JPH0733651B2 - Impermeable structure of the land - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water-impervious structure of a land for which a large number of water-impervious boards are assembled and completed.

[Prior Art] When constructing a landfill disposal site for dumping garbage, it has been a common practice to prevent wastewater and toxic substances such as drugs from underground from flowing underground and contaminating groundwater. About 1.5 mm
The impermeable sheet made of synthetic rubber was laid directly on the entire ground formed by excavation. Even when constructing an artificial pond, in order to prevent the water in the pond from leaking, the impermeable sheet made of the same synthetic rubber as above was laid directly on the ground.

This impermeable sheet is generally used for construction. As a ready-made product, the width is about 120 cm and the maximum length is about 20 m.
There is a raw sheet. However, since a wider water-impermeable sheet is required for civil engineering, a wide width sheet is made by laterally adhering a plurality of ready-made raw sheets at a rubber manufacturing plant, and the wide sheet is used for civil engineering. Here, when making a wide sheet from the original sheet, as shown in FIG. 11, the edge portions of the original sheet 50 having a width of about 120 cm are arranged so as to overlap each other, and the overlapping portion is formed by the adhesive 51. They were bonded to each other, or the downstream rubber was sandwiched in the middle to be connected by hot pressing. In this way, the wide sheets 52 are made by bonding the original sheets 50 to each other (this connecting method is hereinafter referred to as "flow joint"). This wide sheet
The maximum width of the sheet 52 is about 8 to 10 m in consideration of transportation, and the sheet 52 is shipped from the rubber manufacturing factory in the state of the wide sheet 52. When connecting the wide sheets 52 in the land, as shown in FIG. 12, the edges of the wide sheets 52 are overlapped with each other by about 20 cm, and are spread on the soil of the land, and the wide sheets 52 are Adhesives 53 are applied to the overlapping portions. After the adhesive 53 dries, the reinforcing tape 54 is adhered in the longitudinal direction with the adhesive 55 so that the edge covers the edge of the wide sheet 52 on the upper side.

As described above, by laying a water-blocking sheet over the entire ground of the land that has conventionally been required to have water-blocking such as a landfill treatment site and an artificial pond, leakage of water is prevented by the water-blocking sheet.

In addition, the outer edge of the water-blocking sheet spread over the entire landfill treatment plant or artificial pond is extended to the outside of the ground formed by excavation or the like, and is fixed to the outside. That is, as shown in FIG. 13, the top end fixing groove 56 is dug at an appropriate position on the flat ground beyond the upper end of the slope of the ground formed by excavation or the like, and the tip of the water-blocking sheet 57 is placed on the top. Put in the end fixing groove 56. After that, the tip of the water shield sheet 57 in the top end fixing groove 56 is stopped by a locking member (not shown), or the dug up soil 58 is backfilled in the top end fixing groove 56, so that the water shield sheet.
57 is fixed.

[Problems to be Solved by the Invention] As described above, in the conventional construction method of adhering overlapping portions of the wide sheet 52 with the adhesive 53 or adhering the reinforcing tape 54 with the adhesive 55 on site, groundwater is When working on soft ground that exudes, there is a drawback in that the progress of the work does not proceed as expected because the adhesive particularly dislikes water at the implementation stage. Also, in rainy weather, it is impossible to bond with an adhesive, and the water-blocking sheet leaks into the water and becomes slippery, so work must be stopped. The work had to be stopped because the water sheet was rolled up by the wind.

Further, the work of laying the wide sheet 52 on the ground is a heavy labor for holding a heavy sheet, and it is difficult to secure a worker. Further, the work of spreading the wide sheets 52 requires craftsmanship and experience, and foreign workers could not perform high quality implementation.

Further, when the water impermeable sheet is directly spread on the ground formed by excavation (there may be a non-woven fabric on the lower side), protrusions such as boulders existing on the surface of the ground may cause the reinforcing tape 54 to have a wide sheet 52. There was a problem that there was a part that floated up from the ground, a gap was created in this raised part, and water leaked out.

Moreover, when the water-impervious sheet is laid directly on the ground of the constructed land, when the protrusions such as boulders come into direct contact with the water-impermeable sheet and the ground sinks due to the weight of the discarded dust, etc. There was a problem that holes could be made in the water shield sheet by the protrusions. In addition, when applying the soil to the impermeable sheet directly laid on the ground of the constructed land, when pushing the soil with heavy machinery, protrusions such as boulders pierce the impermeable sheet or the soil is soft. If so, the water-impermeable sheet may slip or break at the water-impermeable sheet.

Furthermore, in the conventional type, a top end fixing groove for fixing the tip of the water-impervious sheet must be provided, and water accumulates in the top end fixing groove, and the water collected in the top end fixing groove fills the slope. There was a drawback that it drained.

[Object of the Invention] The present invention has been made in view of the above problems, and it is possible to easily perform the work of laying the water-blocking member even on soft ground or some bad weather, and damage to the water-blocking member occurs. The purpose of the present invention is to provide a water-impervious structure for the land that prevents sewage and harmful substances from mixing into groundwater.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a water-blocking board by attaching a water-blocking member to one surface of a polystyrene foam, and bonding a large number of the water-blocking boards with a water-expandable sealing material. While laying in the land, a step lower step is provided near the edge of the surface of the water blocking board to which the water blocking member is attached, and an anchor having a head penetrating the water blocking board is driven into the step, A water-expandable sealing material is provided on the surface of the anchor head on the side where the anchor is driven, and the water-expandable sealing material is used to block water at the anchor-driving position.

In addition, a waterproof and solid water-impervious mixed soil is spread over the surface of the ground, and a water-impervious board with a water-impervious member attached to one side of Styrofoam is placed over the water-impervious seal. A material that is adhered with a material is spread, and the water-impervious member and the water-expandable sealing material serve as a primary water-impermeable material, and the mixed soil for impermeable material serves as a secondary water-impermeable material.

Furthermore, a cubic water-blocking board with a water-blocking member attached to one side of Styrofoam is used as a lid for the ground of the land, which is bonded with a water-expandable sealing material, and the edge of the lid and the edge of the ground Are connected by a water-impervious sheet for connection through a water-expandable sealing material, and a water-impervious sheet is formed by the water-impervious sheet of the water-impervious board, the water-expandable sealing material, and the water impervious sheet for connection. The cover that forms the space is covered with the guest soil so that the impermeable space is embedded in the soil.

[Operation] In the present invention, boards in which a water-blocking sheet is bonded to styrofoam are bonded to each other using a water-expandable sealing material, and the boards are spread over the ground. At this time, since the Styrofoam is brought into close contact with the ground, the water-impervious sheet does not come into contact with the protrusions on the ground. Each board is fixed to the ground by an anchor, but by providing a water-expandable sealing material on the driving side of the head of each anchor, water can be blocked at the anchor driving point, and the anchor is driven. While adding boards, the workability on soft ground, slopes and bad weather can be improved.

Further, in the present invention, the ground is coated with the water-impervious mixed soil, and the water-impervious board is laid over the soil. by this,
A double water shield consisting of a water shield sheet and a water-expandable sealant and a water-shielding mixed soil provides a safe and reliable water shield structure.

First Embodiment Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is an overall cross-sectional view of a water-impervious structure of a land that shows an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of an essential part of FIG. 1, and FIG. 3 is an enlarged plan view of an essential part of FIG. Is.

In the present invention, a large number of water blocking boards 2 are spread over the ground 1 formed by excavation or the like. This impermeable board 2
Is a rigid block-shaped or plate-shaped styrofoam 3 with a conventionally used water-blocking sheet 4 adhered to the entire surface by a solvent-free adhesive. The styrofoam 3 is inexpensive, lightweight and has a compression resistance.
Although its size is related to the horizontal width of the water-impervious sheet 4 that can be manufactured, it is desirable that the vertical and horizontal widths are both several meters. A step portion 4 that is one step lower is formed near the outer edge of the surface of the styrofoam 3 to which the water impervious sheet 4 is attached, and the water impervious sheet 4 covers up to the step portion 5. The water blocking boards 2 adjacent to each other are adhered to each other by a water-expandable sealing material 6 made of an adhesive butyl rubber, for example. That is, the water-impervious board 2 is sequentially connected through the water-expandable sealing material 6. The water-swellable sealing material 6 expands itself when it contains water, and blocks the passage of water at the joint between the adjacent water-shielding boards 2. Impermeable board 2
As shown in FIG. 2, a joint 7 has a convex portion 7 formed on one of the impermeable boards 2 and a concave portion 8 formed on the other impermeable board 2 side to be fitted with the convex portion 7. Then, the convex portion 7 and the concave portion 8 are engaged with each other with the water expansion sealing material 6 interposed. In addition to this, as the shape of the joint portion between the water-impervious boards 2, as shown in FIG.

When laying a large number of water-impervious boards 2 on the ground 1, first, a non-woven fabric 9 is laid on the whole ground 1, and the water-expansion sheet 4 side of the water-impervious board 2 is placed on the non-woven fabric 9 so as to expand water. Adjacent water-blocking boards 2 are adhered to each other with a property sealing material 6, and a large number of water-blocking boards 2 are spread over the ground 1. here,
When the water-impervious board 2 is spread on the slope, an anchor 10 that penetrates the nonwoven fabric 9 and reaches the ground 1 is driven into an appropriate portion of the step 5. By driving this anchor 10,
The impermeable board 2 laid on the slope does not slip off from the slope. The anchor 10 is driven into the impermeable board 2 so that the head 11 of the anchor 10 is flush with the impermeable sheet 4. A water-swellable seal material 12 is provided on the bottom surface of the head 11 of the anchor 10, and the water-swellable seal material 12 provides a water blocking effect at the place where the anchor 10 is driven. Since this anchor 10 prevents the water-blocking board 2 attached to the slope from slipping off the slope, it is not necessary to hit the water-blocking board 2 laid on the bottom of the ground 1 with the anchor 10.

After the water-impervious boards 2 are joined to each other via the water-expandable sheet material 6, and after the anchor 10 has been driven in, the joint tape 13 is stepped on the joint tape 13 so as to straddle both the step portions 5 of the adjacent water-impervious boards 2. On the impermeable sheet 4 and the joint sheet 13 on which the auxiliary sheet 14 made of the same material as the impermeable sheet 4 is attached. That is, the joint tape 13 is used to attach the auxiliary sheet 14 extending over the stepped portions 5 of the adjacent water-impervious boards 2 (FIG. 3). The auxiliary sheet 14 covers and protects the water-swellable sealing material 6 for adhering the water shield board 2 and the head 11 of the anchor 10. The upper surface of the auxiliary sheet 14 and the upper surface of the waterproof sheet 4 at a position higher than the step 5 of the waterproof board 2 are set to have the same height. Water-proof caulking material 15 is attached to both sides of the auxiliary sheet 14, and the caulking material 15 blocks water on both sides of the auxiliary sheet 14 so that the water does not reach the water-expandable sealing material 6 and the anchor 10. You can

At the boundary between the bottom of the ground 1 and the slope, as shown in FIG.
A buttock board 16 is provided. This board 16 for the hips
Using L-shaped styrofoam 17, the styrofoam
A water-blocking sheet 18 is adhered to the entire inner surface of 17.
A step portion 19 is formed in the vicinity of the edge on the side to which the water blocking sheet 18 is bonded. A convex portion 20 that fits into the concave portion 8 of the water-impervious board 2 shown in FIG. 2 is formed on one end surface of the sloping board 16, and the convex portion 7 of the water-impervious board 2 is fitted to the other end surface. The concave portion 21 is formed so as to fit therewith. The buttock board 16 and the water shield board 2 are connected to each other with the water-expandable sealing material 6 interposed therebetween. When the end surface of the water-impervious board 2 has the shape shown in FIG. 4, the shape of the end surface of the buttock board 16 is also adjusted to that shape.

Since the inclination angle between the bottom surface of the ground 1 and the slope differs depending on the construction site, the slope end board 22 shown in FIG. 6 may be used. That is, the buttock board 22 is formed by connecting the styrofoam 23 and the styrofoam 24 with the elastic material 25 having a small thickness inside and a large thickness outside. This elastic material 25 can be applied even if the inclination angle between the bottom surface and the slope is different from the bending angle of the slope end board 22.

If the corners between the slopes are rounded, the flat water-impervious board 2 cannot be used.
For this reason, the flexible board shown in FIG. 7 is used for the slopes, slopes and corners. Flexible board 26
A flexible member 27 made of block-shaped or plate-shaped urethane or the like and a water-blocking sheet adhered to one surface of the flexible member 27.
It consists of 28 and. Since this flexible board 26 is deformable, prepare a large area, cut it according to the shape of the slope between the slopes, and cut the end face of the water shield board 2 and the water-expandable sealing material. Glue with 6.

When the ground formed by excavation is used as a landfill for dumping dust, a water collection structure for draining rainwater is required (not required when used as a pond). Here, FIG. 6 shows the water collecting board 29. This water collecting board 29 uses a styrofoam 31 having a U-shaped cross section and a collar portion 30 extending in parallel to both ends of the U-shape, and the styrofoam 31 has a U-shaped inner side and continues from there. A water impervious sheet 32 is adhered or welded to the entire surface of the collar portion 30, and a full mat 33 on the opposite side of the water impervious sheet 32 is adhered or welded. Water collection board 29
A step portion 34 is formed near the edge portion of the collar portion 30 on the 32 side. The water collecting board 29 has a convex portion 35 fitted to the concave portion 8 of the water blocking board 2 shown in FIG. 2 on one end surface thereof, and a convex portion 7 of the water blocking board 2 fitted to the other end surface thereof. A mating recess 36 is formed. The water collecting board 29 and the water blocking board 2 are connected to each other with the water-expandable sealing material 6 interposed therebetween. A water collecting pipe 37 is provided in the U-shaped space of the water collecting board 29, and rainwater and the like flowing down along the water blocking sheet 4 are collected by the water collecting pipe 37, and thereafter,
Guided to a designated sewage treatment plant.

When it is used as a landfill site, the water-blocking board 2 and the slab 16 or the water collection board 29 are adhered with a water-expandable sealing material and spread over the ground 1, and then block-shaped from above. Alternatively, a sheet of protective Styrofoam 38 is spread. This protective Styrofoam 38 is intended to prevent the water-blocking sheet 4 of the water-blocking board 2 from being damaged by the protruding, uncrushed, coarse dust. The protective Styrofoam 38 need only be arranged side by side, and there is no particular need for bonding.

In the water-impervious structure of the constructed land according to the present invention configured as described above, the water-impervious boards 2 are adhered to each other by the water-expandable sealing material 6 having water impermeability, and the water-impermeable sheet 4 is directed upward. Spread a large number of water-impervious water-impervious boards 2 on the ground 1,
In addition, a water-expandable sheet material is provided on the driving side of the head of each anchor to prevent water leakage at the anchor driving position.
That is, in the present invention, since the styrofoam 3 with the water-impervious sheet 4 on the upper side is brought into contact with the ground 1, even if a projection such as a boulder exists on the surface of the ground 1, the styrofoam 3 is eroded, but the water-impervious sheet 4 You can't cut in. Therefore,
When the water impermeable sheet is directly spread over the ground as in the related art, it is possible to solve the problem that projections bite into the water impermeable sheet and holes are made in the water impermeable sheet due to ground subsidence or the like.

Moreover, even when applying soil to the ground 1 of the constructed land with heavy equipment, since a large number of water-impervious boards 2 are connected and spread, the weight of the heavy equipment is distributed to the large number of water-impervious boards 2. Even if the ground is soft, it is possible to smoothly carry out the work of applying soil with heavy machinery, and projections such as boulders do not pierce the water-impervious sheet 4 and the water-impermeable sheet does not break.

Further, in the present invention, the driving location of the anchor 10 is blocked by the water-expandable sealing material 12. This facilitates the work of laying the water blocking board 2 on the slope. Further, even if the ground 1 is muddy with groundwater or the like, the work can be performed even in the rain or in strong wind, and the economic effect is great. Moreover, instead of the conventional large-area water-impervious sheet, the water-impervious board 2 mainly composed of styrene foam having a smaller area is used, so that it is less slippery when wet with water than the water-impervious sheet itself. Moreover, since the scaffold is solid, the work risk can be reduced.

The work in the present invention is to assemble the water-impervious board 2 and spread it on the ground 1, and the work is simple and does not require skill. Further, the water-impervious board 2 is much lighter than the conventional wide sheet, and it is economical because even an inexperienced worker such as a foreign worker can perform the work.

Furthermore, in the case of using the conventional water-impervious sheet, a top end fixing groove for fixing the tip of the water-impervious sheet must be provided, and the water collected in the top end fixing groove may cause the embankment slope to be washed away. However, since it is not necessary to provide the top end fixing groove in the present invention, there is no fear that the slope of the ground will be washed away.

Although the water-blocking sheet 4 made of rubber or the like is used for the water-blocking board 2, instead of the water-blocking sheet 4, a waterproof coating such as spraying or a sheet may be formed.

[Second Embodiment] Next, another embodiment of the present invention will be described with reference to FIG. On the entire surface of the ground 1 formed by excavation or the like, for example, the ground 1 having a depth of 5 meters is coated with a mixed water-impervious soil 39 having a thickness of about 50 cm. This impermeable mixed soil 39 is a cement-based solidifying agent and high-density bentonite,
The volume ratio of 60 to 150 kg: 60 to 100 kg is mixed with 1 m ³ of soil, and the mixed water-impervious soil 39 made by mixing these materials has a water-blocking effect and blocks heavy metals and radioactivity. Has an effect on. On this impermeable mixed soil 39, as in the first embodiment, the impermeable board 2, the sloping board 16, and the water collecting board 29.
Are spread with the water-expandable sealing material 6 sandwiched therebetween, and the anchor 10 is driven into the slope. When it is used as a landfill, styrofoam 38 for protection is laid over it.

The cement-based solidifying agent in the impermeable mixed soil 39 does not separate and does not change its shape even when water intervenes. The work of laying the boards 16 is much easier than the conventional one. Further, since the high-density bentonite has a restoring property as a preventive layer even if cracks occur, it is possible to secure complete water impermeability. Therefore, according to the present invention, the water-expandable sealing material 6 for water-blocking the joint surface between the water-blocking boards 2 and the mixed soil 39
Since it is a double impervious to water, more reliable impermeability can be achieved. Furthermore, since the mixed soil 39 is effective in blocking heavy metals and radioactivity, the mixed soil 39 can be used as a landfill when disposing of them.

[Third Embodiment] Next, still another embodiment of the present invention will be described with reference to FIG. In this embodiment, dust and the like are put inside the landfill site and the lid is closed. In this embodiment, as in the second embodiment, the mixed soil 39 is applied to the whole area of the ground 1 formed by excavation and the like, and the water-impervious board 2 and the buttock board are placed on the mixed soil 39.
Fill with 16. Spread the protective Styrofoam 38 on it. In this embodiment, since the lid 40 is put on immediately after dumping dust and the like, the water collecting board and the water collecting pipe shown in the first embodiment are not necessary. As the lid 40, the water-impervious board 2 to which a water-expandable sealing material is adhered is used. Then, the gap between the water blocking board 2 located at the upper end of the slope and the water blocking board 2 at the edge of the lid is closed using the water blocking sheet 41 for connection and the water-expandable sealing material 6. After that, the protective Styrofoam 38 is placed on the lid 40, and covered with the soil 42 from above.

In the invention configured as described above, the bottom surface and the slope have a two-layer or three-layer water-impervious structure, and moreover, the lid 40 is provided on the top surface to prevent water from entering the inside. It is possible to bury landfills in the soil with water and other debris contained. Moreover, since the mixed soil 39 is applied to the whole area of the ground 1, heavy metals and radioactivity can be contained in groundwater without leaking. Compared with the conventional one-layer water-impervious structure, the present invention is a two-layer or three-layer water-impervious structure, so the treatment method is perfect, so the landfill site's local can safely lease the land. It is a thing.

[Effects of the Invention] As described above, according to the water-impervious structure of the constructed land according to the present invention, a board composed of styrofoam and a water-impervious sheet is assembled via a water-expandable sealing material, and the anchor water-impervious board is attached to the board. A water-expandable sealing material is provided at the driving position. As a result, in the present invention, the water-impervious sheet is not damaged by projections such as boulders, and furthermore, the anchor is driven into the board to prevent slipping of the board on the slope, improving workability, and muddying. Work can be performed even in the ground or in rainy weather, the board itself is less slippery and the risk of work can be reduced, and there is no risk of breakage of the waterproof sheet due to heavy equipment when applying soil to the ground, Since there is no need for the top fixing groove that was required in the past, there is no risk of the embankment slope being washed away.

In addition, if the soil is mixed with water-impervious soil and a water-impervious board is laid over it, a double impermeable structure will be created and safety will increase. Moreover, if the impermeable mixed soil is composed of a cement-based solidifying agent and high-density bentonite, it is possible to prevent heavy metals and radioactive substances from mixing into groundwater.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view of a water-impervious structure of a land that shows an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of an essential part of FIG. 1, and FIG. 3 is an enlarged plan view of an essential part of FIG. , FIG. 4 is a cross-sectional view showing another structure of the end face of the water-impervious board, FIG. 5 is a cross-sectional view showing one example of the buttock board, and FIG. 6 is a cross-sectional view showing another example of the buttock board. , FIG. 7 is a perspective view showing an example of a flexible board,
FIG. 8 is a cross-sectional view of a water-impervious board for collecting water, and FIG. 9 is an overall cross-sectional view of a water-impervious structure of a land showing another embodiment of the present invention.
Figure is a partial enlarged cross-sectional view of the water-impervious structure of the constructed land showing another embodiment of the present invention, Figure 11 is a cross-sectional view of the flow joint portion of the conventional water-impervious sheet, Figure 12 is the sheet of Figure 11. FIG. 13 is a cross-sectional view showing a state in which a reinforcing tape is attached to the flow joint portion, and FIG. 13 is a cross-sectional view showing a state in which a waterproof sheet is attached by a conventional top end fixing work. 1 ... Ground, 2 ... Water-blocking board, 3 ... Styrofoam, 4 ... Water-blocking sheet, 5 ... Step, 6 ... Water-expandable sealing material, 7 ... Projection, 8 ... Recess, 10 …… Anchor, 11
...... Head, 12 …… Water-expandable sealing material, 13 …… Joint tape, 14 …… Auxiliary sheet, 15 …… Caulking material, 16…
… Board for buttocks, 22 …… Board for buttocks, 25 …… Elastic material,
38: Styrofoam for protection, 39: Mixed soil for water blocking, 40
...... Lid, 41 ...... Connection water barrier sheet, 42 ...... Customer soil.

Claims (14)

[Claims] 1. A water-blocking board is obtained by attaching a water-blocking member to one side of styrofoam, and a large number of the water-blocking boards are adhered to each other by a water-expandable sealing material and spread over the land, and the water-blocking board is water-blocked. A lower step is provided near the edge of the surface on which the member is attached, and an anchor having a head that penetrates the water-impervious board is driven into that step, and the anchor head has a water-swelling property on the advancing side of the head. A water-impervious structure in a constructed area, which is equipped with a sealant, and the water-expandable sealant is used to shield the anchor driving point. 2. The water-impervious structure of a terrestrial land according to claim 1, wherein protective polystyrene foam is laid on the water-impervious board. 3. The water-impervious structure of a terrestrial land according to claim 1, wherein engaging projections and depressions are formed at joints between the water-impervious board and the water-impervious board. 4. A reinforcing tape is fixed to the surface of the step by adjoining the step of adjacent water-impervious boards with a joint tape, and the joint between the water-impervious boards and the location of anchors are covered with the reinforcing tape. The water-impervious structure of the constructed land according to claim 1. 5. The reinforcing tape is covered with a caulking material on both sides of the reinforcing tape and a water impervious sheet in the vicinity of the edge, and the caulking material and the water impervious sheet are used for water impermeability.
Impermeable structure of the listed land. 6. In a board for fascia having a curved portion in the middle of the length of the water-impervious board, two styrofoams and an inner width at a position where the styrofoam is curved at a length between the two styrofoams. 2. The water-impervious structure for a constructed land according to claim 1, further comprising an elastic material having a small thickness and a large outer thickness. 7. A waterproof and solid water-impervious mixed soil is laid on the surface of the ground of the constructed land, and a water-impervious board having a water-impervious member attached to one side of styrofoam is placed on the water-impervious mixed soil. Spread the one bonded with an expansive sealing material, the water-impervious member and the water-expandable sealing material as the primary impermeable, and the mixed soil for impermeable to the secondary impermeable, characterized by Impermeable structure. 8. The water-impervious structure of a landfill according to claim 7, wherein the water-impervious mixed soil comprises a cement-based solidifying agent, high-density bentonite, and soil. 9. The water-impervious structure of a land for construction according to claim 7, wherein protective polystyrene foam is laid on the water-impervious board. 10. The engaging projections and depressions are formed at the joints between the water shield board and the water shield board.
Impermeable structure of the listed land. 11. A step portion having a lower step is provided near the edge of the surface of the impermeable board to which the impermeable member is attached, and an anchor having a head penetrating the impermeable board is driven into the step portion, and the anchor The water-impervious structure of a landfill according to claim 7, wherein a water-expandable seal material is provided on a surface of the head on which the head is driven, and the water-expandable seal material is used for impervious water at the anchor driving position. 12. A reinforcing tape is fixed to a surface of the stepped portion of adjacent water-impervious boards with a joint tape, and the reinforcing tape covers a joint portion between the water-impervious boards and an anchor driving portion. 12. The water-impervious structure of a constructed land according to claim 11. 13. A cubic water-blocking board having a water-blocking member attached to one side of styrofoam, which is adhered with a water-expandable sealing material, is used as a lid of the ground of the land, and is spread over the edge of the lid and the ground. The edge portion is connected with a water-impervious sheet for connection through a water-expandable seal material, and a water-impervious sheet is formed by the water-impervious sheet of the water-impervious board, the water-expandable seal material, and the water-impervious sheet for connection. The water-impervious structure of the constructed land, which is characterized in that the water-impervious space is buried in the soil by covering the cover with the water-impervious space with a soil cover. 14. The land according to claim 13, wherein protective foam polystyrene is laid on a lid having a water-impervious space, and then the water-impervious space is buried in the soil by covering the soil. Water barrier structure.