JP2002146922A - Anchorage structure of exposed column base - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems for an anchorage structure of the conventional exposed column base so that a concrete foundation is thinned to lighten excavation work and concrete casting work and, at the same time, to efficiently carry out work by unitizing anchor metal fittings. SOLUTION: For the anchorage structure of the exposed column base connecting the column base section of a steel framed column to the concrete foundation with an anchor bolt, the anchor bolt is made to pass through up to the lower part of the concrete foundation, at the same time, the lower end thereof is connected to the anchor fittings arranged to the lower surface of the concrete foundation, and the head of the anchor bolt is inserted into a base plate of the column base section mounted on the upper surface of the concrete foundation to connect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a steel column base to a concrete foundation in a steel frame or a steel reinforced concrete building. For steel columns, exposed column bases that settle on the concrete foundation with their column bases exposed, embedded column bases that embed steel columns in concrete,
In addition, there is a base-winding column base that is fixed to a concrete foundation by rolling concrete around a steel frame column. The present invention relates to a fixing structure of an exposed column base.

[0002]

2. Description of the Related Art In general, an anchoring structure of an exposed column base to a concrete foundation in a steel frame or a steel-framed reinforced concrete building is fixed on a discarded concrete S via a steel frame 1 as shown in FIG. The metal fitting 3 is placed, and the fixing metal 3 and the base plate 52 placed on the concrete foundation 4 are tightly connected by the anchor bolt 2 and the nut 21. Reinforcing bars 41 are arranged vertically and horizontally on the concrete foundation 4, and column bases 51 of the steel columns are fixed to a base plate 52. Further, a mortar M is filled between the concrete foundation 4 and the base plate 52 as required.

[0003] The construction of such a fixing structure is performed in the following procedure. First, the ground is cut to a predetermined level to perform crushed stone work, or abandoned concrete S is cast, and the steel frame 1 is placed at a predetermined position on the upper surface thereof. Next, the fixing hardware 3 is mounted on the steel frame 1 and the fixing hardware 3 is attached.
Attach anchor bolt 2 to 3 by screwing or welding. Then, after arranging the reinforcing bar 41 in the space which becomes the concrete foundation 4 above the waste concrete S,
The concrete form is cast and concrete C is cast. After the curing period, enter the construction method of the steel column 5, place a leveling tool such as a mortar block or a steel plate liner on the upper surface of the concrete foundation 4, put the base plate 52 of the column base 51, and anchor bolts in the bolt holes of the base plate 52. Insert the head of 2 and nut 21
After leveling, tighten the nut 21 to secure the column base 51
To the concrete foundation 4. The mortar M is filled in the gap between the base concrete 4 and the lower part of the base plate 52 and grouted.

[0004]

In such a structure for anchoring to a concrete foundation, the thickness of the concrete foundation 4 is first determined by the tensile force transmitted from the anchor bolts 2 to the anchoring hardware 3 as a trigger. Is defined as having a resistance to the destruction of the cone that is pulled out from the periphery of the cone in a cone shape, thereby determining the thickness from the fixing hardware 3 to the upper surface of the concrete foundation 4. Further, it is necessary to secure a legal cover thickness for the fixing metal 3 buried in the concrete foundation 4, which determines the thickness from the fixing metal 3 to the lower surface of the concrete foundation 4.
In other words, since the minimum thickness is required considering the strength against cone breakage above the anchorage hardware 3 and the concrete cover thickness is required below the minimum, the excavation depth of the foundation is necessarily large. Absent.

[0005] In the construction of the anchoring structure on site, when the concrete C is cast, the steel frame 1 is easily distorted or misaligned due to the pressure of the concrete, so that the position of the anchor bolt 2 changes. Modifications may need to be made when building the steel column 5. Further, depending on the shape of the fixing hardware 3, there is also a problem that the concrete does not sufficiently flow below the fixing hardware 3, leaving voids and water remaining therein, causing corrosion of the fixing hardware 3. In addition, arranging the steel frame 1 and the fixing hardware 3 and attaching the anchor bolts 2 to the fixing hardware 3 also require a great deal of manpower.

