Load-bearing wall and manufacturing method thereof

Abstract

A load-bearing wall S1 includes: a framework part 5 including a pair of posts 1, 1 arranged such that longitudinal directions thereof are mutually parallel, a pair of lateral structural materials 2, 2 intersecting the pair of posts 1, 1 and arranged such that longitudinal directions thereof are mutually parallel, and a floor backing material 3 provided at a position shifted to the other side (upper side) relative to one (lower lateral structural material 2) of the pair of lateral structural materials 2, 2 and extending in a direction (face direction D3) orthogonal to the longitudinal direction of the post 1 and longitudinal direction of the lateral structural material 2; and a load-bearing surface material 10 including a gypsum board, the load-bearing surface material 10 being fixed at least to the pair of posts 1, 1 and the upper lateral structural material 2 of the pair of lateral structural materials 2, 2. A gap 20 is formed between the load-bearing surface material 10 and the floor backing material 3. When the dimension of the load-bearing surface material 10 in the longitudinal direction of the lateral structural material 2 is W, the dimension C1 of the gap 20 is 0.5W × sin (rad / 30) or more.

Description

LOAD-BEARING WALL AND MANUFACTURING METHOD THEREOF

[0001] The present invention relates to a load-bearing wall and a manufacturing method thereof.

[0002] Wooden construction methods can be broadly classified into two categories: wooden framework methods and wooden frame wall construction methods. Each of these construction methods can improve seismic resistance through the use of load-bearing walls. Load-bearing walls are generally classified into two categories: braced load-bearing walls and surface material load-bearing walls. A braced load-bearing wall is a structural wall in which braces are installed between the posts configuring a wall. A surface material load-bearing wall is a structural wall in which a load-bearing surface material is nailed or otherwise fastened to a post and a lateral structural material such as a beam, or to a wooden frame wall.

[0003] In conventional load-bearing walls, wood-based surface materials such as structural plywood, particleboards, and the like are generally used as load-bearing surface materials. On the other hand, construction methods using a gypsum board as a load-bearing surface material have been recently attracting attention, and the adoption thereof is increasing. An advantage of using a gypsum board as a load-bearing surface material includes ensuring seismic resistance as well as fire resistance.

[0004] Patent Publication WO 2023 / 058470 A1 relates to wooden structural load-bearing walls, construction methods for wooden structural load-bearing walls, methods for increasing the wall factor of wooden structural load-bearing walls, and gypsum-based load-bearing surfaces that are configured to increase the wall factor without relying on increasing the maximum strength of the surface material itself, increasing the ultimate displacement, or the placement of additional reinforcement or stiffening materials.

[0005] Surface material load-bearing walls can be classified into standard specification, inner corner specification, and floor above bottom beam specification, so-called yukagachi specification in Japan. The manner in which the load-bearing surface material is fastened differs for each of the above-mentioned specifications.

[0006] With a standard specification load-bearing wall, a load-bearing surface material is fastened to at least two posts that extend in a vertical direction and to a pair of lateral structural materials that are arranged above and below and extend in a lateral direction. With an inner corner specification load-bearing wall, the load-bearing surface material is fastened to at least one of a pair of posts extending in the vertical direction and a pair of lateral structural materials arranged above and below and extending in the lateral direction, but an edge part of the load-bearing surface material facing the inner corner side is not fastened to the post.

[0007] With a floor above bottom beam specification load-bearing wall, the load-bearing surface material is fastened to at least two posts extending in the vertical direction and to the upper lateral structural material of a pair of lateral structural materials arranged above and below and extending in the lateral direction, but a lower edge part of the load-bearing surface material is not fastened to the lower lateral structural material. With the floor above bottom beam specification, a floor backing is positioned above the lower lateral structural material, and the lower edge part of the load-bearing surface material is positioned above the floor backing.

[0008] The inventors of the present application found that the expected seismic resistance of a floor above bottom beam specification load-bearing wall using a gypsum board may be significantly lower than the actual seismic resistance. Specifically, the inventors of the present application found that a floor above bottom beam specification load-bearing wall using a gypsum board as a load-bearing surface material may experience a situation where the desired seismic resistance is compromised at an early stage when subjected to actual vibration, and the resulting seismic resistance is significantly lower than the expected resistance. Furthermore, the inventors of the present application found that the cause was the contact between the gypsum board and the floor.

[0009] Although a gypsum board solidifies with water, a main component thereof is an inorganic material that is relatively easily damaged. Furthermore, a gypsum board is an inorganic material, and thus partial damage from contact tends to affect overall strength. Specifically, it was found that with a floor above bottom beam specification load-bearing wall, when shaking occurs due to an earthquake, wind, or the like, the gypsum board and the floor come into contact with each other at an early stage, and this effect causes a drastic reduction in seismic resistance.

[0010] As described above, a situation in which the expected seismic resistance is much lower than the actual seismic resistance can occur specifically with floor above bottom beam specification load-bearing walls using a gypsum board as a load-bearing surface material. Therefore, it is necessary to ensure proper seismic resistance in load-bearing walls using a gypsum board, for example, through new innovations that are not necessarily required in load-bearing walls using wood surface materials.

[0011] Furthermore, with an inner corner specification load-bearing wall using a gypsum board as a load-bearing surface material, the load-bearing surface material can contact a wall portion forming an inner corner along with the load-bearing surface material. As with the floor above bottom beam specification, the expected seismic resistance of the inner corner specification may be much lower than the actual seismic resistance.SUMMARY OF THE INVENTION

[0012] In view of the foregoing, an object of the present invention is to improve the seismic resistance of a floor above bottom beam or inner corner specification load-bearing wall provided with a gypsum board as a load-bearing surface material over the conventional.

[0013] Embodiments of the present invention relate to the following [1] to [3].

[0014] [1]　A load-bearing wall, comprising: a framework part including a pair of first structural materials arranged such that longitudinal directions thereof are mutually parallel, a pair of second structural materials intersecting the pair of first structural materials and arranged such that longitudinal directions thereof are mutually parallel, and a third structural material provided at a position shifted to the other side relative to one of the pairs of second structural materials and extending in a direction orthogonal to each of the longitudinal directions of the first and second structural materials; and a load-bearing surface material including a gypsum board, the load-bearing surface material being fixed at least to the pair of first structural materials and to the other of the pair of second structural materials, wherein a gap is formed between the load-bearing surface material and the third structural material, and when the dimension of the load-bearing surface material in the longitudinal direction of the second structural material is W, the dimension of the gap is 0.5W × sin (rad / 30) or more.

