JP2004322018A - Method and system for promoting stabilization of landfill waste and permeated water capillary barrier layer - Google Patents

Abstract

An object of the present invention is to supply appropriate moisture to internal waste of landfill waste by multi-layer soil covering, and to discharge internally generated gas to the outside to promote stabilization.
An infiltration water capillary barrier layer is formed on an upper surface of a landfill waste with a gradient comprising a coarse-grained layer and a fine-grained layer laminated on the coarse-grained layer, and the gradient of the permeated-water capillary barrier layer is formed. A plurality of permeates are formed in the capillary barrier layer, in which a part of the permeated water that has been permeated and shielded in the lower landfill waste penetrates into the landfill while the drainage groove 36 is provided on the lower side to allow permeate water to be discharged. By dispersing and forming a portion, the generated gas generated inside the waste is exhausted from the degassing pipe 26 using the coarse-grain layer 18 constituting the capillary barrier layer, thereby stabilizing the landfill waste. .
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and system for promoting the stabilization of landfill waste and a permeated water capillary barrier layer, and in particular, stabilizes a landfill waste by controlling the amount of rainfall infiltration water into the landfill waste, The present invention relates to a method and a system for promoting stabilization of landfill waste and a permeated water capillary barrier layer suitable for preventing other excess rainwater from penetrating into landfill waste and preventing contamination of groundwater and the like.
[0002]
[Prior art]
Regarding general and industrial waste disposal methods, environmental pollution in the surrounding area of the disposal site has become a problem. This is that when infiltrated water such as rainfall infiltrates landfill waste, it is contaminated and flows into surrounding groundwater to be contaminated. Therefore, it is important to avoid contact between pollutants and groundwater in order to prevent environmental pollution. One of the preventive measures is a waste landfill structure using a multi-layer soil covering. FIG. 6 shows a longitudinal sectional view thereof. In FIG. 6, the multi-layered soil covering the surface of the waste is covered with the locally generated soil 2 by applying a gradient to the surface of the depression 1 and then laying the coarse-grained layer 3 and subsequently the fine-grained layer 4. Is formed, and finally the whole is covered with locally generated soil and topsoil 5 having good water barrier properties. Here, the layer boundary between the fine grain layer 4 and the coarse grain layer 3 has a gradient. This is because, by providing a fine-grained layer 4 composed of small grains and having a large water retention property on the upper layer of the large-grained coarse-grained layer 3 constituting the multilayered soil, the permeated water due to rainfall or the like is stopped at the fine-grained layer 4. At the same time, a capillary barrier is used, in which a soil gradient is applied to the soil cover to cause the soil to flow down along the interface between the coarse-grained layer 3 and the fine-grained layer 4.
[0003]
As a result, the infiltration water that has penetrated the fine-grained soil through the multi-layer soil cover surface and moved downward changes the flow direction along the gradient near the interface with the coarse-grained soil, and retains water in the fine-grained soil. While flowing down, water is collected and removed. For this reason, penetration of rainfall infiltration water and the like into the waste layer is prevented.
[0004]
[Patent Document 1]
JP 2001-17933 A
[0005]
[Problems to be solved by the invention]
However, after the completion of the landfill of such waste or after the closure of the disposal site, it is stipulated by law that water and gas generated from the disposal site are managed. In order to stop this management, it is necessary that the amount of leachate before treatment becomes lower than the value of drainage standard and the like, and gas generation and heat generation must be stopped. Such a state is called "stabilization". After landfill, complete the bottom impermeable layer, and if the possibility of environmental pollution to the surrounding area is small, rather than shut off moisture at all, moderate to stabilize the underground waste layer. In many cases, high moisture is required. In this case, a water injection pump is generally used as a conventional method, and there is an inconvenience that a power source is required in mountainous areas. In particular, it is necessary to chemically stabilize landfill waste at an early stage in order to make it harmless, but it is practically impossible to continue using power for a long period of time. . In addition, when performing aeration for stabilizing landfill waste, it is necessary to install equipment for aeration, and even in this case, an effective method has not yet been established.
