JP2021181712A - Column base structure - Google Patents

Abstract

To provide a column base structure with which forgetting to mount and a loss of a metal plate are prevented, which can correctly and easily adjust a level of a piece material, and with which a base plate portion is easily installed at a set level.SOLUTION: A column base structure 1 comprises: a column portion 3; a base plate portion 5 provided at a lower end of the column portion 3 and fixed to a foundation 2 by an anchor bolt; and a piece material 6 installed on the foundation 2 and supporting the base plate portion 5. The piece material 6 includes a mortar 9 and a metal plate 10 disposed on the mortar 9. The metal plate 10 is provided so as to be adjustable in height via a support shaft 12 standing upwardly from the foundation 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a column base structure in which a base plate portion provided at the lower end of a column portion is fixed to a foundation by anchor bolts and the base plate portion is supported by a piece material installed on the foundation.

At the joints between columns such as steel columns and foundations, it is common to fix the base plate portion provided at the lower end of the columns to the foundation with anchor bolts.
In such a column base structure, it is necessary to secure sufficient rigidity at the above-mentioned joints to withstand the bending moment in the vertical plane generated in the column during an earthquake or the like, which is a factor of cost increase.

Therefore, as in the column base structure described in Patent Document 1, the base plate is supported by the piece material installed on the foundation, and a gap is formed between the base plate and the foundation around the piece material to form a pillar. It has been proposed that when a bending moment is generated, the base plate is allowed to be rotationally deformed and the above-mentioned joints behave like a pin structure to reduce the proof stress required for the joints and reduce the cost. ..
In such a column base structure, not only the size of the piece material is small and the pressure per unit area is large, but also the upper end corner of the piece material is the center of rotation of the base plate, so the piece made of only mortar is used as the material. The material is easily damaged due to the large force applied locally. In order to prevent this, Patent Document 1 discloses a technique of stacking a metal plate on a mortar to form a piece material.

Japanese Unexamined Patent Publication No. 2018-159190

Conventionally, in order to install a piece material as described in Patent Document 1, a mortar before curing is placed on a foundation, and a metal plate is stacked after the mortar is cured.
However, if the piece material is formed by such a method, there is a risk that the metal plate may be forgotten to be placed, or may be lost or misaligned after being placed. In addition, it was difficult to adjust the level of the upper surface of the piece material, and there was a concern that the metal plate would sink depending on the softness of the mortar.

The present invention has been made in view of the above problems, and it is possible to prevent the metal plate from being forgotten or lost, to adjust the level of the piece material accurately and easily, and to install the base plate portion at a set level. The purpose is to provide an easy-to-use column base structure.

The invention according to claim 1 of the present application includes a pillar portion, a base plate portion provided at the lower end of the pillar portion and fixed to the foundation by anchor bolts, and a piece material installed on the foundation to support the base plate portion. The piece material is a column base structure including a mortar and a metal plate arranged on the mortar, and the metal plate is height-adjustable via a support shaft standing above the foundation. It is a column base structure characterized by being provided in.

The invention according to claim 2 of the present application is characterized in that the support shaft has a male screw portion, and the male screw portion is screwed into the female screw portion provided on the metal plate. It is a column base structure of.

The invention according to claim 3 of the present application is the column base structure according to claim 2, wherein the support shaft is erected on a base installed on the base.

In the invention according to claim 4, three female threaded portions are formed on the metal plate along a circle centered on the center of the metal plate at equal intervals, and the male threads of the support shaft are formed on the female threaded portions at equal intervals. The column base structure according to claim 2, wherein the portions are screwed together.

The pillar according to claim 1 or 2, wherein the invention according to claim 5 is characterized in that the anchor bolt is attached and the support shaft is erected on an anchor frame embedded in the foundation. It is a leg structure.

According to the present invention, after adjusting the height of the metal plate with respect to the support shaft, the mortar is filled between the metal plate whose height is determined and the foundation, so that the metal plate is placed on the hardened mortar. Compared to piece material, high construction accuracy and strict softness are not required for mortar, and accurate level adjustment of piece material can be easily performed. As a result, the base plate part is installed at the set level. Cheap.
In addition, there is no concern that the metal plate placed on the mortar will be lost or forgotten to be placed, and the occurrence of construction mistakes can be suppressed. Further, the misalignment of the metal plate can be prevented.

