Waterproofing structure and waterproofing method

Abstract

During the construction of the waterproof structure, the waterproofing performance of the waterproof sheet surrounding the protruding object is confirmed by a spark test. [Solution] The waterproofing structure 1 comprises a waterproofing sheet with a first conductive layer 2, in which a first conductive layer 20 is laminated and integrated with a first waterproofing sheet 21, and a waterproofing sheet with a second conductive layer 3, in which a second conductive layer 30 is laminated and integrated with a second waterproofing sheet 31. The waterproofing sheet with the first conductive layer 2 has through holes 2a for inserting protrusions, and is positioned relative to the laying surface so that the first conductive layer 20 is on the laying surface side. The waterproofing sheet with the second conductive layer 3 includes a first portion 3a and a second portion 3b connected to the first portion 3a. The first portion 3a is positioned to cover the entire outer surface of a protrusion so that the second conductive layer 30 is on the protrusion side. The second portion 3b is folded relative to the first portion 3a so as to conform to the laying surface, and is positioned on the waterproofing sheet with the first conductive layer 2 so that the second conductive layer 30 is on the laying surface side.

Description

[[Technical Field]]

[0001] The present invention relates to a water-blocking structure and a water-blocking construction method that are laid for a water-blocking target structure having a laying surface and a protruding object such as a communication pipe protruding from the laying surface. [[Background Art]]

[0002] Conventionally, soft water-blocking sheets made of synthetic resin or rubber have been laid to install artificial water-blocking layers for waste disposal sites or general civil engineering works. Although this type of water-blocking sheet is easy to lay and excellent in economic efficiency, small holes of about 0.1 mm, that is, pinholes, may occur due to damage during storage before shipment from the factory, transportation to the construction site, or laying construction at the site. Furthermore, there is also a risk of poor joining between water-blocking sheets. Since such pinholes and poor joining can lead to water leakage, it is necessary to conduct an inspection to confirm the water-blocking performance (watertightness) during construction. As specific construction management, after laying the water-blocking sheets, inspections are carried out by methods such as pressure inspection, vacuum inspection, and spark inspection.

[0003] Pressure inspection is a method in which an inspection space is formed at the joint of two water-blocking sheets, both ends of the inspection space are closed with end closing fasteners to form a sealed space, the inspection space is pressurized with a pump or the like, and if the pressure in the inspection space is maintained for a predetermined time, the joining state of the joint is judged to be good.

[0004] Vacuum inspection is a method in which soapy water is applied to the joint of two water-blocking sheets, a negative pressure capsule is placed over the joint of a predetermined length to form a sealed space, and if no bubbles of soapy water are generated when the sealed space is set to negative pressure, the joining is judged to be good, and if bubbles are generated, the joining is judged to be defective.

[0005] Spark testing, as described in Patent Documents 1 and 2, involves placing a conductive layer (e.g., electrically conductive nonwoven fabric) beneath a waterproof sheet (e.g., a vulcanized rubber sheet, a polyethylene sheet), pressing the waterproof sheet against the conductive layer with a sheet-holding member to ensure close contact, and then arranging an electrode brush along the contact area of ​​the waterproof sheet to detect pinholes. If a pinhole exists, current flows between the electrode brush and the conductive layer, generating a spark. By electrically detecting the spark, it is possible to confirm whether or not there are defects (pinholes) in the waterproof sheet. Spark testing is particularly useful for detecting damage that is difficult to see, such as small holes (pinholes) in waterproof sheets. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 3710840 [Patent Document 2] Patent No. 6087656 [Overview of the project] [Problems that the invention aims to solve]

[0007] In waste disposal sites, as well as reservoirs and ponds that store water from rivers or rainwater, a waterproof sheet is laid over the entire surface, and water is discharged to the outside or drawn in from the outside through connecting pipes that connect the inside and outside of the sheet. In waste disposal sites, drainage pipes that discharge accumulated water to the outside are installed as connecting pipes, with a portion of them embedded in the walls of the disposal site. Such connecting pipes, such as drainage pipes, are protruding objects that extend from the surface (wall) where the waterproof sheet is laid, and corners are created at the connection points between the surface and the connecting pipes. When there are connecting pipes on the surface where the waterproof sheet is laid, through holes are formed in the waterproof sheet, and the connecting pipes are inserted through these through holes. In this waterproof structure, at the corners between the surface and the connecting pipes, the outer surface of the connecting pipe and the edge of the through hole in the waterproof sheet are joined with adhesive. In such a waterproof structure, pinholes or poorly joined waterproof sheets around protruding objects can lead to water leakage, so it is necessary to check the waterproof performance around the protruding objects during construction.

[0008] However, the pressure and vacuum tests described above are performed on waterproof sheets laid on flat surfaces. Therefore, these methods cannot be applied to structures where protrusions such as connecting pipes protrude from the surface on which the waterproof sheet is laid. Furthermore, in the case of a waterproof structure in which the outer surface of a protrusion is joined to the edge of a through-hole in the waterproof sheet, the edge of the waterproof sheet will be positioned at the corner between the laid surface and the protrusion. Pinholes in the waterproof sheet formed at such corners are difficult to detect by spark testing. For this reason, in the case of the waterproof structure described above, it is difficult to inspect the waterproof sheet around the protrusion even with the spark testing method.

[0009] Therefore, the object of the present invention is to provide a waterproof structure and waterproof construction method that allows the waterproofing performance of the waterproof sheet around a protruding object to be confirmed by spark testing during the construction of the waterproof structure. [Means for solving the problem]

[0010] To solve the above problems, the present invention provides a waterproofing structure to be laid on a waterproofing target structure having a laying surface and a protrusion protruding from the laying surface, comprising a waterproofing sheet with a first conductive layer in which a first conductive layer is laminated and integrated with a first waterproofing sheet, and a waterproofing sheet with a second conductive layer in which a second conductive layer is laminated and integrated with a second waterproofing sheet, wherein the waterproofing sheet with the first conductive layer has a through hole for inserting the protrusion and is arranged on the laying surface such that the first conductive layer is on the laying surface side, and the waterproofing sheet with the second conductive layer includes a first portion and a second portion connected to the first portion, wherein the first portion is arranged to cover the entire outer surface of the protrusion such that the second conductive layer is on the protrusion side, and the second portion is bent relative to the first portion so as to be along the laying surface and is arranged on the waterproofing sheet with the first conductive layer such that the second conductive layer is on the laying surface side.

