How to design the foundation structure of a detached building

Abstract

To provide a method for designing the foundation structure of a detached building, which enables the design of the foundation structure of a detached building having a column foundation at low cost and in a short time.SOLUTION: A outer peripheral underground beam 30A is provided at a bottom of an outer wall of a detached building. Inside the outer peripheral underground beam 30A, a solid foundation portion 20 having a slab foundation main reinforcement structural portion having a plurality of main reinforcements intersecting each other in the horizontal direction is formed. Along the lower part of the internal bearing wall of a detached building and the part between the slab foundation main bar structures adjacent to each other, an internal underground beam 30B that forms the slab foundation portion 20 in a plurality of sections is formed endlessly. The slab foundation portion 20 has a maximum size of one section of 4550 mm or less in each of the vertical and horizontal directions. A columnar foundation structure 40 is formed at least at the lower part of the column of the detached building and along the internal underground beam 30 at an interval of 1820 mm or less. When the distance between the columnar foundation structures 40 adjacent to each other is 910 mm or more, a floor bundle is formed in an intermediate portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for designing a foundation structure of a detached building having a columnar foundation structure. [Background technology]

[0002] Conventionally, as a building foundation supporting the base of a detached building, including a wooden structure, a building foundation having, for example, a rising wall portion, a continuous footing, and a slab footing formed between the rising wall portion and the continuous footing has been widely used. In such detached buildings, moisture tends to accumulate under the floor, so there is a great demand for technology to improve the efficiency of the air cycle under the floor. On the other hand, various techniques have been disclosed for improving the air cycle efficiency of detached buildings (see, for example, Patent Document 1).

[0003] However, even if the technology described in Patent Document 1 improves the air cycle between the floor space and the attic in a detached building, the floor space, where moisture and the like tend to accumulate, only has openings formed in the slab, so the improvement in air cycle efficiency is limited, and it is difficult to significantly improve the air cycle efficiency under the floor space.

[0004] In response to this, for example, a column foundation (columnar foundation structure), which is a cylindrical independent foundation, has been disclosed as a technology applicable to improving the efficiency of the air cycle by reducing the size of the walls of a slab or the like erected under a floor (see, for example, Patent Document 2). The column foundation is placed over a linearly extending underground beam, and includes, for example, a main bar of a column rising vertically, and a cylindrical concrete section covering the main bar.

[0005] Traditionally, when designing foundation structures, including column foundations for detached buildings, the foundation structure has been designed individually for each detached building being constructed, depending on the bearing capacity of the ground, the weight of the building, the layout of the building, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Jpn. Jpn. Published No. 63-040570 [Patent Document 2] Japanese Patent Application Publication No. 11-043951 Summary of the Invention [Problem to be solved by the invention]

[0007] However, with the conventional foundation structure design method, in which the placement of column foundations was individually designed for each detached building being constructed, the design of the foundation structure took time and money, resulting in increased construction costs.

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a method for designing the foundation structure of a detached building, which makes it possible to design the foundation structure of a detached building having a column foundation at low cost and in a short period of time. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention proposes the following means. That is, the design method of the foundation structure of the detached building of the present invention is for a wooden structure of 2 stories or less, a maximum height of 13 m or less, a maximum eaves height of 9 m or less, a floor height of 2.4 m to 3.0 m, and a bearing capacity of 20 kN / m 2 A design method for a foundation structure of a detached building using a cylindrical foundation structure erected on a slab foundation, which is applicable to the above-mentioned detached building, includes providing an outer periphery underground beam at the bottom of the exterior wall of the detached building, forming a slab foundation main reinforcement structural part having a plurality of main reinforcements crossing each other along the horizontal direction on the inside of the outer periphery underground beam, forming an endless internal underground beam along the bottom of the internal load-bearing wall of the detached building and between the adjacent slab foundation main reinforcement structural parts, which divides the slab foundation into a plurality of sections, and making the maximum size of each section of the slab foundation be 4550 mm or less in both length and width, and forming the cylindrical foundation structure. teeth, at least The detached buildingFormed at intervals of 1820 mm or less along the bottom of the pillar and the internal underground beam Be When the interval between the adjacent cylindrical foundation structures is 910 mm or more, a floor beam is formed in the middle portion, and the cylindrical foundation structure further formed on the mat foundation portion is , directly under and in front of the base The floor area of ​​the first floor of the detached building is 16.0 m 2 below It can bear floor loads in the range of The present invention is characterized in that the electrodes are arranged as follows. Effect of the Invention

