JP2013133620A - Junction structure of concrete column and steel frame beam, and joint method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ensured stress transmission at a junction of a concrete column and a steel frame beam, where the steel beam penetrates through the concrete column or an end of the steel beam is embedded in a concrete column, and an ensured horizontal strength of the whole frame including the junction.SOLUTION: A junction structure 10 of an RC column and an S beam, where the S beam 14 penetrates through the RC column 12 and one end of the S beam 16 is embedded in the RC column 12, allows the RC column 12 to be prestressed due to tension applied to a PC steel 20 which is inserted in the PC column 12.

Description

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

  A building structure having a mixed structure in which a concrete column such as a reinforced concrete column or a steel reinforced concrete column and a steel beam are combined is known (for example, see Patent Documents 1 and 2). Patent Documents 1 and 2 disclose a structure of a joint portion between a concrete column and a steel beam in which the steel beam penetrates the concrete column or the end of the steel beam is embedded in the concrete column.

Japanese Patent Laid-Open No. 7-180215 Japanese Patent Laid-Open No. 11-100900

  In the joint portion between the concrete column and the steel beam described in Patent Literatures 1 and 2, stress is transmitted between the concrete column and the steel beam by the support pressure between the concrete column and the steel beam. Here, in the case of a high-rise building, a tensile axial force is generated in the concrete column due to the horizontal force at the time of the earthquake, but if the bearing pressure between the concrete column and the steel beam is reduced by this tensile axial force, Stress is not sufficiently transmitted to the steel beam, the load of shearing force and bending moment by the steel beam is reduced, and the horizontal strength of the entire frame is reduced.

  The present invention has been made in view of the above circumstances, in which the steel beam penetrates the concrete column or the end of the steel beam is embedded in the concrete column and the stress at the joint between the steel column and the steel beam is obtained. It is an object to ensure the transmissibility and ensure the horizontal strength of the entire frame including the joint.

  In order to solve the above problems, a concrete column and a steel beam joint structure according to the present invention, wherein the steel beam penetrates the concrete column, or the end of the steel beam is embedded in the concrete column. And a steel beam are inserted into the concrete column so as to straddle the steel beam at least above and below the steel beam, and the PC steel material is tensioned to give a prestressing force to the concrete column. It is characterized by being.

  In the joint structure between the concrete column and the steel beam, the prestress force may be set to be greater than a tensile axial force generated in the concrete column during an earthquake.

  The method for joining a concrete column and a steel beam according to the present invention is a method of joining a concrete column and a steel beam so that the steel beam penetrates the concrete column or the end of the steel beam is embedded in the concrete column. The PC steel material is inserted through the concrete column so as to straddle the steel beam at least above and below, and the PC steel material is tensioned to give a prestress force to the concrete column.

  According to the present invention, the steel beam penetrates the concrete column, or the end of the steel beam ensures the transferability of stress at the joint between the concrete column and the steel beam embedded in the concrete column, and the joint The horizontal strength of the entire frame including

It is a perspective view which shows the column beam junction part structure which concerns on one Embodiment. It is a plane sectional view showing a column beam junction. FIG. 3 is a view (elevated view) taken along arrow 3-3 in FIG. 2. FIG. 4 is a sectional view (standing sectional view) taken along the line 4-4 in FIG. It is an elevational sectional view showing a procedure for constructing a column beam joint. It is an elevational sectional view showing a procedure for constructing a column beam joint. It is an elevational sectional view showing a procedure for constructing a column beam joint. It is a figure which shows the bearing effect between RC pillar and the embedding part of S beam. It is a bending moment diagram at the time of a horizontal force acting on RC pillar. It is a disassembled perspective view which shows the column beam junction part structure which concerns on other embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a column beam joint structure 10 according to an embodiment. As shown in this figure, the column beam joint structure 10 includes an RC column 12 which is a reinforced concrete column disposed on the outer periphery of a high-rise building, and an S beam which is a steel beam penetrating the RC column 12. 14, an S beam 16 that is orthogonal to the S beam 14 and has an end embedded in the RC column 12, and a cover plate 18 that surrounds the joint between the RC column 12 and the S beams 14 and 16.

  The intermediate portion of the S beam 14 and the end portion of the S beam 16 are welded, and these joint portions are formed in a G shape (T shape) in plan view, and are embedded in the RC column 12. Further, the cover plate 18 is configured to have a rectangular cross-sectional shape by a pair of steel plates 18A having a L-shaped flat cross-sectional shape and a steel plate 18B having a U-shaped flat cross-sectional shape. The steel plate 18 </ b> A is disposed at a corner portion composed of the S beam 14 and the S beam 16 and is welded to the web 14 </ b> A of the S beam 14 and the web 16 </ b> A of the S beam 16. The steel plate 18B is disposed on the opposite side of the steel plate 18A with the S beam 14 interposed therebetween, and is welded to the web 14A of the S beam 14.

  The inner side surfaces of the steel plates 18A and 18B are arranged so as to be flush with the side surfaces of the RC pillar 12, and the concrete is filled in the space surrounded by the steel plates 18A and 18B and the S beams 14 and 16, A joint portion 11 made of square steel pipe concrete is formed.

  The RC pillar 12 has a plurality of PC steel materials 20 built therein. Each PC steel material 20 is provided corresponding to each of the four corners of the PC pillar 12, and is arranged so as to extend over a plurality of floors. The PC steel material 20 includes a PC steel rod, a PC steel wire, and the like.

  2 is a cross-sectional plan view showing the beam-column joint 10, FIG. 3 is a sectional view (elevated view) taken along the line 3-3 in FIG. 2, and FIG. (Elevated sectional view). It should be noted that the main bars and the band bars of the RC column 12 are not shown.

  As shown in FIGS. 2 to 4, each PC steel material 20 is inserted between the cover plate 18 and the S beams 14 and 16 in the joint portion 11, and the upper end protrudes from the joint portion 11 on the predetermined floor. The upper and lower PC steel materials 20 are connected by a coupler 22 on the upper side of the joint portion 11 on a predetermined floor. Further, the plurality of PC steel materials 20 are tensioned, and a pre-stress force that is a compression axial force is introduced into the RC column 12. Here, the prestressing force, which is the compression axial force introduced into the RC column 12, is set to be equal to or greater than the tensile axial force acting on the RC column 12 during an earthquake, and the compression axial force is applied to the RC column 12 even during an earthquake. Works.

  5 to 7 are elevation sectional views showing a procedure for constructing the column beam joint 10. First, as shown in FIG. 5, an RC column body 12A, which is a precast product in which a sheath tube 24 for inserting a PC steel material 20 is embedded, is built, and S beams 14 and 16 and a cover plate welded thereon. 18 is installed. Then, a sheath tube 26 and a reinforcing bar for inserting the PC steel material 20 are installed between the blocking plate 18 and the S beams 14 and 16, and concrete is filled between the blocking plate 18 and the S beams 14 and 16. The joint part 11 is constructed. Then, RC pillar body 12A is installed on the joint part 11, and grout is inject | poured into the joint of the joint part 11 and RC pillar body 12A, or the joint of a reinforcing bar.

  Then, as shown in FIG. 6, when the building of the RC pillar 12 and the S beams 14, 16 for one layer (a plurality of floors) is completed, the PC steel material 20 is inserted into the sheath tubes 24, 26. Here, the upper end of the lower layer PC steel material 20 is projected from the lowermost joint portion 11 of the lower layer, and a coupler 22 is attached to the upper end. Then, the lower end of the upper PC steel material 20 and the upper end of the lower PC steel material 20 are connected by a coupler 22.

  Then, the upper end of the PC steel material 20 protruding from the uppermost joint portion 11 of the upper layer is connected to the hydraulic jack 28, and the PC steel material 20 is connected to the joint portion in a state where tension is applied to the PC steel material 20 with the hydraulic jack 28. 11 is fixed to the upper part. As a result, the PC steel material 20 is tensioned and a prestressing force that is a compression axial force is introduced into the upper RC column 12.

  Then, as shown in FIG. 7, the grout is filled into the sheath tubes 24 and 26 from the grout inlet 30 provided in the RC column 12. As described above, the RC pillars 12 and the S beams 14 and 16 for a plurality of floors are built, and a prestress force that is a compression axial force is introduced into the RC pillars 12 for a plurality of floors.

  FIG. 8 is a view showing a support pressure action between the RC column 12 and the embedded portion of the S beam 16, and FIG. 9 is a bending moment diagram when a horizontal force is applied to the RC column 12.

  As shown in FIG. 8, when the horizontal force Qr in the axial direction of the S beam 16 acts on the RC column 12 to which the compressive axial force Nr is applied, the upper and lower flanges 16B of the embedded portion of the S beam 16 and the upper and lower flanges 16B A support pressure P due to the lever action of the S beam 16 is generated between the RC column body 12 </ b> A, and stress transfer between the RC column 12 and the S beam 16 is performed by the support pressure P. At this time, as shown in FIG. 9, the RC column 12 and the S beam 16 have bending moments that are the maximum at both ends and the minimum at the center, respectively. Arise.

  That is, when the horizontal force Qr is applied to the RC column 12 in the state where the compression axial force Nr is applied, the stress transmission between the RC column 12 and the S beam 16 is performed well, and the S beam 16 is sheared and bent. Will bear the moment.

  Here, in a high-rise building, a tensile axial force may be generated in the column due to a horizontal force at the time of an earthquake, and a tensile shaft having a magnitude exceeding the compressive axial force on the RC column in which the end of the S beam is embedded and joined. When a force is generated, a support pressure P is not generated between the embedded portion of the S beam and the upper and lower RC columns, and stress transmission is not performed between the RC column and the S beam.

  In contrast, in the column beam joint structure 10 according to the present embodiment, a compressive axial force greater than the tensile axial force generated during an earthquake is prestressed on the RC columns 12 above and below the embedded portion of the S beam 16. By introducing the force, a support pressure P due to the lever action of the S beam 16 is generated between the upper and lower flanges 16B of the embedded portion of the S beam 16 and the upper and lower RC columns 12, and the RC column 12 and the S column Stress transmission to and from the beam 16 is favorably performed. As a result, when a horizontal force in the axial direction of the S beam 16 acts on the RC column 12 during an earthquake, the S beam 16 can be subjected to a shearing force and a bending moment, and the RC column 12 and the S beam 16 are included. It is possible to ensure horizontal proof stress in the axial direction of the S beam 16 of the frame.

  Similarly, when a horizontal force in the axial direction of the S beam 14 acts on the RC column 12, a bearing pressure is generated between the upper and lower flanges 14B of the embedded portion of the S beam 14 and the RC column 12, and the RC column. Stress transmission between the S 12 and the S beam 14 is performed well. As a result, when a horizontal force in the axial direction of the S beam 14 acts on the RC column 12 during an earthquake, the S beam 14 can be subjected to a shearing force and a bending moment, and the frame including the RC column 12 and the beam 14 can be loaded. The horizontal proof stress in the axial direction of the S beam 14 can be ensured.

  In addition, the above-mentioned embodiment is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof. For example, in the above-described embodiment, the present invention has been described by taking, as an example, the joint structure of a pair of S beams 14 and 16 joined in a T shape and the RC pillar 12 at the outer periphery of the building. The present invention is also applied to a joint structure between a pair of S beams joined to each other and an RC pillar as a corner pillar, a joint structure between a pair of S beams joined to a cross shape and an RC pillar on the inner peripheral side of the building, and the like. Can be applied.

  Moreover, in the above-mentioned embodiment, although the joint part 11 was constructed | assembled by hitting concrete on-site, as shown in FIG. 10, it is a precast structure by which S beams 114 and 116 and concrete were integrated previously. A certain joint 111 may be used. Further, as shown in the figure, the joint portion 117 of the S beams 114 and 116 is produced separately from the main body portions 114A and 114B of the S beams 114 and 116, and the joint portion 117 and the joint portion 111 are preliminarily formed. An integrated precast structure 119 may be manufactured, and the joint portion 117 and the S beams 114 and 116 may be joined on site.

  Moreover, in the above-mentioned embodiment, although the RC pillar 11 was mentioned as an example as a concrete pillar, other concrete pillars, such as a column made from a steel reinforced concrete, may be sufficient. Further, the concrete pillar may be made of precast concrete, or may be produced by placing concrete on site.

  Moreover, in the above-mentioned embodiment, the pre-stress force was introduced to the RC pillars 12 for a plurality of floors by tensioning the PC steel material 20 penetrating the RC pillars 12 for a plurality of floors. The prestressing force is introduced into the RC pillar 12 for each floor by tensing the PC steel material that penetrates the 12th floor, or the bottom floor by tensioning the PC steel material that penetrates the RC pillar 12 from the bottom floor to the top floor. A prestressing force may be introduced to the RC pillars 12 from the top to the top floor all at once.

  Moreover, what is necessary is just to set suitably the number and arrangement | positioning of the PC steel materials 20, and what is necessary is just to set the presence or absence and structure of the cover board 18 suitably. Moreover, the filling of the grout into the sheath tubes 24 and 26 is not limited to press-fitting from the bottom, but may be performed by pouring from the top.

  Furthermore, in the above-described embodiment, a sheath tube is driven into concrete, a PC steel material such as a PC steel rod or a PC steel wire is inserted therein, and the PC steel material is tensioned, and then the gap between the sheath tube and the PC steel material A method of filling a grout material such as mortar into the mortar was used. However, it is also possible to use a method (unbond method) in which a PC steel material covered with a cover such as vinyl is driven into concrete and covered only with a sheath tube or the like that moves when a coupler joint or the like is in tension, and the PC steel material is tensioned. .

10 beam-column joint structure, 11 joint, 12 RC column (concrete column), 14 S beam (steel beam), 14A web, 14B flange, 16 S beam (steel beam), 16A web, 16B flange, 18 cover Plate, 18A, 18B Steel plate, 20 PC steel, 22 Coupler, 24, 26 Sheath tube, 28 Hydraulic jack, 111 Joint, 114 S beam, 114 A body part, 116 S beam, 116 A body part, 117 joint part, 119 Precast structure

Claims (3)

The steel beam penetrates the concrete column, or the end part of the steel beam is a joint structure between the concrete column and the steel beam embedded in the concrete column,
A concrete column and a steel beam, wherein a PC steel material is inserted through the concrete column so as to straddle at least above and below the steel beam, and the PC steel material is tensioned to give a prestressing force to the concrete column. Joint structure.   The joint structure of a concrete column and a steel beam according to claim 1, wherein the prestress force is set to be equal to or greater than a tensile axial force generated in the concrete column during an earthquake. A method of joining a concrete column and a steel beam so that the steel beam penetrates the concrete column or the end of the steel beam is embedded in the concrete column,
A method for joining a concrete column and a steel beam, characterized in that a PC steel material is inserted into the concrete column so as to straddle the steel beam at least above and below the steel beam, and the PC steel material is tensioned to give a prestressing force to the concrete column. .

Images