JP2021008727A - Lightweight banking structure, and production method of lightweight banking - Google Patents

Abstract

To provide a lightweight banking structure in which creation of irregularities such as steps or cracks on a road surface created by a rocking mode is suppressed.SOLUTION: A lightweight banking structure of the present invention (10) configured to be constructed on an inclined plane (21) of the ground (20) is provided with: foam resin material (2); concrete slabs (1) placed on the foam resin material (2); screw piles (3) fixing the concrete slabs (1) on the ground (20), wherein the screw piles (3) have a spiral convex part (31a) formed in a spiral shape toward a tip on its outer peripheral surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lightweight embankment structure and a method for producing a lightweight embankment.

In the lightweight embankment method using foamed resin blocks, a shaking table demonstration experiment using a full-scale model of the effects of earthquake motion is being conducted. As a result, it was confirmed that the road surface on the block made of expanded polystyrene (expanded polystyrene) (hereinafter, also referred to as EPS block) temporarily floats, but it is demonstrated that there is no problem in ensuring the stability of the embankment. did it.

However, in Non-Patent Document 1, countermeasures are assumed in case the EPS block, which is an elastic body, is damaged by a seismic motion, such as a cut-and-fill boundary such as a widened embankment or a step at a structure mounting portion, which impairs the road running function. There is a description about the necessity to keep it. In some cases, cracks and steps were generated on the road surface due to the deformation of the cutting boundary due to the actual earthquake, and it is necessary to suppress the deformation of the cutting boundary.

By the way, as a conventional lightweight embankment structure, for example, Patent Document 1 describes a structure in which an anchor is embedded and fixed in a supporting ground and an anchor is fixed to a concrete floor slab. In the structure described in Patent Document 1, the anchor is buried and fixed in a relatively hard ground such as rock.

Further, Patent Document 2 discloses a retaining wall structure constructed on a sloping land during civil engineering work such as roads, railways, and land development. In the structure described in Patent Document 2, a synthetic resin granule is filled as a backfill material between the foamed synthetic resin block and the inclined surface of the sloping ground. Further, the concrete floor slab is fixed in the horizontal direction by an anchor. With such a configuration, the collapse of the retaining wall structure is prevented.

Japanese Unexamined Patent Publication No. 2003-74060 Japanese Unexamined Patent Publication No. 11-100846

"Latest EDO-EPS Method" Styrofoam Civil Engineering Method Development Organization (ed.), Publisher: Science and Technology Books, published on December 16, 2016 p.103-104

By the way, in the lightweight embankment using the EPS block, the EPS block portion is 1/100 of the weight of the earth and sand, which is very lightweight. Then, in the pavement portion on the EPS block, a roadbed, asphalt, etc. are laid. As a result, the lightweight embankment has a top heavy structure with a relatively large upper weight. Therefore, when a large-scale earthquake such as a level 2 earthquake occurs, it is assumed that the shaking (up and down) will increase at the top (road surface). This phenomenon is called locking mode and has been confirmed by full-scale vibration experiments.

The anchor of the lightweight embankment structure described in Patent Document 1 is for fixing to relatively hard ground (for example, rock), and is for example, relatively soft ground (for example, sandy soil composed of earth and sand). It cannot be fixed to the road constructed by embankment). Therefore, the technique described in Patent Document 1 may be difficult to use if there is no bedrock or the like, the effect may not be sufficiently obtained even if it is constructed, and the installation cost is high.

Further, the retaining wall structure described in Patent Document 2 can prevent the retaining wall structure from collapsing due to sliding along an inclined surface. However, for example, there is room for improvement in fixing the retaining wall structure with an anchor in terms of suppressing the locking mode.

One aspect of the present invention is to realize a lightweight embankment structure capable of suppressing deformation such as steps and cracks on the road surface due to the locking mode, and a method for manufacturing the lightweight embankment.

As a result of diligent studies by the inventors to solve the above problems, it was found that the vertical vibration of the EPS block affects the locking mode, and the vertical direction of the EPS block is used to suppress the locking mode. It was considered that it is effective to suppress the vibration of the above, and the present invention was completed.

That is, in order to solve the above problems, the lightweight pile structure according to one aspect of the present invention is a lightweight pile structure constructed on an inclined surface of the ground, and is arranged on the foamed resin material and the foamed resin material. The concrete slab and the pile for fixing the concrete slab to the ground are provided, and the pile has a spiral convex portion formed spirally toward the tip portion on the outer peripheral surface thereof. is there.

