Foundation and foundation construction method

Abstract

To provide a foundation and a foundation construction method which can be constructed more easily and with higher strength than conventional methods.SOLUTION: A foundation 1 is provided on the ground on which a structure is to be installed, and supports the structure. The foundation 1 includes a rising portion 10, a first side base portion 21, a second side base portion 22, and a reinforcing bar 30. The rising portion 10 includes a bottom wall portion 13, a first side wall portion 14, a second side wall portion 15, and poured concrete 12. A first through hole 14a and a second through hole 15a are formed in the first side wall portion 14 and the second side wall portion 15, respectively. The reinforcing bar 30 is inserted into the first through hole 14a and the second through hole 15a and is disposed so as to straddle the rising portion 10 and the first side base portion 21 and the second side base portion 22. The poured concrete 12 connects the rising portion 10 to the first side base portion 21 and the second side base portion 22.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a foundation and a foundation construction method, and particularly to a foundation provided on the ground for installing a structure and supporting the structure, and a foundation construction method.

Background Art

[0002] Conventionally, when constructing a foundation, it has been known to use a U-shaped groove block for a side ditch as a formwork for cast-in-place concrete. For example, Patent Document 1 discloses that when constructing a foundation of a structure, reinforcing bars are arranged inside a U-shaped groove block which is a concrete secondary product, concrete is cast inside the U-shaped groove block, and a foundation in which the U-shaped groove block and the concrete are integrated is constructed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when constructing a mat foundation that supports a building as a foundation of a structure, a formwork for forming a rising portion and a base formwork for forming a footing are arranged on the ground, and concrete is cast into each formwork to construct the mat foundation. However, since the configuration of the formwork becomes complicated, there is a risk of reduced workability. In addition, when a U-shaped groove block such as that in Patent Document 1 is used as a formwork to form a rising portion, it is necessary to place concrete that will become side base portions on both sides of the U-shaped groove block to form a footing. Therefore, there was a risk that the concrete placed inside the U-shaped groove block and the concrete of the side base portions would not be connected to each other, resulting in a decrease in the strength of the footing. Also, it was not possible to connect the reinforcing bars placed inside the U-shaped groove block and the reinforcing bars placed in the side base portions, which could lead to a decrease in the strength of the footing.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a foundation and a foundation construction method that can be constructed more easily and with higher strength than in the past.

Means for Solving the Problems

[0006] According to the foundation of the present invention, the above problems are solved by a foundation provided on the ground where a structure is installed and supporting the structure, the foundation including a rising portion that extends horizontally along the structure and rises upward from the ground, a first side base portion and a second side base portion that extend along the extending direction of the rising portion and are provided on both sides in the width direction of the rising portion, and reinforcing bars that extend along the width direction of the rising portion and are arranged so as to straddle the rising portion, the first side base portion, and the second side base portion. The rising portion has a bottom wall portion disposed on the ground, a first side wall portion and a second side wall portion that rise from both end portions of the bottom wall portion in the width direction, and placed concrete that is placed in an inner region formed by the bottom wall portion, the first side wall portion, and the second side wall portion. Openings penetrating in the width direction are respectively formed in the first side wall portion and the second side wall portion. The reinforcing bars are arranged so as to straddle the rising portion, the first side base portion, and the second side base portion in a state of being inserted through the openings. The placed concrete is placed at least inside the inner region and the openings, and the rising portion is connected to the first side base portion and the second side base portion.

[0007] With the above configuration, since the openings are provided in the first side wall portion and the second side wall portion, the reinforcing bars can be arranged so as to straddle the rising portion and the side base portion. Further, through the openings, the placed concrete in the rising portion can be connected to each side base portion. Therefore, the foundation can be constructed more easily and with higher strength than before.

[0008] At this time, at least a part of each of the first side base portion and the second side base portion may be composed of the placed concrete and integrated with the placed concrete in the rising portion through the opening. With the above configuration, the concrete placed in the inner region formed by the bottom wall portion, the first side wall portion, and the second side wall portion flows out from the opening, and each side base portion is formed by the concrete flowing out from the opening. Therefore, the rising portion and each side base portion are integrated, and the strength of the foundation can be further improved.

[0009] At this time, a plurality of the openings may be provided in each of the first side wall portion and the second side wall portion. With the above configuration, by providing a plurality of openings, while maintaining the strength of each side wall portion, the concrete in the opening increases, so that the strength of the foundation can be further improved.

[0010] At this time, the reinforcing bar has a base bar that extends in the width direction of the rising portion and is inserted into the opening, and a stirrup bar that extends in the height direction of the rising portion and is arranged in the inner region. The foundation includes a first spacer that is attached to the base bar and arranged in the inner region, and a second spacer that is attached to the stirrup bar and arranged in the inner region. The first spacer holds the height position of the base bar, and the second spacer holds the position of the stirrup bar in the width direction of the rising portion. With the above configuration, when placing concrete inside the rising portion, the position of the reinforcing bar can be held. Therefore, the reinforcing bar can be arranged at an appropriate position.

