JP2020111915A - Lower end structure of bearing wall - Google Patents

Abstract

To provide a lower end structure of a bearing wall capable of reducing the load in a horizontal shear direction applied to a column base part.SOLUTION: A lower end structure 1 of a bearing wall includes: a pair of pieces of column base hardware 3 that are fixed to a foundation 2 at a distance from each other; a pair of columns 5 in which a column base part 51 is fixed to the column base hardware 3; a lower frame member 7 that is placed between the column base parts 51 of the columns 5 and in which the height of the lower surface is the same as the lower end surface of the columns 5; a structural panel 8 that is fixed to at least the column 5 and the outside of the lower frame member 7; and a lower frame fixing plate 9 that is formed in the pair of pieces of column base hardware 3 and fixes the end of the lower frame member 7.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lower end structure of a load-bearing wall, and particularly to a base having a pair of pillars whose pillar bases are joined on a foundation and a lower frame member horizontally arranged between the pillar bases of the pillars. The present invention relates to a lower end structure of a load bearing wall to which a structural face material is attached.

Conventionally, a structural surface is provided on the outdoor side surface of a wooden frame formed by a base provided on a foundation, a pair of pillars erected on the base, and a beam erected on the upper ends of the pillars. A bearing wall in which a material is fixed with a nail or the like is known (for example, Patent Document 1). When a horizontal shearing force is applied to a building, each load-bearing wall arranged in the building resists the horizontal shearing force, and the pulling direction force is applied to the column base of one of the columns forming the load-bearing wall, and the other A compressive force is applied to the column base of the column. When the load bearing walls are arranged vertically, the pulling force and compression force applied to the load bearing walls on the upper floor are also transmitted to the load bearing walls on the lower floor. A large pull-out force and a large compressive force are applied to the column bases of No.

Then, to prevent the column base from being pulled out by the pulling force applied to the column base, connect the column base metal to the anchor bolt partially embedded in the foundation, and connect the column base of the column to the column base metal. The structure is known. In such a structure, since the wooden base is not used for the connection between the column base and the foundation, the stress against the pulling force to the column base can be increased. Further, among such column pedestals, there has been proposed one in which plates are respectively extended laterally and the ends of the base are connected (for example, Patent Document 2).

JP, 2012-202112, A JP, 2017-20236, A

By the way, the base provided on the foundation is arranged for the purpose of supplementing the construction accuracy of the foundation. Therefore, if the foundation construction accuracy is high, it is not always necessary to provide a foundation. When the base is not provided, the part where the base is conventionally installed can be made a large gap, which is advantageous for ventilation under the floor and inside the wall, and the gap blocks the path of the ant path. Therefore, the ant repellency can be enhanced.

Even if the base is not provided as described above, it is necessary to dispose the lower frame material, which is the base of the lower end portion of the structural surface material, between the column bases. The lower frame member is installed between the column bases, and both ends thereof are fixed to the side surfaces of the column bases, respectively. When horizontal shear force is applied to the building when the lower frame material is fixed to the side surface of the column base in this way, pulling force is applied to the column base part of the column, and also horizontal shear force from the lower frame material. It will be added to the pillar base. Therefore, a load in the pull-out direction and a load in the shearing direction are simultaneously applied to the column base, and there is a problem that the load that can be carried by the column base is extremely reduced as compared with the case where the load is one direction.

Therefore, it is an object of the present invention to provide a lower end structure of a load bearing wall that can reduce the load in the horizontal shearing direction applied to a column base.

The lower end structure of the load bearing wall of the present invention includes a pair of pillar bases fixed to a foundation with a space therebetween, a pair of pillars having a column base fixed to the pillar base, and a pillar base of the pillar. And a pair of column bases, a lower frame member having a lower surface whose height is equal to the lower end face of the column, a structural face member fixed to at least the outdoor side surface of the column and the lower frame member, And a lower frame fixing portion which is formed on a metal member and which fixes the end portion of the lower frame member.

In the lower end structure of the load bearing wall of the present invention, the column base metal fitting is formed by a base portion on which the lower end surface of the column is placed and protruding upward from the base portion, and connects the column base portion. And a connection part, wherein the lower frame fixing part is a flat plate lower frame fixing plate formed by projecting in a horizontal direction from the upper surface of the base part, and the lower frame material is the lower frame material. It is characterized in that the lower surface of the end portion is joined in contact with the upper surface of the lower frame fixing plate.

The lower end structure of the load bearing wall of the present invention is characterized in that a gap is formed between the end portion of the lower frame member and the column.

