Earthen floor structure and its construction method

Abstract

This invention provides a floor slab structure with a space on the ground side and a method for constructing the same. [Solution] The floor structure 1 has a base plate 2 installed on the ground 9 on which the building is built, and a concrete layer 3 constructed on the upper surface (the other surface) of the base plate 2. The base plate 2 has alternating recesses 21 and protrusions 22 on one side (the lower side). The base plate 2 is positioned with one side facing the ground 9 and the protrusions 22 in contact with the ground 9. As the base plate 2, for example, a corrugated plate having alternating recesses and protrusions on one side and the other side is used.

Description

Technical Field

[0001] This invention relates to a dirt floor structure constructed on the ground for building a building and a construction method thereof.

Background Art

[0002] Conventionally, when recycled soil obtained by recycling the soil used for construction is adopted as backfill soil under the dirt floor, the backfill soil may abnormally expand due to some reason, causing the dirt floor to bulge, and problems such as cracks in the dirt floor or inability to open and close doors may occur. When such problems occur, it is very difficult to predict the future of the abnormal expansion. Therefore, it is necessary to once remove the dirt floor, also excavate and remove the backfill soil, and perform repair work to replace it with good-quality soil. In addition, when the conditions required for the ground are not met, it may be necessary to rebuild the building.

[0003] Patent Document 1 discloses a foundation structure for countermeasures against expansive ground for supporting a structure constructed on expansive ground. This structure is a structure in which a plurality of piles are driven into the ground, and a concrete slab floor is supported in a floating manner from the ground by the plurality of piles, and a space is secured below the concrete slab floor. By securing the space, even if the backfill soil expands, it is possible to prevent the concrete slab floor from rising.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the foundation structure disclosed in Patent Document 1 requires driving multiple piles into the ground and constructing the concrete slab floor on top of these piles, which has the disadvantage of being a large-scale structure and resulting in high construction costs. Furthermore, while this conventional technology can be used for new buildings, it is unsuitable for renovating and constructing a new foundation structure when the ground slab of an existing building site has risen.

[0006] The object of this invention is to provide a floor slab structure having a space on the ground side and a method for constructing the same. [Means for solving the problem]

[0007] The earthen floor structure of this invention is characterized in that, in order to solve the above problems, it comprises a base plate having alternating recesses and protrusions on at least one side, with the one side facing the ground and the protrusions in contact with the ground, and a concrete layer constructed on the other side which is the upper side of the base plate.

[0008] With the above configuration, there is no need to lift the base plate above the ground, and the base plate can be installed directly on the ground, making construction easy and reducing construction costs. Between the ground and the base plate, a space is formed by the recess, for example, in the area of ​​half the base plate. Therefore, even if the ground is expansive, the soil that rises due to expansion will move into the space and will not lift the base plate, thus reducing the uplift of this floor structure.

[0009] The base plate may be a corrugated plate having alternating recesses and protrusions on one side and the other side. Alternatively, the base plate may be a plate member in which a plurality of rectangular members are fixed at intervals to one side of a flat plate-shaped surface material.

[0010] Insulation material may be provided in the space formed by the ground and the recess in the base plate. This makes it possible to suppress the transfer of heat between the floor structure and the ground.

[0011] The above-mentioned insulating material may have the property of shrinking, which reduces its volume when subjected to pressure. In this case, even if the ground is expansive, the soil that has risen due to expansion can enter the space without being blocked by the insulating material.

[0012] A support member for supporting the base plate may be placed in the space formed by the ground and the recess of the base plate. This prevents deformation of the base plate when the concrete layer is constructed on the other side of the base plate.

[0013] The support member may have the property of shrinking, which reduces its volume when subjected to pressure. In this case, even if the ground is expansive, the soil that has risen due to expansion can enter the space without being blocked by the support member.

[0014] The structure comprises an underground beam positioned within the ground, and a wall-like rising section installed on the underground beam, with its upper side projecting upward from the ground. A sealing material may be placed at the boundary between the edge of the base plate and the wall-like rising section. This prevents fresh concrete from flowing from the boundary into the ground when forming the concrete layer on the other side of the base plate.

[0015] Furthermore, the method for constructing a floor structure according to this invention is a method for constructing a floor structure described in claim 1 by repairing a floor that has been uplifted due to an expansive ground, The process involves dismantling and removing the raised earthen floor, The process involves removing the soil excavated from the surface layer of the above-mentioned ground, and leveling the upper surface of this ground. The process involves placing the base plate on the flattened ground, with one side of which the recess and protrusion are formed facing the ground and the protrusion in contact with the ground, The process involves placing a sealant at the boundary between the existing wall-like rising section and the base plate, The step of producing the concrete layer portion on the other surface side which is the upper surface of the base plate; It is characterized by including.

[0016] In the case of the above method, even if the dirt floor at the location where the building already stands is raised, a new dirt floor structure can be constructed relatively easily.

