JP2002316118A - End treatment structure of impervious sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a water leak from an end surface of an impervious sheet by a method wherein an auxiliary sheet is placed on an end of the impervious sheet to cover an end surface of the impervious sheet with a fusing material, thereby completely sealing the end of the impervious sheet. SOLUTION: In the end treatment structure of an impervious sheet to detect a water leak thereof by means of an electroconductive member, the auxiliary sheet 7 is placed on an end 6 of an impervious sheet 1 in such a manner that a fusing material 9 is disposed so as to bridge the sheet 1 and the sheet 7, whereby the end 6 of the sheet 1 is covered and sealed with the material 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end treatment structure for a water-impervious sheet laid on a base such as a waste disposal site or a reservoir, and more particularly, to a water-impervious sheet having a conductive property for detecting water leakage. The present invention relates to a treatment at an end portion of an embedded member in order to prevent water from entering from the end portion.

[0002]

2. Description of the Related Art In a landfill type waste disposal site for dumping industrial waste and general waste, in order to prevent sewage leaking from the disposal site from penetrating into the underground and causing environmental pollution, the waste disposal site must be disposed of. It is compulsory to apply a seepage control to the bottom. There are various types of water-blocking works, but a method of laying a resin-made sheet or a rubber-made water-blocking sheet is often adopted in terms of reliability, safety, workability, and economy.

[0003] In order to prevent water leakage, a water-blocking sheet is laid on the bottom of a facility for storing water in a recess such as a reservoir, a reservoir, or a pool, in order to prevent water leakage. Further, in an underground structure or the like, a waterproof sheet may be laid to cover the structure in order to prevent groundwater from leaking into the structure.

[0004] It is difficult to cover these water-impervious sheets at once with a single sheet of water-impervious sheet covering the bottom of a water storage facility such as a waste disposal site or a reservoir with a large area, or the periphery of a structure. For this reason, construction is being performed to cover the entire area around waste disposal sites, water storage facilities, and underground structures by joining and integrating multiple water-impervious sheets on site.

However, in such a waterproof sheet,
It is necessary to prevent the water-impervious sheet from being damaged or the joint failure at the joint, and prevent the water contaminated by waste from leaking to the groundwork.If water leakage occurs, immediately detect the occurrence of water leakage, The damage must be repaired.

There are various methods for detecting breakage of the water-impervious sheet. Among them, a mesh material made of conductive fibers such as metal fibers or metal-coated synthetic fibers in a water-impervious sheet made of an elastomer. There is a method in which the occurrence of water leakage is electrically detected by burying the above.

[0007] A double water-impervious sheet is laid on the base, and a space is provided between the double water-impervious sheets. When water leakage occurs, drainage from the space between the water-impervious sheets is generated. There is also a method of knowing the breakage of the impermeable sheet,
In terms of facilities, such as the need to arrange a large number of drain pipes under the impermeable sheet, there is an advantage that the company-wide method of electrically detecting can be provided more easily.

In this electrical detection system, a base cloth is usually buried in an elastomer such as rubber or resin, and a conductive member is disposed in a part of the base cloth. Water is transmitted to reach the conductive member, and a change in voltage, current, resistance value, and the like can be detected.

If the base cloth or the conductive member is exposed at the end of the water-impervious sheet and is in a state of being submerged therefrom, detection cannot be performed. Therefore, it is necessary to keep the end of the impermeable sheet in a sealed state.

On the other hand, the waste disposal site has a large area, and the impermeable sheet is a wide sheet obtained by joining a plurality of sheets in a width of 1 to 2 m or in the width direction. The sheet is brought to the site to be laid and constructed, but the end in the width direction of the sheet can be sealed in advance in the factory by a method such as fusion. However, since the longitudinal ends are cut and used on site, the sealing of the longitudinal ends must be performed on site.

Conventionally, there has been adopted a method in which a sealing material made of epoxy, urethane, butyl rubber, or the like is applied to the end of the water-impervious sheet to cover and seal the end, or a sheet made of a thermoplastic resin tape is used. A method such as heat-sealing the end portion has been adopted.

[0012]

However, such a sealing material as described above has a poor pressure resistance before being cured, and even if sealing is performed, the sealing material is peeled off by an external force applied later, resulting in poor sealing. Often. Also, in the method of fusing in a state where the end is sandwiched by using a tape made of a thermoplastic resin, the fusion of the tape has to be a hand-type hot air or a method using a heating iron. In addition, uneven adhesion is likely to occur, and high fusion strength cannot be obtained.

Accordingly, the present invention solves the above-mentioned problems and proposes a method for treating an end portion of a waterproof sheet used in an electric leak detection system, and ensures that water is leaked from the edge of the waterproof sheet. An object of the present invention is to provide a highly reliable water leakage detection system by preventing the leakage.

