JPH0154110B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for impermeability of waste disposal sites, particularly managed industrial waste final disposal sites, which prevents leaching of sewage for a long period of time.

``Prior art and its problems'' The disposal of incinerated ash and industrial waste generated as a result of daily life and industrial activities is becoming more and more strict year by year from the standpoint of pollution prevention. Although these wastes are required to be disposed of in accordance with their characteristics, the present invention mainly deals with waste that must be disposed of at a managed final disposal site, that is, there is no guarantee that the waste will be disposed of at a managed final disposal site. Insofar as this applies, it concerns the final disposal site for waste that cannot be removed from the factory by waste disposal companies. These managed final disposal sites are often located in mountainous areas, and form a large hole (landfill) with the ground on both sides of a valley and a cofferdam, and prevent sewage from entering groundwater on the surface of this landfill. After repeating the process of dumping waste into this layer and covering it with soil a predetermined number of times, soil is layered on top of the final dumped industrial waste and this waste is disposed of in a landfill. It is something that However, according to the lever method, whenever it rains, rainwater permeates through the soil and comes into contact with waste, producing sewage, regardless of whether the landfill is completed or not. In other words, not only during landfilling, but even after the final disposal site is filled, rainwater permeates through the soil and reaches the waste every time it rains, generating sewage each time, so sewage treatment is semi-permanent. It will have to be done for a longer period of time.

This costs a huge amount of money and is extremely problematic in ensuring continuity of responsibility. Therefore, there are restrictions on the effective use of reclaimed land. In addition, the water barrier layer is
Over the years, cracks have formed due to earthquakes, etc., causing problems such as sewage getting into the groundwater.

``Means for Solving the Problems'' This invention aims to provide a method of waterproofing a final disposal site, which prevents substantial seepage of sewage during and after landfilling, and is aimed at Waste is dumped and filled in the final waste disposal site, which consists of step-like steps formed at predetermined heights on the slope, drains formed at the bottom, and a water-blocking sheet laid inside. In the process of pressing and embanking into multiple layers,
A water-shielding sheet is applied directly to the top surface of the waste or through a cushion layer such as sand, and is applied at a water gradient to the surrounding drainage ditches formed at each step in the final disposal site to shield the waste from water. A water collection pipe for drainage and exhaust gas and a water permeable layer for preventing landslide phenomena are arranged on the upper surface of the water shielding sheet, and a water permeable layer is arranged to prevent landslides along with the water generating gas in each layer. The main idea is to remove the waste into the disposal site through water collection pipes and keep each layer dry.

"Embodiments" Next, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the final disposal site of the present invention, in which a water-blocking sheet 4 is stretched over the entire lower surface and slope of the reclaimed land surrounded by the ground on both sides of the valley and the cofferdam 2. A water collection pipe 7 for underground water consisting of a water collection main pipe 5 and a branch pipe 6 is buried below the water-shielding sheet 4, and the peripheral slope of the final disposal site is installed at intervals of 3 m in height. Flat parts 10a, 10b, 10c, 10d, 10
e, 10f, and drain grooves 8, 8a, 8b, 8c,
8d and 8f are arranged. The water-blocking sheet 4
The ends of these drainage grooves 8, 8a, 8b, 8c, 8
It is buried and fixed at the bottom of d, 8e, and 8f.
In addition, 8g in the figure is a rainwater drainage ditch formed on the ground surface, so that it will not be buried underground even after landfilling. The rainwater collected by the drainage ditches 8-8g is connected to the drainage ditches 8-8g, descends to the bottom along the slope in a step-like manner, and passes through the cofferdam 2 via the bottom of the drainage pipe. 27 and enters the wastewater treatment plant.

The waste 12a is dumped into the final disposal site as shown in FIG. When it rains on the dumped waste 12a, sewage is generated, so this waste 12a
It is preferable to immediately pressurize a to a predetermined height (approximately 3 m), and then cover the upper surface with a water-blocking sheet 11a with a water gradient so that rainwater flows into the drain 8a. In addition, even before filling, place sheet 1 on top of the same-day waste.
1a is preferably covered with a water gradient, and this will substantially prevent the generation of sewage during the landfill. By carrying out such partial landfilling, the entire bottom surface of the landfill is filled with waste 12a with a height of about 3 m and whose upper part is covered with a water-blocking sheet 11a. The water-blocking sheet 11a has a peripheral drainage groove 8.
The pipe is laid so that a water gradient is formed with respect to a, and a recess 28a is formed as shown in FIG. 4, and a porous pipe 29a is disposed in the recess. Note that the method of covering the top surface of the waste 12a with the water-blocking sheet 11a is not particularly limited as long as the end of the sheet 11a reaches the drainage groove 8a, but in the above embodiment,
A required number of bundled vinyl sheets are arranged so that their sides partially overlap, the ends of the sheets 11a are clamped and fixed between the porous pipe 9a and the drain groove 8a, and the bundled part is placed on the flat part 10a. After the waste material 12 is loaded, the vinyl sheet 11a is stretched and coated on the upper surface of the waste material 12a. Note that the overlapping portions of the sheets 11a may be joined by, for example, high frequency welding.

