JP2010285780A - Column-beam joint structure and building having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the workability of a cross section reducing part. <P>SOLUTION: A column-beam joint structure 13 includes joint plates 20, 21 for jointing a flange plate 18A of a bracket 18 with a flange plate 14A of a beam member 14. These joint plates 20, 21 are respectively formed with notches 26, 28. Cross section reducing parts 20A, 21A are respectively provided whose sectional areas are made smaller than the other parts of the joint plates 20, 21 by the notches 26, 28. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a column beam connection structure and a building having a column beam connection structure.

  In the Hyogoken-Nanbu Earthquake, etc., many damages with fractures were found in the steel beam-to-column joints, and further improvements in the beam-column joint structure were required. As an improvement measure, an RBS (Reduced Beam Section) method is proposed in which the bending strength of the beam is partially reduced and a plastic hinge is generated at a position away from the beam-column joint (for example, Patent Document 1, Patent) Reference 2).

  In Patent Document 1, a notch is formed in a flange plate of an H-shaped beam in a column beam joining structure of a box column (column) and an H-shaped beam (beam). This notch is formed at a position away from the box column. The bending strength of the H-shaped beam is reduced by this notch, and a plastic hinge (plasticization) is generated at a portion where the notch is formed before the column beam joint. Thereby, the fracture | rupture and damage of a column beam junction part are suppressed.

  Moreover, in patent document 2, the notch is provided in the flange plate of the beam which consists of H-shaped steel. This notch is formed at a position away from the pillar. Further, a steel plate made of low yield point steel having the same thickness as that of the flange plate is fitted into the notch and welded. The flange plate of the beam is reinforced by a steel plate made of this low yield point steel.

  In Patent Documents 1 and 2, a notch is formed in the flange plate of the beam. However, since a beam generally has a long span and is inconvenient to handle, it takes time to form a notch in the flange plate. Further, the frictional heat at the time of forming the notch may cause a dimensional error in the beam, or the physical properties of the steel material may change and cause a problem in the strength of the beam.

  On the other hand, in Patent Document 3, a bracket welded to a column and a steel beam member are joined by a splice plate. The splice plate is made of low yield point steel. Thereby, the yield load of the splice plate is relatively reduced, and the plastic hinge is generated in the splice plate before the column, the bracket, and the welded portion.

  However, since the yield load of the splice plate depends on the mechanical properties of the low yield point steel, its adjustment range is small and the design flexibility is lacking.

JP-A-8-4112 JP 2001-49740 A JP 10-317490 A

  In view of the above fact, an object of the present invention is to improve the workability of the cross-sectionally reduced portion.

  The beam-column joint structure according to claim 1 is a steel bracket projecting from a column, a steel beam member joined to the steel bracket, a first flange plate of the steel bracket, and a second flange of the steel beam member. A steel joining plate overlaid on the plate, a cross-sectionally reduced portion provided on the joining plate and having a smaller sectional area than other portions of the joining plate, the first flange plate and the second flange plate And a joining means for joining the joining plate.

  According to said structure, a beam is comprised by joining a steel frame bracket and a steel beam member via a joining plate. The joining plate is superposed on the first flange plate of the steel frame bracket and the second flange plate of the steel beam member, and is joined to each of the first flange plate and the second flange plate by the joining means. Further, the joint plate is provided with a cross-sectional reduced portion having a smaller cross-sectional area than other portions of the joint plate, and the bending strength of the beam is partially reduced by the cross-sectional reduced portion.

  Here, by providing a cross-section reduced part in the joint plate and partially reducing the bending strength of the beam, the beam where the cross-section reduced part of the joint plate is located before the joint between the column and the steel bracket during an earthquake. A plastic hinge can be generated at the site (hereinafter, the beam site where the cross-sectionally reduced portion of the joining plate is located, and the site where the plastic hinge occurs is referred to as a plastic hinge). Therefore, a bending moment greater than the bending strength of the plastic hinge portion does not act on the joint between the column and the steel bracket. Therefore, compared with the case where a plastic hinge part is not provided, the bending moment which acts on the junction part of a pillar and a steel bracket is reduced, and the fracture | rupture, damage, etc. of the said junction part can be suppressed.

