JP2003105859A - Embedded-in-concrete type column base structure using steel-pipe column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embedded-in-concrete type column base structure using a steel-pipe column, which can prevent local buckling of the steel-pipe column from being caused in a column base part and can enhance the strength of the steel-pipe column, in spite of the elimination of filling of the steel-pipe column with concrete in the column base part. SOLUTION: The thickness of a pipe wall of the steel-pipe column 1 is made greater in a region over both upper and lower sides in the position of the height of a top surface 2a of concrete 2 for embedment than in a pipe part above the region. The inside of the column 1 is formed as a concrete-unfilled hollow part of the concrete 2. A thickened pipe part 1a is formed in a state of being integral with the column 1, for example, by a thickening working method in which the pipe wall is heated and thickened by high frequency induction heating, etc., while a steel pipe is axially compressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete embedded column base structure using steel pipe columns.

[0002]

2. Description of the Related Art When a steel pipe column such as a circular steel pipe or a rectangular steel pipe is used as a column in a concrete-embedded column pedestal structure such as a neck wrapping, as shown in FIGS. A hole 53 is formed in the pipe wall so as to be located above the top surface 52a of the embedding concrete 52, and the concrete 5 is inserted into the steel pipe column 51 through the hole 53.
4 is driven in and filled, and the filled concrete 54 supports the steel pipe column 51 from the inside so as to prevent the local buckling of the steel pipe column 51 at the column base.

[0003]

However, the above-mentioned filled concrete 54 only prevents the occurrence of local buckling of the steel pipe column 51 at the column base, and the steel pipe column 5
It did not contribute to increasing the proof stress of No. 1.

Further, it takes time and effort to open a hole 53 for filling the pipe wall of the steel pipe column 51 with concrete 54,
Further, there is also a problem that the reinforcement 55 of the hole 53 is necessary and that the work for filling the concrete 54 is troublesome.

In view of the problems as described above, the present invention eliminates the filling of concrete into the steel pipe column at the column base, and yet prevents the local buckling of the steel pipe column at the column base. It is an object of the present invention to provide a concrete-embedded column base structure using a steel pipe column, which is capable of increasing the yield strength of the steel pipe column.

[0006]

[Means for Solving the Problems] The above-mentioned problem is solved in that the wall thickness of the pipe wall of the steel pipe column extends over at least the upper and lower sides of the top surface of the embedding concrete in the region above the pipe wall of the pipe portion. It is thicker than the wall thickness of the steel pipe, and the inside of the steel pipe is formed in the hollow part where concrete is not filled in the embedding concrete part, by the concrete embedded type column base structure using steel pipe columns Will be resolved.

In this structure, the wall thickness of the pipe wall of the steel pipe column is at least in the region extending above and below the top surface of the embedding concrete where local buckling is most likely to occur.
Since it is thicker than the wall thickness of the pipe portion above it, it is possible to effectively prevent the local buckling of the steel pipe column in the column base.

Moreover, by increasing the wall thickness of the pipe wall in the above region, the proof stress of the steel pipe column can be effectively increased.

Of course, since the region above this region is not thickened, it is possible to realize an economical proof structure without giving a large proof force unnecessarily.

Further, since the inside of the steel pipe is formed in the hollow portion in which the concrete for embedding is not filled with concrete, it is not necessary to fill the steel pipe of the column base with concrete, and therefore the steel pipe is also filled with concrete. There is no need to drill or reinforce the holes, and these troublesome processes for filling the concrete can be eliminated, and the occurrence of the local buckling as described above occurs. You can prevent it with less effort.

In the case where the thickened pipe portion is formed integrally with a steel pipe column, such processing is performed by heating the pipe wall by high frequency induction heating while compressing the steel pipe in the axial direction to increase the thickness. This can be easily performed by a thickening method and the like, and a steel pipe pillar material provided with such a thickened pipe portion can be easily manufactured.

When the thickened pipe portion extends to the lower end of the steel pipe column, the local buckling of the steel pipe column at the column base can be more reliably prevented. Such a thickened tube portion can be easily formed by a thickening method in which the tube wall is thickened by the compression and heating as described above.

The thickened pipe portion is formed integrally with a steel pipe column, and the outer peripheral surface of the thickened pipe portion projects outward from the outer peripheral face of the steel pipe column by this integral molding. And, in the steel pipe column, in the embedding concrete below the top surface height position of the embedding concrete,
One or two or more outwardly projecting thickening pipe portions formed by the same integral molding may be provided at intervals in the vertical direction with the thickening pipe portion.

In this structure, the outer overhanging thickened pipe portion, which is completely embedded below the top surface of the embedding concrete, plays the role of a shear connector, and firmly embeds the embedding concrete and the steel pipe column. It is possible to increase the degree of fixation of the steel pipe column to the embedding concrete.