The vertical sectional view of the column base structure which shows the 1st Embodiment. The cross-sectional view of the column base structure which shows the 1st Embodiment. An exploded perspective view of a metal plate, a support shaft, and a substrate according to the first embodiment. An exploded perspective view of the metal plate and the support shaft according to the second embodiment. The bottom view of the metal plate and the support shaft which concerns on 2nd Embodiment. The vertical sectional view of the column base structure which shows the 3rd Embodiment. The plan view of the anchor frame which concerns on 3rd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Needless to say, the present invention is not limited to the embodiments described below.

[First Embodiment]
1 to 3 show a first embodiment of the present invention. 1 and 2 show a column base structure, and FIG. 3 shows a metal plate, a support shaft and a base.

The column base structure 1 is provided on a concrete foundation 2, and has a column portion 3, a concrete 4, a base plate portion 5, a piece material 6, and the like. In this column base structure 1, when a bending moment in the vertical plane is generated in the column portion 3, the base plate portion 5 is rotationally deformed, so that the joint portion between the column portion 3 and the foundation 2 functions as a pin structure.

The pillar portion 3 is, for example, a pillar material of a prism, and is formed of a square steel pipe or the like.
A base plate portion 5 is provided at the lower end of the pillar portion 3. The base plate portion 5 is a steel plate-shaped member having a substantially rectangular flat surface, and the lower end of the pillar portion 3 is welded to the center portion of the upper surface. The base plate portion 5 is provided with a through hole 51 and a slit 52. The slit 52 is formed so as to avoid the position of the pillar portion 3.

Anchor bolts 7 are embedded in the foundation 2. The upper end portion of the anchor bolt 7 protrudes from the foundation 2 and is inserted into the through hole 51 of the base plate portion 5. The nut 8 is tightened to the protruding portion of the anchor bolt 7 protruding from the through hole 51. For example, a double nut is used for the nut 8, but the nut 8 is not limited to this.

The slit 52 is formed in a substantially L shape in the vicinity of each anchor bolt 7. That is, the slit 52 is cut inward from each outer side of the base plate portion 5, and is formed so as to extend from the tip thereof in parallel with each outer side of the base plate portion 5. Each anchor bolt 7 (through hole 51) is surrounded by a slit 52 and an outer side of the base plate portion 5 from three sides.
Since the anchor bolt 7 is surrounded by the slit 52 and the outer side of the base plate portion 5, a deformable portion is formed in the base plate portion 5 fixed by the anchor bolt 7.

A piece material 6 is provided between the base plate portion 5 and the foundation 2. The piece lumber 6 is provided to support the base plate portion 5 when the pillar portion 3 is constructed.
The piece lumber 6 is arranged near the central portion of the base plate portion 5, and a gap 20 is formed between the base plate portion 5 and the foundation 2 below the base plate portion 5 on the outer peripheral side of the base plate portion 5. As a result, the amount of rotational deformation of the base plate portion 5 can be increased with a simple configuration. An elastic member such as a sponge may be arranged in the gap 20.

The piece material 6 includes a mortar 9 and a metal plate 10 arranged on the mortar 9.
In the present embodiment, the metal plate 10 is a disk made of steel or the like and having a thickness of about 9 mm to 40 mm, and the diameter thereof is such that a gap 20 is formed on the lower surface of the base plate portion 5. Further, in the center of the metal plate 10, a penetrating screw hole serving as a female screw portion 11 or a bottomed screw hole having an open lower end is formed.
A male screw portion 12a formed at the upper end portion of the support shaft 12 is screwed into the female screw portion 11. The support shaft 12 is erected at the center of the upper surface of the metal base 13. Therefore, the metal plate 10 can be moved up and down with respect to the support shaft 12 by rotating it.
The thickness of the support shaft 12 and the area of the base 13 shall be such that the metal plate 10 can be stably supported.

When constructing the column base structure 1, before building the column portion 3, the base 13 on which the support shaft 12 is erected is placed on the foundation 2 at a position corresponding to the central portion of the base plate portion 5. The base 13 is fixed to the base 2 with an adhesive or a fixture pre-embedded in the base. The base 13 may be simply placed without being fixed to the base 2.
Next, the metal plate 10 is rotated to move up and down with respect to the support shaft 12, and the height from the upper surface of the foundation 2 to the upper surface of the metal plate 10 is set from the foundation 2 set at the time of design to the lower surface of the base plate portion 5. Adjust according to the height of. At this time, the adjustable height is equal to or less than the axial dimension of the female screw portion 11, and if the female screw portion 11 is a screw hole penetrating the metal plate 10, the male screw portion 12a of the support shaft 12 is made of metal. Be careful not to protrude from the upper surface of the plate 10.