  In addition, since the cross-section reduced portion is provided in the joining plate, the cross-section reduced portion can be easily processed, so that the manufacturing cost can be reduced. Further, by concentrating the plastic deformation on the cross-section reduced portion, it is possible to concentrate the damage and damage of the beam during the earthquake on the joining plate. For this reason, the beam can be repaired by exchanging the damaged or damaged joining plate.

  Furthermore, the joint plate can be applied to general bracket-type beam-column joints, so it is highly versatile, and the bending strength of the plastic hinge part of the beam can be increased or decreased by increasing or decreasing the cross-sectional area of the reduced-section part. Can be adjusted.

  The beam-column joint structure according to claim 2 is the beam-column joint structure according to claim 1, wherein the joining means is a plurality of holes penetrating the joint plate and the first flange plate or the second flange plate. A high-strength bolt and a nut attached to the high-strength bolt, and an elastic body is sandwiched between the high-strength bolt or the nut and the joining plate.

  According to the above configuration, the joining means includes a joining plate and a plurality of high-strength bolts penetrating the first flange plate or the second flange plate, and nuts attached to the high-strength bolts. The joining plate and the first flange plate or the second flange plate are frictionally joined by the high-strength bolts and nuts. An elastic body is sandwiched between the high-strength bolt or nut and the joining plate.

  Here, when the cross-section reduced portion of the joining plate is plasticized, the thickness of the cross-section reducing portion and its peripheral portion is reduced due to the elongation deformation of the joining plate, and between the joining plate and the first flange plate and the second flange plate. There may be a gap. When this gap occurs, the introduction axial force of the high-strength bolt that acts between the joining plate and the first flange plate or the second flange plate decreases. Accordingly, the friction joint strength by the high-strength bolts and nuts is lowered, and the transmission efficiency of the bending moment is lowered.

  As a countermeasure, in the present invention, an elastic body is provided between the high-strength bolt or nut and the joining plate. Thereby, even if the plate | board thickness of a cross-section reduction | decrease part and its peripheral part reduces, the clearance gap between a joining plate, a 1st flange plate, and a 2nd flange plate is suppressed by the restoring force of an elastic body. Therefore, the reduction of the introduced axial force due to the high-strength bolt is suppressed, the friction joint strength can be ensured, and the decrease in the bending moment transmission efficiency can be reduced.

  Further, the reduction rate of the thickness of the joining plate due to plasticization increases as the cross-section reduction portion is approached. Therefore, by providing an elastic body between the high-strength bolt or nut in the row closest to the cross-sectionally reduced portion and the joining plate, the gap between the joining plate, the first flange plate, and the second flange plate can be efficiently suppressed. it can.

  The column beam connection structure according to claim 3 is the column beam connection structure according to claim 2, wherein the elastic body is a disc spring.

  According to said structure, the elastic body is made into the disc spring. The disc spring can obtain a large restoring force with a small amount of deflection compared to a general spring washer or the like. Accordingly, the gap between the first flange plate or the second flange plate and the joining plate can be more reliably suppressed, and the reduction of the introduced axial force due to the high-strength bolt can be suppressed. Therefore, the friction bonding strength can be maintained, and a decrease in bending moment transmission efficiency can be more reliably suppressed.

  The beam-column joint structure according to claim 4 is the beam-column joint structure according to any one of claims 1 to 3, wherein the cross-section reducing portion is formed between the first flange plate and the second flange plate. It is provided in between.

  According to said structure, the cross-sectional reduction part formed in the joining plate is provided (positioned) between the 1st flange plate and the 2nd flange plate (gap). That is, the plastic hinge portion of the beam is located between the first flange plate and the second flange plate (gap).

  Here, the bending moment acting on the beam is transmitted from the first flange plate to the joining plate as an axial force via the joining means. In this case, in the part where the first flange plate and the joining plate overlap, the first flange plate and the joining plate bear the axial force, but only the joining plate exerts the axial force between the first flange plate and the second flange plate. Will bear. Therefore, by providing the cross-sectionally reduced portion between the first flange plate and the second flange plate, it is possible to apply all of the axial force due to the bending moment of the beam to the cross-sectionally reduced portion. Thereby, plasticization can be concentrated on the cross-sectionally reduced portion, and the plastic hinge can be more reliably generated in the plastic hinge portion of the beam where the cross-sectionally reduced portion is located.