[0011] According to the above configuration, since the waterproof sheet with the first conductive layer is placed around the protrusion, the waterproofing performance of the waterproof sheet around the protrusion can be confirmed by performing a spark test on the waterproof sheet with the first conductive layer. In addition, the waterproof sheet with the second conductive layer is placed across the corner between the laying surface and the protrusion. Therefore, the waterproofing performance of the waterproof sheet at the corner between the laying surface and the protrusion can be confirmed by performing a spark test on the waterproof sheet with the second conductive layer. Thus, when constructing the waterproofing structure, the waterproofing performance of the waterproof sheet around the protrusion, including the corner between the laying surface and the protrusion, can be fully confirmed by spark testing.

[0012] Furthermore, the water-blocking structure of the present invention may further include a water-blocking cover sheet having a through hole for inserting the protrusion and arranged to cover at least the second portion of the water-blocking sheet with the second conductive layer. Here, the second portion of the water-blocking sheet with the second conductive layer is a structurally weak part, and there is a risk that in the future, due to impact or deterioration over time, the second portion may peel off or be damaged, reducing the water-blocking performance. With the above configuration, since the second portion is covered by the water-blocking cover sheet, the possibility of a decrease in the water-blocking performance of the water-blocking structure in the future can be reduced.

[0013] Furthermore, in the water-blocking structure of the present invention, the water-blocking cover sheet may be arranged to cover not only the second portion of the water-blocking sheet with the second conductive layer, but also at least a portion of the water-blocking sheet with the first conductive layer. With the above configuration, the possibility of a decrease in the water-blocking properties of the water-blocking structure in the future can be further reduced.

[0014] Furthermore, in the water-blocking structure of the present invention, the first conductive layer-equipped water-blocking sheet, the second conductive layer-equipped water-blocking sheet, and the water-blocking cover sheet may be considered as one set, and multiple sets may be laminated on the water-blocking target structure. With the above configuration, the water-blocking properties of the water-blocking structure can be further improved.

[0015] Furthermore, in the water-blocking structure of the present invention, the shape and size of the through-hole in the water-blocking sheet with the first conductive layer may be at least one of the following: a shape and size such that the gap between the edge of the through-hole and the outer contour of the protrusion is 20 mm or less; a shape and size such that the gap between the edge of the through-hole and the outer contour of the protrusion is 10% or less of the diameter of the through-hole; or a shape and size such that 50% or more of the entire circumference of the through-hole is in contact with the outer surface of the protrusion. According to the above configuration, the possibility of a gap that causes water leakage occurring at the boundary between the edge of the through-hole in the water-blocking sheet with the first conductive layer and the outer surface of the protrusion can be reduced.

[0016] Furthermore, the waterproofing step of the present invention is a waterproofing method for laying a waterproofing structure on a waterproofing target structure having a laying surface and a protrusion protruding from the laying surface, the first placement step is to place a waterproofing sheet with a first conductive layer in which a first conductive layer is laminated and integrated with a first waterproofing sheet, the first placement step is to insert the protrusion through a through hole formed in the waterproofing sheet with the first conductive layer and to place the waterproofing sheet with the first conductive layer on the laying surface with the first conductive layer facing the laying surface, and the second conductive layer is laminated on the second waterproofing sheet A second arrangement step for arranging a waterproof sheet with an integrated second conductive layer, comprising: arranging a first portion of the waterproof sheet with the second conductive layer so as to cover the entire outer surface of the protrusion with the second conductive layer facing the protrusion; and bending the second portion connected to the first portion of the waterproof sheet with the second conductive layer relative to the first portion so as to follow the laying surface, and arranging it on the waterproof sheet with the first conductive layer with the second conductive layer facing the laying surface.

[0017] According to the above configuration, since the waterproof sheet with the first conductive layer is placed around the protrusion, the waterproofing performance of the waterproof sheet around the protrusion can be confirmed by performing a spark test on the waterproof sheet with the first conductive layer. In addition, the waterproof sheet with the second conductive layer is placed across the corner between the laying surface and the protrusion. Therefore, the waterproofing performance of the waterproof sheet at the corner between the laying surface and the protrusion can be confirmed by performing a spark test on the waterproof sheet with the second conductive layer. Thus, when constructing the waterproofing structure, the waterproofing performance of the waterproof sheet around the protrusion, including the corner between the laying surface and the protrusion, can be fully confirmed by spark testing.

[0018] Further, in the water blocking step of the present invention, there are provided: an inspection step of inspecting the water blocking performance of the first water blocking sheet with a conductive layer arranged in the first arrangement step and the second water blocking sheet with a conductive layer arranged in the second arrangement step by spark inspection; and a third arrangement step of arranging a water-blocking cover sheet after the inspection step, the third arrangement step including inserting the protrusion through a through-hole formed in the water-blocking cover sheet and arranging the water-blocking cover sheet so as to cover at least the second portion of the second water blocking sheet with a conductive layer, and the method may further include these steps. Here, since the second portion of the second water blocking sheet with a conductive layer is a structurally fragile part, there is a risk that the second portion may peel off or be damaged under the influence of impact, aging degradation or the like in the future, resulting in a decrease in water blocking performance. According to the above configuration, after the inspection step, the second portion is covered with the water-blocking cover sheet in the third arrangement step, so that the possibility of the water blocking performance of the water blocking structure decreasing in the future can be reduced. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a water blocking structure and a water blocking construction method that enable confirmation of the water blocking performance of a water blocking sheet around a protrusion by spark inspection when the water blocking structure is constructed. [Brief Description of Drawings]

