JP6347593B2 - Steel frame - Google Patents

Description

  The present invention relates to a steel frame of a steel structure building.

In a steel structure building, there is a case where a bracket method is used in which a beam bracket made of an H-shaped steel material or the like is joined to a side surface of a column and the beam steel frame is horizontally mounted using the beam bracket.
This beam bracket is required to follow the deformation of the column during an earthquake.

  Patent Document 1 discloses a beam-column joint structure in which a haunch plate made of a triangular low yield point steel plate is attached to both the left and right sides of a flange of a beam bracket. This column beam connection structure improves the deformation tracking performance of the beam bracket with respect to the column in the event of an earthquake or the like and absorbs the hysteresis energy at the time of the earthquake by the haunch plate.

  On the other hand, since the cross-sectional shape of the beam bracket changes abruptly at the end of the haunch plate (the corner formed by the haunch plate and the flange of the beam bracket), plastic strain tends to concentrate.

Also, in the beam bracket provided with a haunch plate, the cross-sectional area of the beam bracket is increased by the haunch plate, so the position where the stress due to the bending moment is maximized starts from the end of the beam bracket (joint to the column). Move to the end of the plate (the corner between the haunch plate and the flange).
As described above, in the beam bracket with the haunch plate, the stress (plastic strain, bending moment) concentrates on the corner of the flange of the beam bracket and the haunch plate, and there is a possibility that the damage proceeds intensively.

  In Patent Document 2, the flange or web of the beam bracket is reinforced so as to straddle the point where the cross-sectional shape of the beam bracket suddenly changes (the cross-section sudden change position) in order to avoid such stress concentration at the corner. A column beam joining structure for joining members is disclosed. According to such a beam-column joint structure, the position where the stress due to the bending moment is maximized can be moved by installing the reinforcing member, so that the location where the plastic strain is concentrated and the position where the bending moment is maximized can be separated. .

JP 2000-273971 A JP2013-181292A

In the column beam connection structure of Patent Document 2, it is necessary to fix the reinforcing member to the beam bracket separately from the hunch plate.
In addition, although the location where the plastic strain is concentrated and the position where the bending moment is maximized are separated, the corner where the cross-sectional shape changes remains, so there is a concern about the influence of the plastic strain in this portion.

  From such a viewpoint, an object of the present invention is to provide a steel frame that has a simple configuration and is less likely to cause stress concentration.

An example of the steel frame is composed of a pair of beam brackets joined to a pair of columns, and a beam steel frame joined at both ends to the pair of beam brackets, and the beam bracket and the beam steel frame are splice plates. And the beam bracket includes a main material having a web and a flange, and a widening material that widens the flange, and the widening material has a total length of the main material. There are those made of a low yield point steel material joined to the side surface of the flange .

According to such a steel frame, since the corner portion is not formed by the flange of the beam bracket and the widening material, stress concentration is unlikely to occur in the beam bracket.
Moreover, since it is a simple structure which only widens the flange of a beam bracket, the effort at the time of manufacture can also be reduced.

In order to solve the above problems, a steel frame according to a first aspect of the present invention includes a pair of beam brackets joined to a pair of columns, and a beam steel frame joined at both ends to the pair of beam brackets. the bracket and the beam steel are friction bonded via a plurality of splice plates and a plurality of high-strength bolts, the beam bracket includes a main member having a web and flanges, and a widening member for widening the flange The length from the column to the high-strength bolt of the flange located on the most column side from the column is more than the beam, and the splice plate of the flange is crimped with the flange sandwiched from above and below the widening member is made from a low yield point steel joined to a side surface of the flange, than high strength bolt of the flange located on the most pillar side from said pillar Extends to Kihari steel side has a length according to the splicing plates of the flange, and is characterized in that the length of the wider material is less than the length of said main member.
Moreover, the steel frame of the second invention is characterized in that the end of the widening member has a length located near the high-strength bolt of the plurality of flanges from the column.

According to such a steel frame, although the corner portion is formed by the flange and the widened portion of the beam bracket, the splice plate is frictionally joined via the high-strength bolt, so that stress concentration hardly occurs in the beam bracket.
Moreover, since it is a simple structure which only widens the flange of a beam bracket, the effort at the time of manufacture can also be reduced.

  According to the present invention, it is possible to construct a steel frame that has a simple configuration and is less likely to cause stress concentration.

It is a perspective view which shows the steel frame structure which concerns on embodiment of this invention. It is a figure which shows the edge part of the steel frame of 1st embodiment, Comprising: (a) is a plane sectional view, (b) is a front view. It is an expansion perspective view which shows a part of steel frame structure of FIG. It is a figure which shows the edge part of the steel frame of 2nd embodiment, Comprising: (a) is a plane sectional view, (b) is a front view.

<First embodiment>
In the first embodiment, as shown in FIG. 1, a steel frame 1 horizontally mounted between a pair of columns P and P will be described.
The steel frame 1 includes a pair of beam brackets 3 and 3 respectively joined to a pair of columns P and P, and a beam steel frame 5 having both ends joined to the pair of beam brackets 3 and 3. That is, the steel frame 1 is assembled by a so-called bracket method.