[0006]
Further, since gas may be generated from landfill waste, a place for discharging this gas is required. In addition, it is necessary to promote gas stabilization by discharging gas generated from landfill waste and supplying air to the waste layer. In addition, the infiltration water needs to be drained, treated appropriately, and discharged to avoid reaching the bottom and staying there. Landfill waste also has rainwater and running water that flows into the landfill from the surroundings, so a trench is required to collect water on the surface.
[0007]
Thus, it is necessary to keep the underground waste in a stable and constant condition. According to the above-mentioned multilayer covering soil, the seepage water is drained along the gradient, and the inside of the landfill is blocked, which is not suitable for such a location.
[0008]
Therefore, the present invention has been made to solve the problems in the above-mentioned multi-layered soil covering, and does not particularly require a power source, and is capable of promoting the stabilization of landfill waste using natural resources. The aim was to provide a stabilization promoting method and system and a permeated water capillary barrier layer.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the method for promoting the stabilization of landfill waste according to the present invention is provided with a gradient comprising a coarse-grained layer formed on the upper surface of the landfill waste protection layer and a fine-grained layer thereon. Infiltration water is collected and drained on the gradient downstream side while shielding the infiltration water by the infiltration water capillary barrier layer, and a part of the infiltration water shielded by the infiltration water capillary barrier layer is contained in the landfill waste. It is characterized by stabilizing the landfill by dispersing and introducing a small amount. In addition, the wastewater treatment and the air supply from the lower part of the landfill waste may be performed.
[0010]
The landfill waste stabilization promotion system according to the present invention comprises a permeated water capillary barrier layer having a gradient formed of a coarse-grained layer and a fine-grained layer laminated on the upper surface of the landfill waste protection layer. A part of the permeated water permeated and shielded in the lower landfill waste is formed in the capillary barrier layer while forming a drainage groove on the lower side of the gradient of the permeated water capillary barrier layer so that the permeated water can be discharged. Dispersion and formation of multiple infiltration parts to introduce and permeate the landfill into the landfill, so that the penetration of the permeated water and the small amount of permeation into the landfill waste can be performed simultaneously to stabilize the landfill. Configuration.
Further, the permeated water capillary barrier layer has a multilayer structure along the gradient.
[0011]
In addition, the capillary barrier layer has a plurality of permeation portions for permeating part of the permeated water permeated and shielded into the lower landfill waste into the landfill. The barrier was provided.
In addition, a surface drainage ditch is formed on the surface of the soil covering layer laid on the upper surface layer of the landfill waste to collect and drain the flowing water flowing into the disposal site.
[0012]
In addition, by forming a degassing pipe that penetrates from the waste layer of the landfill waste to the surface of the covering soil layer and forms a degassing pipe that extends from the waste layer to the coarse-grained stone layer, the generation of a waste layer is achieved. The gas is discharged and the landfill is stabilized. The coarse-grained stone layer is provided with a coarse-grain-layer degassing promoting pipe in the coarse-grained stone layer.
[0013]
In addition, by forming a drainage drainage culvert with a gradient in the lower area of the waste layer of landfill waste and forming a drainage drainage culvert with holes, the wastewater in the waste layer is collected together with the water in the waste layer. The structure is such that air is supplied stably to stabilize the landfill.
The infiltration water capillary barrier layer of landfill waste forms a permeate water capillary barrier layer with a gradient consisting of a coarse-grained layer and a fine-grained layer laminated on the upper surface of the landfill waste protection layer, A nonwoven fabric was laid between the fine-grain layer and the coarse-grain layer forming the permeated water capillary barrier layer.
[0014]
In addition, the permeated water capillary barrier layer for landfill waste forms a permeated water capillary barrier layer with a gradient consisting of a coarse-grained layer and a fine-grained layer laminated on the upper surface of the landfill waste protection layer. The fine-grained layer or the coarse-grained layer was constituted by a pulverized material obtained by adjusting a particle size by pulverizing a solid material.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a method and a system for promoting stabilization of landfill waste and a permeated water capillary barrier layer according to the present invention will be described in detail with reference to the drawings.
In order to promote the stabilization of landfill waste, it is necessary to control the seepage of multi-layered soil due to rainfall, etc., to discharge excess seepage water, to secure appropriate water holding in the waste layer, and to generate gas generated inside the waste layer. To control the discharge of air and the supply of air. It also has a drainage function to reduce the amount of water flowing into the disposal site from around the landfill, and to prevent groundwater flowing from around the landfill from flowing through the impermeable layer.