  The building of Claim 5 has the said steel frame bracket and the said steel beam member joined by the column beam joining structure of any one of Claims 1-4.

  According to said structure, the building has the steel frame bracket and steel beam member joined by the column beam joining structure of any one of Claims 1-4. Therefore, the plastic hinge can be generated in the plastic hinge portion of the beam where the cross-section reducing portion of the joining plate is located before the joint portion between the column and the steel bracket. Therefore, breakage and damage of the joint between the column and the steel frame bracket can be suppressed, and the life of the building can be extended.

  In addition, when the joining plate is broken or damaged by an earthquake, the beam can be repaired by replacing the joining plate.

  Further, by providing the cross-section reduced portion on the joining plate, the workability of the cross-section reduced portion is improved and the cost is reduced as compared with the case where the cross-section reduced portion is provided on the first flange plate or the second flange plate. Can do.

  Since this invention was set as said structure, the workability of a cross-section reduction part can be improved.

It is a perspective view which shows the column beam junction structure which concerns on embodiment of this invention. It is a principal part enlarged view of the beam-column joining structure which concerns on embodiment of this invention, (A) Top view, (B) is a side view. 2A is a cross-sectional view taken along a line 1-1 in FIG. 2B, and FIG. 2B is a cross-sectional view taken along a line 2-2 in FIG. (A) is a schematic side view of the column beam connection structure which concerns on embodiment of this invention, (B) is a bending moment figure of a steel beam. It is an expanded side view of the cross-section reduction part which concerns on embodiment of this invention, and has shown typically the deformation | transformation state after plastic hinge generation | occurrence | production. (A)-(C) are top views which show the modification of the column beam junction structure which concerns on embodiment of this invention. It is a graph which shows the spring characteristic (load deformation relation) of a general disc spring.

  Hereinafter, a beam-column joint structure 13 according to an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, FIG. 2 (A), and FIG. 2 (B), a part of the frame which comprises a building is shown, and the beam 10 and the column 12 which were joined by the column beam junction structure 13 are shown. Yes.

  The beam 10 includes a bracket (steel bracket) 18 and a beam member (steel beam member) 14 joined to the bracket 18. Although not shown, the beam member 14 is disposed between a bracket 18 protruding from the column 12 and a bracket protruding from a column (not shown), and is joined to each bracket.

  The bracket 18 is made of H-shaped steel, and includes a pair of flange plates 18A (first flange plates) opposed in the vertical direction, and a web 18B that connects these flange plates 18A. The bracket 18 protrudes from the side surface of the column 12.

  The column 12 is formed of a square steel pipe, and a pair of diaphragms 16 are provided therein. The diaphragm 16 is joined along the inner peripheral wall of the pillar 12 by welding or the like, and reinforces the joint between the pillar 12 and the bracket 18. The bracket 18 and the diaphragm 16 are previously joined to the column 12 by welding or the like in a factory or the like.

  A beam member 14 is disposed at a position facing the end of the bracket 18. The beam member 14 is made of H-shaped steel, and includes a pair of flange plates 14A (second flange plates) opposed in the vertical direction and a web 14B that connects these flange plates 14A. A gap for absorbing construction errors is provided between the flange plate 14A of the beam member 14 and the flange plate 18A of the bracket 18. Further, the flange plate 14 </ b> A and the flange plate 18 </ b> A are joined via joint plates 20 and 21.

  The joining plate 20 is made of a steel plate and is superimposed on the flange plate 18A and the flange plate 14A from the outside in the vertical direction of the bracket 18 and the beam member 14, respectively. On the side surface of the joining plate 20 (the side surface along the material axis direction of the beam member 14), a concave notch 26 is formed. The cutout portion 26 forms a cross-sectionally reduced portion 20 </ b> A in the joining plate 20 that is uniform or substantially uniform. As shown in FIG. 3B, the cross-sectional area 20A has a smaller cross-sectional area than other portions of the joining plate 20 (see FIG. 3A). That is, the effective sectional area that can resist the axial force caused by the bending moment acting on the beam 10 is small.

