JP6460810B2 - Joint structure of steel column and reinforced concrete beam - Google Patents

Description

  The present invention relates to a joint structure between a steel column and a reinforced concrete beam.

  As is well known, a steel structure, a reinforced concrete structure, and a steel reinforced concrete structure are widely used in medium- and high-rise buildings because they are particularly excellent in strength as the structure of a housing of a building structure.

  Conventionally, in the above-mentioned building structure, as shown in FIGS. 9 and 10 are known as joining structures for joining a reinforced concrete beam to a steel column (for example, utility model 1, patent document 2, and patent document shown below). 3, Patent Document 4).

  FIG. 9 shows a state in which a reinforced concrete beam 91 is installed between steel columns 93 erected on the foundation. A part of the H-shaped steel 92 is embedded in the reinforced concrete beam 91. A main reinforcement 94 and a stirrup 95 are disposed on the reinforced concrete beam 91. In addition to the stirrup 95, a reinforcing stirrup 96 is disposed in a portion of the reinforced concrete beam 91, in particular, where the H-shaped steel 92 is embedded. A stud bolt 97 is welded to the flange of the H-shaped steel 92 in order to enhance the integrity with the concrete.

  In the structure of FIG. 9, the reinforced concrete beam 91 manufactured in advance in a factory or the like is brought to a position where it is joined to the steel column 93 at the construction site, and the shear plate 98 welded to the side surface of the steel column 93 is attached. The joint structure 90 of the steel column 93 and the reinforced concrete beam 91 is formed by bolting the web of the H-shaped steel 92 and welding the flange to the steel column 93.

  FIG. 10 shows a state in which the reinforced concrete beam 101 is installed between the steel columns 104 as in FIG. 9. One end of the H-section steel 102 is joined to the end of the reinforced concrete beam 101 via a plate-like body 103 welded thereto. A main bar 105 is disposed on the reinforced concrete beam 101, and the main bar 105 protrudes from the end of the reinforced concrete beam 101, passes through a through hole of the plate-like body 103, and is screwed with a nut 106.

  Also in the structure of FIG. 10, similarly to the structure of FIG. 9, the reinforced concrete beam 101 manufactured in advance in a factory or the like is brought to a position where it is joined to the steel column 104 at the construction site, and the side surface of the steel column 104 is obtained. The joint structure 100 of the steel column 104 and the reinforced concrete beam 101 is formed by bolting the web of the H-shaped steel 102 to the shear plate 107 welded to the steel plate and welding the flange to the steel column 104.

Japanese Utility Model Publication No. 5-49927 Japanese Patent No. 4490532 Japanese Patent Laid-Open No. 10-96294 Japanese Patent No. 2952366

  In the conventional joint structure 90 as described above with reference to FIG. 9, the main bar 94 of the reinforced concrete beam 91 is fixed by adhering to the concrete in the portion where the H-shaped steel 92 is embedded. It is necessary to lengthen the buried part. Further, since bending and shearing force are applied to the embedded portion of the H-shaped steel 92, reinforcement by the stirrups 95 and 96 and the stud bolt 97 is required. These can be factors that increase the manufacturing cost and make it difficult to place concrete concretely.

  In the conventional joint structure 100 as described above with reference to FIG. 10, the tensile force of the main bar 105 of the reinforced concrete beam 101 is transmitted via the plate-like body 103, so that the H-section steel 102 is at a position where a large bending moment acts. When joining the reinforced concrete beam 101 and the reinforced concrete beam 101, it is necessary to increase the thickness of the plate-like body 103, which may increase the manufacturing cost.

  Further, when the H-section steel 102 and the reinforced concrete beam 101 are joined at a position where the bending moment is small, such as in the vicinity of the inflection point, shear friction at the joint surface between the plate-like body 103 and the reinforced concrete beam 101 cannot be expected. , Shear key (stop) is required. When seismic loads are applied in addition to long-term loads, the design of the beam becomes very complicated because the reflex points of the beams move.

  An object of the present invention is to provide a joint structure between a steel column and a reinforced concrete beam, which is excellent in cost and ease of design, and capable of densely placing concrete.

The present invention employs the following means in order to solve the above problems. That is, the present invention is a joint structure of a steel column and a reinforced concrete beam, in which a steel-framed joint member is provided on a side surface of a steel column, and a reinforced concrete beam having a main reinforcement inside is joined to the joint member. Thus, the end of the main bar provides a joint structure between a steel column and a reinforced concrete beam that is welded to the joint member directly or via a coupler.
According to such a configuration, the main bar and the joint member can be welded directly or via a coupler to build a strong structure. The plate-like body 103 becomes unnecessary. Moreover, it is not necessary to lengthen the embedding part of the joint member in the reinforced concrete beam, that is, the joint member can be shortened. Thereby, manufacturing cost can be held down.
Moreover, the weight of the joining structure is reduced by reducing the amount of reinforcing bars. In addition, the workability is improved, for example, the joint member can be loaded with a small lifting machine.
Moreover, since the structure inside the reinforced concrete beam becomes simple, concrete can be placed densely.

The joint member is H-shaped steel, and the end of the main bar extending in the length direction of the reinforced concrete beam is along the surface of the flange or web of the joint member or the mouth of the joint member It may be arranged and fixed on the surface.
According to such a configuration, since the joint member is H-shaped steel, the shear force is transmitted by the concrete between the upper and lower flanges. Therefore, the joint member and the reinforced concrete beam are also located near the inflection point of the beam. A joint portion can be provided, and the design becomes easy. The design when the anti-curvature point of the beam moves is easy.
In addition, since the end of the main bar is arranged and fixed along the flange or web surface of the joint member or on the end face of the joint member, the connection strength between the main bar and the joint member is increased.

The reinforced concrete beam may have a plurality of the main bars, and each of the main bars may be fixed to the joint member at different positions in the length direction of the reinforced concrete beam.
According to such a configuration, even when the main bar arrangement density is increased, the main bar can be easily fixed to the joint member, and the design and construction can be easily performed while increasing the connection strength. It becomes possible.

The joint member is H-shaped steel, and the flange width of the joint portion of the joint member with the steel column is smaller than the flange width of the joint member on the side where the main bars are welded. Also good.
According to such a configuration, it is possible to form a plastic hinge at a portion where the flange width of the joint member is narrow while securing the flange width necessary for joining to the main bar, so that it is difficult to cause damage to other portions of the beam. It becomes possible. In addition, since the joint member is H-shaped steel, the shear force is transmitted by the concrete between the upper and lower flanges. Therefore, it is possible to provide a joint between the joint member and the reinforced concrete beam near the inflection point of the beam. It becomes possible and design becomes easy. The design when the anti-curvature point of the beam moves is easy.

The joint member is H-shaped steel, and at least one of the flanges of the joint member has a steel plate at an end portion on the welded portion side with the main reinforcing bar in a direction perpendicular to the length direction of the reinforced concrete beam. May be fixed.
According to such a configuration, it is possible to improve the compressive force transmission performance between the flange and the concrete and to prevent the concrete from being damaged. In addition, since the joint member is H-shaped steel, the shear force is transmitted by the concrete between the upper and lower flanges. Therefore, it is possible to provide a joint between the joint member and the reinforced concrete beam near the inflection point of the beam. It becomes possible and design becomes easy. The design when the anti-curvature point of the beam moves is easy.

 ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the joining structure of the steel column and the reinforced concrete beam which suppressed manufacturing cost.

  In a preferred mode, it is possible to easily design a joint structure between a steel column and a reinforced concrete beam.

  In a preferred embodiment, it is possible to provide a joint structure that facilitates the dense placement of concrete.

  In a preferred mode, it is possible to provide a joint structure with high workability.

  In a preferred embodiment, it is possible to provide a bonded structure that is less susceptible to damage.

It is the front view which carried out the partial cross section view of the joining structure of the steel column shown as embodiment of this invention and a reinforced concrete beam. It is a sectional side view of the joining structure of the steel column shown as the said embodiment and a reinforced concrete beam. It is the top view which carried out the partial cross section view of the joining structure of the steel column shown as the said embodiment, and a reinforced concrete beam. It is the front view which carried out the partial cross section view of the 1st modification of the joining structure of the steel column shown as the said embodiment, and a reinforced concrete beam. It is a sectional side view of the 1st modification of the joining structure of the steel column shown as the said embodiment, and a reinforced concrete beam. It is the top view which carried out the partial cross section view of the 2nd modification of the joining structure of the steel column shown as the said embodiment, and a reinforced concrete beam. It is the top view seen from the partial cross section of the 3rd modification of the joining structure of the steel column shown as the said embodiment, and a reinforced concrete beam. It is a sectional side view which shows the connection mode of the main reinforcement and the joint member in the joining structure of the steel column shown as the said embodiment, and a reinforced concrete beam. It is the front view which carried out the partial cross section view of the joining structure of the conventional steel column and a reinforced concrete beam. It is the front view which carried out the partial cross section view of the joining structure of the conventional steel column and a reinforced concrete beam.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial cross-sectional front view of a joint structure 1 of a steel column 2 and a reinforced concrete beam 3 shown as an embodiment of the present invention. FIG. 2 is a side sectional view of the bonding structure 1, and FIG. 3 is a plan view of the bonding structure 1 in a partial cross-sectional view.

  A shear plate 10 is fixed to a side surface of a steel column 2 made of a steel pipe column (including a CFT column) standing on a foundation or the like by welding or the like. In the joint structure 1, the web 4 c of the joint member 4 made of H-shaped steel is bolted to the shear plate 10 of the steel column 2, and the flanges 4 a and 4 b are welded to the side surface of the steel column 2 to join Has been. Further, the end portion of the joint member 4 opposite to the joint portion with the steel column 2 is embedded in the reinforced concrete beam 3.

  The reinforced concrete beam 3 includes a bar-shaped main reinforcing bar 5 so as to extend along the length direction of the reinforced concrete beam 3. The main reinforcement 5 is fixed to a portion of the joint member 4 embedded in the reinforced concrete beam 3 via a coupler 6. The coupler 6 is installed corresponding to each main reinforcement 5 and is welded to the joint member 4.

  A female thread portion is formed inside each coupler 6. A male thread portion is formed at the end of each main muscle 5. A lock nut 7 is screwed to each main bar 5 in advance, and each main bar 5 is screwed into a corresponding position inside the corresponding coupler 6, and then the lock nut 7 is screwed toward the coupler 6, so that the main bar 5 is attached to the coupler 6. It is fixed.

  Each coupler 6 is welded to the upper surface of the upper flange 4a of the joint member 4 and the lower surface of the lower flange 4b. Thereby, the end of the main bar 5 is arranged and fixed along the surfaces of the flanges 4 a and 4 b of the joint member 4.

  A gluteal muscle 8 is disposed outside each major muscle 5 so as to surround each major muscle 5.

  A stud bolt 9 is welded to the web 4 c of the joint member 4.

  Next, the construction method of the joining structure 1 shown in FIG. 1 will be described. In this construction method, the concrete of the reinforced concrete beam 3 is placed on site.

  First, the steel column 2 is erected on the foundation. Next, a shear plate 10 is formed by welding or the like at a portion of the steel column 2 where the reinforced concrete beam 3 is joined. The web 4c of the joint member 4 is fixed to the shear plate 10 by bolting, and the flanges 4a and 4b of the joint member 4 are fixed to the side surface of the steel column 2 by welding.

  Thereafter, the coupler 6 is fixed to the flanges 4a and 4b of the joint member 4 by welding, and the main bar 5 to which the lock nut 7 is screwed in advance is screwed into the corresponding coupler 6 to an appropriate position, and the lock nut 7 is coupled to the coupler 4 The main muscle 5 is fixed by screwing it toward 6. Along with this work, a formwork (not shown) is installed outside the main reinforcement 5 or the like. Finally, concrete is placed in the mold and the reinforced concrete beam 3 is constructed. The coupler 6 may be welded to the joint member 4 in advance at the factory.

  Next, the operation of the joint structure 1 between the steel column 2 and the reinforced concrete beam 3 as described above will be described.

  In this joint structure 1, the main reinforcing bar 5 of the reinforced concrete beam 3 is welded and fixed to the joint member 4 via the coupler 6, so that this fixed portion can apply the bending tensile force acting on the reinforced concrete beam 3 to the joint. It is reliably transmitted to the member 4.

  On the other hand, the bending compressive force is transmitted between the main bar 5 of the reinforced concrete beam 3 and the joint member 4 through the fixing portion, similarly to the bending tensile force. Further, the bending compressive force is transmitted by the bearing pressure between the compressed concrete of the reinforced concrete beam 3 and the end face of the joint member 4.

  Further, the shearing force is transmitted by the concrete sandwiched between the upper and lower flanges 4 a and 4 b of the joint member 4.

  Thus, in the joining structure 1 in this embodiment, since the main reinforcement 5 of the reinforced concrete beam 3 is welded to the joint member 4 via the coupler 6, it is like a conventional joining structure as shown in FIG. It is not necessary to lengthen the buried portion of the joint member 4 (H-shaped steel 92). That is, the joint member 4 is shortened so that only the minimum part necessary for stress transmission is provided. Just bury it.

  In addition, for the purpose of preventing buckling of a local portion of the flange, protecting the main reinforcement 5, or fireproof coating of the joint member 4, the above-described stress outside the flanges 4a and 4b of the joint member 4 is used. In addition to the parts required for transmission, concrete may be provided. Also in this case, since it is not necessary to consider the transmission of stress outside the region, reinforcement by stirrup is basically unnecessary, and the amount of reinforcing bars necessary for manufacturing can be reduced.

  Furthermore, in the joint structure 1 according to the present embodiment, the main bar 5 of the reinforced concrete beam 3 is welded to the joint member 4 via the coupler 6, so that the plate-like body of the conventional joint structure as shown in FIG. 103 is not required.

  For the various reasons described above, it is possible to suppress the steel material cost, that is, the manufacturing cost, while increasing the connection strength of the joint structure 1.

  By reducing the amount of reinforcing bars, the weight of the joint structure 1 is also reduced. Thereby, the workability is improved, for example, the joint member 4 can be loaded with a small lifting machine.

  Moreover, since the structure inside the reinforced concrete beam 3 is simplified, the concrete can be placed densely.

  In addition, when an external force is applied to the joint member 4 and the reinforced concrete beam 3, the shearing force generated between them is transmitted to the concrete between the upper and lower flanges 4a and 4b. Unlike the joint structure, it is possible to provide a joint portion between the joint member 4 and the reinforced concrete beam 3 near the inflection point of the reinforced concrete beam 3, and the design becomes easy. The design when the anti-curvature point of the beam moves is easy.

  As described above, since the reinforced concrete beam 3 is constructed after the joint portion 4 is joined to the steel column 2 in the construction of the joining structure 1, it is easy to absorb errors generated in the production of members and construction work. Also, a large lifting machine is not necessary. Therefore, the joining structure 1 is excellent in workability.

  Next, FIGS. 4 and 5 show a first modification of the above embodiment.

  In the first modification, a support plate 12 that is a steel plate is fixed to the lower flange 4b of the joint member 4 in a direction orthogonal to the length direction of the reinforced concrete beam 3 by welding. This is different from the basic configuration shown in FIG.

  According to such a configuration, it is possible to disperse the compressive stress when the bending compressive force acting on the wood face of the joint member 4 is large and the concrete of the reinforced concrete beam 3 may be damaged. Thereby, it can be made hard to produce the breakage of concrete.

  Even when the bearing plate 12 is installed in this manner, the bearing plate 12 only needs to withstand the compressive force acting between the joint member 4 and the reinforced concrete beam 3. A smaller one than the plate-like body 103 having a conventional joint structure as shown in FIG. Furthermore, the support plate 12 may be fixed to the joint member 4 by simple welding.

  The bearing plate 12 may be provided on the upper flange 4a, or may be provided on both the flanges 4a and 4b.

  Next, FIG. 6 shows a second modification of the above embodiment.

  In the second modification, the main bars 5 are fixed to the joint member 4 alternately at different positions in the length direction of the reinforced concrete beam 3. Other configurations are the same as the basic configuration shown in FIG.

  Since each main bar 5 is fixed to the joint member 4 at different positions in the length direction of the reinforced concrete beam 3 in an alternating manner, the number of the main bars 5 is increased and the arrangement density is increased. However, the connection between the main bar 5 and the joint member 4 is facilitated, and the design and construction can be easily performed while increasing the connection strength.

  Next, FIG. 7 shows a third modification of the above embodiment.

  In the third modification, the width of the flanges 4a and 4b at the joint portion of the joint member 4 with the steel column 2 is the width of the flange 4a and 4b on the side of the joint member 4 on which the main bar 5 is fixed. It is getting smaller. Other configurations are the same as the basic configuration shown in FIG.

  The width of the flange 4a, 4b of the joint portion 4 of the joint member 4 with the steel column 2 is smaller than the width of the flange 4a, 4b on the side of the joint member 4 to which the main bar 5 is fixed. Since the plastic hinge can be formed in a portion where the flange width of the member 4 is narrow, it becomes possible to prevent damage to other portions of the beam while securing the flange width necessary for joining to the main bar 5.

  In the joint structure 1 described in the above embodiment, each coupler 6 is welded to the upper surface of the upper flange 4a and the lower surface of the lower flange 4b of the joint member 4, but as shown in FIG. , Welding to the lower surface of the upper flange 4a, the upper surface of the lower flange 4b, the side surfaces of the flanges 4a and 4b, the side surfaces of the web 4c, the side surfaces of the flanges 4a and 4b and the web 4c, etc. May be.

  Further, the adjustment steel plate 11 may be sandwiched between the coupler 6 and the joint member 4 and welded. Thereby, even if it is a case where arrangement | positioning density is increased by increasing the number of the main reinforcing bars 5, the connection of the main reinforcing bars 5 and the joint member 4 becomes easy, and design and construction are easily performed while increasing the connection strength. It becomes possible.

  In addition, grout may be injected into the coupler 6 to fill the inner cavity of the coupler 6.

  In the joining structure 1 described in the above embodiment, the main reinforcing bar 5 is fixed to the joint member 4 via the coupler 6. However, the main reinforcing bar 5 is directly welded and fixed to the joint member 4. Also good.

  Moreover, in the joining structure 1 demonstrated by said embodiment, although the stud bolt 9 is welded to the web 4c of the joint member 4, when transmission of shearing force is performed only with concrete, this stud The bolt 9 may be omitted.

  Moreover, in the joining structure 1 demonstrated by said embodiment, although the concrete of the reinforced concrete beam 3 was laid in the field, it replaces with this, and the reinforced concrete beam 3 and the joint part 4 are beforehand set | placed by the factory etc. After joining, it may be transported and piled on the site and joined to the steel column 2. In this case, since the reinforced concrete beam 3 and the joint portion 4 can be joined in parallel with the construction of the structure, the construction time can be shortened.

  The steel column 2 is not limited to a steel pipe or a CFT column, and may be an H-shaped, built-in H-shaped (welded H-shaped steel), or a cross-H-shaped steel frame. Flange welding may be performed at the factory.

  Further, the joint member 4 may be not only a rolled steel material such as JIS size H-section steel but also a weld steel material such as a built-in H-section steel.

  The preferred embodiments of the present invention have been described in detail above. However, those skilled in the art will understand that various modifications and equivalent embodiments are possible from this. .

  Therefore, the scope of right of the present invention is not limited to this, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the claims are also included in the present invention.

1 Joint structure of steel column and reinforced concrete beam 2 Steel column 3 Reinforced concrete beam 4 Joint member 5 Main reinforcement 6 Coupler 7 Lock nut 8 Reinforcement 9 Stud bolt 10 Steel plate (shear plate)
11 Adjustment steel plate 12 Bearing plate

Claims (4)

A steel-framed joint member is provided on a side surface of the steel column, and a reinforced concrete beam having a main reinforcement inside is joined to the joint member.
The joint member is H-shaped steel, and the reinforced concrete beam has a plurality of main bars extending in a length direction of the reinforced concrete beam, and each end of the main bar has a length of the reinforced concrete beam. A joining structure of a steel column and a reinforced concrete beam, arranged along the surface of the same flange of the joint member at a different position in the direction and welded to the flange . Joint structure before Symbol Joint members, the width of the flange of the joint portion between the steel column, the the Joint member, smaller than the width of the main reinforcement is welded side flanges, according to claim 1. At least one of said flange pre-Symbol Joint member, the end of the welding portion side of the main reinforcement, in a direction perpendicular to the longitudinal direction of the reinforced concrete beam, steel sheet is fixed, according to claim 1 or 2. The junction structure according to 2 . The joining structure according to any one of claims 1 to 3, wherein the main reinforcement is fixed to the joint member with an adjustment steel plate interposed therebetween.

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