[0011] Further, according to the foundation construction method of the present invention, the problem is a method of constructing a foundation that is provided on the ground where a structure is installed and supports the structure, including: an arranging step of arranging a bottom wall portion that horizontally extends along the structure, a first side wall portion and a second side wall portion that rise from both ends in the width direction of the bottom wall portion on the ground; a reinforcing bar arranging step of arranging reinforcing bars that extend along the width direction of the bottom wall portion; a formwork arranging step of arranging a base formwork that extends along the extending direction of the bottom wall portion at intervals on both sides of the first side wall portion and the second side wall portion in the width direction of the bottom wall portion; and a placing step of placing cast-in-place concrete in a state where the reinforcing bars are arranged. In the reinforcing bar arranging step, the reinforcing bars are inserted through openings formed in the first side wall portion and the second side wall portion and penetrating in the width direction, and the reinforcing bars are arranged so as to straddle the inner region formed by the bottom wall portion, the first side wall portion, and the second side wall portion and the inside of the base formwork. In the placing step, the cast-in-place concrete is placed in the inner region and the openings to form a rising portion composed of the bottom wall portion, the first side wall portion, and the second side wall portion, and the cast-in-place concrete is placed inside the base formwork to form a first side base portion and a second side base portion, thereby solving the problem. With the above configuration, by inserting the reinforcing bars through the openings formed in the first side wall portion and the second side wall portion, the reinforcing bars can be arranged so as to straddle the rising portion and the side base portions. Further, by placing the cast-in-place concrete in the openings, the cast-in-place concrete of the rising portion can be connected to each side base portion. Therefore, the foundation can be constructed more easily and with higher strength than before.

[0012] At this time, in the placing step, it is preferable to integrate the rising portion with the first side base portion and the second side base portion by placing the cast-in-place concrete from the inner region through the openings into the inside of the base formwork. With the above configuration, the concrete placed in the inner region formed by the bottom wall portion, the first side wall portion, and the second side wall portion flows out from the opening, and each side base portion is formed by the concrete flowing out from the opening. Therefore, the rising portion and each side base portion are integrated, and the strength of the foundation can be further improved.

[0013] At this time, in the steel bar arrangement step, the base bars extending in the width direction are inserted into the opening, the first spacers are attached to the base bars in the inner region, the stirrup bars extending in the height direction of the rising portion are arranged in the inner region, the second spacers are attached to the stirrup bars, and in the placing step, the height position of the base bars is held by the first spacers, and the placing concrete is placed in a state where the position of the stirrup bars in the width direction of the rising portion is held by the second spacers. With the above configuration, when placing concrete inside the rising portion, the position of the steel bars can be held. Therefore, the steel bars can be arranged at appropriate positions.

Advantages of the Invention

[0014] According to the foundation and the foundation construction method of the present invention, construction can be carried out more easily and with higher strength than before.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0016] Hereinafter, based on FIGS. 1 to 6, the foundation 1 of an embodiment of the present invention (hereinafter, this embodiment) will be described. In the following description, as indicated by the arrows shown in FIG. 1, the “height direction” means the vertical direction of the foundation 1 provided on the ground. The “extending direction” is a direction that horizontally extends along the structure and means the front-rear direction of the foundation 1. Further, the “width direction” is the width direction of the foundation 1 and means the left-right direction of the foundation 1. Note that the “width direction” is a direction orthogonal to each of the “height direction” and the “extending direction”. In the “extending direction”, with the foundation 1 as the center, the front side is the “front side” and the rear side is the “rear side”. Also, in the “width direction”, with the foundation 1 as the center, the left side is the “left side” and the right side is the “right side”.

[0017] <Foundation> The foundation 1 is provided on the ground where the structure is installed and supports the structure. Specifically, the foundation 1 is a strip foundation buried in the ground where the building is installed, horizontally extends along the building, and has an inverted T-shaped cross section. The foundation 1 mainly includes a rising portion that extends vertically and serves as an underground beam supporting the building, and a footing portion that extends in the width direction and is buried in the ground to serve as a base. Note that the foundation 1 is not limited to a strip foundation and may be a mat foundation or an isolated foundation. Further, the structure supported by the foundation 1 may be a structure other than a building.

