JP2763308B2 - Steel reinforced concrete column base - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a column base of a steel reinforced concrete building.

[Conventional technology]

A steel reinforced concrete column base is composed of a steel column and a plurality of reinforcing bars arranged outside the steel column. FIG. 5 is a partially omitted longitudinal sectional view showing an example of a conventional steel frame reinforced concrete column base. In FIG. 5, the column base 40 includes a steel column 41, a plurality of reinforcing bars 42, concrete 43, a base plate 44, a plurality of anchor bolts 45, and a foundation concrete 46. That is, the base plate 44 is integrally joined to the lower end of the steel column 41 by welding, a plurality of anchor bolts 45 are connected to the base plate 44, and the anchor bolts 45 are embedded in the foundation concrete 46. In this case, the base plate 44 is generally formed of a steel plate, but the rigidity and proof strength cannot be sufficiently secured. That is, if a material having a large thickness is used for the purpose of increasing rigidity and proof strength, a defect is easily generated in a welded joint with the steel column 41. This is because, in a steel sheet with a large thickness, there is much laminar segregation (lamination) of P, S, etc. during rolling, so when this is welded and joined, it is present near the joint due to heating during welding. This is because the laminar segregated portion is continuously broken. On the other hand, even if the means for reinforcing by providing a rib or the like is employed, it is difficult to secure rigidity because the vicinity of the connection portion with the anchor bolt 45 is locally deformed. Therefore, in the conventional column base 40, the strength of the steel frame portion including the base plate 44 is not sufficient, and only the reinforced concrete portion constituted by the reinforcing bar 42 and the concrete 43 can exert sufficient strength. For this reason, a reinforcing reinforcing bar 47 is provided to compensate for the insufficient strength of the steel frame portion, or the diameter and / or the number of the reinforcing bars 42 is increased, and further, the cross-sectional dimension of the entire column base 40 is increased. There is a need to. Therefore, the effective use space of the building is reduced, and the rebar arrangement is not only complicated, but also the concrete arrangement is complicated.
There is a problem that the filling property of the resin is deteriorated.

[Problems to be solved by the invention]

In order to solve the above-mentioned problems, for example, a structure as shown in FIG. 6 is implemented. In FIG. 6, the column base 50 comprises a steel column 51, a plurality of reinforcing bars 52, concrete 53, a base plate 54, a plurality of anchor bolts 55, and a foundation concrete 56 in the same manner as shown in FIG. It is characterized in that the steel columns 51 are continuously buried in the foundation concrete 56. Therefore, the pedestal 50 is the head 50a
Both the bottom 50b and the bottom 50b have the performance equivalent to the sum of the performance of the steel frame portion and the reinforced concrete portion.
Therefore, problems such as an increase in the cross-sectional dimension of the column base 50 and an increase in the diameter and / or the number of the reinforcing bars 52 as shown in FIG. 5 are temporarily solved.

However, as apparent from FIG. 6, since the steel column 51 is embedded in the foundation concrete 56, the anchor bolt
55 the foundation concrete 56 other foundation concrete deeper
There is a problem that the foundation work cost increases because it needs to be buried inside. In addition, it is necessary to perform the work of placing the concrete foundations 56 and 57, respectively, and because it interferes with the steel columns 51 and the reinforcing bars 58 in the foundation concrete 56, the work of arranging the reinforcements becomes complicated and the construction period becomes longer. Coexist.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a steel reinforced concrete column base capable of ensuring sufficient strength of a steel frame portion, easily arranging a reinforcing bar, and shortening a construction period. Aim.

[Means for solving the problem]

In order to achieve the above object, in the first invention,
A steel reinforced concrete structure constructed by integrally joining a column base metal to the lower end of a steel column, connecting a plurality of anchor bolts to the column base metal, and arranging a plurality of rebars outside the steel column. In the column base, the column base metal is made of cast steel or forged steel in a flat plate shape, and a flat portion including the outer contour of the lower end face of the steel column is provided, and the outer contour of the column base metal is notched to avoid interference with a reinforcing bar. The technical means of providing and constructing a part was adopted.

