JP2020111916A - 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 base metal fixture 9 that is fixed to the foundation 2 and fixes 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 lower frame member whose lower surface height is equal to the lower end face of the column, and a structural face member fixed to at least the outdoor side surface of the column and the lower frame member, and fixed to a foundation, And a base metal member for fixing the lower frame member.

The lower end structure of the load bearing wall of the present invention is characterized in that the lower frame member is joined at an intermediate portion in the longitudinal direction to the upper surface of the base metal object.

The lower end structure of the load bearing wall of the present invention is characterized in that an L-shaped plate is fixed to a side surface of a column base portion of the column, and an end portion of the lower frame member is joined to the L-shaped plate.

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 connecting portion, and the base metal article has the same shape as the base portion.

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 columns and whose lower surface has the same height as the lower end face of the columns is fixed to the base metal member fixed to the foundation. Therefore, since the horizontal load applied to the lower frame member in the axial direction is received by the base metal member fixed to the foundation, it is possible to suppress the horizontal load from being applied to the column base of the column from the lower frame member. Then, the column base metal member receives the pulling force applied to the column base portion, and the base metal member receives the horizontal load applied to the lower frame member, so that the column and the column base metal member and the lower frame member and the base metal member are joined together. The required proof stress can be made clear. 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, since the middle of the lower frame member is joined to the upper surface of the base metal object, the horizontal load applied in the axial direction of the lower frame member is fixed to the base. Since it is received by the hardware, it is possible to prevent horizontal load from being applied to the column base of the column from the lower frame member. Then, the base metal piece is arranged in the center of the lower frame member, so that the base metal piece is arranged in the middle of the pair of column base metal pieces, and the load transmitted from the load bearing wall to the foundation through the anchor bolts can be dispersed.

According to the lower end structure of the load bearing wall of the present invention, the L-shaped plate is fixed to the side surface of the column base of the column, and the end of the lower frame member is joined to the L-shaped plate. It is fixed to the base metal and both ends are joined to the L-shaped plate respectively, which facilitates positioning during construction of the lower frame material, and the lower frame material has sufficient strength as a base for the structural face material. Can have. Since the intermediate portion is fixed to the base metal member, a horizontal load applied in the axial direction of the lower frame member can be received by the base metal member.

According to the lower end structure of the load-bearing wall of the present invention, since the base part and the base metal part of the column base metal product have the same shape, the base metal part can be a base metal product only by removing the connection part of the column base metal product, and the manufacturing cost of the member Can be reduced.

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 column base metal fittings and base metal fittings 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, an embodiment of the lower end structure 1 of the load bearing wall of the present invention will be described with reference to FIGS. 1 to 7. As shown in FIG. 5, the load-bearing wall 4 of the lower end structure 1 of the load-bearing wall of the present embodiment includes a pair of column bases 3 fixed to the foundation 2 and a pair of columns 5 fixed to the column bases 3. A horizontal member 6 such as a beam erected on the pillar head 52 of the pillar 5, a lower frame member 7 arranged between the pillar bases 51 of the pillar 5, and the base 2 between the pair of pillar bases 3. The base metal member 9 which is fixed and fixes the lower frame member 7 is provided. 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. 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 base 2 of the present embodiment is an outer peripheral rising portion of the base 2, and although not shown, the lower part is buried below the ground line, and a reinforcing bar (not shown) is buried 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, 500 mm to fix the column base metal piece 3 and the base metal piece 9. As shown in FIG. 1, the anchor bolt 11 has a flange-shaped portion embedded in the foundation 2 so as to resist the pulling force generated in the column base 51 and the horizontal force generated in the lower frame member 7. Although the enlarged diameter portion 12 is provided, for example, the portion embedded in the foundation 2 may be curved in a J shape, an L shape, or the like. 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(A), the pillar pedestal 3 is formed with a lower plate 31 having a fixing hole 30 into which the anchor bolt 11 is inserted, and a cross-shaped cross section that projects upward from the lower plate 31. A base portion 34 having a connecting leg portion 32 and an upper plate 33 which is a horizontal flat plate fixed to the upper end of the connecting leg portion 32, and a flat plate-like shape projecting upward from the base portion 34. The connection portion 36 is formed by arranging three drift holes 35 for fixing the portion 51. 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 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 lower frame member 7 is a wooden square member, and as shown in FIGS. 1 and 2, both ends thereof have a length such that they are brought into contact with the column bases 51 of the pair of columns 5, respectively. An intermediate hole 70 is formed in the lower frame member 7 so as to vertically penetrate therethrough at the center in the length direction. Both ends of the lower frame member 7 are fixed to the column base portion 51 by the L-shaped plates 71, and the center in the length direction is fixed to the base metal member 9.