[0018] As shown in FIGS. 1 and 2, the foundation 1 includes a rising portion 10 that horizontally extends along the structure and rises upward from the ground, a pair of left and right side base portions 20 that extend along the extending direction of the rising portion 10 and are provided on both sides in the width direction of the rising portion 10, reinforcing bars 30 that extend along the width direction of the rising portion 10 and are arranged to straddle the rising portion 10 and the side base portions 20, and spacers 40 that hold the positions of the reinforcing bars 30. The footing portion of the foundation 1 is composed of a lower portion 10a of the rising portion 10 and a side base portion 20. The footing portion is provided on crushed stone S laid on the excavated ground. In other words, the rising portion 10 is provided on the crushed stone S, and concrete is placed on both sides of the lower portion 10a of the rising portion 10, thereby forming the foundation 1.

[0019] <Rising portion> As shown in FIG. 1, the rising portion 10 horizontally extends in the front-rear direction along the building and is a portion that rises upward from the ground while being partially embedded in the ground. The rising portion 10 extends in the vertical direction and serves as an underground beam that supports the building. The rising portion 10 includes a U-shaped groove block 11 that is a concrete secondary product and placed concrete 12 placed inside the U-shaped groove block 11. The rising portion 10 is formed by placing the placed concrete 12 inside the U-shaped groove block 11 provided on the crushed stone S. In other words, the rising portion 10 is composed of a U-shaped groove block 11 that is a concrete secondary product and the placed concrete 12. The lower portion 10a of the rising portion 10 constitutes the footing portion together with the side base portion 20, and the upper portion 10b constitutes the rising portion.

[0020] As shown in FIG. 2, the U-shaped groove block 11 is a concrete secondary product with an open upper end and a U-shaped cross section. The U-shaped groove block 11 is used as a formwork for forming the rising portion 10. By using the U-shaped groove block 11, which is a concrete secondary product, as a formwork and making the U-shaped groove block 11 a part of the foundation 1, the installation of the formwork can be facilitated and the workability can be improved. If the entire U-shaped groove block 11 is made of concrete, it is easy to manufacture and the strength can be improved. However, this is not the only case. As long as the U-shaped groove block 11 can maintain its strength, it is not necessary for the entire U-shaped groove block 11 to be made of concrete.

[0021] As shown in FIGS. 2 and 3, the U-shaped groove block 11 has a bottom wall portion 13 disposed on the ground, and a first side wall portion 14 and a second side wall portion 15 rising from both ends in the width direction of the bottom wall portion 13. Specifically, a first side wall portion 14 extending upward is provided at the left end of the bottom wall portion 13. Also, a second side wall portion 15 extending upward is provided at the right end of the bottom wall portion 13.

[0022] As shown in FIG. 1, the rising portion 10 is composed of a U-shaped groove block 11 consisting of a bottom wall portion 13, a first side wall portion 14, and a second side wall portion 15, and a placed concrete 12 placed inside the U-shaped groove block 11. Note that the U-shaped groove block 11 may be integrally formed of concrete for the bottom wall portion 13, the first side wall portion 14, and the second side wall portion 15, but may also be configured as separate bodies. Also, the shape of the U-shaped groove block 11 is not limited to a U-shaped cross-section, and any shape that can be filled with concrete inside is acceptable. Further, the U-shaped groove block 11 may be provided with a lid at the upper opening, or may be provided with an opening for pouring concrete laterally.

[0023] As shown in FIG. 2, the bottom wall portion 13 is a plate-shaped concrete that extends horizontally along the structure (building) and is long in the front-rear direction, and is the portion placed above the crushed stone S. Note that a part of the bottom wall portion 13 may be open. In this case, a block spacer may be provided to form a space below the U-shaped groove block 11, and the placed concrete 12 placed inside the U-shaped groove block 11 may be allowed to flow out from the opening of the bottom wall portion 13 to below the U-shaped groove block 11 to form a central base portion connecting the side base portions 20. At this time, the left and right side base portions 20 and the central base portion constitute a footing portion, and the entire U-shaped groove block 11 constitutes a rising portion.

[0024] As shown in FIG. 2, the first side wall portion 14 and the second side wall portion 15 are concretes that rise from both ends in the width direction of the bottom wall portion 13 (the width direction of the rising portion 10) and extend in the vertical direction. The upper portions of the first side wall portion 14 and the second side wall portion 15 constitute the outer walls of the rising portions. The lower portions of the first side wall portion 14 and the second side wall portion 15 are in close contact with the side base portion 20 to constitute the footing portion.

[0025] Openings penetrating in the width direction of the bottom wall portion 13 are respectively formed in the first side wall portion 14 and the second side wall portion 15. Specifically, a plurality of first through holes 14a, which are openings penetrating in the left - right direction, are formed in the lower portion of the first side wall portion 14. Also, a plurality of second through holes 15a, which are openings penetrating in the left - right direction, are formed in the lower portion of the second side wall portion 15.

