JP2000144762A - Foundation forming method for building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit to easily carry out the pile foundation forming work, inground beam forming work, or to easily and accurately perform excavation work for foundation forming portion and also to enhance the positional accuracy for the foundation. SOLUTION: By using the pile main bars 2x, which is provided in the pile foundation forming portion, as the main bars for a column, concrete is placed in the pile foundation forming portion without providing a base reinforcement at the bottom portion of the pile foundation forming portion. Then, concrete is placed in the inground beam forming portion and the foundation of the building is formed in a state where the inground beam body structure is held and retained in such a manner that the bottom of the inground beam body structure distributed in the inground beam forming portion is separated oppositely from the bottom surface of the inground beam forming portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a foundation such as a pile foundation of a building.

[0002]

2. Description of the Related Art A conventional construction process for forming a foundation of a building including, for example, a pile foundation and an underground beam continuous with the pile foundation will be described with reference to FIGS. I do. First, the positions of the piles and underground beams that constitute the foundation of the building are determined. Next, as shown in FIG. 9, the cast-in-place concrete pile 2 is created at a plurality of pile positions by a pile driver. This is, as is well known, drilling a hole 2s in the ground with a pile driver,
It is created by placing the main reinforcing bar 2a therein and casting concrete. The upper portion of the hole 2s is backfilled 2f. Further, in this case, in order to maintain the quality of the pile head 2t, concrete is laid at the pile head portion, and as will be described later, the extra concrete portion 2b is attached. Next, as shown in FIG. 10 and FIG. 13, the footing portion of the pile foundation portion and the ground at the position where the underground beam portion continuous with the footing portion is formed are excavated, and the footing portion forming portion 3 and the underground beam are excavated. The part forming part 4 is formed. And
As described above, the excess concrete portion 2b of the pile head is removed, and the footing portion forming portion 3 and the underground beam portion forming portion 4 are removed.
A thin concrete layer 5 (abandoned concrete) is provided on the bottom surface (see FIGS. 11 and 13). On the thin concrete layer 5 provided on the bottom surface of the footing portion forming portion 3, the footing portion and the columnar ink-out are performed, and on the thin concrete layer 5 provided on the bottom surface of the underground beam portion forming portion 4. Marking of the underground beam is performed. Next, the footing portion forming portion 3
In FIG. 12, as shown in FIG. 12, a base reinforcing bar 6 is provided on the thin concrete layer 5, a column reinforcing bar 7 is attached to a pile main reinforcing bar 2a of a pile head 2t, and in accordance with black ink of a footing portion. Then, the formwork 8 is installed so as to surround the periphery of the base reinforcing bar 6. Also, in the underground beam forming part 4, FIG.
As shown in FIG. 7, an underground beam reinforcing bar 9 (or a scaffold) is installed on the thin concrete layer 5 and the underground beam structure 10 is arranged using the underground beam reinforcing bar 9. And assemble. Then, form frames are installed on both sides of the assembled underground beam structure 10 in accordance with the ink of the underground beam portion. In FIG. 14,
Reference numeral 11 denotes a temporary passage, and reference numeral 12 denotes a temporary elevating stair. These are temporary objects for assembling the underground beam structure 10. And concrete is poured into each of the above-mentioned formwork, and a footing part and an underground beam part of a pile foundation part are created. afterwards,
While removing or assembling each formwork, backfill the soil around the completed footing and on both sides of the underground beam. Finally, a thin concrete layer or a gravel layer is provided on the ground surface, and reinforcement is arranged thereon, and then floor (soil) concrete is poured.

[0003]

However, according to the above-mentioned conventional method of forming a foundation for a building, a base reinforcing bar must be provided at the bottom in the footing portion forming portion of the pile foundation forming portion. In addition, in the underground beam part formation part, while providing a thin concrete layer at the bottom in advance,
The underground beams have to be temporarily assembled to assemble the underground beams by temporarily installing underground beam reinforcing bars, temporary passages, temporary elevating stairs, and the like, and the work is complicated. Conventionally, a certain standard is determined around the construction position of a building, and the center position of the pile, the position of the footing portion forming portion, and the position of the underground beam portion forming portion are drawn out with a thread or the like based on this standard. . However, since black ink cannot be applied on the ground 1, excavation work of a foundation forming part such as a footing part forming part and an underground beam part forming part could not be performed accurately. In addition, black ink is not applied on the ground 1, and the above-mentioned yarn may be removed or misaligned at the time of actual pile driving or construction of the footing portion or the underground beam portion. When constructing foundations and underground beams,
The work had to be performed while checking the center position of the pile, the footing, and the position of the foundation such as the underground beam, and there was a possibility that an error would occur at each check. Therefore, in addition to the above-mentioned problem, there has been a problem that the excavation work of the foundation forming portion cannot be performed accurately, and it is difficult to improve the positional accuracy of the position where the foundation is provided.

