JP2020197018A - Improved base structure, and construction method of improved base - Google Patents

Abstract

To provide an improved base structure and a construction method of the improved base structure having high a restraining action implemented by a gripping sheet with a simple method and having little deflection deformation amount.SOLUTION: An improved base structure comprises: a gripping sheet laid on a ground 10; a plurality of weight pillows 40 mounted at an interval on the gripping sheet; a support layer body 50 compacted to be formed inside the weight pillow 40; and a loading layer 60 formed on an upper face of the gripping sheet. A level difference is provided between layer thickness of the support layer body 50 and a height of the support layer body 50, so as to utilize loading weight of the loading layer 60 to introduce a tensile force to the gripping sheet, and thereby, to rigidly restrain the weight pillow 40 and the support layer body 50 using the tensile force introduced over the whole periphery of the gripping sheet.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface treatment technique for soft ground, and more particularly to a structure of an improved base and a method of constructing the improved base, which can be applied as support for heavy structures on soft ground and trafficability of construction machinery and the like.

As a method of supporting various heavy structures (concrete retaining wall, culvert such as box culvert, reinforced soil wall, etc.) on soft ground, a mattress method using an improved foundation is known (Patent Documents 1 and 2). ).
This mattress method forms an improved foundation by wrapping it with a large holding sheet so that the soil material formed in a mat shape on soft ground can be restrained, and uses the rigidity and elasticity of the improved foundation to be above the improved foundation. It is a construction method that evenly supports the loading load of the heavy-duty structure constructed in.
The improved base is made by sprinkling the soil material in layers in the center of a large holding sheet laid on soft ground, rolling the sprinkled soil material, and then tensioning it to wrap the soil material. A mat-like improved base is manufactured by fixing the ends.
When a heavy-duty structure is constructed on the improved base manufactured in this way, a tensile force is generated on the holding sheet when the improved base is flexed and deformed due to the load of the heavy structure, and the tensile force of the holding sheet with respect to the soil material. Acts as a binding force.

In addition, from the combination of a honeycomb-shaped three-dimensional reinforcing material in which a large number of cells capable of accommodating crushed stone and other filling materials are defined, and a geotextile sealing sheet that individually closes the upper and lower opening surfaces of the three-dimensional reinforcing material. An improved base is also known (Patent Document 3).
In this type of improved base, rigidity is ensured by restraining the displacement of the filling material in each cell by the restraining action of the honeycomb-shaped three-dimensional reinforcing material. Since the upper and lower sealing sheets are separated from each other, the tensile resistance at the time of bending deformation of the improved base is very small.

Japanese Unexamined Patent Publication No. 8-209670 Japanese Unexamined Patent Publication No. 11-181750 Japanese Unexamined Patent Publication No. 2010-255247

The conventional mattress method has the following problems.
<1> With the conventional mattress method, it is difficult to give a sufficient tensile force to the entire holding sheet during the production of the improved base. This is because a part of the holding sheet is liable to loosen during construction, a sufficient tensile force cannot be introduced into the holding sheet, and it is difficult to compact both ends of the mattress.
Therefore, even if the improved foundation bends and deforms, a sufficient restraining effect of the soil material cannot be obtained, and there is a concern about uneven settlement.
<2> If the binding force of the holding sheet is insufficient, there will be a problem that the soil material will loosen or fluidize during an earthquake.
<3> The improved base using the honeycomb-shaped three-dimensional reinforcing material is at least the process of bringing the three-dimensional reinforcing material to the site, the process of deploying the three-dimensional reinforcing material, the process of filling the filling material into each cell, and the process of filling the filling material. Many work processes such as a compaction process are required, and it takes a lot of time and cost to construct the improved base.

The present invention has been made in view of the above points, and an object of the present invention is a structure of an improved base having a high restraining action by a holding sheet and a small amount of deflection deformation by a simple method, and a construction method thereof. Is to provide.
Further, another object of the present invention is to provide a structure of an improved base having a high bearing capacity and a construction method thereof by effectively suppressing loosening and fluidization of soil materials even when a repeated load such as an earthquake acts. There is.

The present invention has a mat-like improved base structure, which comprises a holding sheet spread and laid on the ground, and a plurality of weight pillows placed on the holding sheet at intervals. It is composed of a support layer main body formed by compacting the inside of the plurality of weight pillows and a loading layer formed on the upper surface of the holding sheet, and the layer thickness of the support layer main body is greater than the height of the weight pillows. With a small dimensional relationship, the holding sheet is wrapped around a plurality of weight pillows and support layers, and the upper surface of the holding sheet is embedded and fixed between the support layer main body and the loading layer to be fixed to the above-mentioned loading layer. The weight pillow and the support layer body are restrained by the tensile force of the holding sheet introduced by utilizing the load.
In another embodiment of the present invention, the support layer body is composed of granules sprinkled and compacted on the bottom surface of a holding sheet exposed inside a plurality of weight pillows.
In another embodiment of the present invention, the support layer body is arranged on the bottom surface of a holding sheet exposed inside a plurality of weight pillows, and a three-dimensional reinforcing material having a plurality of cells is filled and compacted in the cells. It is composed of the granules.
In another embodiment of the present invention, the weight pillow is composed of a single sandbag or a plurality of stacked sandbags.
In another embodiment of the present invention, the side surface of the holding sheet wrapped around and restrained by the weight pillow has a curved surface.
The present invention is a method for constructing a mat-shaped improved base, in which a plurality of weight pillows are placed at intervals on a holding sheet laid on the ground to position the bottom surface of the holding sheet. A support layer body having a layer thickness smaller than the height of the weight pillow is formed on the bottom surface of the holding sheet exposed inside the weight pillow, and the upper surface of the holding sheet wrapped around the plurality of weight pillows and the support layer body. A loading layer is formed on the surface.
In another embodiment of the present invention, granules are sprinkled on the bottom surface of the holding sheet positioned by the plurality of weight pillows and compacted to form a support layer main body.
In another embodiment of the present invention, it is supported by a three-dimensional reinforcing material having a plurality of cells arranged on the bottom surface of a holding sheet positioned by the plurality of weight pillows, and granules filled and compacted in the cells. Form a layer body.
In another embodiment of the present invention, the weight pillow is composed of a single sandbag or a plurality of sandbags.
In another embodiment of the present invention, the weight pillow and the support layer body are restrained by the tensile force of the holding sheet introduced by utilizing the load of the load layer described above.

INDUSTRIAL APPLICABILITY The present invention can provide a structure of an improved base having a high restraining action by a holding sheet and a small amount of deflection deformation by a simple method, and a construction method thereof.
Further, the present invention has a structure of an improved foundation having a high bearing capacity by effectively suppressing loosening and fluidization of granules and filling materials constituting the improved foundation even when a repeated load such as an earthquake is applied. A construction method can be provided.

Perspective view of the improved substrate according to the present invention in which a part is omitted. An explanatory diagram of the construction method of the improved base, (A) is an explanatory diagram of the laying work of the holding sheet, (B) is an explanatory view of the installation work of the weight pillow, and (C) is an explanation of the construction work of the support layer body. Figure, (D) is an explanatory view of the temporary fixing work of the holding sheet. Explanatory drawing of other temporary fixing work of the holding sheet, (A) is an explanatory view of a form in which each upper surface of the holding sheet is temporarily fixed individually, and (B) is a separation of the upper surface of the holding sheet from the support layer main body. Explanatory drawing of the temporarily fixed form Partial sectional view of the improved foundation when the load of a heavy structure is applied Partial sectional view of the improved base according to another Example 1. Partial sectional view of the improved base according to another Example 2. Perspective view of the improved base according to another second embodiment In the explanatory view according to the other third embodiment, (A) is an explanatory view of a form in which the improved foundation is applied to support the concrete retaining wall, and (B) is an explanatory view of a form in which the improved foundation is applied to support the pipe. (C) is an explanatory diagram of a form in which the improved foundation is applied to support a soil structure.

Embodiments of the present invention will be described with reference to FIGS. 1 to 4.

<1> Outline of the improved base Explaining with reference to FIG. 1, the mat-shaped improved base 20 is spaced between the holding sheet 30 spread and laid on the ground 10 such as soft ground and the holding sheet 30. A pair of left and right weight pillows 40 placed apart from each other and a bottom surface 30a of a holding sheet 30 exposed inside the opposing weight pillows 40 are formed to have a layer thickness lower than the height of the weight pillows 40. It has a support layer main body 50, a weight pillow 40, and a loading layer 60 formed on the upper surface 30c of the holding sheet 30 that encloses the support layer main body 50.
In this example, a mode in which the improved base 20 is constructed on the ground 10 will be described.

<2> Holding sheet The holding sheet 30 is a sheet-like material or a net-like material having excellent tensile strength, and has dimensions that allow a plurality of weight pillows 40 and a support layer main body 50 to be wound together. There is.
The holding sheet 30 is not limited to one sheet, and a plurality of sheets may be laminated.
As the holding sheet 30, a water-permeable sheet can be applied, and practically, a geotextile such as a geogrid, a woven fabric, or a non-woven fabric is suitable.

<3> Weight pillow The weight pillow 40 is a flexible heavy object, and is between the anchor function for positioning the holding sheet 30 at a specific position on the ground 10 and the weight pillow 40 for forming the support layer main body 50. It has a molded form function that suppresses the expansion of the soil material that has been unwound, and a pulley function that transmits tension over the entire circumference of the holding sheet 30.

<3.1> Weight of the weight pillow The weight pillow 40 can withstand the rolling pressure (lateral pressure) of the support layer body 50 so that the lateral movement of the weight pillow 40 can be regulated when the support layer body 50 is formed. Has a weight.

<3.2> Example of a weight pillow The weight pillow 40 of this example is composed of a single large sandbag in which a filling material 42 is enclosed in a tubular bag body 41.
The material of the bag body 41 may be any of a cloth, a sheet material, and a mesh material as long as the permeation of the filling material 42 can be regulated.
The filling material 42 is made of a granular material such as a soil material.
The cross-sectional shape of the weight pillow 40 is, for example, circular or oval.
The cross-sectional shape, diameter, and total length of the weight pillow 40 can be appropriately selected according to the intended use.

<3.3> Other weight pillows The weight pillow 40 may be replaced with heavy objects such as concrete pipes and steel pipes in addition to sandbags.

<4> Support layer main body The support layer main body 50 is a mat-like material forming the skeleton of the improved base 20.
In this example, a form in which the support layer main body 50 is composed of granular materials 51 such as soil materials will be described.

<4.1> Dimensional relationship between the weight pillow and the support layer body The layer thickness of the support layer body 50 is smaller than the height of the single weight pillow 40.
In other words, the height of the weight pillow 40 is larger than the layer thickness of the support layer main body 50.
The reason for this dimensional relationship is that the weight pillow 40 functions as a molding form when the support layer main body 50 is rolled, and the height difference that occurs between the weight pillow 40 and the support layer main body 50. This is to apply a tensile force to the holding sheet 30 by utilizing.
The tensile force introduced into the holding sheet 30 increases according to the height difference between the weight pillow 40 and the support layer main body 50.

<5> Loading layer The loading layer 60 is a heavy layer formed on the upper surface 30a of the holding sheet 30 in a state where the weight pillow 40 and the support layer main body 50 are wound, and is made of, for example, granules such as soil material.
Since the loading layer 60 is a layer for applying a tensile force to the holding sheet 30, the layer thickness of the loading layer 60 can be appropriately selected according to the applied weight.

[Construction method]
The construction method of the improved base 20 will be described with reference to FIG.

<1> Laying work of holding sheet (Fig. 2 (A))
The holding sheet 30 is unfolded and laid on the ground 10.
It is not necessary to level the ground 10 smoothly, and there may be some unevenness.

<2> Installation work of weight pillow (Fig. 2 (A))
A plurality of sets of weight pillows 40 are placed on the holding sheet 30 manufactured in advance at intervals, and the bottom surface 30a of the holding sheet 30 is positioned by utilizing the weight of the weight pillows 40.
When the weight pillow 40 is placed, the bottom surface 30a of the holding sheet 30 exposed inside the weight pillow 40 is stretched to such an extent that a large slack does not occur.
Thus, the mat space S ₁ is formed inside the plurality of sets of the weight pillow 40.

<3> Forming the support layer body (Fig. 2 (B))
The granules 51 in the mat space S ₁ in which the bottom surface 30a of the holding sheet 30 is exposed out inoculated in layers to form a supporting layer body 50 to the inside of the weight pillow 40 compacting the granules 51 out sown.

<3.1> Layer thickness of the support layer main body The layer thickness of the support layer main body 50 is formed to be lower than the height of the weight pillow 40 to create a height difference between the weight pillow 40 and the support layer main body 50. Provide.

<3.2> Rolling of the support layer main body A compaction machine such as a road roller is introduced to roll the support layer main body 50.
Since the weight pillow 40 is given a weight sufficient to withstand the rolling pressure of the soil material, the weight pillow 40 does not move laterally due to the rolling pressure of the support layer main body 50.
In this way, the gravity-type weight pillow 40 supports the outward rolling pressure of the support layer main body 50 and reliably regulates the diffusion of the granular material 51. Therefore, a large compaction machine was introduced. The entire support layer main body 50 including the peripheral edge portion of the support layer main body 50 can be efficiently and safely compacted.

<3.3> Tension mechanism on the bottom of the seat If the soil material sprinkled in layers on the seat is compacted without installing the weight pillow 40, the seat will only follow the deflection deformation of the ground and become the seat. No tensile force is introduced.

On the other hand, in the present invention, since the peripheral edge of the bottom surface 30a of the holding sheet 30 is positioned in advance by using the weight of the weight pillow 40, the rolling compaction of the support layer main body 50 is performed on the bottom surface 30a of the holding sheet 30. When the loading load (the weight of the support layer main body 50 and the rolling pressure) acts, a tensile force is generated on the bottom surface 30a. The tensile force generated on the bottom surface 30a is held by the load of the weight pillow 40 and the support layer main body 50.

<4> Temporary fixing of the holding sheet (Fig. 2 (C))
The holding sheet 30 protrudes from the outside of the weight pillow 40. The holding sheet 30 protruding from the weight pillow 40 is wrapped around the weight pillow 40 and covered on the upper surface side of the support layer main body 50.
A plurality of sets of weight pillows 40 and the holding sheet 30 covered with the support layer main body 50 are tensioned to temporarily fix both ends of the holding sheet 30.
As a result, the portion of the holding sheet 30 wrapped around the weight pillow 40 is formed as the side surface 30b, and the portion of the holding sheet 30 temporarily fixed to the upper surface side of the support layer main body 50 is formed as the upper surface 30c.

<4.1> Temporary fixing means for the holding sheet In FIG. 2 (C), the holding sheet 30 is overlapped near the end of the upper surface 30c, and the fixing pin 31 is driven into the overlapping portion to temporarily fix the holding sheet to the support layer main body 50. It shows a fixed form.
As another temporary fixing means of the upper surface 30c of the holding sheet 30, for example, a fixing pin 31 may be driven into the support layer main body 50 to temporarily fix each upper surface 30c of the weight pillow 40 individually (FIG. 3 (FIG. 3). A)), the ends of the upper surface 30c may be connected by a connecting means 32 such as a rope or a connecting tool at a position separated from the support layer main body 50 (FIG. 3 (B)).

<4.2> Formation of tightening space Since there is a height difference between the weight pillow 40 and the support layer main body 50, the holding sheet is temporarily fixed by temporarily fixing the upper surface 30c of the holding sheet 30. space S ₂ is formed tightening between the upper surface 30c of the 30 and the upper surface of the support layer body 50.
Since the extension length of the upper surface 30c of the holding sheet 30 and the tightening space S ₂ affect the tensile force introduced into the holding sheet 30, the upper surface of the holding sheet 30 depends on the tensile force introduced into the holding sheet 30. the stretched length and size of the clamping space S ₂ of 30c may be selected.

Coated embodiment shown in FIG. 3 (A) Fig. 2 (C), and shows a mode of forming the fastening space S ₂ in a state in which both sides of the upper surface 30a of the holding sheet 30 is floated from the support layer body 50, FIG. the coated embodiment shown in 3 (B), to form a clamping space S ₂ in a state in which the entire upper surface 30a of the holding sheet 30 is floated from the support layer body 50.

<5> Tension work of the holding sheet by the loading layer (Fig. 2 (D))
The binding force of the holding sheet 30 is insufficient only by tensioning and temporarily fixing both ends of the holding sheet 30 wrapped around the weight pillow 40 and the support layer main body 50.
Therefore, in the present invention, the loading layer 60 is formed on the upper surface 30c of the holding sheet 30, and the load of the loading layer 60 is used to forcibly increase the binding force of the holding sheet 30.

<5.1> Tension mechanism of the holding sheet 30 Soil material or the like is sprinkled on the upper surface 30c of the holding sheet 30 to form a loading layer 60, and the loading layer 60 is held between the upper surface of the support layer main body 50 and the loading layer 60. The upper surface 30c of the sheet 30 is embedded and fixed.
By forming the loading layer 60 on the upper surface 30c of the holding sheet 30, a tensile force is generated on the upper surface 30c. Tensile force to the upper surface 30c gradually increases until disappears clamping space S _2.
In forming the loading layer 60, if the work of sprinkling the soil material is performed in advance of the temporary fixing portion of the upper surface 30c of the holding sheet 30, the temporary fixing portion of the upper surface 30c will not come off.

<5.2> Transmission of tensile force The tensile force generated on the upper surface 30c of the holding sheet 30 is transmitted to the bottom surface 30a through the side surface 30b wound around the curved surface of the weight pillow 40.
Since the tensile force has already been introduced into the bottom surface 30a, the tensile force acts on the side surface 30b through the bottom surface 30a and the top surface 30c.
Since the weight pillow 40 has a flexible structure, when the weight pillow 40 is tightened, the side shape of the weight pillow 40 changes to a rounded shape according to the winding shape of the holding sheet 30, and the weight pillow 40 is held. It becomes easy to introduce the tensile force over the entire circumference of the sheet 30.
By simply forming the loading layer 60 on the upper surface 30c of the holding sheet 30 in this way, a tensile force can be introduced over the entire circumference of the holding sheet 30.

<5.3> Restraint mechanism of the weight pillow The weight pillows 40 on both sides are strongly tightened by the tensile force acting on the side surface 30b of the holding sheet 30.
By tightening the weight pillow 40 through the holding sheet 30, the filling material 41 in the weight pillow 40 can be restrained between the support layer main body 50 and the holding sheet 30, and the filling material 41 can be loosened. Can be effectively prevented.

<5.4> Restraining mechanism of the support layer main body By introducing a tensile force over the entire circumference of the holding sheet 30, the restraining force acts on the entire support layer main body 50, and the amount of deformation of the support layer main body 50 is small. An improved base 20 is obtained.
In particular, since the band-shaped side surfaces 30b of the holding sheet 30 tighten the outer peripheral surfaces of the weight pillows 40 on both sides, the filling material in the weight pillows 40 is not loosened, so that the left and right side surfaces of the support layer main body 50 are Since it is sandwiched between the weight pillows 40 that have been altered to high rigidity, the desired rigidity (supporting force) can be secured even if the layer thickness of the improved base 20 is made thinner than before.

Various heavy structures are constructed on the upper part of the improved base 20 constructed in this manner according to the purpose of use.

<6> Supporting capacity of the improved base Next, the bearing capacity of the improved base 20 before and after loading a heavy structure will be described.

<6.1> About the bearing capacity of the heavy structure before loading The bearing capacity of the improved base 20 before loading of the heavy structure will be described with reference to FIG. 2 (D).
The whole of the granules 51 constituting the support layer main body 50 including the peripheral portion thereof is sufficiently compacted, and the weight pillow 40 and the holding sheet 30 exert a greater binding force.
The filling material 41 in the weight pillow 40 also exerts a large binding force through the holding sheet 30.
Therefore, the improved base 20 has a high bearing capacity even before loading a heavy structure.

<6.2> About the bearing capacity after loading the heavy structure The bearing capacity of the improved base 20 after loading the heavy structure will be described with reference to FIG. When the load F of the heavy structure acts on the improved base 20 and the improved base 20 bends and deforms following the subsidence of the ground 10, the binding force of the holding sheet 30 further increases, and the holding sheet 30 30 firmly restrains the weight pillow 40 and.
Therefore, the bearing capacity of the improved base 20 is significantly increased as compared with that before loading the quantitative structure.

As described above, in the present invention, it is possible to realize an improved base 20 having a high restraining action through the holding sheet 30 and a small amount of deflection deformation.
Therefore, even when a repetitive load such as an earthquake is applied, loosening and fluidization are effectively suppressed not only for the granules 51 constituting the support layer main body 50 but also for the filling material 41 in the weight pillow 40. be able to.

[Other Example 1]
Other examples will be described below, but in the description thereof, the same parts as those in the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

<1> Weight Pillow With reference to FIG. 5, another form of weight pillow 40 will be described.
In the previous embodiment, the embodiment in which the weight pillow 40 is composed of a single large sandbag has been described, but the weight pillow 40 may be composed of a plurality of sandbags 43 smaller than the large sandbag.

<2> A plurality of sandbags The basic configuration of the plurality of sandbags 43 is the same as the large sandbag described above, which includes a flexible bag body 41 and a filling material 42 to be sealed in the bag body 41.

<3> Construction method of heavy water pillows A plurality of sandbags 43 are used by stacking them in a bank shape on the upper surface of the holding sheet 30.
Since the construction method of the improved base 20 is as described above, detailed description thereof will be omitted.
In this example, a plurality of sandbags 43 are tightened with a holding sheet 30 to form an integrally structured weight pillow 40.
When the holding sheet 30 tightens the plurality of stacked sandbags 43, the side surface shape of the plurality of sandbags 43 facing the holding sheet 30 changes to a rounded shape according to the winding shape of the holding sheet 30. ..

In addition, in FIG. 5, in order to make it easy to understand, the stacking form of the plurality of sandbags 43 is simply illustrated. In reality, the adjacent sandbags 43 are in close contact with each other, and no large gap is formed between the adjacent sandbags 43.

<4> Effect of this example Since a small and lightweight sandbag 43 is used in this example, the handling of the sandbag 43 when constructing the weight pillow 40 is easier than that of a single large sandbag. Will improve.

[Other Embodiment 2]
The support layer main body 50 of another form will be described with reference to FIGS. 6 and 7.

<1> Support layer main body In the above embodiment, the support layer main body 50 is composed of granules 51 such as soil materials, but the support layer main body 50 is reinforced in a honeycomb shape by partitioning a large number of cells 52. It may be composed of the material 53 and the granular material 51 filled in the cell 52.
The three-dimensional reinforcing material 53 includes a plurality of cells 52 that are open at the top and bottom, the cells 52 are closed during transportation, and the three-dimensional reinforcing material 53 is used by being stretched at the time of laying.
As the granular material 51, a soil material, crushed stone or the like can be used.

<2> Construction method Since the construction method of the improved base 20 in this example is as described above, detailed description thereof will be omitted.
In particular, in this example, after the three-dimensional reinforcing material 53 is developed on the holding sheet 30, the granules 51 filled in the cell 52 are rolled to form the support layer main body 50.
As described above, the support layer main body 50 is formed inside the weight pillow 40, and the support layer main body 50 is restrained by the holding sheet 30 together with the weight pillow 40.
In this example, the holding sheet 30 does not individually cover the upper and lower surfaces of the three-dimensional reinforcing material 53, but the entire three-dimensional reinforcing material 53 is restrained by the continuous holding sheet 30.

<3> Effect of this example In this example, the three-dimensional reinforcing material 53 is installed inside the improved base 20, and the granular material 51 is restrained by the cooperation of the three-dimensional reinforcing material 53 and the holding sheet 30. The restraining effect of the granular material 51 is remarkably increased.
Therefore, not only can the improved base 20 be made thinner, but also the deflection deformation of the improved base 20 and the fluidization of the granules 51 through the weight pillow 40 and the holding sheet 30 can be effectively suppressed.

[Other Embodiment 3]
Explaining with reference to FIG. 8, a groove hole 11 having a size matching the improved base 20 to be constructed is opened in advance of the ground 10, and the improved base 20 is provided in the groove hole 11 by the process described above. You may build it.

FIGS. 8A to 8C show application examples of the improved base 20.
(A) shows a form in which the concrete retaining wall 12 is supported on the improved base 20, (B) shows a form in which the improved base 20 supports a pipe 13 such as a box culvert, and (C) shows the improved base 20. Shows a form in which a soil structure 14 such as a reinforced soil wall is supported.
The application of the improved base 20 is not limited to these heavy-duty structures, and can be applied to known heavy-duty structures.
Further, the improved base 20 is not limited to supporting heavy structures, and can be applied as trafficability of construction machinery and the like.

10 ... Ground 11 ... Groove hole 12 ... Concrete retaining wall 13 ... Pipe 14 ... Soil structure 20 ... Improved foundation 30 ... Holding sheet 30a ... Holding sheet Bottom surface 30b ... Side surface of holding sheet 30c ... Top surface of holding sheet 31 ... Fixing pin 32 ... Connecting means 40 ... Weight pillow 41 ... Bag body 42 ... Filling material 43 ... Sandbag 50 ... Support layer body 51 ... Granules 52 ... Cell 53 ... Three-dimensional reinforcing material 60 ... Loading layer S ₁ ... Mat space S ₂ ... Tightening space

Claims (10)

It is a mat-like improved base structure,
A hugging sheet spread on the ground and laid
A plurality of weight pillows placed on the holding sheet at intervals and
A support layer body formed by compacting the inside of the plurality of weight pillows,
It is composed of a loading layer formed on the upper surface of the holding sheet.
The layer thickness of the support layer body is smaller than the height of the weight pillow.
The holding sheet is wrapped around a plurality of weight pillows and support layers.
The upper surface of the holding sheet is embedded and fixed between the support layer main body and the loading layer, and is fixed.
The weight pillow and the support layer body are restrained by the tensile force of the holding sheet introduced by utilizing the load of the load layer described above.
Structure of the improved base. The improved base according to claim 1, wherein the support layer main body is composed of granules sprinkled and compacted on the bottom surface of a holding sheet exposed inside a plurality of weight pillows. Construction. The support layer main body is arranged on the bottom surface of a holding sheet exposed inside a plurality of weight pillows, and is composed of a three-dimensional reinforcing material having a plurality of cells and granules filled and compacted in the cells. The structure of the improved base according to claim 1, wherein the structure is characterized by the above. The structure of the improved base according to any one of claims 1 to 3, wherein the weight pillow is composed of a single sandbag or a plurality of stacked sandbags. The structure of the improved base according to claim 1, wherein the side surface of the holding sheet wound around and restrained by the weight pillow has a curved surface. It is a construction method of a mat-shaped improved base,
A plurality of weight pillows are placed on the holding sheet laid on the ground at intervals to position the bottom surface of the holding sheet.
A support layer body having a layer thickness smaller than the height of the weight pillow is formed on the bottom surface of the holding sheet exposed inside the plurality of weight pillows.
A load layer is formed on the upper surface of the holding sheet wound around the plurality of weight pillows and the support layer main body.
Construction method of improved base. The method for constructing an improved base according to claim 6, wherein granules are sprinkled on the bottom surface of a holding sheet positioned by the plurality of weight pillows and compacted to form a support layer main body. It is characterized in that a support layer main body is formed by a three-dimensional reinforcing material having a plurality of cells arranged on the bottom surface of a holding sheet positioned by the plurality of weight pillows and granules filled and compacted in the cells. The method of constructing the improved base according to claim 6. The method for constructing an improved base according to any one of claims 6 to 8, wherein the weight pillow is composed of a single sandbag or a plurality of stacked sandbags. The improved base according to any one of claims 6 to 9, wherein the weight pillow and the support layer main body are restrained by the tensile force of the holding sheet introduced by utilizing the load of the load layer described above. Construction method.

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