[0016]
FIG. 1 is a sectional view showing the installation of the system for promoting the stabilization of landfill waste. The place where the waste 10 is landfilled is, for example, a landfill area by forming a depression using a gentle slope. Of course, it may be formed on flat ground. The impermeable layer 12 is laid on the mountain side slope, the bottom, and the left and right slopes of the depression. The material of the water impermeable layer 12 is not particularly limited as long as it can prevent water permeation. For example, impermeable soil that has the ability to retard the diffusion of harmful substances generated by mixing soil created by excavation of a depression and bentonite, a clay mineral that swells and comes into contact with water, making it very difficult for water to penetrate. May be laid in layers. The impermeable layer 12 is laid at the bottom of the depression, and is erected from the periphery thereof so as to rise upward along the mountain side and left and right slopes. This can prevent groundwater around the depression from entering the interior of the depression.
[0017]
The surface of the impermeable layer 12 is provided with a water conveyance gradient from the lower end of the slope on the mountain side to the valley side. A plurality of drainage culverts 14 are laid in parallel at appropriate intervals along this slope. The culvert 14 is formed by forming a large number of holes in the pipe wall, and collects water flowing out from the surrounding soil layer to flow downstream of the gradient. The culvert 14 connects to a water treatment facility 15 formed on the valley side. Thus, the sewage flowing through the culvert 14 is stored and purified.
[0018]
Next, the waste 10 is usually divided into sections and injected into the area where the impermeable layer 12 is laid. When the waste 10 is full for each section, the upper surface of the waste 10 is treated this time. A gradient is applied to the upper surface of the input waste 10 so that the surface of the waste 10 is set to a condition under which rainfall infiltration water easily flows down naturally. This gradient may be set in the direction of inclination of the gentle slope where the depression is formed, and may be set so that the inclination is made in the left-right direction from the ridge line along the center line of the depression. The upper surface of the waste 10 with the water introduction gradient is covered with a protective layer 16. The protective layer 16 can control the permeability as needed. Further, a so-called capillary barrier layer is laid on the top surface of the landfill waste protection layer 16. For this, first, a coarse-grained layer 18 having small water retention is laid on the lower layer side. The coarse-grained layer 18 may be formed of gravel, gravel, crushed stone, or the like. Next, a fine-grained layer 20 having high water retention is laid on the upper surface of the coarse-grained layer 18. The fine-grain layer 20 may be made of sand or the like having such a size that the infiltrated water can maintain a water retention state by the action of surface tension. As described above, the capillary barrier layer is provided with a fine-grained layer 20 composed of small particles and having a large water-retention property on the upper layer of the coarse-grained layer 18 having large particles. The water flows down along the interface between the coarse-grained layer 18 and the fine-grained layer 20 according to a gradient while being retained by the layer 20. As described above, the protective layer 16, the coarse-grained layer 18, and the fine-grained layer 20 are sequentially stacked on the upper surface of the waste 10, and are then covered with the covering layer 22. When the soil covering layer 22 is completely impervious to water, no water is supplied to the buried waste, and it takes an enormous amount of time to be stabilized. is necessary.
[0019]
In the present embodiment, a surface drainage groove 24 is provided in the covering layer 22 on the surface of the landfill in order to drain running water such as rainfall flowing from around the landfill. Here, it is predicted that the portion of the landfill where the waterfall deformation is greatest due to the groundwater fall is the depression with the largest landfill depth. Are arranged in the center. The drainage groove in the center may be a polyethylene pipe or a lightweight material drainage groove so as to follow the deformation. Depending on the installation location of the landfill, the surface drainage can be efficiently performed by branching a plurality of drainage grooves into branches and leaves around the surface drainage groove 24.
[0020]
Further, in order to drain the rainfall infiltration water that has been flooded from the surface of the soil covering layer 22, it can be drained laterally by using a multilayer soil covering composed of the fine grain layer 20 and the coarse grain layer 18. In this water collection, a drainage groove 36 is provided based on the drainage distance of the permeated water obtained from the water-blocking performance evaluation test of the multi-layered soil covering. That is, a simulated structure of the capillary barrier layer is created to determine the water retention limit distance (drainage distance) by the fine-grained layer 20, and if water is collected within a position corresponding to the drainage distance, landfill waste due to water retention destruction will occur. Excessive rainwater is prevented from penetrating into the inside.