[0004] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it possible to easily perform a pile foundation portion forming operation and an underground beam portion forming operation. Another object of the present invention is to enable the excavation work of a foundation forming part to be performed accurately and easily, and to increase the positional accuracy of a position where a foundation is provided.

[0005]

According to a first aspect of the present invention, there is provided a method for forming a foundation of a building, comprising the steps of: excavating a ground to form a pile foundation and an underground beam as a foundation of the building. The pile foundation formation part and the underground beam formation part which is continuous with this pile foundation part formation part are formed, and concrete is poured into these pile foundation part formation part and the underground beam formation part, In the method of creating, by using the pile main reinforcement provided in the pile foundation portion forming part as the main reinforcement of the column,
Without providing base reinforcement at the bottom of the pile foundation part,
The concrete is poured into the pile foundation portion forming portion, and the underground beam structure disposed in the underground beam portion forming portion is separated from the underground beam forming portion so that the bottom of the underground beam structure is separated from the bottom surface of the underground beam forming portion. In a state where the beam structure was suspended via the ground surface covering layer, concrete was poured into the underground beam forming portion to form the foundation of the building. According to the second aspect of the present invention, a foundation is formed by excavating the ground to form a pile foundation forming part for forming a pile foundation as a foundation of a building, and casting concrete into the pile foundation forming part. In the method of creating a foundation for an object, the underground beam structure is disposed such that a bottom of the underground beam structure disposed in the underground beam portion forming portion is separated from a bottom surface of the underground beam forming portion. In a state of being suspended through the ground surface coating layer, concrete was poured into the underground beam forming portion to form a foundation of the building. According to a third aspect of the present invention, a foundation is formed by excavating the ground to form a pile foundation portion for forming a pile foundation portion as a foundation of a building, and casting concrete into the pile foundation portion forming portion. In the method of creating a foundation for a product, by using a pile main reinforcement provided in the pile foundation portion forming part as a main reinforcement of a column, a base reinforcement is not provided at the bottom of the pile foundation part forming part, and the pile foundation part is not provided. Concrete was poured into the formation and the foundation of the building was created. According to a fourth aspect of the present invention, in the first, second, and third aspects, the pile foundation portion forming portion and the underground beam portion forming portion exclude the ground surface corresponding to the pile foundation portion forming portion and the underground beam portion forming portion. After a ground surface coating layer made of concrete or the like is provided on the ground surface in advance, the ground where the ground surface coating layer is not provided is excavated to form the ground. According to a fifth aspect of the present invention, in the fourth aspect, the pile foundation forming portion and the underground beam forming portion are formed after at least the ground corresponding to the pile foundation forming portion and the underground beam forming portion is improved. I did it.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.
The method of making the foundation of a building by using is explained in detail. Note that FIG.
The same components as those described in the related art of FIG. 14 to FIG. 14 are denoted by the same reference numerals.

