JP2001347242A - Water shielding structure of storage facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form water impermeable layer by grouting a solidifying material in the peripheral part of a broken part of a storage facility. SOLUTION: The water shielding structure 21 for storage facilities is constructed by excavating a place between hills to form a recessed part 2 to be a space for landfilling with municipal refuse and industrial wastes, laying a double water-shielding sheet 4 in the bottom face 3 of the recessed part 2, and covering the sheet with a protection mat 22. The protection mat 22 has a double layer structure composed of a permeable layer 23 in the lower layer side and an impermeable layer 24 in the upper layer side. The impermeable layer 24 is formed using, for example, non-woven fabrics so as to prevent elution of a hardening material and leakage of wastes, which are stored matters. On the other hand, the permeable layer 23 is formed by producing mesh sheets from, for example, a plastic material such as polypropylene resin, a polyethylene resin and the like, and layering the sheets in several layers based on necessity so as to suppress the compression degree to a slight level even if a heavy load owing to wastes is applied to and prevent crushing of the porous structure to be filled with the hardening material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water shielding structure provided on the bottom of a storage facility such as a waste disposal site.

[0002]

2. Description of the Related Art In a waste disposal site for landfilling industrial waste and general waste, it is extremely important to store waste for a predetermined period of time without hindering the preservation of living environment. . In order to do so, it is necessary to provide a predetermined waterproofing on the bottom surface of the disposal site so that harmful substances contained in the waste do not leach out as contaminated water and flow into the groundwater.

[0003] Such a water shielding work is usually composed of a water shielding sheet made of a soft synthetic resin, rubber, or the like. In recent years, there has been proposed a method in which the double water-impervious sheet is divided into a plurality of sections in advance so that only the damaged section can be repaired quickly (Japanese Patent Laid-Open Publication No.
6-63525 and 63526, etc.).

FIG. 6 shows an example of a water-blocking structure in which a double water-blocking sheet is divided into a plurality of sections. The water-blocking structure 1 shown in FIG. 1 is formed by laying a double water-blocking sheet 4 on the bottom surface 3 of a concave portion 2 formed by excavation in a mountain or the like, and covering a protective layer 5 made of sand thereon. . The double impermeable sheet 4 is the same
As can be clearly understood from (b), the lower sheet 6a and the upper sheet 6b disposed on the lower layer sheet 6a are arranged on the site side, and the lower sheet 6a and the upper layer sheet 6b are arranged vertically and horizontally. And divided into a plurality of grid-like sections.

On the other hand, the lower sheet 6a and the upper sheet 6
A space 7 is formed in each section between b. In the space 7, a mat 8 made of non-woven fabric is provided, and a pipe 9 for injecting a solidifying material such as cement bentonite is inserted. I have.

In such a water-blocking structure, the breakage of the double water-blocking sheet 4 is constantly monitored for each section, and if the damage of the double water-blocking sheet 4 of a specific section is confirmed, the section is rejected. The solidified material is injected into the corresponding space 7 via the pipe 9.

[0007] According to such a water impermeable structure, the solidified material only needs to be injected into the space corresponding to the damaged section, so that a large double water impermeable sheet can be repaired by using a minimum amount of the solidified material. Becomes

[0008]

However, as the amount of landfilled waste increases, a load corresponding thereto acts on the double water-impervious sheet 4, and the voids in the mat 8 formed of the nonwoven fabric are caused by the load. There has been a problem that the solidification material may not be filled with the crushing agent.

That is, no matter how much the solidifying material is injected through the pipe 9 in a state where there is no void in the mat 8, FIG.
As shown in (1), the water does not permeate the mat 8 and flows out through the damaged portion 10 to the outside. Further, since there is hardly any void in the protective layer 5 made of sand having a large amount of fine particles, the solidified material flowing out of the damaged portion 10 is transferred to the protective layer 5 near the damaged portion. It escapes further to the surroundings without penetrating, and as a result, an impermeable layer cannot be formed in the vicinity of the damaged portion 10.

The present invention has been made in view of the above circumstances, and provides a water shielding structure of a storage facility capable of forming an impermeable layer by reliably filling a solidified material in the vicinity of a damaged portion. The purpose is to:

[0011]

In order to achieve the above-mentioned object, according to the present invention, a water-blocking structure for a storage facility according to the present invention is provided in a space defined between an upper sheet and a lower sheet. In addition to laying a double impermeable sheet capable of injecting a solidifying material on the bottom surface of a concave portion formed in a mountain area or the like, and arranging a predetermined protective mat on the double impermeable sheet, In the water-shielding structure of the storage facility, a permeation layer having a void structure in which the protective mat is filled with the solidified material under a predetermined load is disposed below the protective mat, and the solidified material is formed above the protective mat. It has a two-layer structure in which an impermeable layer for preventing the outflow of water and the inflow of stored matter is provided.

