JP2007154536A - Column and beam frame using steel pipe column filled with concrete - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a column and beam frame capable of suppressing the occurrence of any cracking or partial destruction near joints of the beam when a horizontal force due to an earthquake or the like acts to the frame by emphansizing a yield strength due to bending of portions and parts near the beam connections in a steel pipe column filled with concrete. <P>SOLUTION: A hollow-shaped precast concrete piece 4 made with high strength concrete is installed at each beam connection or part near the beam connection in the steel pipe column 2 filled with concrete thereby enhancing its flexural capacity of the beam connection position A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of column beam structures using concrete-filled steel pipes as columns, and more specifically, by increasing the bending strength of a portion or part near a beam joint in a concrete-filled steel pipe column, The present invention relates to a column beam structure that suppresses the occurrence of cracks, partial fractures, and the like in the vicinity of beam joints when horizontal force is applied.

Conventionally, steel pipe columns in which concrete is filled in the column beam frame have been adopted due to the advantage of having excellent seismic performance and rigidity. Concrete-filled steel pipe columns and beams are usually welded together using a diaphragm. However, the welded joint between the concrete-filled steel pipe column and the beam is a so-called dangerous cross-sectional position where the horizontal force such as earthquake acts most strongly, and the concrete-filled steel pipe column affected by the welding heat is near the beam joint. Problems such as cracking and partial destruction occur.
As a well-known technique of a column beam structure using a concrete-filled steel pipe column, for example, in Patent Document 1 below, a partition is provided at a necessary place in the steel pipe column, and an important part to which a large structural force is applied such as a joint part of the beam A technique is disclosed in which only concrete is filled in and the other portions are left hollow.

  Patent Document 2 discloses a concrete-filled steel pipe column formed by connecting a plurality of concrete-filled steel pipes by welding joint, and filling high-fluidity concrete into the central axis part and weld joint part in the steel pipe. In addition, a column beam structure using a concrete-filled steel pipe column with improved solidity is disclosed. However, the column beam frame disclosed in Patent Document 2 is configured to suppress cracks, partial breakage, and the like in the vicinity of a beam joint of a concrete-filled steel pipe column when a horizontal force such as an earthquake acts. is not.

JP-A-5-51999 JP-A-5-59787

  The column beam frame using the concrete-filled steel pipe column of Patent Document 1 is not a configuration in which the bending strength at the critical cross-section position, which is a welded joint between the column and the beam, is emphasized, but is inherently provided by the concrete-filled steel pipe column. This is a configuration in which the performance is increased only at a necessary portion, and it aims at an economically inexpensive structure by saving the use of concrete, which is different from the technical idea of the present invention.

  The purpose of the present invention is to increase the bending proof strength of the portion or part near the beam joint in the concrete-filled steel pipe column that is welded to the beam, so that the vicinity of the beam joint affected by the welding heat is The purpose of the present invention is to provide a column beam structure using concrete-filled steel pipe columns that can prevent damage such as cracks and partial fractures due to the action of horizontal force.

As means for solving the above-mentioned problems of the prior art, a column beam frame using a concrete-filled steel pipe column according to the invention described in claim 1 is:
A hollow precast concrete piece 4 made of high-strength concrete is installed in a portion or a part near the beam joint portion A in the concrete-filled steel pipe column 2 and the bending strength in the vicinity of the beam joint portion A is enhanced. It is characterized by.

The invention described in claim 2 is a column beam frame using the concrete-filled steel pipe column described in claim 1,
A taper portion 5 that increases the fluidity of the filled concrete is formed at the concrete inlet portion or outlet portion of the hollow portion of the hollow precast concrete piece 4.

The invention described in claim 3 is a column beam frame using the concrete-filled steel pipe column described in claim 1 or 2,
An air vent hole 6 penetrating in the vertical direction is formed in a cylindrical wall portion around the hollow portion of the hollow precast concrete piece 4.

Invention of Claim 4 is the column beam frame using the concrete filling steel pipe pillar described in any one of Claims 1-3,
The hollow precast concrete piece 4 is characterized in that it is formed to have a length comparable to the outer diameter of the precast concrete piece 4.

A column beam frame using a concrete-filled steel pipe column according to the invention of claim 5 is:
A reinforcing steel material 9 such as a reinforcing bar or a steel pipe is installed at a portion or a portion in the vicinity of the beam joint portion A in the concrete-filled steel pipe column 2, and the bending strength in the vicinity of the beam joint portion A is enhanced. To do.