[0021]
On the other hand, the gas generated from the waste is discharged to the outside by installing a gas vent pipe 26 projecting from the waste layer to the surface of the covering layer 22 and penetrating therethrough. In addition, a coarse-grained layer gas vent pipe 28 reaching the coarse-grained layer 18 from the waste layer is arranged. This is connected to a gas vent pipe 26 reaching the surface of the soil cover using a gap in the coarse-grained layer 18 to discharge gas to the outside.
[0022]
In addition, since the above-mentioned flow collecting culvert 14 has a relatively large cross section and is formed with a large number of holes formed in the pipe wall, contaminated water that has permeated from the soil covering surface and permeated through the waste 10 can be removed. It can collect water and supply air to the waste layer.
[0023]
Excessive infiltration water entering from the surface of the multi-layer soil cover may be drained laterally by the capillary barrier layer. FIG. 2 shows an installation sectional view of the drainage system for the capillary barrier layer. In FIG. 2, (a) shows a drainage system for a capillary barrier layer in which a gradient can be easily taken. (B) shows a drainage system for a capillary barrier layer having a gentler gradient than (a). (C) shows a drainage system for the capillary barrier layer on a flat ground with a small gradient.
[0024]
In the drainage system of the capillary barrier layer having a gradient shown in FIG. 2A, the capillary barrier layer is provided with a protective layer 16 on a waste (not shown), and a coarse stone 30, a fine sand 32, It is laid in the order of the covering soil 34. Drainage grooves 36 are installed in accordance with the drainage distance of the permeated water from the surface layer based on the water blocking performance evaluation test. The drainage groove 36 is a U-shaped groove of water-blocking, and coarse-grained stone 38 and coarse-grained stone 30 are spread on the bottom in order from the lower layer. A wall surface connecting the 30 layers and the coarse stone 30 at the bottom of the groove is formed. Further, fine-grained sand 32 connected to the fine-grained sand 32 layer is spread inside the groove.
[0025]
As a result, the rainfall or the like that has infiltrated from the surface of the waste landfill area passes through the covering soil 34 and flows down the boundary surface between the fine sand 32 and the coarse stone 30 according to the gradient. It flows into the fine sand 32 inside. Further, the coarse-grained stone 30 on the upper side of the downstream side of the vertical section of the drainage groove 36 is inclined to reduce permeation of permeated water into the lower layer. Coarse crushed stone 38 is installed at the bottom of the ditch so that water does not flow into the inside of the drain ditch 36, and a perforated pipe is installed at the bottom of the ditch to secure a drainage section if necessary, Drainage is possible. The drain 36 may be made of a rigid material such as concrete or resin as long as it has a water blocking effect. In addition, a water impermeable sheet 40 is disposed above the drain groove 36 as necessary. This is for preventing permeation of water at the end of the permeated water at a portion where water easily permeates into the lower layer, and the material of the permeated water is not particularly limited as long as it has a water blocking effect. Arrows in the figure indicate the direction of flow of water such as rainfall.
[0026]
FIG. 2 (b) shows a drainage system for a capillary barrier layer having a gentler gradient than that of FIG. 2 (a), and the configuration of the covering soil is the same as described above. In this case, the capillary effect cannot be expected because the gradient of the capillary barrier layer is gentle. Therefore, in order to secure the gradient and apply the lateral drainage, a stepwise gradient is provided on the downstream side of the drainage in the vertical section of the drainage groove 36. This gradient is arranged at a position higher than the drainage inlet on the upstream side, and has a structure in which permeated water flows into the drainage ditch when lateral drainage is performed. Further, the drainage groove 36 is installed at a position in consideration of the drainage distance based on the water-shielding performance evaluation test. The inside of the groove has the same configuration as described above, and a water impermeable sheet 40 is provided at the end of the flow of permeated water as necessary.
