JP6507055B2 - Structure of bottom board impermeable structure and construction method of bottom board impermeable member - Google Patents

Description

  The present invention relates to the structure of a bottom board impermeable structure of a waste disposal site and a construction method of the bottom board impermeable apparatus.

  Conventionally, waste generated by activities at home and business sites is transported to a waste disposal site and disposed of after being subjected to volume reduction treatment such as incineration, crushing, compression and the like. FIG. 4 is a schematic view of a conventional waste disposal site 101. As shown in FIG. As shown in FIG. 4, the waste disposal site 101 is constructed in a recess provided in the underground 103. The water blocking layer 123 of the waste disposal site 101 includes, for example, a second water blocking layer 105 provided along the inner side surface of the recess and a first water blocking layer 107 provided inside the second water blocking layer 105. And the protective soil 109 provided on the inside of the first water blocking layer 107 (see, for example, Patent Document 1).

  The water blocking layer 123 prevents leakage of leachate and the like from the waste 111 discarded to the waste disposal site 101 to the ground 103, and the first water blocking layer 107 is provided with a protective mat or non-woven fabric. Water-impervious sheet protected by The second water blocking layer 105 may be a water blocking work with bentonite mixed soil created by mixing bentonite and site generated soil or purchased soil, or a cement modified soil created by mixing cement and site generated soil or purchased soil. A water shield is used.

  In the waste disposal site 101 as shown in FIG. 4, there may be a case where surface electrodes, line electrodes and the like (not shown) for identifying a damaged portion of the first water shielding layer 107 are embedded. When the damaged portion of the first water blocking layer 107 is identified by energization to this electrode, the protective soil 109 is excavated from the waste 111 side to expose the damaged portion, and the damaged portion is repaired. However, when the protective soil 109 is excavated to expose and repair the damaged portion of the first water impermeable layer 107, there is a possibility that the first water impermeable layer 107 may be further damaged due to an erroneous excavation depth. .

  FIG. 5 is a view showing an example of the cross section of the bottom board portion 113 of the waste disposal site. In the bottom board portion 113 shown in FIG. 5, the solidified material 115 of the waste material 111 made of incinerated ash settles at a certain depth and is deposited on the surface of the protective soil 109.

  In the example shown in FIG. 5, when the damaged portion 121 of the first water blocking layer 107 is specified, the hole 111 is gradually formed by boring while determining the type of soil to be discharged from the waste 111 side. Then, the protective soil 109 is detected after the solidified material 115 is detected, and it is determined that the depth of the boring has reached the upper surface of the protective soil 109. Thereafter, an inner pipe (not shown) is inserted into the pipe 117 installed in the hole 119, and the protective soil 109 is excavated in consideration of the known thickness of the protective soil 109 to repair the damaged portion 121 (for example, Patent Document 2) reference).

Unexamined-Japanese-Patent No. 10-277515 Japanese Patent Application Laid-Open No. 11-300308

  In the example of the bottom board portion 113 shown in FIG. 5, by detecting the solidified material 115, by controlling the digging depth of the protective soil 109, it is possible to prevent the further damage of the first water blocking layer 107. However, there is a problem that it takes time until the solidified material 115 is formed after discarding the waste material 111. In order to form the solidified material 115 early, it is conceivable to inject the infusate into the lower part of the waste 111 after discarding the waste material 111, but since the solidified material 115 is formed around the water collection pipe, it is discarded In addition to the possibility that the passage of water for stabilizing the object 111 may be inhibited and the treatment period of the waste 111 may be prolonged, it is expected that the construction is also difficult.

  Moreover, as shown in FIG. 4 and FIG. 5, when laying the sheet-like first water blocking layer 107 on the second water blocking layer 105 which is a soil water blocking layer, the reaction force of the ground 103 is small. It was difficult to compact the second water blocking layer 105 to a high degree of compaction. In addition, when the landslide 103 is landless, the thickness of the second water blocking layer 105 may be uneven. When the second water impermeable layer 105 had a portion with a poor rolling pressure or a portion having a non-uniform thickness, the sheet-like first water impermeable layer was prone to wrinkles, and welding failure was likely to occur.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to grasp the digging depth at the time of repairing the impermeable sheet and to prevent breakage of the impermeable sheet due to excessive excavation, It is the construction of the bottom impermeable structure without influence on the water collection performance of the water collection pipe and the construction method of the bottom impermeable structure.