The lightweight embankment structure according to one aspect of the present invention preferably includes a cushioning material arranged between the pile and the concrete slab.

Further, in the lightweight embankment structure according to one aspect of the present invention, it is preferable that the cushioning material functions as a formwork for forming a through hole provided in advance for installing the pile on the concrete floor slab.

Further, in the lightweight embankment structure according to one aspect of the present invention, the pile is fixed to the ground so that the angle at which the pile is installed is 90 ° ± 10 ° with respect to the concrete slab. preferable.

Further, in order to solve the above problems, the method for constructing a lightweight concrete according to another aspect of the present invention can penetrate a pile having a spiral convex portion formed spirally toward an end on an outer peripheral surface. A floor slab forming step of placing concrete on the ground or foamed resin material and then placing concrete on the foamed resin material and the ground to form a concrete slab, and after the concrete is cured, the pile. Includes a pile burying step of inserting the material into the cushioning material and burying the material in the ground.

According to one aspect of the present invention, it is possible to suppress deformation such as steps and cracks on the road surface due to the locking mode.

(A) is a cross-sectional view showing a schematic structure of a lightweight embankment structure according to an embodiment of the present invention, and (b) is an enlarged cross-sectional view of part A in (a). The schematic configuration of the screw pile provided in the lightweight embankment structure shown in FIGS. 1A and 1B is shown, FIG. 1A is a plan view, and FIG. 1B is a side view. The schematic configuration of the second buffer member provided in the lightweight embankment structure shown in FIGS. 1 (a) and 1 (b) is shown, (a) is a plan view, and (b) is a line AA of (a). It is a sectional view. It is sectional drawing for demonstrating the effect when the lightweight embankment structure shown in (a) and (b) of FIG. 1 is used for widening of a road ground, and (a) is a seismic motion when a screw pile is not provided. It is a cross-sectional view which shows the influence of the road ground with respect to, (b) is a sectional view which shows the influence of the road ground on the seismic motion when a screw pile is provided, and (c) is a cross-sectional view which shows the influence of a screw pile when it is not provided. It is sectional drawing which shows the reaction force degree with respect to the road ground of a foam resin material, (d) is the sectional view which shows the reaction force degree with respect to the road ground of a foam resin material when a screw pile is provided. It is sectional drawing for demonstrating the inclination angle of the inclined surface of the ground in the lightweight embankment structure which concerns on embodiment of this invention. It is sectional drawing for explaining the construction method of the lightweight embankment structure shown in (a) and (b) of FIG. 1, (a) shows the state after a floor slab forming process, (b) is a pile burying process. Indicates the state of.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to this, and various modifications can be made within the scope described, and the embodiment obtained by appropriately combining the technical means disclosed in different embodiments and examples. The form is also included in the technical scope of the present invention. Unless otherwise specified in the present specification, "A to B" representing a numerical range means "A or more (including A and larger than A), B or less (including B and smaller than B)". ..

FIG. 1A is a cross-sectional view showing a schematic configuration of a lightweight embankment structure 10 according to the present embodiment, and FIG. 1B is an enlarged cross-sectional view of part A in FIG. 1A. is there. FIG. 2 shows a schematic configuration of a screw pile 3 provided in the lightweight embankment structure 10 shown in FIGS. 1A and 1B, FIG. 2A is a plan view, and FIG. 2B is a plan view. ) Is a side view. 3A and 3B show a schematic configuration of a second buffer member 5 provided in the lightweight embankment structure 10 shown in FIGS. 1A and 1B, and FIG. 3A is a plan view of FIG. (B) is a sectional view taken along line AA of FIG. 3A.

As shown in FIG. 1A, the lightweight embankment structure 10 according to the present embodiment is constructed on the inclined surface 21 of the ground 20. The ground 20 on which the lightweight embankment structure 10 is constructed is soft ground such as sandy soil composed of earth and sand, and examples thereof include road ground, railroad ground, and land development ground. For example, when the ground 20 is a road ground, the lightweight embankment structure 10 is constructed for widening the road surface.