[0027]
While the drainage system described above works well in graded locations, it may be difficult to form gradients depending on where the waste is landfilled. In the drainage system for the capillary barrier layer on the flat ground in FIG. 2C, the configuration of the soil covering is the same as described above. If the capillary barrier layer does not have a one-sided slope in the above-mentioned flat ground, the slope between the drainage grooves 36 is formed in a mountain shape in order to form a slope in the capillary barrier layer, and the slope is positively inclined. Then, a drain groove 36 is provided at the valley portion and the end portion. The drainage ditch is installed at a location that takes into account the drainage distance (water retention limit distance). The inside of the groove has the same configuration as described above, and a water impermeable sheet 40 is provided at the end of the flow of permeated water as necessary. In this embodiment, the coarse crushed stone 38 is provided at the bottom of the drain groove 36 so as to prevent water from flowing into the inside of the drain groove 36. In addition, the coarse crushed stone 38 is not used. The layers may be spread as they are.
With this configuration, the leachate discharged from the surface layer is drained without coming into contact with the waste, so it is considered that there is almost no risk of contamination. Therefore, the water can be drained as it is like the surface drainage.
[0028]
On the other hand, in a capillary barrier layer in which the coarse-grained layer is the lower layer and the fine-grained layer is the upper layer, if the drainage distance of the rainfall or the like by the capillary barrier is too long, pore water cannot be retained, and there are places where permeated water falls. Rainfall, etc., that has fallen into the coarse-grained layer is more likely to penetrate further downward because there are gaps and little water retention. There are cases where the above-mentioned drainage ditch cannot be installed at this waterfall location. In addition, when forming a multi-layered soil, high-quality materials may not be used in some cases because of cost and the environment in which the materials are obtained. In some cases, the drainage distance cannot be increased depending on the material, and the drainage distance may be affected by the material (the type of sand) and affect the performance.
[0029]
Therefore, if a double structure is provided in which the permeated water capillary barrier layer having the coarse-grained layer 18 as the lower layer and the fine-grained layer 20 as the upper layer according to the drainage distance is further provided in the lower stage, the drainage distance can be prolonged or extended. It becomes. The structure of the multiplex type capillary barrier layer for reducing the falling of permeated water into the coarse particle layer 18 will be described with reference to the cross-sectional view of FIG. The protective layer 16 is laid on the waste layer 42, and the coarse layer 18, the fine layer 20, the coarse layer 18, the fine layer 20, and the cover layer 22 are laid on the protective layer 16 from the lower side in this order. The protective layer 16 and the covering layer 22 are formed of a material whose permeability can be controlled as necessary, and the permeability is controlled by appropriately combining a bentonite-mixed soil and a sheet.
[0030]
Further, a nonwoven fabric 44 may be provided at the boundary between the coarse-grain layer 18 and the fine-grain layer 20 forming the permeated water capillary barrier layer, if necessary. This is to prevent, for example, during the formation of the coarse-grained layer and the fine-grained layer from mixing between the fine-grained layer and the coarse-grained layer when the worker passes over the layer. That is, when the fine-grained layer and the coarse-grained layer are locally mixed, the water retention ability due to the capillary effect at that portion cannot be maintained, and the permeated water is prevented from falling.
[0031]
As a result, rainfall or the like permeates from the surface of the soil cover, moves laterally by capillary action of the fine grain layer 20 by the first capillary barrier layer composed of the fine grain layer 20 and the coarse grain layer 18, and can be drained. Even if the water falls into the lower layer after passing through, the second capillary barrier layer formed in the lower layer causes the fine-grained layer 20 to move laterally by capillary action. Since a certain amount of drainage is maintained even in the upper fine-grained layer, by forming the capillary barrier layer into a two-layer structure, it becomes possible to delay the rainfall that has fallen to the side. In addition, this capillary barrier layer may be installed at a place where the drainage distance is short, or the entire installation place may be a multilayer, depending on the installation place. Further, in the present embodiment, the case where the number of the capillary barrier layers is two has been described. However, the number of the capillary barrier layers may be two or more in accordance with the type of the coarse-grained layer and the fine-grained layer based on the method of evaluating the water barrier performance of the capillary barrier layer. You may comprise.