[0026] The first through holes 14a and the second through holes 15a are formed to have a hole diameter larger than the diameter of the base bars 33 described later. In other words, the first through holes 14a and the second through holes 15a are circular holes of a size that allows one base bar 33 to be inserted therethrough. Note that the openings are not limited to circular holes, and may be rectangular through - holes, or may be notches where the first side wall portion 14 and the second side wall portion 15 are cut out together with the bottom wall portion 13. Also, a plurality of base bars 33 may be inserted through the openings.

[0027] The first through holes 14a and the second through holes 15a are respectively provided in the lower portions of the first side wall portion 14 and the second side wall portion 15 that are close to the bottom wall portion 13 and in the intermediate portions above the lower portions. Also, the first through holes 14a and the second through holes 15a are formed in plurality at a predetermined interval in the extending direction (front - rear direction) of the rising portion 10.

[0028] Reinforcing bars 30 are arranged inside the U - shaped groove block 11. By placing the placing concrete 12 with the reinforcing bars 30 arranged inside the U - shaped groove block 11, the reinforcing bars 30 can be embedded in the rising portion 10. Specifically, in the inner region formed by the bottom wall portion 13, the first side wall portion 14, and the second side wall portion 15 (the inner region of the U-shaped groove block 11), main bars 31, base bars 33, and rib bars 34, which will be described later, are arranged. Further, the base bars 33 are inserted through the first through holes 14a and the second through holes 15a.

[0029] The first through holes 14a and the second through holes 15a are provided at the same height position on the left and right. By inserting the base bars 33 through the first through holes 14a and the second through holes 15a, the base bars 33 can be arranged to penetrate the U-shaped groove block 11 in the left-right direction. Due to the left and right openings, the reinforcing bars 30 can be arranged to straddle the lower part 10a of the rising part 10 and the side base part 20, so that the strength of the foundation 1 can be improved.

[0030] In this way, in the height direction and the extending direction, by providing a plurality of openings in the first side wall portion 14 and the second side wall portion 15 respectively, while maintaining the strength of the first side wall portion 14 and the second side wall portion 15, it is possible to arrange the reinforcement bars corresponding to foundations 1 of various sizes.

[0031] The placed concrete 12 is the concrete placed on-site at the construction site of the foundation 1. As shown in FIGS. 4 and 5, the placed concrete 12 is placed inside the U-shaped groove block 11. Specifically described, the placed concrete 12 includes first concrete 16 placed in the inner region of the U-shaped groove block 11 and second concrete 17 placed inside the first through holes 14a and the second through holes 15a. Also, the placed concrete 12 flows out from the first through holes 14a and the second through holes 15a to the outside of the U-shaped groove block 11 and is placed inside the base formwork F to form the side base part 20.

[0032] The first concrete 16 is the concrete that is poured from above the U-shaped groove block 11 through a hose H and placed in the inner region of the U-shaped groove block 11. The second concrete 17 is the concrete placed inside the openings (the first through hole 14a and the second through hole 15a). The second concrete 17 connects the first concrete 16 and the side base portion 20.

[0033] <Side base portion> As shown in FIG. 1, the side base portion 20 horizontally extends in the front - rear direction along the extending direction of the rising portion 10, and is continuously provided on both sides of the lower portion 10a of the rising portion 10. The side base portion 20 is formed on the crushed stone S and is buried in the ground when the construction of the foundation 1 is completed. As shown in FIG. 4, the side base portion 20 is the concrete placed inside the base formwork F and is formed by in - situ casting. As shown in FIG. 5, the side base portion 20 has a first side base portion 21 formed on the left side of the rising portion 10 and a second side base portion 22 formed on the right side of the rising portion 10.

[0034] As shown in FIG. 1, the first side base portion 21 has a rectangular cross - section and is the long concrete in the front - rear direction formed on the left side of the lower portion 10a in the rising portion 10. As shown in FIG. 4, the first side base portion 21 is formed by the placed concrete 12 flowing out from the first through hole 14a.

[0035] As shown in FIG. 1, the second side base portion 22 has a rectangular cross - section and is the long concrete in the front - rear direction formed on the right side of the lower portion 10a in the rising portion 10. The first side base portion 21 is formed by the placed concrete 12 flowing out from the second through hole 15a as shown in FIG. 4.

[0036] As shown in FIGS. 3 - 5, the side base portion 20 is formed by placing the placed concrete 12 inside the base formwork F provided in a pair on the left and right sides of the rising portion 10. In other words, the side base portion 20 is composed of the placed concrete 12 and forms a footing portion together with the lower portion 10a of the rising portion 10.

[0037] Note that the side base portion 20 may be not only the concrete placed on-site but also precast concrete products. In this case, the placed concrete 12 flowing out from the first through-hole 14a and the second through-hole 15a of the U-shaped groove block 11 may form a part of the side base portion 20. Further, the side base portion 20 does not have to be entirely formed of concrete. In this way, at least a part of each of the first side base portion 21 and the second side base portion 22 may be composed of the placed concrete 12 and integrated with the placed concrete 12 in the rising portion 10 through the opening.