  According to the column beam frame 1 using the concrete-filled steel pipe column 2 of the present invention, a hollow precast concrete piece 4 made of high-strength concrete is provided in a portion or part near the beam joint A in the concrete-filled steel tube column 2. 4 or the reinforcing steel material 9 such as a reinforcing bar or steel pipe is installed and reinforced so that the bending strength in the vicinity of the beam joint A of the concrete-filled steel pipe column 2 is increased and the beam joint affected by the welding heat is applied. It is possible to suppress the vicinity A of the portion from being damaged by a horizontal force such as an earthquake such as a crack or partial destruction.

  Hollow-shaped precast concrete pieces 4 and 4 made of high-strength concrete are installed in a portion or part near the beam joint portion A of the concrete-filled steel pipe column 2 to increase the bending strength in the vicinity of the beam joint portion A. .

  Below, the column beam frame 1 using the concrete filling steel pipe pillar 2 which concerns on this invention is demonstrated based on the illustrated example.

FIG. 1 shows a cylindrical precast made of high-strength concrete, having the same diameter as that of the concrete-filled steel pipe 20 at a portion or part in the vicinity of the beam joint A in the concrete-filled steel pipe column 2 having a circular cross-sectional shape. The embodiment of the column beam frame 1 in which the concrete piece 4 was installed is shown. Incidentally, reference numeral 8 in FIG. 1 denotes a diaphragm for transmitting the stress of the beam, and the beam 3 is welded to the concrete-filled steel pipe column 2 via the diaphragm 8. The high-strength concrete refers to a concrete having a compressive strength of about 27 to 36 N / mm ² or more than that. In addition, the precast concrete piece 4 in the illustrated example has a cylindrical shape matched to the concrete-filled steel pipe column 2 having a circular cross-sectional shape. However, when the cross-sectional shape of the concrete-filled steel pipe column 2 is a square shape, A square tubular precast concrete piece is installed in accordance with the cross-sectional shape of the filled steel pipe.

  FIG. 2A shows a perspective view of the precast concrete piece 4. FIG. 2B shows a plan view of the precast concrete piece 4. The precast concrete piece 4 is manufactured by casting or centrifugal molding. A tapered portion 5 is formed at the concrete inlet portion or outlet portion of the hollow portion of the precast concrete piece 4 to enhance the fluidity of the concrete 21 filled into the steel pipe 20 (the invention according to claim 2). In order to obtain the same effect, the air vent holes 6 (four in the illustrated embodiment) penetrating in the vertical direction through the cylindrical wall portion around the hollow portion coincide with the air vent holes formed in the diaphragm 8. (Invention of claim 3). However, if the air vent hole 6 is provided, it is not always necessary to form the tapered portion 5 in the hollow portion of the precast concrete piece 4. In addition, although illustration was abbreviate | omitted, reinforcement steel materials, such as a reinforcing bar or a steel pipe, are installed in the inside of the said precast concrete piece 4, and it can also implement as a structure which raised bending strength.

  The precast concrete piece 4 is formed to have a length comparable to the outer diameter of the precast concrete piece 4. This is a dimension in consideration of the bending moment distribution existing in the axial direction of the concrete-filled steel pipe column 2, and is designed to have an appropriate length in consideration of strength (invention of claim 4).

Next, a construction procedure for installing the precast concrete piece 4 having the above-described configuration in a portion or a part in the vicinity of the beam joint portion A of the concrete-filled steel pipe column 2 will be described with reference to FIGS.
The precast concrete piece 4 is usually inserted into a steel pipe 20 for filling in advance at a steel frame manufacturing factory. The construction procedure is as follows. First, two precast concrete pieces 4 and 4 arranged in tandem are inserted into the steel pipe 20 from the upper opening of the steel pipe 20 welded to the beam 3 via the diaphragm 8 at the lower end (FIG. 3). (See (A)). The outer diameter of the precast concrete piece 4 is approximately the same as the inner diameter of the steel pipe 20, but the dimensions are set in consideration of fitting tolerance so that the steel pipe 2 can be smoothly inserted. Then, a fixed pin 7 such as a parallel pin or a taper 1/50 pin is inserted and driven into a common hole formed in the precast concrete piece 4 and the steel pipe 20 (see FIG. 1), and the lower precast concrete is inserted into the steel pipe 20. The piece 4 is fixed. However, the fixing pin 7 is not limited to the means for fixing the precast concrete piece 4 into the steel pipe 20 and may be fixed using, for example, an adhesive. Next, the diaphragm 8 is attached to the upper end of the steel pipe 20, and the beam 3 is welded to the diaphragm 8 (see FIG. 3B), and then the upper precast concrete piece 4 is connected to the vicinity of the beam joint of the steel pipe 20. The precast piece 4 is lifted up to a part A or a part, and the precast piece 4 is fixed to the steel pipe 20 with a fixing pin 7 (see FIG. 3C). Finally, the concrete 21 is filled into the steel pipe 20 through the hollow portion of the precast concrete piece 4 to complete the concrete-filled steel pipe column 2.