[0015] [2]　A method for manufacturing a load-bearing wall including: a framework part including a pair of first structural materials arranged such that longitudinal directions thereof are mutually parallel, a pair of second structural materials intersecting the pair of first structural materials and arranged such that longitudinal directions thereof are mutually parallel, and a third structural material provided at a position shifted to the other side relative to one of the pairs of second structural materials and extending in a direction orthogonal to each of the longitudinal directions of the first and second structural materials; and a load-bearing surface material including a gypsum board, the load-bearing surface material being fixed at least to the pair of first structural materials and to the other of the pair of second structural materials, a gap being formed between the load-bearing surface material and the third structural material, the method for manufacturing a load-bearing wall, comprising: a surface material dimension specifying step for specifying a dimension of the load-bearing surface material in the longitudinal direction of the second structural members as W; a gap dimension determining step for determining the dimension of the gap within a range of 0.5W × sin (rad / 30) or more; and an assembly step for fixing the load-bearing surface material to the framework part such that the dimension of the gap is the gap determined in the gap dimension determining step.

[0016] [3]　A method for manufacturing a load-bearing wall including: a framework part including a pair of first structural materials arranged such that longitudinal directions thereof are mutually parallel, a pair of second structural materials intersecting the pair of first structural materials and arranged such that longitudinal directions thereof are mutually parallel, and a third structural material provided at a position shifted to the other side relative to one of the pairs of second structural materials and extending in a direction orthogonal to each of the longitudinal directions of the first and second structural materials; and a load-bearing surface material including a gypsum board, the load-bearing surface material being fixed at least to the pair of first structural materials and to the other of the pair of second structural materials, and a gap being formed between the load-bearing surface material and the third structural material, the method for manufacturing a load-bearing wall, comprising: a surface material dimension specifying step for specifying a dimension of the load-bearing surface material in the longitudinal direction of the second structural members as W; a gap dimension determining step for determining the dimension of the gap within a range of 0.5W × sin (rad / 30) × (1 + β1) × β2 or more; and an assembly step for fixing the load-bearing surface material to the framework part such that the dimension of the gap is the gap determined in the gap dimension determining step. (In the equation above, β1 is the eccentricity of rotational axis, which is a coefficient that is 0 when the position of the rotational axis of the load-bearing surface material when subjected to vibration is at the center in the direction of a side of the dimension W of the load-bearing surface material, and is 1 when the position is at an end part of the load-bearing surface material in the direction of the side of the dimension W of the load-bearing surface material. β2 is a coefficient that is 1 when the lateral nail resistance of the load-bearing surface material is 500 N, and is 0 when the lateral nail resistance is 0 N.)

[0017] The present invention improves seismic resistance of a floor above bottom beam or inner corner specification load-bearing wall provided with a gypsum board as a load-bearing surface material over the conventional.

[0018] FIG. 1 is a front view of a load-bearing wall according to Embodiment 1;FIG. 2 is a longitudinal cross-sectional view of the load-bearing wall along line II-II of FIG. 1;FIG. 3 is a diagram for describing a condition in which the load-bearing wall depicted in FIG. 1 is subjected to vibration;FIG. 4 is a front view of a load-bearing wall according to Embodiment 2;FIG. 5 is a front view of a load-bearing wall according to Embodiment 3; andFIG. 6 is a longitudinal cross-sectional view of a framework part for testing used in the Examples and depicts a condition in which a load-bearing surface material is fixed to the framework part for testing.MODE FOR CARRYING OUT THE INVENTION

[0019] Embodiments of the present invention will be described below.

[0020] <Embodiment 1> FIG. 1 is a front view of a load-bearing wall S1 according to Embodiment 1. A load-bearing wall S1 depicted in FIG. 1 has: a pair of posts 1, 1; a pair of lateral structural materials 2, 2; a floor backing material 3; a receiving material 4; and a load-bearing surface material 10.

[0021] The pair of posts 1, 1, pair of lateral structural materials 2, 2, floor backing material 3, and receiving material 4 configure a framework part 5. The load-bearing wall S1 is configured by fixing the load-bearing surface material 10 to the framework part 5. The load-bearing wall S1 is of a floor above bottom beam specification of wooden construction, so-called yukagachi specification in Japan. In the present embodiment, the pair of posts 1, 1, pair of lateral structural materials 2, 2, floor backing material 3, and receiving material 4 are made of wood. Note that so long as at least the pair of posts 1, 1 and pair of lateral structural materials 2, 2 in the framework part 5 are made of wood, the other members may not be made of wood.

[0022] The pair of posts 1, 1 are arranged such that longitudinal directions thereof are mutually parallel. The longitudinal directions of the pair of posts 1, 1 are parallel to a vertical direction D1. The pair of posts 1, 1 are aligned in a horizontal direction D2.

[0023] The pair of lateral structural materials 2, 2 intersect with the pair of posts 1, 1, and specifically in this example, intersect orthogonally, and are arranged such that longitudinal directions thereof are mutually parallel. The longitudinal directions of the pair of lateral structural materials 2, 2 are parallel to the horizontal direction D2. The pair of lateral structural materials 2, 2 are aligned in the vertical direction D1.

[0024] The upper lateral structural material 2 of the pair of lateral structural materials 2, 2 is connected to an upper end of each of the pair of posts 1, 1, and is fixed in a state straddled between the upper ends of the pair of posts 1, 1. The lower lateral structural material 2 of the pair of lateral structural materials 2, 2 is connected to a lower end of each of the pair of posts 1, 1, and is fixed in a state straddled between the lower ends of the pair of posts 1, 1. The post 1 and lateral structural material 2 are connected, for example, by a nail or the like.

[0025] The pair of posts 1, 1 and pair of lateral structural materials 2, 2 configure a quadrangular frame body. The frame body configured of the pair of posts 1, 1 and pair of lateral structural materials 2, 2 may be manufactured by the wooden framework construction method or by the wooden frame wall construction method. Note that a stud may be provided between the pair of posts 1, 1, or a brace may be provided.

