JP3945907B2 - Water shielding facilities using drainage layers at waste disposal sites - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a water shielding facility for blocking infiltration of leachate such as rainwater and water leakage in a pit in a final waste disposal site (general waste disposal site, industrial waste disposal site, etc.). About.
[0002]
[Prior art]
In recent years, environmental pollution due to leachate such as rain water, water leakage, and spring water that passes through the pits of waste final disposal sites such as general waste treatment plants and industrial waste treatment plants has become a social problem. In view of this, the leachate generated from the final disposal site of the waste will not be leaked underground (outside the pit), but will be appropriately, safely and promptly processed to prevent environmental pollution to the surroundings. Efforts are being made to focus on new technologies.
[0003]
By the way, the conventional water-blocking system has a water-blocking sheet that is laid on the slope and bottom of the pit even if rainwater that falls on the pit of the final disposal site penetrates and passes through the waste and becomes leachable water. The structure has a water shielding sheet structure configured to block penetration into the ground. Further, the leachate flows down along the slope of the slope / bottom surface by the water shielding sheet structure, is led to the treatment device by the water collecting device, is discharged after being treated.
[0004]
However, if there is a heavy machine or a fallen object during construction of the final disposal site, or if the impervious sheet structure is damaged due to an impact at the time of waste disposal, leachate will be discharged from the damaged part. It is thought that it leaks into the inside.
[0005]
Therefore, for example, as disclosed in JP-A-6-171005, a water-swellable substance is disposed in a planar space formed by an upper layer impermeable sheet and a lower layer impermeable sheet, or JP-A-6-218345. As shown in the publication, the lower water-swellable fiber layer and the upper water-swellable fiber layer laminated between the upper water-impervious sheet and the lower water-impervious sheet are laminated between the water-swellable fiber layers. Some have a core layer.
[0006]
In any case, when the water shielding sheet structure is damaged, the water swellable substance of the water swellable fiber layer absorbs the leachate and swells to swell the water.
[0007]
[Problems to be solved by the invention]
However, recent waste disposal sites, especially leachate from waste incineration ash, contain a large amount of various chlorides, and the cl ion concentration is about 20,000 mg / l, and 13,000 mg / l at 30 mm / h rainfall. There is also a report.
[0008]
Under this circumstance, most of the water-impervious sheets using the water-swellable substances currently on the market are affected by the cl ions contained in the leachate, so that the water-swellable substances are less likely to swell and impermeable to water. It will be enough.
[0009]
Then, this invention aims at provision of the water-impervious facility of the waste final disposal site which can solve the said subject.
[0010]
[Means for Solving the Problems]
The problem-solving means in the present invention protects the water shielding structure provided so as to cover the pit from the upper layer in order to prevent the leachate from penetrating into the ground and to guide the leachate to a predetermined location. Layer, upper impermeable layer, self-healing layer, drainage layer, and lower impermeable layer, and the sheet-like fiber drainage material constituting the drainage layer is composed of filaments with a single yarn diameter of 0.14 mm or more. The fiber filling amount is set to 40% or less, and the thickness is set to 2 to 20 mm.
[0011]
The above-mentioned protective layer prevents damage to the lower layer, and the entire waterproof sheet structure is extremely robust and difficult to break due to the five-layer structure of the protective layer, upper impermeable layer, self-healing layer, drainage layer and lower impermeable layer. Therefore, the danger that leachate penetrates into the ground is suppressed.
[0012]
Further, as the drainage layers, with a hydraulic gradient 0.03 (3%) · 5kg / cm 2 permeability during loading is 0.1 cm / sec or more sheet-like fibrous drainage material, or as a sheet-like fibrous drainage material The use of a warp knitted fabric having a hydraulic permeability gradient of 0.03 (3%) and 5 kg / cm ^{2 and having} a water permeability coefficient of 0.1 cm / sec or more enables quick and reliable introduction of leachate.
[0013]
Furthermore, by providing the suction means for sucking the leachate leaked into the drainage layer and promoting the drainage, the leachate is introduced more quickly. Moreover, even if the upper and lower impermeable layers are broken, the water permeability coefficient is high as described above, so that the water can be drained faster than it diffuses into the soil.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, a water-impervious facility 1 according to an embodiment of the present invention includes a pit 2 and a water-impervious sheet structure 3 that covers the pit 2, and various impacts are applied to the water-impervious sheet structure 3. However, even if damage (occurrence of a hole or the like) occurs in the water shielding sheet structure 3, it is safe to prevent or suppress the infiltration of the leachate 10 into the ground 4. And high reliability.