Next, in the second invention, a column base metal is integrally joined to the lower end of the steel column, and a plurality of anchor bolts are connected to the column base metal, and a plurality of reinforcing bars are provided outside the steel column. In a steel-framed reinforced concrete column base which is arranged and formed, a column base metal is formed by an integral protruding portion and a bottom plate portion from cast steel or forged steel, and an upper end portion of the protruding portion is planar and a lower end surface of a steel column. The bottom plate part is formed in a flat plate shape and has a cutout that avoids interference with the reinforcing bar, and the bottom plate part is formed at the boundary between the protrusion and the bottom plate part. The base of the concave curved surface is formed, and the relationship between the height h and the thickness t of the protruding portion, the maximum outer dimension L and the maximum thickness d of the bottom plate portion is 0.08 ≦ h / L ≦ 0.25,1.0 ≦ h
The technical means that /d≦3.0 and 0.2 ≦ t / h ≦ 0.8 was adopted.

In the above invention, it is preferable to install the column base metal above the foundation beam because the operation of placing the foundation concrete becomes easy.

Further, it is preferable that the anchor bolt is formed of a high-tensile material having a tensile strength of 50 kg / mm ² or more.

[Action]

With the above configuration, it is possible to prevent interference between the column base hardware and the rebar, and to expect an effect of ensuring complete filling of concrete.

〔Example〕

FIG. 1 is a partially omitted longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line AA in FIG. In both figures, the column base 10 is composed of a steel column 11, a plurality of reinforcing bars 12, concrete 13, column base hardware 14, a plurality of anchor bolts 15, and foundation concrete 16. The steel column 11 has, for example, an H-shaped steel 11a and another H-shaped steel 11b formed by cutting the central portion welded to each other at a web portion, and has a substantially cross-sectional shape. The pillar base metal 14 is formed of cast steel or forged steel and has a substantially cross-sectional plane shape as described later, and is integrally joined to the lower end of the steel column 11 by welding. In this case, a groove (not shown) for welding is provided at the lower end of the steel column 11. Next, a fixing plate 15a is sandwiched between the lower ends of the anchor bolts 15 to be embedded in the foundation concrete 16 and connected to the column base metal fitting 14. The bottom of the column base metal fitting 14 is made of basic concrete.
It is provided at the same position as the upper end surface of the 16 or above through a mortar (not shown).

Next, FIG. 3 is an enlarged perspective view showing an example of a column base hardware in the embodiment of the present invention. In FIG. 3, the column base metal member 14 is formed of cast steel or forged steel as described above, and its central portion corresponds to the outer contour of the lower end portion of the steel column 11 shown in FIG. 1 and FIG. A flat portion 14a including the outer contour is provided, and four notches 14b are provided in the outer contour to form a substantially cross-shaped overall planar shape. Reference numeral 14c denotes a bolt hole through which the anchor bolt 15 shown in FIG. 1 can be inserted.

With the above configuration, the thickness of the column base metal 14 can be sufficiently ensured, and the welded joint with the steel column 11 does not have any cracking defect that occurs in the conventional steel plate. Stiffness and strength can be sufficiently ensured. In addition, the notch 14b is provided in the outer contour of the column base metal 14, so that interference with the reinforcing bar 12 to be disposed outside the steel column 11 can be completely prevented, and the gap with the reinforcing bar 12 can be reduced to a predetermined value. Value can be secured and bar arrangement work can be facilitated. Further, the filling of the concrete 13 to be provided around the steel column 11 and the reinforcing bar 12 can be completed.

FIG. 4 (a) is a perspective view showing another example of the column base hardware in the embodiment of the present invention. In FIG. 4 (a), the column base metal 24 is formed of cast steel or forged steel in the same manner as shown in FIG. The central flat portion 24a is provided with a projection 24d having an outer contour that matches the outer contour of the lower end face of the steel column (not shown) to be joined, and a groove 24e is provided at the end of the projecting portion 24d. Provide. Next, reference numeral 24f denotes a bottom plate portion which forms the entire outer contour and has four cutout portions 24b as in the case of FIG. Reference numeral 24g denotes a base, which is formed in a concave curved shape at the boundary between the projection 24d and the bottom plate 24f. 24c is a bolt hole.