First, in a ground 1 on which a building is to be erected, a pile foundation portion for forming a pile foundation portion and an underground beam portion as a foundation of the building, and an underground beam continuous with the pile foundation portion forming portion Concrete (abandoned concrete) is cast on the ground surface excluding the ground surface corresponding to the part forming portion to provide a ground surface coating layer. Specifically, as shown in FIG. 1, first, the entire ground 1 on which a building is to be erected is excavated (root cut) by several tens of mm by the thickness of the concrete to be cast. still,
In this case, if the ground 1 has independence, it is not necessary to perform the ground improvement. However, if the ground 1 has no independence, the ground improvement of the entire ground is performed in advance. Rolling to harden the ground, or mixing cement-based or lime-based materials with the ground soil to harden the ground.) For example, if the ground 1 is the “Kanto loam layer”, it is often unnecessary to perform ground improvement. Then, the positions of the pile and the underground beam are determined. For this positioning, a certain reference is determined, and the center position of the pile, the position of the footing portion forming portion, and the position of the underground beam portion forming portion are drawn out with a thread or the like based on this reference. The above-mentioned positioning is performed on the ground surface 1A excavated by several tens of millimeters, by taking a diameter D2 larger than the pile diameter D1 around the center position where the pile is provided, to position the footing portion forming portion, and based on this position. The mold 8A is set. Further, the width W2 of the underground beam is larger than the width W1 of the underground beam on both sides of the position where the underground beam is installed, the underground beam portion forming portion is located, and the formwork 8B is installed based on this position ( Therefore, finally, a footing portion having a diameter D2 and an underground beam portion having a width W2 are created. Form 8 as described above
After installing the A and 8B, as shown in FIG.
Concrete is cast outside of A and 8B to provide a ground surface coating layer 13. That is, after slightly excavating the entire ground 1 on which the building is to be erected, on the ground surface 1A after the excavation, as shown in FIG. Formwork 8A, 8B is installed so as to divide the ground surface 1A corresponding to the beam forming portion, and the ground surface 1A excluding the ground surface corresponding to the pile foundation forming portion and the underground beam forming portion. A ground surface covering layer 13 is provided by casting concrete on the top. After providing the ground surface coating layer 13, the reference line X is moved onto the ground surface coating layer 13. That is, as shown in FIG. 2, the reference line X is measured on the ground surface covering layer 13 near the pile foundation portion forming portion and the underground beam portion forming portion as measured from a certain reference. Thereafter, the actual construction work of the pile foundation and the underground beam is performed while confirming the position based on the reference line X struck on the ground surface covering layer 13. Also, the reference line X
In this way, blackout of pillar and wall positions is also performed.

Next, as shown in FIGS. 3 and 5, a portion of the ground where the ground surface covering layer 13 is not provided is moved along the ground surface covering layer 13 along with a piling machine 30 such as an earth auger.
And the ground with the excavator 40 such as a backhoe
By excavating substantially perpendicular to A, a pile foundation portion forming portion 23 and an underground beam portion forming portion 24 are formed.

As a procedure, first, as shown in FIG.
The pile base forming part 23 is formed by the pile driving machine 30. In this case, first, a footing portion forming portion 23B is formed by drilling with a drill having a diameter D2, and then the pile position is reconfirmed based on the reference line X. Then, the pile forming portion 23A is replaced with a drill having a diameter D1. Form. Next, as shown in FIG. 4, a plurality of pile main reinforcements 2 are provided in the pile formation portion 23 </ b> A of the pile foundation portion formation portion 23.
A pile structure formed by winding x (rebar) with a band (hoop) is placed, and concrete is cast to form a pile 2 (in the case of pile head processing, the main pile 2x may be joined). .
In addition, when casting concrete in the pile formation part 23A,
It is difficult to stop the casting of concrete at the boundary between the pile forming portion 23A and the footing portion forming portion 23B, and since there is no necessity, the thin concrete layer 5 ( (Abandoned concrete). In addition, the extra concrete of the pile head 2t is not performed (when muddy water is used, the pile head concrete is removed by vacuum or the like). Furthermore, even if dry soil and the like are dislodged from the inner surface ground 23s of the footing portion forming portion 23B and accumulate on the bottom surface, the footing portion forming portion does not mix with the concrete poured into the footing portion forming portion 23B. On the inner surface (both the inner side surface and the bottom surface or at least the inner side surface) side of 23B, as an edge cutting member 14 for cutting the edge between the inner surface of the footing portion forming portion 23B and the concrete cast into the footing portion forming portion 23B. Attach a sheet, etc.

Next, as shown in FIG. 5, after forming an underground beam forming portion 24 with an excavator 40, as shown in FIG.
An underground girder structure 10A of a ground structure previously assembled with the underground beam main reinforcement 10a and the stirrup 10b (for example, an underground beam created by assembling the main reinforcement and the stirrup directly on the ground at or near the site) Beam)
Is installed in the formed underground beam portion forming portion 24. In this case, as shown in detail in FIG. 7, the underground beams of the ground structure are supported by supporting reinforcing bars 16 (Kansashi bars) which are bridged on both sides of the upper edge of the underground beam portion forming portion 3 via spacers 15, 15. Structure 10A
The underground beam structure 10A of the ground is suspended so that the bottom of the underground beam portion is separated from the bottom surface of the underground beam portion forming portion 24. In addition, a sheet or the like as the edge cutting member 14 similar to the above is attached to the inner surface side of the underground beam portion forming portion 24. When the above-mentioned formwork 8B is attached as it is, the trimming material 14 is attached to the wood 8 by the formwork 8B.
It may be nailed with b or the like, or when the form 8B is removed, it may be nailed with concrete nails or the like.

