JP3648680B2 - Fixing structure at the edge of the water shielding sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing structure of an end portion of a water shielding sheet, and when the end portion of a water shielding sheet laid in a storage area such as a disposal site is fixed to a structure built in the area, The present invention also relates to a fixing structure for an end portion of a water shielding sheet that allows the end portion of the water shielding sheet to be firmly fixed to the structure even when ground subsidence occurs around the structure.
[0002]
[Prior art]
In storage facilities such as landfill disposal sites for general waste, impermeable works are implemented throughout the storage area to prevent the leachate leached from the stored waste from leaking to the ground outside the disposal site. As the water-impervious work, generally, a method of laying various polymer-based water-impervious sheets on the entire ground surface of the storage area, or the like is employed. Also, a storage facility that has a leachate collection and drainage pipe network in order to discharge the leachate generated in the storage area to the outside, and can drain it to the outside through the water absorption holes constructed in the storage area. There is also.
[0003]
When there is such a structure in the storage area, it is necessary to prevent leakage of leachate from the boundary between the water-impervious sheet and the structure when the water-proof sheet is spread on the ground in the storage area. . For this reason, the edge of the sheet must be directly fixed to the concrete structure around the structure to ensure water tightness.
[0004]
FIG. 4 is a schematic diagram schematically showing the above situation. The concrete structure 51 partially shown in the figure is constructed at a predetermined position in the storage area 50, and the lower part of the skeleton is backfilled with backfill soil 52. Further, a water shielding sheet 54 is laid on the shaped specified ground surface 53 so as to cover the entire storage area. The water shielding sheet 54 is raised by a predetermined height along the structure 51 with the sheet end 54 a bent upward at the position of the structure 51. A pressing plate 55 is disposed on the upper end portion 54b of the sheet. The pressing plate 55 is fixed to the concrete surface of the structure 51 via a fixing member 56 such as a post-fixed anchor with the upper end portion 54b of the sheet interposed therebetween. Yes. For simplification of the drawing, the sealing material filled along the boundary between the sheet edge and the structure surface and the cover covering the pressing plate 55 are not shown.
[0005]
[Problems to be solved by the invention]
Incidentally, as described above, the concrete structure 51 shown in FIG. 4 is often backfilled with backfill soil 52. Therefore, ground subsidence may occur around the structure 51 as it is used as a disposal site and waste is being reclaimed. In this case, since the structure 51 is supported by the supporting ground, it does not sink, but it is expected that only the portion of the water shielding sheet laid on the ground surface is pulled downward following the settlement of the surrounding ground. Since this waterproof sheet uses a relatively flexible sheet such as a high-density polyethylene sheet, it stretches to a certain degree of settlement, but if the elongation exceeds the allowable amount and exceeds the tensile strength of the sheet, As shown in FIG. 5, the sheet end 54 a near the hole of the water shielding sheet may break at the anchor fixing portion, and the sheet end may be detached from the concrete structure 51. For this reason, there is a possibility that waste leachate may leak from the boundary portion between the concrete structure 51 and the water shielding sheet 54.
[0006]
Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, and even when the ground subsidence occurs around the structure built in the disposal site, the water shielding sheet fixed to the structure is provided. An object of the present invention is to provide a fixing structure for an end portion of a water shielding sheet that is securely held and does not have a risk of water leakage from a boundary portion between the structure and the water shielding sheet.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention is such that the end of a double-layer water-proof sheet laid on the ground in a predetermined area and having a drainage layer formed therein is erected from the ground in the area. When fixing to the outer peripheral part of the structure, a bracket for mounting the end of the water shielding sheet is provided at a height for fixing the water shielding sheet of the structure so as to surround the outer peripheral part of the structure. The upper surface base portion side of the bracket and the lower end side of the rising portion of the structure are covered with a resin lining sheet, and the sheet end portion on the lower surface side of the water shielding sheet is formed on the resin lining sheet covering the bracket. While fixing, the sheet | seat edge part of the upper surface side of the said water shielding sheet was fixed to the resin lining sheet which covered the standing part of the said structure .