According to the lower end structure of the load bearing wall of the present invention, the lower frame member which is arranged between the column bases of the column and whose lower surface has the same height as the lower end face of the column is formed on the column base metal member fixed to the foundation. Since it is fixed to the lower frame fixing part, the horizontal load applied in the axial direction of the lower frame material is applied from the lower frame material to the column base part of the column through the lower frame fixing part and the column pedestal hardware. Can be suppressed. In addition, since the lower end surface of the pillar is provided with a column base metal fitting between the foundation and the pillar base metal, it is arranged at a distance above the foundation, and the lower surface of the lower frame member is arranged at the same height as the lower end surface of the pillar. Therefore, a space is provided between the foundation and the lower frame member, and this space blocks the dove road, thereby improving the ant-proof property.

According to the lower end structure of the load-bearing wall of the present invention, the lower frame fixing portion is the lower frame fixing plate that horizontally projects from the base of the pillar pedestal, and the lower frame material has the lower surface of the end portion of the lower frame material as Since it is joined in contact with the upper surface of the frame fixing plate, the horizontal load applied in the axial direction of the lower frame material is received by the lower frame fixing plate fixed to the foundation via the base part, so the column base It is possible to suppress horizontal load from being applied to the portion from the lower frame member. In addition, by placing the end portion on the lower frame fixing plate when constructing the lower frame member, the lower frame member is arranged between the column bases and the lower frame member and the lower frame fixing plate are arranged. Since it is fixed, the lower frame member can be easily positioned and can be easily and accurately constructed.

According to the lower end structure of the load bearing wall of the present invention, since the gap is formed between the end of the lower frame member and the column, the horizontal load applied in the axial direction of the lower frame member is directly transmitted to the column base of the column. Therefore, it is possible to prevent horizontal load from being applied to the column base of the column from the lower frame member.

The partially omitted front view explaining the lower end structure of a load bearing wall. The partially omitted perspective view explaining the lower end structure of a load bearing wall. The perspective view which shows the form of the pillar metal fitting used for the lower end structure of a load bearing wall. FIG. 3 is a partially omitted exploded perspective view illustrating a lower end structure of a load bearing wall. The front view which shows the structure of the bearing wall in which the lower end structure of the bearing wall is formed. The front view and the abbreviated enlarged view for explaining the load of the load bearing wall when a horizontal load is applied to a three-story building in which the load bearing wall having the lower end structure of the load bearing wall of the present invention is arranged. The front view and the abbreviated enlarged view which explain the load of the bearing wall when a horizontal load is applied to the building of three floors in which the bearing wall having the lower end structure of the conventional bearing wall is arranged.

Hereinafter, a lower end structure 1 of a load bearing wall according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. As shown in FIG. 5, the load-bearing wall 4 in the lower end structure 1 of the load-bearing wall of the present embodiment has a pair of column base metal parts 3 fixed to the foundation 2 and a column base part 51 fixed to the column base metal part 3. It is provided with a pair of pillars 5, a horizontal member 6 such as a beam erected on a pillar head 52 of the pillar 5, and a lower frame member 7 arranged between the pillar leg portions 51 of the pillar 5. Then, the load bearing wall 4 is obtained by fixing the structural face material 8 to the outdoor side surface of the rectangular wooden frame set 10 formed by the pair of pillars 5, the horizontal member 6, and the lower frame member 7 with the nail 80 or the like. , Bears the horizontal shear force. Further, the lower frame member 7 is fixed at its end portion to a lower frame fixing plate 9 as a lower frame fixing portion. In each drawing, the structural face material 8 is represented by a chain line for convenience of illustration, and members originally hidden by the structural face material 8 are represented by solid lines.

The foundation 2 of the present embodiment is a foundation rising portion on the outer periphery of the building, and although not shown, the lower portion is embedded below the ground line, and a reinforcing bar (not shown) is embedded inside. Further, as shown in FIG. 1, an anchor bolt 11 is embedded in the foundation 2 so that a part thereof projects upward from the top end. The anchor bolts 11 are embedded in the foundation 2 at a pitch of, for example, 1 m in order to fix the column base metal piece 3. As shown in FIG. 1, the anchor bolt 11 has a flange-shaped enlarged diameter portion 12 in a portion embedded in the foundation 2 so as to resist the pulling force generated in the column base portion 51. There is. The anchor bolt 11 may have a J-shaped or L-shaped curved portion embedded in the foundation 2 as long as it can resist the pulling force generated in the column base 51. The anchor bolt 11 is provided with a bolt groove in a portion projecting upward from the top end of the base 2, and the fixing nut 13 is screwed to fix the column base metal piece 3.