[0026] The floor backing material 3 is arranged at a position shifted to the upper lateral structural material 2 side relative to the lower lateral structural material 2. In the present embodiment, the floor backing material 3 is disposed in the vicinity of the lower lateral structural material 2, and specifically, the floor backing material 3 is attached to an upper surface of the lower lateral structural material 2. Thereby, the floor backing material 3 is positioned shifted to the upper lateral structural material 2 side relative to the lower lateral structural material 2.

[0027] FIG. 2 is a longitudinal cross-sectional view of the load-bearing wall S1 along line II-II of FIG. 1. Referring to FIGS. 1 and 2, the floor backing material 3 extends from the lower lateral structural material 2 in a face (or front) direction D3, which is orthogonal to each of the longitudinal directions of the post 1 and the lateral structural material 2. In other words, the floor backing material 3 extends in the face direction D3, which is orthogonal to each of the vertical direction D1 and horizontal direction D2, respectively.

[0028] The floor backing material 3 is a board, which may be, for example, plywood, particle board, or the like. The floor backing material 3 may be fastened by a nail or the like to the lower lateral structural material 2.

[0029] The receiving material 4 is attached to the upper surface of a portion of the floor backing material 3 that overlaps with the lower lateral structural material 2. The receiving material 4 is a material having a square cross-sectional area and a longitudinal direction. The receiving material 4 is arranged such that the longitudinal direction thereof is parallel to the horizontal direction D2 and the longitudinal direction of the lower lateral structural material 2. The receiving material 4 may be fastened by a nail or the like to the floor backing material 3 and lower lateral structural material 2.

[0030] The load-bearing surface material 10 is fixed to at least one of the pair of posts 1, 1 and the upper lateral structural material 2 of the pair of lateral structural materials 2, 2. Specifically, the load-bearing surface material 10 is fixed to the pair of posts 1, 1 and the upper lateral structural material 2, while not being fixed to the lower lateral structural material 2, but being fixed to the receiving material 4. More specifically, the load-bearing surface material 10 is fixed to the surfaces of the pair of posts 1, 1, the upper lateral structural material 2, and the surface of the receiving material 4 in the face direction D3. Therefore, load-bearing wall S1 is a load-bearing wall of a sealed posts (pillars) specification, so-called “OOKABE” in Japan.

[0031] Furthermore, the load-bearing surface material 10 is fixed to at least the pair of posts 1, 1 and the upper lateral structural material 2 such that a gap 20 in the vertical direction D1 is formed between the load-bearing surface material 10 and the floor backing material 3. Code C1 in FIGS. 1 and 2 indicates the dimension of the gap 20 in the vertical direction D1. The gap 20 may be concealed by a decorative board or the like or may be filled with a filler. The gap 20 is formed in the load-bearing wall S1; therefore, the load-bearing wall S1 may be considered a suitable application to be configured as a sealed posts (pillars) specification of load-bearing wall for forming an exterior wall. In the present embodiment, the load-bearing wall S1 is configured as a sealed posts (pillars) specification load-bearing wall for forming an exterior wall. However, the application of the load-bearing wall S1 (as well as the application of load-bearing walls S2 and S3 described later) is not particularly limited.

[0032] The load-bearing surface material 10 is quadrangular, and rectangular in this example. The load-bearing surface material 10 is overlaid on the surfaces of the pair of posts 1, 1, the upper lateral structural material 2, and the receiving material 4 in the face direction D3, and fixed by nails or other fastening members 11 that penetrate the overlapped portion and are driven or screwed into the pair of posts 1, 1, the upper lateral structural material 2, and the receiving material 4. As depicted in FIG. 1, a plurality of the fastening members 11 are provided penetrating through the load-bearing surface material 10, which are aligned in the longitudinal direction of each of the pair of posts 1, 1. The plurality of fastening members 11 are driven or screwed into each of the pair of posts 1, 1. The load-bearing surface material 10 has a plurality of fastening members 11 penetrating the load-bearing surface material 10, which are aligned in the longitudinal direction of the upper lateral structural material 2. The plurality of fastening members 11 are driven or screwed into the upper lateral structural material 2. The load-bearing surface material 10 has a plurality of fastening members 11 penetrating the load-bearing surface material 10, which are aligned in the longitudinal direction of the receiving material 4. The plurality of fastening members 11 are driven or screwed into the receiving material 4.

[0033] Note that as described above, a stud may be provided between the pair of posts 1, 1, or a brace may be provided. In this case, the fastening member 11 penetrating through the load-bearing surface material 10 may be driven or screwed into the stud or brace.

[0034] The load-bearing surface material 10 includes a gypsum board. A gypsum board is inclusive of various forms of gypsum boards, including regular board, reinforced gypsum board, structural gypsum board, and the like. From the perspective of improving the seismic resistance of the load-bearing wall S1, the load-bearing surface material 10 may be a gypsum board with a lateral naile resistance of 500 N or more as stipulated in JIS A 6901:2014, which is a standard in Japan. However, the load-bearing surface material 10 may be, for example, a gypsum board with a lateral nail resistance of 200 N or more and less than 500 N, and is not particularly limited. The gypsum board thickness is generally set at 9.5 mm, 12.5 mm, 15.0 mm, 16.0 mm, 18.0 mm, 21.0 mm, and 25.0 mm. The thickness of the load-bearing surface material 10 may be any of the dimensions listed above but is not particularly limited.

[0035] The dimension C1 of the gap 20 between the load-bearing surface material 10 and the floor backing material 3 is set to be 0.5W × sin (rad / 30) or more when the dimension (width dimension) of the load-bearing surface material 10 in the longitudinal direction (horizontal direction D2) of the lateral structural material 2 is W.

[0036] The dimension C1of the gap 20 is set based on (1 / 30) rad, which is the safe limit deformation angle for wooden construction. FIG. 3(A) depicts how the load-bearing surface material 10 has been rotated by (1 / 30) rad around the center in the width direction. In this case, the position of the lower corner part 10C2, which moves downward of the two lower corner parts 10C1, 10C2 of the load-bearing surface material 10, is lowered by 0.5W × sin (rad / 30) relative to before deformation.