  However, when the precast concrete piece 4 is at the upper part of the welding position of the diaphragm 8, as shown in FIGS. 4 (A) and 4 (B), the normal steel frame construction method is over and before the next section steel construction method begins. The precast concrete piece 4 is inserted into the steel pipe 20 (see FIG. 4A), and the precast concrete piece 4 is fixed in the steel pipe 20 in the manner described above with reference to FIG. 3 (FIG. 4 ( (See B)).

  Therefore, according to the column beam frame 1 using the concrete-filled steel pipe column 2 according to the present invention, the precast concrete piece 4 reinforces the portion or part of the concrete-filled steel tube column 2 in the vicinity of the beam joint portion A to increase the bending strength. Since the height is increased, the beam joint vicinity A affected by the welding heat can suppress damage such as cracks and partial fractures due to a horizontal force such as an earthquake.

  In general, the concrete-filled steel pipe column 2 having a shear span ratio exceeding 3 is handled as a middle column whose member rank is limited to FA regardless of the buckling length ratio, and costs are increased. However, in the beam-column joint structure 1 according to the present invention, the buckling length can be reduced by the precast concrete piece 4 provided on the concrete-filled steel pipe column 2, so that what is conventionally designed as a middle column is a short column It is also possible to design, the member rank can be FB or FC, and the cost can be reduced.

  5 (A) and 5 (B) show that the reinforcing steel material 9 is installed and reinforced in the vicinity or part of the beam joint in the concrete-filled steel pipe column 2 so as to reinforce the beam of the concrete-filled steel pipe column 2. The Example of the column beam frame 1 which raised the bending yield strength of the mouth vicinity A is shown. That is, in the column beam frame 1 of this embodiment, the beam joint vicinity A affected by the welding heat is similar to the effect described in the first embodiment (described in paragraphs [0020] and [0021]). It is possible to prevent damage such as cracks and partial destruction due to the action of horizontal forces such as earthquakes. The reinforcing steel material 9 is not limited to a reinforcing bar, and for example, a steel pipe or the like may be used, and the same effects as described above can be achieved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. The present invention can be implemented in various forms without departing from the gist of the present invention.

1 is an elevational sectional view showing a column beam frame of Example 1. FIG. (A) is a perspective view of a precast concrete piece, (B) is a top view of a precast concrete piece. (A)-(C) are explanatory drawings which showed the construction procedure which installs a precast concrete piece in a steel pipe. (A), (B) is explanatory drawing which showed the different construction procedure which installs a precast concrete piece in a steel pipe. (A) is the expanded vertical sectional view which showed the column beam frame of Example 2, (B) is the II sectional view taken on the line of (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Column beam frame 2 Concrete filling steel pipe column 3 Beam 4 Precast concrete piece 5 Tapered part 6 Air vent hole 9 Reinforced steel material A Near beam joint part

Claims (5)

  A hollow precast concrete piece made of high-strength concrete is installed in a portion or part near a beam joint in a concrete-filled steel pipe column, and the bending strength near the beam joint is enhanced. Column beam frame using concrete filled steel pipe columns.   2. The concrete-filled steel pipe column according to claim 1, wherein a taper portion that enhances fluidity of the filled concrete is formed at a concrete inlet portion or outlet portion of a hollow portion of the hollow precast concrete piece. The column beam frame used.   The concrete-filled steel pipe column according to claim 1 or 2, wherein an air vent hole penetrating in a vertical direction is formed in a cylindrical wall portion around the hollow portion of the hollow precast concrete piece. Column beam frame.   The hollow-filled precast concrete piece is formed to have a length approximately equal to the outer diameter of the precast concrete piece, and the concrete-filled steel pipe column according to any one of claims 1 to 3 is used. There was a column beam frame.   Reinforced steel such as reinforcing bars or steel pipes are installed in the vicinity or part of the beam joint in the concrete-filled steel pipe column, and the bending strength in the vicinity of the beam joint is enhanced. Column beam structure using steel pipe columns.

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