As shown in FIG. 3, the pillar pedestal 3 includes a lower plate 31 having a fixing hole 30 into which the anchor bolt 11 is inserted, and a connecting leg portion having a cross-shaped cross section and protruding upward from the lower plate 31. 32 and a base part 34 having an upper plate 33 which is a horizontal flat plate fixed to the upper ends of the connecting leg parts 32, and a flat plate-like shape projecting upward from the base part 34. It is provided with a connecting portion 36 formed by arranging three drift holes 35 for fixing. An insertion hole 37 having a larger diameter than the fixing hole 30 is formed in the upper plate 33 of the base portion 34 at a position overlapping the fixing hole 30 of the lower plate 31 when viewed from above, and the fixing nut 13 is attached to the anchor bolt 11. A tool (not shown) can be inserted when fastening. The column base metal fitting 3 is fixed to an anchor bolt 11 protruding above the top end of the foundation 2 at a pitch of 1 m, for example.

The column base metal fitting 3 is formed with a flat plate-shaped lower frame fixing plate 9 protruding in the horizontal direction so as to be continuous with the upper plate 33. The lower frame fixing plate 9 has a connecting hole 90 for connecting the end portion of the lower frame member 7. The lower frame fixing plate 9 is integrally formed with the column base metal piece 3, and is fixed to the foundation 2 via the base portion 34 of the column base metal piece 3. The lower frame fixing portion of the present invention corresponds to the lower frame fixing plate 9 of this embodiment.

The lower frame member 7 is a wooden square member, and as shown in FIGS. 1 and 2, both ends of the lower frame member 7 are placed and erected on the upper surface of the lower frame fixing plate 9, respectively. A through hole 70 is formed at an end of the lower frame member 7, and the lower frame member 7 is arranged so that the connecting hole 90 of the lower frame fixing plate 9 and the through hole 70 of the lower frame member 7 are aligned with each other. .. Then, as shown in FIG. 4, in a state where the lower surface of the lower frame member 7 and the upper surface of the lower frame fixing plate 9 are in contact with each other, the joining bolt 71 is attached from below the lower frame fixing plate 9 to the connecting hole 90 and the through hole. The lower frame fixing plate 9 and the lower frame member 7 are joined by being inserted into 70 and fastened from above by a joining nut 72. The lower frame member 7 is formed shorter than the distance between the pair of pillars 5, and the end portion of the lower frame member 7 does not contact the side surface of the pillar 5 and a gap is formed between the lower frame member 7 and the pillar 5. ing. Note that, in FIG. 4, the structural surface material is omitted for convenience of illustration.

In the pillar 5, a slit 53 into which the connecting portion 36 of the pillar pedestal 3 can be inserted is formed in the pillar pedestal 51 from the lower end upward, and penetrates from one side surface of the pillar pedestal 51 to the other side surface. Thus, three horizontal through holes 54 orthogonal to the slit 53 are formed. With the connecting portion 36 inserted in the slit 53 of the column base portion 51, the drift hole 35 of the connecting portion 36 and the horizontal through hole 54 of the column base portion 51 are aligned, and the drift pin (not shown) is connected to the horizontal through hole 54 and The column base 51 and the column base metal fitting 3 are joined by being inserted into the drift hole 35.

The end portion of the lower frame member 7 fixed to the lower frame fixing plate 9 and the column base portion 51 of the column 5 joined to the connecting portion 36 of the column base metal fitting 3 are arranged so as to be separated from each other as described above. Therefore, a gap is formed between the end of the lower frame member 7 and the column 5. Since the lower frame member 7 is fixed to the foundation 2 via the lower frame fixing plate 9 and the base portion 34 of the column base metal member 3, the horizontal shearing force generated in the axial direction of the lower frame member 7 should be received by the foundation 2. Therefore, the load is not transmitted from the lower frame member 7 to the column base portion 51. Therefore, since the column base 51 only needs to calculate the necessary strength in consideration of the load in the pulling direction, the stress that the column base 51 can bear can be increased. When the performance of the bearing wall 4 is increased, the load in the pulling-out direction of the column base 51 increases, but as described above, the column base 51 is configured so that no force is applied in the horizontal shearing direction. The performance of can be improved.

Further, since a space is provided between the top end of the base 2 and the lower surface of the lower frame member 7, the dovetail is blocked by this space, and the ant-proof property can be enhanced.