[0012] According to the present invention, a method for designing the foundation structure of a detached building can be provided, which makes it possible to design the foundation structure of a detached building having a column foundation at low cost in a short period of time. [Brief description of the drawings]

[0013] [Figure 1] This is an oblique view illustrating the state in which the foundation is installed on the building foundation. [Diagram 2] This is an oblique view explaining the general configuration of installing a foundation on a building foundation. [Diagram 3] FIG. 2 is a plan view for explaining an outline of a building foundation. [Figure 4] FIG. 4 is a diagram for explaining a schematic configuration of the building foundation, and is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 2 is a schematic plan view showing the arrangement of each part based on the design method for the foundation structure of a detached building of the present invention. [Figure 6] FIG. 1 is an explanatory diagram showing an example of division of a slab foundation (floor slab) by internal underground beams. [Figure 7] FIG. 1 is an explanatory diagram showing an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a method for designing a foundation structure of a detached building according to one embodiment of the present invention will be described with reference to the drawings. Each embodiment shown below is specifically described to better understand the gist of the invention, and does not limit the present invention unless otherwise specified. In addition, the drawings used in the following description may show essential parts enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as the actual ones.

[0015] First, a schematic configuration of a building foundation including a columnar foundation structure formed by the molded member for columnar foundation structures of the present invention will be described. FIG. 1 is a perspective view illustrating a state in which a base is installed on a building foundation, and FIG. 2 is a perspective view illustrating a schematic configuration of the building foundation. The building foundation 1 comprises a rising wall portion 10 erected around a detached building (not shown), such as a two-story house, a slab foundation portion 20, an underground beam 30, a column base (columnar foundation structure) 40, and a floor beam 60. In addition, the concrete portions constituting the rising wall portion 10, the slab foundation portion 20, the underground beams 30, and the column base 40 are integrally formed.

[0016] The foundation 2 of a detached building (not shown) is placed on the rising wall portion 10, and the pillars (not shown) of the detached building are erected. In addition, the foundation 2 and the pillars (not shown) are erected between the column bases 40 formed on the underground beams 30 as appropriate. In addition, floor beams 60 are provided below the base 2 and below the beams 6 as necessary.

[0017] Fig. 3 is a plan view showing a schematic configuration of the building foundation, and Fig. 4 is a cross-sectional view explaining the schematic configuration shown in the arrow IV-IV view in Fig. 3. For convenience, Figs. 3 and 4 show a part of Figs. 1 and 2 in a simplified form.

[0018] The rising wall portion 10 is erected corresponding to, for example, the outer wall periphery (outer periphery) of a detached building, and is formed around a mat foundation portion 20. The rising wall portion 10 includes a rising wall portion main reinforcement 11 and a rising wall portion concrete portion 15.

[0019] The rising wall main reinforcement 11 has a rising portion 11A and an anchoring portion 11B, and the anchoring portion 11B is buried in the slab foundation portion 20. The rising wall concrete portion 15 is formed so as to cover the rising portion 11A.

[0020] The slab foundation section (slab floor) 20 is formed, for example, in the inner area surrounded by the rising wall section 10, and includes a slab foundation main reinforcement structure section 22 and a slab foundation concrete section 25.

[0021] The slab foundation main reinforcement structure 22 comprises a plurality of main reinforcements 22X arranged horizontally along the long side (first direction: X direction) of the rising wall portion 10, and a plurality of main reinforcements 22Y formed along the short side (second direction: Y direction) perpendicular to the direction in which the main reinforcements 22X are arranged. The slab foundation concrete portion 25 has a thickness of, for example, about 200 mm, and is formed so as to cover the slab foundation main reinforcement structural portion 22 .

[0022] The underground beams 30 are composed of an outer periphery underground beam 30A arranged under the rising wall portion 10, and an inner underground beam 30B formed in the inner area surrounded by the outer periphery underground beam 30A so as to overlap with the mat foundation portion 20. Such an underground beam 30 has a higher rigidity than the mat foundation portion 20. Moreover, the internal underground beams 30B are formed along the long sides (first direction: X direction) or short sides (second direction: Y direction) of the rising wall portion 10.