[0020] [Figure 1] It is a cross-sectional view of a waste disposal site. [Figure 2] It is a cross-sectional view of the water blocking structure according to an embodiment of the present invention. [Figure 3] It is a diagram showing a state in the middle of construction of the water blocking structure, where (a) is a perspective view and (b) is a cross-sectional view. [Figure 4] It is a diagram showing a state in the middle of construction of the water blocking structure, where (a) is a perspective view and (b) is a cross-sectional view. [Figure 5] It is a diagram showing a state in the middle of construction of the water blocking structure, where (a) is a perspective view and (b) is a cross-sectional view. [Figure 6] It is a diagram showing a state in the middle of construction of the water blocking structure, where (a) is a perspective view and (b) is a cross-sectional view. [Figure 7] It is a cross-sectional view of a water blocking structure according to a modified example. MODE FOR CARRYING OUT THE INVENTION

[0021] (Configuration of Waste Disposal Site 100) Prior to describing the configuration of the water blocking structure 1 according to the present embodiment, a waste disposal site 100 to which the water blocking structure 1 is applied will be described.

[0022] As shown in FIG. 1, the waste disposal site 100 includes a recess 101 formed in the ground and a communication pipe 102. Most of the recess 101 is formed of concrete. The recess 101 has a rectangular opening and a rectangular bottom surface 101a, and a side surface 101b connected to the bottom surface 101a. Further, the recess 101 is configured such that the size of the opening is larger than the size of the bottom surface 101a, and has a trapezoidal shape in vertical cross-section. The side surface 101b of the recess 101 has a vertical cross-section that forms a linear slope inclined from the inner side to the outer side of the recess 101 as it goes from the bottom surface 101a of the recess 101 toward the opening. Note that the shape of the recess 101 is not limited to this, and may be appropriately set according to the waste disposal site. For example, in FIG. 1, the bottom surface 101a of the recess 101 is a flat surface, but it may be a slope.

[0023] The communication pipe 102 functions as a collection and drainage pipe, and is embedded in the side wall of the recess 101 such that one end thereof is exposed into the recess 101. Water accumulated in the recess 101 is discharged to the outside through the communication pipe 102. The communication pipe 102 is a circular pipe. The communication pipe 102 is disposed on the side surface 101b that is a slope near the bottom surface 101a of the recess 101. The end of the communication pipe 102 exposed inside the recess 101 is connected to a perforated collection and drainage pipe 103 having a plurality of holes formed on its side surface. Although not illustrated, the periphery of the perforated collection and drainage pipe 103 is covered with crushed stone or cobble stone. A drainage pipe 104 is connected to the other end of the communication pipe 102, and this drainage pipe 104 extends to a sewage treatment facility provided outside the waste disposal site.

[0024] The connecting pipe 102 is made of thermoplastic resin. While it is preferable to use polyethylene pipe, which has excellent pressure resistance, for the connecting pipe 102, it is not limited to this. The connecting pipe 102 may also be made of, for example, polyvinyl chloride resin. The diameter and length of the connecting pipe 102 are appropriately set according to the waste disposal site.

[0025] In the waste disposal site 100, a waterproof structure is laid on the bottom surface 101a and side surface 101b of the recess 101, but the configuration of the waterproof structure differs depending on where it is laid. Specifically, the waterproof structure 1 according to this embodiment is laid around the connecting pipe 102, and the waterproof structure 200 is laid in the other parts. The waterproof structure 1 and the waterproof structure 200 have different layer structures.

[0026] The waterproofing structure 200 is laid on a waterproofing target structure that has the bottom surface 101a of the recess 101 and the portion of the side surface 101b of the recess 101 other than the area around the connecting pipe 102. That is, the waterproofing structure 200 is laid on a flat waterproofing target structure without irregularities. In contrast, the waterproofing structure 1 is laid on a waterproofing target structure that has a side surface 101b which is the laying surface and a connecting pipe 102 which is a protrusion that extends from the side surface 101b.

[0027] (Composition of the waterproof structure 200) The following describes a waterproof structure 200 laid on a flat waterproof structure. The waterproof structure 200 comprises a lower protective mat 201, a waterproof sheet 202, and an upper protective mat 203, which are laminated in this order on the bottom surface 101a and side surface 101b of the recess 101 that serves as the laying surface of the waterproof structure.

[0028] The lower protective mat 201 and the upper protective mat 203 are protective mats common to the waterproof structure 1 and the waterproof structure 200. The lower protective mat 201 is placed on the entire surface of the recess 101, excluding the connecting pipe 102, and is fixed to the recess 101 by fasteners (not shown) embedded in the recess 101. The lower protective mat 201 also has a through hole through which the connecting pipe 102 is inserted. The upper protective mat 203 is placed on the entire surface of the recess 101, excluding the connecting pipe 102, and on a part of the outer circumferential surface of the connecting pipe 102, and is fixed to the connecting pipe 102 by bands (not shown) attached to the outer circumferential surface of the connecting pipe 102. The upper protective mat 203 also has a through hole through which the connecting pipe 102 is inserted.

[0029] The protective mats 201 and 203 are made of synthetic resins such as polyester, acrylic, polypropylene, and polyethylene. The protective mats 201 and 203 can take the form of nonwoven fabric, woven fabric, foam, a laminate of nonwoven fabric and a resin sheet, a laminate of nonwoven fabric and a foam, or a laminate of foam and a resin sheet. The thickness of the protective mats 201 and 203 is, for example, about 3 to 20 mm. By arranging these protective mats 201 and 203 with the waterproof sheet 202 sandwiched between them, the possibility of damage to the waterproof sheet 202 can be reduced.