[0037] If the load-bearing surface material 10 rotates due to shaking and the lower corner part 10C2 thereof contacts the floor backing material 3, the lower corner part 10C2 of the load-bearing surface material 10 may become damaged. In consideration of this situation, for the load-bearing wall S1, the dimension C1 of the gap 20 between the load-bearing surface material 10 and the lower lateral structural material 2 is set to 0.5 W × sin (rad / 30) or more. Thereby, for example, if the deformation is within the safety limit deformation angle, the situation where the lower corner part 10C2 of the load-bearing surface material 10 contacts the floor backing material 3 can be avoided, even if the load-bearing surface material 10 is deformed due to shaking. Although cracking due to contact tends to affect the overall strength of the gypsum board, cracking, and the like can be avoided by setting the dimension C1 of the gap 20 so as to be 0.5W × sin (rad / 30) or more. Thereby, the load-bearing surface material 10 including the gypsum board can maintain a proper seismic resistance.

[0038] When shaking occurs in load-bearing wall S1 due to an earthquake, wind, or the like, the load-bearing surface material 10 often rotates around the center in the width direction, as depicted in FIG. 3(A). On the other hand, the load-bearing surface material 10 may rotate around one of the two lower corner parts 10C1, 10C2, for example, the lower corner part 10C1, as depicted in FIG. 3(B). If the load-bearing surface material 10 rotates by (1 / 30) rad around the lower corner part 10C1, for example, the position of the lower corner part 10C2 of the load-bearing surface material 10 that moves downward moves more significantly than in FIG. 3(A) and is lowered by W × sin (rad / 30) relative to before deformation.

[0039] In consideration of the situation where the load-bearing surface material 10 rotates around the lower corner part 10C1 as described above, the dimension C1 of the gap 20 may be set to W × sin (rad / 30) or more from the perspective of more securely avoiding contact between the load-bearing surface material 10 and the floor backing material 3.

[0040] On the other hand, if the dimension C1 of the gap 20 becomes too large, problems may arise, such as loss of weather resistance, loss of appearance, and reduction in strength due to the reduction in volume of the load-bearing surface material 10 and / or the fastening member 11. Therefore, it is not necessarily preferred to make the dimension C1 of the gap 20 excessively large. From this perspective, the dimension C1 of the gap 20 may be set to 0.5W × sin (rad / 30) or more and 2W × sin (rad / 30) or less, 0.5W × sin (rad / 30) or more and 1.5W × sin (rad / 30) or less, or 0.5W × sin (rad / 30) or more and W × sin (rad / 30) or less. The dimension C1 of the gap 20 may be set to be W × sin (rad / 30) or more and 2W × sin (rad / 30) or less, or W × sin (rad / 30) or more and 1.5W × sin (rad / 30) or less.

[0041] The width dimension (W) of the gypsum board is generally 900 to 1000 mm. For example, if a gypsum board with a width dimension of 1000 mm is employed as the load-bearing surface material 10, the dimension C1 of the gap 20 is set to 16.7 mm or more when based on 0.5W × sin (rad / 30) or more. The dimension C1 of the gap 20 is set to 33.4 mm or more when based on W × sin (rad / 30) or more. If the width dimension (W) of the gypsum board is 900 to 1000 mm, the receiving material 4 with a height of 60 mm is generally used. When fastening the load-bearing surface material 10 to the receiving material 4 using the fastening member 11, the overlapping range between the load-bearing surface material 10 and the receiving material 4 is preferably 25 mm or more in order to ensure suitable fixing strength. In this case, a preferred value of the dimension C1 of the gap 20 is 35 mm or less. Therefore, the dimension C1 of the gap 20 may be 35 mm or less. From this perspective, the dimension C1 of the gap 20 may be set to be 0.5W × sin (rad / 30) or more and W × sin (rad / 30) or less.

[0042] When manufacturing the load-bearing wall S1, the dimension C1 of the gap 20 is preferably set in advance before construction. In this case, as an example, the width dimension W of the load-bearing surface material 10 in the longitudinal direction (horizontal direction D2) of the lower lateral structural material 2 is first identified (surface material dimension specifying step). Next, the dimension C1 of the gap 20 is determined within the range of "0.5W × sin (rad / 30)" or more as described above (gap dimension determining step). Thereafter, after the framework part 5 is formed, the load-bearing surface material 10 is fixed to the framework part 5 such that the dimension C1 of the gap 20 between the load-bearing surface material 10 and the floor backing material 3 is the value determined in the gap dimension determining step (assembly step).

[0043] As described above, the load-bearing surface material 10 may be, for example, a gypsum board with a lateral nail resistance of 500 N or more. If the lateral nail resistance is increased, when the load-bearing surface material 10 and the floor backing material 3 come into contact due to vibration, the load on a surrounding portion of the fastening member 11 increases, and the risk of premature deterioration in seismic resistance due to contact between the load-bearing surface material 10 and the floor backing material 3 increases. On the other hand, if the lateral nail resistance is relatively small, such as less than 500 N or the like, even when the load-bearing surface material 10 and the floor backing material 3 come into contact due to vibration, the load on the surrounding portion of the fastening member 11 is suppressed by the load-bearing surface material 10 absorbing the impact. Thus, the progress of seismic resistance deterioration caused by contact between the load-bearing surface material 10 and the floor backing material 3 tends to be mitigated. In consideration of this point as well as the lateral nail resistance A(N) of the load-bearing surface material 10, the dimension C1 of the gap 20 may be determined such that if the lateral nail resistance A(N) is large, the dimension C1 of the gap 20 is larger, and if the lateral nail resistance A(N) is small, the dimension C1 of the gap 20 is smaller.

[0044] Specifically, the dimension C1 may be set based on the following equation.

[0045] In the equation above, β1 represents the eccentricity of the rotational axis of the load-bearing surface material 10, and β2 represents a coefficient that varies with the value of the lateral nail resistance of the load-bearing surface material 10. The eccentricity of the rotational axis β1 is a coefficient that is 0 when the position of the rotational axis of the load-bearing surface material 10 when subjected to vibration is at the center in the direction of a side of the dimension W of the load-bearing surface material 10 and 1 when the position is at an end part of the load-bearing surface material 10 in the direction of the side of the dimension W. The eccentricity of the rotational axis β1 is determined by 2x / W, where x is the distance from the center position in the direction of the side of the dimension W of the load-bearing surface material 10 to the aforementioned rotational axis. The position of the rotational axis may be identified through experimentation, simulation, or the like. Coefficient β2 is 1 when the lateral nail resistance of the load-bearing surface material 10 is 500 N, and is 0 when the lateral nail resistance is 0 N. Coefficient β2 is determined by A / 500, where A is the lateral nail resistance.