[0023] In this embodiment, the internal underground beam 30B includes an underground beam main reinforcement structural portion 31, a diamond bar reinforcement portion (reinforcement structural portion) 34, and an underground beam concrete portion 35. The underground beam main reinforcement structure 31 includes, for example, a plurality of underground beam main reinforcements 32 and a plurality of stirrups (hoops) 33.

[0024] The multiple underground beam main reinforcements 32 are formed, for example, along the long or short sides of the rising wall portion 10, and are configured so that two (multiple) underground beam main reinforcements 32 extending in parallel and arranged horizontally are arranged in two sets (multiple) in the vertical direction.

[0025] In addition, the underground beam main reinforcements 32 arranged above and below are configured to be surrounded by stirrups (hoops) 33, for example, to connect the underground beam main reinforcements 32 in the vertical direction. In addition, the underground beam main reinforcements 32 arranged above and below may be connected on three sides, the left, right and bottom, to connect the underground beam main reinforcements 32 in the vertical direction.

[0026] In addition, in this embodiment, the diaphragm reinforcement portion 34 is formed below the position where the column base 40 is installed on the underground beam 30. The diamond reinforcement section 34, for example, includes two (multiple) first reinforcement bars 34A that extend parallel to the underground beam main reinforcement section 32 at a crossing angle of 45°, sandwiching the underground beam main reinforcement section 31, and two (multiple) second reinforcement bars 34B that extend parallel to the underground beam main reinforcement section 32 in a direction symmetrical to the first reinforcement bar 34A and the underground beam main reinforcement section 31, i.e., in a direction perpendicular to the first reinforcement bar 34A, sandwiching the underground beam main reinforcement section 31.

[0027] The underground beam concrete portion 35 is formed to cover the underground beam main reinforcement structural portion 31, and has a vertical thickness of, for example, about 300 mm, which is thicker than the slab foundation concrete portion 25.

[0028] (Columnar foundation structure molding components) Next, the layout design of the column base (columnar foundation structure) based on the design method of the foundation structure of a detached building of the present invention will be described. The following are examples of detached buildings to which the design method for the foundation structure of a detached building of the present invention can be applied. (1) Structure: Wooden (conventional frame construction method) (2) Building use: Detached house (3) Number of floors: 2 floors (4) Maximum height: 13m or less (5) Maximum eave height: 9m or less (6) Floor height: 2.4m~3.0m (7) Earth bearing capacity: 20kN / m 2 End

[0029] First, when designing, the bearing capacity of the land on which the two-story wooden detached building is to be constructed is confirmed. For example, a soil survey, such as a Swedish sounding test, is conducted to determine that the bearing capacity of the land is 20 kN / m 2 It is necessary that the bearing capacity of the soil is 20kN / m or more. 2 If it is less than this, additional ground improvement and reinforcement work will be required.

[0030] Next, the positions of the columns and bearing walls of the detached building to be constructed are confirmed from the design drawings. For bearing walls, the wall volume calculation and balance check are to be carried out based on Article 46 of the Enforcement Order of the Building Standards Act. The positions of the columns and bearing walls confirmed here will be referenced when designing the layout of the column base (columnar foundation structure) described below.

[0031] FIG. 5 is a schematic plan view showing the layout of each part based on the design method of the foundation structure of a detached building of the present invention. [Layout of outer foundation, internal underground beams and slabs] (1) The outer perimeter underground beams 30A are placed on the outer perimeter of the building. (2-1) The internal underground beam 30B must be placed under the internal load-bearing wall W1. (2-2) The internal underground beams 30B are placed on the lines dividing the slab foundation portion (slab floor) 20. (2-3) Both ends of the internal underground beam 30B are arranged to contact the outer periphery underground beam 30A or other internal underground beams 30B, making the internal underground beam 30B endless. (3) The size of the slab foundation portion (slab floor) 20 of one section surrounded by the outer underground beams 30A and the inner underground beams 30B shall be such that the maximum dimensions are 4,550 mm or less in both length and width. If the size of the slab foundation portion (slab floor) 20 of one section exceeds 4,550 mm in both length and width, an internal underground beam 30B is provided to divide the slab foundation portion (slab floor) 20 into two or more sections. FIG. 6 shows an example of division of such a mat foundation portion (slab floor) 20 by internal underground beams 30B.

