JP3742590B2 - Column / beam joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a column / beam connection structure between a steel column and a steel beam using a split tee, and more particularly to a column / beam connection structure that absorbs energy during an earthquake by bending and yielding a flange of a split tee in advance. .
[0002]
[Prior art]
In the column / beam connection structure between a steel column and a steel beam, the original method is to design the beam to yield before the column in the event of a large stress such as a large earthquake. This is because if the column is damaged during the action of a large stress, it is difficult to repair the building, and thus it is necessary to rebuild the entire area.
[0003]
However, in many cases, the yield point of the steel material of the beam is managed only at the lower limit, and in fact, the proof strength of the beam may be too large. Destruction may occur at the site. For example, when the steel beam and the steel column are fixed directly by welding, the welded portion between the steel column and the steel beam becomes a critical part when a large stress is applied, and the fracture occurs. In this case, since the steel beam and the steel column are welded, the column is often damaged.
[0004]
[Problems to be solved by the invention]
For this reason, the conventional column / beam joint structure prevents damage to the pillars by absorbing the energy during the earthquake by yielding the parts other than the pillars before the pillars so that the building can be restored even in the event of a large earthquake. Proposals have been made.
[0005]
For example, Japanese Patent Laid-Open No. 11-229493 discloses reinforcement of a column / beam joint structure using a split tee, and Japanese Patent Laid-Open No. 7-102635 is an improvement in earthquake resistance of a column / beam joint structure using a split tee. About. However, in the case of the above prior art, the flange bending strength of the split tee becomes critical in design, so that the thickness and width of the split tee are increased, which is uneconomical. As the split tee flange is bent, the bolt is subjected to bending tension, and the tensile fracture of the bolt becomes the final collapse system. In the case of such a tensile break of the bolt, the column may also be damaged by being pulled.
[0006]
Japanese Patent Application Laid-Open No. 2001-32369 discloses a conventional technique that uses an energy absorbing member by causing the bending yield of a split tee flange to precede the tensile yield of a bolt. However, this prior art is effective when the split tee web is subjected to tension, but there is room for improvement in that energy absorption cannot be expected when the web is compressed.
[0007]
On the other hand, JP-A-8-4112, JP-A-2000-192547, and JP-A-8-151686 disclose a column / beam joint structure in which an energy absorbing mechanism is provided in the vicinity of the end of a steel beam. Yes.
However, when notches are formed on both sides of the upper and lower flanges in the vicinity of the end of the H-shaped steel beam to positively yield the H-shaped steel beam and absorb energy (Japanese Patent Laid-Open No. 8-4112) In some cases, the beam breaks, so the repair work after a large earthquake becomes very large. Moreover, in the case of Unexamined-Japanese-Patent No. 2000-192547 and Unexamined-Japanese-Patent No. 8-151686, the energy absorption mechanism is being fixed to the column by welding. Therefore, it is actually difficult to replace an energy absorption mechanism that cannot be reused due to a large earthquake.
[0008]
The present invention has been made in view of the above-mentioned disadvantages of the prior art, and its purpose is a column / beam joint structure that absorbs energy in the event of a large earthquake by bending yielding of the flange of a split tee, and can be easily replaced. In addition, the present invention provides a column / beam joint structure capable of effectively absorbing energy not only when the web is pulled but also when the web is compressed.
[0009]
[Means for Solving the Problems]
A first invention is a column / beam joint structure in which a split tee 1 is bolted to a steel column 2 by a flange 1a, and a steel beam 3 is assembled to a web 1b of the split tee 1 to be bolted. Column / beam joint structure that absorbs the energy of earthquakes by bending and yielding the flange 1a ahead of other parts, and a thin part is provided by reducing the thickness of part of the flange of the split tee. In addition, the thin wall portion is thinned by reducing the thickness on the opposite side to the split tee web, and the outer surface of the thin wall portion on the opposite side of the web from the outer surface of the flange portion to be bolted and the thin wall portion. the inner corner portion formed by the outer surface, arcuate cross-section portion is provided over the flange entire width, the upper limit of the yield point control value of the split tee 1 lower limit Between the both ends of the split tee flange 1a and the steel column 2 with a spacing member (4, 9) interposed between the split tee flange 1a and the steel column 2 Are joined together with a gap.
In the split tee 1 used in the first invention, it is preferable to partially reduce the cross-sectional area of the flange 1a.
[0010]
In the second invention, two split tees (1, 5) are bolted with flanges at intervals above and below the steel column 2, and a steel beam is assembled between the webs of these split tees (1, 5). In the pillar / beam joint structure formed by bolting, the upper / lower pillar / beam joint is the pillar / beam joint structure according to claim 1 or 2, wherein the other pillar / beam joint is the other pillar / beam joint structure. A split tee 5 having a yield point higher than the upper limit of the yield point of the split tee 1 of one column / beam joint is used as the beam joint.
In the second invention, a concrete slab is placed on the beam mounting surface of the other column / beam joint (the column / beam joint opposite to the column / beam joint in the first invention). Also good.
In the third invention, in the column / beam joint structure according to any one of the above inventions, the steel column is a square steel tube column, the spacing member is an L-shaped spacing member, and the rectangular steel tube column. An L-shaped interval holding member is attached to each corner of the L-shaped interval holding member, and a split tee is bolted from above each L-shaped interval holding member.
In the fourth invention, in the column / beam joint structure according to any one of the above inventions, the steel column is an H-shaped steel column, and the spacing member is an L-shaped spacing member. Two pairs of L-shaped metal fittings facing each other are joined to the inside of the flange of the H-shaped steel column with a space in the vertical direction, and one pair of L-shaped spacing members are connected from the outside of the flange of the H-shaped steel column. Two sets are arranged so as to overlap with the L-shaped metal fittings, and split tees are bolted from above each L-shaped interval holding member.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments or reference embodiments of the present invention will be described below with reference to the drawings. The reference form shown in FIG. 1A is a column / beam connection structure of a square steel pipe column 2 a and a steel beam (H-shaped steel beam) 3. Split tees 1 and 5 are respectively arranged at the top and bottom of the H-shaped steel beam 3 at the end of the H-shaped steel beam 3, and the split tee webs 1b and 5b and the H-shaped steel beam 3 are bolted together. The upper and lower split tees 1 and 5 are bolted to the square steel pipe column 2a at the two upper and lower portions of the flanges 1a and 5a, and the square steel pipe column 2a and the H-shaped steel beam 3 are connected.
[0012]
Here, in the lower column / beam junction (one column / beam junction) of the H-shaped steel beam 3, there is a seat between the both ends of the flange 1 a of the split tee 1 and the bolt junction between the steel columns 2. A plate 4 (interval holding member) is inserted. And the press board 8 is arrange | positioned on the outer side of the bolt junction part of the flange 1a, and the volt | bolt is screwed together from the outer side of the press board 8. FIG.
[0013]
That is, as shown in FIG. 1B, in the lower column / beam joint, the seat plate 4 is inserted into both ends of the flange 1a of the split tee, and the flange 1a and the steel column are inserted in the center of the flange 1a. 2 is configured to have a gap. Therefore, even when an excessive stress is applied in the compression direction of the split tee web, the split tee flange 1a and the steel column 2 have a gap, so that energy can be absorbed by the split tee 1 and the column is damaged. There is no such thing. In addition, in FIG.1 (b), the state which the flange 1a plasticized to the tension | pulling side or the compression side is shown with a dashed-two dotted line.
[0014]
Further, in the split tee 1 of the lower column / beam joint (one column / beam joint), the upper limit value of the yield point management value is set to within twice, preferably within 1.3 times the lower limit value. ing. In the present invention, the flange 1a of the split tee 1 at the lower column / beam joint is bent and yielded prior to the bolt 6 and the H-shaped steel beam 3 that are fastened to the steel column, so that the flange 1a is plasticized. Can absorb the energy at the time of earthquake and can quantify the beam end rotation angle. As a result, the effect of reducing the response to earthquakes and winds can be enhanced, and it is possible to prevent collapse at an undesired site such as a tensile failure of a bolt.
