Building's foundation structure

Abstract

To provide a foundation structure of a building capable of reducing the amount of excavated soil, improving workability, and achieving structural rationalization by using both steel frame foundation beams and reinforced concrete foundation beams when a low floor section and a high floor section coexist on a first floor.SOLUTION: The present invention relates to a foundation structure of a building that constitutes different floor levels of a low floor part and a high floor part in a first floor part of the building. The low floor part includes a low floor part foundation footing 12 provided at a pile head of a low floor part foundation pile 11 driven into the ground, and a reinforced concrete foundation beam 13 connecting the low floor part foundation footing 12. The high floor part comprises a high floor part foundation footing 22 provided at a pile head of a high floor part foundation pile 21 driven into the ground, and a steel frame foundation beam 23 that connects column bases of the steel frame columns 1 erected at the high floor part foundation footing position. A steel frame foundation beam 23 of the high floor part is connected to the steel frame column 1 erected at the low floor part foundation footing position at the boundary position between the reinforced concrete foundation beam position and the steel frame foundation beam position.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a foundation structure of a building that can reduce the amount of excavated soil, improve workability, and achieve structural rationalization by using a steel frame foundation beam and a reinforced concrete foundation beam together when constructing a foundation for a building where different floor levels coexist.

Background Art

[0002] For the foundation beam of a steel frame building, considering that the foundation beam contacts the soil, reinforced concrete is usually used from the perspective of durability. When constructing a reinforced concrete foundation beam, it is necessary to excavate to the lower surface level of the foundation beam and install formwork and arrange steel bars.

[0003] By the way, for example, when planning a logistics warehouse or the like and providing a truck berth, there may be a height difference at the floor level of the first floor. In such a building, when using a reinforced concrete foundation beam, it is necessary to excavate the high floor part to the same level as the low floor part in order to install the formwork and arrange steel bars of the foundation beam.

[0004] Patent Document 1 discloses a high-floor steel frame foundation beam structure that is applied to a high-floor structure where the floor level of a logistics center or the like is set to be approximately the same level as the loading platform of a conveying means such as a truck to facilitate the loading and unloading of goods. Compared with a conventional reinforced concrete foundation beam (underground beam), it does not require earthwork, concrete placement work, etc., has a short construction period, low construction cost, and is durable against external forces such as earthquakes.

[0005] This elevated steel-frame foundation beam structure specifically includes foundation piles driven into the ground, a cylindrical steel thin-sheet permanent formwork (pile cap) larger in outer diameter than the foundation piles fixed to the pile heads of the foundation piles with concrete and steel cages, anchor bolts fixed by the concrete within the cylindrical steel thin-sheet permanent formwork, and a steel frame with a base plate fixed to the lower end. The base plate and the anchor bolts are fastened, and the steel-frame foundation beam is directly connected to the steel frame so as to be positioned at a level of a predetermined height above the ground.

[0006] Further, Patent Document 2 discloses a building foundation beam structure suitable for cases where the vertical width of the clearance formed between the ground surface and the foundation beam changes, such as when the ground surface is undulating or when the foundation beams are arranged in steps. It is a building foundation structure provided with a foundation footing installed at the pile head of a pile buried in the ground. The foundation footing is composed of a steel pipe part erected on the ground surface so as to cover the pile head and filled with concrete inside, and a steel-frame beam part in which a column part built above the pile head is installed and penetratively joined to the upper end part of the steel pipe part. As a pile cap, a building foundation structure is disclosed that includes a plurality of non-standard pile caps with different lengths of the steel pipe parts.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] The elevated steel-frame foundation beam structure described in Patent Document 1 is a structure in which a pile cap is installed on the pile head to form an elevated steel-frame foundation beam when the floor level is approximately the same as the loading platform of a truck or the like. However, it does not consider a building in which a low-floor part and a high-floor part coexist.

[0009] On the other hand, the building foundation structure described in Patent Document 2 is directed to the case where the vertical width of the clearance formed between the ground surface and the foundation beam changes, and in the combination of the pile cap and the steel frame foundation beam, the lengths of the steel pipe parts as the pile caps are made different. However, it is not suitable for cases where the low floor part is at a height close to the planned ground surface. That is, it is difficult to take rust prevention measures in the low floor part, and in adjusting the length of the pile cap, there are problems such as difficulty in achieving a structural balance between the low floor part and the high floor part.

[0010] The present invention aims to solve the problems in the prior art as described above. When constructing the foundation of a building where different floor levels coexist, by using a steel frame foundation beam and a reinforced concrete foundation beam in combination, the amount of excavated soil can be reduced, the constructability can be improved, and a building foundation structure capable of achieving structural rationalization is provided.

