JP2001262707A - Junction structure for reinforced concrete column and steel beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a junction structure for a reinforced concrete column and a steel beam capable of improving concrete fillability improving rigidity and proof strength of a junction part between the reinforced concrete column and the steel beam, and improving construction workability and economy. SOLUTION: An outer circumferential side surface 1a of a beam junction part of a reinforced concrete column 1 is enclosed by a short steel pipe 2 for junction of a beam, and a steel beam 3 is jointed with the short steel pipe 2 through a beam joint member 4. The short steel pipe 2 to the beam joint member 4 and the beam joint member 4 to the steel beam 3 are jointed not by welding but by high strength bolts 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a column and a beam applied to a structure in the field of, for example, construction or civil engineering, and more particularly to a reinforced concrete column (hereinafter referred to as RC column) and a steel beam (S). The present invention relates to a joint structure between a reinforced concrete column and a steel beam, which can enhance rigidity and proof stress, economic efficiency and workability at a column-to-beam joint portion with a beam.

[0002]

2. Description of the Related Art In recent years, in order to reduce the weight of a main body frame member and the labor required for assembling a frame as a result of a reduction in the weight of a structure, for example, different types of RC beams and S beams such as H-beams are used. A mixed structure frame obtained by joining inter-members has been put to practical use.

[0003] With respect to such a mixed structure frame,
For example, "Pillar R" issued by the Architectural Institute of Japan in December 1994
As described in “Symposium on Mechanical Behavior of Column-Beam Joint of Mixed Structure with C / Beam S” (see page 137), from the viewpoint of structural rationality by joining dissimilar members, A form in which the RC column is continuously inserted through the joint, a form in which the S beam is discontinuously assembled in the RC column, or a stiffener or reinforcement in the joint of the RC column Various details have been researched and developed, such as the form of assembling lumber.

[0004] By the way, when a column-beam joint between an RC column and an S beam is subjected to a horizontal external force during an earthquake, for example, severe stress due to tensile force or compressive force acts on the joint.
Since a large shear force is generated, the beam-column joint of the RC column to which the S-beam is joined is reinforced by wrapping it with a short steel pipe for beam joining.

[0005] However, the column-beam joint described above has three major technical problems. The first technical problem is that when a stiffener or a reinforcing material is attached to a joint made of short steel pipes by welding, machining and assembling operations are increased, and correction work is also required. Which requires
This is a point that the processing cost increases. A second technical problem is a problem of filling concrete into short steel pipes. In particular, in the case where the S beam has an assembling form in which the S beam is continuously inserted through the short steel pipe, when concrete is launched from the lower side of the short steel pipe, the dead space formed inside the flange of the S beam is reduced. The point is that the filling property of the concrete is poor and cavities are easily formed. Also, in the case where the S beam is welded to the outer periphery of the short steel pipe and is discontinuously assembled, similarly, a dead space is formed inside the stiffener or the reinforcing material assembled in the short steel pipe. Therefore, a cavity is easily formed. A third technical problem is a structural performance problem of the short steel pipe. In particular, in the case where the welded portion to the short steel pipe has a wide variety of assembling forms, brittle fracture is likely to occur at the welded portion, although it depends on the welding quality.

[0006] Such problems of processing cost, concrete filling property, brittle fracture at a welded portion, and the like increase the workability and economical efficiency in disseminating a mixed structure frame including RC columns and S beams. It is a major obstacle for

Conventionally, for example, Japanese Utility Model Publication No. 61-34404 (hereinafter referred to as prior art 1) or Japanese Patent Application Laid-Open No. 11-34404.
There is one having a column-beam joint structure as disclosed in Japanese Patent Application Laid-Open No. 100900 (hereinafter referred to as Prior Art 2) and the like. As shown in FIG. 11, the joint structure of a column and beam described in Prior Art 1 embeds a rectangular short steel pipe c for beam joining in a beam joining portion surrounded by a main reinforcement b of a rectangular RC column a. Short steel pipe c
A flange joint end of an S beam d made of H-section steel is fastened and fixed to each outer peripheral side by a high-strength bolt f via a bracket e.