Effect of the Invention

[0017] In the case of the present invention, since the base plate can be directly installed on the ground, the construction is easy and the construction cost can also be reduced. Further, between the ground and the base plate, a space due to a recess is formed, for example, in about half of the area of the base plate. Therefore, even if the ground is a swelling ground, the soil raised by swelling enters the above space and does not lift the above base plate, so that the effect of reducing the swelling of this dirt floor structure can be achieved.

Brief Description of the Drawings

[0018] [Figure 1] It is an explanatory view showing the dirt floor structure of the embodiment. [Figure 2] It is an explanatory view showing a modification example of the dirt floor structure of the embodiment. [Figure 3] It is an explanatory view showing another modification example of the dirt floor structure of the embodiment. [Figure 4] It is an explanatory view showing the construction method of the dirt floor structure of the embodiment. [Figure 5] It is an explanatory view showing another modification example of the dirt floor structure of the embodiment.

Mode for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. As shown in FIG. 1, the dirt floor structure 1 of the embodiment has a base plate 2 installed on the ground 9 on which the building stands, and a concrete layer portion 3 constructed on the upper surface (the other surface) of this base plate 2. The ground 9 is composed of, for example, the in-situ ground 91, the backfill soil 92 (expansive ground) located on the in-situ ground 91, and the crushed stone 93 located on the backfill soil 92.

[0020] The base plate 2 has recesses 21 and protrusions 22 alternately on one surface side (the lower surface side). Recesses and protrusions are also alternately formed on the other surface side (the upper surface side) of the base plate 2. The other surface side of the recess 21 becomes a protrusion when viewed from the upper surface side, and the other surface side of the protrusion 22 becomes a recess when viewed from the upper surface side. As the base plate 2, for example, a corrugated plate such as a folded plate or a deck plate is used. The base plate 2 is arranged with the one surface side facing the ground 9 and the protrusion 22 in contact with the ground 9.

[0021] A sealing material 11 is arranged at the boundary between the edge of the base plate 2 and the upright upper surface of the waist wall 4 (wall-like upright upper part). The sealing material 11 is composed of, for example, a caulking material filled in the gap at the boundary location, but any material that can fill the gap may be used. For example, a thin plate may be driven into the gap as the sealing material 11. The waist wall 4 is arranged on the underground beam 5, and a leveling concrete portion 51 is located below the underground beam 5, and a crushed stone layer 52 is located below the leveling concrete portion 51.

[0022] The concrete layer portion 3 is produced by placing fresh concrete so that the reinforcing bars 31 are positioned inside, and the fresh concrete hardens. Spacer blocks (not shown) are arranged on the upper surface of the recess 21 on the other surface side (the upper surface side) of the base plate 2 (on the protrusion when viewed from above), and by these spacer blocks, a covering of concrete is ensured below and above the reinforcing bars 31. The distance from the lower end surface of the base plate 2 to the upper end surface of the concrete layer portion 3 (the thickness of the dirt floor structure 1) is set to about 150 mm to 250 mm.

[0023] With the above-described floor slab structure 1, there is no need to construct the base plate 2 in a way that lifts it from the ground 9. The base plate 2 can be installed directly on the ground 9, making construction easier and reducing construction costs. Between the ground 9 and the base plate 2, a space is formed by the recess 21 in an area of, for example, half the area of ​​the base plate 2. Therefore, even if the ground 9 has backfill soil 92 (expandable ground), the soil that rises due to expansion will enter the space formed by the recess 21 and will not lift the base plate 2, thus reducing the uplift of this floor slab structure 1.

[0024] A modified version of the floor structure 1 shown in Figure 2 is provided with insulation material 12 in contact with the upper and both side surfaces of the recess 21 of the recess 21 in the space formed by the ground 9 and the base plate 2. This insulation material 12 may be a standard shape such as expanded polystyrene foam. Alternatively, it may be spray-applied insulation material that is sprayed onto the recess 21 before the base plate 2 is installed so that the space is secured to some extent. Alternatively, it may be an amorphous fibrous insulation material such as rock wool or glass wool. With a structure having the above insulation material 12, heat transfer between the floor structure 1 and the ground 9 can be suppressed.

[0025] The insulating material 12 may have the property of shrinking, which reduces its volume when subjected to pressure. In this case, as shown in Figure 2, even if the ground 9 has backfill soil 92 (expandable ground), the soil that has risen due to expansion can enter the space without being blocked by the insulating material 12.

[0026] In the modified version of the floor structure 1 shown in Figure 3, a plurality of support members 13 are arranged in the space formed by the ground 9 and the recess 21 of the base plate 2, in contact with the upper surface of the recess 21 of the base plate 2 and supporting the base plate 2. This prevents deformation of the base plate 2 when pouring ready-mix concrete to the other side of the base plate 2 to construct the concrete layer 3. As the support members 13, concrete blocks, square timbers, polystyrene foam blocks, hard sponges, etc., can be used. The support members 13 are arranged, for example, every few meters in the extending direction of the recess 21.