The horizontal member 6 is, for example, a wooden beam provided between the first floor and the second floor of the building. An unillustrated stake fitting is provided on the stilt head 52 of the stanchion 5 and is joined to a wooden beam. In this embodiment, the beam wins are settled, and the upper end of the column 5 and the lower face of the beam are joined, but in the case of a column win like a through column, the side end face of the beam and the side face of the column 5 are May be joined together.

As described above, the pair of pillars 5, the horizontal member 6, and the lower frame member 7 form the rectangular wooden frame set 10. Then, the structural face material 8 is fixed to the outdoor side surface of the wooden frame assembly 10 with the nails 80 or the like to form the bearing wall 4. The structural face material 8 is, for example, a plywood, and nails 80 are fixed at a pitch of 150 mm to the wooden framing set 10 as a base. The load bearing wall 4 resists the horizontal shearing force applied to the building and suppresses deformation, so that the horizontal shearing force is converted into the pulling force in the axial direction of the pillar 5, and the horizontal member 6 and the lower member of the upper frame of the load bearing wall 4 are A horizontal axial force is applied to the frame member 7.

For example, as shown in FIG. 6, in a case where a high-performance bearing wall 4 having a large horizontal shearing force that can be borne in a three-story building is continuously formed in three steps, the upper floor The pulling force generated in the column 5 is also transmitted to the lower floor, and a relatively large pulling force is generated in the column base portion 51 of the column 5 on the first floor. At this time, an axial force is generated in the lower frame member 7. Therefore, as shown in the conventional bearing wall 4a of FIG. 7, for example, when the lower frame member 7 is joined to the column base 51 via the L-shaped plate 14, the vertical pulling force and the lower frame Two forces of the horizontal shearing force transmitted from the axial direction of the material 7 are applied to the column base 51, and the stress that the column base 51 can bear becomes extremely low. Therefore, it is necessary to take measures such as changing the load bearing wall 4a on the third floor to a low performance one. In this case, it becomes necessary to dispose the load bearing wall 4a at another location in order to compensate for the insufficient wall amount, and the number of locations where the opening can be installed decreases.

However, in the column base 51 of the present embodiment shown in FIG. 6, the end portion of the lower frame member 7 is joined to the lower frame fixing plate 9, and the lower frame fixing plate 9 is the base portion of the column base metal fitting 3. Since it is fixed to the base 2 via the base 34, the axial force generated in the lower frame member 7 is received by the base 2 via the lower frame fixing plate 9 and the base portion 34, and The horizontal shearing force transmitted from the axial direction of the lower frame member 7 is not transmitted. In particular, since a gap is formed between the end portion of the lower frame member 7 and the column base portion 51 of this embodiment, the horizontal force in the axial direction of the lower frame member 7 is not transmitted to the column base portion 51. .. Therefore, it is possible to design the pulling force generated in the column base 51 and the horizontal force in the axial direction of the lower frame member 7 completely separated. Further, since the column base 51 is not excessively burdened, the high-performance bearing wall 4 can be arranged, for example, in the upper and lower three stages, and the degree of freedom of the plan such as setting a large opening can be increased. it can.

It goes without saying that the embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope of the idea of the present invention.

The lower end structure 1 of the load bearing wall according to the present invention is suitable, for example, as the lower end structure 1 of the load bearing wall of a building in which a plurality of load bearing walls 4 are vertically arranged.

1 Lower end structure of load-bearing wall 2 Foundation 3 Pillar pedestal 4 Load-bearing wall 5 Pillar 7 Lower frame material 8 Structural face material 9 Lower frame fixing plate (lower frame fixing part)

Claims (3)

A pair of pillar pedestals that are fixed to the foundation with a gap between them,
A pair of pillars in which the pillar base is fixed to the pillar base metal fittings,
A lower frame member that is arranged between the column bases of the columns, and the height of the lower surface thereof is equal to the lower end face of the columns,
At least a structural face material fixed to the outdoor side surface of the pillar and the lower frame member,
A lower frame fixing portion that is formed on the pair of column pedestals and fixes an end portion of the lower frame member,
A lower end structure of a load-bearing wall, comprising: The pillar pedestal includes a base portion on which the lower end surface of the pillar is placed, and a connecting portion that is formed so as to project upward from the base portion and that connects the pillar base portion,
The lower frame fixing portion is a flat plate lower frame fixing plate formed by projecting horizontally from the upper surface of the base portion,
The lower end structure of the load bearing wall according to claim 1, wherein the lower frame member is joined in a state where a lower surface of an end portion of the lower frame member is in contact with an upper surface of the lower frame fixing plate. The lower end structure of the load bearing wall according to claim 1 or 2, wherein a gap is formed between an end portion of the lower frame member and the column.

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