[0038] As shown in FIG. 4, when the placed concrete 12 is poured into the inside of the U-shaped groove block 11 from above by the hose H, it accumulates in the inner region of the U-shaped groove block 11 and flows out from the first through-hole 14a and the second through-hole 15a to the outside of the U-shaped groove block 11.

[0039] As shown in FIG. 5, when the placement of the placed concrete 12 is completed, the first concrete 16 is placed in the inner region of the U-shaped groove block 11, and the second concrete 17 is placed inside the first through-hole 14a and the second through-hole 15a. Then, the side base portion 20 is formed by the placed concrete 12 flowing out from the first through-hole 14a and the second through-hole 15a to the outside of the U-shaped groove block 11.

[0040] In this way, the side base portion 20 is integrated with the first concrete 16 in the inner region of the U-shaped groove block 11 through the first through-hole 14a and the second through-hole 15a. In other words, the second concrete 17 provided inside the first through-hole 14a and the second through-hole 15a connects the first concrete 16 in the inner region of the U-shaped groove block 11 and the side base portion 20. Note that the placed concrete 12 only needs to be placed at least in the inner region of the U-shaped groove block 11 and inside the first through-hole 14a and the second through-hole 15a and connect the rising portion 10 with the first side base portion 21 and the second side base portion 22.

[0041] On the first side wall portion 14 and the second side wall portion 15, a plurality of openings are respectively provided in the height direction and the extending direction. By forming the plurality of openings, the amount of the placed concrete 12 flowing out from the inner region of the U-shaped groove block 11 can be increased. Therefore, since the connection area between the placed concrete 12 of the rising portion 10 and the side base portion 20 increases, the strength of the footing portion can be improved. Also, the placing time can be shortened.

[0042] Note that the side base portion 20 is formed by the placed concrete 12 flowing out from the first through hole 14a and the second through hole 15a, but is not limited thereto. For example, as shown in FIG. 4, it may be formed by the concrete poured from above the base formwork F by the hose H. Also, the concrete placed in the inner region of the U-shaped groove block 11 may be formed by the concrete poured from above the base formwork F. For example, the concrete poured from above the base formwork F may flow into the inner region of the U-shaped groove block 11 through the first through hole 14a and the second through hole 15a, and the rising portion 10 may be formed.

[0043] <Reinforcement bar> As shown in FIGS. 1 and 2, the reinforcing bar 30 extends in the width direction of the rising portion 10 (the width direction of the bottom wall portion 13) and is arranged so as to straddle the rising portion 10 and the first side base portion 21 and the second side base portion 22. The reinforcing bar 30 has a main bar 31 extending in the front-rear direction in the rising portion 10, a base auxiliary bar 32 extending in the front-rear direction in the side base portion 20, a base bar 33 extending in the left-right direction, and a stirrup bar 34 extending in the up-down direction. The main bar 31, the base auxiliary bar 32, the base bar 33, and the stirrup bar 34 are tied at their respective intersections.

[0044] The main reinforcement bars 31 extend in the front-rear direction and are arranged in the inner region of the U-groove block 11. The main reinforcement bars 31 include a lower main reinforcement bar 31a arranged in the lower part (footing part) of the U-groove block 11 and an upper main reinforcement bar 31b arranged in the upper part of the U-groove block 11. Note that stirrups may be arranged between the lower main reinforcement bar 31a and the upper main reinforcement bar 31b in the vertical direction.

[0045] The base auxiliary reinforcement bars 32 extend in the front-rear direction and are arranged inside the side base part 20. The base auxiliary reinforcement bars 32 include a left base auxiliary reinforcement bar 32a arranged in the first side base part 21 and a right base auxiliary reinforcement bar 32b arranged in the second side base part 22.

[0046] The base reinforcement bars 33 extend in the width direction of the rising part 10 and are inserted through the openings. Specifically, the base reinforcement bars 33 extend in the left-right direction, are inserted through the first through hole 14a and the second through hole 15a, and connect the lower main reinforcement bar 31a with the left base auxiliary reinforcement bar 32a and the right base auxiliary reinforcement bar 32b.

[0047] The abdominal reinforcement bars 34 extend in the height direction of the rising part 10 and are arranged in the inner region of the U-groove block 11. Specifically, the abdominal reinforcement bars 34 extend in the vertical direction and connect the lower main reinforcement bar 31a and the upper main reinforcement bar 31b in the inner region of the U-groove block 11.

[0048] As shown in FIG. 5, when the placement of the placed concrete 12 is completed, the reinforcing bars 30 are embedded in the first concrete 16, the second concrete 17, and the side base part 20. In other words, the reinforcing bars 30 are arranged so as to straddle the rising part 10, the first side base part 21, and the second side base part 22 in a state of being inserted through the first through hole 14a and the second through hole 15a.

