JP2000129778A - Column-beam joining part structure of steel frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance aseismatic strength of the reinforcement-made column- beam joining part by installing a beam on a column, arranging a floor slab on the beam, and arranging a small rigidity material around the column. SOLUTION: In the column-beam joining part of a steel frame structure, a column 1 and a beam 2 are joined so that a floor slab 4 is arranged on the beam 2. A low rigidity material 41 is arranged around the column 1 so that a large rigidity floor slab 4 integrally formed with a stud 42 is arranged on the outer periphery. When a large rigidity material is also arranged around the column 1, the stud 42 is not provided around the column 1. With this constitution, a synthetic beam effect around the column 1 is eliminated to restrain the occurrence of rupture of the beam 2. To start plasticization by a base material of the beam 2 except for the periphery of the column 1, a flange width of the beam 2 is narrowed so that horizontal directional stress intensity becomes larger than the welding part to clarify a plasticization position to enhance aseismatic strength. A plasticization starting position is provided in the base material of the beam 2 to restrain the occurrence of rupture of the beam 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam and column having a steel structure.

[0002]

2. Description of the Related Art The existing seismic design is based on the premise that, in a steel frame structure as shown in FIG. 5, for example, the joint between the column a and the beam b and the strength of the member connection exceed the strength of the member. For example, the column a and the beam b are joined by the diaphragm f and the upper flange d and the lower flange e of the beam, and are joined by the end of the web c and the side surface of the column. Further, the slab h and the beam b disposed on the beam b are fixed with the stud i, and the two are integrated by the composite beam effect.

[0003] However, during the Hyogoken-Nanbu Earthquake, joints between columns and beams were often damaged in steel structures. The feature is that most of the damage is the beam flange brittle fracture, the fracture mainly occurred on the lower flange, and the bottom of the scallop (notch) g, the weld metal, the heat affected zone, etc. were the fracture starting points. .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to increase the seismic strength of a reinforced column-beam joint.

[0005]

SUMMARY OF THE INVENTION The present invention is characterized in that in a building having a steel structure, a beam is attached to a column, a floor slab is arranged on the beam, and a material having low rigidity is arranged around the column. In a beam-column joint structure of steel structure or a building of steel structure, a beam is attached to a column, a floor slab is arranged on the beam, and a stud for fixing the beam and the floor slab is attached except for around the column. In a beam-to-column joint structure having a steel structure, or in a building having a steel structure, a beam is attached to a column, and a portion which is easily plasticized in a base material of the beam excluding the periphery of the column is smoothly formed. A beam-to-column joint structure having a steel structure, or a beam-to-column joint structure having a steel structure, wherein a portion which is easily plasticized has a narrow flange width of the beam. Or, steel beam-column joint structure Oite easily sites were plasticized is characterized by increasing the flange width of the beam around the pillar, in Column Joints structure steel structure.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

<A> Beam-to-column joint of steel structure In a beam-to-column joint of steel structure, a column 1 and a beam 2 are joined, and a floor slab 4 is arranged on the beam. For example, as shown in FIG. 1, a hollow steel pipe or H steel is used for the column 1, H steel or the like is used for the beam 2, and an upper flange 22 and a lower flange 23 of the beam are joined to the diaphragm 3. The web 21 is joined to the side surface of the column 1. The web 21 has scallops (notches 24)
Is provided to ensure joining such as welding.

<B> Floor Slab Structure A floor slab 4 is provided above the beam 2. For example, as shown in FIG. 1, a low-rigidity low-rigidity material 41 such as a styrofoam is arranged around the column, and a rigid slab such as a concrete slab is arranged around the periphery of the column. The concrete slab with large rigidity
Is formed integrally with the beam 2.

For example, as shown in FIG. 2, a rigid slab such as a concrete slab is also arranged around a column. However, no stud 42 is provided around the column, and the slab is not formed integrally with the beam 2. Does not cause beam effects. The beam 2 and the floor slab 4 are integrated by a stud 42 at a position away from the column.

[0010] The stud 42 is eliminated around the column within a distance L from the surface of the column 1, for example. This distance L is a position at which the elastic limit Mr is reached when the total plasticity moment Mu is reached at the plasticization forming position.

As described above, by disposing the low-rigid material 41 having low rigidity around the column or not disposing the stud, the horizontal stress of the concrete slab is not transmitted.

[0012] If a concrete slab including the periphery of a column is arranged and integrated with a beam by a stud, a combined beam effect of the beam and the slab is generated. As a result, at the time of design, the neutral axis moves to the slab side even though the centroid of the steel beam member is assumed to be the neutral axis, and the plasticization mechanism differs from the assumption at the time of design, and the It is considered that the beam flange brittle fracture occurs as described in the section.

<C> Beam Structure The beam 2 starts plasticizing with the base material of the beam 2 so that the scallop bottom, weld metal, heat-affected zone, etc., do not become fracture starting points. For this purpose, a position where the degree of stress in the horizontal direction becomes larger than that of the welded portion is set as a plasticization start position. For example, the beam 2 is configured as shown in FIGS.

In the case of FIG. 3, the flange shape of the beam is a dog bone shape, and a smooth concave portion is formed in the base material of the beam 2 away from the column 1. By making the change smooth, it is possible to avoid concentration of stress in a narrow range.

In the case of FIG. 4, the flange shape of the beam 2 is a horizontal haunch shape, and the flange width of the beam 2 is formed by smoothly changing so as to increase around the column.

[0016]

According to the present invention, the following effects can be obtained. <A> By clarifying the plasticized position at the beam end, seismic strength can be increased. <B> The composite beam effect around the column is eliminated, so that horizontal stress is not transmitted, and the occurrence of beam breakage can be suppressed. <C> By providing a plasticization start position in the base material of the beam, occurrence of breakage of the beam can be suppressed.

[Brief description of the drawings]

FIG. 1 is a structural view of a steel beam-column joint in which a low-rigidity material is arranged around a column.

FIG. 2 is a structural diagram of a steel beam-column joint without studs arranged around the column.

FIG. 3 is a structural view of a steel beam-column joint having a dog-bone shape.

FIG. 4 is a structural diagram of a steel beam-column joint having a horizontal haunched beam shape.

FIG. 5 is a structural view of a conventional steel beam-column joint.

Continued on the front page (72) Inventor Keiji Ogura F-25 terms in Taisei Construction Co., Ltd. 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo 3J048 AA02 BA05 BC01 DA06 EA38 3J066 AA26 BA04 BB04 BF02

Claims (5)

[Claims] Claims: 1. A steel beam-structured column structure, comprising: mounting a beam on a column; arranging a floor slab on the beam; and arranging a material having low rigidity around the column. . 2. A steel structure, wherein a beam is attached to a column, a floor slab is arranged on the beam, and a stud for fixing the beam and the floor slab is attached except for around the column. Beam-column joint structure. 3. A beam-column joint structure of a steel structure, wherein a beam is attached to a column, and a portion of the beam excluding the periphery of the column that is easily plasticized is formed smoothly. . 4. The beam-column joint structure of a steel structure according to claim 3, wherein the portion that is easily plasticized has a narrower flange width of the beam. 5. The beam-column joint of a steel structure according to claim 3, wherein the portion that is apt to be plasticized has a flange width of the beam enlarged around the column. Construction.