According to the above configuration, the lower end portion of the steel column (not shown) is integrated by welding in the same manner as that shown in FIG. 3, but as shown in FIG. Since the groove 24e is provided, the groove of the steel column to be joined can be omitted. Further, since the protruding portion 24d is provided integrally with the flat portion 24a of the column base metal 24, the rigidity of the entire column base metal 24 can be increased, and the bending due to the welding joint with the steel column can be prevented. Note that the protruding portion 24d and the flat portion 24a
And / or a concave base 2 at the boundary with the bottom plate 24f.
Since 4 g is provided, local stress concentration can be prevented or reduced. Other operations are the same as those shown in FIG.

Next, FIG. 4 (b) is a sectional view taken along the line BB in FIG. 4 (a), and the same parts are denoted by the same reference numerals as in FIG. 4 (a). In FIG. 4 (b), d is the thickness of the bottom plate 24f, d '
Is the thickness of the flat portion 24a, h and t are the height and thickness of the protruding portion 24d, respectively, and L is the outer dimension of the bottom plate portion 24f. Bottom plate 2
Since 4f is provided with a seat for a nut or a washer which is usually screwed to an anchor bolt (not shown), d> d ', so the thickness d of the bottom plate 24f is considered. When the long side and the short side are present in the bottom plate portion 24f, L represents the maximum outer dimension.

In FIG. 4 (b), when h / L <0.08, the amount of curvature of the bottom plate 24f sharply increases due to the welding connection with the steel column,
It is not preferable because sufficient surface contact with the foundation concrete cannot be obtained. On the other hand, if h / L> 0.25, the weight of the entire column base hardware 24 increases, which is larger than the required steel material of the conventional base plate, which is uneconomical. Therefore, it is preferable that 0.08 ≦ h / L ≦ 0.25, and more preferably, 0.10 ≦ h / L ≦ 0.18. Next, h / d should be considered in the same manner as described above.
That is, if h / d <1.0, the reinforcing effect of the protruding portion 24d is small, and the amount of bending of the bottom plate portion 24f is undesirably large. On the other hand, if h / d> 3.0, the weight of the entire column base hardware 24 increases, which is uneconomical as described above. Therefore 1.0 ≦ h / d ≦
It is preferably 3.0, and more preferably 1.2 ≦ h / d ≦ 2.2. Further, if t / h <0.2, the amount of curvature of the bottom plate portion 24f is small, but the weight of the entire column base metal fitting 24 is large, and the thickness t is too small, so that a sufficient weld joint cannot be obtained. . Further, excessive residual strain is generated in the protruding portion 24d, resulting in insufficient strength.
On the other hand, if t / h> 0.8, the amount of curvature of the bottom plate 24f increases sharply, and sufficient surface contact with the foundation concrete cannot be obtained.
Alternatively, the thickness t becomes excessively large, and an unnecessarily large groove is provided, making the welding operation difficult. Therefore 0.
It is preferable that 2 ≦ t / h ≦ 0.8.

In the present embodiment, the cross section of the steel column is described as having a substantially cross shape. However, the present invention is not limited to this, and even if the cross section is square, polygonal, circular, H-shaped, or the like, the operation is not limited to this. The same is true. Further, although the planer projection outer contour of the column base metal fitting is shown as being square, it may be polygonal, circular, or any other shape. Further, it is needless to say that the shape and the number of the cutouts can be appropriately selected. Therefore, the shape of the pillar base metal can be selected from, for example, a substantially T-shape for the stud and a substantially L-shape for the corner pillar, in addition to the substantially cross shape for the middle pillar in this embodiment.

〔The invention's effect〕

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

(1) Since the rigidity of the column base metal is high, the rigidity and strength of the steel frame portion constituting the column base can be sufficiently ensured.

(2) Therefore, it is not necessary to increase the cross section of the column base, and the effective use space of the building can be increased.

(3) It is not necessary to increase the diameter and / or the number of installation of the reinforcing bars, and the work of arranging the reinforcing bars is easy.