[0014]

According to a first aspect of the present invention, there is provided a water impermeable sheet having a conductive material embedded in a thermoplastic material, wherein the water impermeable sheet is damaged. In the end treatment structure of the impermeable sheet such that the infiltration of water can be electrically detected using the conductive member,
A thermoplastic auxiliary sheet is superimposed on the end of the water-impervious sheet, and a fusible material is arranged so as to cover the end face of the water-impervious sheet so as to straddle the water-impervious sheet and the auxiliary sheet. The part is sealed.

[0015] The auxiliary sheet is superimposed on the end of the water-impervious sheet, and the fusing material is arranged so as to straddle both sheets so as to cover the end surface of the water-impervious sheet. It is completely sealed and can prevent infiltration from the end face of the impermeable sheet.

According to a second aspect of the present invention, there is provided a water-impervious sheet end processing structure in which a taper is formed at an end of the water-impervious sheet to eliminate a step with the auxiliary sheet.

By smoothly connecting the end of the water-impermeable sheet and the auxiliary sheet, the fusing material easily covers the front surface of the end surface of the water-impermeable sheet, and a gap is generated between the fusion material and the water-impermeable sheet. Can be prevented, and peeling of the fusion bonding material from the impermeable sheet can be prevented.

According to a third aspect of the present invention, the water-impervious sheet and the auxiliary sheet have an end treatment structure for the water-impervious sheet having a width of 10 to 50 mm, and the fusion material has sufficient strength for the water-impervious sheet and the auxiliary sheet. Therefore, there is no need to worry about peeling of the fusion material, and it is possible to prevent the problem of water seepage into the water-impermeable sheet.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a main part showing an end treatment structure of a water-impervious sheet according to the present invention, FIG. 2 is a cross-sectional view of a case where a water-impervious sheet is laid at a waste disposal site, and FIG. FIG.

In FIG. 1, a water-blocking sheet 1 is obtained by embedding a conductive member 3 in an elastomer 2, and the conductive member 3 is, as shown in FIG. And a conductive wire 5, a conductive yarn, and the like. In such a water-impervious sheet 1, the end of the conductive wire 5 is connected to an electrode while being laid on the ground, and the voltage, current, resistance value, and the like are observed, and a change in the numerical value is detected to detect breakage of the water-impervious sheet. Is what you do.

For example, when the elastomer 2 of the water-blocking sheet 1 is damaged and water enters through the holes, the water flows through the base cloth, flows into the water-blocking sheet, and reaches the conductive wire. The value of the current flowing through the member changes. Then, the breakage of the impermeable sheet 1 can be detected by capturing the change in the current value.

As shown in FIG. 2, such a water-blocking sheet 1 is laid all over the bottom surface T and the slope N of the waste disposal site, but the widthwise end is sealed in advance. A required number of water sheets are joined in the width direction to cover the entire area of the waste disposal site.

The conductive member is connected to a conductive wire by a wire, and is drawn out of the waste disposal site. Each of the conductive members is connected to a measuring instrument and is monitored. Then, when the occurrence of breakage of the sheet is detected by the measuring instrument, it is possible to specify in which section the sheet has been damaged, and it is possible to start the repair work of that section.

In the present invention, an end treatment structure as shown in FIG. 1 is employed at the end 6 in the longitudinal direction of the water-blocking sheet 1. The auxiliary sheet 7 is superimposed and fused to the end 6 of the impermeable sheet 1 in a shifted state. Further, the end face 8 of the water impermeable sheet 1 is processed into a tapered shape by polishing using a grinder or the like, so that a step between the water impermeable sheet 1 and the auxiliary sheet 7 is made smooth.

Then, a fusing material 9 is applied so as to straddle the auxiliary sheet 7 of the impermeable sheet 1 and cover the end face 8. The fusion material 9 is heated and melted by an extruder, for example.
Are sequentially arranged while extruding.

If the end surface 8 of the water-blocking sheet and the auxiliary sheet 7 are at a right angle, sufficient pressure is not applied to the fusing material 9 and a gap is easily formed between the end surface 8 and the auxiliary sheet 7.
The end face 8 cannot be completely covered. The end face 8 is completely covered with the fusion material 9 and the conductive member 3
In order to prevent water from penetrating into the end face, it is preferable that the end face 8 be completely covered as much as possible,
For that purpose, it can be said that it is preferable to process the end face 8 into a tapered shape as described above. Further, since the end face 8 is roughened by processing with a grinder, the fusion strength of the fusion material 9 can be increased by the anchor effect.

