Structural surface and construction method of structural surface

Abstract

To achieve a high floor ratio with a specification that requires little design and construction labor, and to obtain a horizontal structural surface that can reduce the volume of materials by using a horizontal structural surface according to the present invention.SOLUTION: A horizontal structural surface 10F is a horizontal structural surface in which a plurality of face materials 40 are fixed to a floor frame 12 of a wooden building, and it comprises a plurality of beams 20 arranged in parallel, a receiving member 30 provided at a joint portion of the face materials and perpendicular to the beams, and nails 50 for fixing four sides and an intermediate portion of the face materials to the beams or the receiving member. When the vertical and horizontal dimensions of the receiving member 30 are set to less than 90 [mm], and the nail 50 is driven at a pitch of 75 [mm] or less, a floor ratio is set to 5 times or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a horizontal structural surface used in wooden buildings and the like. [Background technology]

[0002] The Building Standards Act requires that building confirmation be obtained for wooden buildings of three stories or more, or wooden houses that exceed a specified area (500 m2) or height (height 13 m, eaves height 9 m), and therefore structural calculations are carried out when designing such wooden buildings. On the other hand, for wooden buildings two stories or less that fall below the specified area and are used for residential purposes (hereafter referred to as "general wooden buildings"), structural calculations do not need to be carried out in principle if simplified calculations of wall volume, etc. and specifications are satisfied, and this is often omitted. The Building Standards Act Enforcement Order contains provisions regarding construction specifications (framework necessary for structural strength), and it is common for each specification to be determined in accordance with these provisions when designing general wooden buildings.

[0003] The construction specifications stipulated in the Building Standards Act Enforcement Order present various types of bearing wall structures (frameworks with walls) and also indicate the strength index (so-called wall factor) according to the structural type (framework type). In other words, the wall factor indicated here is used as a reference to select the type of bearing wall required for each part of each floor when designing the entire building.

[0004] As mentioned above, the Building Standards Act Enforcement Order prescribes load-bearing walls, but does not specify "horizontal structural surfaces" such as the floor structure (hereafter referred to as "floor horizontal structural surface") or the roof structure (hereafter referred to as "roof horizontal structural surface"). Of course, for general wooden buildings, there is no need to carry out special structural calculations for the horizontal structural surfaces. In other words, in terms of the load-bearing structure of wooden buildings, load-bearing walls are given more importance than horizontal structural surfaces.

[0005] However, the horizontal structural planes also function as load-bearing structures, and when considering the strength of a wooden building as a whole, it is natural that the strength of the horizontal structural planes cannot be overlooked. The main role of the horizontal structural planes is to transmit horizontal forces, including earthquake loads, to the load-bearing walls. If the rigidity of the horizontal structural planes is low, they may deform or bend significantly, or may be damaged or destroyed before the load-bearing walls do, and in such cases the load-bearing walls cannot perform to their full potential. If the horizontal structural planes transmit horizontal forces appropriately (in other words, in a balanced manner) to the surrounding load-bearing walls, the load-bearing walls will function effectively, and as a result, the wooden building will be able to resist external forces. In other words, the rigidity, strength, and toughness (hereinafter collectively referred to as "strength") of the horizontal structural planes contribute in no small way to the strength of the wooden building as a whole, and for this reason the horizontal structural planes are also required to have a considerable strength.

[0006] Since horizontal structural surfaces affect the strength of wooden buildings, there are times when the strength of horizontal structural surfaces is actively evaluated, even for general wooden buildings. For example, housing manufacturers may emphasize that their wooden buildings are stronger than those of other companies in that they have high strength horizontal structural surfaces in addition to the bearing walls. In this case, the standard indicator of the strength of the horizontal structural surfaces of floors is the "floor ratio (here, the horizontal structural surfaces of the roof are also referred to as the "floor ratio"). The Act on Promotion of Quality Assurance of Housing (hereinafter referred to as the "Housing Quality Assurance Act") stipulates earthquake resistance grades (grades 1 to 3) as housing performance indications, and the floor ratio is one of the factors used to determine this earthquake resistance grade. The floor ratio is determined in accordance with the Japanese Housing Performance Indication Standards stipulated in the Housing Quality Assurance Act.