[0012] In the water-blocking structure of the storage facility according to the present invention, a permeable layer through which the solidified material can penetrate is provided on the lower layer side of the protection mat, and the outflow of the solidified material and the inflow of stored matter are prevented on the upper layer side. An impermeable layer is provided. And the permeation layer
Even if a load due to a stored material such as waste is applied, the void structure in the permeation layer is maintained without being collapsed, and the filling property of the solidified material is maintained.

Therefore, when the solidified material is injected into the section of the damaged portion to repair the damage of the double impermeable sheet, the solidified material does not permeate into the double impermeable sheet and flows out of the damaged portion. Even so, the solidified material penetrates into the permeable layer of the protective layer and fills the void structure in the layer, forming an impermeable layer. The provision of the impervious layer prevents the stored material from flowing into the protection mat, so that the permeable layer of the protection mat is not clogged with the stored material.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the impermeable structure of a storage facility according to the present invention is applied to an impermeable structure of a waste disposal site will be described below with reference to the accompanying drawings. It is to be noted that the same reference numerals are given to components and the like that are substantially the same as those in the conventional technology, and description thereof will be omitted.

FIG. 1 is an overall sectional view and a partially enlarged view showing a water shielding structure according to the present embodiment.

The water-blocking structure 21 shown in FIG. 1 is formed by excavating a recess 2 serving as a landfill space for general waste and industrial waste in a mountain area or the like. Laying,
The protective mat 22 is coated thereon.

As can be seen clearly in FIG. 1B, the protective mat 22 has a permeable layer 23 on the lower side and an impermeable layer 24 on the upper side.
The impervious layer 24 is preferably made of, for example, a non-woven fabric so as to prevent the outflow of the solidified material and the inflow of waste as a storage material.

On the other hand, the permeation layer 23 is made of a plastic material such as polypropylene resin or polyethylene resin so that the compression amount is small even when an overload due to waste is applied and the void structure filled with the solidified material is not collapsed. It is preferable to form a mesh sheet by stacking several layers as necessary, for example, as shown in FIG.

Specifically, for example, a mesh sheet of high density polyethylene resin (trade name: diplanenetron sheet) formed by an extrusion molding method can be used. When such a mesh sheet is used, 50 t
It has been verified by a water permeability test using cement bentonite as a solidifying material that a water permeability coefficient of the order of 10 ^-1 cm / s can be secured even when an overload of / m ² is applied.

The permeable layer 23 and the impermeable layer 24 are
In order to reduce the laying work, it is preferable to bond them in advance.

The impermeable structure 21 of the storage facility according to the present embodiment
In the above, it is periodically monitored whether or not the double waterproof sheet 4 is damaged. As a method of monitoring, for example, a vacuum pump (not shown) is connected to the other end of the pipe 9, the pump is driven to evacuate the air in the space 7, and the degree of vacuum in the space 7 is measured by a sensor thereafter. . Here, if the degree of vacuum in the space 7 suddenly decreases, it can be determined that the lower sheet 6a or the upper sheet 6b corresponding to the space 7 is damaged.

When the damaged section is specified, as shown in FIG. 3 (a), a predetermined solidifying material, for example, cement-based material such as cement bentonite or mortar, is inserted into a space 7 corresponding to the section via a pipe 9. A solidifying material, an asphalt emulsion, a resin-based solidifying material, or the like is injected.

Then, the solidified material flows through the nonwoven fabric 8 as shown by the arrow in the figure, but when the load on the waste is relatively small, the solidified material penetrates into the nonwoven fabric 8 and fills it. There is an impermeable layer 31 as shown in FIG.
Are formed, and the damaged portion 10 is repaired.

On the other hand, when the overhead load caused by the waste is relatively large, the solidified material does not permeate the nonwoven fabric 8 but flows out of the damaged portion 10 as shown in FIG. However, even in such a case, the solidified material that has flowed out penetrates into the permeable layer 23 of the protective mat 22 and fills the voids in the permeable layer,
An impermeable layer 32 is formed as shown in FIG. The provision of the impervious layer 24 prevents the waste from flowing into the protection mat 22, so that the permeable layer 23 of the protection mat 22 is not clogged with the waste.

As described above, according to the water shielding structure of the storage facility according to the present embodiment, the permeable layer is formed in the protective mat so that the solidifying material can be filled under a predetermined load.
Even if the solidified material does not penetrate into the double waterproof sheet and flows out of the damaged portion, the solidified material penetrates into the permeable layer of the protective layer and fills the void structure in the layer, and Form a permeable layer.

Therefore, unlike the conventional case, there is no danger that the injected solidified material will escape to the surroundings through the damaged portion.
It is possible to reliably form the water-impermeable layer in the vicinity of the damaged portion and prevent leaching of contaminated water.

In the prior art where sand was used as a protective material, the work of laying the sand was rather large. However, the protective mat of this embodiment is composed of a nonwoven fabric and a plastic mesh sheet. Therefore, it is lightweight and easy to handle. Therefore, the workability at the time of laying is greatly improved.