Means for Solving the Problems

[0011] The present invention is a building foundation structure that constitutes different floor levels of a low floor part and a high floor part in the first floor part of a building. The low floor part includes a low floor part foundation footing provided at the pile head of a low floor part foundation pile driven into the ground, and a reinforced concrete foundation beam connecting the low floor part foundation footings. The high floor part includes a high floor part foundation footing provided at the pile head of a high floor part foundation pile driven into the ground, and a steel frame foundation beam connecting the column foot parts of the columns erected at the high floor part foundation footing positions. The steel frame foundation beam of the high floor part is connected to the column erected at the low floor part foundation footing position at the boundary position between the reinforced concrete foundation beam position and the steel frame foundation beam position.

[0012] For example, in the planning of a logistics warehouse or the like, when different floor levels such as a low floor part and a high floor part occur due to the planning of a truck berth or the like, the low floor part with a large part in contact with the soil is not suitable for steel frames, and since it is necessary to smoothly transmit the seismic force from the ground, the low floor part has a structure using a reinforced concrete foundation beam. On the other hand, by adopting a structure using a steel frame foundation beam for the high floor part, it becomes unnecessary to excavate the high floor part over a wide area, and the formwork and steel bar arrangement of the foundation beam of the high floor part become unnecessary.

[0013] In particular, when the low floor part is a low floor close to the design ground surface, the reinforced concrete foundation beam is superior in terms of durability against moisture, and is also advantageous in terms of suppressing floor cracks.

[0014] In the foundation structure of the building of the present invention, the low floor part foundation footing and the high floor part foundation footing can be made of reinforced concrete. For example, for the high floor part foundation footing, a structure in which a steel pile cap is arranged on the pile head and filled with concrete may be adopted as in the inventions described in Patent Document 1 or Patent Document 2 mentioned above.

[0015] The foundation structure of the building of the present invention is suitable for the case where the upper structure is a steel frame structure, but is not necessarily limited to the steel frame structure, and may be a reinforced concrete structure, a wooden structure, etc., and can also be applied to a building combining these.

[0016] In the foundation structure of the building of the present invention, as a rust prevention measure for the steel frame foundation beam of the high floor part, for example, by providing ventilation means such as a ventilation device at the position of the steel frame foundation beam, it is possible to lower the relative humidity in the pit.

Effects of the Invention

[0017] The foundation structure of the building of the present invention is configured as described above. When different floor levels such as a low floor part and a high floor part occur, the low floor part with a large contact area with the soil is structured with a reinforced concrete foundation beam, so that the seismic force from the ground can be smoothly transmitted, and effects such as durability and suppression of floor cracks can be obtained. Also, rust prevention measures like those for steel beams are not necessary.

[0018] On the other hand, the high floor part is structured with a steel foundation beam, so that it is not necessary to excavate the high floor part over a wide area, and reduction of labor, reduction of construction waste, and shortening of the process can be achieved by reducing formwork work and steel bar placement work.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0020] Hereinafter, the present invention will be described based on the attached drawings. FIG. 1 is a vertical sectional view showing an embodiment of the foundation structure of the building of the present invention, and FIGS. 2, 3, and 4 are enlarged views of part A, part B, and part C thereof, respectively.

[0021] In this embodiment, as shown in part A of FIG. 1 and FIG. 2, the foundation structure of the low floor part is provided with a low floor part foundation footing 12 on the pile head of the low floor part foundation pile 11 driven into the ground. This low floor part foundation footing 12 is made of reinforced concrete from the perspective of durability.

[0022] Also, in this example, a reinforced concrete foundation column 2 is provided on top of the low floor foundation footing 12, and a steel column 1 is provided via an anchor material 4. The column footings composed of the low floor foundation footing 12 and the reinforced concrete foundation column 2 are connected by a reinforced concrete foundation beam 13 which is a low floor foundation beam, and a low floor slab 14 is laid on the reinforced concrete foundation beam 13.

[0023] Since the low floor part is in contact with the soil in many parts and may be a floor close to the design ground surface, by using a reinforced concrete foundation beam with excellent durability against moisture, the effect of suppressing floor cracks can also be obtained. Also, the seismic force from the ground can be smoothly transmitted by the reinforced concrete foundation beam 13.

[0024] As shown in part B of FIG. 1 and FIG. 3, for the foundation structure of the high floor part, a high floor foundation footing 22 is provided at the pile head of the high floor foundation pile 21 driven into the ground. The high floor foundation footing 22 can be made of reinforced concrete, but it may also have a structure where a steel pile cap is placed on the pile head and filled with concrete.