SUMMARY OF THE INVENTION The present invention solves such a problem in the conventional anchoring structure for exposed column bases, reduces the work of excavation and concrete placing by thinning the concrete foundation, and unitizes the anchoring hardware for construction. The purpose is to improve the efficiency.

[0007]

According to the present invention, there is provided an anchoring structure for an exposed column base in which a column base of a steel column is joined to a concrete foundation by an anchor bolt, wherein the anchor bolt penetrates to a lower portion of the concrete foundation, The lower end thereof is joined to a fixing hardware arranged on the lower surface of the concrete foundation, and the head of the anchor bolt is inserted and joined to a base plate of a column base placed on the upper surface of the concrete foundation. It is.

[0008] In the above invention, it is preferable that at least the exposed surface of the fixing metal is rust-proofing or that the fixing metal is buried with the upper surface exposed in half precast concrete. Preferably, a screw hole for the anchor bolt is provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on examples. FIG. 1 is a sectional view showing an embodiment of a fixing structure for an exposed column base according to the present invention, and FIG. 2 is a plan view thereof.

As shown in FIG. 1, in the present invention, the anchor bolt 2 is penetrated to the lower part of the concrete foundation 4, and the fixing hardware 3 is not embedded in the concrete foundation 4, but is arranged on the lower surface. In this case, the thickness of the concrete C may be a thickness in consideration of only the proof strength against cone destruction by the fixing hardware 3.

In the example shown in FIG. 1, the fixing hardware 3 is buried in a half precast concrete 32 as shown in FIG. 3 with only its upper surface exposed. Therefore, the side and lower surfaces of the fixing hardware are completely covered with the half precast concrete 32, thereby ensuring the rust prevention of the fixing hardware. Therefore, the function of the legal covering of the concrete with respect to the fixing hardware 3 is secured by the half precast concrete 32, so that it is not necessary to consider in this case. The fixing hardware 3 embedded in the half precast concrete is provided with a screw hole for the anchor bolt 2.

In constructing the exposed column base shown in FIG.
First, the ground is cut down to a predetermined level, and then the crushed stone is carried out. At this time, the fixing hardware 3 embedded in the half precast concrete shown in FIG. 3 is embedded in the crushed stone ground S so that the upper surface thereof is flush with the crushed stone ground. After a while
The anchor bolt 2 is screwed into the anchor bolt screw hole of the fixing hardware 3 and fixed. Subsequently, the reinforcement of the concrete foundation 4 is provided by the reinforcing bars 41 and the formwork is constructed. At this time, the legal cover thickness of the concrete C is ensured on the lower surface side of the reinforcing bar 41. After that, concrete C is poured into the formwork.

After the concrete 4 is cast, a concrete foundation is completed after a predetermined curing period, and thereafter, a method of building a steel column is performed. In the construction process, the column base 51 is tied to the concrete foundation 4 without changing from the conventional one.
If necessary, mortar M is filled and grouted.

In this example, the fixing hardware 3 is arranged on the lower surface of the concrete foundation 4. Therefore, the thickness of the anchoring metal upper surface side of the concrete foundation 4 has a strength against cone destruction in which the concrete is pulled out from the periphery of the anchoring hardware 3 in a conical shape due to the tensile tension transmitted from the anchor bolt 2 to the anchoring hardware 3. It may be designed as On the other hand, the legal cover of the concrete on the lower surface side of the fixing hardware 3 does not need to be considered especially since its function is secured by the precast concrete 32. Therefore, the thickness of the concrete foundation 4 can be reduced by that much.

Further, the anchoring hardware 3 is fixed to the half precast concrete and is embedded in the crushed stone ground S with good stability, and the anchor bolt 2 is fixed to the anchoring hardware 3 with good stability by screwing. In addition, there is an advantage that the anchoring hardware can be mounted very accurately at a predetermined position without displacing the fixing hardware when the concrete C is poured.

FIG. 4 is a sectional view showing another embodiment of the fixing structure of the exposed column base of the present invention. Also in this example, the fixing hardware 3 is placed on the lower surface side of the concrete foundation 4 as embedded in half precast concrete. However, the anchor metal 3 is placed on the crushed stone ground S while being embedded in half precast concrete. Therefore, the concrete foundation 4 is placed so as to wrap the half precast concrete together with the fixing hardware 3. In this case, when the part 411 of the reinforcing bar 41 is arranged directly on the fixing metal 3, the legal cover thickness of the concrete with respect to the reinforcing bar 411 is secured as the thickness of the half precast concrete.

