JP3248437B2 - Waste disposal site and its construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inland waste disposal site constructed in a mountainous area or the like and a construction method thereof, and more particularly to a technique for improving the water shielding property.

[0002]

2. Description of the Related Art Inland-type disposal sites are known as landfill sites for industrial waste and household waste such as contaminated soil.
In this type of disposal site, a valley in a mountain is dammed to form a water-impregnated recess, and waste is dumped in this recess, or a flat terrain is excavated, There is a method in which an applied concave portion is formed, and waste is dumped in the concave portion.

[0003] In such a waste disposal site, as a water shielding work, for example, a method of laying a synthetic rubber or synthetic resin water shielding sheet on the inner surface of the concave portion, or a method of forming a reinforced concrete underground continuous wall. A method of building up to an impermeable layer is adopted.

[0004] However, such conventional waterproofing works include:
There were technical issues described below.

[0005]

That is, the conventional water barrier sheet and the water barrier of the underground continuous wall cannot completely stop the leaching of the contaminated water inside, and it is very little.
There is a problem that contaminated water seeps out and pollutes surrounding groundwater.

[0006] Such leaching of contaminated water becomes even more pronounced when the external groundwater level drops and becomes lower than the internal water level.

The present invention has been made in view of such a conventional problem, and an object of the present invention is to prevent leaching of contaminated water irrespective of external groundwater level fluctuation. It is to provide a waste disposal site that can be constructed and a construction method thereof.

Another object of the present invention is to provide a waste disposal site and a construction method for the same, which can easily detect leaching of contaminated water.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a water-impermeable outer connecting wall whose lower end is closed by an impermeable layer or a water-proof bottom plate, and an inner wall of the outer connecting wall. A water-blocking inner wall provided at intervals, and after excavating the inside of the inner wall, a water-blocking bottom plate provided to close the lower end thereof, and the inner wall is A waste disposal site for dumping waste in a recess separated by a bottom plate,
A water level sensor for detecting a water level between the outer and inner walls and a water level of the waste is installed, and a water level between the outer and inner walls is set to a water level of the waste based on a detection value of these water level sensors. A control device for water supply and drainage is provided so that it is always higher than the water supply. In addition, the present invention, at a predetermined interval from the ground, to form a water-shielding outer and inner connecting walls having a closed horizontal cross section,
After excavating the inside of the inner wall, a water-blocking bottom slab is formed by closing the lower end side of the inner wall, and waste is placed in a recess separated by the inner wall and the bottom slab. A waste disposal site for dumping, wherein the outer wall is formed so that a lower end thereof reaches an impermeable layer, or a bottom plate is formed after excavating the inside, and a lower end of the outer wall is formed. The water supply and drainage were performed so that the water level between the outer and inner communication walls was always higher than the water level of the waste. According to the waste disposal site constructed in this way and its construction method, water is supplied and drained so that the water level between the outer and inner walls is always higher than the waste water level. Also, contaminated water from waste is passed through external walls,
Leaching to the outside can be prevented. Also, by inspecting the water supplied and drained between the outer and inner walls, it is easy to determine whether or not contaminated water has leached.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 shows an embodiment of a waste disposal site according to the present invention. The waste disposal site shown in FIG. 1 is an inland type constructed on a flat ground, and has an outer connecting wall 10 and an inner connecting wall 12.

The outer and inner connecting walls 10 and 12 are reinforced concrete impermeable walls formed by an underground continuous wall method.
The horizontal cross section is formed in a closed square, circular, oval or the like, and the inner connecting wall 12 is formed in the same shape along the inside of the outer connecting wall 10 at a predetermined interval.

In the case of this embodiment, the outer connecting wall 10 is formed to a depth at which the lower end reaches the impermeable layer 16 in the ground 14, and is impermeable to water. On the other hand, the inner wall 12
Is located at the lower end of the water-permeable layer 18 above the water-impermeable layer 16.

The inside surrounded by the inner connecting wall 12 is excavated to the lower end thereof, and after excavation, a water-shielding bottom plate 20 is formed so as to close the lower end of the inner connecting wall 12. The waste 2 is placed in a recess 22 separated by the wall 12 and the bottom plate 20.
4 are discarded.

The portion surrounded by the outer and inner connecting walls 10 and 12 is
It is excavated to a predetermined depth, and a porous pipe 26 is installed, and is buried by filling with permeable crushed stone or plastic waste.

In this case, the hole for installing the pipe 26 is excavated without excavating the entire portion surrounded by the outer and inner connecting walls 10 and 12, and the pipe 26 is installed in the excavated hole. The outer periphery may be backfilled.

In a waste disposal site having such a structure,
The water level between the inner connecting walls 10 and 12 is controlled by the control device 28 so as to be always higher than the water level of the waste 24.

The control device 28 includes outer and inner connecting walls 10 and 12.
A first water level sensor 30 for detecting a water level between
A second water level sensor 32 for detecting the water level is connected, and a water supply and drainage pump 34, 36 for supplying and discharging water to the pipe 26 is connected.