Next, the mortar 9 is filled between the foundation 2 and the metal plate 10. The mortar 9 needs a certain strength to support the base plate portion 5 via the metal plate 10, but if it does not protrude upward from the upper surface of the metal plate 10, it may protrude above the lower surface of the metal plate 10. Well, especially high construction accuracy is not required.

After the mortar 9 is hardened, the through hole 51 of the base plate portion 5 joined to the lower end of the pillar portion 3 is passed through the anchor bolt 7 protruding from the foundation 2, the base plate portion 5 is placed on the upper surface of the metal plate 10, and the anchor bolt 7 is placed. And the nut 8, the base plate portion 5 and the pillar portion 3 are fixed to the foundation 2. After fixing the base plate portion 5 to the foundation 2, the lower end of the pillar portion 3 may be joined to the base plate portion 5.

After that, the frame body 14 is installed on the foundation 2 along the outer circumference of the base plate portion 5 so as to surround the entire circumference of the base plate portion 5, and the upper surface of the base plate portion 5 and the outer peripheral surface of the lower end portion of the pillar portion 3 are cut off. After covering with 15, concrete 4 is placed on the foundation 2 to form a slab. The concrete 4 covers the foundation 2, the base plate portion 5, and the anchor bolt 7 except for the gap 20 surrounded by the frame body 14 and the lower surface of the base plate portion 5.
The frame body 14 has flexibility so as to bend following the rotational deformation of the pillar portion 3 and the base plate portion 5, or is installed with a gap from the base plate portion 5 so as to allow the rotation of the base plate portion 5. Will be done.
The edge cutting material 15 has water impermeability and elasticity, absorbs rotational deformation of the pillar portion 3 and the base plate portion 5, and prevents water from entering the surfaces of the pillar portion 3 and the base plate portion 5.

As described above, according to the column base structure 1 of the present embodiment, the base 13 is installed on the foundation 2, and the metal plate 10 supported above the foundation 2 by the support shaft 12 is rotated to adjust the height. Since the mortar 9 is poured between the metal plate 10 having a determined height and the foundation 2, high construction accuracy is not required for the mortar 9, and the level of the piece material 6 can be easily adjusted.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIGS. 4 and 5. The description of the parts common to the first embodiment will be omitted. FIG. 4 is an exploded perspective view of the metal plate and the support shaft, and FIG. 5 is a bottom view of the metal plate and the support shaft.

In the second embodiment, the metal plate 10 is formed with three female screw portions 11 at equal intervals along a circle centered on the center of the metal plate 10. The female screw portion 11 is a threaded hole or a bottomed screw hole having an open lower end.
A male screw portion 12a formed at the upper end portion of the support shaft 12 is screwed into the female screw portion 11.

In order to install the piece material 6 on the foundation 2, first, the support shaft 12 is rotated to set the distance from the upper surface of the metal plate 10 to the lower ends of the three support shafts 12, and the upper surface of the foundation 2 is set. Adjust to the height from to the lower surface of the base plate portion 5. In this state, the lower end of the support shaft 12 is placed on the foundation 2, and the metal plate 10 is supported above the foundation 2 by the support shaft 12. Since three support shafts 12 are provided at equal intervals in the circumferential direction, the metal plate 10 is stably supported.
Next, the height of each part of the metal plate 10 is adjusted by rotating the support shaft 12 while checking the levelness of the upper surface of the metal plate 10 using a spirit level or the like.
Once the height of the metal plate 10 is determined, the mortar 9 is filled between the foundation 2 and the metal plate 10.

[Third Embodiment]
A third embodiment of the present invention will be described with reference to FIGS. 6 and 7. The description of the parts common to the first and second embodiments will be omitted. FIG. 6 is a vertical cross-sectional view of the column base structure, and FIG. 7 is a plan view of the anchor frame.

The anchor frame 16 is a member that is placed on a pedestal (not shown) installed on the ground to support the anchor bolts 7, and is embedded in the foundation 2.
The anchor frame 16 has a profile plate 17 that connects the upper ends of the anchor bolts 7. The profile plate 17 has a rectangular outer frame member 17a and a transfer member 17b arranged along a pair of diagonal lines connecting the corner portions of the outer frame member 17a. The anchor bolt 7 is attached by penetrating vertically through the central portion of each side of the outer frame member 17a.