Thereafter, as shown in FIG. 4, a band 2y (hoop) is wound around the main pile 2x projecting from the pile head 2t. At this time, base reinforcement is not performed. When the RC column is to be erected, the lower end of the original column bar (not shown) is abutted to the upper end of the main pile bar 2x and connected by welding or the like. That is, structurally, the pile head 2t is considered as a foundation and a pillar, and the pile main reinforcement 2
x is directly connected to the column bar, so that the main pile bar 2x also serves as the column bar. That is, the main pile 2x planted at the pile head 2t is used as the main reinforcement of the pillar. When standing a steel column, use anchor bolts 2z
(FIG. 8) is disposed so as to protrude longer than the ground surface coating layer 13.

When the above steps are completed, as shown in FIG. 8, the main reinforcing bars 10a of the underground beam structure 10A are connected to each other by the reinforcing bars 10c. In this case, the main reinforcing bar 10a of the underground beam structure 10A and the reinforcing bar 10c connecting the main reinforcing bar 10a are connected by using a joint member 10d or by lap joint, welding, pressure welding, or the like. In addition, rebar 1
0c and the main pile 2x are not connected.

Thereafter, concrete is laid in the footing portion forming portion 23B and the underground beam portion forming portion 24 by arranging reinforcing bars (soil arranging) on the ground surface covering layer 13, thereby forming the footing portion and the ground. An underground beam is formed, and a foundation consisting of a pile foundation and an underground beam is created. Finally, cast concrete on the floor (soil) (note that
The concrete of the footing part, the underground beam part, and the floor (soil) may be simultaneously poured.

According to the first embodiment, the following effects can be obtained. (1) Since the main reinforcing bar 2x itself is used as a column bar in the reinforcing bar of the footing portion, it is not necessary to provide a base reinforcing bar. That is, conventionally, the pile main reinforcement 2a
Since the column reinforcing bar 7 is provided separately, the base reinforcing bar is provided to receive the load applied by the column reinforcing bar 7. However, in the first embodiment, the load applied to the original column reinforcing bar is Since the pile main bar 2x that is connected to the column bar and functions as a column bar is directly received, there is no need to provide a base bar arrangement. Therefore,
In the arrangement of the footing portion, the labor required for the construction can be greatly reduced as compared with the conventional case. (2) In creating the underground beam, support the preformed underground beam structure 10A so that the bottom of the underground beam structure 10A of the ground is separated from the bottom of the underground beam forming portion 24. Since it is only suspended by the reinforcing bar 16 (Kansashi bar), there is no need to install an underground beam reinforcing stand (or a scaffold), a temporary passage, and a temporary up-and-down staircase as in the related art.
There is no need to hit concrete on the bottom of the building. Therefore, in the creation of the underground beam part, the construction labor can be greatly reduced as compared with the related art. (3) Footing part forming part 23 of pile foundation forming part 23
In the excavation work of the foundation forming portion such as the B or the underground beam forming portion 24, the ground in the portion where the ground surface covering layer 13 is not provided is excavated substantially perpendicularly to the ground surface 1A along the ground surface covering layer 13. It is easy and accurate. In addition, the foundation forming portions such as the footing portion forming portion 23B and the underground beam forming portion 24 of the formed pile foundation portion forming portion 23 function as a formwork as they are, and it is not necessary to perform backfilling work. The work becomes easier. In this case, if the ground 1 has autonomy, the foundation forming portion such as the footing portion forming portion 23B and the underground beam portion forming portion 24 can function as a mold without any improvement of the ground. Also, even if the ground 1 has no independence,
By previously performing the ground improvement of the entire ground, it is possible to make the foundation forming parts such as the footing part forming part 23B and the underground beam part forming part 24 function as they are as the formwork. (4) The reference line X can be moved onto the ground surface covering layer 13, and thereafter, based on the transferred reference line X, the center position of the pile, the footing, and the position of the underground beam are accurately confirmed. Since the construction can be performed, the positional accuracy of the foundation, such as a pile, a footing, or an underground beam, can be improved as compared with the conventional method. Further, the position of the underground beam structure 10A can be determined in advance based on the reference line X so that the position of the underground beam main bar 10a does not interfere with the pile main bar 2x. There is no need to repeatedly determine the position of the underground beam structure 10A. Similarly, since the positions of the columns and walls can be accurately confirmed based on the reference line X, the positional accuracy of the positions of the columns and walls can be increased. (5) Since the edge cutting material 14 is provided on the inner surface side of the footing portion forming portion 23B and the underground beam portion forming portion 24, concrete is cast, so that the footing portion forming portion 23B and the underground beam portion forming. Since concrete and earth and sand to be poured into the portion 24 do not mix, a high-quality footing portion and underground beam portion can be created.