The fusible material 9 is applied to the end face 8 of the impermeable sheet 1.
One important purpose is to cover and seal, but when the water-blocking sheet 1 and the auxiliary sheet 7 are separated from each other, the fusion material 9 is also simultaneously separated from the end face 8 of the water-blocking sheet. Therefore, it can be said that it is preferable that the water shielding sheet 1 and the auxiliary sheet 7 are also fused to the fusion material 9 with some strength. for that purpose,
It is preferable that a margin of fusion of the fusion material 9 to the water shielding sheet 1 and the auxiliary sheet 7 has a width of about 10 to 50 mm.

If the margin for fusion is less than 10 mm, sufficient fusion strength cannot be obtained, and the possibility of peeling increases. Even if it exceeds 50 mm, the width is excessively large in view of workability and economy. Is not preferable because it is only widened.

The water impermeable sheet 1 that can be used in the present invention
The material is preferably a thermoplastic material so that the fusion material 9 can be fused well. Specific examples include materials such as an olefin-based thermoplastic elastomer having a thickness of about 1.0 to 3.0 mm, polypropylene, polyethylene, and polyvinyl chloride. As the conductive member 3 to be embedded, polyester fiber, polyamide fiber, Conductive wires woven into a base fabric made of organic fibers such as cotton or inorganic fibers such as glass fibers, or a material in which the yarn constituting a part of the base fabric is covered or embedded with carbon or metal It can also be used.

The fusible material 9 is, of course, a thermoplastic material, and examples thereof include olefin-based thermoplastic elastomers, polypropylene, polyethylene, polyvinyl chloride, and the like. It is preferable to use the same material.

The auxiliary sheet 7 is conveniently used to cover the end surface 8 of the water-impermeable sheet while extruding the fusion material 9 on site by an extruder or the like. It must be possible, and it is preferable that sufficient fusion strength be obtained. Therefore, similar to the water-blocking sheet 1 and the fusing material 9, a material that can use an olefin-based thermoplastic elastomer, polypropylene, polyethylene, polyvinyl chloride, or the like having a thickness of about 1.0 to 2.0 mm is used. It is preferable to use the same material as the material of the fusion bonding material 9.

By adopting the above-described configuration, the end face 8 of the impermeable sheet can be reliably sealed, and can be continuously sealed for a long period of time. Next, a water pressure resistance test was performed using the example of the present invention and a comparative example deviating from the present invention, and the results were compared.

[0033]

EXAMPLE A 2.0 mm-thick olefin-based thermoplastic elastomer sheet was used as a water-shielding sheet. In the water-shielding sheet, a part of a base fabric made of polyester was covered with copper. A member provided with conductivity is embedded as a conductive member. An auxiliary sheet having a width of 100 mm made of an olefin-based thermoplastic elastomer having a thickness of 1.5 mm is displaced so as to protrude from an end of the water-impermeable sheet so as to protrude from the end of the water-impermeable sheet,
The impermeable sheet and the auxiliary sheet were fused using a hot air blower. Next, the end of the water-impervious sheet is polished with a grinder and processed into a tapered shape, and while extruding a fusible material made of an olefin-based thermoplastic elastomer with an extrusion fusing machine, the end of the water-impervious sheet is interposed between the water-impervious sheet and the auxiliary sheet. It was applied to the end face of the water sheet. The margin of fusion of the fusion material with the impermeable sheet and auxiliary sheet is 30mm
And

The test sample obtained as described above was placed in a water-resistant test tank, which was hermetically sealed, poured into the tank, filled with water, and repeatedly pressurized for 4 days in the following pressurization pattern. The pressure pattern is
0.1MPa pressurization for 8 hours continuously for 1 day
No pressure was applied for 6 hours.

Thereafter, a thumbtack is inserted into the sample, and DC
The insulation resistance between the two pushpins was measured using a 500 V insulation resistance meter. If the resistance was sufficiently high (500 MΩ or more), the sealing was completed, and if the resistance was low, water was submerged. Confirmation was made based on criteria. Table 1 shows the results.

(Comparative example 1)
The same material as in the example was used except that the auxiliary sheet and the fusion material were not used and ultrasonic sealing was performed. A water pressure resistance test was performed on the test sample in the same manner as in the example. Table 1 shows the results.

(Comparative Example 2) Example 1 was repeated except that after sealing the water-impervious sheet and the auxiliary sheet, the end face of the water-impervious sheet and the auxiliary sheet were heat-pressed and the end face was sealed without using a fusion material. The same one was used. A water pressure resistance test was performed on the test sample in the same manner as in the example. Table 1 shows the results.

(Comparative Example 3) The same material as in the example was used except that a primer was applied to the end face of the water-impervious sheet and sealed with a urethane sealing material without using a fusion material and an auxiliary sheet. A water pressure resistance test was performed on the test sample in the same manner as in the example. Table 1 shows the results.