[0015]
And the said water-impervious sheet structure 3 consists of the protective layer 5-upper impermeable layer 6-self-healing layer 7-drainage layer 8-lower lower impermeable layer 9 arrange | positioned in an order from the upper layer laid in the pit 2. Yes.
[0016]
The protective layer 5 which is the uppermost layer is easy to perform on-site and has a function of absorbing this against an impact. For example, the protective layer 5 is made of a fiber material which is not easily torn such as polyester and polypropylene, and has a thickness of 2 mm or more. Sheet. A thickness of 4 mm to 50 mm is desirable in terms of impact absorption and tear resistance.
[0017]
Next, the upper water-impervious layer 6 is a composite resin sheet reinforced with a synthetic fiber woven fabric as a core material. For example, a woven fabric made of synthetic fibers such as nylon, polyester, and aramid is used as a reinforcing core material. For example, a composite resin sheet in which a resin film such as HDPE or LDPE which is polyethylene is formed on at least one side of the cloth is used. This means that by forming a resin film using a woven fabric as a reinforcing core material and making a composite sheet with the resin, the strength of the sheet made only of the resin is increased several times to several tens of times, and the impact resistance, This has the effect of preventing tearing and preventing dimensional changes due to thermal expansion of the resin sheet, thereby improving the safety and reliability of the entire water shielding sheet structure 3.
[0018]
The self-healing layer 7 has a water-swellable polymeric resin agent of 200 to 1,000 g / m ² placed on a sheet such as a spunbond sheet such as polyester or polypropylene having a thickness of ² mm to 10 mm. The sheet is used and is laid under the upper water-impervious layer 6. As the water-swellable polymer resin agent, one that is not affected by or is not easily affected by the cl ions contained in the leachate 10 that has leaked through the upper water shielding layer 6 and leaked.
[0019]
For example, starch polymer, polyacrylic hydrochloric acid polymer, polyacrylic hydrochloric acid-polyacrylamide copolymer, polyacrylamide polymer, vinyl hydrochloride-acrylic acid ester copolymer, vinyl acetate-maleic acid ester copolymer Polymers, isobutylene-maleic anhydride copolymers, polyacrylonitrile polymers, polyethylene oxide polymers, poly-N-vinylacetamide (PVNA), and the like are used. Particularly preferred are polyacrylate-polyacrylamide copolymers, polyacrylamide polymers, and polyethylene oxide polymers that can absorb aqueous solutions of salts and the like.
[0020]
The self-healing layer 7 blocks and repairs the leachate 10 in order to prevent the leachate 10 from penetrating into the ground 4 when leaked water passes through the upper impermeable layer 6 and the leachate 10 is generated. In order to prevent water leakage, the scale of damage is large and the water leakage continues beyond the limit of the self-repair capability, or the leachate 10 is quickly drained at the initial stage until the repair is completed. If necessary, the drainage layer 8 is useful, and the drainage layer 8 has a hydraulic permeability of 0.03 (3%) · 5 kg / cm ^{2 and} has a hydraulic conductivity of 0.1 to 5.0 cm when loaded. A sheet-like fiber drainage material having a three-dimensional thickness made of synthetic fiber of / sec is used as the drainage material. That is, for example, in the case of a woven fabric, this sheet-like fiber drainage material is a sheet having a three-dimensional thickness by three-dimensionally connecting the front and back ground structures woven by a moquette loom. If it is a knitted fabric, it is knitted by a radial knitting machine and a circular knitting machine having a two-row needle bed. In the case of a net-like sheet, for example, a thermoplastic polymer composition is melt-spun from a nozzle into a fiber thread, and a ramen structure is formed on a take-up belt that swings at an interval until the yarn immediately after spinning is not cured. Are laminated and fused to create a desired thickness.
[0021]
Synthetic fibers such as polyamide, polyester, polypropylene, vinylon, and aramid are preferably used as the fiber material used for the knitted fabric and net-like body that are sheet-like fiber drainage materials, and monofilaments, monomultifilaments, multifilaments, and flat cross sections are used. , Irregular cross-sections, etc., dyed yarn and processed yarn of these fibers, or original fibers colored at the time of fiber production, and these materials may be used alone or in combination, application, purpose, required performance A fiber material suitable for the above is selected and used as appropriate.