As shown in FIG. 3(B), the base metal fitting 9 is arranged in the center at a distance from the pair of column base metal fittings 3 at equal intervals. The base metal 9 includes a lower plate 92 having a fixing hole 91 into which the anchor bolt 11 is inserted, a connecting leg 93 having a cross-shaped cross section and protruding upward from the lower plate 92, and a connecting leg 93. It has an upper plate 94 which is a horizontal flat plate fixed to the upper end, and has almost the same shape as the base portion 34 of the pedestal metal fitting 3. The lower plate 92 of the base metal fitting 9 is formed with a fixing hole 91 into which the anchor bolt 11 for fixing the base 2 is inserted, and the upper plate 94 of the base metal fitting 9 is fixed with the fixing hole 91 of the lower plate 92 from above. An insertion hole 95 having a diameter larger than that of the fixing hole 91 is formed at a position where the insertion holes 95 are overlapped with each other when viewed.

Further, the base metal 9 has a connection hole 90 formed at a position different from the insertion hole 95 of the upper plate 94. The connection bolt 72 is inserted into the intermediate hole 70 and the connection hole 90 formed in the lower frame member 7, and the connection nut 73 is screwed to fix the lower frame member 7 and the base metal member 9.

The L-shaped plate 71 is a steel angle, and contacts the side surface of the column base 51 and the upper surface of the end of the lower frame member 7 in the present embodiment. And the upper surface of the end portion of the lower frame member 7 are fixed.

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. As shown in FIG. 4, in a state in which the connecting portion 36 is inserted into the slit 53 of the column base 51, the drift hole 35 of the connecting portion 36 and the horizontal through hole 54 of the column base 51 are aligned, and a drift (not shown) is formed. The pin is inserted into the horizontal through hole 54 and the drift hole 35, and the column base 51 and the column base metal fitting 3 are joined. Note that, in FIG. 4, the structural surface material is omitted for convenience of illustration.

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 the horizontal member 6. In this embodiment, the beam wins are settled, and the upper end of the pillar 5 and the lower surface of the horizontal member 6 are joined, but in the case of a pillar win such as a through pillar, the side end surface of the horizontal member 6 and the pillar are joined. The side surface of 5 may be joined.

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 column base portion 51 of the conventional bearing wall 4a in FIG. 7, the base metal member 9 is not formed, and the lower frame member 7 is joined to the column base portion 51 only by the L-shaped plate 71. When the column base 51 is present, two forces, that is, the vertical pulling force and the horizontal shearing force transmitted from the axial direction of the lower frame member 7, are applied to the column base 51, and the stress that the column base 51 can bear is extremely high. It becomes low. Therefore, for example, it is necessary to take measures such as changing the load-bearing wall 4 on the third floor to a low-performance wall, and it is necessary to dispose the load-bearing wall 4 at another location in order to compensate for the insufficient wall amount. The degree of freedom of the plan is reduced, such as the number of places where parts can be installed decreases.

However, in the column base portion 51 of the present embodiment shown in FIG. 6, since the center of the lower frame member 7 is fixed to the base 2 by the base metal fitting 9, the axial force generated in the lower frame member 7 is the base. 2, the horizontal shearing force transmitted to the column base 51 from the axial direction of the lower frame member 7 can be reduced. The end portion of the lower frame member 7 of the present embodiment is joined to the side surface of the column base portion 51 by the L-shaped plate 71, but by reducing the horizontal shearing force transmitted to the column base portion 51, the column base portion 51 is reduced. The load applied in the shearing direction can be reduced, and the high-performance bearing wall 4 having a larger shearing force can be arranged. Therefore, the high-performance load bearing walls 4 can be arranged, for example, in the upper and lower three stages, and the degree of freedom in planning such as installing a large opening can be increased.

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 surface material 9 Base metal fitting 51 Pillar base 71 L-shaped plate

Claims (4)

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 base metal fixture fixed to the foundation and fixing the lower frame member,
A lower end structure of a load-bearing wall, comprising: 2. The lower end structure of a load bearing wall according to claim 1, wherein the lower frame member is joined to the upper surface of the base metal object at the middle in the length direction. The lower end structure of the load bearing wall according to claim 2, wherein an L-shaped plate is fixed to a side surface of a column base portion of the column, and an end portion of the lower frame member is joined to the L-shaped plate. 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 said base metal thing is the same shape as the said base part, The lower end structure of the bearing wall in any one of Claim 1 to 3 characterized by the above-mentioned.

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