[0030] The waterproof sheet 202 is made of rubber or thermoplastic resin. Specifically, for example, EPDM (ethylene propylene rubber), HDPE (high-density polyethylene), LDPE (low-density polyethylene), VLDPE (very low-density polyethylene), LLDPE (linear low-density polyethylene), PP (polypropylene), TPE (thermoplastic elastomer), etc. are used. The thickness of the waterproof sheet 202 is, for example, about 0.5 to 3.0 mm, which is thinner than the thickness of the protective mats 201 and 203. The lower protective mat 201 and the waterproof sheet 202 are joined together by a fusion material made of a thermoplastic resin such as polyethylene. Similarly, the waterproof sheet 202 and the upper protective mat 203 are joined together by a fusion material. In addition, rectangular holes 202a are formed in the waterproof sheet 202 around the connecting pipe 102 on which the waterproof structure 1 is laid (see Figures 2 and 3(a)).

[0031] (Configuration of waterproof structure 1) Next, we will describe the waterproofing structure 1 laid around the connecting pipe 102 according to this embodiment.

[0032] As shown in Figure 2, the water-blocking structure 1 comprises a lower protective mat 201, a water-blocking sheet 2 with a first conductive layer, a water-blocking sheet 3 with a second conductive layer, a water-blocking cover sheet 4, and an upper protective mat 203.

[0033] As described above, the lower protective mat 201 and the upper protective mat 203 are protective mats common to the waterproof structure 1 and the waterproof structure 200. The lower protective mat 201 is laid not only on the laying surface of the waterproof structure 200, but also continuously and integrally on the side surfaces 101b around the connecting pipe 102 of the waterproof structure 1. The upper protective mat 203 is laid not only on the laying surface of the waterproof structure 200, but also continuously and integrally on the side surfaces 101b around the connecting pipe 102 of the waterproof structure 1 and on a part of the outer surface of the connecting pipe 102.

[0034] The first conductive layer-equipped waterproof sheet 2 is a sheet in which the first conductive layer 20 is laminated and integrated with the first waterproof sheet 21. Similarly, the second conductive layer-equipped waterproof sheet 3 is a sheet in which the second conductive layer 30 is laminated and integrated with the second waterproof sheet 31. The thickness of the conductive layer-equipped waterproof sheets 2 and 3 is, for example, 1.5 mm.

[0035] The conductive layers 20 and 30 are electrically conductive layers and are formed from, for example, a woven or nonwoven fabric attached to the surface of aluminum foil, a conductive nonwoven fabric containing carbon-infused fibers, a conductive nonwoven fabric using fibers chemically formed from polypyrrole, an electron-conjugated conductive polymer, or a conductive nonwoven fabric using fibers produced by treating acrylic fibers with a compound containing a divalent copper compound and sulfur.

[0036] The waterproof sheets 21 and 31 are formed from rubber or thermoplastic resin, similar to the waterproof sheet 202 described above. Specifically, they are formed from vulcanized rubber, polyethylene, etc.

[0037] The waterproof sheet 2 with the first conductive layer is positioned relative to the laying surface with the first conductive layer 20 facing the laying surface side (side 101b side). In this embodiment, the waterproof sheet 2 with the first conductive layer is positioned on the lower protective mat 201 laid on the laying surface.

[0038] A circular through-hole 2a is formed in the center of the waterproof sheet 2 with the first conductive layer, through which the connecting pipe 102 is inserted. The shape and size of the through-hole 2a are approximately the same as the shape and size of the outer contour of the connecting pipe 102 (the outer contour of the part that is joined to the edge of the through-hole 2a). Specifically, the through-hole 2a is circular in shape corresponding to the outer contour of the connecting pipe 102, and its diameter is approximately the same as the diameter of the connecting pipe 102. In this invention and embodiment, "approximately the same" is not limited to cases where they are exactly the same, but includes cases where the difference is slight. Specifically, the shape and size of the through-hole 2a are sufficient if they satisfy at least one of the following first, second, and third conditions.

[0039] The first condition is that the gap between the edge of the through-hole 2a and the outer contour of the connecting pipe 102 (the gap at the joint between the edge of the through-hole 2a and the outer surface of the connecting pipe 102) is 20 mm or less. For example, if the difference between the diameter of the through-hole 2a and the diameter of the connecting pipe 102 is 20 mm or less, the above gap will be 20 mm or less, and therefore this condition is met.

[0040] The second condition is that the gap between the edge of the through-hole 2a and the outer contour of the connecting pipe 102 is 10% or less of the diameter of the through-hole 2a.

[0041] The third condition is that 50% or more of the entire circumference of the through hole 2a is in contact with the outer surface of the connecting pipe 102.

[0042] The shape and size of the through-hole 2a only need to satisfy at least one of the three conditions described above (the first, second, and third conditions), and may satisfy two or all three conditions. Furthermore, as long as at least one of the three conditions is satisfied, the diameter of the through-hole 2a may be smaller than the diameter of the connecting pipe 102. For example, the diameter of the through-hole 2a may be about 20 mm (10% of the diameter) smaller than the diameter of the connecting pipe 102.

[0043] The edge of the through-hole 2a in the first conductive layer-equipped waterproof sheet 2 and the outer surface of the connecting pipe 102 are joined by a fusion material or the like. As described above, by making the shape and size of the through-hole 2a approximately the same as the shape and size of the outer contour of the connecting pipe 102, and by joining the edge of the through-hole 2a and the outer surface of the connecting pipe 102 with a fusion material or the like, the boundary between the edge of the through-hole 2a and the outer surface of the connecting pipe 102 can be sealed without any gaps.

[0044] The outer edge 2b of the waterproof sheet 2 with the first conductive layer is superimposed on the edge of the rectangular hole 202a of the waterproof sheet 202 of the waterproof structure 200 and joined by a fusion material or the like.

[0045] The waterproof sheet 3 with the second conductive layer includes a first portion 3a and a second portion 3b connected to the first portion 3a. The first portion 3a has a cylindrical shape and is positioned to cover the entire outer surface of the connecting pipe 102 so that the second conductive layer 30 faces the connecting pipe 102. The outer edge of the first portion 3a is joined to the outer surface of the connecting pipe 102 by a fusion material or the like. The outer edge of the first portion 3a may also be further fixed to the outer surface of the connecting pipe 102 by a SUS band or sealing material.