Moreover, this outwardly bulging thickened pipe portion which functions as a shear connector is formed by the same integral molding as the upper thickened pipe portion which prevents the occurrence of local buckling. This outwardly bulging thickened pipe part plays a role of preventing local buckling by compressing the steel pipe in the axial direction and heating the pipe wall at high intervals such as high frequency induction heating. Can be easily formed together with the thickened pipe portion of (1), and a steel pipe column member having such an outwardly thickened thickened pipe portion can be easily manufactured.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

In the column base structure of the first embodiment shown in FIGS. 1 and 2, 1 is a steel pipe column, which is a square steel pipe,
The column base portion of the rectangular steel tube column 1 is embedded in the embedding concrete 2 made of root-wound reinforced concrete. 3 is a base plate attached to the lower end of the steel pipe column, and 4 is an anchor bolt.

In this column base structure, the rectangular steel pipe column 1 is
The wall thickness of the pipe wall is the top surface 2a of the embedding concrete 2.
In the region 1a extending to the upper and lower sides of the height position, the thickness of the pipe wall of the pipe portion 1b above it is increased, and in the present embodiment, the thickened pipe portion 1a is a square steel pipe column. It is extended to the lower end of 1. That is, in the present embodiment, the rectangular steel pipe column 1 is formed by the thickened pipe portion 1a from a position above the height position of the top surface 2a of the embedding concrete 2 to the lower end embedded in the embedding concrete 2. The thickness of the pipe portion 1b above the thickened pipe portion 1a is increased.

In the present embodiment, the thickened pipe portion 1a is formed integrally with the rectangular steel pipe column 1, and the tubular wall is compressed by the high frequency induction heating while compressing the rectangular steel pipe in the axial direction. It is formed by heating and increasing the thickness.

In this column base, the inside 5 of the rectangular steel pipe column 1 is left hollow without being filled with concrete, so that concrete can be driven into the steel pipe 1 of the column base and filled. No holes are provided and no reinforcement of such holes is made.

In the above column base structure, the top surface 2a of the embedding concrete 2 in which the steel pipe column 1 is most likely to cause local buckling.
Since the wall thickness of the pipe wall of the steel pipe portion 1a in the region extending above and below the height position of is higher than the pipe wall thickness of the steel pipe portion 1b above that, the thickening pipe portion 1a It is possible to effectively prevent the local buckling of the steel pipe column 1 in the column base portion, and to increase the yield strength of the steel pipe column 1.

Moreover, in this embodiment, the thickened pipe portion 1
Since a extends to the lower end of the steel pipe column 1, it is possible to more reliably prevent local buckling of the steel pipe column 1 at the column base portion, and it is possible to increase the yield strength. On the other hand,
Since the pipe portion 1b above the thickened pipe portion 1a is not thickened, the pipe portion 1b does not needlessly have a large yield strength, and an economical yield structure can be realized.

In the column base, the inside 5 of the steel pipe column 1 is left hollow without being filled with concrete, and the local buckling of the steel pipe column 1 in the column base is caused by the thickened pipe portion 1a. Since it is configured to prevent, the steel pipe of the column base 1
It is not necessary to fill the hollow part 5 of the concrete with concrete, and therefore, it is not necessary to form a hole for concrete filling in the steel pipe 1 or to reinforce the hole. Troublesome processing can be eliminated.

Further, the thickened pipe portion 1a is formed integrally with the rectangular steel pipe column 1, and such integral molding is such that the pipe wall is thickened by heating and axial compression. Since it can be easily performed by the processing method, the steel pipe column 1 having such a thickened pipe portion 1a can be easily manufactured.

In the column base structure of the second embodiment shown in FIG. 3 (a), the square steel pipe column 1 has a wall thickness of both sides above and below the height position of the top surface 2a of the embedding concrete 2. Only in the region 1a extending over the pipe wall 1b, the wall thickness of the pipe wall 1b above the pipe wall 1b is increased, and the pipe portion 1c from the thickened pipe portion 1a to the lower end of the rectangular steel pipe column 1 is increased. Like the pipe portion 1b above the thick pipe portion 1a, the pipe portion is formed by a pipe portion whose wall thickness is not increased.

Similarly to the thickened pipe portion 1a of the above-mentioned embodiment, the thickened pipe portion 1a of the present embodiment is also formed integrally with the rectangular steel pipe column 1, and the rectangular steel pipe is compressed in the axial direction. However, it is formed by heating the tube wall by high-frequency induction heating or the like to increase the thickness.

In the column base structure of the present embodiment, the steel pipe column 1 is the region where the steel pipe column 1 extends over both upper and lower sides of the top surface 2a of the embedding concrete 2 where the local buckling is most likely to occur.
Since only a is thickened, the steel pipe column in the column base 1
The occurrence of local buckling can be effectively prevented by increasing the thickness.