[0032]
Here, it is preferable that the sand used for the fine-grain layer 20 forming the permeated water capillary barrier layer be fine-grained sand. However, even if good quality materials cannot be obtained due to cost reduction, the above-mentioned shielding is required. Any ground material suitable for the capillary barrier layer based on the aqueous evaluation method may be used. For example, applicable secondary products such as crushed sand and crushed products, porous materials such as flocculent nonwoven fabric and sponge, or slag crushed products, crushed products of artificial products, textile products, plastic porous materials, ceramics, and sintered products A molded product or powder of a porous material, an aggregate of a powder material, a pulverized material of a porous material, an aggregate of a powder fluid of a porous material, and a powder of a raw material of a porous material can also be used instead. However, if the layers constituting the multi-layer are made thicker, they affect the capillary barrier, so it is desirable to use a material that can be made as thin as possible.
[0033]
FIG. 4 is a diagram showing a method for controlling the amount of permeated water in the capillary barrier layer. FIG. 4A is a side sectional view of the capillary barrier layer, and FIG. 4B is a plan view taken along line AA of FIG. 4A.
[0034]
In order to control the infiltration water into the waste layer, an entry port for infiltrating downward may be provided in a place where water is required in advance. Therefore, a hole into which permeated water enters may be formed at the boundary surface between the fine grain layer 20 and the coarse grain layer 18 of the capillary barrier layer laid on the upper surface of the waste layer (not shown). For this purpose, the flowing water surface along the boundary surface of the fine-grained layer is divided by the wall of the coarse-grained material and drawn into the downward sand layer. The position of the permeation hole may be determined by assuming the drainage area on the upstream side of the hole and estimating the permeation amount from the ratio of the drainage width and the hole diameter shared by the drainage ditch.
[0035]
In FIG. 4 (1), the gas vent tube 26 is a tube which has a T-shaped tip and which can penetrate from the waste layer to the surface of the multilayer covering soil including the capillary barrier layer, and has a T-shaped tip. A barrier 48 of the coarse-grained stone 30 is formed on the outer periphery of the gas vent tube 26. As a result, the permeated water that has permeated from the surface of the soil cover layer and has flowed due to the water conduction gradient at the interface between the fine-grained layer 20 and the coarse-grained layer 18 has coarse particles below the barrier 48 formed on the outer periphery of the degassing pipe 26. It penetrates layer 18 and penetrates further down the waste layer. Separately, in order to evenly infiltrate the landfill waste where water supply is required, the boundary between the fine-grained layer 20 and the coarse-grained layer 18 is provided on the downstream side of the water introduction gradient with coarse-grained water. A barrier 48 for the stone 30 is formed, and a sand hole 46 of the fine-grained layer 20 is provided upstream of the barrier 48. As a result, the permeated water that has permeated from the surface of the soil cover layer and has flowed due to the water conduction gradient at the interface between the fine-grained layer 20 and the coarse-grained layer 18 permeates the lower coarse-grained layer 20 at the sand holes 46 and the barrier 48. Then, it enters the waste layer 42 further below. Therefore, since the infiltration inlet of the infiltration water is secured by the outer peripheral portion of the degassing pipe 26 formed in the multi-layered soil and the sand hole 46, a part of the infiltration water that has infiltrated from the landfill surface can be reduced to a lower waste layer. Can be supplied to On the other hand, excess permeated water can flow into the drainage on the side following the water conveyance gradient and be collected by capillary action of the fine sand layer of the capillary barrier layer as before.
[0036]
FIG. 5 is a diagram showing a method of degassing the capillary barrier layer. The degassing of the waste layer may be performed by disposing a degassing pipe 26 that leads from the waste layer to the top surface of the soil cover. In addition, if a gas vent pipe extending from the waste layer to the coarse grain layer 18 is formed by utilizing the gap between the layers in the coarse-grained stone layer constituting the capillary barrier layer, the gas vent pipe is shorter than the gas vent pipe reaching the cover soil surface. Since it can be supplemented by pipes, the number of gas vent pipes that come out to the ground surface is reduced, making land use easier and at the same time reducing costs. If a ventilation volume is required, a perforated tube is placed in the wrought layer to improve ventilation.
[0037]
In FIG. 5, the multi-layered soil is constructed such that the protective layer 16, the coarse-grained layer 18, the fine-grained layer 20, and the soil-covering layer 22 are laid in this order on the surface of the waste layer (not shown). The degassing pipe 26 is a pipe that projects from the waste layer (not shown) and penetrates the surface of the covering soil layer 22 and has a T-shaped tip and can be ventilated from both ends of the pipe, and discharges gas generated in the waste layer to the outside. It is a mechanism to do. In the present embodiment, the shape of the degassing tube 26 is described as having a T-shaped tip, but the shape is not limited to this shape as long as it can be ventilated from both end surfaces of the tube.
