JP2000257158A - Frame structure formed of flat slabs and steel pipe columns - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure of a joint portion between a column and a slab by building a brace member in a frame formed of flat slabs and steel pipe columns. SOLUTION: A frame is made up of an upper-story RC flat slab 1, a lower- story RC flat slab 3, and CFT columns 5, 7 which are set at a predetermined interval. Gusset plates 9, 11, are fixed to joint portions of the columns 5, 7 to the slab 3, and a brace mounting member 13 is fixed to the lower surface of the slab 1. Then, one end of each of the brace members 15, 17 is fixed to each of the gussets 9, 11, and the other end to the member 13. Next, the member 13 has one portion thereof embedded in the slab 1, and the embedded portion is provided with a shear connector. In place of this, a steel beam constituted of an H-shaped steel is erected between the columns 5, 7, which is then embedded in the slab 1, and the member 13 is installed on the slab 1, to thereby connect one end of the brace members 15, 17. Thus, the resisting ability to a horizontal force can be enhanced without providing a resisting element such as an RC earthquake resisting wall or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame structure of a building structure, and more particularly, to a flat slab and a steel pipe column (referred to as a steel pipe column in this specification, a so-called CFT column in which concrete is filled inside a steel pipe column. ).

[0002]

2. Description of the Related Art A flat slab structure is a construction method mainly used for reinforced concrete construction, and both slabs and columns are generally made of reinforced concrete construction. in this case,
At the joint between the column and the slab, a bearing portion called “capital” as shown in FIG. 14 is provided. like this,
If both the columns and slabs are made of reinforced concrete, the dimensions of the capital section are enlarged and the arrangement of the bars is made tight, so that the columns and the slabs are rigidly connected, and the frame is resistant to horizontal forces such as earthquakes. Can be done.

[0003] In recent years, so-called CFT columns having a structure in which a circular or square steel pipe is filled with concrete have been widely used. CFT columns have the feature of being able to support high axial forces. On the other hand, flat slab structures are also often used when the load on the floor is large. It can be said that combining slabs (hereinafter referred to as “RC flat slabs”) is a reasonable construction method.

[0004] In this case, how to join the CFT column and the RC flat slab is a problem, and as an invention relating to this point, for example, Japanese Patent Application Laid-Open No. H8-208 shown in FIGS.
There is a joint structure between a steel pipe concrete column and a flat slab disclosed in JP-A-10-96995. In the publication,
As shown in FIGS. 15 and 16, a supporting steel plate 52 and a rib 53 are welded to a steel pipe column 51 filled with concrete 54 to support the vertical load of a flat slab 55.

As another example, FIG.
There is an invention of a frame including an S column and an RC flat slab disclosed in JP-A-814418. In the gazette disclosed in the publication, steel receiving bodies 72 and 73 are fixed to a lower portion and an upper portion of a joining position of a flat slab 74 on an outer peripheral portion of an S column 71 by welding or the like, respectively. The upper surface of the receiving member 72 is brought into contact with the lower portion of the slab 74, the lower surface of the upper receiving member 73 is brought into contact with the upper portion of the slab 74, and the lower receiving member 72 and the upper The peripheral surface of the S pillar 71 between the receiving body 73 and the
The column 71 and the RC flat slab 74 are joined. The joint structures of the above two inventions can be regarded as pin joints.

[0006] Further, the joint between the column and the floor has a joint structure that can be regarded as a rigid joint.
There is an invention of a joint structure between a steel pipe column and a slab in a flat slab structure disclosed in JP-A-88392. The steel disclosed in the publication is such that a reinforcing steel bar 65d is joined to the intersection 61a of a steel pipe column 62 of a steel pipe 62a and a slab 63 and a slab 63 around the steel pipe 62a on both upper and lower sides in the longitudinal direction.
This is provided with a reinforcing iron plate 65 penetrating through 2a.

[0007]

Problems to be Solved by the Invention
No. 5 and Japanese Patent Application Laid-Open No. 6-81418 have a relatively simple structure, but have a low rigidity at the joint, and are regarded as a pin joint in design. Therefore, it is necessary to separately provide a resistance element against a horizontal force such as an earthquake. For example, it is necessary to take measures such as providing an RC shear wall as shown in FIG. In this case, there are problems such as restrictions on the plan of the plan, and complicated arrangement of reinforcing bars in order to ensure transmission of the horizontal force from the slab to the shear wall.

[0008] In Japanese Patent Application Laid-Open No. 6-88392, a relatively rigid joint can be obtained. However, there is a problem that the processing for realizing this is extremely complicated and the cost is high.