A support shaft 12 is erected upward at the center of the profile plate 17 (intersection of the transfer material 17b). In the present embodiment, the support shaft 12 is composed of a bolt whose total length of the shaft portion is the male screw portion 12a. The support shaft 12 is fixed to the profile plate 17 by penetrating the profile plate 17 from bottom to top and sandwiching the profile plate 17 with a nut 12c screwed into a bolt head 12b and a male screw portion 12a.
When the foundation 2 is placed, the profile plate 17 of the anchor frame 16 is embedded in the foundation 2, but the upper end portion of the anchor bolt 7 and the upper end portion of the support shaft 12 project upward from the foundation 2.

In the central portion of the metal plate 10, a female screw portion 11 which is a through screw hole or a bottomed screw hole having an open lower end is formed.
To install the piece material 6 on the foundation 2, the female screw portion 11 of the metal plate 10 is screwed into the male screw portion 12a of the support shaft 12 protruding from the foundation 2, and the metal plate 10 is rotated to adjust the height. I do.
Next, the mortar 9 is filled between the metal plate 10 having a fixed height and the foundation 2.

[Other embodiments]
The present invention is not limited to the above embodiment. For example, the following are also included.

In the present embodiment, the pillar portion is a prism, but it may have another shape such as a cylinder, an H-shaped pillar, or the like.
Further, the shape of the base plate portion, the position of the through hole formed in the base plate portion, and the shape of the slit can be changed according to the shape and dimensions of the pillar portion.
Alternatively, the slit may be omitted to form a base plate portion having no easily deformable portion.

In the present embodiment, the frame body is arranged so as to surround the base plate portion, but instead of the frame body, an elastic member having water stopping property is arranged along the lower peripheral edge of the base plate portion to prevent rotational deformation of the base plate portion. It is also possible to form a gap under the base plate portion without obstruction.

In the present embodiment, the upper surface of the base plate portion, which is the base plate, and the lower end of the pillar portion, which is the pillar material, are joined, but the present invention is not limited to this. A projecting portion having the same cross-sectional shape as the pillar material may be provided on the upper surface of the base plate, and the lower end surface of the pillar material may be welded to the upper end surface of the projecting portion. In this case, the base plate corresponds to the base plate portion, and the projecting portion and the pillar material provided on the base plate correspond to the pillar portion.

In the present embodiment, the metal plate of the piece material is circular, but other shapes such as a square shape may be used.

In the first and third embodiments, the male threaded portion of the support shaft is screwed into the female threaded portion of the metal plate, but the support shaft having the male threaded portion is fixed to the lower surface of the metal plate and is upward from the foundation. It is also possible to erect a female threaded portion such as a henut and screw the male threaded portion to the female threaded portion.

In the present embodiment, the male screw portion of the support shaft is screwed into the screw hole formed in the metal plate, but a hole other than the female screw is formed in the metal plate, and the female screw portion (nut) is provided at the lower end of the hole. It may be rotatably attached and the female threaded portion may be screwed into the male threaded portion of the support shaft. By doing so, the height of the metal plate can be adjusted by rotating only the female screw portion without rotating the entire metal plate.

Each technical matter in any embodiment may be applied to other embodiments as examples.

1 Pillar base structure 2 Foundation 3 Pillar part 4 Concrete 5 Base plate part 6 Piece material 7 Anchor bolt 8 Nut 9 Mortal 10 Metal plate 11 Female thread part 12 Support shaft 12a Male thread part 12b Bolt head 12c Nut 13 Base 14 Frame body 15 Edge cutting material 16 Anchor frame 17 Shape plate 17a Outer frame material 17b Passing material 20 Gap 51 Through hole 52 Slit

Claims (5)

A pillar portion, a base plate portion provided at the lower end of the pillar portion and fixed to the foundation by anchor bolts, and a piece material installed on the foundation to support the base plate portion are provided, and the piece material is a mortar. And in a column base structure including a metal plate placed on the mortar.
The metal plate has a column base structure whose height can be adjusted via a support shaft that stands above the foundation. The column base structure according to claim 1, wherein the support shaft has a male screw portion, and the male screw portion is screwed into the female screw portion provided on the metal plate. The column base structure according to claim 2, wherein the support shaft is erected on a base installed on the base. Three female threaded portions are formed on the metal plate at equal intervals along a circle centered on the center of the metal plate, and the male threaded portions of the support shaft are screwed into each of these female threaded portions. The column base structure according to claim 2, which is characterized. The column base structure according to claim 1 or 2, wherein the support shaft is erected on an anchor frame to which the anchor bolts are attached and embedded in the foundation.

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