The specific control performed by the control device 28 is as follows.
Based on the detection signals of the first and second water level sensors 30 and 32, when the water level of the waste 24 is higher than that between the outer and inner communication walls 10 and 12, the water supply pump 34 is driven to
6 is supplied with water to raise the water level between the outer and inner connecting walls 10 and 12.

The water level between the outer and inner connecting walls 10 and 12 is
Although the water level is higher than the water level of the waste 24, if there is too much difference between the water levels, water will enter the interior from between the outer and inner connecting walls 10 and 12, and in such a case, the drain pump 36
Is driven to discharge water from between the outer and inner connecting walls 10 and 12 so as to maintain a proper water level difference between the two.

When the water level between the outer and inner connecting walls 10 and 12 is controlled in this way, the water level between the outer and inner connecting walls 10 and 12 becomes higher than the inside regardless of the fluctuation of the external groundwater level. Due to the pressure difference, it is possible to reliably prevent the contaminated water from leaking out of the outer connecting wall 10 from the waste 24 side.

In the event that contaminated water is leached from the waste 24 side, the presence or absence of leaching of the contaminated water can be easily determined by inspecting the water supplied and drained between the outer and inner connecting walls 10 and 12. The following measures can be taken quickly.

Next, a construction method of the waste disposal site having the above-described configuration will be described with reference to FIGS. In constructing a waste disposal site, first, as shown in Fig. 2,
In 4, outer and inner connecting walls 10 and 12 are formed by an underground continuous wall method.

The outer and inner connecting walls 10 and 12 are both water-blocking, and are formed by excavating a rectangular slot, installing a reinforced cage, placing concrete, and hardening the concrete. It is formed by things.

The outer and inner connecting walls 10 and 12 are formed to have a closed horizontal cross section.
The inner wall 12 is formed to the depth of the water-permeable layer 18 above the lower wall without reaching the water-impermeable layer 16 at the lower end.

When the formation of the outer and inner walls 10 and 12 is completed, as shown in FIG. 3, excavation of the inside surrounded by the inner wall 12 is performed to the lower end side of the inner wall 12. . When the root excavation is completed, the bottom slab 20 is formed so as to close the lower end side of the inner connecting wall 12.

The bottom slab 20 is water-blocking and is made of reinforced concrete to a predetermined thickness. Inner wall 12
The excavation between the outer and inner connecting walls 10 and 12 is performed at the same time as the excavation of the inside of the inside or after the formation of the bottom plate 20 is completed.

When the excavation between the outer and inner connecting walls 10 and 12 is performed to a predetermined depth, a plurality of porous pipes 26 are installed between the outer and inner connecting walls 10 and 12 at a predetermined interval. Backfilling is performed by filling a permeable crushed stone or plastic waste between the outside of the pipe 26 and the hole wall.

The waste 24 is sequentially dumped into the recess 22 surrounded by the inner wall 12 and the bottom slab 20, and the outer and inner walls 10,
12, a first water level sensor 30 is installed in the recess 22, and a second water level sensor 32 is installed in the recess 22.
Water supply and drainage is performed via the pipe 26 so that the water level between 0 and 12 is always higher than the water level of the waste 24.

According to the waste disposal site constructed as described above and the construction method thereof, the outer and inner connecting walls 10 and 12 are constructed.
Water is supplied and drained so that the water level is always higher than the water level of the waste 24, so even if the external groundwater level fluctuates,
It is possible to reliably prevent the contaminated water of the waste 24 from passing through the outer connecting wall 10 and leaching to the outside.

Inspection of the water supplied and drained between the outer and inner connecting walls 10 and 12 makes it possible to easily determine whether or not contaminated water has leaked.

FIGS. 4 and 5 show another embodiment of the waste disposal site and the construction method according to the present invention.
The same reference numerals are given to the same or corresponding parts as in the above embodiment, and the description thereof will be omitted, and only the characteristic points will be described below.

The embodiment shown in FIG. 1 is employed when the depth of the water-impermeable layer in the ground 14 is very deep and it is difficult to form the lower end of the outer connecting wall 10 up to the water-impermeable layer.

In the waste disposal site of this embodiment, the outer and inner connecting walls 10, 12 formed in a rectangular shape or the like, the first bottom plate 20a corresponding to the water-impermeable layer 18 of the above-described embodiment, and the bottom plate 20 And a second bottom plate 20b.

The first and second bottom plates 20a and 20b are respectively water-blocking, and the first bottom plate 20a is formed so as to block and block both lower portions of the outer and inner connecting walls 10 and 12. ing. The second bottom plate 20b is formed above the first bottom plate 20a so as to block and block the lower side of the inner connecting wall 12.

Between the first and second bottom plates 20a and 20b, two first partition walls 38 are provided at equal intervals along the longitudinal direction of the inner connecting wall 12, and the first and second bottom plates are provided. 20
The portion between a and 20b is partitioned into three zones i to iii. On the extension of the first partition wall 38,
A second partition wall 40 is provided between the outer and inner connecting walls 10 and 12.

