12 to which a pigment is added and a transparent water-proof sheet 14 to which no pigment is added. It is a perspective view. The colored water-impervious sheet 12 to which the pigment is added and the transparent water-impervious sheet 14 to which the pigment is not added are alternately arranged. As shown in FIG. 1, the end of the colored water-impervious sheet 12 and the end of the transparent water-impervious sheet 14 have a predetermined width so that the colored impermeable sheet 12 is on the lower side and the transparent impermeable sheet 14 is on the upper side. (Overlapping part) 18 is overlapped. In the present embodiment, the colored water shielding sheet 12 uses a black pigment.

  Here, heat fusion is not yet applied, and in the overlapped portion (overlapping portion) 18, since the transparent waterproof sheet 14 is on the upper side, the lower colored waterproof sheet 12 is transparent. It will be visible. It should be noted that the width W of the overlapping portion 18 may be any width that can at least carry out heat fusion described later.

  FIG. 2 is a plan view after heat-sealing the overlapping portion 18 shown in FIG. 1 with a predetermined width. The heat fusion was performed by a normal traveling type automatic fusion machine, and the conditions for heat fusion were the same as the conventional one except for the width of the fusion. In the present embodiment, heat fusion is performed with a width wider than usual, and specifically, the width of the heat fusion is about 15 mm. Note that the thermal fusion is performed over the entire length of the overlapping portion 18.

  When the above-described heat fusion is applied, both the water-impervious sheets are melted and united when the heat-fusing is performed, and the pigment of the lower colored water-impervious sheet 12 diffuses into the heat-sealed part. Such a portion becomes a colored band or streaks of the lower colored water-impervious sheet 12 and can be clearly seen.

  That is, before heat sealing, the upper colored water shielding sheet 14 is transparent, so that the lower colored water shielding sheet 12 was simply seen through. Thus, the heat-sealed portion can be clearly recognized with the naked eye as the color of the colored water-impervious sheet 12, that is, a black band or streak 16.

  If this band or streak 16 is formed without interruption, it is evidence that the heat fusion has been performed without interruption. Here, although the color of the colored water-impervious sheet 12 is black, when the colored impermeable sheet 12 is black, the heat-sealed portion becomes a black band or streak, so that they can be more reliably visually recognized. It becomes. However, not only black but also other colors, the heat-sealed part can be confirmed as a band or streak of the other color. There is no need to be particularly concerned.

  In the present embodiment, the width of the band or the streak 16, that is, the width of the thermal fusion is set to about 15 mm as an example in the width of the thermal fusion. For the transparent water-impervious sheet 14 and the colored water-impervious sheet 12 used in the present embodiment, if the width of heat fusion is 15 mm or more, the joining state is good and water leakage or the like does not occur in advance through experiments or the like. It has been confirmed. Therefore, by setting the width of the thermal fusion to about 15 mm, it is ensured that the coupling state of the coupling portion 16 is good and no water leakage or the like occurs. And the test | inspection of the junction part 16 of the transparent water-proof sheet | seat 14 and the colored water-proof sheet | seat 12 after heat sealing becomes unnecessary.

  In addition, since the width of the heat fusion can be clearly confirmed, the heat fusion width can be automatically read. That is, it is also possible to construct a system that performs heat fusion with an automatic fusion machine, immediately reads the width of the heat fusion with a camera or the like, and issues an alarm that the bonding is defective if it is 15 mm or less. .

  According to the present embodiment, the end of the transparent water-impervious sheet to which no pigment is added and the end of the black water-impervious sheet to which the pigment is added are overlapped with the black water-impervious sheet on the lower side, The overlapping portion is heat-sealed. Then, both water-impervious sheets are melted and integrated, and the heat-sealed part can be confirmed as clearly colored or streaked in the color of the lower black water-impermeable sheet that has been heat-sealed. Therefore, it can be visually confirmed by confirming the band or the streak whether or not the heat fusion has been performed without interruption. In addition, if the width of the band or streak, that is, the width of heat fusion is 15 mm or more, for example, it has been confirmed beforehand by experimentation that the joining state is good and water leakage does not occur. The joining state of the joint part of the water sheet is guaranteed to be good, and inspection of the joint part becomes unnecessary. Therefore, the quality of the water shielding sheet for the storage tank is guaranteed.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the present embodiment, the width of the heat fusion is set to about 15 mm as an example, but can be appropriately determined according to the water shielding sheet to be used. Moreover, although the heat fusion | bonding in a junction part is made into 1 row, you may make it ensure a more reliable coupling | bonding state as 2 rows.

It is a partial perspective view of the edge part of the colored water-impervious sheet to which the pigment is added, and the transparent water-impermeable sheet to which the pigment is not added according to the water-impervious sheet for storage tanks of the present invention. It is a top view after giving the heat-sealing to the overlapping part in connection with the water shielding sheet for storage tanks of the present invention. It is explanatory drawing of the negative pressure test method which concerns on the conventional water-impervious sheet for storage tanks, and test | inspects a junction part. It is explanatory drawing of the pressurization test method which concerns on the conventional water-impervious sheet for storage tanks, and test | inspects a junction part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reservoir sheet 12 for storage tanks Colored water-impervious sheet 14 Transparent water-impervious sheet 16 Joining part (trace of heat fusion, band or streak)
18 Superposition part

Claims (2)

In the water shielding sheet for storage tanks, which is a sheet for covering the tank space protection member filled and installed in the tank space formed by excavation and in which a plurality of water shielding sheets of a predetermined size are joined,
The water-impervious sheet is a transparent water-impervious sheet to which no pigment is added and a colored water-impervious sheet to which a pigment is added, and they are arranged alternately.
The transparent water-impervious sheet and the colored water-impervious sheet are overlapped with the transparent water-impervious sheet facing up at their ends,
A water shielding sheet for a storage tank, wherein heat sealing is performed with a predetermined width over the entire length of the overlapping portion.   The water-proof sheet for storage tanks according to claim 1, wherein the pigment of the colored water-proof sheet is black.

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