[0008] However, the prior art 1 described above has a structure in which a beam joint portion wrapped around a main bar b forming an RC column a has an S column.
After arranging the short steel pipe c to which the beam d is joined in advance, concrete is cast, so that the joint end of the short steel pipe c and the S beam d is buried at the same time as the concrete of the RC column a. Thereby, the RC column a and the S beam d are completely integrated, and the concrete filling resistance due to the flange end of the short steel pipe c and the S beam d embedded in the RC column a is large, and the concrete filling is performed. Reduce the nature. Moreover, R
In order to properly arrange the hoop reinforcing member that restrains the main reinforcing bar b that secures the shearing force of the C-column a and secures the deforming ability as a member at the beam joining site, the hoop penetrating through the web of the S beam d is inserted. It is necessary to open a hole. This allows
Drilling requires a great deal of work, and increases the processing cost.

On the other hand, as shown in FIG. 12, the joint structure of a column and a beam described in Prior Art 2 encloses the outer periphery of a beam joint portion of a rectangular RC column a with a rectangular short steel pipe c. A cruciform plate-shaped diaphragm g formed by cutting and forming a steel plate is welded to the upper and lower ends of c. Further, a flange joint end of an S beam d made of H-section steel is butt-welded to each joint end of the diaphragm g, and its web joint end is welded to the outer peripheral side surface of the short steel pipe c. The main reinforcement b forming the RC column a is inserted into the short steel pipe c through each corner space of the diaphragm g, and at the same time when the RC column a is poured into the concrete, the concrete is filled in the short steel pipe c. It has become so.

[0010]

However, in the column-beam joint structure described in Prior Art 2 described above, since the diaphragm g has a wide cross-shaped flat plate shape, the concrete filling property is reduced. Further, since the short steel pipe c and the diaphragm g and the connection between the diaphragm g and the S beam d are welded, the short steel pipe c is pulled or compressed by the S beam d, or the weight or twist of the S beam d itself. When a severe stress such as a bending moment or the like is transmitted, the displacement of the short steel pipe c increases. With the accompanying shear stress, S
The welded portion of the beam d is easily broken, and the concrete filled in the short steel pipe c is easily broken by bearing pressure. This allows
The rigidity and proof stress of the beam-column joints decrease.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in consideration of the above circumstances, and has been made to improve the concrete filling property and to improve the rigidity and strength of a joint portion between a reinforced concrete column and a steel beam. An object is to provide a joint structure with a beam.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention encloses the outer peripheral side surface of a beam-joining portion of a reinforced concrete column member with a relatively thick short steel pipe for beam-joining. Provided is a joint structure between a steel beam and a reinforced concrete column in which a beam joint member is joined to a steel pipe and a steel beam member is joined to the beam joint member.

Here, in the present invention, the beam joining member has a form such as a split tee or an angle, and a joint portion between the short steel pipe and the beam joining member and a joint portion between the beam joining member and the steel beam member. It is joined by non-welding with high strength bolts, and the length of the short steel pipe is 1.1 to the height of the steel beam member.
It is preferable to set within the range of 3.0 times.

Further, it is preferable that a reinforcing member is cross-linked by non-welding to a portion corresponding to the beam joint member in the short steel pipe, and is joined. In this case, it is preferable that the reinforcing member has a cross shape.

That is, according to the present invention, with the above configuration, the beam joining portion of the reinforced concrete column member is enclosed by a relatively thick short steel pipe, and the steel beam member is joined to the outer peripheral side surface of the short steel pipe. Beam joint members
It is possible to use the short steel pipe as a formwork, and it is possible to completely eliminate the factors that hinder the concrete filling property as in the past. In addition, since the joint between the short steel pipe, the beam joint member, and the steel beam member is a non-welded joint structure using high-strength bolts, the welded portion can be minimized, and a defect that becomes the starting point of breakage due to welding as before. It is possible to eliminate the part, to reduce the processing cost and to improve the structural reliability. Furthermore, by setting the length of the short steel pipe within a range of 1.1 to 3.0 times the height of the steel beam member, the strength of the beam joint can be improved. Furthermore, a large force to be transmitted from the steel beam member by bridging and reinforcing a reinforcing member having a cross shape at a portion corresponding to the beam joint member in the short steel pipe by non-welding with a high strength bolt. , It is possible to prevent cross-sectional deformation of the short steel pipe.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings shown in FIGS.
1 to 5 show a first embodiment of a joint structure between a reinforced concrete column and a steel beam according to the present invention.