[0008]
The resin lining sheet is preferably fixed to the surface of the structure and the bracket with protrusions or studs formed on the back surface .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a fixing structure for an end portion of a water shielding sheet according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view schematically showing the entire cross section of a general waste landfill site. The figure shows a part of a water absorption person hole 5 connected to a leachate collection / drainage pipe (not shown) piped in the storage area 1 of the disposal site. The water-absorbing human hole 5 as a structure constructed in the storage area 1 is filled with a filter material, and leachate flowing in by a pumping facility (not shown) can be discharged out of the disposal site. This water absorption hole 5 is erected on the ground 3 deeper than the planned bottom surface 2 in the storage area 1, and the lower part 5 a of the skeleton is backfilled to the ground surface of the planned bottom surface 2 by the backfill soil 4. On this ground surface, a high-density polyethylene water shielding sheet is laid over the entire surface. In the impervious construction using this water-impervious sheet 10, roll-shaped sheets having a predetermined width are laid out while taking a predetermined overlap allowance, and the overlapping portions of adjacent sheets are heat-sealed and integrated into a storage region 1. The entire ground surface is covered. A known hot welder or the like is used for heat fusion between the water shielding sheets 10.
[0012]
Immediately below the ground surface of the water-absorbing hole 5 where the lower part 5a is backfilled, a concrete frame 5A (here, the water-absorbing hole 5 is considered as an example of a concrete structure constructed in such a situation. The sheet receiving bracket 20 is provided so as to surround the entire periphery of the housing 5A. The configuration of the sheet receiving bracket 20 and the configuration of the end portion of the water shielding sheet fixed to the upper surface of the sheet receiving bracket 20 will be described with reference to FIGS.
In FIG. 2, a part of the concrete frame 5A with the lower part 5a buried therein, a part of the sheet receiving bracket 20 provided on the outer periphery of the concrete frame 5 directly below the ground surface, and an upper surface 20a of the sheet receiving bracket 20 are shown. A portion backfilled by the backfill soil 4 and a part of the water shielding sheet 10 laid on the ground surface of the planned bottom surface 2 of the storage area 1 are shown. The water-impervious sheet end portion 10a is placed on the sheet receiving bracket 20 and further fixed to the surface of the concrete casing 5A.
[0013]
The sheet receiving bracket 20 is a concrete member having a cantilever structure that is placed separately from the concrete housing 5A. In the present embodiment, the upper surface 20a is finished almost horizontally, and a haunch is formed in the lower part. The seat receiving bracket 20 is provided so that the position of the upper surface 20a thereof is at substantially the same level as the backfill portion around the concrete frame 5A and the ground surface of the planned bottom surface 2. In the present embodiment, the width is set to 400 mm and the end height is set to 300 mm. This sheet receiving bracket 20 is placed in a portion partitioned by a side mold (not shown) assembled on the backfill soil 4 backfilled up to a predetermined height around the concrete housing 5A. It is unreinforced concrete using the same strength concrete as the concrete. The joint surface 21 with the concrete housing 5A is integrated in a state where a part of the surface of the concrete housing 5A side surface is removed and roughened for attaching a lining sheet to be described later.
[0014]
In order to integrate the sheet receiving bracket 20 with the concrete housing 5A, an integrated structure may be used when the bracket 20 and the concrete housing 5A are constructed. Further, as a method of post-installing the bracket 20, an anchor member such as a reinforcing bar is provided on the concrete frame 5A side, and the concrete is placed by joining with the joining bars arranged from the bracket 20 side. Good. If the cross-sectional shape can also ensure the strength at the joint surface, it is possible to eliminate the haunch and to set various types of beams. Furthermore, since the bracket 20 itself does not require high strength, it may be poor blended concrete. Light weight concrete may be used to reduce the weight of the member. If durability is maintained as the bracket 20 in the ground, a bracket made of steel is attached to a predetermined position of the concrete frame 5A with a fixing member such as an anchor, and a precast concrete plate or the like is laid on the bracket to form an upper surface plate. You can also.