The second partition wall 40 is also provided at both ends in the short direction of the inner connecting wall 12, and a region between the outer and inner connecting walls 10, 12 is divided into eight zones iv to xi by the partition wall 40.
Is divided into

A plurality of through-holes 42 are provided in the short direction of the inner connecting wall 12, and the through-holes 42 allow the zone i to communicate with the zones vi and xi, and the zone ii and the zones vii and x And the zones iii and viii and ix are in communication.

As a result, the concave portion formed on the outer periphery of the inner connecting wall 12 is partitioned into five areas of zones i, ii, iii, vi, and v. Each zone i, ii, iii,
vi and v are excavated before forming the partition wall 40, the pipe 26 is installed, and the outside of the pipe 26 is backfilled with crushed stone or the like.

In the case of this embodiment, each zone i, i
The first water level sensor 30 is installed in each of i, iii, vi, and v, and each zone i, ii, iii, v
A water supply / drain pump is installed at i and v, and a second sensor 32 for detecting the water level of the waste 24 is installed.
Zones i, ii, iii, vi, v partitioned between 12
Is controlled individually so that the water level in the inside is always higher than the water level of the waste 24.

In the waste disposal site constructed as described above, the same operation and effect as those of the above embodiment can be obtained.
In this embodiment, the divided zones i, ii, iii, v
By inspecting the water supply and drainage of i and v, it is possible to know from which part of the inner communication wall 12 the contaminated water is leaching out, which can be used for subsequent repair measures.

In constructing the waste disposal site of this embodiment, the outer and inner connecting walls 10 and 12 are formed to the predetermined depth by the underground continuous wall method, and then the outer and inner connecting walls 10 and 12 are connected to each other. And the inside wall 12 is excavated to form a first bottom plate 20a, a first partition wall 38, and a second bottom plate 20b in this order, and zones i to i are formed.
After excavating inside ii, the second partition wall 40 is formed,
The pipe 26 may be installed and the outside thereof may be backfilled with crushed stone or the like.

After dumping the waste 24,
Zones i, ii, ii partitioned between the inner walls 10, 12
If the water level in i, vi, and v is controlled to be always higher than the water level of the waste 24, a disposal site where contaminated water does not leach to the outside is constructed even when the water-impermeable layer is very deep. be able to.

[0043]

As described above in detail in the embodiments,
ADVANTAGE OF THE INVENTION According to the waste disposal site and its construction method concerning this invention, the outside leaching of contaminated water can be prevented reliably.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing one embodiment of a waste disposal site according to the present invention.

FIG. 2 is a cross-sectional view showing a first step in a construction method of the waste disposal site shown in FIG.

FIG. 3 is a cross-sectional view of a step performed subsequent to the step of FIG. 2;

FIG. 4 is a top view showing another embodiment of the waste disposal site according to the present invention.

FIG. 5 is a sectional view of FIG. 4;

[Explanation of symbols]

 Reference Signs List 10 outer connecting wall 12 inner connecting wall 14 ground 16 impervious layer 20 bottom plate 20a first bottom plate 20b second bottom plate 24 waste 26 pipe 28 control device 30 first water level sensor 32 second water level sensor 36 water supply pump 38 drainage pump

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Katsumi Kotani 2-3, Kandajicho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo head office (56) References JP-A-4-34120 (JP, A) JP-A-Hei 7-119170 (JP, A) Japanese Utility Model Hei 5-67640 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B09B 1/00

Claims (2)

(57) [Claims] 1. A water-impervious outer connecting wall having a lower end closed by a water-impermeable layer or a water-shielding bottom slab, a water-permeable inner connecting wall provided at an interval inside the outer connecting wall, After excavating the inside of the inner wall, a water-blocking bottom plate provided so as to close the lower end thereof is disposed, and waste is dumped in a recess separated by the inner wall and the bottom plate. A waste disposal site, comprising a water level sensor for detecting a water level between the outer and inner communication walls and a water level of the waste; and a water level sensor for detecting the water level between the outer and inner communication walls based on a detection value of these water level sensors. A waste disposal site provided with a control device for supplying and discharging water so that the water level is always higher than the water level of the waste. 2. A water-impermeable outer and inner connecting wall having a closed horizontal cross section formed at a predetermined distance from the ground, and after excavating the inside of the inner connecting wall, a lower end of the inner connecting wall is formed. A waste disposal site that forms a water-blocking bottom plate by closing the side and dumps waste into a recess separated by the inner connecting wall and the bottom plate, wherein the outer connecting wall is The lower end is formed so as to reach the water-impermeable layer, or a bottom plate is formed after excavating the inside, so that the lower end side of the outer connecting wall is blocked by water, and the outer and inner connecting walls are closed. A method for constructing a waste disposal site, wherein water is supplied and drained so that the water level is always higher than the water level of the waste.