[0022]
Furthermore, in the embodiment of the present invention, the sheet-like fiber drainage material is a sheet having a three-dimensional thickness by three-dimensionally connecting the front and back ground structures knitted by a warp machine having a two-row needle bed with a connecting thread. Is preferable. The fiber material in this case is not particularly limited, and the fiber material is appropriately selected and used. However, in order to obtain necessary drainage performance, consideration is given to the following.
[0023]
That is, the sheet-like fiber drainage material contains 30% by weight or more of filaments having a single yarn diameter of 0.14 mm to 0.7 mm , and the fiber filling amount per unit volume at the time of no loading is set to 5% to 40%. It is that you are. If single yarn diameter of the filaments is less than 0.14 mm, compression resistance of the sheet-like fibrous drainage material, or insufficient cushioning property, voids required for high mounting load may be inadequate can hardly drainage performance is secured. In addition, when the ratio of filaments having a single yarn diameter of 0.14 mm or more is less than 30% by weight of the fiber material constituting the sheet-like fiber drainage material, the sheet-like fiber drainage material has insufficient compression resistance or a high load Sometimes it is difficult to secure the necessary gaps, and the drainage performance may be insufficient . In addition, when the fiber filling amount per unit volume when there is no load exceeds 40%, the fiber density of the sheet-like fiber drainage material becomes too high, resulting in less voids in the sheet, and the expected drainage and water guiding effect is obtained. It may be difficult to be confused. The fiber filling amount is a value indicating the ratio of the fiber volume in the volume per unit volume of the fiber drainage material A.
[0024]
Furthermore, although it is a requirement that the thickness of the sheet-like fiber drainage material is 2 to 20 mm, if the thickness is less than 2 mm, the amount of voids necessary for drainage cannot be secured in the sheet-like fiber drainage material. In some cases, the drainage function cannot be demonstrated. Further, if it exceeds 20 mm, there is no particular problem with respect to drainage, but the thickness of the sheet-like fiber drainage material becomes too thick, and workability at the time of laying may deteriorate. In particular, when a person rides on the fiber drainage material A when laying on a slope, the foot becomes unstable.
[0025]
Next, the sheet-like fiber drainage material according to the embodiment of the present invention has an in-plane water permeability coefficient of 0.1 cm / sec or more when loaded with a dynamic gradient of 0.03 (3%) · 5 kg / cm ^2. Is desirable. In the embodiment of the present invention, the in-plane permeability coefficient necessary for quickly draining and guiding the leachate 10 caused by water leakage generated in the waste treatment plant is several times the in-plane permeability coefficient of sand or nonwoven fabric. Ten times the performance is required. If it is less than 0.1 cm / sec, the drainage performance is inferior, and the desired drainage function may not be obtained. In addition, the in-plane permeability coefficient at the time of no load is set to 5 to 110 cm / sec.
[0026]
Furthermore, the strength of the sheet-like fiber drainage material in the embodiment of the present invention is preferably 100 kg / m or more in the vertical direction and 50 kg / m or more in the horizontal direction. This is a strong value necessary to withstand the tensile force applied when laying the sheet-like fiber drainage material at the time of construction of the waste treatment plant, and if the value is below each value, the sheet may be damaged during construction or the durability may be increased. A problem may arise or the quality of the entire water-impervious sheet structure 3 may be inferior.
[0027]
Next, the lower water shielding layer 9 used for the lowermost layer uses a composite resin sheet reinforced with a fiber material as a core material. As the role of the lower impermeable layer 9 used as the lowermost layer, when the four layers installed on the lower impermeable layer 9 do not perform their original functions due to some damage, the leachate 10 due to leakage leaks into the ground. In addition to blocking the water so that it does not occur, the leachate 10 has a function of quickly discharging the water. Furthermore, it has a function to prevent spring water generated from the ground side from entering the upper layer. Furthermore, when there is a protrusion on the ground or when there is some strong impact from the upper layer portion, the entire multilayer structure is protected from being damaged.