[0007] In addition, the strength of the horizontal structure (i.e., the floor ratio) is also important for long-lasting quality housing that is eligible for special tax treatment. Specifically, a certain earthquake resistance grade (grade 2 or higher) is required to be certified as a long-lasting quality house, which means that a sufficient floor ratio is necessary.

[0008] Alternatively, a significant floor magnification may be required for wooden buildings with three or more floors that require structural calculations for building confirmation under the Building Standards Act, or wooden houses that exceed a specified area (500 m2) or height (height 13 m, eaves height 9 m). In particular, the greater the distance between the load-bearing walls (i.e., the larger the space you want to enlarge), the higher the magnification of the horizontal structural surface is required.

[0009] In light of this, various technologies related to horizontal structural members that focus on their strength have been proposed. For example, Patent Document 1 proposes an adhesive-type horizontal structural member that can obtain a high floor multiplication factor by fixing the horizontal surface material to the beam material using both adhesive and connecting members such as nails and screws. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2019-027234 A Summary of the Invention [Problem to be solved by the invention]

[0011] As mentioned above, the floor multiplier is determined according to the Japan Housing Performance Indication Standards. Specifically, several structural types of horizontal structural surfaces are exemplified, and a floor multiplier (existing floor multiplier) is set for each structural type. In addition, although the "Allowable Stress Design of Wooden Frame Construction Houses (2017 Edition)" does not use the term "floor multiplier," it does indicate the relationship between the specifications of the horizontal structural surface and its strength (allowable shear strength per unit length). The allowable shear strength per unit length shown here can be converted to the floor multiplier by dividing it by the conversion value of 1.96 (kN / m).

[0012] The structural types (specifications) of horizontal structural surfaces listed in the Japan Housing Performance Indication Standards and the Allowable Stress Design for Wooden Frame Construction Houses (hereinafter collectively referred to as "Conventional Standards, etc.") are determined by a combination of the type of surface material, the specifications of connecting members (type and installation interval), the specifications of joists (dimensions and installation interval), and the joint specifications of the joists and beams. Therefore, when designing horizontal structural surfaces, traditionally it has been mainstream to select from structural types that combine these. However, because the structural types listed here are primarily intended to be used for general wooden buildings, there are few examples of structural types that can accommodate high floor ratios, such as a floor ratio of more than 5.

[0013] In structural types where the floor multiplier exceeds 5 times, screws, such as the well-known "Neda knot," are normally used as fastening members. When screws are used as fastening members, the structural type specifications are determined by a combination of the type of surface material, the type of screw, and the placement and spacing of the screws, so there is little impact on the type of floor framing, such as the placement of beams. Therefore, it can be said to be a relatively simple specification. In other words, when nails are used as fastening members, detailed strength calculations that include the type of floor framing are normally required, so this has the advantage of requiring less design effort.

[0014] However, when screws are used as fastening members to obtain a high floor ratio, the overall length of the screws becomes long. Therefore, these screws are fastened to the surface material while rotating, which increases the work time and labor required compared to nails that can be driven from above.

[0015] Furthermore, under conventional specifications, in order to prevent the support material from cracking due to the screws being fastened, the support material placed at the joints of the surface materials generally required a cross-section of 90 mm or more (90 mm length x 90 mm width), which poses the issue of increasing the volume of material for the horizontal structural components.

[0016] In consideration of the above, the present invention aims to provide a horizontal structural member that can achieve a high floor ratio with specifications that require little design and construction effort, and that can reduce the material volume. [Means for solving the problem]

[0017] The horizontal structural surface in the first aspect of the present invention is a horizontal structural surface in which a plurality of panel members are fixed to the floor structure of a wooden building, and comprises a plurality of beams arranged in parallel, a support member perpendicular to the beams and provided at the joints of the panel members, and nails for fixing the four sides and center of the panel members to the beams or support members, and when the length and width of the support member are set to less than 90 mm and the nails are driven in at a pitch of 75 mm or less, the floor multiplier is set to 5 times or more.

[0018] In the first mode, the horizontal structural surface is a wooden floor structure including multiple beams arranged in parallel and support members perpendicular to the beams and installed at the joints of the surface members, to which multiple panel members are fixed. The four sides and center of the horizontal structural surface are fixed to the beams or support members using connecting members, resulting in a structural form in which the floor multiplier is set to 5 times or more. This structural form allows for a high floor multiplier, but does not require detailed strength calculations, including the floor structure type, and requires little design effort.