[0015]
Next, the structure of the fixing structure of the water shielding sheet end 10a will be described with reference to FIG. A high-density polyethylene studded lining sheet 22 is laid on the upper surface 20a of the sheet receiving bracket 20 so as to be integrated with the concrete surface. The lining sheet 22 with studs has a number of key-shaped protrusions 22a formed on the back surface, and the lining sheet 22 is integrated with the concrete surface by laying the key-shaped protrusions 22a on the concrete surface immediately after placing. Can be attached. The lining sheet 22 is also attached to the concrete housing 5A side, and the upper end 22b of the lining sheet 22 is fixed to the concrete housing 5A via a pressing plate 24 fixed by a post-casting anchor 23. Further, in the present embodiment, a water stop rod 28 is attached to the concrete side of the lining sheet 22, and water stop between the back surface of the lining sheet 22 and the concrete is also achieved. A known hole-in anchor is used as the post-casting anchor 23. The holding plate 24 is made of a flat bar made of an aluminum plate, and a plate having a predetermined length is attached along the longitudinal direction of the sheet. The anchor 23 and the entire pressing plate 24 are entirely covered with a sheet 25 made of the same material as that of the water shielding sheet 10 in order to prevent water leakage. A silicone resin caulking 26 is applied to the upper end of the sheet.
[0016]
On the other hand, a part of the lower water-impervious sheet 10 </ b> A on which the ground surface has been laid is placed on the upper surface 20 a of the sheet receiving bracket 20, and the end 10 a is heat-sealed on the lining sheet 22. A horizontal drain material 27 is laid on the lower water-impervious sheet 10A. The horizontal drain material 27 is a three-dimensional fiber network that holds a space 27a having a predetermined thickness whose upper and lower surfaces are covered with a nonwoven fabric. The space portion 27a has a rigidity that does not collapse against a predetermined surface pressure. Yes. When laid in the soil or the like, leachate can be drained along a water gradient through the space portion 27a. An upper water-impervious sheet 10 </ b> B is laid on the upper surface 20 a of the horizontal drain material 27. The end portion of the upper water-impervious sheet 10B is folded and overlapped by a predetermined height on the lining sheet 22 raised to the concrete casing 5A side, and the end portion 10a is heat-sealed on the lining sheet 22.
[0017]
Since the fixing portion of the end portion 10a of the water-impervious sheets 10A and 10B is configured as described above, the backfill soil 4 sinks around the concrete casing 5A as shown in FIG. 3, and the end portion 20b of the sheet receiving bracket 20 Even if the outer water-impervious sheet 10 is partially deformed following the settlement, the deformation is within an allowable range due to the flexibility of the sheet. At that time, the fixing portion of the water-impervious sheet end portion 10a is on the sheet receiving bracket 20, so that it is not affected by the settlement at all, and the water-blocking performance at the fixing portion is not affected at all.
[0018]
【The invention's effect】
As described above, when laying a water shielding sheet at a landfill site, it is ensured that water leakage will occur due to breakage of the anchoring part of the edge of the water shielding sheet due to the uneven settlement that occurs with the concrete structure, etc. It has the effect that it can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a fixing structure of an end portion of a water shielding sheet of the present invention.
2 is a partial perspective view showing an enlarged cross section of the fixing structure at the end portion of the water shielding sheet in FIG. 1;
3 is a cross-sectional view further enlarging a cross section of the fixing structure of the sheet end portion shown in FIG. 2;
FIG. 4 is a partial perspective view illustrating an example of a fixing portion at an end portion of a conventional water shielding sheet.
5 is a partial perspective view schematically illustrating a state in which a fixing portion at an end portion of the water shielding sheet illustrated in FIG. 4 is broken.
[Explanation of symbols]
1 Storage Area 2 Planned Bottom 4 Backfill Soil 5 Water Absorber Hole (Structure)
5A Concrete frame 10 Water-impervious sheet 20 Sheet receiving bracket 22 Lining sheet 23 Anchor 24 Holding plate 27 Horizontal drain material

Claims (2)

When fixing the end portion of the double-layer water-proof sheet laid on the ground in the predetermined area and having a drainage layer formed on the outer peripheral portion of the structure standing from the ground in the area A bracket for mounting an end of the water shielding sheet is provided at a height for fixing the water shielding sheet of the structure so as to surround an outer peripheral portion of the structure; The lower end side of the rising part of the object is covered with a resin lining sheet, the sheet end on the lower surface side of the water shielding sheet is fixed on the resin lining sheet covering the bracket, and the rising part of the structure A fixing structure for an end portion of a water shielding sheet, wherein the sheet end portion on the upper surface side of the water shielding sheet is fixed to a resin lining sheet covering the surface . 2. The fixing structure for an end portion of a water shielding sheet according to claim 1, wherein the resin lining sheet is fixed to a surface of the structure and the bracket by a protrusion or a stud formed on a back surface .

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