[0038]
On the other hand, since the coarse-grained layer 18 forming the capillary barrier layer is made of coarse-grained stone, there is a gap between the stones in this layer. If this gap is used, the gas generated inside the landfill can be moved laterally and discharged to the outside via the gas vent pipe 26. Therefore, a tube extending from the waste layer to the coarse particle layer 18 may be formed. The coarse-grained layer gas vent tube 28 penetrates from the waste layer to the coarse-grained layer 18. Further, a hole through which the exhaust gas flows is formed on the surface where the gas vent tube 26 and the coarse particle layer 18 are in contact.
[0039]
As a result, the gas generated in the waste layer flows into the coarse-grained layer 18 through the gas release pipe 26 and the coarse-grained layer gas release pipe 28, and the gas release pipe is formed through the hole where the coarse-grained layer 18 and the gas release pipe 26 are in contact. 26, and can be discharged to the outside through a discharge port protruding from the surface of the covering soil layer. Also, the connection from the coarse-grain layer gas vent pipe 28 to the gas vent pipe 26 is performed by a perforated pipe or the like as required for air supply / exhaust, so that the coarse-grain layer gas vent pipe 27 is formed. A side exhaust pipe 29 extending to the portion may be provided.
[0040]
The following cases are considered for rainfall flowing into landfill waste.
1. Rainfall seeping from landfill surfaces
2. Surface water flowing into the landfill from around the landfill
3. Groundwater flowing from around the landfill
[0041]
Of these, with regard to 1, the amount of water can be reduced by the multilayer soil covering laid on the upper surface of the waste layer and the multilayer soil covering multiple layers. Regarding 2, by installing a surface drainage groove in the covering soil, which is the surface layer, it is possible to reduce the amount of water flowing in from around the landfill. Further, as for 3, the inflow of groundwater from the periphery can be reduced by covering the lower layer of the waste layer with the impermeable layer.
[0042]
【The invention's effect】
As described above, the present invention is directed to the downstream of the gradient while shielding the permeated water by the permeated water capillary barrier layer provided with a gradient composed of the coarse-grained layer formed on the upper surface of the landfill waste and the fine-grained layer thereon. Stabilize the landfill by systematically distributing and introducing a small amount of the shielded permeated water by the permeated water capillary barrier layer into the landfill waste. As it is configured to prevent water seepage and to simultaneously infiltrate a small amount into landfill waste, stabilization of the landfill is promoted. An excellent effect is obtained in that the layer itself can be constructed using natural materials and stabilization of landfill waste can be realized.
[0043]
In addition, while forming a gas vent pipe that penetrates the landfill waste from the waste layer to the surface of the covering soil layer, a gas vent pipe extending from the waste layer to the coarse-grained stone layer is provided, and a large distribution pipe is provided at the bottom of the waste layer. A water pipe was arranged to supply air. This makes it possible to supply appropriate air and moisture to the waste layer and discharge generated gas to promote oxidation, biodegradation, and the like, thereby promoting stabilization of the landfill.
[0044]
Further, by disposing the nonwoven fabric between the fine-grain layer and the coarse-grain layer forming the permeated water capillary barrier layer, mixing of the upper and lower layers can be prevented, and the water retention effect of the capillary barrier layer can be maintained. Furthermore, by using the fine-grained layer or coarse-grained layer constituting the permeated water capillary barrier layer as a pulverized material whose particle size has been adjusted by pulverizing a solid material, it can be used as an inexpensive alternative to recycled sand or a recycled product. The following can be used.
[Brief description of the drawings]
FIG. 1 is an installation sectional view of a system for promoting stabilization of landfill waste.
FIG. 2 shows an installation sectional view of a drainage system with a multi-layer soil covering.
FIG. 3 is a sectional view showing a multi-layered earth covering structure.
FIG. 4 is a diagram showing a method for controlling the amount of permeated water in the multilayered soil.
FIG. 5 is a view showing a method of degassing a multilayer covering soil.