In order to achieve the above-mentioned object, the first invention is a structure of a bottom board of a waste disposal site, comprising a water blocking sheet, a protective soil disposed above the water blocking sheet, and the protection bottom panel water shield characterized by comprising the treated soil layer that will be formed by the surface layer of the upper surface of the soil the protective earth to cement improved, and water collecting pipe installed on the upper surface of the treated soil layers, the It is the structure of work.

In the bottom impermeable layer of the first invention, the stabilized soil layer is installed on the upper surface of the protective soil, so when excavating the bottom impermeable structure from the waste side and repairing the impermeable sheet, the stabilized soil By detecting the existence of the layer, it can be understood that the excavation of waste has been completed. This makes it possible to prevent damage to the impermeable sheet due to excessive excavation of the protective soil. Moreover, since the water collection pipe is installed on the upper surface of the stabilization treated soil layer, the water permeability around the water collection pipe is secured. If the surface layer of protective soil is cement-modified, a stabilized soil layer can be easily formed.

According to the first aspect of the present invention, the structure of the bottom board impermeable body comprises a soil impermeable layer installed below the impermeable sheet, and a bottom base layer installed below the soil impermeable layer, as needed. In addition,
If the bottom base layer is installed on the lower surface of the soil impermeable layer, it is possible to obtain a reaction force from the bottom base layer and compact the soil impermeable layer to a high degree of compaction. In addition, even when there is landfall on the ground, it is possible to prevent the rolling failure of the soil impermeable layer.

The treated soil layer is preferably stronger than waste discarded waste treatment plant is large.
To be greater than waste the strength of stable treated soil layer, when drilling bottom panel water shield Engineering from waste side for repairing the water shield sheet can be easily detect the treated soil layers.

The bottom base layer is, for example, a concrete board, and in some cases, anti-cracking reinforcing bars are embedded in the concrete board.
By embedding anti-cracking reinforcing bars in a concrete block, it is possible to prevent the cracking of concrete and ensure the reaction force at the time of compaction of the soil impermeable layer.

  The second invention is a construction method of bottom board water shielding construction of a waste disposal site, which comprises a step a of laying a water shielding sheet, a step b of installing a protective soil above the water shielding sheet, and the protection A step c of forming the stabilized soil layer by cement-reforming the surface layer of the soil, and a step d of installing a water collection pipe on the upper surface of the stabilized soil layer; It is a construction method.

  In the second invention, in order to install the stabilized soil layer formed by cement-reforming the surface layer of the protective soil on the upper surface of the protective soil, excavating the bottom water shield from the waste side and repairing the water shielding sheet In this case, by detecting the presence of the stabilized soil layer, it can be easily grasped that the excavation of waste has been completed. This makes it possible to prevent damage to the impermeable sheet due to excessive excavation of the protective soil. In addition, since the water collection pipe is installed on the upper surface of the stabilization treated soil layer, the permeability of the periphery of the water collection pipe is secured.

  In the second invention, the method further includes a step e of installing the bottom base layer on the ground and a step f of installing the soil water impermeable layer on the top surface of the bottom base layer before the step a, In the step a, it is desirable to lay the water blocking sheet above the soil water blocking layer.

  If a bottom foundation layer is installed on the ground and a soil impervious layer is installed on the top surface, it is possible to obtain a reaction force from the bottom foundation layer and compact the soil impermeable layer to a high degree of compaction. In addition, even when there is landfall on the ground, it is possible to prevent the rolling failure of the soil impermeable layer.

  According to the present invention, it is possible to grasp the drilling depth at the time of repair of the water blocking sheet and prevent damage to the water blocking sheet due to excessive excavation, and there is no influence on the water collection performance of the water collection pipe. And can provide a construction method of bottom board water shield.

