JP2015214807A - Heterogeneous steel beam joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a labor of jointing work of steel beam members having different beam depths.SOLUTION: A heterogeneous steel beam joint structure 10 includes: a first steel beam member 20 jointed to a column 14; a second steel beam member 30 having a smaller beam depth than the first steel beam member 20, arranged so that an upper flange part 20U continues from an upper flange part 20U of the first steel beam member 20, and not jointed to the upper flange part 20U; and joint plates 40 arranged over each of web parts 20W of the first steel beam member 20 and the second steel beam member 30 and jointed with bolts to the web parts 20W respectively.

Description

  The present invention relates to a heterogeneous steel beam joint structure.

  A boundary beam damper is known in which web portions of adjacent steel beam members are joined with a bolt and a nut via a splice plate (see, for example, Patent Document 1).

  In addition, there is known a reinforcing structure of an open steel beam in which a splice plate is disposed above and below an opening formed over the web portion of adjacent steel beam members (see, for example, Patent Document 2).

JP 2003-064901 A JP-A-5-179756

  By the way, there is a desire to simplify the method of joining adjacent steel beam members. In particular, in the case of a hunched steel beam, steel beam members having different beam formations are joined to each other, so that the joining work may take time.

  In view of the above facts, an object of the present invention is to reduce the labor of joining steel beam members having different beam formations.

  The dissimilar steel beam joint structure according to claim 1 has a first steel beam member joined to a column, a beam formation lower than that of the first steel beam member, and an upper flange portion of the first steel beam member. A second steel beam member disposed so as to be continuous with the upper flange portion and not joined to the upper flange portion, and the web portions of the first steel beam member and the second steel beam member. And a joining plate that is respectively bolted to the web portion.

  According to the heterogeneous steel beam joint structure according to claim 1, the upper flange portions of the first steel beam member and the second steel beam member are not joined to each other, and the web of the first steel beam member and the second steel beam member is used. The parts are bolted together via a joining plate.

  Therefore, for example, compared with the case where the upper flange portions of the first steel beam member and the second steel beam member are welded together and the web portions are welded together via the joining plate, the first steel beam member and the second steel beam member It is possible to reduce the labor of joining the two steel beam members.

  The dissimilar steel beam joint structure according to claim 2 is the dissimilar steel beam joint structure according to claim 1, wherein the joint plate extends in an out-of-plane direction from a lower part of the joint plate, and the first steel beam A stress transmission rib portion facing each of the member and the lower flange portion of the second steel beam member is provided.

  According to the dissimilar steel beam joining structure according to claim 2, the joining plate is provided with the stress transmission rib portion. The stress transmission rib portion extends in the out-of-plane direction from the lower portion of the joining plate, and faces each of the lower flange portions of the first steel beam member and the second steel beam member.

  Here, since the first steel beam member and the second steel beam member are arranged so that their beam formations are different and their upper flange portions are continuous, their lower flange portions are not continuous. Therefore, it is difficult to transmit stress between these lower flange portions.

  On the other hand, in this invention, the stress transmission rib part facing each of the lower flange part of a 1st steel beam member and a 2nd steel beam member is provided in the lower part of a joining plate. Thereby, stress is transmitted between the lower flange portions of the first steel beam member and the second steel beam member via the stress transmission rib portion.

  Further, since the first steel beam member is reinforced by the stress transmission rib portion, buckling (lateral buckling) or the like of the lower flange portion of the first steel beam member is suppressed.

  As described above, in the present invention, it is possible to suppress the buckling of the lower flange portion of the first steel beam member while improving the stress transmission between the lower flange portions of the first steel beam member and the second steel beam member. .

  The dissimilar steel beam joint structure according to claim 3 is the dissimilar steel beam joint structure according to claim 1, wherein the dissimilar steel beam joint structure is overlapped with the web portion of the first steel beam member and is bolt-joined and the web portion is A base plate portion extending to a lower side of a lower flange portion of the second steel beam member; and provided along an upper end portion of the base plate portion, spanning the first steel beam member and the second steel beam member, and The stress transmission member which has a stress transmission rib part piled up and bolted to the said lower flange part of 2 steel beam members from the lower side is provided.