  The beam bracket 3 is fixed to the through diaphragm 4 and the column member 2 constituting a part of the column P.

As shown in FIG. 2, the column member 2 is formed of a square steel pipe having a predetermined thickness, and constitutes a part of the column P.
A beam bracket 3 is fixed to the outer surface of the column member 2.

  In addition, the column member 2 does not necessarily need to be a square steel pipe, and the cross-sectional shape of the column member 2 is not limited. Moreover, the column member 2 does not necessarily need to be comprised with the steel pipe, for example, you may comprise with H-section steel.

The beam bracket 3 constitutes the end of the steel frame 1 and is fixed to the side surface of the column member 2.
The beam bracket 3 includes a main material 30 and hunches (widening materials) 31 and 32.

The main material 30 of the present embodiment is composed of a normal steel material having a pair of upper and lower flanges 30a, 30b and a web 30c. The flanges 30a and 30b have the same width over the entire length of the main material.
In the present embodiment, H-shaped steel is used as the main material 30, but the main material 30 is not necessarily H-shaped steel, and may be, for example, L-shaped steel or groove-shaped steel.

The beam steel frame 5 is made of an H-shaped steel having the same cross section as the main material 30.
As shown in FIG. 2, the beam steel frame 5 and the main material 30 are joined via splice plates 6, 6,... ing.

  The splice plates 6 that join the flanges are disposed above and below the flanges. In the present embodiment, one splice plate 6 is disposed on the upper surface of the upper flange, and one splice plate 6 is disposed on each side of the web on the lower surface of the upper flange. Similarly, on the lower flange, one splice plate 6 is disposed on the lower surface, and one splice plate 6 is disposed on each side of the web on the upper surface.

  As shown in FIG. 3, the splice plates 6 and 6 sandwiching the flange from above and below are pressure-bonded to the flange by a plurality of high-strength bolts 7, 7,. In the present embodiment, the splice plates 6 and 6 are pressure-bonded to each flange with 12 high-strength bolts 7, 7,.

  As shown in FIG. 2 (b), the splice plates 6, 6 disposed across the webs sandwich the web of the beam steel frame 5 and the main material 30 from the left and right, and a plurality of high strength bolts 7 are provided. , 7,... In the present embodiment, the splice plate is pressure-bonded to the web with ten high-strength bolts 7, 7,... Each, but the number of high-strength bolts 7 is not limited.

  The web 30 c of the main material 30 is welded to the column member 2, and the upper and lower flanges 30 a and 30 b are welded to the through diaphragms 4 and 4. The diaphragm 4 may be joined only through the upper flange 30a.

  The beam bracket 3 is widened by attaching haunches 31 and 32 to the left and right of the flanges 30a and 30b, respectively.

  The haunches 31 and 32 are steel plates formed of a low yield point steel material. In the present embodiment, the plate thickness of the haunches 31 and 32 is equal to the plate thickness of the flanges 30a and 30b, but the plate thickness of the haunches 31 and 32 may be different from the plate thickness of the flanges 30a and 30b.

  The haunches 31 and 32 are welded in a state where the side end surfaces are abutted against the flanges 30 a and 30 b, and the base end surfaces are welded to the end surfaces of the diaphragm 4.

  A haunch (hereinafter referred to as “upper haunch”) 31 attached to the upper flange 30a has the same length as the main material 30 as shown in FIG.

Further, the upper stage haunch 31 has the same width over the entire length and is formed in a rectangular shape in plan view.
Note that the width of the upper stage haunch 31 does not necessarily have to be the same over the entire length, and may be gradually reduced at the end on the beam steel frame 5 side, or may be cut off on an arc.

A haunch (hereinafter referred to as “lower hunch”) 32 attached to the lower flange 30b has the same length as the main material 30 as shown in FIG. 1 and FIG. Moreover, the lower stage haunch 32 has the same width | variety over the full length, and is formed in planar view rectangle.
In addition, the lower stage haunch 32 may be cut off at the end on the beam steel frame 5 side.

  The through diaphragm 4 is a steel plate disposed so as to divide the column P vertically as shown in FIG. That is, the through diaphragm 4 is sandwiched between the square steel pipes constituting the column P (column member 2) from above and below.

  As shown in FIG. 2A, the through diaphragm 4 is configured by a plate material having an area larger than the outer shape of the column member 2, and an end portion of the through diaphragm 4 projects from the outer surface of the column member 2. ing.

  In the present embodiment, as shown in FIG. 2B, the two diaphragms 4 are arranged at intervals in two upper and lower stages. The upper diaphragm 41 is disposed at the same height position as the upper flange 30a of the beam bracket 3, and the lower diaphragm 42 is disposed at the same height position as the lower flange 30b of the beam bracket 3. .

  The upper and lower flanges 30 a and 30 b and the upper and lower hunches 31 and 32 of the main material 30 are welded to the projecting portion of the through diaphragm 4.