  The joining plate 21 is made of a steel plate, and is superimposed on the flange plate 18A and the flange plate 14A from the inside in the vertical direction of the bracket 18 and the beam member 14, respectively. The joining plate 21 is disposed on both sides of the webs 18B and 14B. On the side surface of the joining plate 21 (side surface along the material axis direction of the beam member 14), a concave notch 28 is formed. The cutout portion 28 forms a cross-sectionally reduced portion 21 </ b> A in the joining plate 21 that is uniform or substantially uniform. The cross-sectional area of the cross-sectionally reduced portion 20 </ b> A is made smaller than other portions of the joining plate 21. That is, the effective sectional area that can resist the axial force caused by the bending moment acting on the beam 10 is small. In this way, the bending strength of the beam 10 is partially reduced by the cross-section decreasing portions 20A and 21A formed in the joining plates 20 and 21.

  The joining plates 20 and 21 are arranged such that the respective cross-section decreasing portions 20A and 21A are located (gap) between the flange plate 18A and the flange plate 14A. The flange plate 18A and the joining plates 20, 21 and the flange plate 14A and the joining plates 20, 21 include a plurality of high-strength bolts 22 (joining means) and a nut 24 (joining means) attached to the high-strength bolts 22. Are friction bonded. Thereby, a bending moment can be transmitted between the bracket 18 and the beam member 14.

  Each high-strength bolt 22 is attached via a disc spring (elastic body) 32. The disc spring 32 is sandwiched between the head of the high-strength bolt 22 and the joining plate 20 and is held in a compressed state. Instead of the disc spring 32, a general spring washer, a corrugated washer, or the like may be used.

  Further, instead of the high-strength bolt 22 as a joining means, it may be joined by a normal bolt, a shear pin, a rivet, welding or the like, but from the viewpoint of joining strength, friction joining with the high-strength bolt 22 is preferable.

  A steel reinforcing plate 30 is overlaid on the web 18B of the bracket 18 and the web 14B of the beam member 14, and is frictionally joined by a high strength bolt 34 and a nut (not shown). The reinforcing plate 30 mainly transmits a shearing force acting on the beam 10.

  Here, the cross-sectional area of the cross-sectionally reduced portions 20A and 21A is the part of the beam 10 where the cross-sectionally reduced portions 20A and 21A are located before the joint between the column 12 and the bracket 18 (hereinafter referred to as “plastic hinge portion”). It is designed to generate a plastic hinge.

That is, as shown in FIGS. 4A and 4B, the bending moment generated in the beam 10 at the time of an earthquake is generally maximum at the joint L ₀ between the column 12 and the bracket 18, and the column 12 Smaller as you move away from Therefore, the bending strength of the beam 10 is equal in the entire cross-section, first plastic hinge occurs in joints L _0. When a plastic hinge is generated at the joint L ₀ , repeated rotational motion is generated, and a crack due to poor welding or the like may enter the joint between the column 12 and the bracket 18, leading to a brittle fracture.

As a countermeasure against this, in the beam-column joint structure 13, the axial strength of the cross-sectionally reduced portions 20 </ b> A and 21 </ b> A is designed so that the plastic hinge is generated in the plastic hinge portion of the beam 10 before the joint portion L ₀ . The shaft strength, the shape of the notch 26, the size, material of reduced cross section 20A, 21, the joint _{L 0} from the reduced cross section 20A, is designed in consideration of the distance _{L 1,} etc. up to 21A.

  Next, the effect | action of the column beam junction structure 13 which concerns on embodiment is demonstrated.

  The joining plate 20 is provided with a cross-sectionally reduced portion 20A. The cross-sectional reduced portion 20 </ b> A has a smaller cross-sectional area than other parts of the joining plate 20, i.e., has a smaller axial strength than other parts of the joining plate 20. The part of the beam 10 where the cross-section reducing parts 20A and 21A are located is a plastic hinge part, and the bending strength of the beam 10 is partially reduced. The axial strength of the reduced section 20A is increased or decreased depending on the shape, size, etc. of the notch 26, and during the earthquake, the reduced section 20A becomes plastic and ahead of the joint between the column 12 and the flange plate 18A of the bracket 18. In addition, the plastic hinge is designed to be generated in the plastic hinge portion of the beam 10 where the cross-sectionally reduced portion 20A is located. In addition, although description is abbreviate | omitted, the cross-section reduction | decrease part 21A similar to the cross-section reduction | decrease part 20A is formed in the joining plate 21. FIG.

