JPH1025805A - Steel column base anchoring structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a steel column base anchoring degree and install the steel column base easily by forming an anchor bolt of a deformed reinforcing bar, and providing the upper end part of the anchor bolt with an internal thread for mounting a positioning template. SOLUTION: The upper end part of an anchor bolt 17 is provided with an internal thread 22 for mounting a template 23. The template 23 is mounted on the upper end part of the anchor bolt 17 through a bolt 24 and the internal thread 22 to position the anchor bolt 17, and foundation concrete 9 is placed. The anchor bolt 17 formed of a deformed reinforcing bar (threaded bar) is embedded in the foundation concrete 9 to fix a column base hardware 11 jointed to a steel column. Adhesion to the foundation concrete 9 is thereby increased, and the template 23 can be fitted/removed only by attaching/detaching the small diameter bolt 24 and easily positioned. In addition, the outline dimensions of the template 23 are reduced to facilitate handling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing structure of a steel column base for fixing a steel column base constituting a building on foundation concrete.

[0002]

2. Description of the Related Art FIGS. 2 and 3 are a longitudinal sectional view and a plan view, respectively, showing a main part of a conventional steel column base anchoring structure. 2 and 3, reference numeral 5 denotes an anchor bolt, which is made of, for example, a steel bar, is provided with a screw at an upper end portion, and is positioned and embedded in the foundation concrete 9.

Next, after the foundation concrete 9 has been cured and solidified, the column base metal 11 is inserted through the central mortar 10.
Is placed on the lower end of the steel column 12, the steel column base 13 is placed and positioned, and then the non-shrink mortar 14 is filled between the column base metal 11 and the foundation concrete 9.

A washer 1 is provided at the upper end of the anchor bolt 5.
The steel column base 13 is fixed on the foundation concrete 9 by mounting the nut 5 and the nut 16 and tightening the nut 16.

[0005]

SUMMARY OF THE INVENTION A steel column base 1 having the above structure.
When a bending moment MH as shown in FIG. 2 acts on 3, a tensile force QF acts on one anchor bolt 5. What opposes the tensile force QF is the adhesive force between the anchor bolt 5 and the foundation concrete 9 and the fixing force of a fixing plate (not shown) fixed to the lower end of the anchor bolt 5. Of these, even if an attempt is made to increase the adhesive force between the anchor bolt 5 and the foundation concrete 9, the anchor bolt 5 is usually formed of round steel and has a smooth surface, so that the adhesive force is unstable and greatly increases. It is difficult to let.

Accordingly, there is a tendency that the embedding depth of the anchor bolt 5 is increased. However, the adhesion between the anchor bolt 5 and the foundation concrete 9 is broken down with time from the upper end portion and proceeds downward, so that the anchor bolt 5 advances downward. In this case, it is difficult to set the above-mentioned adhesive force, and as a result, there is a problem that the elongation of the anchor bolt 5 becomes large and the degree of fixation of the steel column base 13 decreases.

When the anchor bolt 5 is positioned at a predetermined position before the foundation concrete 9 is cast, a template is used for positioning in the horizontal direction. And a positioning hole through which the anchor bolt 5 can be inserted is provided.

Then, the anchor bolt 5 is inserted into the positioning hole of the template, and the template is clamped by the nut 16 from above and below.
Is fixed at a predetermined position, and the foundation concrete 9 is cast. After the foundation concrete 9 is cured and solidified, the template is removed and the steel column base 13 formed by joining the column base metal 11 is installed.

However, in the above-described conventional template mounting operation, first, the nut 16 is attached to the anchor bolt 5.
After screwing, the template is attached and nut 1
When the template is removed by screwing the screws 6, the removal of the nut 16, the removal of the template, and the removal of the nut 16 are required. That is, it is necessary to screw and remove two nuts 16 with respect to one anchor bolt 5, and especially in the case of a large-diameter anchor bolt 5, the nut 16 also becomes large. There is a problem that it is complicated.

Further, since the positioning holes to be provided in the template have a size corresponding to the diameter of the anchor bolts 5, the external dimensions of the template also become large corresponding to the column base hardware 11, so that the handling is complicated. There is also a problem.

The present invention solves the above-mentioned problems in the prior art, and provides a fixing structure for a steel column pedestal which can improve the degree of fixation of the steel column pedestal and can easily install the steel column pedestal. That is the task.

[0012]

In order to solve the above-mentioned problems, in the present invention, a steel column base formed by integrally joining a column base metal to the lower end of a steel column is embedded in a foundation concrete. In the anchoring structure of the steel column base fixed on the foundation concrete via the anchor bolt and the nut screwed to the upper end of the anchor bolt, the anchor bolt is formed of deformed steel bar, and the anchor bolt is formed on the upper end of the anchor bolt. The technical means of providing a female screw for mounting the positioning template was adopted.

In the present invention, as the deformed steel bars forming the anchor bolts, there can be used rebars called screw joints, bamboo joints, and cross joints. Of these, the use of a threaded bar is preferred because the nut can be screwed directly to the upper end.

Further, in the above invention, it is preferable that the shape of the projection of the anchor bolt on the vertical plane is U-shaped. By forming in this manner, the steel column base can be fixed by the adhesive force between the upright portion and the foundation concrete and the resistance of the bent portion of the foundation concrete. The mounting depth can be reduced, the degree of fixing of the steel column base and the design of the foundation rising portion are improved, and the installation of the anchoring portion is also simplified.

