JP3557957B2 - Repair method of existing waste disposal site - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for repairing an existing waste disposal site.
[0002]
[Prior art]
In the case of waste disposal sites that have been constructed for a long period of time, or that have been constructed before laws or regulations, or that have been disposed of as a result of illegal dumping, check that the bottom is not impermeable. Even if applied, it is often incomplete. In such a waste disposal site, groundwater contamination on the downstream side of the disposal site due to leaching water has become a social problem, and a technology for completely repairing or repairing this is required.
[0003]
As a method of repairing this type of existing waste disposal site, a water impervious wall is constructed by driving steel sheet pile along the outer periphery of the waste disposal site, cutting off the surrounding area, A method of injecting a chemical solution to solidify the bottom has been proposed.
[0004]
[Problems to be solved by the invention]
However, in this method, since the terrain and geology of the place composing the waste disposal site are often complicated, complete repair cannot be expected. In addition, the waste is in a state as it is, and the chemical solution is injected into the waste and solidified. Therefore, the waste becomes more anaerobic and the decomposition is delayed.
[0005]
On the other hand, it is conceivable to excavate all the waste and temporarily store it in another storage location and then apply a seepage control method. It requires a rather large site as an alternative land, and has issues such as securing the alternative land itself, preventing pollution of the alternative land, and making it difficult to use the former site due to the settlement of the alternative land, and the waste disposal site to be repaired. There is also the problem of transportation when the site is separated from the alternative site, and in practice, its implementation is extremely difficult.
[0006]
The present invention has been made to solve the above problems, and an object of the present invention is to make it possible to repair or renovate a waste disposal site sequentially without transferring the waste to another place while maintaining the current status. It provides a method for repairing existing waste disposal sites.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the method of the present invention is to partition an existing waste disposal site into a grid or a strip, construct a plurality of underground continuous walls reaching the lower ground, and construct a section surrounded by the underground continuous walls. After excavating and removing the wastes, the bottom of the section concerned is subjected to a seepage control. Therefore, according to the method of the present invention, the amount of waste in the section partitioned by the underground continuous wall is smaller than the amount of waste in the entire repository, and by excavating and transferring it to another section, the waste Repairs or renovations can be performed without having to be transported offsite. In addition, even in the case of transfer outside the disposal site, since the amount is small, the problem of the substitute site can be easily solved.
[0008]
Further, in the method of the present invention, the excavated and removed waste is transferred to another section in the disposal site or outside the disposal site, and after the impervious work is performed, the transferred waste is buried in the impervious section. By repeating the return in all sections, not only can the entire existing waste disposal site be impermeable, but also the decomposition of organic components due to the growth of aerobic bacteria due to the aeration effect during excavation and backfilling. Because it is promoted, it is suitable for early decomposition of waste.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the method of the present invention will be described in detail with reference to the accompanying drawings.
[0010]
In the present embodiment, an underground continuous wall is constructed in the waste disposal site 1 to partition it into a lattice shape (at an interval of about 3 to 10 m) in plan view. FIG. 1 shows a state in which a soil cement column 6 serving as an underground continuous wall is constructed by the SMW method using the heavy equipment 5, and the soil cement column 6 traverses a layer of the waste 3. It is constructed vertically so that the bottom reaches the lower ground E. As the underground continuous wall, another known underground continuous wall such as a steel sheet pile may be used instead of the soil cement column 6.
[0011]
After the above-mentioned underground continuous wall construction work is completed, as shown in FIG. 2, the shovel car 7 is thrown into one of the sections to excavate the waste 3, and, for example, pile up on the waste in the adjacent section. (The piled waste is shown by 3a and 3b). Then, when the excavation and removal of the waste accumulated in the section is completed, as shown in FIG. 3, the exposed surface of the ground E is subjected to a water impervious work 8, and the pile of the waste 3a is piled up in the adjacent section. , 3b into the same section and backfill. As the water shield 8, known materials such as a water shield sheet such as a rubber sheet, waterproof asphalt, and waterproof concrete can be employed.
[0012]
Thereafter, if the same work is repeated for each section one after another, as shown in FIG. 4, the entire bottom surface of the waste disposal site 1 is covered with the water shield 8, and the repair or repair work is completed. The amount of waste in the section partitioned by the soil cement column 6 is smaller than the total amount of waste in the repository 1, and is excavated and transferred to another section to be transferred outside the site of the waste repository 1. Repairs or renovations can be performed without having to do so. Oxygen is taken into the waste due to the aeration effect of excavation and backfilling, which promotes the activation of aerobic bacteria, and can promptly decompose organic components contained in the waste.
[0013]
In the present embodiment, the inside of the disposal site 1 is partitioned in a lattice shape. However, it is needless to say that the inside of the disposal site 1 may be partitioned in a strip shape or a streak shape. Further, in the above embodiment, the waste excavated in a certain section is piled up on the adjacent section, but may be a separate section instead of the adjacent section, or may be transferred to the outside of the waste disposal site 1. it can. Even in this case, since the amount of waste transferred is small, the problem of alternative land can be easily solved.
[0014]
In addition, a roof or the like can be constructed on the basis of the underground continuous wall formed by the soil cement column 6 or the steel sheet pile, and a storage in other parts in consideration of environmental conservation can be formed. Furthermore, a structure that does not sink can be constructed based on these underground continuous walls.
[0015]
【The invention's effect】
As is apparent from the above description, in the method for repairing an existing waste disposal site according to the present invention, the amount of waste in the section partitioned by the underground continuous wall is smaller than the amount of all waste, and Then, it can be repaired or refurbished without being transferred to a site other than the waste disposal site. In addition, even in the case of transfer outside the disposal site, since the amount is small, the problem of the substitute site can be easily solved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which a soil cement column that serves as an underground continuous wall is being constructed.
FIG. 2 is a cross-sectional view showing a state where one of the sections partitioned by the underground continuous wall is being excavated.
FIG. 3 is a cross-sectional view showing a state where a water shielding work is performed on the same section.
FIG. 4 is a sectional view showing a repair completed state.
[Explanation of symbols]
1 Existing waste disposal site 3 Waste 6 Underground continuous wall (column of soil cement)
8 Water shield

Claims (2)

The existing waste disposal site is partitioned into a grid or strip, a plurality of underground continuous walls reaching the lower ground are constructed, and the waste in the section surrounded by the underground continuous wall is excavated and removed. A method of repairing an existing waste disposal site, characterized by applying a seepage control to the existing waste disposal site. Transferring the excavated and removed waste to another section in the disposal site or outside the disposal site, and backfilling the transferred waste in the section subjected to the impervious work after the impervious work is performed in all the sections. The method for repairing an existing waste disposal site according to claim 1, wherein the method is repeated.

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