[0046] The equation above presents the dimension C1 to be 16.7 mm or more when a gypsum board with the dimension W of 1000 mm is employed as the load-bearing surface material 10, the position of the rotational axis of the load-bearing surface material 10 is at the center in the direction of the side of the dimension W, and the lateral nail resistance of the load-bearing surface material 10 is 500 N. On the other hand, when a gypsum board with a lateral nail resistance A of 750 (N) and width dimension W of 1000 mm is employed as the load-bearing surface material 10, and the position of the rotational axis of the load-bearing surface material 10 is at the center in the direction of the side of the dimension W, the dimension C1 is presented to be 25.00 mm or more by the equation above. The equation above was found through experiments and the like.

[0047] In the equation above, when the lateral nail resistance of the load-bearing surface material 10 is less than 500 N, a range of dimensions can be presented with a lower limit value of less than 0.5W × sin (rad / 30) as the dimension C1 of the gap 20. In this case, the numerical value of the dimension C1 may be determined from a range of dimensions with a lower limit value of less than 0.5W × sin (rad / 30) presented by the equation above. In other words, the dimension C1 of the gap in the load-bearing wall S1 may be "0.5W × sin (rad / 30) × (1 + β1) × β2" or more when "0.5W × sin (rad / 30) × (1 + β1) × β2" is less than "0.5W × sin (rad / 30)". However, even in this case, it goes without saying that setting the dimension C1 to 0.5W × sin (rad / 30) or more is desirable from the perspective of ensuring seismic resistance.

[0048] Using the equation above, it is possible to simply set a suitable dimension C1 of the gap 20, corresponding to the lateral nail resistance of the load-bearing surface material 10.

[0049] As described above, the load-bearing wall S1 according to Embodiment 1 includes: the framework part 5 including the pair of posts 1, 1 (corresponding to first structural material) arranged such that longitudinal directions thereof are mutually parallel, the pair of lateral structural materials 2, 2 (corresponding to second structural material) intersecting the pair of posts 1, 1 and arranged such that longitudinal directions thereof are mutually parallel, and the floor backing material 3 (corresponding to third structural material 3) provided at a position shifted to the other (upper lateral structural material 2) side (upper side) relative to one (lower lateral structural material 2) of the pair of lateral structural materials 2, 2 and extending in a direction (face direction D3) orthogonal to the longitudinal direction of the post 1 and longitudinal direction of the lateral structural material 2; and the load-bearing surface material 10 including a gypsum board, the load-bearing surface material 10 being fixed at least to the pair of posts 1, 1 and the upper lateral structural material 2 of the pair of lateral structural materials 2, 2. Furthermore, the gap 20 is formed between the load-bearing surface material 10 and the floor backing material 3. Furthermore, when the dimension of the load-bearing surface material 10 in the longitudinal direction of the lateral structural material 2 is W, the dimension of the gap 20 is 0.5W × sin (rad / 30) or more.

[0050] In this case, for example, if the deformation is within the safety limit deformation angle, the situation where the lower corner part 10C2 of the load-bearing surface material 10 contacts the floor backing material 3 can be avoided, even if the load-bearing surface material 10 is deformed due to shaking. Thereby, the load-bearing surface material 10 including the gypsum board can maintain a proper seismic resistance. As a result, with the load-bearing wall S1 according to the present embodiment, the expected proper seismic resistance can be ensured, and the seismic resistance can be improved over the conventional.

[0051] <Embodiment 2> 　Next, a load-bearing wall S2 according to Embodiment 2 will be described. FIG. 4 is a front view of a load-bearing wall S2 according to Embodiment 2. The load-bearing wall S2 is configured of a plurality of load-bearing surface materials 101 to 104 fixed to a framework part 50.

[0052] The framework part 50 includes: a first principal post 51 and second principal post 52 arranged such that longitudinal directions thereof extending in the vertical direction D1 are mutually parallel; an upper principal lateral structural material 53 connected to an upper end of the first principal post 51 and upper end of the second principal post 52 and extending in the horizontal direction D2; and a lower principal lateral structural material 54 connected to a lower end of the first principal post 51 and lower end of the second principal post 52 and extending in the horizontal direction D2.

[0053] A first stud 55, second stud 56, and third stud 57, which are aligned in the horizontal direction D2, are provided between the first principal post 51 and second principal post 52. Upper ends of the first stud 55, the second stud 56, and the third stud 57 are connected to a lower surface of the upper principal lateral structural material 53. Lower ends of the first stud 55, the second stud 56, and the third stud 57 are connected to a lower surface of the lower principal lateral structural material 54. Note that connections between the members configuring the framework part 50 are performed in the same manner as connections between members of the framework part 5 in Embodiment 1; therefore, a detailed description is omitted in the present embodiment.

[0054] A first cross beam 58 is provided between the first principal post 51 and the first stud 55, and the first cross beam 58 extends in the horizontal direction D2 and connects the first principal post 51 and the first stud 55. A second cross beam 59 is provided between the first stud 55 and the second stud 56, and the second cross beam 59 extends in the horizontal direction D2 and connects the first stud 55 and the second stud 56. A third cross beam 60 is provided between the second stud 56 and the third stud 57, and the third cross beam 60 extends in the horizontal direction D2 and connects the second stud 56 and the third stud 57. A fourth cross beam 61 is provided between the third stud 57 and the second principal post 52, and the fourth cross beam 61 extends in the horizontal direction D2 and connects the third stud 57 and the second principal post 52. The first cross beam 58, the second cross beam 59, the third cross beam 60, and the fourth cross beam 61 are aligned in a straight line in the horizontal direction D2.

[0055] A floor backing material 62 is attached to an upper surface of the lower principal lateral structural material 54. Therefore, the floor backing material 62 is arranged at a position shifted, for example, to the upper principal lateral structural material 53 relative to the lower principal lateral structural material 54.