In the column base structure of the third embodiment shown in FIG. 3B, the wall thickness of the square steel pipe column 1 extends above and below the height position of the top surface 2a of the embedding concrete 2. In the region 1a, the wall thickness of the pipe portion 1b above it is thicker than that of the pipe wall, and the square steel pipe column 1 has a lower wall than the height position of the top surface 2a of the embedding concrete 2. In the embedding concrete 2, the plurality of thickening pipe portions 1d are vertically spaced from the thickening pipe portion 1a.
... is provided. These thickened pipe portions 1a, 1d, ... Are also integrally formed on the rectangular steel tube column 1 like the thickened pipe portion 1a of the above-described embodiment, and the rectangular steel pipes are compressed while being compressed in the axial direction. It is formed by heating the wall by high-frequency induction heating or the like to increase the thickness, and by this thickening process, any of the thickened pipe portions 1a, 1d ... Is stretched outward from the outer peripheral surface of the rectangular steel pipe column 1. It is thickened so that it will come out.

In this column base structure, the outwardly bulging thickened pipe portions 1d, which will be present in a completely embedded state below the top surface 2a of the embedding concrete 2, play the role of a shear connector, Concrete 2 and steel tube column 1
And are firmly integrated, and the degree of fixation of the steel pipe column 1 to the embedding concrete 2 can be made high.

Further, this outwardly bulging thickened pipe portion 1d, which plays the role of a shear connector, is formed in the same manner, that is, a steel pipe is used as an axial line, after forming the thickened pipe portion 1a for preventing local buckling at the upper side. It can be easily formed by heating the pipe wall by high-frequency induction heating, etc. at predetermined intervals while compressing in the direction. Therefore, the conventional troublesome parts such as the stud connector can be formed. It is possible to eliminate mounting, and it is possible to easily manufacture a steel pipe column material having a shear connector function and a local buckling prevention function.

In the fourth embodiment shown in FIG. 4 (a), the embedding concrete 2 is made of non-standing reinforced concrete. As described above, the embedding concrete may be one in which the column base portion of the steel pipe column 1 is embedded. In addition, although the square steel tubular column 1 of the first embodiment is used, it may be the type of the second embodiment or the type of the third embodiment.

The fifth embodiment shown in FIG. 4B is a case where the steel pipe column 1 is made of a circular steel pipe. Type is first
Although it is of the embodiment, it goes without saying that it may be of the type of the second embodiment or of the type of the third embodiment.

[0033]

EFFECTS OF THE INVENTION Since the present invention is as described above, it is possible to eliminate the filling of concrete into the steel pipe column at the column base, and yet prevent the local buckling of the steel pipe column at the column base. It is also possible to increase the yield strength of the steel pipe column.

[Brief description of drawings]

1A and 1B show a column base structure of a first embodiment, FIG. 1A is a sectional side view, and FIG. 1B is a sectional view taken along line I-I of FIG. 1A.

FIG. 2 is a sectional perspective view of the same.

FIG. 3A is a side view showing a column base structure of the second embodiment, and FIG. 3B is a side view showing a column base structure of the third embodiment.

FIG. 4 (a) is a sectional side view showing a column base structure of a fourth embodiment, and FIG. 4 (b) is a sectional perspective view of a column base portion of a steel pipe column showing a fifth embodiment.

5A and 5B show a conventional column base structure, in which FIG. 5A is a sectional side view, and FIG. 5B is a sectional view taken along line II-II in FIG.

[Explanation of symbols]

1 ... Steel tube column 1a ... Thickened pipe section 1d ... Thickened tube section overhanging outward 2… Embedding concrete 2a ... top surface 5 ... Hollow part

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Claims (4)

[Claims] 1. The wall thickness of the steel pipe column is made thicker than the wall thickness of the pipe wall above the pipe wall in a region extending at least both above and below the ceiling surface height position of the embedding concrete. The inside of the steel pipe is formed in the hollow portion where the concrete for embedding is not filled with concrete, and the concrete embedded column base structure using the steel pipe column. 2. The concrete-embedded column base structure using a steel pipe column according to claim 1, wherein the thickened pipe portion is formed integrally with the steel pipe column. 3. A concrete-embedded column base structure using a steel pipe column according to claim 1, wherein the thickened pipe portion extends to a lower end of the steel pipe column. 4. The thickened pipe portion is formed integrally with a steel pipe column, and the outer peripheral surface of the thickened pipe portion projects outward from the outer peripheral face of the steel pipe column by this integral molding. ,
In addition, the steel pipe column is formed by one or two or more same integral moldings in the embedding concrete below the top surface height position of the embedding concrete with the thickening pipe portion vertically spaced apart. The concrete-embedded column base structure using a steel pipe column according to claim 1, further comprising an outwardly thickened pipe portion.