JP2000080637A - Ground reinforcing structure and ground reinforcing construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground reinforcing structure having little settlement, high strength and a large ultimate bearing capacity and improving a traffic vibration damping effect and a vibration control effect by arranging and stacking multiple sandbags, and practically integrating the sandbags constituting a stratified object. SOLUTION: A bag-like object integrated with a cord-like object is used to form a sandbag 2 in advance, and multiple sandbags 2 are connected by attached cords. Two or more stratified objects 4 arranged with the sandbags 2 are stacked, and a ground reinforcing structure 1 practically integrating the sandbags 2 constituting one or more stratified objects 4 is formed. When two or more layered product 4 are used, the length of the bottom side of an upper stratified object 4 is made the length of the bottom side of a lower stratified object 4 or below. A foundation 6 is formed on the reinforcing structure 1 to suppress ground settlement, and the soil grains in the sandbags 2 below the foundation 6 are expanded by an upper mount load. The sandbags 2 themselves are solidified by the reaction of the sandbags 2, the sandbags 2 are integrated with the foundation 6 of a building to exhibit a high hearing capacity, and the settlement into the ground 5 can be largely suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground reinforcement structure and a construction method using sandbags.

[0002]

2. Description of the Related Art Conventionally, as a method of reinforcing a soft ground or a ground requiring reinforcement or forming a reinforcing layer on the ground,
The following are known. (1) Laying or stacking sandbags to reinforce the ground surface,
Repair the collapsed part. (2) Wrap a part of the soil of the soft ground with a sheet-like material, or lay a sheet-like material on the surface of the ground, fill the soil with the soil, and wrap the embankment with at least the surrounding extra sheets to fill the soft ground. Form a stable embankment on top. (3) Filling the double-structured portion of a sheet-like material such as a woven fabric having a double-structured portion such as a column laid on soft ground with earth and sand to form a reinforcing layer.

[0003] However, these ground reinforcement methods have the following disadvantages. In the case of the method (1), the movement of the soil particles in the sandbag is restrained by the action of the outer bag, but the individual sandbags do not form a reinforced layer as a whole, and the surface layer is harder than the ground. It has a strong repair character and is generally used for disaster repair. In the case of the method (2), since the entire soil particles are wrapped in a sheet-like material, the force for restraining the movement between the soil particles is weak, and unequal settlement is likely to occur with respect to the settlement of the embankment portion.
It is difficult to obtain support. In the case of the method (3), a columnar portion or the like filled with earth and sand is formed in a state of being connected by sheets at intervals, and it is difficult to form a strong reinforcing layer integrally covering the ground.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned disadvantages, has less settlement, has a high strength and a large ultimate support force, and has a high traffic vibration damping effect and a high vibration damping effect. To provide a safe, simple and earth-friendly ground reinforcement structure and construction method.

[0005]

SUMMARY OF THE INVENTION The present invention relates to (1) a layered structure obtained by arranging or laminating a plurality of sandbags, wherein the sandbags constituting the layered material are substantially integrated. A reinforcing structure, (2) a ground reinforcement structure, which is a layered product obtained by arranging or laminating a plurality of sandbags, wherein the sandbags constituting the layered product are substantially integrated by a cord-like material;
(3) a ground reinforcing structure in which a plurality of sandbags are arranged or stacked and the sandbags constituting the layered material are wrapped and substantially integrated with a sheet-like material; A) a ground reinforcement structure in which two or more layered materials in which a plurality of sandbags are arranged are stacked, and sandbags constituting the layered material are substantially integrated in at least one layer; Is a ground reinforcing structure in which two or more layered materials are arranged in a row and sandbags constituting the layered material are substantially integrated in at least one layer, and an arbitrary layered material (X) A ground reinforcement structure in which the length of the bottom of the layered object (Y) laminated on the upper part is less than or equal to the length of the bottom of the layered object (X);
(5) A ground reinforcement method for laying the ground reinforcement structure according to any of (5) on the ground; (7) Laying the ground reinforcement structure according to any of (1) to (5) on the ground; (8) A ground subsidence prevention method for a building that forms a building on top of a reinforcement structure, wherein the ground reinforcement structure according to any one of (8), (1) to (5) is installed on the ground, and the ground reinforcement structure is provided. And a method for improving the seismic control of a building that forms a building on top of a building.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The sandbag used in the present invention is basically a bag made of a sheet material such as cloth, paper, nonwoven fabric or the like, which has been conventionally used, filled with earth and sand, gravel and the like. The material to be filled into the sandbag is not limited to earth and sand, gravel and the like, and may be any material such as granular material and fibrous material.
Fillable materials include crushed stone, sand, soil, granulated slag,
Concrete waste, asphalt waste, and the like can be given.
The particle size, form, density, etc. of the filler may be appropriately set according to the purpose.

[0007] The size and shape of the sandbag are not particularly limited, but those having a relatively flat shape such as a bale shape are easy to handle,
The sandbag can be suitably used in view of workability and reinforcing effect, and the size of the sandbag is not particularly limited.
Those having a thickness of about 0 cm to 1 mm and a thickness of about 5 cm to 30 cm can be widely used. If the size of the sandbag is large, the reinforcing effect is improved, but the handleability and workability are likely to be reduced. The size of the sandbags may vary from individual to individual,
From the viewpoint of the reinforcing effect and the like, it is preferable to use sandbags having substantially the same shape.

[0008] An excellent ground reinforcement structure can be obtained by arranging or laminating the sandbags to form a layered material and substantially integrating the sandbags constituting the layered material. The method of integrating the sandbags is not particularly limited, and examples thereof include a method of integrating using a string-like material (rope, chain, or the like) or a sheet-like material, and a method of integrating with a glue or a hook-and-loop fastener. From the viewpoint of workability and environment, it is preferable to integrate them with a string and / or sheet. Of course, as long as the effects of the present invention are not impaired, sandbags that are not integrated with other sandbags may be used in combination.

As a method of integrating using a string-like material,
For example, the following method can be used. (1) A method in which a sandbag is manufactured using a bag-like material in which a string-like material is integrated in advance, and then a plurality of sandbags are connected using a string attached to the sandbag. (2) A method of manufacturing a sandbag having several through holes 2 and connecting a plurality of sandbags by penetrating a string-like material through the through holes (see FIG. 3A). (3) A method of manufacturing a sandbag having ears (through holes) on the surface and connecting a plurality of sandbags by penetrating a string-like material through the ears (see FIG. 3B). (4) A method in which a sandbag whose net 4 is entirely or partially covered is manufactured, and a plurality of sandbags are connected by penetrating a string-like material through a mesh portion of the net (see FIG. 3C). (5) A sandbag is sewn on both sides (both sides) of the sandbag so that both ends are free, and a plurality of soils are formed by connecting the strings of adjacent soil together. A method of connecting (see FIG. 3D). In particular, according to this method, the sandbags can be stably fixed in a lattice shape, so that excellent effects can be obtained. The string used is not particularly limited, and examples thereof include a rope, a chain, and the like. The material is not particularly limited, such as a fiber and a metal, but from the viewpoint of handleability and mechanical performance, a fiber rope is used. Is preferred.

A method of wrapping and integrating a plurality of sandbags with a sheet-like material can also be suitably used. The sheet-like material may wrap a part of the sandbag as shown in FIG. 3 (c), or may cover the entire plurality of sandbags.
From the viewpoint of the reinforcing effect and the like, it is preferable that the plurality of sandbags are completely wrapped by the bag-like material. Although the configuration of the sheet-like material is not particularly limited, a woven or knitted fabric, a non-woven fabric or the like can be suitably used, and a mesh-like material having a mesh size of 5 mm or more is used from the viewpoint of easy handling and easy fixing with a string-like material. Is preferred. It is preferable to use a sheet made of synthetic fiber from the viewpoint of mechanical performance, durability and the like.

In general, it is well known that when a load is applied from above the ground surface, the dense ground causes volume expansion due to dilatancy caused by the load. When there is no restraint force, this volume expansion is absorbed by the surrounding ground and causes the ground to rise or sink, but when such a structure is used, the expansion force is applied to the reaction force of the sandbag, that is, the internal effective stress σ. Can be changed to If the internal effective stress σ increases, the soil shear strength τ _f = σ · tan _φ increases, and the entire sandbag acts as a large foundation with deep roots, and the bearing capacity increases dramatically. If the sandbags are used individually without being integrated, the individual sandbags will sink and move due to the overload, but by integrating the sandbags, the whole can be made into one large lump, A large reaction force is obtained, and these expansion forces can be converted to internal stress.

In the present invention, a more excellent reinforcing effect can be obtained by integrating the sandbags with a cord-like material and wrapping the sandbags with a sheet-like material and integrating them. At this time, it is not necessary that all of the sandbags integrated by the sheet-like material need to be integrated by the string-like material, but all of the plurality of sandbags integrated by the string-like material are wrapped and integrated by the sheet-like material. In this case, a more excellent reinforcing effect can be obtained.

Further, in the present invention, two or more layered materials in which a plurality of sandbags are arranged are laminated, and sandbags constituting the layered material are substantially integrated in at least one layer (partially). (There may be a sandbag that is not integrated with the ground.) By using the ground reinforcing structure, the soil reinforcing effect can be further enhanced. Specifically, as shown in FIG. 1 (a), a method of integrating sandbags constituting one layer (preferably the lowermost layer), and as shown in FIG. 1 (b), a sandbag constituting a layered material for each layer. How to integrate,
As shown in FIG. 1 (c), there is a method of integrating the entire ground reinforcement structure. Needless to say, a plurality of layered materials in which the sandbags are substantially integrated may be laminated by using such a method, and the entire laminated body may be integrated with a bag-shaped material or the like. From the viewpoint of the reinforcing effect, a method of integrating sandbags constituting a layered material for each layer as shown in FIG. 1B or a method of integrating the entire ground reinforcing structure as shown in FIG. It is preferable to employ the reinforcing member, so that the ultimate supporting force of the entire reinforcing structure can be increased. In particular, each layer is integrated independently (Fig. 1
(B)) is preferable because, when a load is applied thereon, the reaction force of the entire reinforcing soil layer can be easily obtained and it is easy to tighten tightly.

The method of laying the sandbags is not particularly limited, but it is preferable to lay them substantially parallel as shown in FIG. 1 or to laminate them as shown in FIG. When laying or laminating sandbags, it is desirable that the sandbags be sufficiently contacted so as not to form gaps, and that when sandbags are connected or encased, they should be integrated so as not to cause slippage or displacement as much as possible. In some cases, two or more rows of sandbags may be arranged to form a layered body. The number of sandbags to be laid is not particularly limited, and is preferably set as appropriate according to the size of the ground or the like.

At this time, when the ground reinforcing structure is a laminate of two or more layers, from the viewpoint of the reinforcing effect, the bottom of the layered material (Y) laminated on the arbitrary layered material (X) is considered. It is preferable to lay so that the length is equal to or less than the length of the bottom side of the layered object (X). Specifically, as shown in FIG. 1, there is a method of stacking in multiple stages so that the cross section becomes triangular. When sandbags of substantially the same size are used, a desired structure can be easily obtained by reducing the number of sandbags constituting one layer. Each time one layer is stacked, the number of sandbags is 1-2
More preferably, the number is reduced by one, especially one by one. Although the reinforcing effect can be obtained even if the length of the bottom of the layered material (Y) exceeds the length of the bottom of the layered material (X), too much force is applied to the reinforcing layers on both sides of the foundation near the ground surface. Because it does not hang, it may be difficult to improve the supporting force. In such a case, the reinforcing effect can be enhanced by wrapping and integrating the entire sandbag with the sheet. The number of layers constituting the ground reinforcing structure is not particularly limited as long as it is one or more. Particularly, when the number of layers is 3 to 5, an excellent reinforcing effect is exhibited.

The method for laying the ground reinforcing structure of the present invention is not particularly limited. A method of laying first over the area, laminating and then integrating them together with a rope, etc., and laying a large, closable sheet-like material or net-like bag-like material that finally forms a mat shape on the ground ,
A method in which sandbags are stacked so as to be arranged side by side, and the bag-like body is closed to integrate the whole sandbags, while the sandbags are sequentially and sufficiently contacted on a sheet-like material laid on the ground (in some cases, There is a method of laying or laminating them together (integrating them), covering an extra sheet-like material from the periphery onto a sandbag, wrapping and integrating them, or a method of combining these methods.

Next, by forming a building (the foundation of the building or the like) on the ground reinforcing structure of the present invention, land subsidence can be efficiently suppressed (see FIG. 2). In this case, the soil particles in the sandbag below the foundation expand due to the overload, and the sandbag itself becomes hard due to the reaction force of the sandbag and is integrated with the foundation of the building, thereby exhibiting a high supporting force. Moreover, since the reinforcing layer is integrated over a wide area, it is suppressed from sinking largely in the ground. Of course, not only when a building is formed, but also when land or the like is buried on the ground reinforcement structure of the present invention, land subsidence can be efficiently suppressed. Further, since the ground reinforcement structure has an extremely high effect of damping traffic vibration and seismic motion, forming a building on the ground reinforcement structure can greatly improve the vibration control performance of the building. More specifically, 1 to 10
The acceleration spectrum ratio, which indicates the rate of attenuation of the acceleration with respect to the frequency in Hz, is 1 in both the horizontal and vertical directions.
/ 5 or less, especially about 1/10 or less.

[0018]

[Embodiment 1] 1/1 having ears (connection holes)
Zero model sandbags (4 cm x 5 cm x 1.5 cm) are connected with a rope and wrapped in a fiber mesh bag for each layer to produce each layered body. A ground reinforcement structure was laid on the ground (bottom layer: 8 sandbags, 6th
Layer: 3 sandbags). The relationship between the amount of settlement and the load when an overload was applied to the ground reinforcement structure was measured using an autograph manufactured by Shimadzu Corporation. FIG. 5 shows the results. FIG. 5 also shows the settlement amount when the ground reinforcement structure is not used.

[Embodiment 2] 1 /
Four models of sandbags (15 cm × 5 cm × 2.5 cm) are stacked in a six-tiered form, and the entire ground reinforcement structure is wrapped and integrated with a fiber mesh bag-like material. 6
It was laid on the ground like. The relationship between the amount of settlement and the load when an overload was applied to the ground reinforcement structure was measured using an autograph manufactured by Shimadzu Corporation. FIG. 7 shows the results. FIG. 7 also shows the amount of settlement when no ground reinforcement structure is used. Although it is a result of an indoor model test, when the ground reinforcement structure of the present invention is laid, the ultimate support force of 8 to 10 times is obtained as compared with the case of no reinforcement, indicating the usefulness of the method.

Example 3 Sandbags sewn on both sides with connecting strings (about 40 cm × about 40 cm × about 10 cm: FIG. 3)
(See (d)) Five were buried in the ground as shown in FIG. 8, and the sandbags in the lower two stages were connected and fixed to each other by the strings on both sides. A concrete plate for stably fixing the acceleration detector was placed on the ground reinforcing structure, and an acceleration detector “VP-5122” manufactured by IMV was installed thereon. In addition, to measure the vibration applied to the ground, both horizontal and vertical acceleration detectors were installed on the ground adjacent to the ground reinforcement structure (detected via a plate for stable installation on the ground). Vessel). 3 to 3
Vibration was applied by hitting the ground 4 m away with a wooden mallet in the vertical direction, and the vibration acceleration transmitted to the ground and the sandbag was measured. When the ratio of the vibration acceleration transmitted to the sandbag to the vibration acceleration transmitted to the ground (acceleration spectrum ratio) was obtained, the results shown in FIGS. 9 and 10 were obtained. FIG. 9 shows the horizontal acceleration spectrum ratio with respect to the frequency, and FIG. 10 shows the vertical acceleration spectrum ratio with respect to the frequency. The lower the acceleration spectrum ratio, the greater the vibration damping effect and the better the vibration damping property. It can be said that. The ground reinforcement structure of the present embodiment has a vibration frequency of 1 to 10 Hz, which is generally regarded as a seismic motion.
It can be seen that the acceleration spectrum ratio with respect to the vibration wave is small, and excellent vibration damping effect and vibration damping effect are obtained.

[0021]

According to the present invention, the individual sandbags constituting the ground reinforcement structure are held in a state where the sand is wrapped compactly and is divided into small pieces, so that the structure is largely collapsed or flows. It is integrated with a string, a rope, a sheet-like material, etc., and when the sandbags are laid in contact with each other, a load is applied between the sandbags due to friction caused by the bag body. At that time, the reinforcing layer formed of the aggregate of the sandbags is hardened by the reaction force obtained from the sandbags, and is reinforced as an integral layer, so that a high supporting force is obtained.
In addition, since the reinforcing layer is hardened over a large area and integrated with high strength and formed on the ground, the sandbag constituting the surface of the reinforcing layer sinks largely in the ground or slides on the ground. Without any problem, a stable reinforcing layer can be formed on the ground. INDUSTRIAL APPLICABILITY The method of the present invention can be carried out so that small sandbags are sequentially integrated into a mat without bringing in large equipment, and is suitable for ground reinforcement on soft ground or unstable slopes. Furthermore, since the ground reinforcement structure of the present invention has an excellent vibration damping effect, the vibration control can be remarkably improved by forming a building on the ground reinforcement structure.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example in which one example of a ground reinforcement structure of the present invention is laid on the ground.

FIG. 2 is a schematic diagram showing an example in which an example of the ground reinforcement structure of the present invention is laid on the ground, and a foundation of a building is formed above the ground reinforcement structure.

FIG. 3 is a schematic view showing an example of a sandbag used in the present invention.

FIG. 4 is a schematic diagram showing the shape of a ground reinforcement structure obtained in Example 1 of the present invention.

FIG. 5 is a schematic diagram showing a relationship between a load and a settlement amount of the ground reinforcement structure obtained in Example 1 of the present invention.

FIG. 6 is a schematic diagram showing the shape of a ground reinforcement structure obtained in Example 2 of the present invention.

FIG. 7 is a schematic diagram showing the relationship between the load and the amount of settlement of the ground reinforcement structure obtained in Example 2 of the present invention.

FIG. 8 is a schematic diagram illustrating a facility state of a ground reinforcement structure according to a third embodiment of the present invention.

FIG. 9 is a graph showing the ratio of the acceleration spectrum in the horizontal direction to the frequency measured in Example 3 of the present invention.

FIG. 10 is a graph showing the ratio of the acceleration spectrum in the vertical direction to the frequency measured in Example 3 of the present invention.

[Explanation of symbols]

 1: ground reinforcement structure 2: sandbag 3: sheet-like material 4: layered material 5: ground 6: foundation of building 7: earth and sand 8: through hole 9: ear 10: string 11: net Q: load

Claims (8)

[Claims] 1. A ground reinforcement structure which is a layered product obtained by arranging or laminating a plurality of sandbags, wherein sandbags constituting the layered material are substantially integrated. 2. A ground reinforcement structure comprising a plurality of sandbags arranged or stacked, wherein the sandbags constituting the layered material are substantially integrated by a string. 3. A ground reinforcement structure comprising a plurality of sandbags arranged or stacked, wherein the sandbags constituting the layered material are wrapped and substantially integrated with a sheet-like material. 4. A ground reinforcement structure in which two or more layered materials in which a plurality of sandbags are arranged are laminated, and sandbags constituting the layered material are substantially integrated in at least one layer. 5. A ground reinforcement structure in which two or more layered materials in which a plurality of sandbags are arranged are laminated, and sandbags constituting the layered material are substantially integrated in at least one layer. A ground reinforcement structure in which the length of the bottom of the layered material (Y) laminated on top of any layered material (X) is equal to or less than the length of the bottom of the layered material (X). 6. A ground reinforcement method in which the ground reinforcement structure according to claim 1 is laid on the ground. 7. A method for preventing ground subsidence of a building, wherein the ground reinforcement structure according to claim 1 is laid on the ground, and a building is formed above the ground reinforcement structure. 8. A method for improving seismic control of a building, wherein the ground reinforcement structure according to claim 1 is installed on the ground, and a building is formed above the ground reinforcement structure.