[0056] A first receiving material 63, a second receiving material 64, a third receiving material 65, and a fourth receiving material 66 are attached to the upper surface of a portion of the floor backing material 62 overlapping with the lower principal lateral structural material 54. The first receiving material 63 is positioned between the first principal post 51 and the first stud 55. The second receiving material 64 is positioned between the first stud 55 and the second stud 56. The third receiving material 65 is positioned between the second stud 56 and the third stud 57. The fourth receiving material 66 is positioned between the third stud 57 and the second principal post 52.

[0057] A first frame body part 71, a second frame body part 72, a third frame body part 73, and a fourth frame body part 74 are formed in the framework part 50. The first frame body part 71 is a quadrangular frame-like portion formed by a part of the first principal post 51, a part of the second stud 56, a part of the upper principal lateral structural material 53, the first cross beam 58 and second cross beam 59. The second frame body part 72 is a quadrangular frame-like portion formed by a part of the second stud 56, a part of the second principal post 52, a part of the upper principal lateral structural material 53, and the third cross beam 60 and fourth cross beam 61.

[0058] The third frame body part 73 is a quadrangular frame-like portion formed by a part of the first principal post 51, a part of the second stud 56, the first cross beam 58 and second cross beam 59, and a part of the lower principal lateral structural material 54. The fourth frame body part 74 is a quadrangular frame-like portion formed by a part of the second stud 56, a part of the second principal post 52, the third cross beam 60 and fourth cross beam 61, and a part of the lower principal lateral structural material 54.

[0059] Each of the plurality of load-bearing surface materials 101 to 104 include a first load-bearing surface material 101, a second load-bearing surface material 102, a third load-bearing surface material 103, and a fourth load-bearing surface material 104, each of which are quadrangular. The load-bearing surface materials 101 to 104 include gypsum boards. The load-bearing surface materials 101 to 104 may be gypsum boards with a lateral nail resistance of 500 N or more, for example, but are not particularly limited.

[0060] The first load-bearing surface material 101 is fixed to the first frame body part 71 and the second load-bearing surface material 102 is fixed to the second frame body part 72. The third load-bearing surface material 103 is fixed to the third frame body part 73 and the fourth load-bearing surface material 104 is fixed to the fourth frame body part 74. Fixture of each of the load-bearing surface materials 101 to 104 to the corresponding frame body parts 71 to 74 is the same as in Embodiment 1, and is performed by a plurality of the fastening members 11 not depicted.

[0061] In the present embodiment, the third load-bearing surface material 103 is fixed to at least a part of the first principal post 51 and a part of the second stud 56 corresponding to the pair of posts (first structural materials), as well as the "first cross beam 58 and second cross beam 59". The "first cross beam 58 and second cross beam 59" and a part of the lower principal lateral structural material 54 correspond to the pair of lateral structural materials (second structural materials). . Furthermore, the third load-bearing surface material 103 is not fixed to the lower principal lateral structural material 54 and forms a gap 80 with the floor backing material 62. The fourth load-bearing surface material 104 is fixed at least to a part of the second stud 56 and a part of the second principal post 52 corresponding to the pair of posts (first structural materials), as well as the "third cross beam 60 and fourth cross beam 61". The "third cross beam 60 and fourth cross beam 61" and a part of the lower principal lateral structural material 54 correspond to the pair of lateral structural materials (second structural materials) . Furthermore, the fourth load-bearing surface material 104 is not fixed to the lower principal lateral structural material 54 and forms a gap 81 with the floor backing material 62.

[0062] The width dimensions of the third load-bearing surface material 103 and fourth load-bearing surface material 104 are the same, and when the width dimension thereof is W, the dimension C2 in the vertical direction D1 of the gaps 80, 81 is set to be 0.5W × sin (rad / 30) or more. Note that the dimension C2 may also be determined in the present embodiment by using the equation "0.5W × sin (rad / 30) × (1 + β1) × β2" described in Embodiment 1. In other words, the dimensions of the gaps 80, 81 may be determined from the range of C2 where

[0063] The dimension C2 of the gaps 80, 81 may be set to 0.5W × sin (rad / 30) or more and 2W × sin (rad / 30) or less, 0.5W × sin (rad / 30) or more and 1.5W × sin (rad / 30) or less, or 0.5W × sin (rad / 30) or more and W × sin (rad / 30) or less. Furthermore, the dimension C2 of the gaps 80, 81 may be set to be W × sin (rad / 30) or more and 2W × sin (rad / 30) or less, or W × sin (rad / 30) or more and 1.5W × sin (rad / 30) or less.

[0064] In the load-bearing wall S2 according to Embodiment 2 described above, even if the third load-bearing surface material 103 and fourth load-bearing surface material 104 deform due to shaking, for example, a situation where the lower corner parts of the third and fourth load-bearing surface materials 103 and 104 contact the floor backing material 62 can be avoided if the deformation is within the safe limit deformation angle. Thereby, the third load-bearing surface material 103 and fourth load-bearing surface material 104, which include gypsum boards, can maintain proper seismic resistance. As a result, with the load-bearing wall S2 according to the present embodiment, the expected proper seismic resistance can be ensured, and the seismic resistance can be improved over the conventional.

[0065] <Embodiment 3> Next, a load-bearing wall S3 according to Embodiment 3 will be described. FIG. 5 is a front view of the load-bearing wall S3 according to Embodiment 3. The same codes are attached to component portions in the present embodiment that are similar to the component portions in Embodiment 1, and redundant descriptions are omitted.

[0066] The load-bearing wall S3 according to the present embodiment is of a wooden construction inner corner specification. The load-bearing wall S3 has a framework part 5' that forms a quadrangular frame by the pair of posts 1, 1 and the pair of lateral structural materials 2, 2, but the framework part 5' is not provided with the floor backing material 3 and receiving material 4 described in Embodiment 1. On the other hand, the framework part 5' is attached to a wall member 6 that extends in the face direction D3. The wall member 6 is attached to at least one of the pairs of lateral structural materials 2 so as to be arranged at a position shifted to the side of the other post 1 (right post 1 in FIG. 6) relative to one of the pairs of posts 1, 1 (left post 1 in FIG. 6). The wall member 6 forms an inner corner along with the pair of posts 1, 1 and pair of lateral structural materials 2, 2.