[0028]
Therefore, the lower water-impervious layer 9 is a composite resin sheet reinforced with a fiber material as a core material, and more specifically, a composite resin sheet in which one side of the fiber material is coated with a resin. As the fiber material according to the embodiment, for example, synthetic fibers such as polyamide, polyester, polypropylene, vinylon, and aramid are preferably used. Monofilament, monomultifilament, multifilament, cross section is flat, irregular cross section, etc. Natural dyed fibers such as pre-dyed yarns and processed yarns of these fibers, or original fibers colored during fiber production may also be used. Furthermore, these materials may be used alone or in combination, and a fiber material suitable for the purpose, purpose, required performance, etc. is appropriately selected and used.
[0029]
Further, the shape of the fiber material is not particularly limited, but a sheet-like (fabric) woven fabric, a knitted fabric, and a non-woven fabric are preferable. In order to give impact absorption and strength performance, a thick woven fabric having a thickness of 1 mm or more and a double tissue weaving or more is more preferable. By making a composite resin sheet in which at least one side of this fiber material is coated with a resin such as polyethylene, which is HDPE, LDPE, the strength of the sheet made of resin alone is increased to several to several tens of times in a remarkable case, and impact resistance Effects, such as prevention of dimensional changes due to thermal expansion of the resin sheet, thereby improving the safety and reliability of the entire water shielding sheet structure 3.
[0030]
The material detailed above is laid on the slope and bottom surface in the waste treatment site pit 2 in the above order to construct the water shielding equipment 1 according to the embodiment of the present invention. Various variations are conceivable for this aspect. For example, there is an aspect in which both the water shielding layers except for the opening portions necessary for drainage of the water shielding sheet structure 3 laid in the specified order are bonded by welding, etc., and divided lanes are provided for construction. is there. In addition, the in-plane permeability coefficient and dynamic water gradient in this application were calculated | required by the following Formula according to the JSF932-199X method of the Geotechnical Society of Japan.
In-plane permeability coefficient = Outflow water amount x Sample length / water head x Permeable area (sample width x thickness) x Outflow water amount Time dynamic gradient = Water head x Sample length Next, the impermeable sheet structure 3 will be described more specifically. To do. That is, the water shielding sheet structure 3 composed of five layers (protective layer 5 -upper water shielding layer 6 -self-healing layer 7 -drainage layer 8 -lower water shielding layer 9) was made of the following materials.
[0031]
Protective layer 5: A non-woven fabric (in the example, trade name: polyester spunbonded non-woven fabric sheet AN400 manufactured by Unitika Co., Ltd.) excellent in cushioning and impact resistance, having a thickness of 5 mm and a basis weight of 400 g / m ² was used. .
[0032]
Upper impermeable layer 6: plain weave structure, nylon 840d / 140f high strength yarn for warp and weft (strength 10.3kg / d, intermediate elongation 14.5% at 4.5kg load, cutting elongation 21.0%) Excellent physical properties with a total thickness of 1.5 mm coated with polyethylene resin (LDPE) by calender coating on both sides of a woven fabric of density vertical x weft = 20/２０ x 20 / 吋 using calender (JIS A 6022) Tensile strength = 73.1 kgf / cm, weft 69.2 kgf / cm, elongation at break = 1099%, 1021% weft, JIS L1096 trabezoid method tear strength = 117.0 kgf, weft 125.8 kgf, murren burst test = 60 kgf / cm ² or more) was prepared and used.
[0033]
Self-healing layer 7: PE film (0.1 mm) from the upper layer-Polyester spunbond (AN-200 manufactured by Unitika Co., Ltd.)-High water-absorbing acrylic resin (AP20-; manufactured by Sanyo Chemical Co., Ltd.) 100 / m ² -Polyester A sheet in which spunbond (AN-200 manufactured by Unitika Ltd.)-PE film (0.1 mm) was integrally bonded and laminated was used.
[0034]
Drainage layer 8: A warp knitting machine having a 14-gauge double-row needle bed in which a rigid monofilament is improved in knitting nitti lent, and has a warp of 0.165 mm on the front and back fabric L1, L6. A nylon monofilament and a nylon multifilament of 300d / 7f are connected to the L2 and L5 cords, and a nylon monofilament with a diameter of 0.165mm is passed through the L3 and L4 cords as a connecting thread to connect the front and back ground structures. A 5.6 mm thick knitted fabric sheet was prepared. The mixture ratio of nylon monofilament with a yarn diameter of 0.165 mm in this sheet is 78.9% by weight, the fiber filling amount under no load is 18.1%, and the dynamic gradient is 0.03 (3%). permeability is no mounting load at 11cm / sec, 1kg / cm ² loading at 1.4cm / sec, 2kg / cm ² loading at 0.7cm / sec, 3kg / cm ² loading at 0.6cm / sec, 5kg / cm ^{(2) A} sheet-like drainage material having a three-dimensional thickness and excellent workability, having excellent water permeability, cushioning properties and impact resistance at the time of loading of 0.5 cm / sec was used.