[0046] The second portion 3b is bent relative to the first portion 3a so as to conform to the side surface 101b which will be the laying surface of the recess 101, and is positioned on the waterproof sheet 2 with the first conductive layer so that the second conductive layer 30 faces the side surface 101b (laying surface side). The second portion 3b is positioned to surround the perimeter of the connecting pipe 102. By positioning the first portion 3a and the second portion 3b as described above, the waterproof sheet 3 with the second conductive layer is positioned to straddle the corner between the side surface 101b and the connecting pipe 102, and the edge of the waterproof sheet 3 with the second conductive layer is not positioned at the corner.

[0047] The second portion 3b has multiple notches 3b1 directed toward the center of the connecting pipe 102 (see Figure 5(a)). The multiple notches 3b1 of the second portion 3b are formed by making cuts toward the center of the connecting pipe 102 from multiple positions in the circumferential direction of the outer edge of the cylindrical waterproof sheet 3 with the second conductive layer, which becomes the second portion 3b connected to the first portion 3a. The length of the notches 3b1 is, for example, 10 cm. These multiple notches 3b1 make it easier to align (closely adhere to) the second portion 3b on the waterproof sheet 2 with the first conductive layer.

[0048] Furthermore, the U-shaped outer edge of the second portion 3b formed by the cut 3b1 is joined to the first conductive layer-equipped water-blocking sheet 2 by a fusion material or the like.

[0049] The water-impermeable cover sheet 4 is formed of rubber or thermoplastic resin, similar to the water-impermeable sheet 202 described above.

[0050] A circular through-hole 4a is formed in the center of the water-impermeable cover sheet 4, through which the connecting pipe 102 is inserted. The shape and size of the through-hole 4a are approximately the same as the shape and size of the outer contour of the first portion 3a of the water-impermeable sheet 3 with the second conductive layer (the outer contour of the portion joined to the edge of the through-hole 4a). That is, the diameter of the through-hole 4a is approximately the same as the outer diameter of the first portion 3a. In this invention and embodiment, "approximately the same" is not limited to cases where they are exactly the same, but includes cases where the difference is slight. Therefore, the diameter of the through-hole 4a may be slightly larger than the outer diameter of the first portion 3a.

[0051] The size of the water-impermeable cover sheet 4 is smaller than or about the same as the size of the water-impermeable sheet 2 with the first conductive layer. The water-impermeable cover sheet 4 is arranged to cover at least a portion of the water-impermeable sheet 2 with the first conductive layer and the second portion 3b of the water-impermeable sheet 3 with the second conductive layer. In this embodiment, the water-impermeable cover sheet 4 is arranged to cover the portion of the water-impermeable sheet 2 with the first conductive layer other than the outer edge portion 2b and the second portion 3b of the water-impermeable sheet 3 with the second conductive layer. The outer edge portion of the water-impermeable cover sheet 4 is joined to the water-impermeable sheet 2 with the first conductive layer using a fusion material or the like. The edge portion of the through hole 4a of the water-impermeable cover sheet 4 is joined to the water-impermeable sheet 3 with the second conductive layer using a fusion material or the like.

[0052] (Waterproofing method) The following describes the waterproofing method for forming the waterproofing structure 1. In this embodiment 1, the waterproofing structure 1 is not formed in advance at a factory, workshop, or other location other than the waste disposal site 100 and brought to the construction site, but is formed at the construction site.

[0053] First, the lower protective mat 201 is laid on the side surface 101b and bottom surface 101a (see Figure 1) of the recess 101. Also, as shown in Figures 3(a) and 3(b), the waterproof sheet 202 of the waterproof structure 200 is laid on the lower protective mat 201 on the bottom surface 101a and on the side surface 101b of the recess 101, excluding the area around the connecting pipe 102. The waterproof sheet 202 has rectangular holes 202a formed in the area where the waterproof structure 1 is laid.

[0054] Next, as shown in Figures 4(a) and 4(b), a first placement step is performed in which the waterproof sheet 2 with the first conductive layer is placed on the laying surface. Specifically, the connecting pipe 102 is inserted through the through hole 2a formed in the waterproof sheet 2 with the first conductive layer, and the waterproof sheet 2 with the first conductive layer is placed on the laying surface with the first conductive layer 20 facing the side surface 101b that will be the laying surface. In this embodiment, the waterproof sheet 2 with the first conductive layer is placed on the lower protective mat 201 laid on the laying surface. At this time, the edge of the through hole 2a of the waterproof sheet 2 with the first conductive layer and the outer surface of the connecting pipe 102 are joined together with a fusion material or the like. In addition, the outer edge 2b of the waterproof sheet 2 with the first conductive layer is overlapped with the edge of the rectangular hole 202a of the waterproof sheet 202 of the waterproof structure 200 and joined together with a fusion material or the like. At this time, in order to connect the cathode of the inspection machine 82 described later with the first conductive layer 20, a portion of the outer edge 2b of the waterproof sheet 2 with the first conductive layer is left unjoined, without being joined to the edge of the hole 202a.

[0055] Next, as shown in Figures 5(a) and 5(b), a second placement step is performed in which the waterproof sheet 3 with the second conductive layer is placed. Specifically, first, multiple cuts 3b1 are made at one end of the cylindrical waterproof sheet 3 with the second conductive layer, from its outer edge toward the first portion 3a, to form a first portion 3a and a second portion 3b having multiple cuts 3b1 connected to the first portion 3a. Then, the first portion 3a of the waterproof sheet 3 with the second conductive layer is placed with the second conductive layer 30 facing the connecting pipe 102, so as to cover the entire outer surface of the connecting pipe 102. Also, the second portion 3b of the waterproof sheet 3 with the second conductive layer is bent relative to the first portion 3a so as to follow the side surface 101b which will be the laying surface, and placed on the waterproof sheet 2 with the second conductive layer 30 facing the side surface 101b.