[0067] The load-bearing surface material 10 includes a gypsum board and is fixed to at least the pair of lateral structural materials 2, 2 and the right post 1 of the pair of posts 1, 1, but not to the left post 1. The load-bearing surface material 10 is fixed at least to the pair of lateral structural materials 2, 2 and the right post 1 by the fastening member 11, which is not depicted in the drawings. The load-bearing surface material 10 is fixed such that a gap 90 in the horizontal direction D2 is formed with the wall member 6. Code C3 in FIG. 6 indicates the dimension of the gap 90 in the horizontal direction D2. The gap 90 may be concealed by a decorative board or the like, or may be filled with a filler.

[0068] The dimension C3 of the gap 90 between the load-bearing surface material 10 and the wall member 6 is set to be 0.5W × sin (rad / 30) or more when the dimension (width dimension) of the load-bearing surface material 10 in the longitudinal direction (vertical direction D1) of the post 1 is W in the present embodiment. The dimension C3 of the gap 90 may be set to 0.5W × sin (rad / 30) or more and 2W × sin (rad / 30) or less, 0.5W × sin (rad / 30) or more and 1.5W × sin (rad / 30) or less, or 0.5W × sin (rad / 30) or more and W × sin (rad / 30) or less. Furthermore, the dimension C3 of the gap 90 may be set to be W × sin (rad / 30) or more and 2W × sin (rad / 30) or less, or W × sin (rad / 30) or more and 1.5W × sin (rad / 30) or less. Note that the dimension C3 may also be determined in the present embodiment by using the equation "0.5W × sin (rad / 30) × (1 + β1) × β2" described in Embodiment 1. In other words, the dimensions of the gap 90 may be determined from the range of C3 where

[0069] As described above, the load-bearing wall S3 according to Embodiment 3 includes: the framework part 5’ including the pair of lateral structural materials 2, 2 (corresponding to first structural material) arranged such that longitudinal directions thereof are mutually parallel, the pair of posts 1, 1 (corresponding to second structural material) intersecting the pair of lateral structural materials 2, 2 and arranged such that longitudinal directions thereof are mutually parallel, and the wall member 6 (corresponding to third structural material) provided at a position shifted to the other (right post 1) side (right side) relative to one (left post 1) of the pair of posts 1, 1 and extending in a direction (face direction D3) orthogonal to the longitudinal direction of the post 1 and longitudinal direction of the lateral structural material 2; and the load-bearing surface material 10 including a gypsum board, the load-bearing surface material 10 being fixed at least to the pair of lateral structural materials 2, 2 and right post 1 of the pair of posts 1, 1. Furthermore, the gap of 90 is formed between the load-bearing surface material 10 and the wall member 6. Furthermore, when the dimension of the load-bearing surface material 10 in the longitudinal direction of the post 1 is W, the dimension of the gap 90 is 0.5W × sin (rad / 30) or more.

[0070] In this case, even if the load-bearing surface material 10 is deformed due to shaking, for example, a situation where the lower corner part or upper corner part of the load-bearing surface material 10 positioned on the wall member 6 side contacts the wall member 6 can be avoided if the deformation is within the safety limit deformation angle. Thereby, the load-bearing surface material 10 including the gypsum board can maintain a proper seismic resistance. As a result, with the load-bearing wall S3 according to the present embodiment, the expected proper seismic resistance can be ensured, and the seismic resistance can be improved over the conventional.

[0071] <Examples> Next, evaluation results of the seismic resistance tests of the example and of a configuration that is substantially the same as that of the load-bearing wall according to the embodiments are described in contrast to a comparative example. The example is substantially the same structure as the load-bearing wall S2 according to Embodiment 2, and in testing for seismic resistance, the wall magnification of the example was calculated based on test results obtained by shaking the structure.

[0072] The structure according to the example is configured by providing a framework part 150 for testing with the first load-bearing surface material 101, second load-bearing surface material 102, third load-bearing surface material 103, and fourth load-bearing surface material 104 described in Embodiment 2. FIG. 6 is a longitudinal cross-sectional view of the framework part 150 for testing. The framework part 150 for testing is provided with a backing material 151 for testing (corresponding to third structural material in lower framework part for testing) that does not extend beyond the floor backing material 3 at the position of the floor backing material 3. However, other structures are the same as the framework part 50 in Embodiment 2, and common members are indicated by the same codes. FIG. 6 corresponds to a longitudinal cross-sectional view of the framework part 50 in Embodiment 2 when cut in the vertical direction in the center of the width direction, but the second stud 56 is not depicted.

[0073] As depicted in FIG. 6, the third load-bearing surface material 103 and fourth load-bearing surface material 104 were fixed such that a gap in the vertical direction D1 was formed therebetween with the backing material 151 for testing. Furthermore, the width dimension in the horizontal direction of the third load-bearing surface material 103 and fourth load-bearing surface material 104 was 900 mm, and dimension Ce of the gap between the third and fourth load-bearing surface materials 103 and 104 and the backing material 151 for testing was set at 20 mm. When 900 mm is substituted as W in "0.5W × sin (rad / 30)", 15.00 mm is calculated, and the 20 mm dimension Ce of the gap is larger than this value.

[0074] A gypsum board stipulated in JIS A 6901:2014 having a thickness of 9.5 mm and a lateral nail resistance of 500 N or more was used as the first load-bearing surface material 101, second load-bearing surface material 102, third load-bearing surface material 103 and fourth load-bearing surface material 104.

[0075] In the comparative example, the third load-bearing surface material 103 and fourth load-bearing surface material 104 were fixed to the framework part 150 for testing such that the dimension of a gap between the third and fourth load-bearing surface materials 103 and 104 and the backing material 151 for testing were 0 mm and 5 mm, respectively, but other configurations are the same as in the example.

[0076] Seismic resistance testing was conducted by manufacturing a framework part 150 for testing in a condition in which the lower principal lateral structural material 54 is fixed to a frame not depicted (first manufacturing step), then fixing the load-bearing surface materials 101 to 104 to the framework part 150 for testing (second manufacturing step), and then applying vibration (force) in the horizontal direction to the upper principal lateral structural material 53 (vibration step). The excitation pattern was based on the ministerial certification test for load-bearing walls in Japan.