As shown in FIG. 1 and FIG.
On the outer peripheral side surface 1a of the beam joining portion of the C column 1, a relatively short-walled rectangular short steel pipe 2 for beam joining is provided in an outer envelope state.
An H-beam S beam 3 is joined to each outer surface 2 a of the short steel pipe 2. Each S beam 3 has T as in the illustrated embodiment.
It is joined to each outer side surface 2a of the short steel pipe 2 via a beam splicing member 4 made of a letter-shaped split tee or an angle (not shown) or the like. The beam splicing members 4 are arranged above and below each outer surface 2a of the short steel pipe 2 at predetermined intervals corresponding to the height of the S beams 3 so as to extend in the beam axis direction. A vertical portion 4a at one end of the mold has a high-strength bolt 5 inserted into each of the horizontal holes formed in the vertical portion 4a and the short steel pipe 2.
And it is joined to each outer side surface 2a of the short steel pipe 2 by a nut screwed to this. Between the overhanging end portions 4b formed of horizontal flanges on the other end side of the upper and lower beam joining members 4, S
The joining ends 32a of the upper and lower flanges 32 provided at both ends of the web 31 of the beam 3 are inserted and clamped, and inserted through the respective joining ends 32a and the respective vertical holes provided at the overhanging end 4b. The high-strength bolt 6 and a nut screwed thereto are fastened and joined to each other.

In this case, the joining between the short steel pipe 2 and the beam joining member 4 is performed by tensile joining using high-strength bolts 5.
The S beam 3 is friction-joined with the high-strength bolt 6. It is preferable to use high-strength high-strength bolts in order to minimize the number of high-strength bolts 5 and 6 used at each joint.

Further, in such a force transmission mechanism at the joint portion of the column and beam, a large tensile force acts on the beam joint member 4 and the force is transmitted to the outer surface of the short steel pipe 2.
Since there is a concern that the outer surface of the short steel pipe 2 may be locally deformed, it is preferable to use a relatively thick steel material as the short steel pipe 2 based on, for example, the yield line theory.

In the above embodiment, it is necessary to previously open a bolt hole for joining the beam joining member 4 to the short steel pipe 2, but no other processing is required. For this reason, although the weight of the steel material is slightly increased, the processing cost can be significantly reduced, and the short steel pipe 2 can be used as a form during concrete casting. As a result, it is possible to reduce the temporary cost associated with the concrete casting.

FIG. 3 shows the arrangement of reinforcing bars in the short steel pipe 2. In the case of the RC column 1, a hoop bar 1B that restrains a main bar 1A that secures reinforcement against shearing force and deformability as a member
However, since the short steel pipe 2 itself has the same effect as the hoop reinforcement by enclosing the short steel pipe 2 in the beam connection part of the RC column 1, the beam connection part as in the prior art is provided. It becomes possible to reduce the installation of the hoop muscle 1B in the inside.
As a result, it is possible to reduce the temporary construction cost due to the concrete casting and to improve the filling property of the concrete into the short steel pipe 2. In addition, since the head 5a of the high-strength bolt 5 protrudes from the inner surface of the short steel pipe 2, the head 5a is used as a shear key for transmitting a vertical load (force). The vertical load on the cast concrete (RC column 1) is transmitted to enhance the effect of supporting the S beam 3 and the short steel pipe 2. Moreover, the web 31 of the S beam 3
There is no need to open a hoop through-hole for inserting a hoop streak into the hole, and the processing cost can be reduced.

Further, it is necessary to secure a sufficient strength to join the beam joining member 4 to the short steel pipe 2. For this reason, according to the present invention, as shown in FIGS.
Is set to a range in which the lower limit is 1.1 times and the upper limit is 3.0 times the height H of the S beam 3. In this case, if the length L of the short steel pipe 2 is 1.1 times or less the height (beam height) H of the S beam 3, it is not possible to sufficiently secure the strength against the beam joining member 4 structurally mechanically. On the other hand, as long as the length L of the short steel pipe 2 is as long as possible, it is more advantageous to secure the proof stress.
When the height H of the S beam 3 is set to three times or more, the extension member 4
It has been found through experiments and analysis that improvement in proof stress cannot be expected.

FIGS. 6 and 7 show a second embodiment according to the present invention. In the second embodiment, in the first embodiment described above, a steel reinforcement in which a joining flange is integrally fixed in the short steel pipe 2 so as to extend vertically at each of the cross-shaped cross-section tips. The joining flanges of the member 7 are disposed on the inner surface of the short steel pipe 2 at the same level so as to face the beam joining member 4 that is in contact with the outer surface of the short steel pipe 2, A steel reinforcing member 7 is disposed between the inner facing surfaces of the short steel pipes 2 corresponding to the respective beam connecting members 4, and a lateral hole of the connecting beam member 4, a lateral hole of the short steel pipe 2, and the structural reinforcement By strongly connecting the high-strength bolt 5 and the nut that is screwed to the high-strength bolt 5 that is inserted across the horizontal hole of the joining flange 7b in the member 7,
It has a reinforcing structure formed by bridging the steel reinforcing member 7.
In this case, the width direction of the steel sheet forming the reinforcing member 7 is arranged in the vertical direction so as not to impair the filling property of the concrete. Each end 7a of the reinforcing member 7 having the joining flange 7b has a substantially T-shaped form, and is inserted into the through hole of the joining flange together with the joining of the beam joining members 4 as described above. And joined by a high-strength bolt 5. This prevents cross section deformation of the short steel pipe 2 due to a large force to be transmitted from the S beam 3.

FIG. 8 shows a third embodiment according to the present invention. In the third embodiment, a joining flange 7b is vertically welded to each tip of a horizontal steel plate cut and formed into a cross-shaped flat plate as the reinforcing member 7 in the second embodiment. It has a structure provided integrally. In this case, if the steel plate forming the reinforcing member 7 is wide, there is a possibility that the filling property of concrete may be impaired. Therefore, it is desirable to form the cross-shaped flat plate shape as narrow as possible.

In each of the above embodiments, a rectangular steel pipe has been described as the short steel pipe 2 for beam connection.
The present invention is not limited to this, and as shown in FIGS. 9 and 10 as a fourth embodiment according to the present invention, the present invention can be applied to a circular short steel pipe 2, and the selection is arbitrary.

In practicing the present invention, a one-side bolt may be used as the high-strength bolt 5.
In addition, when implementing the present invention, after arranging the column rebar,
A RC column form is disposed outside the column form, a short steel pipe 2 is placed on the column form, and an S beam 3 is appropriately supported by a supporting material. It can be built by placing concrete in the formwork.
In addition, RC columns with short steel pipes 2 can be built in advance, and floor slabs can be erected or built as appropriate.

In practicing the present invention, the joint between the short steel pipe 2 and the beam splicing member 4 or the joint between the beam splicing member 4 and the S beam 3 does not necessarily need to be bolt joining, and joining by welding is adopted. However, from the viewpoint of reducing the processing cost and improving the structural reliability, it is better to employ bolt joining rather than welding. In this way, when bolt joining is adopted, the welded portions of the members or the welded portions of the members are welded. Can be reduced as much as possible, and a portion serving as a starting point of destruction due to a welding defect can be eliminated. In addition, it goes without saying that the present invention can be variously modified and implemented without departing from the gist of the present invention.

[0028]

As described above, according to the joint structure of the reinforced concrete column and the steel beam according to the present invention, the inside of the beam joint portion of the reinforced concrete column member is included in the relatively thick short steel pipe, Since the beam joint member, where the steel beam member is joined to the outer peripheral side of the short steel pipe, is joined, the short steel pipe can be used as a formwork, and the factors that hinder the concrete filling property as before are surely confirmed. Can be eliminated.

Further, the joining between the short steel pipe, the beam joint member, and the steel beam member is made by a non-welding joining structure using high-strength bolts, thereby minimizing a welding portion. It is possible to eliminate a defective portion that is a starting point of the destruction, to reduce the processing cost and to improve the structural reliability.

Further, by setting the length of the short steel pipe within a range of 1.1 to 3.0 times the height of the steel beam member, it is possible to improve the strength of the beam joint.

Further, a reinforcing member having a cross shape is bridged and reinforced by non-welding with a high-strength bolt at a portion corresponding to the beam joining member in the short steel pipe, so that the beam should be transmitted from the steel beam member. The section deformation of the short steel pipe against a large force can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal side view showing a first embodiment of a joint structure between a reinforced concrete column and a steel beam according to the present invention.

FIG. 2 is a cross-sectional plan view of FIG.

FIG. 3 is an explanatory diagram showing a bar arrangement state in FIG. 1;

FIG. 4 is an explanatory diagram showing a lower limit setting range of a short steel pipe length with respect to a height of an S beam.

FIG. 5 is an explanatory diagram showing an upper limit setting range with respect to the height of an S beam of a short steel pipe length.

FIG. 6 is a partially longitudinal side view showing a second embodiment of the joint structure between a reinforced concrete column and a steel beam according to the present invention.

FIG. 7 is a cross-sectional plan view of FIG. 6;

FIG. 8 is a cross-sectional plan view showing a third embodiment of the joint structure between a reinforced concrete column and a steel beam according to the present invention.

FIG. 9 is a partially longitudinal side view showing a fourth embodiment of the joint structure between a reinforced concrete column and a steel beam according to the present invention.

FIG. 10 is a cross-sectional plan view showing a fourth embodiment of the joint structure between a reinforced concrete column and a steel beam according to the present invention.

FIG. 11 is an explanatory view showing a conventional column-beam joint structure.

FIG. 12 is an explanatory view showing another example of a conventional beam-column joint structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 RC column 1a Outer side surface 1A Main bar 1B Hoop bar 2 Short steel pipe for beam connection 2a Outer side surface 3 S beam 31 Web 32 Flange 32a Joining end surface 4 Beam joining member 4a Vertical portion 4b Other end side extension end portion 5 High strength bolt 5a Head 6 High strength bolt 7 Reinforcement member 7a End 7b Flange for joining L Length of short steel pipe H Height of S beam

Claims (6)

[Claims] An outer peripheral side of a beam joining portion of a reinforced concrete column member is wrapped around a relatively thick short steel pipe for beam joining, and a beam joining member is joined to the short steel pipe, and a steel frame is attached to the beam joining member. A joint structure between a reinforced concrete column and a steel beam, characterized by joining beam members. 2. The joint structure between a reinforced concrete column and a steel beam according to claim 1, wherein the beam joining member has a form such as a split tee or an angle. 3. The short steel pipe and the beam joint member, and the joint portion between the beam joint member and the steel beam member are joined by non-welding with high-strength bolts. Or a joint structure between the reinforced concrete column and the steel beam according to any one of 2. 4. The length of the short steel pipe is set within a range of 1.1 to 3.0 times the height of the steel beam member. 3. A joint structure between the reinforced concrete column and the steel beam according to any one of 3. 5. The beam joining member according to claim 1, wherein said beam connecting member in said short steel pipe is cross-linked and joined to a corresponding portion by non-welding with a high-strength bolt. A joint structure between the reinforced concrete column and the steel beam according to any one of the above. 6. The joint structure between a reinforced concrete column and a steel beam according to claim 5, wherein the reinforcing member has a cross shape.