[0056] The outer edge of the first portion 3a at the other end of the cylindrical waterproof sheet 3 with the second conductive layer is joined to the outer surface of the connecting pipe 102 by a fusion material or the like. In addition, the U-shaped outer edge formed by the cut 3b1 in the second portion 3b is joined to the waterproof sheet 2 with the first conductive layer by a fusion material or the like. At this time, in order to allow the cathode of the inspection machine 82 described later to be connected to the second conductive layer 30, a part of the U-shaped outer edge of the second portion 3b is left unjoined from the waterproof sheet 2 with the first conductive layer.

[0057] After the second placement process, a spark inspection is performed to confirm the watertightness (waterproofness) of the first conductive layer-equipped waterproof sheet 2 and the second conductive layer-equipped waterproof sheet 3. Here, since the first conductive layer-equipped waterproof sheet 2 and the second conductive layer-equipped waterproof sheet 3 are soft sheets, there is a risk of damage such as pinholes occurring at any point around the connecting pipe 102. For this reason, in the inspection process, the watertightness of the waterproof sheets 21 and 31 around the connecting pipe 102 is confirmed by a spark inspection. This spark inspection is performed using a spark inspection device 80.

[0058] Specifically, as shown in Figure 5(b), the spark inspection device 80 comprises an electrode brush 81 and an inspection machine 82. When checking the water-impermeability of the first conductive layer-equipped waterproof sheet 2, the cathode of the inspection machine 82 is connected to the first conductive layer 20 of the first conductive layer-equipped waterproof sheet 2 via the unbonded portion of the outer edge 2b of the first conductive layer-equipped waterproof sheet 2. Then, with a high voltage applied to the electrode brush 81 by the inspection machine 82, the electrode brush 81 is scanned along the surface of the first conductive layer-equipped waterproof sheet 2. At this time, if there are defects such as pinholes or other damage or poor bonding in the first waterproof sheet 21 of the first conductive layer-equipped waterproof sheet 2, current flows between the electrode brush 81 and the conductive layer 20, generating a spark. Therefore, the inspection machine 82 can check the water-impermeability of the first waterproof sheet 21 by detecting the presence or absence of a spark. Once the water-impermeability of the first waterproof sheet 21 has been checked, the cathode of the inspection machine 82 is removed from the first conductive layer 20. Furthermore, the unjoined portion of the outer edge 2b of the first conductive layer-equipped water-blocking sheet 2 is joined to the edge of the hole 202a using a fusion material or the like.

[0059] When checking the water-impermeableness of the second conductive layer-equipped waterproof sheet 3, the cathode of the inspection machine 82 is connected to the second conductive layer 30 of the second conductive layer-equipped waterproof sheet 3 via the unjointed portion at the U-shaped outer edge of the second part 3b. Then, with a high voltage applied to the electrode brush 81 by the inspection machine 82, the electrode brush 81 is scanned along the surface of the second conductive layer-equipped waterproof sheet 3. The inspection machine 82 can confirm the water-impermeableness of the second waterproof sheet 31 of the second conductive layer-equipped waterproof sheet 3 by detecting the presence or absence of sparks. Once the confirmation of the water-impermeableness of the second waterproof sheet 31 is complete, the cathode of the inspection machine 82 is removed from the second conductive layer 30. Furthermore, the unjointed portion at the U-shaped outer edge of the second part 3b is joined to the first conductive layer-equipped waterproof sheet 2 using a fusion material or the like.

[0060] In this manner, the water-impermeable properties of the first conductive layer-equipped water-impermeable sheet 2 and the second conductive layer-equipped water-impermeable sheet 3 are confirmed. If defects are found in the water-impermeable sheets 21 and 31, the defective areas are repaired, and then the spark test is performed again.

[0061] After the inspection process, a third placement process is performed in which the water-impermeable cover sheet 4 is placed, as shown in Figures 6(a) and 6(b). Specifically, the connecting pipe 102 is inserted through the through hole 4a formed in the water-impermeable cover sheet 4, and the water-impermeable cover sheet 4 is placed so as to cover the portion of the first conductive layer-attached water-impermeable sheet 2 other than the outer edge 2b, and the second portion 3b of the second conductive layer-attached water-impermeable sheet 3. The outer edge of the water-impermeable cover sheet 4 is joined to the first conductive layer-attached water-impermeable sheet 2 with a fusion material or the like. The edge of the through hole 4a of the water-impermeable cover sheet 4 is joined to the second conductive layer-attached water-impermeable sheet 3 with a fusion material or the like.

[0062] After the third placement step, the upper protective mat 203 is placed over the entire surface of the recess 101. At this time, as shown in Figure 2, the upper protective mat 203 is positioned so that the connecting pipe 102 is passed through the through-holes formed in the upper protective mat 203, and the first portion 3a of the waterproof sheet 3 with the second conductive layer, which is placed on the outer surface of the connecting pipe 102, is covered over the axial direction and the entire circumference of the connecting pipe 102. Then, the upper protective mat 203 is fixed to the connecting pipe 102 by a band (not shown) attached to the outer surface of the connecting pipe 102. With this, the construction of the waterproof structure 1 is completed.

[0063] As described above, according to this embodiment, since the waterproof sheet 2 with the first conductive layer is arranged around the connecting pipe 102, the waterproofing performance around the connecting pipe 102 can be confirmed by performing a spark test on the waterproof sheet 2 with the first conductive layer.

[0064] Here, at the corner between the side surface 101b of the recess 101 and the connecting pipe 102, although the edge of the through-hole 2a of the waterproof sheet 2 with the first conductive layer is joined to the outer surface of the connecting pipe 102, there is a risk that a gap may occur between the outer surface of the connecting pipe 102 and the edge of the through-hole 2a. If such a gap occurs, there is a risk that water may leak from the waterproof sheet 2 with the first conductive layer to the side surface 101b side (substrate side), but it is difficult to confirm this gap by spark testing of the waterproof sheet 2 with the first conductive layer. Furthermore, if the waterproof sheet with the second conductive layer does not have a second portion, there is a risk that a gap may occur at the corner between the waterproof sheet with the first conductive layer and the first portion of the waterproof sheet with the second conductive layer, but it is also difficult to confirm this gap by spark testing of the waterproof sheet with the first conductive layer and the waterproof sheet with the second conductive layer.