  According to the heterogeneous steel beam joint structure according to the third aspect, the stress transmission member includes a base plate portion and a stress transmission rib portion provided along the upper end portion of the base plate portion. The base plate portion is overlapped with the web portion of the first steel beam member and bolted. On the other hand, the stress transmission rib portion is overlapped and bolted to the lower flange portion of the second steel beam member from the lower side. The first steel beam member and the second steel beam member are joined via the stress transmission member.

  Therefore, compared with the case where the stress transmission member is welded to each of the first steel beam member and the second steel beam member, the labor of joining the first steel beam member and the second steel beam member can be reduced. .

  Further, the stress transmission rib portion is disposed across the first steel beam member and the second steel beam member. Thereby, stress is transmitted between the lower flange portions of the first steel beam member and the second steel beam member via the stress transmission rib portion.

  Furthermore, since the first steel beam member is reinforced by the stress transmission rib portion, buckling (lateral buckling) or the like of the lower flange portion of the first steel beam member is suppressed.

  As described above, in the present invention, it is possible to suppress the buckling of the lower flange portion of the first steel beam member while improving the stress transmission between the lower flange portions of the first steel beam member and the second steel beam member. .

  As described above, according to the heterogeneous steel beam joining structure according to the present invention, it is possible to reduce the labor of joining steel beam members having different beam formations.

It is an elevation view which shows the haunch steel beam to which the dissimilar steel beam joining structure which concerns on 1st Embodiment of this invention was applied. FIG. 2 is a sectional view taken along line 2-2 of FIG. (A) is an elevation view partially showing a hunched steel beam to which the heterogeneous steel beam joint structure according to the second embodiment of the present invention is applied, and (B) is a 3B- in FIG. 3 (A). FIG. 3B is a sectional view taken along line 3B. (A) is an elevational view showing a state in which a slab is formed on the haunch steel beam shown in FIG. 3 (A), and (B) is a sectional view taken along line 4B-4B in FIG. 4 (A). is there. It is an elevation view which shows the haunch steel beam which concerns on a comparative example. (A) is an elevation view partially showing a hunched steel beam to which a heterogeneous steel beam joint structure according to a third embodiment of the present invention is applied, and (B) is a 6B- in FIG. 6 (A). It is a 6B line sectional view. (A) is an elevational view partially showing a hunched steel beam to which the heterogeneous steel beam joint structure according to the fourth embodiment of the present invention is applied, and (B) is 7B- in FIG. 7 (A). It is a 7B line sectional view.

  Hereinafter, a heterogeneous steel beam joint structure according to an embodiment of the present invention will be described with reference to the drawings.

  First, the first embodiment will be described.

  FIG. 1 shows a haunch steel beam 12 to which the heterogeneous steel beam joint structure 10 according to the first embodiment is applied. The haunch steel beam 12 is installed on a pair of columns 14. The haunch steel beam 12 includes a pair of first steel beam members 20 and a second steel beam member 30.

  The pair of first steel beam members 20 is formed of H-shaped steel, and includes a pair of upper flange portion 20U and lower flange portion 20L opposed in the vertical direction, and a pair of upper flange portion 20U and lower flange portion 20L. It has the web part 20W to connect. One end portion of each first steel beam member 20 in the material axis direction is joined to the joint portion 14 </ b> A of the column 14.

  Specifically, a gusset plate 16 and a pair of upper and lower diaphragms 18 are provided in the joint portion 14 </ b> A of the column 14. The gusset plate 16 is joined to the side surface of the column 14 by welding or the like. The gusset plate 16 is bolted by a bolt 22 and a nut (not shown) in a state where the gusset plate 16 is overlaid on the web portion 20W of the first steel beam member 20.

  The pair of diaphragms 18 is, for example, a through diaphragm or an outer diaphragm, and is disposed above and below the gusset plate 16. An upper flange portion 20U and a lower flange portion 20L of the first steel beam member 20 are joined to the pair of diaphragms 18 by welding or the like. Thus, one end of the first steel beam member 20 in the material axis direction is joined (rigidly joined) to the joint portion 14A of the column 14.

  Note that the column 14 is formed of, for example, a square steel pipe, a round steel pipe, an H-shaped steel, or the like. Further, the column 14 is not limited to a steel structure, but may be an RC structure, an SRC structure, or a CFT structure.