As described above, in the conventional frame structure including the flat slab and the steel pipe column, the structure itself at the joint between the CFT column and the RC flat slab is simple, but the resistance to the horizontal force is small, and the structure is separately provided in portions other than the frame. There is a problem that it is necessary to provide a resistance element and that the CFT column and the RC flat slab can be rigidly joined, but they are not practical in terms of processing and cost.

The present invention has been made in order to solve such a problem, and has a simple structure at the joint between the column and the slab, eliminating the need to separately provide a resistance element in a portion other than the frame, thereby reducing the cost as a whole. The purpose is to obtain a frame structure consisting of a flat slab and steel pipe columns.

[0011]

According to the present invention, there is provided a frame structure comprising a flat slab and a steel pipe column, wherein a brace material is incorporated in a frame composed of the flat slab and the steel pipe column.

Further, one end of the brace material is attached to the flat slab via a brace attachment member, and the brace attachment member is partially embedded in the flat slab, and a shear is attached to the embedded portion. It has a connector.

Further, a shaft member is provided between the adjacent steel pipe columns, and one end of the brace member is connected to the shaft member.

Further, the shaft member is embedded in the flat slab.

[0015] Further, at two positions of the slab lower surface and the slab upper surface of the steel tube column, there are provided pressure bearing plates joined so as to surround the steel tube column, and the pressure plate is capable of reducing a bending moment caused by a horizontal external force. It is characterized in that it projects to the slab side to the extent that it can be transmitted.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an explanatory view of an embodiment of the present invention. First, the overall configuration will be outlined based on FIG. In the drawing, 1 is an RC flat slab on the upper floor, 3 is an RC flat slab on the lower floor, 5, 7 are CFT columns installed at predetermined intervals, and 9 and 11 are CFT columns 5, 7 respectively. The gusset plate 13 is fixed to the joint of the lower flat RC slab 3 and the brace mounting member 13 installed on the lower surface of the upper flat RC slab 1.

Reference numerals 15 and 17 denote brace members having one end fixed to the gusset plates 9 and 11 and the other end fixed to the brace mounting member 13, respectively. Brace material 1
As the materials 5 and 17, the materials used for ordinary steel frame structures can be used. Also, the brace materials 15,1
7 and the brace attachment member 13 and the gusset plates 9 and 11 are joined by the same method as that of a normal steel frame structure, such as bolt joining and welding.

Next, a detailed configuration of each section will be described. FIG.
Is a front sectional view of a joint between the brace attachment member 13 and the RC flat slab 1, and FIG. 3 is a side sectional view. As shown in FIGS. 2 and 3, the mounting member 13 includes a gusset plate 13a, a fixing plate 13b, and a shear connector 13c including stud bolts, and these members are joined by welding. The fixing member 13 includes the fixing plate 1.
The vertical direction and the horizontal direction are integrated with the RC flat slab by the 3b and the shear connector 13c, respectively.

FIG. 4 is a sectional view of a portion A surrounded by a circle in FIG. In the figure, 21 is a supporting plate fixed to the CFT column 7, and 23 is a reinforcing plate installed inside the steel pipe for reinforcing against out-of-plane deformation of the steel pipe. The RC flat slab 3 is installed on the support plate 21.

According to the present embodiment configured as described above, when a horizontal force such as an earthquake acts, the brace material 1
Since 5, 17 will resist this horizontal force, RC
There is no need to strengthen the joint between the flat slab 3 and the CFT columns 5, 7, and as a result, a simple joint as shown in FIG. 4 becomes possible.

The horizontal force resistance of the frame is determined according to the joining method of the CFT column and the RC flat slab, and the performance of the members of the CFT column and the RC flat slab, and the necessary cross section and arrangement amount of the brace member are determined. Then, the brace attachment member 13 according to the burden axial force of the brace material at this time.
Therefore, an efficient and economical frame structure can be realized.

Embodiment 2 FIG. FIG. 5 shows the brace attachment member 31 and the RC flat slab 1 according to the second embodiment.
FIG. 6 is a side cross-sectional view of a joint portion with the above. In the present embodiment, the brace attaching member 31 is
Gusset plate 31a and gusset plate 31a
Is formed by a shear connector 31c fixed at a right angle to the surface. In this example, the brace mounting member 3
1, the vertical and horizontal directions are integrated with the flat slab 1 by the shear connector 31c. The brace attaching member 31 of the present embodiment is relatively light (has a small horizontal resistance) as compared with the first embodiment.
Selected when using braces.

According to the present embodiment, the structure of the brace attachment member 31 is simpler than that of the first embodiment and the number of parts is reduced, so that the manufacturing cost can be reduced.

Embodiment 3 FIG. FIG. 7 is an explanatory view of Embodiment 3 of the present invention, in which the RC flat slab is omitted. In the third embodiment, adjacent CFTs
A steel beam 35 having an H-shaped cross section is provided between the columns 5 and 7, and the brace attachment member 13 is joined to the steel beam 35.

Since the brace mounting member 13 is joined to the lower surface of the steel beam 35, it is composed of only a gusset plate. FIG. 8 is an enlarged sectional view of a portion B surrounded by a circle in FIG. (However, FIG. 8 shows the RC flat slab 1 omitted in FIG. 7.) As shown in FIG. 8, the steel beam 35 has a rib plate 36 joined to the CFT column 7.
Are joined by high-strength bolts via a joining plate 37. Since this joint only needs to transmit the axial force of the steel beam 35 (it is not necessary to transmit the bending moment), a necessary and sufficient joint is constituted by a small bolt joint 8 like a normal pin joint. can do.

Further, since the steel beam 35 only needs to resist the axial force, the cross section may be relatively small. Therefore,
As shown in FIG. 8, the entire steel beam 35 can be accommodated inside the RC flat slab 1. By doing so, the periphery of the steel beam 35 is restrained by the RC flat slab 1, so there is no need to separately provide reinforcement for buckling. Further, in this case, the horizontal force transmission ability is further improved as compared with the first and second embodiments. In the above example, the rib plate 36 is provided separately. However, if there is a rib plate provided for joining the CFT column 7 and the RC flat slab 1, the rib plate 36 can be used.

Embodiment 4 FIG. 9 is an explanatory view of Embodiment 4 of the present invention, and shows a cross section of a joint between a CFT column and an RC flat slab. In the present embodiment, C
At the joint between the FT column 7 and the RC flat slab 1,
The lower support plate 41 and the upper support plate 43 are provided, and the RC flat slab 1 is sandwiched between them from above and below.

As described above, the RC flat slab 1 is
The bending moment can be transmitted from the RC flat slab 1 to the CFT column 7 by sandwiching the upper and lower supporting plates 41 and 43 fixed to the T column 7.

Hereinafter, the bending moment transmitting mechanism according to the present embodiment configured as described above will be described with reference to FIGS. With respect to the reverse symmetric bending moment generated when receiving a horizontal force as shown in FIG.
In the RC flat slab 1, as shown in FIG. 10, stresses of a tensile force T1 and a compressive force C1 (and T2, C2) are generated at column ends. Some of these forces, as shown in FIG. 11, combine the left-hand tensile force T1 with the right-hand compressive force C2 to act on the right side of the column as C12, and similarly the right-hand tensile force T2.
2 acts on the left side of the column as C11 in combination with the compression force C1 on the left side.

Further, in the present embodiment, since the upper and lower support plates 41 and 43 for supporting the RC flat slab 1 are larger than the CFT columns 7, it is possible to transmit the stress by the mechanism as shown in FIG. That is, the slab ends have shear forces Q1 and Q2 in accordance with the bending moment, and when the forces push the upper and lower support plates 41 and 43, compressive forces C21 and C22 are generated. Since these forces act on the CFT column 7 as a couple (bending moment) having a long arm length, the bending moment at the slab end is reduced by the CFT column 7.
Is reliably transmitted.

Further, since the upper and lower support plates 41 and 43 are installed so as to surround the CFT column 7, as shown in FIG.
A couple that twists the T-column 7 from the side surface becomes a couple, and a couple due to a shearing force such as Qs (generated on the upper and lower supporting plates) transmits the slab bending moment to the column side.

A large bending moment can be transmitted from the RC flat slab 1 to the CFT column 7 by overlapping the above operations. As described above, according to the present embodiment, the horizontal force can be effectively transmitted to the CFT columns in combination with the effects of the brace members 15 and 17.

[0033]

As described above, the present invention has the following advantages.

By incorporating a brace material into a frame composed of flat slabs and steel pipe columns, it is possible to realize a frame structure having a high level of resistance to horizontal force without separately providing a resistance element such as an RC shear wall. it can.

One end of the brace material is attached to the flat slab via a brace attachment member, and the brace attachment member is partially embedded in the flat slab, and a shear connector is attached to the embedded portion. With this configuration, the brace member and the flat slab are integrated, the joining of the brace member and the flat slab becomes strong, and the brace member can function effectively against horizontal force.

Further, a shaft member is erected between adjacent steel pipe columns,
Since one end of the brace member is connected to the shaft member, a horizontal force resistance mechanism similar to a normal steel frame brace frame is formed, and the horizontal force transmission capability is further improved.

Further, since the shaft member is embedded in the flat slab, the periphery of the shaft member is restrained by the flat slab, so that it is not necessary to separately provide reinforcement for buckling.

Further, a pressure plate is provided at two positions on the lower surface of the slab and on the upper surface of the slab of the steel pipe column, the pressure plate being joined so as to surround the steel pipe column, and the pressure plate is capable of reducing a bending moment caused by a horizontal external force. By adopting a configuration that projects to the slab side to the extent that it can be transmitted, the horizontal force can be effectively transmitted to the steel pipe column in combination with the effect of the brace material.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an overall configuration of a first embodiment of the present invention.

FIG. 2 is a front sectional view of a joint between the brace attachment member 13 and the RC flat slab 1 according to Embodiment 1 of the present invention.

FIG. 3 is a side sectional view of a joint between the brace attachment member 13 and the RC flat slab 1 according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a portion A surrounded by a circle in FIG.

FIG. 5 is a front sectional view of a joint between the brace attachment member 31 and the RC flat slab 1 according to the second embodiment.

FIG. 6 is a side sectional view of a joint between the brace attachment member 31 and the RC flat slab 1 according to the second embodiment.

FIG. 7 is an explanatory diagram of Embodiment 3 of the present invention.

8 is an enlarged sectional view of a portion B surrounded by a circle in FIG. 7; (However, FIG. 8 shows the RC flat slab 1 omitted in FIG. 7)

FIG. 9 is an explanatory diagram of Embodiment 4 of the present invention.

FIG. 10 is an explanatory diagram of a bending moment transmission mechanism according to a fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram of a bending moment transmission mechanism according to Embodiment 4 of the present invention.

FIG. 12 is an explanatory diagram of a bending moment transmission mechanism according to a fourth embodiment of the present invention.

FIG. 13 is an explanatory diagram of a bending moment transmission mechanism according to Embodiment 4 of the present invention.

FIG. 14 is an explanatory view of a conventional joint portion between a pillar and a slab.

FIG. 15 is an explanatory view of a conventional joint structure between a steel pipe concrete column and a flat slab.

FIG. 16 is an explanatory view of a conventional joint structure between a steel pipe concrete column and a flat slab.

FIG. 17 is an explanatory diagram of a frame including a conventional S pillar and an RC flat slab.

FIG. 18 is an explanatory view of a joint structure between a steel pipe column and a slab in a conventional flat slab structure.

FIG. 19 is a diagram showing an example of an RC shear wall as a resistance element against horizontal force in a conventional example.

[Explanation of symbols]

 1,3 RC flat slab 5,7 CFT column 13 Brace mounting member 13c Shear connector 15,17 Brace material 31 Brace mounting member 31c Shear connector 35 Steel beam 41 Lower support plate 43 Upper support plate

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuhisa Imamoto 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. F-term (reference) 2E125 AA04 AA33 AA57 AB16 AB17 AC01 AC16 AE04 AG03 AG04 AG45 AG57 BA02 BA33 BB01 BB12 BB28 BD01 BE07 BE08 CA05

Claims (5)

[Claims] 1. A frame structure comprising a flat slab and a steel pipe column, wherein a brace material is incorporated into a frame composed of a flat slab and a steel pipe column. 2. An end of the brace material is attached to the flat slab via a brace attachment member, and the brace attachment member is partially embedded in the flat slab, and a shear is applied to the embedded portion. The frame structure comprising a flat slab and a steel pipe column according to claim 1, further comprising a connector. 3. A shaft member is erected between the adjacent steel pipe columns,
2. A frame structure comprising a flat slab and a steel pipe column according to claim 1, wherein one end of said brace material is connected to said shaft member. 4. A frame structure comprising a flat slab and a steel pipe column according to claim 3, wherein said shaft member is embedded in said flat slab. 5. A supporting plate joined so as to surround the steel pipe column at two positions of a lower surface position of the slab and an upper surface position of the slab in the steel tube column, wherein the supporting plate reduces a bending moment caused by a horizontal external force. The frame structure comprising a flat slab and a steel pipe column according to any one of claims 1 to 4, wherein the frame structure extends to the slab side to such an extent that transmission is possible.