[0032] [Column-based placement] (1) A column base (columnar foundation structure) 40 is placed directly below the column P1. (2) The column base 40 is basically placed on the internal underground beam 30B. However, the column base 40 that satisfies the following conditions (2-1) and (2-2) may be placed on the mat foundation portion (slab floor) 20. (2-1) A column base 40 located off the line of the internal underground beam 30B. (2-2) Directly below when there are columns only on the first floor, or directly below when there are no columns and only the first floor load is borne (foundation and joists). In this case, the first floor floor area borne by the column base 40 is 16.0 m 2 For example, if the floor size of the area is 3.64m x 3.185m, the floor area is 11.6m. 2 = 16.0m 2 Since it fits within this range, the column base 40 can be installed. (3) The column bases 40 are formed at intervals of 1820 mm or less along at least the lower part of the pillars P1 of the detached building and the internal underground beams 30B. When the interval between adjacent column bases 40 is 910 mm or more, a floor beam 60 (see FIG. 1) is formed in the middle part.

[0033] Based on the above-described design method for the foundation structure of a detached building of the present invention, by placing the outer perimeter foundation, internal underground beams, and slab floor, and then placing the column base, it is no longer necessary to design the column base placement each time according to the structure of each individual detached building, as was done in the past. Therefore, it is possible to provide a method for designing the foundation structure of a detached building, which enables the design of the foundation structure of a detached building having a column foundation at low cost and in a short period of time. EXAMPLES

[0034] FIG. 7 shows an example of a column base arrangement designed based on the design method for the foundation structure of a detached building of the present invention. According to this embodiment, the placement position of the column base can be easily set in accordance with the above-mentioned design rules simply by identifying the outer perimeter underground beams 30A, the interior underground beams 30B, the slab foundation portion (slab floor) 20, etc. based on the floor plan of the detached building.

[0035] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0036] 1 Architectural foundations 2. Foundation 3 Pillars 6. Pullout 7 Joists 10. Rising wall 11 Main reinforcement of rising wall 11A Rising section 11B Fixing section 15 Concrete section of rising wall 20 Flat foundation (slab floor) 22 Slab foundation main reinforcement structure 25 Concrete foundation 30 Underground beam 30A Perimeter underground beam 30B Internal underground beam 31 Underground beam main reinforcement structure 32 Underground beam main reinforcement 33 Stirrup (stitching) 34 Diamond reinforcement section (reinforcement structure section) 35 Underground beam concrete section 40 Column base (columnar foundation structure)

Claims

[Claim 1] Wooden construction with 2 stories or less, maximum height 13 m or less, maximum eave height 9 m or less, floor height 2.4 m or more and 3.0 m or less, soil bearing capacity 20 kN / m ２ A method for designing a foundation structure of a detached building using a cylindrical foundation structure erected on a slab foundation, which is applied to the above detached building, A periphery underground beam is provided at the lower part of the exterior wall of the detached building, A mat foundation portion is formed on the inside of the outer periphery underground beam, the mat foundation portion being provided with a slab foundation main reinforcement structure portion having a plurality of main reinforcements crossing each other along a horizontal direction, An internal underground beam is formed endlessly along the lower part of the internal load-bearing wall of the detached building and between the adjacent slab foundation main reinforcement structural parts, forming the slab foundation part into a plurality of sections; The maximum size of each section of the mat foundation is 4,550 mm or less in both length and width, The cylindrical foundation structure is formed at least along the lower part of the column of the detached building and the internal underground beam at intervals of 1820 mm or less, When the interval between the adjacent cylindrical foundation structures is 910 mm or more, a floor beam is formed in the middle portion, The cylindrical foundation structure further formed on the slab foundation is directly under the foundation and is 16.0 m2 of the floor area of ​​the first floor of the detached building. ２ A method for designing the foundation structure of a detached building, characterized in that the foundation structure is arranged to bear the following range of floor loads.

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