  A second steel beam member 30 is disposed between the pair of first steel beam members 20. Similar to the first steel beam member 20, the second steel beam member 30 is formed of H-shaped steel, and a pair of upper flange portions 30U and a lower flange portion 30L opposed in the vertical direction, and a pair of upper flange portions. It has the web part 30W which connects 30U and the lower flange part 30L.

Here, the beam component H ₂ of the second steel beam member 30 is set lower than the beam component H _{1 of} the first steel beam member 20. In other words, haunch steel beam 12, RyoNaru of H ₂ Material axial intermediate portion is lower than RyoNaru H ₁ axis of member opposite sides (column 14 side). Thereby, weight reduction of the haunch steel beam 12 is achieved, ensuring the rigidity and proof strength of the column 14 side in the haunch steel beam 12.

In addition, the plate | board thickness and width | variety of upper flange part 20U and 30U may be the same, and the 1st steel beam member 20 and the 2nd steel beam member 30 may differ. The same applies to the lower flange portions 20L and 30L and the web portions 20W and 30W. The first steel beam member 20 and the second steel beam member 30 may be made of the same material (strength) or different. Furthermore, as long as the materials are different, the beam formations H ₁ and H _{2 of} the first steel beam member 20 and the second steel beam member 30 may be the same. Furthermore, the first steel beam member and the second steel beam member are not limited to H-shaped steel. The first steel beam member and the second steel beam member need only have at least a web portion and an upper flange portion, and may be, for example, an I-shaped steel, a C-shaped steel, a T-shaped steel, or the like. Further, for example, one of the first steel beam member and the second steel beam member may be formed of H-section steel, and the other may be formed of C-section steel or the like.

  Both ends of the second steel beam member 30 in the material axis direction are joined to the other ends of the pair of first steel beam members 20 in the material axis direction, respectively. Specifically, the second steel beam member 30 is arranged such that its upper flange portion 30U is continuous with the upper flange portion 20U of the first steel beam member 20, and its lower flange portion 30L is the first steel beam. The member 20 is positioned above the lower flange portion 20L. Therefore, a step is formed between the lower flange portion 30L and the lower flange portion 20L. Thereby, installation space, such as installation wiring and piping, is formed under the 2nd steel beam member 30. As shown in FIG.

  Note that the upper flange portion 20U of the first steel beam member 20 and the upper flange portion 30U of the second steel beam member 30 are continuous here because the upper flange portions 20U and 30U are displaced in the vertical direction due to construction errors or the like. In addition, it is a concept including a configuration that shifts in the width direction of the upper flange portions 20U and 30U. Further, the upper flange portion 30U of the second steel beam member 30 and the upper flange portion 30U of the first steel beam member 20 are not joined, and are not joined by welding or bolts.

  As shown in FIGS. 1 and 2, the web portions 20 </ b> W and 30 </ b> W of the first steel beam member 20 and the second steel beam member 30 are bolted via a pair of bonding plates 40. Specifically, the pair of joining plates (flat plates) 40 are formed in a rectangular flat plate shape, and are in the out-of-plane direction of the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30. Located on both sides. In addition, the shape of the joining plate 40 is not limited to a rectangular shape, and may be a polygonal shape or an elliptical shape.

  Each joining plate 40 is arranged over the web portions 20W, 30W of the first steel beam member 20 and the second steel beam member 30, and a plurality of bolts 42 in a state of being superimposed on each of these web portions 20W, 30W. And a bolt 44 with a nut 44. In other words, the pair of joining plates 40 are connected to each other by the plurality of bolts 42 and the nuts 44 with the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30 sandwiched from both sides in the out-of-plane direction. It is bolted. Thereby, the web parts 20W and 30W of the 1st steel beam member 20 and the 2nd steel beam member 30 are pin-joined, and shear force is transmitted between the web parts 20W and 30W via a pair of joining plates 40. It has come to be. The bolt 42 may be a high-strength bolt or a normal bolt.

  Next, the operation of the first embodiment will be described.

  As shown in FIGS. 1 and 2, according to the dissimilar steel beam joint structure 10 according to the present embodiment, the upper flange portions 20U and 30U of the first steel beam member 20 and the second steel beam member 30 are not joined to each other. In addition, the web portions 20 </ b> W and 30 </ b> W of the first steel beam member 20 and the second steel beam member 30 are bolt-bonded via a pair of bonding plates 40.