[0049] <Spacer> As shown in Fig. 2, the spacer 40 is a member attached to the reinforcing bar 30 and for holding the reinforcing bar 30 at an appropriate position when placing. The spacer 40 is made of, for example, resin, steel, etc., and is disposed inside the U-groove block 11. The shape of the spacer 40 is, for example, disk-shaped, star-shaped, etc., and is attached so as to sandwich the reinforcing bar 30. The spacer 40 has a first spacer 41 attached to the base bar 33 and disposed in the inner region of the U-groove block 11, and a second spacer 42 attached to the web bar 34 and disposed in the inner region of the U-groove block 11.

[0050] A pair of left and right first spacers 41 are provided near the first side wall portion 14 and the second side wall portion 15 in the inner region of the U-groove block 11 and are attached to the base bar 33. The first spacer 41 holds the height position of the base bar 33. Although a pair of left and right first spacers 41 are provided, the number, position, and size are not limited as long as the base bar 33 can be held.

[0051] The second spacer 42 is provided between the first side wall portion 14 and the second side wall portion 15 and is attached to the web bar 34. The second spacer 42 holds the position (left and right position) in the width direction of the rising portion 10 of the web bar 34. The second spacer 42 is formed to a size that fits between the first side wall portion 14 and the second side wall portion 15, but a gap may be formed between the second spacer 42 and the first side wall portion 14 and the second side wall portion 15. Also, the number, position, and size of the second spacer 42 are not limited as long as the web bar 34 can be held.

[0052] As shown in Fig. 5, when the placement of the placed concrete 12 is completed, the spacer 40 is embedded in the first concrete 16. Thus, by the spacer 40, when placing the placed concrete 12 inside the rising portion 10, the position of the reinforcing bar 30 can be held. Therefore, when constructing the foundation 1, the reinforcing bar 30 can be disposed at an appropriate position inside the foundation 1.

[0053] With the above configuration, since the first through holes 14a and the second through holes 15a serving as openings are provided in the first side wall portion 14 and the second side wall portion 15, the reinforcing bars 30 can be arranged so as to straddle the rising portion 10 and the side base portion 20. Also, through the first through holes 14a and the second through holes 15a, the placed concrete 12 of the rising portion 10 can be connected to each side base portion 20. Furthermore, the rising portion 10 formed with the U-shaped groove block 11 composed of the bottom wall portion 13, the first side wall portion 14, and the second side wall portion 15 as a formwork can be configured as a part of the foundation 1.

[0054] <Construction method of foundation> Next, the construction method of the foundation 1 will be described with reference to FIG. 6. The construction method is a method of constructing the foundation 1 that is provided on the ground where the structure is installed and supports the structure. The construction method of the foundation 1 includes an "arrangement step (S1)" of arranging the U-shaped groove block 11 on the ground, a "reinforcing bar arrangement step (S2)" of arranging the reinforcing bars 30 and the spacers 40, a "formwork arrangement step (S3)" of arranging the base formwork F, a "placement step (S4)" of placing the placed concrete 12 in a state where the reinforcing bars 30 are arranged, and a "formwork removal step (S5)" of removing the base formwork F. In addition, in the construction of the foundation 1, the description of the construction steps other than the above will be omitted.

[0055] In the "arrangement step (S1)", the operator arranges on the ground the bottom wall portion 13 extending horizontally along the structure, and the first side wall portion 14 and the second side wall portion 15 rising from both ends in the width direction of the bottom wall portion 13. Specifically, as shown in FIG. 3, the operator arranges the U-shaped groove block 11 serving as the formwork of the rising portion 10 on the crushed stone S of the ground.

[0056] Subsequently, in the "steel bar placement process (S2)", the operator places the steel bars 30 extending along the width direction of the bottom wall portion 13. The operator inserts the steel bars 30 into the openings formed in the first side wall portion 14 and the second side wall portion 15 and penetrating in the width direction, and arranges the steel bars 30 so as to straddle the inner region formed by the bottom wall portion 13, the first side wall portion 14, and the second side wall portion 15 and the inside of the base formwork F. At this time, the operator inserts the base bars 33 extending in the width direction into the openings, attaches the first spacers 41 to the base bars 33 in the inner region of the U-groove block 11, arranges the web bars 34 extending in the height direction of the rising portion 10 in the inner region of the U-groove block 11, and attaches the second spacers 42 to the web bars 34.

[0057] Specifically, as shown in FIG. 3, the operator arranges the main bars 31 and the web bars 34 in the inner region of the U-groove block 11 and arranges the base auxiliary bars 32 inside the base formwork F. Further, the operator inserts the base bars 33 into the first through holes 14a and the second through holes 15a and arranges the base bars 33 so as to straddle the inner region of the U-groove block 11 and the inside of the base formwork F. The operator ties each intersection of the steel bars 30.