A layer of permeable gravel 30a is layered on the top surface of the water-blocking sheet 11a laid in this way, and then about 50 cm of soil 1 is layered.
Cover 3a with soil and apply pressure to prevent the soil from becoming uneven. Apply a water gradient to the filling pressure. Before covering with soil in this way, a perforated pipe 9a is installed in the drainage ditch 8a,
In order to prevent clogging of the perforated pipe 9a, the drain 8a
It is preferable to laminate a clogging prevention layer 20a made of pebbles 18 and sand 19 on top of the drainage ditch so that it can function as a drainage and gas vent even if the upper part of the drainage ditch is covered with soil 13a. In this case, the perforated pipe 9a may be replaced by other means for ensuring the drainage function, such as filling with a rectifier, and the clogging prevention layer 20a laminated on the perforated pipe 9a may also be formed by other known means. Of course it's good too.

Then, the waste 12b is dumped and compressed again on the top surface of the soil 13a, and the top surface of the waste 12b is covered with a water-shielding sheet 11b, and a covering layer 13b is formed on the top surface of the water-shielding sheet 11b via a permeable gravel layer 30b. let

Similarly, waste 12c, 12d, 12e,
Dumping of 12f, water-blocking sheets 11c, 11d, 11
Repeat steps e for laying and covering soil 13c, 13d, and 13e.

In the present invention, a final finishing layer is laminated on the top surface of the dumped waste as described above.
In the above embodiment, this finishing layer consists of a water-shielding sheet 22 that covers the top surface of the waste, a perforated pipe 30 disposed in a recess on the top surface of the water-shielding sheet 22, and a water-shielding sheet 22 that covers the top surface of the waste.
It consists of a water-permeable layer 23 laminated on the upper surface of the water-permeable layer 23, and finishing soil 24 that is laminated and compressed on the water-permeable layer 23. In the above embodiment, the finishing layer is leveled in three stages 24a, 24b, and 24c, and the finishing layer 24a is used to dump and pressurize the waste 12d, and the finishing layer 24b is used for discarding. The finishing layer 24c is applied after the material 12e is dumped and compressed, and the finishing layer 24c is applied after the waste material 12f is dumped and compressed.

The water-shielding sheet 22 may cover the waste directly, or may cover it with a cushion layer of sand, clay, or the like interposed therebetween. By providing such a cushion layer, the water-blocking sheet 22 is strongly protected.

The ends of the water-blocking sheet 22 are clamped and fixed between the porous pipe 9f and the drain hole 8f, and a clogging prevention layer 20f is laminated on the upper surface of the drain hole 8f, as in the case of the intermediate coating.

Water-permeable layer 23 laminated on the top surface of water-blocking sheet 22
has the function of preventing landslide phenomena.
That is, if the upper surface of the water-blocking sheet 22 is covered with soil, etc., when it rains, a layer of water will be formed between the water-blocking sheet 22 and the soil 24, and the upper soil 24 will be formed.
However, forming the permeable layer 23 in this way not only increases the coefficient of friction between adjacent layers, but also allows rainwater to flow from the permeable layer 23 through the drainage holes to the outside of the disposal site. This is because it is discharged. In addition, post-landfill waste 12a to 12f
The gas generated also reaches the sheet through the perforated pipe buried underground and the permeable gravel layer, but a portion of this gas is also discharged to the ground through the permeable layer 23.

As the permeable layer 23 for preventing landslide phenomenon,
In the above embodiment, chestnut stone, gravel, and sand are sequentially laminated. Although this does not necessarily have to be the case, it is better to stack multiple types of stones in such a way that they become smaller toward the top.

As shown in Fig. 4, a recess is formed in the final water-shielding sheet, and a perforated pipe 3 for underdrain drainage is formed in the recess.
0 is placed. The water slope of the final water-blocking sheet 22 is set so that rainwater flows into the drainage groove 8f and the porous pipe 30. This includes intermediate water-shielding sheets 11a, 11b, 11c, 11d, 11e and intermediate covering soil 13a, 13b, 13c, 13d, 13
The same applies to the case where a porous pipe is provided in case e.

In the above embodiment, the intermediate waste 12a,
Waterproof sheets 11a, 11b, 11c, 11d, 11e are also on the upper surfaces of 12b, 12c, 12d, 12e.
Intermediately coated with However, depending on the size of the final disposal site, if the landfill does not require a long period of time,
This is not necessary.

Intermediate water-shielding sheets 11a, 11b, 11c, 11
d, 11e and the final water-blocking sheet 22 are made of a water-impermeable material such as synthetic resin or rubber, and have high strength.
It is preferable to use a material used for this type of purpose, and in particular, it is preferable to use a material that is thick and strong for the final water-blocking sheet 22. In particular, it is preferable to use a plurality of agricultural sheets such as vinyl chloride, polyethylene, etc., which are used for greenhouses and should originally be thrown away, in a stacked manner from the viewpoint of resource saving and reuse of resources.