  Therefore, when an external force is applied to the frame during an earthquake, first, the cross-section reduced portions 20A and 21A of the joining plates 20 and 21 are plasticized, and a plastic hinge is formed in the plastic hinge portion of the beam 10 where the cross-section reduced portions 20A and 21A are located. appear. Therefore, a bending moment greater than the bending strength of the plastic hinge portion does not act on the joint between the column 12 and the bracket 18. Therefore, compared to the case where the plastic hinge portion is not provided, the bending moment acting on the joint portion between the column 12 and the bracket 18 is reduced, and breakage, damage, and the like of the joint portion can be suppressed.

  Further, these cross-section decreasing portions 20A, 21A are provided on the joining plates 20, 21. Therefore, it becomes easy to manufacture the cross-section reducing portions 20A and 21A, that is, the notches 26 and 28 are easily processed. Therefore, the manufacturing cost can be reduced as compared with the conventional case where a notch is formed in a beam (for example, an H-shaped steel flange).

  In addition, by generating a plastic hinge in the plastic hinge portion of the beam 10 where the cross-section decreasing portions 20A and 21A are located, the damage and damage of the beam 10 during an earthquake can be concentrated on the joining plate. Therefore, the beam 10 can be repaired by exchanging the damaged and damaged joining plates 20 and 21. Furthermore, since the joining plates 20 and 21 can be applied to general bracket-type column beam joints, the joint plates 20 and 21 have high versatility. Also, by increasing or decreasing the cross-sectional areas of the cross-section reducing portions 20A and 21A, The bending strength can be adjusted.

  By the way, in order to ensure sufficient joint strength, steel plates having the same strength as the flange plate 18A of the bracket 18 and the flange plate 14A of the beam member 14 are used for the joint plates 20 and 21. The thickness is usually equal to or greater than or equal to the plates 18A and 14A. In this embodiment, the joint plates 20 and 21 in which strength (axial strength) is regarded as important in this way are intentionally provided with the cross-sectionally reduced portions 20A and 21A, thereby improving the toughness and deformation performance of the entire frame and improving the earthquake resistance. As well as improving the workability of the cross-sectionally reduced portions 20A and 21A.

  Next, a mechanism for transmitting a bending moment acting on the beam 10 will be described.

  When an external force acts on the frame due to an earthquake or the like, a bending moment acts on the beam 10. This bending moment is transmitted as an axial force to the flange plate 14A of the beam member 14, the joining plates 20, 21 and the flange plate 18A of the bracket 18. Between the flange plate 14 </ b> A and the joining plates 20, 21, axial force is transmitted by the frictional force generated on the contact surface between the flange plate 14 </ b> A and the joining plates 20, 21 (friction force according to the axial force of the high strength bolt 22). Is done. In this case, the flange plate 14A and the joining plates 20 and 21 bear the axial force at the portion where the flange plate 14A and the joining plates 20 and 21 overlap, but the joining plate 20 and the flange plate 18A are between the flange plate 14A and the flange plate 18A. Only 21 bears the axial force. That is, the degree of stress acting on the joining plates 20 and 21 increases between the flange plate 14A and the flange plate 18A. In the present embodiment, the cross-section decreasing portions 20A and 21A are provided at the portions of the joining plates 20 and 21 where the degree of stress increases in this way. Thereby, plastic deformation can be concentrated on the cross-section reducing portions 20A and 21A, and the plastic hinge can be more reliably generated in the plastic hinge portion of the beam 10 where the cross-section reducing portion is located.

Each high-strength bolt 22 is attached via a disc spring 32. Thereby, the fall of the transmission efficiency of the bending moment of the bracket 18 and the beam member 14 can be suppressed efficiently. Here, as shown in FIG. 5, when the beam member 14 is deformed in the direction of the arrow A and a plastic hinge is generated in the plastic hinge portion of the beam 10 where the cross-section decreasing portions 20A and 21A are positioned, the plastic hinge portion is extended and deformed. As a result, the thicknesses of the reduced sections 20A and 21A and the periphery thereof are reduced (for example, plate thickness t ₀ → plate thickness t ₁ ), and between the bonding plates 20 and 21 and the flange plate 18A, or between the bonding plates 20 and 21 There may be a gap between the flange plate 14A and the flange plate 14A. When this gap is generated, the introduction axial force of the high-strength bolt 22 acting between the joining plates 20 and 21 and the flange plate 14A or the flange plate 18A is reduced. Therefore, the friction joint strength by the high-strength bolt 22 and the nut 24 is lowered, and the transmission efficiency of the bending moment is lowered.