In the first embodiment, the method of providing the ground surface covering layer in advance has been described. However, even when the ground surface covering layer is not provided, the work of forming the pile foundation and the underground beam as the foundation can be easily performed. Can be. In addition, without providing the ground surface covering layer, the footing of the pile foundation was created by installing base reinforcement and column reinforcement as in the past, and the ground In such a state that the underground beam structure is suspended via the ground surface covering layer so that the bottom of the underground beam structure provided in the center beam forming portion is separated from the bottom surface of the underground beam forming portion. Even when the method of placing concrete in the underground beam portion forming portion is performed, the underground beam portion can be easily created as compared with the conventional method. Contrary to the above, without providing the ground surface coating layer, only in the preparation of the footing portion of the pile foundation portion, as in Embodiment 1, the main reinforcement of the pile provided in the pile foundation portion forming portion is replaced with the main reinforcement of the column. By using as, without providing the base reinforcement at the bottom of the pile foundation part forming part,
Even when the method of placing concrete in the pile foundation portion forming part is performed, the creation of the pile foundation portion can be made easier as compared with the conventional method. Further, the ground surface covering layer 13 may be formed of asphalt or the like. In short, the ground surface covering layer 13 is used for excavation work of a foundation forming part such as a footing forming part 23B or an underground beam forming part 24 of a pile foundation forming part 23. Alternatively, any other material may be used as long as it can be distinguished from the ground and can be used as a mark, or can be shifted and printed with the reference line X. Also, in the first embodiment, it has been described that if the ground 1 does not have independence, the ground improvement of the entire ground is performed in advance, but at least the foundations such as the footing portion forming portion 23B and the underground beam forming portion 24 are formed. After improving the ground of the part corresponding to the formation part,
The ground surface covering layer 13 may be provided on the ground surface excluding the ground surface corresponding to the foundation forming portion. For example, as shown by the dashed line in FIG. 5, the ground is improved only in a portion where the ground does not collapse and is less than the stable angle A, or
Considering the workability, the ground improvement may be performed only within the range of the broken line B. The same applies to the footing portion forming portion 23B. Furthermore, as the edge cutting material 14,
In addition to the sheet, such as a veneer or a keystone plate, the key is the footing forming portion 23B and the underground beam forming portion 2
Any material can be used as long as it cuts the edge between the inner surface side of 4 and the concrete cast in the footing forming portion 23B and the underground beam portion forming portion 24. Further, in the first embodiment, the underground beam structure is grounded. However, for example, after the underground beam structure is assembled by using a temporary horse or the like, the supporting reinforcing bar 16 is formed.
(Kansashi muscle). Further, the present application can be applied even when a PC pile, a steel pipe pile, or the like is used. In the first embodiment, the case where the pillars and the footing portions of the round pillar are formed has been described, but these shapes can be arbitrarily designed.

[0016]

According to the first aspect of the present invention, it is not necessary to provide a base reinforcing bar at the bottom in the footing portion forming portion of the pile foundation portion forming portion, and the bottom portion is formed in the underground beam portion forming portion. It is not necessary to perform the work of placing a thin concrete layer on the ground and the complicated work of assembling the underground beam by temporarily installing the underground beam reinforced cradles, temporary passages, temporary elevating stairs, etc. The work of making the pile foundation and underground beam can be easily performed. According to the second aspect, in the underground beam portion forming portion, the work of casting a thin concrete layer on the bottom, the temporary installation of the underground beam reinforcing bar support, the temporary passage, the temporary elevating stairs, etc., to assemble the underground beam. Since it is not necessary to perform a simple operation, the operation of forming the underground beam as a foundation can be facilitated as compared with the related art. According to the third aspect, since the base reinforcing bar does not need to be provided at the bottom in the footing portion forming portion of the pile foundation portion forming portion, the work of creating the pile foundation portion as the foundation can be facilitated as compared with the related art. According to claim 4,
In addition to the effects of the first, second, and third aspects, in the excavation work of the pile foundation portion forming portion and the underground beam portion forming portion, the ground where the ground surface covering layer is not provided is excavated along the ground surface covering layer. By simply doing, it can be done easily and accurately, and the pile foundation part forming part, underground beam part forming part functions as a formwork as it is, and it is not necessary to perform backfilling work,
The work becomes easier than before. In addition, the reference line can be moved onto the ground surface coating layer, and based on this transferred reference line, the construction can be performed while checking the position of the foundation accurately. In addition, it is possible to increase the positional accuracy of a position where a foundation is provided such as an underground beam. According to the fifth aspect, even if the ground is a ground without independence, the pile foundation part forming part and the underground beam part forming part can function as they are as the formwork. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a process chart for explaining a method for creating a foundation of a building according to a first embodiment of the present invention.