[0077] In the test above, the following values were obtained for the examples and comparative example: i) yield resistance (Py), ii) value of ultimate resistance (Pu) corrected based on plasticity rate (μ), iii) value of 2 / 3 of the maximum resistance (Pmax), iv) resistance at shear deformation angle = 1 / 120 rad (for unloaded or loaded type). Furthermore, the wall magnification as a measure of seismic resistance is obtained by dividing the short-term allowable shear stress by 1.96 (kN / m). The smallest value of the above i) to iv) indices is selected as the short-term allowable shear stress. Note that the indices of i) to iv) above are defined in the "Allowable Stress Design of Wooden Framework Construction Houses (2017 Edition)" published by the Japan Housing and Wood Technology Center of Japan.

[0078] The specifically calculated wall magnification was 2.7 times for the example, 1.8 times for the comparative example with a gap of 0 mm, and 2.0 times for the comparative example with a gap of 5 mm. The wall magnification in the example is significantly greater than in the comparative examples. This is because the dimension Ce of the gap is set to 0.5W × sin (rad / 30) or more (W represents the width dimension of each of the third load-bearing surface material 103 and the fourth load-bearing surface material 104). The above test results confirm the effectiveness of the present invention. The wall magnification is an index specified in Article 46 of the Order for Enforcement of the Building Standards Act of Japan.

[0079] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various changes may be made to the embodiments described above.

[0080] S1, S2, S3: Load-bearing wall, 1: Post, (first structural material or second structural material), 2: Lateral structural material (first structural material or second structural material), 3: Floor backing material (third structural material), 4: Receiving material, 5, 5’: Frame part, 6: Wall member (third structural material), 10: Load-bearing surface material, 101: First load-bearing surface material, 102: Second load-bearing surface material, 103: Third load-bearing surface material, 104: Fourth load-bearing surface material, 10C1, 10C2: Lower corner part, 11: Fastening member, 20, 80, 81, 90: Gap, 50: Frame part, 51: First principal post, 52: Second principal post, 53: Upper principal lateral structural material, 54: Lower principal lateral structural material, 55: First stud, 56: Second stud, 57: Third stud, 58: First cross beam, 59: Second cross beam, 60: Third cross beam, 61: Fourth cross beam, 62: Floor backing material (third lateral structural material), 63: First receiving material, 64: Second receiving material, 65: Third receiving material, 66: Fourth receiving material, 71: First frame body part, 72: Second frame body part, 73: Third frame body part, 74: Fourth frame body part, 150: Framework part for testing, 151: Backing material for testing, D1: Vertical direction, D2: Horizontal direction, D3: Face direction, C1, C2, C3: Gap dimension

Claims

1. A load-bearing wall, comprising: 　　　a framework part including a pair of first structural materials arranged such that longitudinal directions thereof are mutually parallel, a pair of second structural materials intersecting the pair of first structural materials and arranged such that longitudinal directions thereof are mutually parallel, and a third structural material provided at a position shifted to the other side relative to one of the pairs of second structural materials and extending in a direction orthogonal to each of the longitudinal directions of the first and second structural materials; and 　　　a load-bearing surface material including a gypsum board, the load-bearing surface material being fixed at least to the pair of first structural materials and to the other of the pair of second structural materials, wherein 　　　a gap is formed between the load-bearing surface material and the third structural material, and 　　　when the dimension of the load-bearing surface material in the longitudinal direction of the second structural material is W, the dimension of the gap is 0.5W × sin (rad / 30) or more.

2. The load-bearing wall according to claim 1, which is a floor above bottom beam specification load-bearing wall, wherein 　　　the first structural materials are posts, 　　　the second structural materials are lateral structural materials, and 　　　the third structural material is a floor backing material.

3. The load-bearing wall according to claim 1, which is an inner corner specification load-bearing wall, wherein 　　　the first structural materials are lateral structural materials, 　　　the second structural materials are posts, and 　　　the third structural member is a wall member that forms an inner corner with the first and second structural materials.

4. The load-bearing wall according to any one of claims 1 to 3, wherein the gap is W × sin (rad / 30) or more.

5. The load-bearing wall according to any one of claims 1 to 3, wherein the gap is 2W × sin (rad / 30) or less.

6. A method for manufacturing a load-bearing wall including: 　　　a framework part including a pair of first structural materials arranged such that longitudinal directions thereof are mutually parallel, a pair of second structural materials intersecting the pair of first structural materials and arranged such that longitudinal directions thereof are mutually parallel, and a third structural material provided at a position shifted to the other side relative to one of the pairs of second structural materials and extending in a direction orthogonal to each of the longitudinal directions of the first and second structural materials; and 　　　a load-bearing surface material including a gypsum board, the load-bearing surface material being fixed at least to the pair of first structural materials and to the other of the pair of second structural materials, and 　　　a gap being formed between the load-bearing surface material and the third structural material, 　　　the method for manufacturing a load-bearing wall, comprising: 　　　a surface material dimension specifying step for specifying a dimension of the load-bearing surface material in the longitudinal direction of the second structural members as W; 　　　a gap dimension determining step for determining the dimension of the gap within a range of 0.5W × sin (rad / 30) or more; and 　　　an assembly step for fixing the load-bearing surface material to the framework part such that the dimension of the gap is the gap determined in the gap dimension determining step.

7. A method for manufacturing a load-bearing wall including: 　　　a framework part including a pair of first structural materials arranged such that longitudinal directions thereof are mutually parallel, a pair of second structural materials intersecting the pair of first structural materials and arranged such that longitudinal directions thereof are mutually parallel, and a third structural material provided at a position shifted to the other side relative to one of the pairs of second structural materials and extending in a direction orthogonal to each of the longitudinal directions of the first and second structural materials; and 　　　a load-bearing surface material including a gypsum board, the load-bearing surface material being fixed at least to the pair of first structural materials and to the other of the pair of second structural materials, and 　　　a gap being formed between the load-bearing surface material and the third structural material, 　　　the method for manufacturing a load-bearing wall, comprising: 　　　a surface material dimension specifying step for specifying a dimension of the load-bearing surface material in the longitudinal direction of the second structural members as W; 　　　a gap dimension determining step for determining the dimension of the gap within a range of 0.5W × sin (rad / 30) × (1 + β1) × β2 or more; and 　　　an assembly step for fixing the load-bearing surface material to the framework part such that the dimension of the gap is the gap determined in the gap dimension determining step.

Images