[0027] The support member 13 may be made of a hard sponge or similar material, capable of supporting the base plate 2 to some extent, while also having the property of shrinking when subjected to pressure, thereby reducing its volume. In this case, as shown in Figure 3, even if the ground 9 has backfill soil 92 (expandable ground), the soil that has risen due to expansion can enter the space without being blocked by the support member 13.

[0028] Next, the construction method for the slab structure 1 of the embodiment will be described. As shown in Figure 4, the existing raised slab 8 is dismantled and removed. Furthermore, the existing crushed stone 930 is removed, the surface layer 920 of the existing backfill soil (expandable ground) 92 is scraped away, and the scraped surface layer 920 (backfill soil) is removed. The thickness of the scraped surface layer 920 is set to ensure the thickness of the slab structure 1 to be constructed, the thickness of the base plate 2, and the thickness of the newly installed crushed stone 93. Also, if unevenness occurs when scraping the surface layer 920 of the existing backfill soil (expandable ground) 920, it is adjusted by the thickness of the newly installed crushed stone 93.

[0029] Next, the newly laid crushed stone 93 is compacted and leveled, and the base plates 2 are laid on top of the leveled crushed stone 93. Then, the sealant 11 is placed in the gap where the rising wall 4 and the base plates 2 meet.

[0030] Then, a spacer block is placed on the upper surface (on the convex portion when viewed from above) of the recess 21 on the other side (upper surface) of the base plate 2, and the reinforcing bar 31 is positioned at a certain distance above the upper surface of the recess 21 by this spacer block. After that, ready-mix concrete is poured onto the base plate 2 to flatten the surface of the concrete layer 3.

[0031] In the above example, the corrugated plate described above was used as the base plate 2, but it is not limited to this. As shown in Figure 5, the base plate 2 may also be a plate member 15 in which a plurality of rectangular members 15b are fixed at intervals to one side of a flat plate-shaped surface material 15a. This plate member 15 becomes a base plate 2 having alternating recesses 21 and protrusions 22 on one side (the bottom side).

[0032] Although embodiments of this invention have been described above with reference to the drawings, this invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiments within the same scope as this invention, or within the equivalent scope. [Explanation of Symbols]

[0033] 1: Earthen floor structure 2: Base plate 3: Concrete layer 4: Waist wall (upper part of a wall-like structure) 5: Underground beam 8: Earthen floor 9: Ground 11: Sealant 12: Insulation 13: Support member 15: Plate component (base plate) 15a: Flat surface material 15b: Square-shaped member 21: Recess 22: Convex part 31: Reinforcement bars 51: Leveling concrete section 52: Crushed stone layer 91: Local release 92: Backfill soil 93: Crushed stone 920: Surface layer 930: Crushed stone (to be removed)

Claims

1. A floor structure characterized by comprising a base plate having alternating recesses and protrusions on at least one side, with the one side facing the ground and the protrusions in contact with the ground, and a concrete layer constructed on the other side which becomes the upper side of the base plate.

2. The floor structure according to claim 1, characterized in that the base plate is a corrugated plate having alternating recesses and protrusions on one side and the other side.

3. The floor structure according to claim 1, wherein the base plate is a plate member in which a plurality of rectangular timber-shaped members are fixed to one side of a flat plate-shaped surface material at intervals from each other.

4. The floor slab structure according to claim 1, characterized in that an insulating material is provided in the space formed by the ground and the recess of the base plate.

5. The floor slab structure according to claim 4, characterized in that the insulation material has the property of shrinking when subjected to pressure, thereby reducing its volume.

6. The floor slab structure according to claim 1, characterized in that a support member for supporting the base plate is arranged in the space formed by the ground and the recess of the base plate.

7. The floor slab structure according to claim 6, characterized in that the support member has the property of shrinking when subjected to pressure, thereby reducing its volume.

8. The floor slab structure according to claim 1, comprising an underground beam arranged inside the ground, and a wall-like rising section installed on the underground beam, the upper side of which protrudes above the ground, wherein a sealing material is placed at the boundary between the edge of the base plate and the wall-like rising section.

9. A method for constructing a floor structure, comprising repairing a floor that has been uplifted due to expansive ground to construct the floor structure described in claim 1, The process involves dismantling and removing the raised earthen floor, The process involves removing the soil excavated from the surface layer of the above-mentioned ground, and leveling the upper surface of this ground. The process involves placing the base plate on the flattened ground, with one side of which the recess and protrusion are formed facing the ground and the protrusion in contact with the ground, The process involves placing a sealant at the boundary between the existing wall-like rising section and the base plate, The process involves creating the concrete layer on the other side that will be the upper side of the base plate, A method for constructing an earthen floor structure, characterized by including the following:

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