JP5441630B2 - RCS beam-column joint structure - Google Patents

Description

  The present invention relates to an RCS column beam connection structure in which a steel beam is bonded to a reinforced concrete column, and particularly to a reinforcing structure thereof.

  As shown in FIG. 16C, it is most effective to reinforce the RCS beam-column joint structure by surrounding the joint with a cover plate 28. In the example of the figure, the main bar 32 is passed through holes provided in the upper and lower flanges 22a and 22b at the portion embedded in the column of the steel beam 22, and the flanges 22a and 22b and the main bar 32 are joined by a nut 33 or the like. By doing so, we are trying to reinforce it. However, if the cover plate 28 is provided, the design does not fit well, and it is desired to develop a joint structure that can be sufficiently reinforced without providing the cover plate 28.

  As structures for reinforcing the joint without providing a cover plate, there are those shown in FIGS. 16 (A) and 16 (B). In the example of FIG. 16 (A), the H-section steel 30 is joined as a protrusion on the upper surface of the upper flange 22a at the portion embedded in the column in the steel beam 22. In the example of FIG. 16 (B), a plurality of channel steels 31 are joined as protrusions on the upper surface of the upper flange 22a at the portion embedded in the column in the steel beam 22.

JP-A-11-166267 JP-A-6-280304

  The reinforcing structure that joins the H-shaped steel 30, the groove-shaped steel 31, and the main bar 32 to the flanges 22a and 22b of the steel beam 22 at the joint portion without the cover plate is complicated in processing and construction. Thus, there is also a problem that cross-sectional defects occur in the flanges 22a and 22b of the steel beam 22. Moreover, since it becomes a load-bearing mechanism that resists by supporting pressure, the bending moment transmitted from the column beam cannot be transmitted directly to the joint. Furthermore, in order to increase the bearing strength, it is necessary to increase the reinforcement of the reinforced concrete at that portion and reinforce it.

  An object of the present invention is to provide an RCS column beam connection structure that can be sufficiently reinforced even if a cover plate is omitted, and that is easy to process and construct.

RCS Concrete Columns Beam structure of this invention, as its basic configuration, RCS concrete for joining the reinforcing bars Concrete pillars and steel beams which end or intermediate portion has a flange vertically embedded in said pillar In the beam-to-column connection structure, a hole embedded in the concrete of the column is located in a portion of the steel beam embedded in the column and located on the surface on the anti-web side of at least one of the upper and lower flanges. It has a configuration in which a perforated steel plate is fixed .
According to this configuration, since the perforated steel sheet is fixed to the portion of the steel beam embedded in the column and located on the surface on the side opposite to the web of the flange, the following effects can be obtained.
-Perforated steel sheet has a better fixing effect than stress transmission by reinforcing bars, and since the superior fixing effect of this perforated steel sheet is utilized, the protrusion length for reinforcement can be shortened compared to the case of using reinforcing bars. .
・ The design shear force of the beam-column joint can be reduced.
・ Complex processing to steel beams is unnecessary compared to other conventional examples. Moreover, there is no influence on the concrete placement space.
-The perforated steel sheet can be easily joined to the steel beam at the column beam joint.
・ There is no cross-sectional defect in the upper and lower flanges of steel beams unlike the conventional example.
For these reasons, in this RCS column beam connection structure, even if the cover plate is omitted, sufficient reinforcement is possible, and processing and construction are also easy.

According to a first RCS column-column connection structure of the present invention, in the basic configuration, the intermediate portion of the steel beam is embedded in the column, and the column core is embedded in the column of the steel beam. The perforated steel sheet is fixed on each side, and the perforated steel sheet is formed in a strip shape extending in the vertical direction.
In the case of this configuration, since the perforated steel plate has a strip shape extending vertically, a fixing force in the vertical direction is strongly obtained at the embedded portion of the perforated steel plate. Therefore, when a vertical bending moment is applied to the steel beam, the perforated steel plates on both sides of the column core can effectively transmit the force acting downward and the force acting upward to the column. Strong against bending moment acting on

According to a second RCS column-to-column connection structure of the present invention, in the basic configuration, a connection fitting having a connection hole is fixed to the upper surface of the upper flange in a portion embedded in the column of the steel beam by welding. The lower end of the strip-shaped perforated steel sheet extending in the vertical direction is joined to the connection fitting by a bolt using the joining hole.
In the case of this configuration, the connection fitting on the upper surface of the steel beam can be used as connection means such as a rope for lifting the steel beam at the time of construction, and the workability is excellent. In addition, a dedicated lifting bracket is not required.

According to a third RCS column-to-column connection structure of the present invention, in the basic configuration, a connection fitting having a connection hole is fixed to the lower surface of a lower flange in a portion embedded in the column of the steel beam by welding. The upper end of the strip-shaped perforated steel plate extending in the vertical direction is joined to the connection fitting by a bolt with the joint hole, and the bolt insertion hole of the perforated steel plate through which the bolt is inserted extends in the vertical direction. the hole.
In this configuration, the connection fitting on the lower surface of the steel beam can be used as a temporary jig when the steel beam is installed, the level can be adjusted, and the workability is excellent. In addition, a dedicated temporary jig is not required.

  The RCS column beam connection structure of the present invention is an RCS column beam connection structure in which a reinforced concrete column and a steel beam having a flange at the top and bottom and an end portion or an intermediate portion embedded in the column are bonded to each other. Since the perforated steel sheet embedded in the concrete of the column is fixed to the portion of the steel beam embedded in the column, the perforated steel plate embedded in the concrete of the column is fixed on the surface opposite to the web of at least one of the upper and lower flanges. Even if the plate is omitted, sufficient reinforcement is possible, and processing and construction are easy.

(A) is a front view of the RCS beam-column joint structure concerning one Embodiment of this invention, (B) is 1B-1B arrow directional cross-sectional view in (A). It is a disassembled front view of the column beam connection structure. It is explanatory drawing of the force which acts on the column beam connection structure. It is a front view of the RCS column beam connection structure concerning other embodiments of this invention. It is explanatory drawing of the force which acts on the column beam connection structure. It is a front view of the RCS beam-column connection structure concerning further another embodiment of this invention. It is a front view of the RCS beam-column connection structure concerning further another embodiment of this invention. It is a front view of the RCS beam-column connection structure concerning further another embodiment of this invention. It is explanatory drawing of the force which acts on each test body used for the proof stress experiment of the RCS beam-column joint structure in each said embodiment. It is explanatory drawing of one test body used for the said proof stress test. It is explanatory drawing of another one test body used for the said proof stress test. It is explanatory drawing of another one test body used for the said proof stress test. It is explanatory drawing of another one test body used for the said proof stress test. It is explanatory drawing of another one test body used for the said proof stress test. It is a front view of the experimental apparatus used for the said proof stress test. It is a perspective view of various conventional examples.

  An embodiment of the present invention will be described with reference to FIGS. This RCS column beam connection structure is a column beam connection structure in which a reinforced concrete column 1 and a steel beam 2 having flanges 2a and 2b on the upper and lower sides and having end portions or intermediate portions embedded in the column 1 are connected. is there. In the column 1, a plurality of main bars 13 and hoops 14 are embedded in the concrete 12 as reinforcing bars as shown in FIG. A perforated steel sheet 3 embedded in the concrete of the column 1 is fixed to a portion of the steel beam 2 embedded in the column 1, located on the surface of the flanges 2 a and 2 b on the opposite web side. That is, the perforated steel plate 3 is fixed to the upper surface of the upper flange 2a and the lower surface of the lower flange 2b. In this example, in FIG. 1 (B) showing a cross-sectional view taken along arrow IB-IB in FIG. 1 (A), a steel beam 2 extending in the left-right direction is embedded in the column 1 and the steel beam 2 extending in the front-rear direction. Then, the end is buried in the pillar 1. The steel beam 2 that extends in the front-rear direction has the same cross-sectional shape as the steel beam 2 that extends in the left-right direction, and its end surface is abutted against the steel beam 2 that extends in the left-right direction. Or, it is joined by bolt joining via a joint hardware (not shown). In this embodiment, a configuration example in which the periphery of the column beam joint is surrounded by the blocking plate 8 is shown.

  In the steel beam 2 in which the intermediate portion is embedded in the column 1, the perforated steel plate 3 is fixed on the both sides of the column core in the portion embedded in the column 1. These perforated steel plates 3 have a strip shape extending in the vertical direction, and are arranged so that the surfaces thereof are parallel to the longitudinal direction of the steel beam 2. The perforated steel sheet 3 is a kind of gibber. Thus, by making the perforated steel sheet 3 into a strip shape extending in the vertical direction, the fixing force in the vertical direction of the embedded portion of the perforated steel sheet 3 is strengthened, and the vertical bending moment M acts on the steel beam 2. Sometimes, the perforated steel sheet 3 on both sides of the column core can effectively transmit the downwardly acting force Np and the upwardly acting force Np to the column 1, and the bending moment M acting on the steel beam 2. And strong structure. FIG. 3 is an explanatory diagram of the acting force. Ns is a load acting in the horizontal direction by the bending moment M.

Also in the two steel beams 2 before and after the end portions are embedded in the column 1, strip-shaped perforated steel plates 3 that are positioned on both sides of the column core and extend in the vertical direction are fixed. Also in this case, the perforated steel plate 3 is arranged so that the surface thereof is parallel to the longitudinal direction of the corresponding steel beam 2.
In addition, both the steel beam 2 extending in the left-right direction and the steel beam 2 extending in the front-rear direction are provided so that the perforated steel plate 3 is perpendicular to the longitudinal direction of the perforated steel plate 3. Also good.

  On the upper surface of the upper flange 2a in the portion embedded in the column 1 of the steel beam 2, a connection fitting 4 having a joint hole 5 is fixed by welding. The lower end of the strip-shaped perforated steel plate 3 extending in the up-down direction is joined to the connection fitting 4 with the bolt 6 through the joining hole 5. Thereby, the perforated steel plate 3 is fixed to the upper surface of the upper flange 2 a via the joint fitting 4. In this case, as shown in FIG. 2, when installing the steel beam 2, the connection fitting 4 of the upper flange 2 a of the steel beam 2 can be used as a connection means for connecting a rope or the like for lifting the steel beam 2. A special lifting bracket is not required and the workability is excellent.

  The connection fitting 4 having the joint hole 5 is also fixed to the lower surface of the lower flange 2b in the portion embedded in the column 1 of the steel beam 2 by welding. By connecting the upper end of the strip-shaped perforated steel plate 3 extending in the vertical direction to the connection metal fitting 4 with the bolt 6 at the joint hole 5, the perforated steel plate 3 is connected to the upper surface of the lower flange 2 b via the joint metal fitting 4. Fixed to. In this case, the bolt insertion hole 7 through which the bolt 6 of the perforated steel plate 3 is inserted is a long hole extending in the vertical direction. In this case, as shown in FIG. 2, a strip-shaped perforated steel plate 3 extending in the vertical direction is embedded and fixed in advance at the upper end of the reinforced concrete column 1 on the lower side of the steel beam 2, and the upper end of the perforated steel plate 3 is attached to the steel frame. The steel beam 2 is installed on the reinforced concrete column 1 by joining to the connecting fitting 4 of the lower flange 2b of the beam 2 with a bolt 6. That is, when the steel beam 2 is installed, the connection fitting 4 of the lower flange 2b can also be used as a temporary jig, so that a dedicated temporary jig is not required. Moreover, since the bolt insertion hole 7 of the perforated steel plate 3 is a long hole extending in the vertical direction, the level of the steel beam 2 can be adjusted at the time of bolt joining, and the workability is excellent.

Thus, in this RCS column beam connection structure, the portion of the steel beam 2 embedded in the column 1 is positioned on the surface of the flange 2a, 2b on the opposite web side and embedded in the concrete of the column 1. Since the perforated steel sheet 3 is fixed, the following effects can be obtained. -Since the fixing effect by the perforated steel sheet 3 having a fixing effect superior to the stress transmission by the reinforcing bar is utilized, the protrusion length for reinforcement can be shortened compared to the case of using the reinforcing bar.
・ The design shear force of the beam-column joint can be reduced.
-Complicated processing to the steel beam 2 is unnecessary compared with other conventional examples. Moreover, there is no influence on the concrete placement space.
-The perforated steel sheet 3 is easily joined to the steel beam 2 at the column beam joint.
・ There is no cross-sectional defect in the upper and lower flanges of steel beams unlike the conventional example.
For these reasons, in this RCS column beam connection structure, even if the cover plate 8 is omitted, sufficient reinforcement is possible, and processing and construction are easy.

  4 and 5 show another embodiment of the present invention. In the RCS column beam connection structure, in the embodiment shown in FIGS. 1 to 3, the perforated steel plate 3 of the lower flange 2b of the steel beam 2 is omitted, and instead the dice shape is formed on the upper surface of the lower flange 2b. Or the dumpling-like concrete lump 9 is provided. Instead of the dice-shaped or dumpling-shaped concrete lump 9, an iron table or the like may be used. Other configurations are the same as those in the previous embodiment except that the cover plate 8 is omitted.

  In the case of this embodiment, when the perforated steel plate 3 of the lower flange 2b of the steel beam 2 is omitted, when a vertical bending moment is applied to the steel beam 2, it acts downward and upward. Although the efficiency of transmitting force to the column 1 is somewhat reduced, the structure remains strong against the bending moment M acting on the steel beam 2. FIG. 5 is an explanatory diagram of the acting force.

FIG. 6 shows still another embodiment of the present invention. In this RCS column beam connection structure, in the embodiment shown in FIGS. 1 to 3, a perforated steel plate extending in the vertical direction is used as a strip-shaped perforated steel plate 3 fixed to the upper surfaces of the upper and lower flanges 2a and 2b of the steel beam 2. 3A and a perforated steel plate 3B extending in the lateral direction are used in combination. For example, in the steel beam 2 in which the middle part is embedded in the column 1, the surface of the perforated steel plate 3 </ b> A extending in the vertical direction is the longitudinal direction of the steel beam 2 on both sides of the column core in the portion embedded in the column 1. Are arranged parallel to each other. The perforated steel sheet 3B extending in the lateral direction is a steel beam 2 in which an intermediate portion is embedded in the column 1, and is extended to both sides of the column core in a portion embedded in the column 1, and the surface thereof is the longitudinal direction of the steel beam 2. It is arranged along. In the illustrated example, both ends of the perforated steel plate 3B extending in the lateral direction extend to positions where they are in contact with the perforated steel plate 3A extending in the vertical direction on both sides. The perforated steel plate 3B extending in the lateral direction may be welded to the perforated steel plate 3A extending in the vertical direction on both sides of the perforated steel plate 3B, and the rigidity is improved by this welding. In this embodiment, the perforated steel plates 3A and 3B are directly welded to the flanges 2a and 2b of the steel beam 2, but may be fixed via the connection fitting 4 as in the previous embodiment. good. For example, the perforated steel sheet 3 </ b> A extending in the vertical direction may be arranged so that the surface thereof is orthogonal to the longitudinal direction of the corresponding steel beam 2. Other configurations are the same as those in the embodiment of FIGS. 1 to 3 except that the cover plate 8 is omitted.
In the case of this embodiment as well, as in the case of the embodiment of FIGS. 1 to 3, the cover plate is omitted and sufficient reinforcement is possible, and processing and construction are also easy.

  FIG. 7 shows still another embodiment of the present invention. In this RCS column beam connection structure, in the embodiment of FIG. 6, the perforated steel sheet 3 </ b> A extending in the vertical direction at the lower flange 2 b of the steel beam 2 is omitted. Other configurations are the same as those in the embodiment of FIG.

  In the case of this embodiment, when the perforated steel sheet 3A extending in the vertical direction of the lower flange 2b of the steel beam 2 is omitted, when a vertical bending moment is applied to the steel beam 2, the force acting downward Although the efficiency of transmitting the upwardly acting force to the column 1 is somewhat reduced, the structure remains strong against the bending moment acting on the steel beam 2. Instead of omitting the perforated steel plate 3A extending in the vertical direction of the lower flange 2b of the steel beam 2, the perforated steel plate 3A extending in the vertical direction of the upper flange 2a may be omitted.

  FIG. 8 shows still another embodiment of the present invention. In the RCS column beam connection structure, in the embodiment of FIG. 6, all of the perforated steel plates 3A extending in the vertical direction at the upper and lower flanges 2a, 2b of the steel beam 2 are omitted, and the perforated steel plates 3B extending in the lateral direction are omitted. Use only. Other configurations are the same as those in the embodiment of FIG.

  In the case of this embodiment, when the perforated steel sheet 3A extending in the vertical direction is omitted, when the vertical bending moment is applied to the steel beam 2, the force acting downward and the force acting upward are applied to the column 1. Although the transmission efficiency is somewhat reduced, the structure remains strong against the bending moment acting on the steel beam 2.

Next, the results of experiments conducted on how the RCS beam-column joint structure of the present invention affects the fracture properties, maximum proof stress, and hysteresis properties will be described.
Table 1 shows a list of specimens and Table 2 shows a list of proof stresses. In each table, “gibel” means “perforated steel plate”.

In this experiment, five test bodies shown in FIGS. 10 to 14 were prepared in order to investigate the effect of the perforated steel sheet on the column beam joint. In addition, each test body is designed so that the bearing failure is preceded.
The experimental variable is the mounting direction of the perforated steel sheet. The specimen shown in FIG. 10 (shown as No. 1 in the table) is a specimen without a perforated steel plate attached. Both the test body shown in FIG. 11 (shown as No. 2 in the table) and the test body shown in FIG. 12 (shown as No. 3 in the table) both have a perforated steel plate that is parallel to the flange (sideways). A shear type. Among them, the specimen (No. 2) shown in FIG. 11 has shear reinforcement bars concentrated on the upper and lower surfaces of the flange of the steel beam as shown in the overall diagram at the lower left in the figure. In the test body (No. 3) shown in FIG. 12, the reinforcing bars 15 in the example of FIG. 11 are eliminated. The test body shown in FIG. 13 (shown as No. 4 in the table) is a test body in which a perforated steel plate is vertically attached to a flange (extending vertically) to form a bending die. The test body shown in FIG. 14 (shown as No. 5 in the table) is a test body in which the test body of FIGS. Using these as experimental variables, the effect of perforated steel sheet on the beam-column joint was investigated. Only No.2 and No.4 specimens have shear reinforcement bars concentrated on the upper and lower surfaces of the steel beam flange. The specimen is made to have a predetermined size by attaching an auxiliary beam. In each test body, the steel beam web panel thickness is set to 16 mm so that the beam-column joint is not shear broken. FIG. 15 shows the experimental apparatus used for this experiment.

The strength design of the perforated steel sheet was calculated as shown in FIG. Here, Q _s is
Calculation was performed as _{Q s = 1.08σ B · 2 ·} (π · d 2/4). As Q _b , the experimental value in the case of eccentric tension of the “tensile fracture property of perforated steel plate gibber” conducted by the experimenter prior to this experiment was used.

  From the experimental results shown in Tables 1 and 2, it can be seen that according to the RCS beam-column joint structure of the present invention, sufficient reinforcement is possible even if the cover plate is omitted. Further, in the experimental results, among the test bodies No. 1 to 5, the test bodies No. 1 to No. 3 all have experimental values within the allowable range with respect to the calculated shear strength. In the No. 4 and No. 5 specimens, the experimental value is larger than the calculated shear strength. From this result, it can be seen that the use of a vertically long (up and down) perforated steel sheet as in No. 4 and No. 5 specimens actually has a greater effect of improving shear strength. I understand.

DESCRIPTION OF SYMBOLS 1 ... Reinforced concrete pillar 2 ... Steel beam 2a, 2b ... Flange 3, 3A, 3B ... Perforated steel plate 4 ... Connection metal fitting

Claims (5)

In a steel reinforced concrete column beam connection structure that joins a reinforced concrete column and a steel beam having an upper or lower flange and an end or middle portion embedded in the column,
In the portion embedded in the column in the steel beam, located on the surface on the anti-web side of at least one of the upper and lower flanges, and fix the perforated steel plate embedded in the concrete of the column , The intermediate portion of the steel beam is embedded in the column, and the perforated steel plate is fixed on each side of the column core in a portion of the steel beam embedded in the column, and the perforated steel plate is RCS column beam connection structure in the form of a strip extending in the vertical direction . In a steel reinforced concrete column beam connection structure that joins a reinforced concrete column and a steel beam having an upper or lower flange and an end or middle portion embedded in the column,
In the portion embedded in the column in the steel beam, located on the surface on the anti-web side of at least one of the upper and lower flanges, and fix the perforated steel plate embedded in the concrete of the column, A connection fitting having a joint hole is fixed to the upper surface of the upper flange in the portion embedded in the column of the steel beam by welding, and the lower end of a strip-shaped perforated steel plate extending in the vertical direction is attached to the connection fitting. The RCS column beam joint structure joined with a bolt in the joint hole. In claim 1, the intermediate portion of the steel beam is embedded in the column, and the perforated steel sheet is fixed on each side of the column core in a portion embedded in the column in the steel beam, These perforated steel plates are formed in a strip shape extending in the vertical direction, and a strip extending in the vertical direction is fixed to the upper surface of the upper flange in the portion embedded in the column of the steel beam by welding. RCS column beam connection structure in which the lower end of a perforated steel plate is joined to the connection fitting with a bolt at the joint hole. In a steel reinforced concrete column beam connection structure that joins a reinforced concrete column and a steel beam having an upper or lower flange and an end or middle portion embedded in the column,
In the portion embedded in the column in the steel beam, located on the surface on the anti-web side of at least one of the upper and lower flanges, and fix the perforated steel plate embedded in the concrete of the column, A connection fitting having a joint hole is fixed to the lower surface of the lower flange in a portion embedded in the column of the steel beam by welding, and the upper end of a strip-shaped perforated steel plate extending in the vertical direction is connected to the connection fitting. An RCS column beam connection structure in which the bolt insertion hole of the perforated steel plate through which the bolt is inserted is a long hole extending in the vertical direction.   The upper end of a strip-shaped perforated steel plate extending in the vertical direction according to claim 1, wherein a connection fitting having a joint hole is fixed to a lower surface of a lower flange in a portion embedded in the column of the steel beam by welding. RCS column beam connection structure in which the bolt insertion hole of the perforated steel plate through which the bolt is inserted is a long hole extending in the vertical direction.

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