  Therefore, for example, the upper flange portions 20U and 30U of the first steel beam member 20 and the second steel beam member 30 are welded together and the web portions 20W and 30W are welded and joined via the pair of joining plates 40. In comparison, the labor of joining the first steel beam member 20 and the second steel beam member 30 can be reduced.

  Further, in bolt joining, nondestructive inspection (UT) required for welding joining is not necessary. Therefore, the temporary storage space of the 1st steel beam member 20 and the 2nd steel beam member 30 until a nondestructive inspection (UT) is completed can be made unnecessary.

  Furthermore, since the bolt joint is easy to construct, a skilled worker is unnecessary, and the joint quality equivalent to that of the factory can be ensured on site. Therefore, the 1st steel beam member 20 and the 2nd steel beam member 30 can be conveyed to the field in the state where it divided, and the 1st steel beam member 20 and the 2nd steel beam member 30 can be joined on the field. Therefore, the transportability and liftability of the first steel beam member 20 and the second steel beam member 30 are improved.

  Furthermore, for example, the first steel beam member 20 and the second steel beam member 30 are joined at the first or second inflection point where the bending moment due to the long-term load is zero or near the inflection point. The joining structure of the steel beam member 20 and the second steel beam member 30 can be rationally simplified.

  Next, a second embodiment will be described. In addition, the thing of the same structure as 1st Embodiment attaches | subjects a same sign, and abbreviate | omits description.

  3 (A) and 3 (B) show a hunched steel beam 52 to which the dissimilar steel beam joint structure 50 according to the second embodiment is applied. In the second embodiment, unlike the first embodiment, a stress transmission rib portion 54 </ b> B is provided on the bonding plate 54.

  Specifically, the pair of joining plates 54 is formed in an L-shaped cross section, and is disposed on both sides of the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30 in the out-of-plane direction. ing. Each joining plate 54 has a base plate portion (flat plate portion) 54A and a stress transmission rib portion 54B. The joining plate 54 may be an unequal angle iron or an equal angle iron. The joining plate 54 may be channel steel.

  The base plate portion 54A is formed in a rectangular flat plate shape. The base plate portion 54A is disposed over the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30, and a plurality of bolts are overlaid on the web portions 20W and 30W. The bolts are joined by 56A and 56B and a nut 58. In other words, the pair of base plate portions 54A includes a plurality of bolts 56A, 56B and nuts 58 with the web portions 20W, 30W of the first steel beam member 20 and the second steel beam member 30 sandwiched from both sides in the out-of-plane direction. Are bolted together. Thereby, the 1st steel beam member 20 and the 2nd steel beam member 30 are pin-joined.

  The stress transmission rib portion 54B is provided along the lower end portion of the base plate portion 54A, and is disposed across the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30. The stress transmission rib portion 54B extends in the out-of-plane direction from the lower end portion of the base plate portion 54A. That is, the stress transmission rib portion 54 </ b> B stands substantially perpendicular to the surfaces (side surfaces) of the web portions 20 </ b> W and 30 </ b> W of the first steel beam member 20 and the second steel beam member 30. The web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30 are reinforced by the stress transmission rib portion 54B.

  Moreover, the stress transmission rib part 54B is arrange | positioned above the lower flange part 30L of the 2nd steel beam member 30, and has opposed the said lower flange part 30L. The stress transmission rib portion 54B extends from the web portion 30W of the second steel beam member 30 to the web portion 20W of the first steel beam member 20 along the lower flange portion 30L, and the lower flange portion of the first steel beam member 20 It faces 20L. Stress is transmitted between the lower flange portion 30L of the second steel beam member 30 and the lower flange portion 20L of the first steel beam member 20 through the stress transmission rib portion 54B.

  Note that the bonding plate 54 is not limited to an L-shaped section, and may have a T-shaped section. That is, the stress transmission rib portion 54B is not limited to the lower end portion of the base plate portion 54A, and may be provided in a lower portion other than the lower end portion.