  As a countermeasure, in the present embodiment, a disc spring 32 is provided between the high-strength bolt 22 and the joining plate 20. As a result, even if the plate thicknesses of the cross-section reducing portions 20A and 21A and the peripheral portions thereof are reduced, the gap between the joining plates 20 and 21 and the flange plates 18A and 14A is suppressed by the restoring force of the disc spring 32. It is possible to suppress a decrease in the introduction axial force due to the force bolt 22. Therefore, the friction bonding strength is ensured, and the decrease in the bending moment transmission efficiency between the bracket 18 and the beam member 14 is reduced.

  In addition, the reduction rate of the plate | board thickness of the joining plates 20 and 21 by plasticization becomes large as it approaches the cross-section reduction | decrease part 20A, 21A. Therefore, it is desirable to provide the disc spring 32 between the high-strength bolt 22 and the joining plate 20 in the row closest to the cross-section reducing portions 20A and 21A (the row surrounded by the dotted line C in FIG. 2A). Thereby, the clearance gap between the joining plates 20 and 21 and the flange plates 18A and 14A can be efficiently suppressed. Needless to say, the disc spring 32 may be appropriately provided at a portion where the thickness reduction of the joining plates 20 and 21 is a concern.

  Furthermore, by using the disc spring 32 as the elastic body, it is possible to more reliably suppress a decrease in the transmission efficiency of the bending moment, and it is possible to suppress a decrease in the introduced axial force due to the high strength bolt 22. That is, the friction bonding strength can be maintained, and a decrease in bending moment transmission efficiency can be more reliably suppressed. This is because the disc spring 32 can obtain a large restoring force with a small amount of deflection as compared with a general spring washer or the like.

  Further, as can be seen from the spring characteristic 92 (load deformation relationship) of a general disc spring shown in FIG. 7, the disc spring has a region R in which the fluctuation of the restoring force is small with respect to the deformation amount. Therefore, by applying a pressure (initial pressure) to the disc spring 32 so that the disc spring 32 is deformed in the region R, it is possible to efficiently suppress a decrease in the introduced axial force by the high strength bolt 22. Therefore, it is desirable to use the disc spring 32 in the region R. Of course, the disc spring 32 may be used in a region outside the region R.

  In this embodiment, the disc springs 32 are provided on all the high-strength bolts 22. However, the present invention is not limited to this, and the disc springs 32 may be provided only on the high-strength bolts 22 in the row closest to the cross-section reducing portions 20A and 21A. Alternatively, the disc springs 32 may be provided only on the high-strength bolts 22 in the second closest row from the cross-section decreasing portions 20A and 21A. Further, in the present embodiment, the disc spring 32 is provided between the high-strength bolt 22 and the joining plate 20, but the disc spring 32 may be provided between the nut 24 and the joining plate 21. That is, it is sufficient that the disc spring 32 is sandwiched between at least one of the high strength bolt 22 and the joining plate 20 and between the nut 24 and the joining plate 21.

  Further, the shape and size of the notches 26 and 28 can be appropriately changed. For example, as shown in FIG. 6A, a notch 36 having a larger radius of curvature than the notch 26 (see FIG. 2A) may be formed. In addition, instead of forming the notch 26, as shown in FIG. 6B, one or a plurality of through holes 40 (five in FIG. 6B) are formed to form the bonding plate 20. The cross-sectional area may be reduced. In this case, the shape of the through hole 40 is not limited to a circle but may be a polygon such as a triangle or a quadrangle. Moreover, it is also possible to use the through-hole (bolt hole) for letting a volt | bolt pass as a through-hole for a cross-sectional reduction part. Furthermore, instead of forming the notches 26 and 28 and the through holes 40 in the joining plates 20 and 21, it is also possible to partially reduce the plate thickness of the joining plates 20 and 21 to provide a reduced section. is there.