[0019] Furthermore, by setting the pitch of the fastening members to 75 mm or less, nails can be used as fastening members, which shortens the work time and reduces the labor required for construction compared to using screws as fastening members.

[0020] Furthermore, by using nails as joining members, a structural design that achieves a high floor ratio can be achieved while the cross section of the support material placed at the joint of the surface material can be made less than 90mm square (90mm long x 90mm wide), thereby reducing the volume of material.

[0021] In the second aspect of the horizontal structural member of the present invention, in the first aspect, the two short sides of the four sides and the center passage of the panel are fixed to the beam, and the two long sides of the four sides are fixed to the receiving material.

[0022] In the second embodiment, the two long sides of the four sides of the face material are fixed to the support material. Therefore, in the horizontal structural surface of the second embodiment, the cross section (length and width dimensions) of the support material that supports the two long sides of the face material can be made less than 90 degrees, which makes it possible to efficiently reduce the volume of material. Effect of the Invention

[0023] As described above, the horizontal structural member according to the present invention can achieve a high floor ratio with specifications that require less effort in design and construction, and can also reduce the material volume. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is an exploded perspective view showing a portion of a horizontal structural surface according to an embodiment of the present invention, as an example of a case in which the horizontal structural surface is used as a floor of a wooden building. [Diagram 2] FIG. 2 is a plan view showing a part of the horizontal structural face shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, the horizontal structural surface 10F according to this embodiment will be described with reference to Figs. 1 and 2. In this embodiment, the case where the horizontal structural surface 10F according to the present invention is used as a floor of a building 10, which is a wooden building, will be described as an example. Note that the arrow X shown appropriately in each figure indicates the girder direction of the building 10, the arrow Y indicates the gable direction of the building 10, and the arrow Z indicates the height direction of the building 10. However, the girder direction X and the gable direction Y are defined for the convenience of explanation, and the horizontal structural surface according to the present invention is not limited thereto.

[0026] (horizontal composition) As shown in Figures 1 and 2, the horizontal structural surface 10F constitutes the floor structural surface that constitutes the floor section of the upper floor of a building 10 constructed by a wooden frame construction method. The horizontal structural surface 10F has a structural form in which multiple surface materials are fixed to the floor structure 12 of the upper floor of the building 10. The floor structure 12 includes multiple beams 20 with the girder direction X of the building as the longitudinal direction, and multiple support members 30 that are perpendicular to the beams 20.

[0027] (beam) The multiple beams 20 have girths 21 arranged on the outer periphery of the building 10 and multiple floor beams 22 arranged inside the girths 21. The girths 21 and floor beams 22 are arranged in parallel with each other at a predetermined interval in the gable direction Y.

[0028] The girth 21 and floor beam 22 are wooden square timbers, and although the material is not particularly limited, for example, solid wood or laminated wood using cypress, beige pine, or beige pine may be used. In one example of this embodiment, the girth 21 and floor beam 22 are made of structural laminated wood.

[0029] Structural laminated timber is formed by gluing together multiple laminas (sawn planks) that are graded based on the required strength along the vertical direction (height direction). The lamina grades are strength grades determined based on the JAS standard, for example, and are categorized by the grade of the combination of bending Young's modulus E and F, which represents bending strength. When the beam 20 is made of structural laminated timber, it may be made of different grade laminated timber or the same grade laminated timber, but it is more preferable to make it of different grade laminated timber that has a symmetrical configuration in which the outer layers of the multiple laminas have stronger strength in the stacking direction (height direction).

[0030] The length and width of the girth 21 can be set, for example, from 150mm to 450mm for the length (height) and from 105mm to 150mm for the width. The length and width of the floor beam 22 can be set, for example, from 120mm to 450mm for the length (height) and from 105mm to 150mm for the width.

[0031] (received material) The receiving material 30 is arranged so that its longitudinal direction is the gable direction Y and connects between the multiple beams 20. The multiple receiving materials 30 are arranged parallel to each other at a predetermined interval in the girder direction X between two adjacent beams 20. The receiving materials 30 are provided to reinforce the joint (seam) portion P1 of the face material 40 described later, and are made of wooden square timber.

[0032] The material of the support material 30 is not particularly limited, but may be solid wood or laminated wood made of, for example, Japanese cypress, Japanese beech, or Japanese laurel. In one example of this embodiment, the girth 21 and floor beam 22 are made of structural laminated wood.