In this embodiment, the permeable layer has a mesh-like structure. However, the permeable layer of the protective mat according to the present invention has voids filled with the solidifying material, and the overhead load caused by the waste is small. Any void structure may be adopted as long as the void does not collapse even when it acts. For example, a lattice-like void structure may be used, or a labyrinth structure in which wires are entangled irregularly.

In this embodiment, an example in which the present invention is applied to a waste disposal site is described. However, the present invention may be applied to a storage facility such as a simple reservoir, a reservoir, and a pool.

Further, in this embodiment, as can be seen from FIG. 2, it has been described that the void structure of the permeable layer 23 is uniform. However, the permeable layer of the protective mat according to the present invention has its void structure uniform in the cross-sectional direction. It is not necessary to keep the gap size large on the lower layer side and smaller on the upper layer side, for example.
The void structure may be changed in the cross section.

FIG. 4 shows a protective mat 41 having such a sectional structure. As can be seen from the figure, the protective mat 41 has a three-layer structure different from the above-described embodiment, and is provided between the permeable layer 23 and the impermeable layer 24 similar to the above-described embodiment. Also, another permeable layer 42 having a small void structure is sandwiched therebetween.

According to this configuration, while the penetration of the solidified material is adjusted and the load is dispersed by the permeable layer 42 having a small gap, the solidified material is sufficiently penetrated into the permeable layer 23 having a large gap to form the impermeable layer. It can be formed reliably.

It should be noted that the number of layers of the permeation layer may be increased to four or five, and the void structure distribution may be changed more minutely, or may be changed more continuously.

Although not specifically mentioned in the present embodiment, the protective mat may be divided into a plurality of sections, similarly to the double impermeable sheet.

FIG. 5 is a sectional view showing such a modification. As can be seen from the figure, the water-blocking structure according to the present modification also has a protection mat 54 laid on the double water-blocking sheet 50 as in the above-described embodiment. And the double impermeable sheet 50
Is provided with a mat 8 between a lower sheet 51 similar to the lower sheet 6a and an upper sheet 52 similar to the upper sheet 6b, and the protective mat 54 has the permeable layer 23 on the lower side and the impervious layer 23 on the upper side. An impermeable layer 53 similar to layer 24 is provided.

However, the double waterproof sheet 50 is different from the double waterproof sheet 4 in that the upper sheet 52 is replaced by the lower sheet 51.
The upper layer sheets 52 are adhered so as to overlap each other by a predetermined width, and a mat 8 is also provided at the overlapping portion. Further, the impermeable layer 53 of the protection mat 54 is adhered to the upper sheet 52 while overlapping each other at the overlapping portion.
Is divided into a plurality of sections in the same manner as. The permeation layer 23 is provided for each of the sections.

With this configuration, it is possible to repair the boundary between the divided sections by infiltrating the solidified material.

[0038]

As described above, according to the water shielding structure of a storage facility according to the present invention, a solidified material can be reliably filled in the vicinity of a damaged portion to form an impermeable layer.

[0039]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a water shielding structure of a storage facility according to the present embodiment, where (a) is an overall view and (b) is a partially enlarged view.

FIG. 2 is a perspective view of a permeable layer forming a part of the protection mat.

3A and 3B are diagrams illustrating the operation of the present embodiment, in which FIG. 3A illustrates a state where a solidifying material is filled, and FIGS. 3B and 3C illustrate a state where an impermeable layer is formed after the solidifying material is filled. FIG.

FIG. 4 is a cross-sectional view illustrating a water-blocking structure according to a modification of the embodiment.

FIG. 5 is a sectional view showing a water-blocking structure according to another modification of the embodiment.

FIGS. 6A and 6B are cross-sectional views of a water-blocking structure of a storage facility according to the related art, where FIG. 6A is an overall view, FIG. 6B is a partially enlarged view, and FIG.

[Explanation of symbols]

 4, 50 Double water barrier sheet 6a, 51 Lower layer sheet 6b, 52 Upper layer sheet 9 Pipe 21 Water barrier structure 22, 54 Protection mat 23, 42 Permeation layer 24, 53 Impermeable layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masao Kuroiwa 2- 15-2 Konan, Minato-ku, Tokyo Obayashi Corporation Tokyo head office (72) Inventor Kiyoshi Togawa 2- 15-2 Konan, Minato-ku, Tokyo Obayashi Corporation Tokyo head office F term (reference) 4D004 AA46 BB04 BB05

Claims (1)

[Claims] 1. A double water-impervious sheet capable of injecting a solidifying material into a space sandwiched between an upper layer sheet and a lower layer sheet for each predetermined section is laid on a bottom surface of a concave portion formed in a mountain section or the like, and In a water-shielding structure of a storage facility configured by disposing a predetermined protection mat on a heavy water-shielding sheet, a filling property of the solidifying material is maintained under a predetermined load on the lower side of the protection mat. A storage layer having a two-layer structure in which a permeation layer having a void structure is disposed, and an impermeable layer for preventing the outflow of the solidified material and the inflow of the stored material is disposed on the upper layer side. Impermeable structure.