FIG. 2 is a process chart for explaining a method of forming a foundation of a building according to the first embodiment of the present invention.

FIG. 3 is a process chart for explaining a method of creating a foundation of a building according to the first embodiment of the present invention.

FIG. 4 is a process chart for explaining a method for creating a foundation of a building according to the first embodiment of the present invention.

FIG. 5 is a process chart for explaining a method of creating a foundation of a building according to the first embodiment of the present invention.

FIG. 6 is a process chart for explaining a method of creating a foundation of a building according to the first embodiment of the present invention.

FIG. 7 is a diagram showing details of FIG. 6;

FIG. 8 is a process chart for explaining a method of creating a building foundation according to the first embodiment of the present invention.

FIG. 9 is a process chart for explaining an example of a conventional method of creating a foundation of a building.

FIG. 10 is a process chart for explaining an example of a conventional method of creating a foundation of a building.

FIG. 11 is a process chart for explaining an example of a conventional method of creating a foundation of a building.

FIG. 12 is a process chart for explaining an example of a conventional method for creating a foundation of a building.

FIG. 13 is a process chart for explaining an example of a conventional method of creating a foundation of a building.

FIG. 14 is a process chart for explaining an example of a conventional method for creating a foundation of a building.

[Explanation of symbols]

1 ground, 2x pile main bar, 10A underground beam, 23 pile foundation part (foundation part), 23A pile formation part (foundation part), 23B footing part formation part (foundation part), 24 underground beam part Forming part (base forming part), 1A Ground surface excluding the ground surface corresponding to the base forming part, 13 Ground surface coating layer.

Claims (5)

[Claims] 1. A pile foundation forming part for excavating the ground to form a pile foundation and an underground beam as a foundation of a building, and an underground beam forming part continuous with the pile foundation forming part. Forming a part, and placing concrete in the pile foundation part forming part and the underground beam part forming part to form a foundation of the building. By using as a base, without providing a base reinforcing bar at the bottom of the pile foundation portion forming portion, concrete is poured into the pile foundation portion forming portion, and an underground While holding the underground beam structure, concrete is poured into the underground beam forming portion to create a foundation for the building so that the bottom of the beam structure is separated from the bottom surface of the underground beam forming portion. Of a building characterized by How to create. 2. A pile foundation portion for excavating the ground to form a pile foundation portion and an underground beam portion as a foundation of a building, and an underground beam portion continuous with the pile foundation portion forming portion. Forming a part, and placing concrete in the pile foundation part forming part and the underground beam forming part to create a foundation of the building; While holding the underground beam structure so that the bottom of the structure is separated from the bottom surface of the underground beam forming part, concrete is poured into the underground beam forming part to form the foundation of the building. A method of creating a foundation for a building, characterized in that: 3. Excavating the ground to form a pile foundation forming portion for forming a pile foundation as a foundation of a building;
In the method of casting concrete on the pile foundation portion forming part to create a foundation of a building, the pile main reinforcing bar provided on the pile foundation forming portion is used as the main reinforcing bar of the column, thereby forming the pile foundation forming portion. A method for producing a foundation for a building, wherein concrete is poured into the portion where the pile foundation is formed without forming a base reinforcing bar at the bottom to create a foundation for the building. 4. The pile foundation portion and the underground beam portion are formed on the ground surface excluding the ground surface corresponding to the pile foundation portion and the underground beam portion by a concrete surface or the like in advance. 4. The building according to claim 1, wherein, after the covering layer is provided, a portion of the ground where the ground surface covering layer is not provided is formed by excavation. 5. How to create a foundation for 5. The pile foundation forming part and the underground beam forming part are formed after at least the ground corresponding to the pile foundation forming part and the underground beam forming part is improved. A method for creating a foundation for a building according to claim 4.