[0033] The length and width of the receiving material 30 are set to less than 90 mm. For example, the length (height) can be set to 45 mm to 75 mm, and the width (width) can be set to 45 mm to 75 mm. In addition, commonly used square timber with a 45-sided shape (length 45 mm x width 45 mm) or a square timber with a length of 60 mm x width 45 mm can be used.

[0034] (Surface material) The surface material 40 is composed of a rectangular plate material. A plurality of the surface materials 40 are laid on the floor structure 12 constructed of a plurality of beams 20 and a plurality of support members 30 to form a floor base. Each surface material 40 is fixed to the beams 20 and support members 30 by using nails 50, which will be described later.

[0035] The material of the surface material 40 is not particularly limited, but may be, for example, solid wood, plywood (including structural plywood), CLT material (Cross Laminated Timber), Laminated Veneer Lumber (LVL), molded fiberboard (Medium Density Fiberboard), etc. In one example of this embodiment, the surface material 40 is made of structural plywood.

[0036] The face material 40 is preferably made of a thick material, and when made of structural plywood, the thickness is more preferably set to 24 mm or more.

[0037] (nail) The nail 50 may be an iron round nail such as an N nail or a CN nail as specified by the JIS standard, and in one example of this embodiment, the nail 50 is an N nail. The outer diameter of the nail 50 may be set to 3 mm to 3.5 mm, and the total length may be set to 70 mm to 80 mm. In addition, when the beam 20 or the receiving member 30 is made of laminated timber, it is preferable to set the total length of the nail 50 so that it is placed across the boundary between the lamina that constitutes the upper surface of the beam 20 or the face member 40 and the lamina of a different grade that is placed on the inner layer side. This effectively suppresses cracks that occur at the boundary between the laminas due to a load (for example, a vertical load) acting on the beam 20 or the receiving member 30, which is preferable in terms of increasing the strength of the horizontal structural member 10F.

[0038] (Horizontal structure specifications) Under conventional standards, the specifications (structural form) of horizontal structural components are determined by a combination of the type of surface material, the specifications of connecting members (type and installation interval), the specifications of joists (dimensions and installation interval), and the joint specifications between the joists and beams.

[0039] The specifications of the horizontal structural face 10F according to this embodiment include the specifications of the nails 50. They include the specifications of the face material and the specifications of the nails 50. The specifications of the face material 40 are the result of selecting elements including the type of face material and the board thickness. The specifications of the nails 50 are the result of selecting elements including the type and dimensions of the nails 50, the pitch L1 (driving interval) of the nails 50, and the driving style. Therefore, the specifications of the horizontal structural face 10F are the result of selecting elements including the materials, dimensions, and shapes of the face material 40 and the nails 50.

[0040] The nail 50 driving format refers to the arrangement of the nails 50 driven into a single panel 40, and known formats include the "river" format, the "square" format, and the "day" format. In this embodiment, in order to achieve a floor height ratio of over four times, the nails 50 are driven into the "day" format. That is, the four sides and center line of the panel 40 are fixed to the beam 20 or the receiving member 30 with nails 50. The center line of the panel 40 refers to the line that runs through the center of the long side of the panel 40 in the width direction in the short side direction.

[0041] Hereinafter, as necessary, the nail 50 driving area on the two short sides of the four sides of the panel 40 will be referred to as the short side fixing area 40A, the nail 50 driving area on the two long sides of the four sides of the panel 40 will be referred to as the long side fixing area 40B, and the nail 50 driving area in the center of the panel 40 will be referred to as the center fixing area 40C.

[0042] In this embodiment, the long sides of the face material 40 are arranged along the gable direction Y of the building 10. Therefore, the short side fixing regions 40A of the two short sides and the center passage fixing region 40C are fixed to the beam 20 (the girth 21 or the floor beam 22). In addition, the long side fixing regions 40B of the two long sides are fixed to the receiving material 30. In addition, since the receiving material 30 is provided at the joint portion P1 of the adjacent face materials 40, the long side fixing regions 40B of the two face materials 40 are arranged on the upper surface of the receiving material 30. For this reason, nails 50 are driven into the upper surface of the receiving material 30 along the longitudinal direction of the receiving material 30 with two rows of nails arranged in the upper surface.