  Here, in this embodiment, the bolts 56A and 56B are arranged in a plurality of stages and a plurality of rows. The number of the lowest bolts 56B, that is, the number (rows) of the bolts 56B on the stress transmission rib portion 54B side is larger than the number (rows) of the upper bolts 56A. Further, the lowermost bolt 56B is arranged along the stress transmission rib portion 54B. With these bolts 56B, the stress transmission efficiency between the web portions 20W, 30W of the first steel beam member 20 and the second steel beam member 30 and the stress transmission rib portion 54B is improved. The number and arrangement of the bolts 56A and 56B can be changed as appropriate.

  As shown in FIGS. 4A and 4B, a slab 60 made of, for example, reinforced concrete is formed on the first steel beam member 20 and the second steel beam member 30. An upper end slab bar 62 and a lower end slab bar 64 are embedded in the slab 60 in two horizontal directions. The slab 60 is joined to the first steel beam member 20 and the second steel beam member 30 through a plurality of studs 66.

  Specifically, a plurality of studs 66 as shear force transmission members are provided on the upper surfaces of the upper flange portions 20U and 30U of the first steel beam member 20 and the second steel beam member 30, respectively. By embedding these studs 66 on the lower surface side of the slab 60, the first steel beam member 20, the second steel beam member 30, and the slab 60 are integrated. The slab 60 is a synthetic slab using a deck plate (not shown).

  Here, a plurality of stress transmission bars (reinforcing bars) 68 are embedded in the peripheral portion of the stud 66 in the slab 60 along the material axis direction of the hunch steel beam 52. The plurality of stress transmission bars 68 are arranged between the upper end slab bars 62 and the lower end slab bars 64, and are arranged at intervals in the out-of-plane direction (arrow X direction) of the web portions 20W and 30W. . Each stress transmission bar 68 has a diameter larger than that of the upper end slab bar 62 and the lower end slab bar 64.

  As a result, stress is transmitted between the upper flange portions 20U and 30U of the first steel beam member 20 and the second steel beam member 30 via the stress transmission bars 68 and the studs 66. That is, the stress transmission line 68 and the stud 66 form a stress transmission path between the upper flange portions 20U and 30U in the slab 60.

  In addition, the number and arrangement | positioning of the stress transmission line 68 and the stud 66 can be changed suitably. Further, the stress transmission line 68 and the stud 66 may be appropriately bound by a binding wire or the like.

  Next, the operation of the second embodiment will be described.

  As shown in FIG. 3A and FIG. 3B, according to the dissimilar steel beam joining structure 50 according to the present embodiment, the joining plate 54 includes the first steel beam member 20 and the second steel beam member. The stress transmission rib part 54B over 30 web parts 20W and 30W is provided. The stress transmission rib portion 54B extends in the out-of-plane direction from the lower end portion of the base plate portion 54A, and faces the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30.

Here, the first steel beam member 20 and the second steel beam member 30 are arranged such that the beam formations H ₁ and H ₂ are different and the upper flange portions 20U and 30U are continuous with each other. Therefore, the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30 are not continuous with each other, and a step is formed therebetween. Therefore, it is difficult to transmit stress between the lower flange portions 20L and 30L.

  On the other hand, in this embodiment, the joining plate 54 is provided with stress transmission ribs 54 </ b> B extending over the web portions 20 </ b> W and 30 </ b> W of the first steel beam member 20 and the second steel beam member 30. Thereby, for example, the stress (tensile stress) acting on the lower flange portion 30L of the second steel beam member 30 is a stress transmission rib via the web portion 30W, the bolt 56B, and the base plate portion 54A on the second steel beam member 30 side. Is transmitted to the unit 54B. Further, the stress transmitted to the stress transmission rib portion 54B is transmitted to the lower flange portion 20L of the first steel beam member 20 through the base plate portion 54A, the bolt 56B, and the web portion 20W on the first steel beam member 20 side. Is done.

  In the present embodiment, among the plurality of stages of bolts 56A and 56B, the number of lowermost bolts 56B (number of rows) is larger than the number of upper bolts 56A (number of rows). Thereby, the stress transmission between the web parts 20W and 30W of the 1st steel beam member 20 and the 2nd steel beam member 30 and the stress transmission rib part 54B becomes favorable. Therefore, the stress transmission efficiency between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30 is improved.

  Furthermore, buckling (lateral buckling) or the like of the lower flange portion 20L of the first steel beam member 20 is suppressed by the stress transmission rib portion 54B. