JPH11226537A - Impermeable structure at waste disposal site - Google Patents

Abstract

(57) [Abstract] [Problem] To provide a tensile resistance to a water impermeable layer made of a soil impermeable material laid on a bottom ground of a waste disposal site, and to easily prevent cracks generated in the water impermeable layer. Provides a water structure. A water-blocking structure (10) installed over a bottom ground (12) of a waste disposal site (11) to prevent sewage from leaking from the inside of the disposal site (11) to the surrounding ground.
4 is formed of a water-impervious layer 16 formed by laying a soil impervious material 15 mixed with 4 on the bottom ground 12 with a predetermined thickness. Preferably, the impermeable layer 16 is formed on the bottom ground 1.
2 is laid on the upper surface of the impermeable sheet 13 provided so as to cover it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water impervious structure in a waste disposal site, and more particularly, to a structure installed over a bottom ground of a waste disposal site to prevent leakage of sewage from the inside of the disposal site to the surrounding ground. Regarding the impermeable structure to prevent.

[0002]

2. Description of the Related Art For example, landfill-type waste disposal sites for dumping industrial waste and general waste are disposed in a concave ground formed by utilizing natural terrain or excavating the ground. It is to be landfilled and stored, but it is mandatory to implement a seepage control in advance on the bottom ground of the disposal site in order to prevent environmental pollution due to the infiltration of sewage leached from landfill waste into the ground. I have.

[0003] As such a water-blocking work, conventionally, from the viewpoint of economy and water-blocking, water-blocking is provided by laying a soft synthetic resin-based or rubber-based water-blocking sheet. In addition, there is known a method in which a bottom layer of a waste disposal site is covered to form a water impermeable layer made of a soil impermeable material.

According to the method of forming a water-impervious layer with a soil-water-impervious material, these water-impervious layers are formed of a water-impervious earth material. If the grains are sufficiently contained, the generated soil is unwound and compacted to form a water-impervious layer.If the soil material is a soil mainly composed of sand, for example, bentonite may be added. It is common to form a water-impervious layer by compacting after making the material water-permeable.

[0005]

However, when the soil impermeable material is compacted into a water impermeable layer, the impermeable layer is strong against a compressive load but extremely weak against a tensile load. When the waste is injected into the disposal site and an imbalanced load is applied to the impermeable layer, especially when the bottom ground below the impermeable layer is weak, cracks are generated due to the tensile load due to subsidence etc. There is a problem that water leakage will occur.

Therefore, as a construction site of such a landfill site, a solid ground should be selected, or if the bottom ground is weak, the ground should be improved so that no sinkage occurs when the waste is charged. Although it is conceivable, it is difficult to select a solid ground suitable for a waste disposal site, and it will take enormous cost and construction work to improve the ground on soft and weak ground. There was a problem that.

Accordingly, the present invention has been made in view of such a conventional problem, and imparts tensile resistance to a water impermeable layer made of a soil impermeable material to easily prevent cracks generated in the water impermeable layer. It is an object of the present invention to provide a water impermeable structure in a waste disposal site that can perform the same.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and the gist of the invention is to cover the bottom ground of a waste disposal site and to install the surrounding ground from inside the disposal site. A water-blocking structure for preventing leakage of sewage to the water, comprising a water-blocking layer formed by laying a predetermined thickness of the soil water-blocking material mixed with short fibers on the bottom ground. It has a water-blocking structure at a waste disposal site.

[0009] In the water-blocking structure of the present invention, it is preferable that the water-blocking layer is laid on an upper surface of a water-blocking sheet provided so as to cover the bottom ground.

Here, the soil impermeable material for forming the water impermeable layer is a soil material capable of forming a water impermeable layer for preventing passage of water by forming a layer having a predetermined thickness. For example, silt or clay fine particles can be used, and even in the case of soil mainly composed of permeable sand, for example, by adding bentonite to improve water shielding, It can be used as a soil impermeable material.

As the short fibers to be mixed into the soil water-blocking material, preferably, synthetic fibers made of, for example, vinylon or polyester are cut to a length of about 5 to 10 cm. If the length of the short fiber is less than 5 cm, the frictional force with the soil is small and the effect of reinforcing the adhesive force and the tensile resistance is reduced, and if the length of the short fiber is longer than 10 cm, mixing with the soil is difficult. And lacks uniformity.

The thickness and amount of the short fibers to be mixed are appropriately designed in consideration of the effect of reinforcing the soil water barrier material and the like.

In order to mix such short fibers into the soil impermeable material, it is possible to use a soil mixer which is usually used for mixing soil. Centrifugal diffusion, to avoid
It is preferable to perform the mixing operation using a special high-speed mixer or the like utilizing the vortex principle.

Further, the work of laying the soil impermeable material on the bottom ground can be easily performed in the same manner as a normal leveling operation using a leveling compaction device such as a bulldozer. Here, the spread thickness is preferably, for example, 50 cm or more in consideration of the water blocking property and the like.

According to the impermeable structure in the waste disposal site of the present invention, the impermeable layer is formed by laying the soil impermeable material mixed with short fibers, so that the impermeable layer is stretched to the impermeable layer. Even if stress occurs, the short fibers will plastically resist this tensile stress and prevent cracking of the impermeable layer.

That is, according to the present invention, by mixing the short fibers into the soil impermeable material, the shear force and the tensile force applied to the soil by the frictional force between the short fibers and the soil are transmitted to the short fibers, and the tensile strength of the fibers is maintained. By exerting the strength as a resistance, the adhesive strength and the tensile force are added to the whole soil, and the toughness of the impermeable layer is increased, thereby preventing the impermeable layer from cracking.

Further, if such a water-blocking layer is laid on the upper surface of a water-blocking sheet provided to cover the bottom ground, a water-blocking function of the water-blocking sheet is added, and a more reliable water-blocking structure is provided. Will be constituted.

[0018]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The impermeable structure 10 in the waste disposal site according to this embodiment
As shown in FIG. 1, as an example, a large site in a mountainous area or the like is excavated in a concave shape, and is provided so as to cover a bottom ground 12 including a slope of a waste disposal site 11 created by leveling. It is a thing.

Then, the water shielding structure 1 according to this embodiment
Reference numeral 0 denotes a water-blocking sheet 13 provided so as to cover the bottom ground 12 and an soil water-blocking material 15 mixed with short fibers 14 on the upper surface of the water-blocking sheet 13 as shown in FIG. And a water-impervious layer 16 formed by laying.

Here, as the water-blocking sheet 13, for example, a soft synthetic resin-based or rubber-based sheet member can be used.
In 2, the bottom ground 12 is laid in a water-tight manner by welding and integrating in the vertical and horizontal directions.

The soil impermeable material 15 is made of silt or clay fine particles, and is compacted and rolled to a thickness of, for example, 50 cm or more to easily form a water impermeable layer 16 for blocking water passage. In addition, short fibers 14 for imparting tensile strength to the water-impervious layer 16 formed thereby are mixed in the soil water-impervious material 15.

The short fibers 14 are made of artificial synthetic fibers such as vinylon or polyester and have a length of about 5 to 10 cm. The short fibers 14 are mixed into the soil water-blocking material 15 and adhere to the soil itself by frictional force with the soil. A force and a tensile force are added to reinforce the whole soil. It is preferable that the short fibers 14 have a thickness of, for example, about 250 deniers, and it is further preferable that the short fibers 14 be mixed in about 0.3% with respect to the wet weight of the soil water barrier material 15.

The operation of mixing the short fibers 14 with the soil impermeable material 15 can be easily performed using, for example, a special high-speed mixer utilizing the principle of centrifugal diffusion and eddy current.

On the other hand, in order to form the impermeable layer 16 using such an impermeable material 15, the impermeable material 15 is loaded onto the upper surface of an impermeable sheet 13 disposed over the bottom ground 12. Then, by compacting and compacting using a bulldozer in the same manner as in a normal leveling operation, preferably 5
It can be easily formed with a thickness of about 0 to 100 cm.

According to the water-blocking structure 10 of this embodiment, the short fibers 14 are mixed in the soil water-blocking material 15 constituting the water-blocking layer 16, and a tensile stress is generated in the water-blocking layer 16. In addition, since the short fibers 14 plastically resist the tensile stress, for example, even if the bottom ground 12 of the waste disposal site 11 is weak and subsidence occurs when the waste 17 is charged, the toughness of the impermeable layer 16 is maintained. Therefore, the generation of cracks can be easily prevented, and therefore, the disposal site 11 can be economically constructed without improving the bottom ground 12.

Further, since the water-blocking layer 16 is formed on the upper surface of the water-blocking sheet 13 covering the bottom ground 12, even if the water-blocking layer 16 is cracked, the water-blocking sheet 13 blocks the water. The water function can reliably prevent water leakage to the outside.

The present invention is not limited to the embodiment of the above embodiment, but can be variously modified and adopted within the scope of the constitution described in each claim. For example, the water impermeable sheet 13 does not necessarily need to be provided, and the short fibers do not necessarily need to be artificial synthetic fibers.

[0028]

As described above in detail, according to the protection structure of the seepage control sheet in the waste disposal site of the present invention,
It is made up of a water-impervious layer formed by laying a predetermined thickness of soil impervious material mixed with short fibers on the bottom ground of the disposal site. As a result, cracks generated in the impermeable layer can be easily prevented.

Further, if the water-impervious layer is laid on the upper surface of the water-impervious sheet provided over the bottom ground, a more reliable water-impervious structure can be obtained by adding the water-impervious function of the water-impervious sheet. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating an example of a waste disposal site that employs a protection structure of a seepage control sheet of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG. 1 showing a configuration of a protection structure according to one embodiment of the present invention.

[Description of Signs] 10 impermeable structure 11 waste disposal site 12 bottom ground 13 impermeable sheet 14 short fiber 15 soil impermeable material 16 impermeable layer 17 waste

Claims (2)

[Claims] 1. A water-blocking structure that is installed over the bottom ground of a waste disposal site to prevent sewage from leaking from the inside of the disposal site to the surrounding ground. A water-blocking structure in a waste disposal site, comprising a water-blocking layer formed by laying a water material on the bottom ground with a predetermined thickness. 2. The impermeable structure in a waste disposal site according to claim 1, wherein the impermeable layer is formed on an upper surface of an impermeable sheet disposed over the bottom ground. .