[0065] However, in this embodiment, the waterproof sheet 3 with the second conductive layer has a first portion 3a and a second portion 3b as described above. Therefore, the waterproof sheet 3 with the second conductive layer is positioned to span the corner between the side surface 101b and the connecting pipe 102 so that the gap described above does not occur. As a result, by performing a spark test on the waterproof sheet 3 with the second conductive layer, the waterproofing performance of the waterproof sheet at the corner between the side surface 101b and the connecting pipe 102 can be confirmed. As described above, according to this embodiment, by positioning the waterproof sheet 2 with the first conductive layer and the waterproof sheet 3 with the second conductive layer, the area around the connecting pipe 102, including the corner between the side surface 101b and the connecting pipe 102, can be made the entire area subject to spark testing over a wide range. That is, when constructing the waterproof structure 1, the waterproofing performance of the waterproof sheet around the connecting pipe 102 can be confirmed by spark testing.

[0066] Furthermore, by using conductive layer-equipped waterproof sheets 2 and 3 in which the conductive layers 20 and 30 are laminated and integrated with the waterproof sheets 21 and 31, handling at the construction site is improved compared to when the conductive layer and waterproof sheet are not laminated and integrated, and the construction of the waterproof structure 1 can be made easier.

[0067] Furthermore, the second portion 3b of the waterproof sheet 3 with the second conductive layer is a structurally weak part, and there is a risk that in the future, due to impact or deterioration over time, the second portion 3b may peel off or be damaged, reducing the waterproofness. However, in this embodiment, the second portion of the waterproof sheet 3 with the second conductive layer is covered by a waterproof cover sheet 4. This reduces the possibility that the waterproofness of the waterproof structure 1 may decrease in the future.

[0068] Furthermore, as mentioned above, the appearance of the waterproof structure 1 is poor if the second part 3b is located on the surface of the waterproof structure 1, due to reasons such as the presence of multiple cuts 3b1 in the second part 3b. Therefore, the appearance of the waterproof structure 1 can be improved by covering the second part 3b with a waterproof cover sheet 4, as in this embodiment.

[0069] Furthermore, the water-impermeable cover sheet 4 covers not only the second portion 3b but also the portion of the water-impermeable sheet 2 with the first conductive layer other than the outer edge portion 2b. This further reduces the possibility of a decrease in the water-impermeableness of the water-impermeable structure 1 in the future.

[0070] Furthermore, the shape and size of the through-hole 2a in the waterproof sheet 2 with the first conductive layer satisfy at least one of the following conditions: the gap between the edge of the through-hole 2a and the outer contour of the connecting pipe 102 is 20 mm or less; the gap between the edge of the through-hole 2a and the outer contour of the connecting pipe 102 is 10% or less of the diameter of the through-hole 2a; or 50% or more of the entire circumference of the through-hole 2a is in contact with the outer surface of the connecting pipe 102. This reduces the possibility of gaps that could cause water leakage occurring at the boundary between the edge of the through-hole 2a in the waterproof sheet 2 with the first conductive layer and the outer surface of the connecting pipe 102. As a result, the waterproofness of the waterproof structure 1 can be improved.

[0071] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible as long as they are within the scope of the claims. Modifications will be described below.

[0072] (modified version) As shown in the modified example in Figure 7, the water-blocking structure 301 may consist of a water-blocking sheet 2 with a first conductive layer, a water-blocking sheet 3 with a second conductive layer, and a water-blocking cover sheet 4 as one set, and two sets of these sets 302 and 304 may be laminated around the water-blocking structure to be blocked by the connecting pipe 102.

[0073] Specifically, the waterproofing structure 301 is laminated around the waterproofing structure surrounding the connecting pipe 102 in the following order: lower protective mat 201, lower set body 302, middle protective mat 303, upper set body 304, and upper protective mat 203. The middle protective mat 303 is made of synthetic resin, similar to the lower protective mat 201 and upper protective mat 203. Set bodies 302 and 304 include a waterproofing sheet 2 with a first conductive layer, a waterproofing sheet 3 with a second conductive layer, and a waterproofing cover sheet 4.

[0074] In the waterproofing process for laying the waterproofing structure 301, after the above-described first placement process, second placement process, inspection process, and third placement process for laying the lower layer set body 302 are carried out, the first placement process, second placement process, inspection process, and third placement process for laying the upper layer set body 304 are carried out.

[0075] According to the water-blocking structure 301 of the modified version described above, since two sets of sets 302 and 304 are laminated, the water-blocking properties of the water-blocking structure 301 can be further improved. As a modification, a water-blocking sheet 2 with a first conductive layer, a water-blocking sheet 3 with a second conductive layer, and a water-blocking cover sheet 4 may be formed as one set, and three or more sets may be laminated on the structure to be blocked from water.

[0076] Other variations are described below.

[0077] In the above-described embodiment, a plurality of notches 3b1 were made in the second portion 3b of the waterproof sheet 3 with the second conductive layer, but notches are not required. For example, the second portion 3b of the waterproof sheet 3 with the second conductive layer may be formed in an annular shape, and its inner periphery may be connected to the first portion 3a.

[0078] In the above-described embodiment, the water-blocking structure 1 included a lower protective mat 201, a water-blocking cover sheet 4, and an upper protective mat 203, but these are not essential. Furthermore, the water-blocking cover sheet 4 may be arranged to cover only the second portion 3b of the water-blocking sheet 3 with the second conductive layer, or it may be arranged to cover both the second portion 3b and the entire water-blocking sheet 2 with the first conductive layer.