(Comparative Example 4) The same material as that of the example was used except that the sealing material was sealed with an epoxy sealing material without using a fusing material and an auxiliary sheet, but applying a primer to the end surface of the water-blocking sheet. . A water pressure resistance test was performed on the test sample in the same manner as in the example. Table 1 shows the results.

(Comparative Example 5) After laminating the water-blocking sheet and the auxiliary sheet, a sealing material made of butyl rubber is applied to the end of the water-blocking sheet and over the auxiliary sheet without using any fusing material, and the end face is sealed. Except for the treatment, the same one as in the example was used. A water pressure resistance test was performed on the test sample in the same manner as in the example. Table 1 shows the results.

After sealing the end faces in the examples and comparative examples 1 to 5, it was determined whether or not heat fusion between the ends was possible.

[0042]

[Table 1]

From the results in Table 1, it can be seen that the insulation resistance values of Comparative Examples 1 to 3 and 5 are low, and that water has penetrated into the conductive member in the water-impermeable sheet by the water pressure resistance test. In Comparative Example 4, although water did not occur, it was difficult to bond the sheets after the end portions were treated because the sealing material itself could not be heat-sealed. It has become.

[0044]

As described above, according to the first aspect of the present invention, there is provided a waterproof sheet in which a conductive material is embedded in a thermoplastic material. In the edge treatment structure of the water-impervious sheet that can be electrically detected by the heat-sealing sheet, a thermoplastic auxiliary sheet is superimposed on the end of the water-impervious sheet, and the fusion material is spread over the water-impervious sheet and the auxiliary sheet. Is disposed so as to cover the end face of the water-impermeable sheet, and the end of the water-impermeable sheet is sealed.

By arranging the auxiliary sheet on the end of the water-impervious sheet and arranging the fusible material over both sheets to cover the end face of the water-impervious sheet, the end of the water-impervious sheet is It is completely sealed and can prevent infiltration from the end face of the impermeable sheet.

According to a second aspect of the present invention, the water-impervious sheet has an end treatment structure in which an end of the water-impervious sheet is tapered to eliminate a step with the auxiliary sheet.

By smoothly connecting the end of the waterproof sheet and the auxiliary sheet, the fusing material easily covers the front surface of the end face of the waterproof sheet, and a gap is generated between the fusing material and the waterproof sheet. Can be prevented, and peeling of the fusion bonding material from the impermeable sheet can be prevented.

According to a third aspect of the present invention, the margin of the water-impervious sheet and the auxiliary sheet has an end treatment structure having a width of 10 to 50 mm, and the bonding material has sufficient strength for the water-impervious sheet and the auxiliary sheet. Therefore, there is no need to worry about peeling of the fusion material, and it is possible to prevent the problem of water seepage into the water-impermeable sheet.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing an edge treatment structure of a water-blocking sheet of the present invention.

FIG. 2 is a schematic perspective view showing a state where a waterproof sheet is laid at a waste disposal site.

FIG. 3 is a plan view of a conductive member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waterproof sheet 2 Elastomer 3 Conductive member 4 Base cloth 5 Conducting wire 6 End part 7 Auxiliary sheet 8 End face 9 Fusing material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B29L 9:00 B29L 9:00 F term (reference) 4D004 AA46 BB05 BB06 4F100 AB01B AB17B AK01A AK01C AK03A AK03C AK41B AK45B AL09A AL09C AR00B BA03 BA06 BA10A BA10C DB05 DB06 DG01B DG17B GB90 JB16A JB16C JG01B 4F211 AA03 AA45 AC03 AD05 AD08 AD20 AG01 AH01 AH43 SA17 SC09 SD02 SG01 SJ29

Claims (3)

[Claims] An impermeable sheet having a conductive material embedded in a thermoplastic material, wherein water infiltration due to breakage of the impermeable sheet can be electrically detected using the electroconductive member. In the sheet edge treatment structure, a thermoplastic auxiliary sheet is superimposed on the end of this water-impervious sheet, and a fusion material is applied to cover the end face of the water-impervious sheet so as to straddle the water-impervious sheet and the auxiliary sheet. An end treatment structure for a water-impervious sheet, which is disposed and the end of the water-impervious sheet is sealed. 2. The end treatment structure for a water-impervious sheet according to claim 1, wherein the end surface of the water-impervious sheet is tapered to eliminate a step with the auxiliary sheet. 3. The end treatment structure for a water-impervious sheet according to claim 1, wherein the margin for fusing the water-impervious sheet and the auxiliary sheet has a width of 10 to 50 mm.