[0058] In addition, the operator attaches the first spacers 41 to the base bars 33 in the inner region of the U-groove block 11 and attaches the second spacers 42 to the web bars 34. Note that the order of arranging each steel bar 30 is not limited to this and can be changed as appropriate. Further, the operator may attach the spacers 40 to each steel bar 30 and then arrange the steel bars 30 and the spacers 40 inside the U-groove block 11.

[0059] Subsequently, in the "formwork placement process (S3)", the operator places the base formwork F extending along the extending direction of the bottom wall portion 13 with a space on both sides of the first side wall portion 14 and the second side wall portion 15 in the width direction of the bottom wall portion 13. Specifically, as shown in FIG. 3, the operator installs a pair of left and right base formworks F on the crushed stone S at positions spaced a predetermined distance from both side wall portions of the U-shaped groove block 11. The base formwork F is a plate-shaped member extending longitudinally in the front-rear direction and is arranged along the U-shaped groove block 11. The base formwork F is made of wood, for example, and is removed from the foundation 1 after construction.

[0060] In the "pouring step (S4)", the operator pours the placed concrete 12 into the inner region and the opening of the U-shaped groove block 11 to form a rising portion 10 composed of a bottom wall portion 13, a first side wall portion 14, and a second side wall portion 15. Further, the operator pours the placed concrete 12 inside the base formwork F to form a first side base portion 21 and a second side base portion 22. At this time, the operator pours the placed concrete 12 while the height position of the base bar 33 is held by the first spacer 41 and the position of the stirrup bar 34 in the width direction of the rising portion 10 is held by the second spacer 42.

[0061] Specifically, as shown in FIG. 4, with the reinforcing bars 30 arranged, the operator pours the placed concrete 12 into the inside of the U-shaped groove block 11 from above with a hose H. Then, the placed concrete 12 accumulates in the inner region of the U-shaped groove block 11, passes through the first through hole 14a and the second through hole 15a, and flows out of the U-shaped groove block 11. And the placed concrete 12 that has flowed out of the U-shaped groove block 11 accumulates inside the base formwork F. The operator pours the placed concrete 12 until the inside of the U-shaped groove block 11 and the inside of the base formwork F are filled. The operator can form the foundation 1 in which the reinforcing bars 30 are embedded by pouring the placed concrete 12 with the reinforcing bars 30 arranged inside the U-shaped groove block 11 and the inside of the base formwork F.

[0062] Note that the operator pours the placed concrete 12 into the inner region of the U-shaped groove block 11 from above the U-shaped groove block 11 through the hose H to form the side base portion 20, but the placed concrete 12 may also be poured from above the base formwork F through the hose H to form the side base portion 20. At this time, the operator may pour the placed concrete 12 from both above the U-shaped groove block 11 and above the base formwork F, or may pour the placed concrete 12 from only one side.

[0063] In this way, in the "pouring step (S4)", the operator pours the placed concrete 12 into the inside of the base formwork F through the opening from the inner region of the U-shaped groove block 11, thereby integrating the rising portion 10, the first side base portion 21, and the second side base portion 22. Since the rising portion 10 and the side base portion 20 are formed of integrated concrete, the strength of the foundation 1 can be further improved.

[0064] In the "formwork removal step (S5)", the operator removes the base formwork F from the foundation 1. Specifically, as shown in FIG. 5, when the placed concrete 12 placed inside the U-shaped groove block 11 and inside the base formwork F has solidified, the operator removes and removes the base formwork F from the completed foundation 1. In this way, with the reinforcing bars 30 arranged, by pouring the placed concrete 12 into the U-shaped groove block 11 and the base formwork F which are secondary concrete products, the foundation 1 with the reinforcing bars 30 embedded therein is constructed.

[0065] By inserting the reinforcing bars 30 into the first through holes 14a and the second through holes 15a formed in the first side wall portion 14 and the second side wall portion 15 through the above steps, the reinforcing bars 30 can be arranged so as to straddle the rising portion 10 and the side base portion 20. Also, by pouring the placed concrete 12 into the first through holes 14a and the second through holes 15a, the placed concrete 12 of the rising portion 10 and each side base portion 20 can be connected.

[0066] In this way, using the U-shaped groove block 11 composed of the bottom wall portion 13, the first side wall portion 14, and the second side wall portion 15 as a formwork, while forming the rising portion 10, the side base portion 20 can be formed by the placed concrete 12 flowing out from the first through hole 14a and the second through hole 15a. Therefore, it is possible to easily form the foundation 1 while improving the strength of the footing portion by closely adhering the U-shaped groove block 11 and each side base portion 20 with the placed concrete 12.

[0067] In the above embodiment, the foundation and the construction method of the foundation according to the present invention have been mainly described. However, the above embodiment is merely an example for facilitating the understanding of the present invention and does not limit the present invention. The present invention can be changed and improved without departing from its gist, and it goes without saying that equivalents of the present invention are included therein. In particular, what has been described in the above embodiment is merely an example and does not limit the present invention.

Explanation of Reference Numerals

[0068] 1 Foundation 10 Rising portion 10a Lower portion 10b Upper portion 11 U-shaped groove block 12 Placed concrete 13 Bottom wall portion 14 First side wall portion 14a First through hole (opening) 15 Second side wall portion 15a Second through hole (opening) 16 First concrete 17 Second concrete 20 Side base portion 21 First side base portion 22 Second side base portion 30 Reinforcing bar 31 Main reinforcing bar 31a Lower main reinforcing bar 31b Upper main reinforcing bar 32 Base auxiliary reinforcing bar 32a Left base auxiliary rib 32b Right base auxiliary rib 33 Base rib 34 Rib 40 Spacer 41 First spacer 42 Second spacer S Crushed stone F Base formwork H Hose

Claims

1. A foundation provided in the ground where a structure is installed and supporting the structure, comprising a rising portion that extends horizontally along the structure and rises upward from the ground, a first side base portion and a second side base portion that extend along the extending direction of the rising portion and are provided on both sides in the width direction of the rising portion, and reinforcing bars that extend along the width direction of the rising portion and are arranged so as to straddle the rising portion, the first side base portion, and the second side base portion. The rising portion has a bottom wall portion disposed on the ground, a first side wall portion and a second side wall portion that rise from both end portions in the width direction of the bottom wall portion, and placed concrete placed in an inner region formed by the bottom wall portion, the first side wall portion, and the second side wall portion. Openings penetrating in the width direction are respectively formed in the first side wall portion and the second side wall portion. The reinforcing bars are arranged so as to straddle the rising portion, the first side base portion, and the second side base portion in a state of being inserted through the openings. The placed concrete is at least placed inside the inner region and inside the openings, and connects the rising portion to the first side base portion and the second side base portion. A foundation characterized by this.

2. At least a part of each of the first side base portion and the second side base portion is composed of the placed concrete, and is integrated with the placed concrete in the rising portion through the openings. The foundation according to claim 1, characterized by this.

3. The foundation according to claim 1 or 2, characterized in that a plurality of the openings are respectively provided in the first side wall portion and the second side wall portion.

4. The reinforcing bars include base bars that extend in the width direction of the rising portion and are inserted through the openings, and web bars that extend in the height direction of the rising portion and are arranged in the inner region. The foundation includes a first spacer attached to the base bars and arranged in the inner region, and a second spacer attached to the web bars and arranged in the inner region. The first spacer holds the height position of the base bars, and the second spacer holds the position of the web bars in the width direction of the rising portion. The foundation according to claim 1 or 2, characterized by this.

5. A method for constructing a foundation provided in the ground for installing a structure and supporting the structure, comprising: an arranging step of arranging on the ground a bottom wall portion extending horizontally along the structure, a first side wall portion and a second side wall portion rising from both ends in the width direction of the bottom wall portion; a reinforcing bar arranging step of arranging reinforcing bars extending along the width direction of the bottom wall portion; a formwork arranging step of arranging a base formwork extending along the extending direction of the bottom wall portion at intervals on both sides of the first side wall portion and the second side wall portion in the width direction of the bottom wall portion; a placing step of placing placed concrete in a state where the reinforcing bars are arranged; In the reinforcing bar arranging step, the reinforcing bars are inserted into openings formed in the first side wall portion and the second side wall portion and penetrating in the width direction, and the reinforcing bars are arranged so as to straddle an inner region formed by the bottom wall portion, the first side wall portion and the second side wall portion and the inside of the base formwork; In the placing step, the placed concrete is placed in the inner region and the openings to form a rising portion composed of the bottom wall portion, the first side wall portion and the second side wall portion, characterized in that the placed concrete is placed inside the base formwork to form a first side base portion and a second side base portion.

6. In the placing step, the placed concrete is placed inside the base formwork through the opening from the inner region, so that the rising portion, the first side base portion and the second side base portion are integrated. The method for constructing a foundation according to claim 5.

7. In the reinforcing bar arranging step, a base bar extending in the width direction is inserted into the opening, and a first spacer is attached to the base bar in the inner region; a rib bar extending in the height direction of the rising portion is arranged in the inner region, and a second spacer is attached to the rib bar; In the placing step, the placed concrete is placed in a state where the height position of the base bar is held by the first spacer and the position in the width direction of the rising portion of the rib bar is held by the second spacer. The method for constructing a foundation according to claim 5 or 6.

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