[0079] The waterproofing method for the waterproofing structure 1 described above is just one example, and any waterproofing method that forms the waterproofing structure 1 may be modified. For example, the joining of the outer edge 2b of the waterproofing sheet 2 with the first conductive layer and the edge of the hole 202a of the waterproofing sheet 202 may be performed after the spark test to confirm the waterproofing of the waterproofing sheet 2 with the first conductive layer has been completed. In this case, since there is no need to leave an unjoined portion on the outer edge 2b of the waterproofing sheet 2 with the first conductive layer, the entire outer edge 2b of the waterproofing sheet 2 with the first conductive layer is joined to the edge of the hole 202a of the waterproofing sheet 202 at once. Also, the joining of the U-shaped outer edge of the second part 3b and the waterproofing sheet 2 with the first conductive layer may be performed after the spark test to confirm the waterproofing of the waterproofing sheet 3 with the second conductive layer has been completed. In this case, since there is no need to leave an unjoined portion on the U-shaped outer edge of the second portion 3b, the entire U-shaped outer edge of the second portion 3b is joined to the first conductive layer-equipped water-blocking sheet 2 at once.

[0080] Furthermore, the spark test to confirm the water-impermeableness of the first conductive layer-equipped water-impermeable sheet 2 may be performed after the first placement step in which the first conductive layer-equipped water-impermeable sheet 2 is placed, and before the second placement step in which the second conductive layer-equipped water-impermeable sheet 3 is placed. In this case, the spark test for the first conductive layer-equipped water-impermeable sheet 2 is completed, followed by the second placement step in which the second conductive layer-equipped water-impermeable sheet 3 is placed, and then the spark test to confirm the water-impermeableness of the second conductive layer-equipped water-impermeable sheet 3 is performed.

[0081] The above-described embodiment is an example of applying the present invention to a waterproof structure for a waste disposal site, but the application of the present invention is not limited to waste disposal sites. The present invention can be applied to waterproof structures other than waste disposal sites, such as retention ponds for adjusting water volume during river floods, and reservoirs for storing river water or rainwater, as long as it is laid on a waterproof structure having a laying surface and protrusions protruding from the laying surface. The protrusions are not limited to connecting pipes. The shape of the protrusions is not limited to the shape of a circular pipe. The laying surface is not limited to a slope. [Explanation of Symbols]

[0082] 1. Waterproof structure 2. Waterproof sheet with first conductive layer 2a Through hole 3. Waterproof sheet with second conductive layer 3a 1st part 3b 2nd part 4. Water-resistant cover sheet 20 First conductive layer 21. First waterproof sheet 30 Second conductive layer 31. Second waterproof sheet 102 Communication pipe 301 Waterproof structure

Claims

1. A waterproofing structure to be laid on a waterproofing target structure having a laying surface and a protrusion projecting from said laying surface, The invention comprises a waterproof sheet with a first conductive layer, wherein the first conductive layer is laminated and integrated with the first waterproof sheet, and a waterproof sheet with a second conductive layer, wherein the second conductive layer is laminated and integrated with the second waterproof sheet. The waterproof sheet with the first conductive layer has through holes for inserting the protrusions, and is positioned relative to the laying surface such that the first conductive layer faces the laying surface. The waterproof sheet with the second conductive layer includes a first portion and a second portion connected to the first portion. The first portion is arranged to cover the entire outer surface of the protrusion such that the second conductive layer faces the protrusion. The water-blocking structure is characterized in that the second portion is bent relative to the first portion so as to conform to the laying surface, and is arranged on a water-blocking sheet with a first conductive layer such that the second conductive layer faces the laying surface.

2. The water-blocking structure according to claim 1, further comprising a water-blocking cover sheet having a through hole for inserting the protrusion and disposed to cover at least the second portion of the water-blocking sheet with the second conductive layer.

3. The water-blocking structure according to claim 2, characterized in that the water-blocking cover sheet is arranged to cover at least a portion of the first conductive layer water-blocking sheet in addition to the second portion of the second conductive layer water-blocking sheet.

4. The water-blocking structure according to claim 2 or 3, characterized in that the first conductive layer-equipped water-blocking sheet, the second conductive layer-equipped water-blocking sheet, and the water-blocking cover sheet are treated as one set and multiple sets are laminated on the water-blocking target structure.

5. The water-blocking structure according to claim 1, characterized in that the shape and size of the through-hole in the water-blocking sheet with the first conductive layer is such that the gap between the edge of the through-hole and the outer contour of the protrusion is 20 mm or less, the gap between the edge of the through-hole and the outer contour of the protrusion is 10% or less of the diameter of the through-hole, or the shape and size such that 50% or more of the entire circumference of the through-hole is in contact with the outer surface of the protrusion.

6. A waterproofing method for laying a waterproofing structure on a waterproofing target structure having a laying surface and protrusions projecting from said laying surface, A first arrangement step for arranging a waterproof sheet with a first conductive layer, wherein the first conductive layer is laminated and integrated with the first waterproof sheet, the first arrangement step of inserting the protrusion through a through hole formed in the waterproof sheet with the first conductive layer, and arranging the waterproof sheet with the first conductive layer with the laying surface with the first conductive layer facing the laying surface, A waterproofing method characterized by comprising a second placement step for arranging a waterproofing sheet with a second conductive layer, in which a second conductive layer is laminated and integrated with a second waterproofing sheet, wherein a first portion of the waterproofing sheet with the second conductive layer is positioned so as to cover the entire outer surface of the protrusion with the second conductive layer facing the protrusion, and a second portion connected to the first portion of the waterproofing sheet with the second conductive layer is bent relative to the first portion so as to follow the laying surface, and the waterproofing method characterized by comprising a second placement step for arranging a waterproofing sheet with a second conductive layer with the second conductive layer facing the laying surface.

7. An inspection step in which the water-blocking performance of the first conductive layer-equipped water-blocking sheet arranged in the first arrangement step and the second conductive layer-equipped water-blocking sheet arranged in the second arrangement step is inspected by spark testing, The waterproofing method according to claim 6, further comprising a third placement step of arranging a waterproof cover sheet after the inspection step, wherein the protrusion is inserted through a through hole formed in the waterproof cover sheet and the waterproof cover sheet is arranged such that it covers at least the second portion of the waterproof sheet with the second conductive layer.

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