  Moreover, in the said embodiment, although the two joining plates 20 and 21 were arrange | positioned at the up-down direction both sides of flange plate 18A, 14A, it is sufficient if there is at least one joining plate. Moreover, the joining plates 20 and 21 can be formed with various steel materials. In particular, by forming the joining plates 20 and 21 with a low yield point steel (for example, LY225) having a yield point smaller than that of ordinary steel (for example, SM490, SS400, etc.), the yield load of the cross-section reduced portions 20A and 21A can be reduced. Therefore, the plastic hinge is likely to be generated in the plastic hinge portion of the beam 10 where the cross-section decreasing portions 20A and 21A are located. Accordingly, it is possible to reduce cross-sectional defects due to the notches 26, 28 and the like, and it is possible to further reduce the labor for processing the notches 26, 28 and the like. Furthermore, vibration energy can be absorbed by a stable hysteresis loop by plasticizing the low yield point steel.

  Moreover, in this embodiment, although the cross-section reduction | decrease part 20A, 21A was provided between the flange plate 18A of the bracket 18 and the flange plate 14A of the beam member 14, (it does not restrict to this). A plastic hinge may be generated in the plastic hinge portion of the beam 10 prior to the joint portion between the column 12 and the bracket 18, and the cross-section reducing portions 20 </ b> A and 21 </ b> A may be provided at any position of the joint plates 20 and 21. For example, as shown in FIG. 6C, a through hole 40 may be formed at a position deviated from between the flange plate 18A and the flange plate 14A (gap) to form the cross-sectionally reduced portion 20A. As described above, the load axial force of the joining plates 20 and 21 caused by the bending moment of the beam 10 becomes the maximum between the flange plate 18A and the flange plate 14A. It is reasonable to provide the cross-sectionally reduced portion 20A between them.

  In addition, the column beam connection structure 13 of the present embodiment does not need to be applied to both ends of the beam member 14, and may be applied to at least one end of the beam member 14. Further, the column beam connection structure 13 can be applied to the column 12, the bracket 18, and the beam member 14 of various structures (for example, H-shaped steel, T-shaped steel, I-type, round-shaped steel, etc.). Furthermore, in the above-described embodiment, the column 12 is reinforced by the diaphragm 16 (so-called inner diamond type). However, the present invention is not limited to this, and various reinforcing types such as a so-called through-diameter type and an outer-diameter type can be used.

  Moreover, the column beam connection structure according to the above-described embodiment may be used for a part of the building or may be used for all of the building. Furthermore, the present invention can be applied to new buildings and renovated buildings.

  As mentioned above, although the example of embodiment of this invention was demonstrated, this invention is not limited to such embodiment, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect. .

12 Column 13 Column beam connection structure 14A Flange plate (second flange plate)
14 Beam members (steel beam members)
18A flange plate (first flange plate)
18 Bracket (steel bracket)
20 Joining plate 20A Cross-sectional reduction part 21 Joining plate 21A Cross-section reduction part 22 High-strength bolt (joining means)
24 Nut (joining means)
32 Belleville spring (elastic body)

Claims (5)

A steel bracket protruding from the column;
A steel beam member joined to the steel bracket;
A steel joining plate superimposed on a first flange plate of the steel bracket and a second flange plate of the steel beam member;
A cross-sectionally reduced portion that is provided on the joining plate and has a smaller cross-sectional area than other parts of the joining plate;
Joining means for joining the joining plate to the first flange plate and the second flange plate;
Column beam connection structure. The joining means includes a plurality of high-strength bolts penetrating the joining plate and the first flange plate or the second flange plate, and nuts attached to the high-strength bolts,
The beam-column joining structure according to claim 1, wherein an elastic body is sandwiched between the high-strength bolt or the nut and the joining plate.   The column beam connection structure according to claim 2, wherein the elastic body is a disc spring.   The column beam connection structure according to any one of claims 1 to 3, wherein the cross-sectionally reduced portion is provided between the first flange plate and the second flange plate.   The building which has the said column joined by the beam-column joining structure of any one of Claims 1-4, and the said steel beam member.

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