A figure showing a vertical cross section of the bottom board impermeable structure 1 Top view of concrete board 11 Figure showing an example of the vertical cross section of another basement A diagram showing an outline of a conventional waste disposal site 101 Figure showing an example of the cross section of the bottom plate 113 of the waste disposal site

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a view showing a vertical cross section of the bottom board water shield 1. As shown in FIG. 1, the bottom board water blocking construction 1 is stabilized with a water blocking sheet 7, a protective soil 5 installed above the water blocking sheet 7, and a stabilized treated soil layer 3 installed on the upper surface of the protective soil 5. Water collecting pipe 15 installed on the upper surface of treated soil layer 3, soil water shielding layer 9 installed below water shielding sheet 7, concrete board 11 which is a bottom base layer installed on the lower surface of soil water shielding layer 9, etc. It consists of

The water blocking sheet 7 prevents leakage of leachate from the waste 17 to the ground 13. The water-impervious sheet 7 is, for example, a sheet having a very low water permeability coefficient and water blocking. A protective mat (not shown) is provided on the upper surface of the water blocking sheet 7.
The protective soil 5 prevents damage to the water-impervious sheet 7 and is formed of a high quality sediment layer. The thickness of the protective soil 5 is, for example, about 70 cm.

  The stabilized soil layer 3 is formed, for example, by cement-reforming the surface layer of the protective soil 5. The stabilized soil layer 3 is assumed to be stronger than the waste 17 discarded in the waste disposal site. Stabilized soil layer 3 may have water permeability. The thickness of the stabilized soil layer 3 is, for example, about 30 cm. The standard of the strength of the stabilized soil layer 3 is uniaxial compression strength qu = 300 to 500 kPa. The water collection pipe 15 collects water leached from the waste 17 and is coated with a permeable material 16 having water permeability.

  The soil water impermeable layer 9 is a water impermeable layer, and like the water impermeable sheet 7, prevents leakage of leachate. The soil impermeable layer 9 is, for example, a bentonite mixed soil prepared by mixing bentonite and in-situ generated soil or purchased soil, or a cement modified soil prepared by mixing cement and in-situ generated soil or purchased soil. The soil impermeable layer 9 has a thickness of, for example, about 50 cm, and can follow the displacement of the ground 13 up to about 10 cm.

  The concrete board 11 is installed on the ground 13. In the concrete board 11, a crack preventing reinforcing bar is embedded. The thickness of the concrete board 11 is, for example, about 20 cm, which is the minimum thickness at which the anti-cracking reinforcing bars are disposed and finished evenly. FIG. 2 is a plan view of the concrete board 11. As shown in FIG. 2, a joint 21 is appropriately provided on the concrete board 11. The concrete disc 11 may be a pre-cast member, but in order to improve the familiarity with the ground 13, it is desirable to form by casting.

  A water leakage detection system 19 consisting of an electric wire 19a and an electric wire 19b is installed in the bottom board water shield 1. The electric wire 19 a is buried in the protective soil 5 on the waste 17 side of the water blocking sheet 7. The electric wire 19 b is buried in the soil water impermeable layer 9 on the ground 13 side of the water impermeable sheet 7. The electric wire 19a and the electric wire 19b are arranged orthogonal to each other in a lattice shape.

  Next, the construction method of the bottom board water blocking construction 1 will be described. In order to construct the bottom board water blocking construction 1, first, the concrete board 11 in which the anti-cracking reinforcing bar is embedded is installed on the ground 13, and the unevenness of the ground 13 is adjusted. Then, the soil water impermeable layer 9 is installed on the upper surface of the concrete board 11. When compacting the soil impermeable layer 9, a reaction force is secured from the concrete plate 11. In the vicinity of the surface layer of the soil impermeable layer 9, the electric wire 19b of the water leak detection system 19 is embedded.

  Next, the water blocking sheet 7 is laid above the soil water blocking layer 9, and the protective soil 5 is placed above the water blocking sheet 7. Near the bottom layer of the protective soil 5, the wire 19a of the water leak detection system 19 is embedded. Thereafter, the surface layer of the protective soil 5 is cement-modified to form the stabilized soil layer 3. Furthermore, a water collection pipe 15 coated with a covering material 16 is installed on the upper surface of the stabilized soil layer 3.

  In the bottom board water shielding construction 1, when the water shielding sheet 7 is broken, the electric wire 19a and the electric wire 19b of the water leakage detection system 19 are short-circuited to detect the water leakage. When a water leak is detected, the bottom board water shielding construction 1 is excavated from the waste 17 side, and the damaged portion of the water shielding sheet 7 is repaired.

  In order to repair the damaged portion of the water blocking sheet 7, excavation is started from the waste 17 side with heavy machinery. When the excavation reaches the stabilized soil layer 3 having a predetermined strength, it can be recognized that the excavation of the waste 17 is completed due to the difference in strength between the waste 17 and the stabilization soil layer 3. Thereafter, the protection soil 5 is excavated to a depth suitable for repair of the water blocking sheet 7 in response to switching to manual excavation and the like.

  In order to recognize that the drilling has reached the stabilized soil layer 3, the Geotechnical Engineering Standard (draft) portable cone penetration test (JGS 1431-2003) may be conducted. As described above, the standard of the strength of the stabilized soil layer 3 is uniaxial compressive strength qu = 300 to 500 kPa. Since there is a relationship of qc ≒ 5 × qu between the uniaxial compressive strength qu and the cone index qc, the standard of the cone index qc of the stabilized soil layer 3 is 1500 to 2500 kPa.

  As described above, in the present embodiment, in order to install the stabilized soil layer 3 having a strength greater than that of the waste 17 on the upper surface of the protective soil 5, the water shielding sheet 7 is repaired by excavating from the waste 17 side. When the waste 17 and the stabilized soil layer 3 are different in strength, it can be recognized that the stabilized soil layer 3 on the protective soil 5 is reached. Thereby, damage to the water blocking sheet 7 due to excessive excavation of the protective soil 5 can be prevented. The stabilized soil layer 3 is easily formed by cement-reforming the surface layer of the protective soil 5.

  In the present embodiment, after forming the stabilized soil layer 3 having a strength greater than that of the protective soil 5, the heavy machine is installed on the stabilized soil layer 3 to construct the water collection pipe 15, so the shear force of the heavy machine It is hard to be transmitted to the water sheet 7, and the water blocking sheet 7 is hard to break. In the present embodiment, since the water collection pipe 15 is installed on the upper surface of the stabilized soil layer 3, the periphery of the water collection pipe 15 is compared with the conventional method of grasping the arrival of excavation by solidified matter in the lower layer of waste. Permeability of water can be secured and it is easy to collect water.

  In the present embodiment, the concrete board 11 is installed on the upper surface of the ground 13, and the soil water impermeable layer 9 is installed on the upper surface of the concrete board 11. By installing the concrete board 11, it is possible to adjust the landslide 13 of the ground. Moreover, a reaction force can be reliably obtained from the concrete board 11, and the soil water impermeable layer 9 can be uniformly compressed to a high degree of compaction. If the anti-cracking reinforcing bars are embedded in the concrete board 11, the strength of the concrete board 11 can be further enhanced.

  In the present embodiment, the crack can be controlled by providing the joint 21 on the concrete board 11. Moreover, the area which completed the installation at the time of construction of the soil impermeable layer 9 can be easily managed by the concrete board 11 being divided by the joint 21.

  In the present embodiment, the bottom board water shield 1 is configured as shown in FIG. 1, but the structure of the bottom board water shield according to the present invention is not limited to this. FIG. 3 is a view showing an example of the vertical cross section of another bottom board water shield.

  In the bottom board water shielding construction 1a shown in FIG. 3 (a), instead of the water shielding sheet 7, a two-layer water shielding sheet 7a and a water shielding sheet 7b are disposed. The water-impervious sheets 7a and 7b are provided with protective mats such as short fiber nonwoven fabric 23 on the upper and lower surfaces, respectively. An intermediate protective soil 25 having a thickness of about 30 cm is provided between the short fiber nonwoven fabric 23 on the lower surface of the water blocking sheet 7a and the short fiber nonwoven fabric 23 on the upper surface of the water blocking sheet 7b.

  In the bottom board water blocking construction 1b shown in FIG. 3 (b), another water blocking layer 27 such as asphalt concrete is provided below the water blocking sheet 7 instead of the soil water blocking layer 9. The lower part of the impermeable layer 27 is the ground 13 and the concrete board 11 is not provided.

  In the same manner as the bottom board water blocking work 1 shown in FIG. 1, the bottom board water blocking work 1a shown in FIG. 3 (a) and the bottom board water blocking work 1b shown in FIG. By installing the formed stabilized soil layer 3 on the upper surface of the protective soil 5, when drilling from the waste 17 side and repairing the water blocking sheet 7, the stabilized soil layer 3 on the protective soil 5 was reached It can be easily recognized that damage to the water-impervious sheet 7 due to excessive excavation of the protective soil 5 can be prevented. In addition, since the water collection pipe is constructed after the formation of the stabilized soil layer 3, the shear force of the heavy equipment is less likely to be transmitted to the water blocking sheet 7, and the water blocking sheet 7 is less likely to be damaged.

  In the present embodiment, the surface layer of the protective soil 5 is cement-modified to form the stabilized soil layer 3, but the method of forming the stabilized soil layer 3 is not limited thereto. Stabilized soil layer 3 may be any material as long as it can recognize the boundary between waste 17 and protective soil 5, and may color the surface layer of protective soil 5 or spill white soil on the upper surface of protective soil 5. You may form.

  In the present embodiment, the concrete board 11 having anti-cracking reinforcing bars and joints 21 is used as the bottom surface base layer, but a concrete board not containing the anti-cracking reinforcing bars, a concrete board without joints 21 and a mortar board etc. Good. In the present invention, as shown in FIG. 3 (b), the bottom base layer is not essential.

  Although the embodiments of the present invention have been described above with reference to the attached drawings, the technical scope of the present invention is not influenced by the embodiments described above. It is apparent that those skilled in the art can conceive of various changes or modifications within the scope of the technical idea described in the claims, and they are naturally also within the technical scope of the present invention. It is understood that it belongs.

1, 1a, 1b ...... Bottom board water sealing 3 ...... Stabilized soil layer 5, 109 ...... Protection soil 7, 7a, 7b ...... Water sealing sheet 9 ...... Soil water shielding layer 11 ......コ ン ク リ ー ト Concrete panel 13 ...... 地 15 15, 125 ...... Water drainage pipe 17, 111 ...... Waste 21 ............ Joint 27 ...... Water barrier layer 101 ...... Waste disposal site

Claims (6)

It is the structure of the bottom board of the waste disposal site,
Water-impervious sheet,
Protective soil installed above the water blocking sheet,
And treated soil layer that will be formed by the cement improve surface layer of the protective earth on the upper surface of the protective earth,
A water collection pipe installed on the upper surface of the stabilized soil layer;
The structure of the bottom board water shield characterized by having. A soil impermeable layer installed below the impermeable sheet,
A bottom base layer installed on the lower surface of the soil impermeable layer;
The structure according to claim 1, further comprising: The treated soil layer, the bottom panel water shield Engineering structure as claimed in claim 1 or claim 2, wherein the intensity is greater than the waste discarded waste treatment plant.   The structure of a bottom board impermeable according to any one of claims 2 to 3, wherein the bottom base layer is a concrete board, and a crack preventing reinforcing bar is embedded in the concrete board. It is the construction method of the bottom board water blocking construction of the waste disposal site,
Step a of laying a water blocking sheet,
Installing a protective soil above the water blocking sheet b,
Forming a stabilized soil layer by cement-reforming the surface layer of the protective soil c;
Installing a water collection pipe on the upper surface of the stabilized soil layer;
A method of constructing a bottom board water shield characterized by comprising. Before the step a
A process e for installing the bottom base layer on the ground;
Placing a soil impermeable layer on the upper surface of the bottom base layer;
Further equipped,
The construction method of the bottom board impermeable structure according to claim 5, wherein the impermeable sheet is laid above the soil impermeable layer in the step a.

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