[0025] At the position of the high floor foundation footing 22, a steel column 1 is erected via an anchor material 4, the column footings of the steel column 1 are connected by a high floor foundation beam (steel foundation beam) 23, and a high floor slab 24 is laid on the high floor foundation beam 23.

[0026] By using the steel foundation beam 23 for the high floor part, it is not necessary to extensively excavate the high floor part, and the labor for formwork and steel reinforcement can also be saved. Also, between the high floor foundation beam 23 of the high floor part and the ground, by filling with the excavated soil 3 generated during construction, material and cost rationalization can be achieved.

[0027] In this embodiment, as shown in part C of FIG. 1 and FIG. 4, for the foundation structure at the boundary position between the low floor part and the high floor part, similar to the foundation structure of the low floor part, a low floor foundation footing 12 and a reinforced concrete foundation column 2 are provided at the pile head of the low floor foundation pile 11, and a steel column 1 is erected.

[0028] Connect the low-floor foundation beam 13 to the position of the low-floor foundation footing 12, and bolt-join the high-floor foundation beam (steel frame foundation beam) 23 to the bracket 26 provided at the column base of the steel column 1 erected on the low-floor foundation footing 12 through the splice plate 25, thereby forming different floor levels between the low-floor part and the high-floor part.

[0029] Figure 5 is an enlarged view showing the boundary position between the reinforced concrete foundation beam position and the steel frame foundation beam position in an embodiment different from that of Figure 1. In Figures 1 and 4, the case where the steel column 1 is at the boundary position between the low-floor part and the high-floor part is shown, but the boundary position between the low-floor part and the high-floor part and the column position do not necessarily have to be the same. Figure 5 shows the case where there is no steel column 1 at the boundary position between the low-floor part and the high-floor part.

[0030] Similar to Figures 2 and 4, a low-floor foundation footing 12 and a reinforced concrete foundation column 2 are provided at the pile head of the low-floor foundation pile 11, and the steel column 1 is erected. A low-floor foundation beam (reinforced concrete foundation beam) 13 is connected to the position of this low-floor foundation footing 12, a bracket 26 is provided at the column base of the steel column 1 erected on the low-floor foundation footing 12, and the high-floor foundation beam (steel frame foundation beam) 23 is bolt-joined through the splice plate 25.

[0031] As shown in Figure 5, the low-floor slab 14 is laid up to the position of the end of the low-floor foundation beam 13, and different floor levels between the low-floor part and the high-floor part are formed as the boundary position between the high-floor part and the low-floor part. The laying range of the low-floor slab 14 can be designed within the range where this low-floor foundation beam 13 is provided.

[0032] In this embodiment, the steel column 1 is used, but the superstructure of the building is not necessarily limited to the steel frame structure.

Explanation of Reference Numerals

[0033] 1... Steel column 2... Reinforced concrete foundation column 3... Excavated soil 4... Anchor material 11... Low-floor foundation pile 12... Low-floor foundation footing 13… Low bed foundation beam (reinforced concrete foundation beam) 14… Low bed slab 21… High bed foundation pile 22… High bed foundation footing 23… High bed foundation beam (steel frame foundation beam) 24… High bed slab 25… Splice plate 26… Bracket

Claims

1. A building foundation structure that forms different floor levels of a low floor part and a high floor part in the first floor part of a building, wherein the low floor part includes a low floor part foundation footing provided on the pile head of a low floor part foundation pile driven into the ground, and a reinforced concrete foundation beam connecting the low floor part foundation footings; the high floor part includes a high floor part foundation footing provided on the pile head of a high floor part foundation pile driven into the ground, and a steel frame foundation beam connecting the column feet of columns erected at the position of the high floor part foundation footing; and a column erected at the position of the low floor part foundation footing at the boundary position between the position of the reinforced concrete foundation beam and the position of the steel frame foundation beam is connected to the steel frame foundation beam of the high floor part. A building foundation structure characterized by this.

2. In the building foundation structure according to Claim 1, the low floor part foundation footing and the high floor part foundation footing are made of reinforced concrete. A building foundation structure characterized by this.

3. In the building foundation structure according to Claim 1 or 2, the upper structure of the building is a steel frame structure. A building foundation structure characterized by this.

4. In the building foundation structure according to any one of Claims 1 to 3, ventilation means is provided at the position of the steel frame foundation beam of the high floor part. A building foundation structure characterized by this.

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