(4) Since there is no need to bury the steel columns in the foundation concrete, it is possible to prevent an increase in foundation construction costs, and since the steel columns do not interfere with the reinforcing bars in the foundation beams, the foundation work is easy. .

(5) Since the interference between the column base hardware and the reinforcing bar can be prevented, the bars can be arranged in an optimum state, and the strength and reliability of the column base can be improved.

[Brief description of the drawings]

FIG. 1 is a partially omitted longitudinal sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged cross-sectional view taken along the line AA in FIG. 1, FIGS. 3 and 4 (a) are enlarged perspective views showing column base hardware in the embodiment of the present invention, and FIG. 4 (b) is FIG. B- in a)
B and FIG. 5 and FIG. 6 are each a partially omitted vertical sectional view showing an example of a conventional steel frame reinforced concrete column base. 11: steel column, 12: reinforcing bar, 13: concrete, 14, 24: column base hardware, 1
4a, 24a: flat portion, 14b, 24b: cutout portion, 24d: protruding portion, 24f: bottom plate portion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidenari Matsuo 1-9-1, Kitahama-ku, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Hitachi Metals Co., Ltd. Wakamatsu Plant (72) Inventor Norio Ito 1 Kitahama, Wakamatsu-ku, Kitakyushu-shi, Fukuoka No. 9-1, Hitachi Metals Co., Ltd., Wakamatsu Factory (72) Inventor Isamu Yamamoto 1-9-1, Kitahama-ku, Wakamatsu-ku, Kitakyushu-shi, Fukuoka Prefecture, Japan Inside Wakamatsu Factory, Hitachi Metals Co., Ltd. (72) Inventor Kuniaki Sato Minato-ku, Tokyo Kashima Construction Co., Ltd. 1-2-7 Moto Akasaka (72) Inventor Yoshihiro Nakamura Kashima Construction Co., Ltd. 1-2-7 Moto Akasaka, Minato-ku, Tokyo (72) Inventor Akio Tomita Moto-Akasaka, Minato-ku, Tokyo 1-2-7 Kashima Construction Co., Ltd. (72) Inventor Shunichi Yamada 1-2-7 Motoakasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (72) Inventor Previous Shozo 1-2-7 Moto-Akasaka, Minato-ku, Tokyo Kashima Construction Co., Ltd. (56) References JP-A-63-51541 (JP, A) Japanese Utility Model Application No. 48-49423 (Japanese Utility Model Application No. 49-150830) Microfilm (JP, U) of the contents of the specification and drawings attached to the application

Claims (4)

(57) [Claims] 1. A column base metal is integrally joined to a lower end portion of a steel column, a plurality of anchor bolts are connected to the column base metal, and a plurality of reinforcing bars are disposed outside the steel column. In the constructed steel reinforced concrete column base, the base metal is formed of cast steel or forged steel in a flat plate shape, and a flat portion including the outer shape of the lower end portion of the steel column is provided. A steel frame reinforced concrete column base characterized by being provided with a notch for avoiding interference. 2. A column base metal is integrally joined to a lower end of a steel column, a plurality of anchor bolts are connected to the column base metal, and a plurality of rebars are arranged outside the steel column. In the formed steel reinforced concrete column base, the column base metal is formed by a cast part or a forged steel part with an integral protruding part and a bottom plate part, and the upper end part of the protruding part is planar and the outer contour of the lower end part end face of the steel frame column. Formed into a conforming outer contour, and the bottom plate is formed in a flat plate shape and has a notch in the outer contour to avoid interference with rebar, and a concave curved surface is formed at the boundary between the protrusion and the bottom plate. The base is formed, and the height h and the thickness t of the protrusion, the maximum outer dimension L and the maximum thickness d of the bottom plate are formed.
The relationship of 0.08 ≦ h / L ≦ 0.25, 1.0 ≦ h / d ≦ 3.0, 0.2 ≦ t / h ≦ 0.
A steel-framed reinforced concrete column base characterized by a rating of 8. 3. The steel reinforced concrete column base according to claim 1, wherein the column base metal is installed above the foundation beam. 4. The steel reinforced concrete column base according to claim 1, wherein the anchor bolt is formed of a high-tensile material having a tensile strength of 50 kg / mm ² or more.