In addition, at the positions where the intermediate impermeable sheets 11a to 11c and the final impermeable sheet 23 reach the closing dam,
As shown in Figure 1, a perforated pipe 31 is placed on the water-blocking sheet
However, it is not necessary because these sheets form a water gradient so that rainwater flows into the drainage ditch of the disposal site.

In the above embodiment, perforated pipes are used as the permeable pipes installed on the top surface of the water-shielding sheet and in the drainage ditches, but this does not necessarily have to be the case and can be used for other purposes of this type. You may use whatever is used.

After being landfilled, it is completely blocked off with a water-blocking sheet, so rainwater does not seep into the final disposal site, so virtually no sewage is generated. However, although gas may be generated by the decomposition of waste, this is effectively removed from the ground through the perforated pipes and permeable layer, so there is no pressurized condition inside the final disposal site. It won't happen.

As mentioned above, after the landfill, rainwater does not permeate into the final disposal site, and the moisture inside the final disposal site is constantly discharged together with gas, both during and after the landfill, so the inside of the final disposal site is the same as the outside of the final disposal site. Since there is less moisture in comparison, even if a hole were to open in the water-shielding sheet, there is no risk of sewage flowing from inside the final disposal site to outside the final disposal site, and on the contrary, groundwater would flow into the final disposal site.

Rainwater collected by the drains and water collection pipes during and after the landfill is sent to a retention pond or a water treatment facility, where it is treated if necessary and then released.

As mentioned above, the landfill impermeability method of the present invention is mainly applied to managed industrial waste final disposal sites, but similarly, if the problem of sewage requires special attention from an environmental perspective, it can also be applied to general waste disposal sites. Of course, it can also be applied to disposal sites.

The final disposal site cleared in this way will be effectively used as a playground and cemetery.

"Effects of the Invention" As described above, according to the present invention, since a water-blocking sheet is laminated on the top surface of the final dumped industrial waste, it is possible to semi-permanently prevent rainwater from penetrating into the industrial waste. Since virtually no sewage is generated after landfilling, the enormous management costs associated with sewage treatment are significantly reduced or eliminated. Moreover, the landfill can be effectively used as a playground, etc., and a permeable layer is formed on the top of the impermeable sheet. As a result, rainwater is effectively drained and the risk of landslide phenomena is avoided.

In addition, the upper surface of the intermediate industrial waste is covered with a water-blocking sheet, and a water collection pipe and water permeable layer are installed.
It is possible to prevent the generation of sewage not only after the landfill but also during the landfill, and the long-term management costs associated with sewage treatment can be significantly reduced or eliminated.

Furthermore, the moisture content inside the final disposal site is extremely low compared to the area outside the final disposal site that faces through the water-shielding sheet, so even if a hole opens in the water-shielding sheet, sewage will flow from inside the final disposal site to the final disposal site. The fear of leakage outside the venue is avoided.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the waste disposal site water-blocking method of the present invention, Figure 2 is a cross-sectional view showing the landfill water-blocking method of the present invention, and Figure 3 is an enlarged view of part A in Figure 2. 4 is a sectional view taken along line 4-4 in FIG. 2. In the diagram, 2... Deadline, 4... Waterproof sheet,
7... Groundwater collection pipe, 8, 8a, 8b, 8c, 8
d, 8e, 8f...Drainage ditch, 10a, 10b, 1
0c, 10d, 10e, 10f...flat part, 11
a, 11b, 11c, 11d, 11e...Waterproof sheet, 12a, 12b, 12c, 12d, 12
e, 12f...waste, 13a, 13b, 13
c, 13d, 13e...Intermediate covering soil, 22...Waterproof sheet, 30a, 30b, 30c, 30d, 30
e... Permeable layer (permeable gravel layer), 22... Final impermeable sheet, 23... Water permeable/gas venting layer, 24...
Soil, 24a, 24b, 24c...finishing layer.

Claims (1)

[Claims] 1 Inside the final disposal site, steps are formed at predetermined heights on the peripheral slope of the final disposal site, drainage channels are formed at the bottom, and a water-blocking sheet is laid inside. In the process of dumping, compacting, and embanking waste to form multiple layers, a water-blocking sheet is formed on each step in the final disposal site, either directly on the top of the waste or through a cushion layer such as sand. The waste is sealed within the water-shielding sheet by covering the drainage ditch with a water gradient, and the upper surface of the water-shielding sheet is covered with drainage water and water.
A water collection pipe for exhaust gas, drainage water, and a permeable layer to prevent landslides are arranged together with the exhaust gas, and the water in each layer is removed along with the gas that generates to the outside of the disposal site through the permeable layer and the water collection pipe, and the inside of each layer is kept in a dry state. A water-blocking construction method for a final waste disposal site, which is characterized by: