JP2000273870A - Ground stabilizing construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground stabilizing construction method capable of reducing ground subsidence after construction to such extent that there is no problem in practical use, ensuring predetermined compression strength, and facilitating handling of foaming styrol crushed pieces when back filling, backing, and banking are done using foaming styrol crushed pieces. SOLUTION: Bag bodies 2,... in which foaming styrol crushed pieces 2F,... are filled are piled up and filled up to an intermediate part of a predetermined backing height for a back-filling or backing section whose surroundings are restrained substantially to form a first layer 3 composed of the crushed piece containing bag bodies 2,..., preferably, a water permeating sheet 5A is spread on its top face, and furthermore, earth and sand 5B are spread uniformly on its top face to form a covered layer 4. Then, a load is applied from above by an excavation heavy machine such as a shovel and a compacting heavy machine such as a roller from above the covered layer 4. Since foaming styrol crushed pieces 2F,... are sealed and restrained in the bag bodies 2,..., respectively, and a side face and a bottom face of a bag body layer 3 are surrounded and restrained by a retaining wall 1 and an original ground 9, they are compressed to reduce a porosity, and they are plastically compressed and deformed to increase compression strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stabilizing a ground including lightweight backfill, lightweight backfill and lightweight embankment using styrene foam as an artificial lightweight material.

[0002]

2. Description of the Related Art As a method for stabilizing the ground including such lightweight backfilling, lightweight backfilling and lightweight embankment, a styrofoam block is used as an embankment material and backing material, and road and land development, backfilling, back lining of structures. EPS (Expand
ed poly-Styrol) method is widely used.

[0003] As is well known, the EPS method is shown in Figs.
As shown in (C), styrofoam blocks 30, 30... (2m × 1m × 0.1m and 2m × 1m × 0.5m) of specified dimensions are densely arrayed and used. Thus, a predetermined compressive strength is ensured, and compression deformation after operation is prevented.

[0004] Styrofoam is mainly composed of polystyrene obtained by polymerization of styrene monomer produced by petroleum refining and a foaming material added thereto.
It has physical and mechanical properties such as super light weight, excellent compression resistance, weather resistance, and chemical resistance, and can be suitably used as lightweight materials for civil engineering.
Since it has construction advantages such as not requiring large heavy equipment, it can be said to be a very suitable ground soil substitute material for the ground stabilization method for reducing the load and the earth pressure.

However, in the EPS method, styrene foam blocks of a specified size are densely arranged and laminated in order to secure a predetermined compressive strength and prevent compression deformation after the service, so that the earth pressure and the load on the load can be reduced. Although it has great advantages such as the suppression of settlement of structures on soft ground and the reduction of the size of adjacent structures, the cost of backfilling and embankment alone is more expensive than normal landfill There's a problem.

On the other hand, Styrofoam has excellent heat insulating properties, cushioning properties, and easy moldability in addition to ultra-light weight, so that it is used today in food storage boxes such as fresh seafood and electric equipment. Although it is an indispensable material in various fields, such as packaging and events at various event venues, it is generally discarded as it is once used, and it is rarely collected and reused. And the amount of waste is enormous. In addition, rejected products are generated when manufacturing a styrofoam food storage box or packing material, and these are directly discarded. Moreover, since this styrofoam is a synthetic resin, a large amount of smoke is generated when it is incinerated, which causes pollution, so that incineration often requires special treatment costs.

Therefore, one of the applicants of the present application has filed Japanese Patent Application No.
In Japanese Patent Application No. 344322 and Japanese Patent Application No. 7-344323, an invention was proposed in which crushed styrofoam of a predetermined size was used as a lightweight aggregate for civil engineering. In general, Styrofoam is vulnerable to point compression, but exhibits a large resistance to a compressive load that is planar over the entire or constant area. The reason that the conventional EPS method densely stacks and stacks large block-shaped styrofoam is for this reason.However, if crushed styrofoam of gravels or boulders were used as lightweight backfill material, There is a portion where the styrene pieces come into contact with each other on the surface and a portion where the styrene pieces come into contact with each other at points, and the compression strength is not so large. Further, since the porosity is as high as about 50%, there is a problem that the settlement due to the overload is large. Of course, there is no problem as long as it is used as a mere backfill replacement material at a place where a large overload does not occur, but when used at a place where a predetermined load is loaded, the compressive strength that can withstand it It is required to secure the landfill and to improve the settlement after landfill or embankment to a level that does not hinder practical use.

In view of such a demand, the present applicant has disclosed in Japanese Patent Application No. Hei 8-231576 (Japanese Patent Application Laid-Open No. 10-77631) that a styrene foam crushed piece is used as a substitute material, and that A ground stabilization method is proposed in which the crushed pieces placed in the backfill or backfilling area or the embankment area are spread or spread, and the arranged crushed pieces are compressed and deformed, and the compressed deformed material is backfilled (hereinafter, referred to as a backfilling method). , Referred to as a precedent).

[0009]

However, there is a problem that the crushed pieces of styrofoam in a fragmented state are difficult to handle. For example, if the wind blows to some extent during construction, the crushed pieces may be blown or blown by the wind when throwing or leveling Styrofoam crushed pieces. I can't work.

Accordingly, a main object of the present invention is to perform landfilling, backfilling and embankment using crushed styrofoam pieces to reduce ground subsidence after construction to a practically acceptable level, An object of the present invention is to provide a ground stabilization method that can ensure the compressive strength and facilitates the handling of styrene foam crushed pieces.

[0011]

Means for Solving the Problems Of the present invention which has solved the above-mentioned problems, the invention according to claim 1 relates to a styrofoam in a ground stabilization method for backfilling, backfilling or embankment using a styrofoam material. The bag body in which the crushed pieces are sealed is placed on the backfill site, the backfilling site, or the embankment site, and pressure is applied to the upper surface of the placed bag body, and the styrene foam crushed pieces are sealed in the bag body. The ground stabilization method is characterized by compressing and deforming in a compressed state, and using the compressed deformed material as a backfill for a backfill site, a backfill for a backfill site, or an embankment for an embankment site.

According to a second aspect of the present invention, in a ground stabilization method of performing backfilling, backfilling, or embankment using a styrofoam material, a bag body in which compressed styrofoam crushed pieces are sealed is backfilled. Backfill material for the site,
This is a ground stabilization method characterized by performing backfilling, backfilling or embankment as a backfill material for a backfill site or an embankment material for an embankment site.

According to a third aspect of the present invention, when a structure is constructed on the backfilled, backfilled, or embanked ground, the compressive deformation of the lightweight bag is reduced by the structural design load. The ground stabilization method according to claim 1, wherein the above-mentioned load is applied.

According to a fourth aspect of the present invention, the hardening material liquid is injected and filled into at least the gaps between the styrofoam fragments in the bag in which the styrofoam fragments are sealed. The ground stabilization method according to item 1.

According to a fifth aspect of the present invention, the injection of the hardening material liquid into the gaps between the styrofoam fragments is performed through an injection pipe facing a discharge port in a bag in which the styrofoam fragments are sealed. 4 is a ground stabilization method.

According to a sixth aspect of the present invention, there is provided the ground according to any one of the first to fifth aspects, wherein a hardening material liquid is injected and filled into a space between the bags outside the arranged bags. It is a stabilization method.

According to a seventh aspect of the present invention, the hardening material liquid is injected into the space between the bags outside the arranged bags through an injection pipe having a discharge port facing the outside of the arranged bags. A ground stabilization method according to claim 6 to be performed.

The invention according to claim 8 is the ground stabilization method according to any one of claims 4 to 7, wherein the compression deformation is not performed when the hardening material liquid is injected.

According to a ninth aspect of the present invention, as the bag,
Claims using a bag formed of one or more materials selected from the group consisting of a liquid impermeable sheet, a liquid permeable sheet, a stretchable sheet, a net, and a geotextile including a geogrid and a geonet. Item 1
8. The method for stabilizing the ground according to any one of 8.

[0020] The invention according to claim 10 is the ground stabilization method according to any one of claims 1 to 9, wherein crushed pieces of styrofoam are used as the styrene foam crushed pieces.

The invention according to claim 11 is the ground stabilization method according to any one of claims 1 to 10, wherein another crushed piece of foamed resin is used together with or instead of the crushed styrofoam.

<Operation> The main structure of the present invention resides in that crushed styrene foam pieces are sealed in a bag. With such a configuration, unlike the case where crushed pieces of styrofoam are handled in pieces, a large number of crushed pieces are enclosed in a bag.
Since it can be handled as one block-like object, construction is also facilitated.

Further, there is an advantage of using the styrene foam crushed pieces. That is, it is possible to recycle styrofoam waste, which has been conventionally treated as industrial waste, and the material cost is reduced.

In the case of a large block which has been used in the past, in order to fill the space without any gap according to the shape of the location, the styrofoam block is cut or the like.
Styrofoam blocks had to be stacked and arranged.However, the bag body containing the styrofoam fragments can be easily deformed into any shape because each crushed piece is in a state where it can move freely. Also excellent.

On the other hand, while having these advantages, simply placing the styrofoam crushed pieces in a bag at a predetermined position simply results in a point-to-point contact between adjacent crushed pieces having a large gap between the styrofoam crushed pieces. For this reason, land subsidence is so great that compressive strength cannot be secured. However, in the present invention, as in the previous example, the bag body enclosing the styrofoam crushed pieces is subjected to compressive deformation by applying pressure by load loading, rolling pressure, etc., or by injecting and filling a hardening material liquid inside and outside the bag body. This solves the problem. The compression deformation and the injection and filling of the hardening material liquid can be performed before or after the bag body is arranged.

On the other hand, with regard to the structure for injecting the hardening material liquid, particularly when injected into the bag, each of the crushed pieces is sealed and restrained in the bag although its specific gravity is light. Has the advantage of not having a separate layer configuration. In addition, if the hardening material liquid is injected into the outside of the bag, particularly after the injection into the bag body, the bag body becomes heavier due to the hardening material liquid, so that the crushed piece enclosing bag and the injected hardening material liquid have a layered structure. Nor. As a result, the styrofoam crushed pieces and the hardened material having good adhesiveness form a rib structure, and it is possible to construct a back-filled material or the like having low land subsidence and high compressive strength.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. <Example of Backfilling> FIG. 1 shows a vertical cross section of a backfilling portion that has been backfilled according to the method of the present invention. The backfill site of this example is a concave space whose periphery is substantially constrained by the earth pressure-resistant structure such as the retaining wall 1 and the original ground 9. To perform backfill for such a site, for example, First, the bags 2,... Enclosing the polystyrene crushed pieces 2F,... Are stacked and filled up to the middle of a predetermined backfill height to form a first layer 3 composed of the crushed piece enclosing bags 2,. Preferably, subsequently, a water permeable sheet 5A is laid on the upper surface, and further, earth and sand 5B or the like is laid on the upper surface to form a coating layer 4. After that, this coating layer 4
The overhead load is applied from above by a heavy excavator such as a shovel or a heavy rolling machine such as a roller. Since the styrofoam fragments 2F,... Are respectively enclosed and restrained in the bags 2,..., And the bag layer 3 is surrounded and restrained by the side walls and the bottom surface by the retaining wall 1 and the original ground 9, the styrofoam fragments 2F,. Are compressed to reduce the porosity, and plastically compressively deform to increase the compressive strength. If the upper surface of the bag body layer 3 is covered and restricted by the covering layer 4 as in the illustrated example, there is an advantage that the bag body layer 3 can be easily compressed and deformed.

Next, on the coating layer 4, bags 2,... Each further enclosing styrofoam fragments 2F,. The second layers 6 are formed. Thereafter, the earth and sand 7 serving as the surface soil is developed by a heavy excavator such as a shovel or a compacting heavy machine such as a roller, and backfilled to a predetermined backfilling height while being compacted. The second layer 6 is compressed and deformed. A compressive load can be applied by a weight lifted by a crane instead of the excavating heavy machine or the compacting heavy machine.

In the present embodiment, the construction is divided into two parts, since the retaining wall 1 is high, and divided into a first layer 3 and a second layer 6 composed of crushed piece enclosing bags 2,. Although compression deformation is performed, when the height of the retaining wall 1 is low, one construction step can be performed.

When a structure such as a building is to be constructed on the backed ground, an embankment 8 corresponding to this load is formed in order to apply a precedent load equal to or greater than the structure design load, and consolidation is advanced. You can also. Consolidation for ordinary clay layers is to perform forced drainage by increasing pore water pressure by compressive load, and it takes several months to several years. On the other hand, when the target is styrene foam crushed fragment layers 3, 6, Are aimed at the reduction of the porosity, the plastic compression deformation of the styrofoam crushed pieces 2F,... Aging strain, etc., and a loading period of about one week is sufficient.

Here, the styrofoam crushed pieces 2F and the bag body 2 used in the above and below examples will be described. Needless to say, Styrofoam crushed pieces 2F are mainly made of Styrofoam waste, but those having a size exceeding 500 mm in length, width, or length must be enclosed in the bag 2 for operability. Due to the above disadvantages and an increased porosity, those having a diameter of 500 mm or less, preferably 350 mm or less, are suitably used. On the other hand, fine-grained pieces having a length, width, or length of less than 5 mm require extra time and effort such as crushing, and can also contribute to strength development etc. because they only fit within large styrene foam crushed pieces. Not so effective. Further, when the hardening material liquid described later is injected, it becomes a factor that hinders the injection. Therefore, it is preferable that the crushed pieces have a minimum size of 5 mm or more, preferably 10 mm or more.

In order to obtain the crushed pieces according to the present invention from the styrofoam waste material, the crushed pieces can be crushed by applying a blow or the like. However, if the crushed pieces are cut through a cutting machine using a nichrome wire for cutting, the crushed pieces can be obtained. Many pieces having a smooth surface can be obtained, and many pieces having an appropriate size can be obtained without generating crushed debris. In the present invention, other crushed foam resin pieces may be used together with or instead of the styrofoam crushed pieces 2F.

In the present invention, the styrofoam crushed pieces 2F are sealed in the bag body 2. The crushed pieces 2F can be filled in the bag 2 at the factory together with the crushing of the polystyrene foam, but may also be performed at the construction site. Examples of the bag body 2 include a liquid-impermeable sheet, particularly a sheet that is liquid-impermeable with respect to a curing material liquid described below, a liquid-permeable sheet, particularly a sheet that is liquid-permeable with respect to a curing material liquid described later, a rubber sheet, and the like. Formed from one or two or more flexible materials selected from the group consisting of a stretchable and deformable sheet, a net having a smaller hole diameter than crushed pieces, and a geotextile including a geogrid and a geonet. Can be used. The shape and size of the bag 2 can be determined as appropriate. For example, the shape and size of the styrofoam block in the above-mentioned EPS method, for example, a rectangular parallelepiped shape of 2 m × 1 m × 0.5 m can be used. Bags 2 ', 2' having different shapes and sizes can also be used.

As described above, in the present invention, the above-mentioned Japanese Patent Application No.
The coating layer 4 can be formed in the same manner as described in JP-A-231576. The covering layer 4 may be a water-permeable sheet alone, earth and sand alone, or a geotextile such as a net, a geogrid or a geonet. In any case, a material capable of covering the upper surface of the bag body layer 3 is used.

<Example of Embankment> Next, a case of constructing an embankment according to the method of the present invention will be described. As shown in FIG. 2, the vegetation sandbags 10, 10... Are first stacked on the side method surface portion at a predetermined height, and in the example shown in FIG. Are stacked and filled to form a first layer 12 composed of the crushed piece enclosing bags 2,..., And earth and sand 11 are spread over the upper surface thereof to form a coating layer 13. Rolling is performed from above the coating layer 13 by a rolling machine such as a roller to compact the earth and sand 11 and compressively deform the crushed piece enclosing bag layer 12.

Next, the vegetation sandbags 10, 1 are again placed on the side method surface.
Are stacked on the coating layer 13 to form a second bag comprising the crushed piece enclosing bag bodies 2,. The layer 14 is formed, and the earth and sand 11 are spread on the layer 14 and pressed from above. In this case, the crushed piece enclosing bag body layer 12,
It is preferable that the stacked thickness of 14 is about 30 to 100 cm, and the thickness of the coating layer 13 is about 10 to 30 cm. In addition,
The longitudinal direction of the embankment is considered to be a semi-infinite region, and no structural lateral constraint is applied.

As the covering layer 13, a water-permeable sheet or a net can be laid on the lower surface of the earth and sand 11, and a geotextile such as a geogrid or a geonet can be used alone or in combination with earth and sand. it can.

On the other hand, an example will be described below in which the hardening material liquid is injected into the bag body or outside the bag body without applying any overload or rolling. However, in the present invention, even in the case where the crushed piece enclosing bag is compressed and deformed by the application of the overload or the rolling force as in the above example, the hardening material liquid can be injected into and out of the bag. <Example of embankment injecting hardening material liquid> In the example of embankment shown in FIG.
In a state where 0, 10,... Are stacked up to three levels and the sides are constrained, bags 2, in which styrene foam crushed pieces 2F,.
A first layer 12 is formed. Thereafter, preferably, a geogrid 17 is laid on top of the first layer 12
Are fixed, and both sides thereof are fixed to restrain the crushed piece enclosing bags 2,... From moving. Next, in this restrained state, at the bottom side position of the first layer 12,
The hardening material liquid 16 is slowly injected through the injection pipe 15 facing the discharge port 15H into the inter-bag space S1 on the outside of the bag body 2 to solidify the first layer 12 region.

Next, the vegetation sandbags 10, 10...
Are piled up and laterally constrained, the bags 2,... Enclosing the styrofoam crushed pieces 2F,... Are stacked to form a second layer 14 composed of these crushed piece enclosing bags 2,. 15 is lifted upward, and the hardening material liquid 16 is slowly injected by facing the discharge port 15H to the inter-bag space S1 outside the bag body 2 at the bottom side position of the second layer 14, and the second layer 14 Allow the area to solidify. After that, the top layer is covered with the covering soil 20 and compacted by rolling.

Regarding the injection of the hardening material liquid 16, in the above-described example, the discharge port 15H of the injection pipe 15 is located outside the bags 2,. , S2. However, when the bag body 2 is formed of a sheet, a net, or the like that shows liquid permeability with respect to the hardening material liquid 16, the injected hardening material liquid 16 passes through the bag wall as shown in FIG. Is also injected and filled into the space S2 between the styrofoam fragments.
Furthermore, when the styrofoam fragments themselves have liquid permeability, they penetrate into the styrofoam.

Conversely, if the bag 2 is formed of a material that is impermeable to the hardener liquid 16, the injected hardener liquid 16 does not pass through the bag wall as shown in FIG. The hardener liquid 16 is filled with the voids S between the styrofoam fragments in the bag 2.
3 is not filled. However, in the following manner, the curing agent liquid 16 can be injected and filled into the space S3 between the styrofoam fragments in the bag body 2. That is, for example, when stacking the bags 2,.
.. Or (the bag may be a pre-placed bag), for example, as shown in FIG.
The hardening material liquid is injected and filled into the bag 2 through the injection pipe 15 'in a state where the discharge port 15H' faces the inside of the bag 2 by piercing 5 '. When the curing agent liquid is injected into each of the bags after the arrangement, the injection may be performed every time the bags 2, 2. Thus, the bag body 2 is
Even when the material 6 is made of a material that is impermeable to liquid, the hardener liquid 16 can be injected and filled into the space S2 between the styrofoam crushed pieces in the bag body 2. This direct injection method can of course also be applied when the bag 2 is formed of a liquid-permeable material. In addition to the direct injection into the bag body, the injection into the bag outer space S1 can be performed as described above.

As the hardening material liquid of the present invention, for example, a mixture of soil and water or muddy water to which a fluidizing material such as bentonite is added and a solidifying material, mortar, foam cement paste, coal ash and the like are used. Appropriate materials such as those obtained by mixing with a solidifying material and those obtained by adding a foaming agent thereto can be used.

<Example of Retaining Wall Type Embankment Injecting Hardening Material Liquid> FIG.
In the case of the retaining wall type embankment shown in
The basic construction procedure is the same except that the point of division is different from that of the geogrid 17 and the point at which the ground end of the geogrid 17 is fixed by the anchor 18. Although the structure is different in that the vertical wall is the retaining wall 20, the backfill procedure of the retaining wall type embankment is shown in FIG.
(A) to (D) are shown. In the example of FIG. 8, the embankment 19 is formed on the surface layer to give a preload.

<Others> In the present invention, the bag body in which the compressed and deformed styrofoam fragments are enclosed may be used as a backfill material for the backfill site, a backfill material for the backfill site, or an embankment material for the embankment site. Yes (Claim 2
Described invention). In this case, the bag body in which the compressed and deformed styrofoam fragments are sealed can be manufactured mainly by two methods. That is, the first method is a method of compressively deforming the styrofoam fragments prior to enclosing them in the bag and enclosing them in the bag, and the second method is enclosing the styrofoam fragments in the bag. This is a method of compressing and deforming the compressed material in advance prior to the placement on the construction target site.

[0045]

As described above, according to the present invention, even when crushed styrofoam is used, backfilling, backfilling and embankment are performed using crushed styrofoam while facilitating the handling thereof. The land subsidence can be reduced to a level where there is no practical problem, and a predetermined compressive strength can be secured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view when backfilling is performed according to the method of the present invention.

FIG. 2 is a longitudinal sectional view when a lightweight embankment is constructed according to the present invention.

FIG. 3 is a longitudinal sectional view when a lightweight embankment is constructed according to the present invention.

FIG. 4 is an enlarged longitudinal sectional view of a main part showing a first hardening material liquid injection state.

FIG. 5 is an enlarged vertical sectional view of a main part showing a second hardening material liquid injection state.

FIG. 6 is a longitudinal sectional view of a main part showing a mode in which a curing agent liquid is directly injected into a bag body.

FIG. 7 is a longitudinal sectional view when a retaining wall type embankment is constructed according to the present invention.

FIG. 8 is a backfilling procedure diagram of a retaining wall type embankment.

FIG. 9 is an explanatory view of a conventional EPS method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Retaining wall, 2 ... Bag body, 2H ... Styrofoam fragment, 3
12: first styrofoam layer 4, 13: coating layer,
5A: water-permeable sheet, 5B ・ 7 ・ 11 ・ ・ ・ earth and sand, 6.14
... second polystyrene foam layer, 8 ... embankment, 10 ... vegetation sandbag, 15 ... injection pipe, 15 '... sharp tip injection pipe, 17 ... geogrid, 18 ... anchor

Claims (11)

[Claims] In a ground stabilization method for backfilling, backfilling or embankment using a styrofoam material, a bag in which crushed styrofoam is sealed is applied to a backfill site, a backfill site or an embankment site. While applying pressure to the upper surface of the placed bag body, compressively deforming the styrofoam crushed pieces in a state of being sealed in the bag body. A ground stabilization method characterized by being a backfill for an embedding part or an embankment for an embankment part. 2. A ground stabilization method for backfilling, backfilling or embankment using a styrofoam material, comprising: A ground stabilization method characterized by performing backfilling, backfilling or embankment as a backfill material for a backfill portion or an embankment material for an embankment portion. 3. When constructing a structure on the backfilled, backfilled or embanked ground that has been backfilled, compressive deformation of the lightweight bag is applied by applying a load greater than the design load of the structure. The ground stabilization method according to claim 1 or 2, wherein the method is performed. 4. The ground stabilization according to claim 1, wherein a hardening material liquid is injected and filled into at least voids between the styrofoam fragments in the bag in which the styrofoam fragments are sealed. Chemical method. 5. The ground stabilization method according to claim 4, wherein the injection of the hardening material liquid into the gaps between the styrene foam crushed pieces is performed through an injection pipe facing a discharge port in a bag body in which the styrofoam crushed pieces are sealed. Law. 6. A hardening material liquid is injected and filled into the space between the bags outside the arranged bags.
The ground stabilization method according to any one of claims 5 to 10. 7. The method according to claim 6, wherein the injection of the hardening material liquid into the space between the bags on the outside of the arranged bags is performed through an injection pipe having a discharge port facing the outside of the arranged bags. Ground stabilization method. 8. The ground stabilization method according to claim 4, wherein the compression deformation is not performed when the hardening material liquid is injected. 9. The bag according to claim 1, wherein the bag is a liquid-impermeable sheet, a liquid-permeable sheet, a stretchable sheet, a net, and one or more selected from the group consisting of geotextiles including geogrids and geonets. The ground stabilization method according to any one of claims 1 to 8, wherein a bag body made of a material is used. 10. A styrofoam crushed piece obtained by crushing styrofoam waste material.
The ground stabilization method according to any one of the above items. 11. The ground stabilization method according to claim 1, wherein another crushed foam resin piece is used together with or instead of the styrene foam crushed piece.