[0015]
In addition, the split tee 1 at the lower column / beam junction partly reduces the cross-sectional area of the flange, and more reliably precedes the bolt 6 and the H-shaped steel beam 3 that are fastened to the steel column. It is preferable that the flange 1a bend and yield. Specifically, (A) a part of the flange is reduced in thickness to be thinned, and the outer surface of the thin part is opposite to the web, and the outer surface of the flange part to be bolted and the outer part of the thin part. In the inner corner formed by the above, when the cross-section arc-shaped portion is provided over the entire width of the flange [see FIG. 2 shown as an embodiment of the present invention ], (B) when notches are formed on both sides of the flange [FIG. 3), (C) When the hole is opened in the flange [see FIG. 4], and the like. In addition, the form of the thin part 1c, the notch part 1d, and the opening 1e which were illustrated can be changed suitably.
[0016]
On the other hand, the flange 5a of the split tee 5 and the H-shaped steel beam 3 are directly bolted to each other at the upper column / beam junction (the other column / beam junction) of the H-shaped steel beam 3. The split tee 5 of the upper column / beam joint has a yield point higher than the upper limit of the yield point of the split tee 1 of the lower column / beam joint.
[0017]
In other words, in the present invention, the split tee 1 managed at the lower yield point is surely bent and yielded prior to the split tee 5 having the upper high yield point. Therefore, the damage due to the energy at the time of the earthquake is first concentrated on the split tee 1 of the lower column / beam joint. Even when the split tee 1 at the lower column / beam joint becomes unusable after the earthquake, the split tee 1 can be replaced to recover the earthquake resistance as a building. Since the split tee 1 is bolted together, the replacement work is very easy.
[0018]
Note that a concrete slab may be placed on the upper side of the H-shaped steel beam 3 (the mounting surface of the beam at the other column / beam joint) [not shown]. Also in this case, since the split tee 1 to be replaced is on the lower side where the concrete slab is not placed, the replacement work of the split tee 1 is not hindered.
[0019]
5 and 6 show an example using an L-shaped interval holding member 9 in which two orthogonal surfaces have the same size, and bolt holes are formed on each surface.
In the case of FIG. 5, a plurality of split tees 1 (four in the figure) are attached to the four vertical surfaces of the square steel pipe column 2a at the same height. In this example, the above-mentioned L-shaped interval holding member 9 is attached to each of the four corners of the square steel pipe column 2a, and the split tee 1 is bolted from above the L-shaped interval holding member 9. To do.
[0020]
Moreover, in the case of FIG. 6, the split tee 1 is attached between the flanges of the H-shaped steel column 2b. In this example, first, two pairs of L-shaped metal fittings 10 facing inwardly are joined to the inside of the flange of the H-shaped steel column 2b at intervals in the vertical direction. Two pairs of L-shaped interval holding members 9 are arranged so as to overlap the L-shaped metal fitting 10 from the outside of the flange of the H-shaped steel column 2b. The split tee 1 is bolted from above.
[0021]
【The invention's effect】
The column / beam joint structure of the present invention is provided with a thinned portion by reducing the thickness of a portion of the flange of the split tee, and the thinned portion is reduced in thickness on the side opposite to the web of the split tee, On the outer surface opposite to the web in the thin wall portion, an inner corner formed by the outer surface of the flange portion to be bolted and not reduced in thickness and the outer surface of the thin wall portion is provided with an arc-shaped section across the entire width of the flange. Therefore, when an excessive stress is applied in the direction of compression / tension of the beam during an earthquake, etc., the thin part of the flange of the split tee of one column / beam joint is connected to the steel column with a bolt or H Bending and yielding more reliably before the steel beam. Therefore, the energy at the time of earthquake is absorbed by the plasticization of the flange, and thereby the response reduction effect against earthquakes and winds can be enhanced.
[0022]
In addition, the column / beam joint structure of the present invention is capable of quantifying the beam end rotation angle because the split tee flange of one column / beam joint precedes and yields. The later split tee can be easily replaced. Thereby, collapse at an undesired part such as a tensile fracture of the bolt can be prevented.
[0023]
In particular, even when excessive stress is applied in the compression direction of the split tee web, the column-beam connection structure of the present invention has a gap between the flange of the split tee and the steel column, so that energy is absorbed by the split tee. Yes, the pillars are not damaged.
[0024]
The column / beam joint structure of the present invention can recover the earthquake resistance performance as a building by replacing the split tee even when the split tee of the lower column / beam joint becomes unusable after the earthquake. Moreover, since the split tee is joined by bolts, the replacement work is very easy.
[0025]
The column / beam joint structure of the present invention can avoid brittle fracture in the event of a large earthquake by not using welding for the junction between the column and split tee and the energy absorption mechanism of the split tee, and has high earthquake resistance. Can be built.
[Brief description of the drawings]
FIG. 1 (a) is a side view showing a column / beam joint structure of a reference form , and FIG. 1 (b) shows a lower column / beam joint (one column / beam joint) in FIG. It is the shown perspective view.
FIG. 2 (a) is a perspective view showing a split tee in which a part of the flange is thinned to reduce the thickness, and FIG. 2 (b) is a side view of (a).
3A is a perspective view showing a split tee with notches formed on both sides of a flange, and FIG. 3B is a front view of FIG. 3A.
4A is a perspective view showing a split tee opened in a flange, and FIG. 4B is a front view of FIG. 4A. (C) is a cross-sectional view taken along the line AA of (b).
FIG. 5 is a view showing a reference form of an attachment example when a split tee is attached to a square steel pipe column in the column / beam joint of the present invention.
FIG. 6 is a view showing a reference form of an example of attachment when a split tee is attached between flanges of an H-shaped steel column in the column / beam joint of the present invention.
[Explanation of symbols]
1 Split tee 1a Flange 1b Web 1c Thin part 1d Notch 1e Open hole
1f Bolt insertion hole 2 Steel column 2a Square steel pipe column 2b H-shaped steel column 3 H-shaped steel beam (steel beam)
4 Seat plate (spacer holding member)
5 Split tee 5a Flange 5b Web 6 Bolt 7 Nut 8 Holding plate 9 L-shaped spacing member 10 L-shaped bracket 11 Cross-section arc-shaped part

Claims (6)

In a column / beam joint structure in which a split tee is bolted to a steel column with a flange, and a steel beam is assembled to the split tee web and bolted, the energy of the earthquake is obtained by bending and yielding the split tee flange. Column / beam joint structure that absorbs the thickness of the split tee, and a part of the split tee flange is thinned to provide a thin part, and the thin part is thinned on the side opposite the split tee web. Further, on the outer surface side opposite to the web in the thin-walled portion, the inner corner formed by the outer surface of the flange portion to be bolted and not thinned and the outer surface of the thin-walled portion has a cross-sectional circle over the entire width of the flange. arc-shaped portion is provided, the upper limit of the yield point control value of the split tee is set within twice the lower limit, and the spray Columns and beams characterized in that a spacing member is inserted between the bolt joints of both ends of the flange of the tea tee and the steel column, and the flange of the split tee and the steel column are joined with a gap. Junction structure.  2. The column / beam joint structure according to claim 1, wherein a split tee with a partially reduced flange cross-sectional area is used.  In a column / beam joint structure in which two split tees are bolted with flanges at intervals above and below the steel column, and a steel beam is assembled between the split tee webs and bolted together, either up or down The column / beam joint is the column / beam joint structure according to claim 1 or 2, wherein the other column / beam joint has a split tee yield of one column / beam joint. A column / beam joint structure using a split tee with a yield point higher than the upper limit value.  4. The column / beam joint structure according to claim 3, wherein a concrete slab is placed on the beam mounting surface of the other column / beam joint. The steel column is a square steel pipe column, and the spacing member is an L-shaped spacing member, and an L-shaped spacing member is attached to each corner of the rectangular steel tube column with an interval in the vertical direction. 5. The column / beam joint structure according to claim 1, wherein split tees are bolted from above each L-shaped spacing member. The steel column is an H-shaped steel column, the spacing member is an L-shaped spacing member, and a pair of inwardly facing L-shaped metal fittings are vertically arranged inside the flange of the H-shaped steel column. Two sets are joined at an interval, and two pairs of L-shaped interval holding members are arranged so as to overlap the L-shaped metal fittings from the outside of the flange of the H-shaped steel column, and each L-shaped interval is maintained. The column / beam joint structure according to any one of claims 1 to 4, wherein the split tee is bolted from above the member.

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