In this case, the thickness of the concrete foundation 4 is
On the upper surface side of the fixing hardware 3, the concrete has a strength against cone destruction in which the concrete is pulled out from the periphery of the fixing hardware 3, and on the lower surface side, the thickness is equal to the thickness of the half precast concrete. Also in this case, the anchoring hardware 3 is stably installed on the crushed stone ground S as one with half precast concrete, and the anchor bolt 2 is fixed to the anchoring hardware 3 with good stability by screwing. Therefore, there is an advantage that the anchoring hardware can be mounted very accurately at a predetermined position without displacing the fixing hardware at the time of placing the concrete C.

Although the present invention has been described based on two embodiments, the embodiments of the present invention are not limited to these embodiments, and may take various forms. For example, fixing hardware 3
It does not have to be integrated with the half precast concrete as shown in FIG. 3, but may be a single thick steel plate whose exposed surface is rust-proofed. The rust preventive means is not particularly limited, and any known anticorrosive means can be used. For example, zinc plating is sufficient.

The fixing of the anchor bolts to the fixing hardware 3 is not limited to the screw-in type shown in FIGS. 1 and 4, but may be a method of fixing to the fixing hardware by welding or the like. Further, the crushed stone ground business on which the fixing hardware is placed can be replaced with discarded concrete.
It should be noted that a template or the like can be attached to the heads of the plurality of anchor bolts and positioned relative to each other. Thereby, the displacement of the anchor bolt 2 can be more completely prevented.

[0020]

According to the present invention, the thickness of the concrete foundation is reduced, so that the work of excavation and concrete casting is reduced, the steel frame is eliminated, and the flatness of the fixing hardware is improved, and the construction is performed. It has an excellent effect that the efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a fixing structure of an exposed column base according to an embodiment of the present invention.

FIG. 2 is a plan view showing a fixing structure of an exposed column base according to the embodiment of the present invention.

FIG. 3 is a partially cutaway perspective view of the structure of a fixing hardware embedded in half precast concrete.

FIG. 4 is a sectional view showing another embodiment of the fixing structure of the exposed column base according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a fixing structure of a conventional exposed column base.

[Explanation of symbols]

 1: steel frame 2: anchor bolt 3: anchor metal 4: concrete foundation 5: steel column 21: nut 32: half precast concrete 41: steel bar 51: column base 52: base plate C: concrete M: mortar S: discarded concrete or Crushed stone industry

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirokazu Yasuda 2-3-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo Kawasaki Steel Corporation Tokyo Head Office (72) Inventor Isamu Miyauchi Kitahonmachidori, Chuo-ku, Kobe City, Hyogo Prefecture 1-1-28 Kawatetsu Building Materials Co., Ltd. (72) Inventor Koji Yoda 1-1-1-2 Kita-Honmachidori, Chuo-ku, Kobe-shi, Hyogo Kawatetsu Building Materials Co., Ltd. F-term (reference) 2E125 AA03 AA45 AB01 AC04 AC15 AG03 AG12 AG41 AG60 BA07 BA22 BB02 BB08 BB22 BB24 BB30 BD01 BF04 CA04 CA13 CA19 CA82 EA33

Claims (4)

[Claims] 1. An anchoring structure for an exposed column base in which a column base of a steel column is joined to a concrete foundation by an anchor bolt, wherein the anchor bolt penetrates to a lower part of the concrete foundation, and a lower end of the lower part is a lower surface of the concrete foundation. The exposed column base, wherein the head of the anchor bolt is inserted into and joined to the base plate of the column base placed on the upper surface of the concrete foundation. Fixing structure. 2. The fixing structure according to claim 1, wherein the fixing hardware is buried in half precast concrete with its upper surface exposed. 3. The fixing structure for an exposed column base according to claim 1, wherein at least the exposed surface of the fixing hardware has been subjected to a rust prevention treatment. 4. The fixing structure for an exposed column base according to claim 1, wherein said fixing hardware is provided with a screw hole for an anchor bolt.