Further, in the above invention, it is preferable that the bottoms of the anchor bolts intersect in a projected state on a plane. By forming in this way, when a bending moment acts on the steel column base, a tensile force can be applied to only one upright portion of the U-shaped anchor bolt, and the other upright portion can have a tensile force. By applying a compressive force, the anchor bolt can be stabilized.

[0016]

FIG. 1 is an explanatory view showing the vicinity of the upper end of an anchor bolt according to an embodiment of the present invention.
(A) is a longitudinal sectional view of a main part, (b) is a plan view of a main part, and the same parts are denoted by the same reference numerals as in FIGS. 2 and 3.
In FIG. 1, reference numeral 21 denotes a bolt hole, which is provided at, for example, four corners of the column base hardware 11.

Next, reference numeral 17 denotes an anchor bolt formed of, for example, an SD490 deformed steel bar (threaded bar).
It is buried in the foundation concrete 9 and has a washer 1 at its upper end.
The nut 16 is screwed through the 5 and a steel column (not shown)
Then, the column base metal fitting 11 joined is fixed.

With the above configuration, a steel column base (not shown)
When the bending moment acts on the anchor bolt 17 and the tensile force QF acts on the anchor bolt 17,
Since 7 is formed by the threaded bar, it resists the tensile force QF by the adhesive force with the base concrete 9, so that the steel column base (see reference numeral 13 in FIG. 2) can be fixed. As a result, the embedding depth of the anchor bolt 17 can be made smaller than that of the conventional one shown in FIG.

Further, a bolt hole 2 provided in the column base hardware 11 is provided.
By grouting and filling grout 1, anchor bolt 17 and column base metal 11 can be integrated, horizontal load QH acting on column base metal 11 can be countered, and steel column base 13 (FIG. 2), the shear stress of the anchor bolt 17 can be sufficiently exerted.

Further, since the grout is injected and filled, the nut 16 can also be firmly fixed, so that the screwing of the double nut becomes unnecessary, and the installation work at the construction site becomes easy.

Next, in FIG. 1, 22 is a female screw,
It is provided at the upper end of the anchor bolt 17 and is for mounting the template 23. That is, before the foundation concrete 9 is cast, the template 23 is attached to the upper end of the anchor bolt 17 via the bolt 24 and the female screw 22.
In this state, the anchor bolt 17 is positioned at a predetermined position, and the foundation concrete 9 is cast.

With the above configuration, the mounting and dismounting of the template 23 can be performed only by attaching and detaching the small-diameter bolts 24, so that the positioning operation becomes extremely easy, and the bolt holes (not shown) to be formed in the template 23 are also reduced in diameter. Therefore, the external dimensions of the template 23 are reduced, and the handling is easy.

In the embodiment of the present invention described above, an example in which the anchor bolt 17 is formed by a threaded bar is described. Alternatively, a bamboo bar or a barbed bar may be used as the deformed steel bar. However, when these deformed steel bars are used, screw members are integrally joined to their ends by joining means such as, for example, friction welding, and are formed so that they can be screwed with a nut.

The present invention can be applied not only to a steel column made of a square steel pipe but also to a steel column made of a round steel pipe, a polygonal steel pipe, and an H-section steel. Naturally, geometric shapes other than shapes can be selected.

Further, the column base metal in the present invention is preferably formed by a casting means or a forging means, but may be formed by a thick steel plate.

[0026]

Since the present invention has the above-described configuration and operation, the following effects can be obtained.

(1) By forming the anchor bolts with the deformed steel bars, the adhesion to the foundation concrete is increased, the rotational rigidity is improved, and a higher-performance steel column base anchoring structure is obtained.

(2) The embedding depth can be greatly reduced and the proof stress can be improved as compared with the conventional method using a round steel anchor bolt. (3) Since the small-diameter female screw for mounting the positioning template is provided at the upper end of the anchor bolt, the size of the template can be reduced, and the attachment / detachment of the template becomes extremely easy.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the vicinity of an upper end portion of an anchor bolt according to an embodiment of the present invention, wherein (a) is a longitudinal sectional view of a main part, and (b) is a plan view of a main part.

FIG. 2 is a vertical sectional view of a main part showing an example of a conventional anchoring structure for a steel column base.

FIG. 3 is a partial cross-sectional essential part plan view showing a conventional anchoring structure for a steel column base.

[Description of Signs] 11 Column base hardware 12 Steel column 17 Anchor bolt 22 Female thread

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hidenobu Tanaka 2-4-2 Toyo, Koto-ku, Tokyo Inside Hitachi Koki Co., Ltd. (72) Kazuyuki Noguchi 2-4-2 Toyo, Koto-ku, Tokyo Hitachi Equipment Co., Ltd.

Claims (3)

[Claims] An anchor bolt embedded in a foundation concrete and a nut screwed to an upper end of the anchor bolt are provided with a steel column base formed by integrally joining a column base hardware to a lower end of the steel column. In the anchoring structure of the steel column base fixed on the foundation concrete through the anchor, the anchor bolt is formed of deformed steel bar, and the female screw for mounting the positioning template is provided at the upper end of the anchor bolt. Anchoring structure of steel column base. 2. The anchoring structure for a steel column base according to claim 1, wherein a projection shape of the anchor bolt onto a vertical plane is formed in a U-shape. 3. The anchoring structure for a steel column base according to claim 2, wherein the bottoms of the anchor bolts intersect in a projected state on a plane.