The lightweight embankment structure 10 includes a concrete floor slab 1, a foamed resin material 2 made of foamed resin, a screw pile 3, a first cushioning member 4, and a second cushioning member 5. A plurality of foamed resin materials 2 are laminated upward from the ground. The laminated body of the foamed resin material 2 has a structure in which the end portion on the ground 20 side is along the inclined surface 21. The concrete floor slab 1 is arranged on the laminated body of the foamed resin material 2, and is also arranged on the ground 20 beyond the cutting boundary 22 of the ground 20. The screw pile 3 is a pile that fixes the concrete floor slab 1 to the ground 20, and is buried and fixed in the ground 20 through the concrete floor slab 1. The screw pile 3 is fixed in the vicinity of the cutting boundary 22 of the ground 20.

The concrete floor slab 1 is provided on the uppermost foamed resin material 2 for non-landing adjustment, load distribution, fixing of the foamed resin block, and measures against buoyancy. The thickness (vertical direction) of the concrete floor slab 1 is preferably 100 to 300 mm. Further, in order to improve the strength of the concrete floor slab 1, preferably, lattice-shaped reinforcing bars are embedded as a base material inside the concrete floor slab 1. The covering thickness of the reinforcing bar is preferably 20 mm or more from the viewpoint of preventing deterioration due to oxidation of the reinforcing bar. The lightweight embankment structure 10 is not limited to the configuration in which the concrete slab 1 is provided on the uppermost foamed resin material 2, and an intermediate concrete slab is provided for each height of the foamed resin material 2. It may have a different configuration. In such a configuration, the uppermost concrete slab is provided on the uppermost foamed resin material 2 installed on the intermediate concrete slab. The screw pile 3 is provided on the uppermost concrete slab 1.

The foamed resin material 2 is not particularly limited as long as it is made of a material having light weight, strength and flexibility that can withstand the loading load, traffic load and the like of the lightweight embankment structure 10, but for example, expanded polystyrene (EPS) is used. It is preferable to have. The foamed resin material 2 is preferably a laminate formed by stacking a plurality of foamed resin blocks. As a result, the foamed resin material 2 can be easily installed.

The screw pile 3 is made of a metal material. Further, as shown in (a) of FIG. 1 and (a) and (b) of FIG. 2, the screw pile 3 has a pile main body 31 and an enlarged diameter flat plate portion 32. The pile body 31 has a tapered rod shape whose diameter decreases toward the tip portion. Further, the enlarged diameter flat plate portion 32 has a larger diameter than the pile main body 31 and has a flat plate shape, and is arranged on the side opposite to the tip end of the pile main body 31. The screw pile 3 has a structure in which the pile body 31 is embedded in the concrete floor slab 1 and the ground 20, while the diameter-expanded flat plate portion 32 is exposed to the outside. Further, the pile body 31 has a spiral convex portion 31a. The spiral convex portion 31a is a convex strip protruding from the outer peripheral surface of the pile body 31, and is formed in a spiral shape toward the tip portion.

Further, the first buffer member 4 has a donut disk shape, and the pile body 31 is inserted into the opening of the donut disk shape. Further, the first cushioning member 4 is provided between the concrete floor slab 1 and the enlarged flat plate portion 32 of the screw pile 3. Therefore, since the enlarged flat plate portion 32 of the screw pile 3 is in contact with the concrete slab 1 via the first cushioning member 4, damage to the concrete slab 1 due to earthquake motion can be prevented. The first cushioning member 4 is not particularly limited as long as it is made of a material having cushioning properties and flexibility, but for example, a rubber resin is preferable.

Further, the second cushioning member 5 has a cylindrical shape and is embedded in the concrete floor slab 1 as shown in FIGS. 1A and 1B and 3A and 3B. There is. The inner diameter of the second cushioning member 5 is larger than the diameter of the pile body 31. The pile body 31 of the screw pile 3 is configured to be inserted into the second cushioning member 5. Further, the second cushioning member 5 is arranged between the concrete floor slab 1 and the pile body 31. Therefore, since the pile body 31 of the screw pile 3 is in contact with the concrete slab 1 via the second cushioning member 5, damage to the concrete slab 1 due to earthquake motion can be prevented. The second buffer member 5 is not particularly limited as long as it is made of a material having light weight, cushioning property and flexibility, and is, for example, a foamed resin such as polystyrene, polyurethane, polyethylene, polypropylene, or a copolymer thereof. It is preferably a foamed resin.

In the configuration shown in FIG. 1, the first buffer member 4 and the second buffer member 5 were separate bodies. However, the lightweight embankment structure 10 according to the present embodiment is not limited to this configuration, and the first buffer member 4 and the second buffer member 5 may be integrally molded. Further, only the second cushioning member 5 may be provided, and a gap corresponding to the thickness of the first cushioning member 4 may be formed between the screw pile 3 and the second cushioning member 5.

Here, the lightweight filling structure 10 according to the present embodiment includes a screw pile 3 for fixing the concrete floor slab 1 to the ground, and the screw pile 3 is spirally formed on the outer peripheral surface thereof toward the tip portion. It has a spiral convex portion 31a. With this spiral convex portion 31a, the screw pile 3 is firmly fixed to the ground 20 even if the ground 20 is softer than the rock or the like. Therefore, the pull-out resistance and the shear resistance of the screw pile 3 with respect to the ground 20 increase. Therefore, the concrete floor slab 1 is firmly fixed in the vertical direction by the screw pile 3. As a result, the vertical vibration of the laminated body of the foamed resin material 2 due to the seismic motion is suppressed, so that it is possible to suppress deformation such as steps and cracks on the road surface due to the locking mode.

FIG. 4 is a cross-sectional view for explaining the effect when the lightweight filling structure 10 is used for widening the road ground, and FIG. 4A is a cross-sectional view of the road ground against seismic motion when the screw pile 3 is not provided. FIG. 4B is a cross-sectional view showing the influence of the road ground on the seismic motion when the screw pile 3 is provided. Further, FIG. 4C is a cross-sectional view showing the degree of reaction force of the foamed resin material 2 with respect to the road ground when the screw pile 3 is not provided, and FIG. 4D is provided with the screw pile 3. It is sectional drawing which shows the reaction force degree with respect to the road ground of the foamed resin material 2 in the case.

As shown in FIGS. 4A to 4D, when constructing a lightweight embankment structure for road widening or the like, a pavement portion 23 (roadbed material and asphalt pavement) is further provided on the upper surface of the concrete floor slab 1. To construct. Further, the pavement portion 23 may be provided with a road structure such as a guardrail 24.

As shown in (a) of FIG. 4, when the screw pile 3 is not buried and fixed in the ground, the pavement portion 23 sways due to the occurrence of an earthquake (depending on the response characteristics of the earthquake, especially vertical sway). A phenomenon that increases, that is, a locking mode occurs. As a result, steps and cracks occur in the vicinity of the cut boundary 22 of the road ground.

On the other hand, as shown in FIG. 4B, when the screw pile 3 is buried and fixed in the ground, the screw pile 3 is firmly fixed to the ground, so that the locking mode is suppressed even if an earthquake occurs. Will be done. As a result, the road traffic function can be ensured without any steps or cracks occurring in the vicinity of the cut boundary 22 of the road ground.

Further, when constructing a lightweight embankment structure on the inclined surface of the ground, the reaction force of the laminated body of the foamed resin material 2 to the ground increases as the distance from the inclined surface increases, and the side opposite to the inclined surface in the laminated body of the foamed resin material 2. The degree of reaction force at the portion of is the largest (see (c) and (d) of FIG. 4). As can be seen from the comparison of (c) and (d) of FIG. 4, when the screw pile 3 is buried and fixed in the ground, the pull-out resistance of the screw pile 3 to the ground 20 is large, so that the foamed resin with respect to the ground The degree of reaction force of the material 2 can be reduced.

Further, due to deformation of the road ground or the like after the occurrence of an earthquake, there is a possibility that long-term compression deformation may occur in the foamed resin material 2 having a lightweight embankment structure. According to the lightweight embankment structure 10 according to the present embodiment, steps and cracks in the road ground due to such long-term compressive deformation of the foamed resin material 2 can be suppressed.

Further, for example, the conventional anchor used for the lightweight embankment structure described in Patent Document 1 has a length of 7 m or more and is buried and fixed in the ground every 4 m or less in the case of a ground anchor. Then, in order to fix such a large-sized anchor to the ground, temporary work and the use of heavy machinery are required, and further, large-scale work such as placing concrete is required. Therefore, there is a problem that the cost increases. On the other hand, in the lightweight embankment structure according to the present embodiment, even if the length of the screw pile 3 is relatively short, the screw pile 3 can be buried and fixed in the ground. Therefore, the screw pile 3 can be fixed to the ground by a relatively simple construction. The dimensions of the screw pile 3 are preferably φ = 50 to 150 mm and a length of 1000 to 3000 mm, for example, φ = 76 mm and a length = 1600 mm. Further, the screw pile 3 is buried and fixed in the ground at intervals of 1 to 2 m, for example. The installation interval shall be determined by the relationship between the generated tensile force and the pull-out resistance force of the screw pile 3.

The angle of the screw pile 3 with respect to the concrete floor slab 1 is not particularly limited as long as it can suppress the locking mode described above. Preferably, the screw pile 3 is fixed to the ground 20 so that the angle with respect to the concrete slab 1 is 90 ° ± 10 ° (vertical). When the angle of the screw pile 3 with respect to the concrete floor slab 1 is within the above range, deformation such as steps and cracks on the road surface due to the locking mode can be more reliably suppressed.

Further, the screw pile 3 may be installed on the ground 20 or the foamed resin material 2 as long as the spiral convex portion 31a can be buried in the ground 20. Good. However, as shown in FIG. 1A, the material directly under the concrete floor slab 1 is the earth and sand on the ground 20 side with the cut embankment boundary 22 as the boundary, while the foamed resin material 2 is on the lightweight embankment structure 10 side. ing. Since the materials of the members configured with the cut-and-fill boundary 22 as the boundary are different in this way, the cut-and-fill boundary 22 is a portion that is likely to be deformed by the earthquake motion. Therefore, preferably, the screw pile 3 is installed so that the spiral convex portion 31a is buried in the soil of the cutting boundary 22.

FIG. 5 is a cross-sectional view for explaining the inclination angle of the inclined surface 21 of the ground 20 in the lightweight embankment structure according to the embodiment of the present invention. The back slope U of the ground 20 shown in FIG. 5 is 1: 1.0.

Further, as shown in FIG. 5, in the lightweight embankment structure 10 according to the embodiment of the present invention, when the height of the lightweight embankment structure 10 is H and the width of the lightweight embankment structure 10 in the transverse direction is B, H It is constructed so that / B is 0.8 or less (H / B ≦ 0.8). When the H / B exceeds 0.8, it becomes necessary to attach a ground anchor or the like to the lightweight embankment structure 10. If the structure is such that H / B ≦ 0.8, it is not necessary to attach a ground anchor or the like, and deformation such as steps and cracks on the road surface due to the locking mode can be suppressed by the screw pile 3.

The lightweight embankment structure 10 is generally constructed (constructed) by the EPS embankment method. The lightweight embankment structure 10 is constructed by, for example, the construction method specified in "EDO-EPS Construction Method Design and Construction Standards (Draft) Issued: November 2014, Styrofoam Civil Engineering Construction Method Development Organization". Specifically, the lightweight embankment structure 10 is constructed (manufactured) by, for example, the following method. First, the foamed resin material 2 is laminated on the ground 20, and the concrete floor slab 1 is formed on the uppermost foamed resin material 2. The concrete floor slab 1 is formed by placing reinforcing bars in a grid pattern and then placing concrete.

The method for constructing the lightweight embankment structure 10 according to the present embodiment (also referred to as a method for manufacturing the lightweight embankment structure 10) is a method suitable for burying the screw pile 3 in the ground 20. More specifically, the method for constructing the lightweight embankment structure 10 includes a floor slab forming step of forming a concrete floor slab 1 and a pile burying step of burying a screw pile 3 in the ground 20. 6A and 6B are cross-sectional views for explaining a method of constructing the lightweight embankment structure 10. FIG. 6A shows a state after the floor slab forming step, and FIG. 6B shows a pile burying step. Indicates the state.

In the concrete floor slab forming step, a cylindrical second cushioning member 5 on which the screw pile 3 can be installed is installed on the ground 20 or a laminated body of the foamed resin material 2. Then, after the second cushioning member 5 is installed, concrete is cast on the laminated body of the foamed resin material 2 and the ground 20 to form the concrete floor slab 1. As shown in FIG. 6A, in the state after the concrete slab forming step, the cylindrical second cushioning member 5 is embedded in the concrete slab 1. When the screw pile 3 is penetrated through the concrete slab 1 and buried in the ground 20, a through hole is formed in advance in the concrete slab 1 in order to install the screw pile 3 in the concrete slab 1. The second cushioning member 5 functions as a formwork for forming the through hole in the concrete floor slab 1. Further, it also functions as a positioning member for determining the position of the screw pile 3 with respect to the concrete floor slab 1.

In the pile burying step, after the concrete is hardened, the screw pile 3 is inserted into the cylindrical second cushioning member 5 and buried in the ground 20 so that the vertical movement of the concrete floor slab 1 is suppressed. More specifically, as shown in FIG. 6B, the screw pile driving machine B is used in the pile burying process. The screw pile driving machine B rotates the screw pile 3 and moves it up and down at an angle orthogonal to the concrete slab 1.

In the pile burying step, first, the second cushioning member 5 is installed as a formwork in advance, and the concrete floor slab 1 is placed. Then, after curing, the donut disk-shaped first buffer member 4 is attached to the screw pile 3 in that state, and the screw pile 3 is attached to the screw pile driving machine B. The screw pile 3 penetrates the second cushioning member 5 embedded in the concrete floor slab 1, and pushes the earth and sand of the ground 20 in the vertical direction by the rotation of the spiral convex portion, and advances to the inside of the ground 20. Then, when the first cushioning member 4 comes into contact with the concrete floor slab 1, the driving of the screw pile 3 by the screw pile driving machine B is stopped, so that the lightweight embankment structure 10 is constructed.

Generally, in the construction of making a hole in a concrete member such as a concrete floor slab 1, a paper formwork called a void pipe is used. In a general method, after installing the void pipe, concrete is poured. Then, after the concrete is hardened, the void pipe can be removed to manufacture a concrete member having holes.

Here, since the second cushioning member 5 used as the formwork of the screw pile 3 has a function of buffering between the concrete floor slab 1 and the screw pile 3, it is not necessary to remove it from the lightweight embankment structure 10. That is, in the method for constructing the lightweight embankment structure 10 according to the present embodiment, when the concrete floor slab 1 is formed, the second buffer member 5 which is a constituent member of the lightweight embankment structure 10 is also used as a formwork. Therefore, as compared with the general method, it is not necessary to remove the formwork, and the workability is improved.

As described above, in the lightweight embankment structure 10 according to the present embodiment, the screw pile 3 is used as a pile to be fixed to the ground 20 in order to suppress the lifting of the lightweight embankment structure 10 at the time of an earthquake and the step or crack at the cut-and-fill boundary 22. Is provided. As a result, even if the ground 20 is soft ground, the pull-out resistance and shear resistance of the screw pile 3 increase. As a result, even if an earthquake occurs, deformation such as steps and cracks on the road surface due to the locking mode is suppressed.

Further, in order to avoid damage to the concrete slab 1 due to earthquake motion, a first cushioning member 4 and a second cushioning member 5 are provided between the concrete slab 1 and the screw pile 3. Further, by using the second cushioning member 5 of the first cushioning member 4 and the second cushioning member 5 as a formwork when placing the concrete floor slab 1, damage prevention and workability of the concrete floor slab 1 are prevented and workability is improved. And both are realized.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

The lightweight embankment structure according to one aspect of the present invention is used, for example, for civil engineering work such as roads, railways, and land development.

1 Concrete floor slab 2 Foamed resin material 3 Screw pile 4 1st cushioning member 5 2nd cushioning member (cushioning material as formwork)
10 Lightweight embankment structure 20 Ground 21 Inclined surface 31a Spiral convex part

Claims (5)

It is a lightweight embankment structure built on the slope of the ground.
Foamed resin material and
A concrete floor slab placed on the foamed resin material and
A pile for fixing the concrete slab to the ground is provided.
The pile has a lightweight embankment structure having a spiral convex portion formed spirally toward the tip portion on the outer peripheral surface thereof. The lightweight embankment structure according to claim 1, further comprising a cushioning material arranged between the pile and the concrete slab. The lightweight embankment structure according to claim 2, wherein the cushioning material functions as a formwork for forming a through hole provided in advance for installing the pile on a concrete floor slab. The lightweight embankment according to any one of claims 1 to 3, wherein the pile is fixed to the ground so that the angle at which the pile is installed is 90 ° ± 10 ° with respect to the concrete slab. Construction. After arranging a cushioning material capable of penetrating a pile having a spiral convex portion formed spirally toward the tip on the outer peripheral surface on the ground or foamed resin material, concrete is placed on the foamed resin material and the ground. The floor slab forming process of placing and forming a concrete floor slab,
A method for manufacturing a lightweight embankment structure, which comprises a pile burying step of inserting the pile into the cushioning material and burying the pile in the ground after the concrete is hardened.

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