  In the present embodiment, the case where the upper and lower through diaphragms 41 and 42 are disposed at the same height as the upper and lower flanges 30a and 30b has been described, but the height position of the through diaphragm 4 is not necessarily the upper and lower flanges. It is not necessary to coincide with 30a and 30b.

As described above, in the steel frame 1 of the present embodiment, the haunch 31 has the same length as the main material 30 of the beam bracket 3, and the end surface of the haunch 31 extends on the extension of the boundary between the main material 30 and the beam steel frame 5. Since it is positioned, no corner portion is formed in the beam bracket 3.
Therefore, it can prevent that the location where stress concentrates on the beam bracket 3 is formed. Therefore, it is possible to prevent crack damage and the like from occurring in the flange of the main material 30.

  Since the beam bracket 3 has a simple configuration in which the haunch 31 is fixed to the flange of the main material, the beam bracket 3 can be manufactured easily and inexpensively.

  Since the beam bracket 3 and the beam steel frame 5 are joined by a high-strength bolt and a splice plate, the force at the joint is transmitted via the splice plate. Therefore, the stress concentration at the end of the haunch 31 is alleviated.

Further, even in the case of a large-scale earthquake, the hunches 31 and 32 made of the low yield point steel material absorb the shaking in a building having a substantially elastic range, so that the shaking at the time of the earthquake can be stopped early.
Therefore, by adopting the steel frame 1 of the present embodiment, it is possible to construct a building having excellent earthquake resistance.

<Second Embodiment>
As shown in FIG. 4, the steel frame 1 according to the second embodiment is a steel frame according to the first embodiment in that the lengths of the haunches (widening materials) 31 and 32 are shorter than the main material 30. 1 and different.
The details of the column member 2, the main material 30, the through diaphragm 4, the beam steel frame 5, the splice plate 6 and the high strength bolt 7 of the second embodiment are the same as those shown in the first embodiment. Detailed description is omitted.

The haunches 31 and 32 of the present embodiment are made of a low yield point steel material.
The haunches 31 and 32 are fixed in a state where the side end surfaces are abutted against the upper flange 30 a of the main material 30, and the base end surfaces are welded to the end surfaces of the diaphragm 4.

  The haunches 31 and 32 have such lengths that their tips are located in the vicinity of the second high-strength bolt 6 from the column P. The lengths of the haunches 31 and 32 are not limited to this, and the tip position may be on the beam steel frame 5 side of the first high-strength bolt 7 from the column P.

  The haunches 31 and 32 of the present embodiment gradually decrease in width at the end on the beam steel frame 5 side as they approach the beam steel frame 5, but are formed to have the same width except at the end. In addition, the shape of the front-end | tip part of the haunches 31 and 32 is not limited, It does not necessarily need to be gradually reduced. For example, you may have the same width over the full length.

  As described above, in the steel frame 1 of the present embodiment, the haunches 31 and 32 have a length applied to the splice plate 6, so that the corners are formed by the haunches 31 and 32 and the flange, but the cross-sectional shape is The stress acting by the change is distributed through the splice plate 6. Therefore, stress concentration at the ends of the haunches 31 and 32 hardly occurs, and crack damage or the like can be prevented from occurring in the flange of the main material 30.

  Since the operational effects of the steel frame 1 according to the other second embodiment are the same as the contents shown in the first embodiment, detailed description thereof is omitted.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.
For example, the purpose of use of a building that employs the steel frame 1 of each of the above embodiments is not limited.

In each of the above embodiments, the beam bracket 3 is extended from the column member 2 only in one direction. However, the beam bracket 3 extends in multiple directions (2 to 4 directions) with respect to one column member. It may be provided.
In addition, when the many beam brackets 3 are being fixed to the column member 2 from multiple directions, the cross-sectional shape of the main material 30 of each beam bracket 3 does not need to be the same.

  The welding of the haunches 31 and 32 to the main material 30 may be full penetration (complete penetration) welding or partial (partial penetration) welding.

DESCRIPTION OF SYMBOLS 1 Steel frame 2 Column member 3 Beam bracket 30 Main material 31, 32 Haunch (widening material)
4 Through diaphragm 5 Beam steel frame 6 Splice plate 7 High strength bolt P Column

Claims (2)

A pair of beam brackets respectively joined to a pair of columns;
A steel frame comprising a beam steel frame joined at both ends to the pair of beam brackets,
The beam bracket and the beam steel frame are friction bonded via a plurality of splice plates and a plurality of high strength bolts,
The beam bracket includes a main material having a web and a flange, and a widening material for widening the flange , and the length of the beam bracket extends from the column to the high-strength bolt of the flange located closest to the column. And
The flange splice plate is crimped with the flange sandwiched from above and below,
The widening member is made from a low yield point steel joined to a side surface of the flange, the splice of said flange of high-strength bolts the flanges extend to the beam steel side than that located on the most pillar side from said pillar A steel frame having a length applied to a plate, and the length of the widening material being equal to or less than the length of the main material . 2. The steel frame according to claim 1, wherein the widening member has a length in which a tip thereof is positioned in the vicinity of a high-strength bolt of the plurality of flanges from the column .

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