[0035]
Lower water-impervious layer 9: a multi-structure, polyester 1000d / 192f high strength yarn (strength: 8.72kg / d, intermediate elongation at loading: 10.9%, elongation at break: 19.0%) and polyester spinning 120T / m combined twist of 1 single yarn, 120T / m 2 polyester 1000d / 192f high strength yarn (same as warp) and 2 single spun yarn of polyester 10 (same as warp) Excellent physical properties with a total thickness of 3.9, in which one side of a fabric cloth with a density of longitudinal x weft = 46 / 吋 x 46 / 吋 and a thickness of 2 mm using a twist is coated with polyethylene resin (LDPE) by calender coating ( JIS A 6022) Tensile strength = warp 305 kgf / cm, weft 315 kgf / cm, elongation at break = warp 910%, weft 898%, JIS L 1096 trabezoid tear strength = warp 117.0 kgf, weft 125.8 kgf, murren burst Test = 6 A resin composite water-impervious sheet also serving as a cushioning and impact-resistant protective layer 5 having a thick fiber layer on the back side having 0 kgf / cm ² or more) was used.
[0036]
The method of laying will be described in detail below. As a method of bonding between sheets, a commonly used prescription can be used. Use, a method of welding with a burner or the like, and a method of bonding sheets with an adhesive or the like.
[0037]
The materials created as described above are laid on the slope and bottom of the waste disposal site pit 2 in the order specified in the requirements of the present invention.
In the form parallel to the slope of the slope or bottom, with the resin coating surface of the resin composite water shielding sheet also serving as a protective layer on the bottom and the slope and bottom of the landfill pit 2 The adjacent sheet and the sheet edge are butted and laid, and on the butted part, a tape obtained by cutting the resin composite water shielding sheet used for the water shielding layer into a band of about 25 to 30 cm is stacked. Adhesion was performed using a heavy welder, and the entire waste disposal site pit 2 was formed as an integral water-impervious layer.
[0038]
Next, in order to introduce and drain the leachate 10 due to water leakage efficiently and promptly, the sheet-like drainage material of the drainage layer 8 is covered with the edge of the adjacent sheet and the sheet parallel to the slope and the bottom. Laying while covering.
[0039]
Next, a self-healing mat of the self-healing layer 7 is laid on the drainage layer 8 in a manner parallel to the slope of the slope and the bottom, with the edges of the sheets overlapped by 10 cm and covered. The joint was sealed with a 20 cm adhesive tape and laid as an integrated sheet.
[0040]
Next, the resin composite water-impervious sheet created with the water-impervious layer is placed on the sheet laid so far in parallel with the slope of the slope and the bottom, and the adjacent sheet and the sheet are overlapped by about 12 to 15 cm. And laid it over. Furthermore, the outer peripheral edge of the laid sheet was bonded to the lower water-impervious layer using a build-up type welding machine, thereby forming a bag structure including the self-healing layer 7 and the drainage layer 8.
[0041]
Finally, the polyester spunbonded nonwoven fabric sheet that will be the protective layer 5 is laid in a shape parallel to the slope of the slope and the bottom surface, with the edges of the adjacent sheets overlapped by about 10 cm and covered with a burner. The protective layer 5 of the sheet | seat which was welded and integrated was laid.
[0042]
When a hole of 3 mm in diameter penetrating the self-healing layer 7 was formed from the water-impervious layer and salt water was injected, the polymer water-absorbing resin of the self-healing layer 7 was absorbed and expanded to close the hole, and the water was stopped. Was confirmed. Furthermore, when salt water was injected by forming a 50 mm diameter hole penetrating the self-healing layer 7 from the water shielding layer, the salt water flowed down along the bottom gradient along the drainage layer 8 and quickly reached the end of the flow. It was confirmed that drainage was performed smoothly.
[0043]
In addition, this invention is not limited to the said embodiment, The suction means for attracting | sucking the leaching water 10 which leaked to the drainage layer, and promoting the leaching water 10 can also be provided. That is, the lower water-impervious layer 9 is composed of a lower water-impervious body divided into a plurality of predetermined sizes, and a base as a suction means (a metal or a resin is used) on the lower surface of each lower water-impervious body. Are formed, openings are attached to the openings, and vacuum suction devices are connected to the openings through suction hoses.
[0044]
In the water shielding equipment 1 having this configuration, the above-described materials are laid on the slope and bottom surface in the pit 2 in a specified order, and a partition and airtight structure capable of evacuation is obtained. Although the embodiment relating to the division and the airtight structure differs depending on the scale of the pit 1, the following two are conceivable.
[0045]
The lower water-impervious layer 9 excluding the openings necessary for drainage and vacuuming and the outer periphery of the two water-impervious sheets are bonded together by welding or the like, and the water-impervious sheet structure 3 is integrally and airtightly maintained in the bag body To do.
[0046]
Alternatively, the self-healing layer 7 and the drainage layer 8 are included in the bag body that is integrally airtight, parallel to the slope of the slope and the bottom surface, except for the openings necessary for drainage and vacuuming. It is installed by adhering a band-shaped partition made of a resin material or rubber material having a width of 10 to 100 mm and a thickness of 2 to 10 mm , or a water shielding sheet of the upper water shielding layer 6 and the lower water shielding layer 9 is welded. For example, lanes divided into a plurality of appropriately selected widths are provided for construction.
[0047]
Next, a base for connecting a suction hose is welded to an opening provided for drainage and vacuuming of the water-impervious sheet structure 3 that has become an airtight structure that can be evacuated as described above, or by an adhesive. By attaching and holding airtight, attaching a suction hose to the base, and connecting the suction hose to a vacuum suction device, it is excellent in impact resistance and durability, and when the upper water shielding layer 6 is damaged, The leachate 10 is blocked and repaired to prevent water leakage, or the leachate 10 that has leached into the drainage layer 8 due to water leakage is positively, reliably and quickly discharged by evacuation and has an extremely high safety barrier. It becomes water facility 1.
[0048]
【The invention's effect】
As is clear from the above description, the present invention is such that the water shielding sheet structure covers the pit in order to prevent the leachate from penetrating into the ground and to guide the leachate to a predetermined location. Since the water shielding structure provided is composed of the upper layer, the protective layer, the upper water shielding layer, the self-healing layer, the drainage layer and the lower water shielding layer in this order, the entire water shielding sheet structure is extremely robust and difficult to break. The risk of seepage of leachate into the ground is suppressed, and the constituent fiber material constituting the drainage layer has at least one of monofilament or monomultifilament, and the single yarn diameter is 0.14 mm or more. In addition, 30% by weight or more of the entire constituent fiber material is included, the fiber filling amount per unit volume when no load is set is 40% or less, and the thickness of the drainage layer 8 is set to 2 to 20 mm. Quick and reliable water Water can be guided to a predetermined place, and safety can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a water shielding facility in a waste disposal site showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Water shielding equipment 2 Pit 3 Water shielding sheet structure 4 Underground 5 Protective layer 6 Upper water shielding layer 7 Self-healing layer 8 Drainage layer 9 Lower water shielding layer 10 Leaching water

Claims (4)

  An impervious structure in a waste disposal site for preventing leachate from penetrating into the ground and guiding leachate to a predetermined place, The protective layer, the upper impermeable layer, the self-healing layer, the drainage layer, and the lower impermeable layer are formed in this order. Use a drainage layer in a waste disposal site, which contains 30% by weight or more of the entire fiber material, the fiber filling amount per unit volume when not loaded is 40% or less, and the thickness is 2 to 20 mm. Water shielding facilities. ^2. Waste disposal according to claim 1, wherein the in-plane hydraulic conductivity of the sheet-like fiber drainage material is 0.03 (3%) and 5 kg / cm2 when loaded, and the in-plane hydraulic conductivity is 0.1 cm / sec or more. Water shielding facilities using drainage layers at the site. The sheet-like fiber drainage material is a warp knitted fabric having an in-plane hydraulic conductivity of 0.1 cm / sec or more when loaded with a dynamic water gradient of 0.03 (3%) and 5 kg / cm ^2. Water shielding facilities using drainage layers at waste disposal sites in Japan.   The drainage layer in the waste disposal site according to any one of claims 1 to 3, wherein suction means for sucking leachate leaked into the drainage layer and promoting the drainage is provided. Water shielding equipment used.

Images