[0043] In the specifications of the above horizontal structural member 10F, in this embodiment, the pitch L1 of the nails 50 is set to 75 mm or less, making it possible to set the floor magnification of the horizontal structural member 10F to 5 times or more (see Figure 2).

[0044] [Example] A number of examples of the horizontal structural member 10F according to this embodiment will be described below. In the comparative example and each example, the surface material 40 is made of structural plywood with a plate thickness of 24 mm. The nails 50 are made of JIS standard N nails, and the driving style is set to a square shape. The dimensions of the beams 20 are set to a vertical dimension of 150 mm and a horizontal dimension of 105 mm. The dimensions of the support material 30 are set to a vertical dimension of 60 mm and a horizontal dimension of 45 mm. Other specifications of the floor structure 12 (installation intervals of the beams 20, joint specifications with the columns 16) conform to the specifications set forth in the Building Standards Act.

[0045] The following Table 1 shows comparative examples having different pitches L1 of the nails 50 and floor magnification factors of the horizontal structural face 10F according to each embodiment. [Table 1]

[0046] As shown in this figure, in the comparative example in which the pitch L1 of the nails 50 is set to 150 [mm], the floor multiplier is 4.0 times, whereas in Examples 1 to 3 in which the pitch L1 of the nails 50 is set to less than 75 [mm], the floor multiplier is all 5 times or more.

[0047] (Action and Effects) As explained above, in this embodiment, the horizontal structural face 10F is formed by fixing a plurality of surface members 40 to a floor structure 12 including a plurality of beams 20 arranged in parallel and a support member 30 that is perpendicular to the beams 20 and provided at a joint portion P1 of the surface member 40. In addition, the horizontal structural face 10F has a structural form in which the floor multiplier is set to 5 times or more by fixing the four sides and center passage of the surface member 40 to the beams 20 or the support member 30 using connecting members, and while this structural form can obtain a high floor multiplier, detailed strength calculations including the type of the floor structure 12 are not required, and the design effort is reduced.

[0048] Furthermore, by setting the pitch of the fastening members to 75 mm or less, nails 50 can be used as fastening members, which shortens the work time and reduces the labor required for construction compared to when screws are used as fastening members.

[0049] Furthermore, by using nails 50 as connecting members, a structural form can be used that achieves a high floor ratio, while the cross section of the receiving material 30 placed at the joint portion P1 of the surface material 40 can be made less than 90° square (90 mm long x 90 mm wide), thereby reducing the volume of material. In addition, when the floor beams 22 are constructed as exposed beams and the lower parts of the floor beams 22 are exposed in the living space on the lower floor to be used as a design surface, the area that can be exposed (design surface) can be increased by making the cross-section of the receiving material 30 smaller.

[0050] Furthermore, in this embodiment, the two long sides of the four sides of the face material 40, i.e., the long side fixing areas 40B, are fixed to the receiving material 30. For this reason, in the horizontal structural face 10F, the cross section (length and width dimensions) of the receiving material 30 that receives the two long sides of the face material 40 can be made less than 90 degrees square, and the material volume can be efficiently reduced. [supplementary explanation]

[0051] In the above embodiments, the numerical range indicated using "~" means a range including the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the above embodiments, a combination of two or more preferred aspects is a more preferred aspect. The floor structural surface according to the above embodiment can be modified within the scope of the invention.

[0052] In the above embodiment, the horizontal structural surface constitutes a floor structural surface of a building, but the present invention is not limited to this. The horizontal structural surface according to the present invention may be applied to a roof structural surface of a building. [Explanation of symbols]

[0053] 10 Buildings (wooden structures) 10F horizontal composition 12 floor set 20 beams 30 Received material 40 Surface material 40A Short side fixed area (two short sides) 40B Fixed area on long side (two long sides) 40C Nakadori 50 nails

Claims

1. A horizontal structural surface in which multiple surface materials are fixed to the floor framing of a wooden building, A plurality of beams arranged in parallel; A support member perpendicular to the beam and provided at a joint portion of the surface material; and nails for fixing the four sides and center of the surface material to the beam or the receiving material; The length and width of the receiving material are set to less than 90 mm, When the nails are driven in at a pitch of 75 mm or less, The floor multiplier is set to 5x or more. Horizontal composition.

2. The surface material is fixed to the beam at the two short sides and the center passage of the four sides, and the two long sides of the four sides are fixed to the receiving material. The horizontal structural surface according to claim 1 .

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