FIG. 6 is a longitudinal cross-sectional view of a waste landfill structure using a multi-layer soil covering.
[Explanation of symbols]
1 ... recessed land, 2 ... local soil, 3 ... coarse-grained layer, 4 ... fine-grained layer, 5 ... topsoil, 10 ... waste, 12 ... Layer, 14… Drainage culvert, 15… Water treatment facility, 16… Protective layer, 18… Coarse grain layer, 20… Fine grain layer, 22… Soil layer, 24 surface drain groove, 26 gas vent tube, 27 gas vent tube in coarse-grained layer, 28 gas vent tube in coarse-grained layer, 29 lateral exhaust tube, 30 …… Coarse stone, 32 …… Fine sand, 34 …… Soil cover, 36 …… Drainage gutter, 38 …… Coarse crushed stone, 40 …… Water shielding sheet, 42 …… Waste layer , 44... Non-woven fabric, 46... Sand holes, 48.

Claims (11)

A gradient layer consisting of a coarse-grained layer formed on the upper surface of the landfill waste protection layer and a fine-grained layer on top of the layer is collected on the downstream side of the gradient while shielding the permeated water while shielding the permeated water. It is characterized by performing drainage, and stabilizing the landfill by dispersing and introducing a small amount of the shielded permeated water by the permeated water capillary barrier layer into the landfill waste to permeate a small amount. A method for promoting the stabilization of landfill waste. 2. The method for promoting stabilization of landfill waste according to claim 1, wherein wastewater treatment and air supply from a lower position of the landfill waste are performed. A graded permeated water capillary barrier layer consisting of a coarse-grained layer and a fine-grained layer laminated on top of it is formed on the upper surface of the landfill waste protection layer, and collected below the gradient of the permeated-water capillary barrier layer. A plurality of permeation parts for introducing and permeating a part of the permeated water permeated and shielded in the lower landfill waste into the landfill are dispersed in the capillary barrier layer while providing a water channel to allow permeated water to be discharged. A system for promoting stabilization of landfill waste, characterized in that by forming the same, simultaneous penetration of a small amount of water into landfill waste and shielding of permeated water are performed to stabilize the landfill waste. 4. The system for promoting stabilization of landfill waste according to claim 3, wherein the permeated water capillary barrier layer has a multilayer structure along the gradient. The capillary barrier layer includes a plurality of permeation portions for permeating part of the permeated water permeated and shielded in the lower landfill waste into the landfill, and includes a sand hole provided in the coarse-grain layer and a barrier provided in the fine-grain layer. The system for promoting stabilization of landfill waste according to claim 3, comprising: The system for promoting stabilization of landfill waste according to claim 3, wherein a surface drainage channel is formed on the surface of the soil covering layer laid on the upper surface layer of the landfill waste to collect and drain flowing water flowing into the disposal site. By forming a gas vent pipe that penetrates and penetrates from the waste layer of the landfill waste to the surface of the covering layer, and a gas vent pipe that extends from the waste layer to the coarse-grained stone layer, the gas generated in the waste layer can be reduced. 4. The system for promoting stabilization of landfill waste according to claim 3, wherein the system stabilizes the discharged landfill. The system for promoting stabilization of landfill waste according to claim 7, further comprising a pipe for promoting degassing in the coarse-grained layer in the coarse-grained stone layer. By forming a drainage culvert with a drainage gradient in the lower area of the landfill waste layer and forming a perforated drainage culvert, air is collected into the waste layer together with water collection in the waste layer. 4. The system for promoting stabilization of landfill waste according to claim 3, wherein the system is supplied stably to stabilize the landfill. A fine-grained layer that forms a permeated water capillary barrier layer with a gradient composed of a coarse-grained layer and a fine-grained layer laminated on the upper surface of the landfill waste protection layer, and forms the permeated-water capillary barrier layer A landfill waste permeated water capillary barrier layer comprising a nonwoven fabric laid between the layer and the coarse-grained layer. Forming an infiltration water capillary barrier layer having a gradient composed of a coarse-grained layer and a fine-grained layer laminated thereon on the upper surface of the landfill waste protection layer, wherein the fine-grained layer or the coarse-grained layer is a solid material; Water permeation water capillary barrier layer of landfill waste consisting of pulverized material whose particle size has been adjusted by pulverizing water.

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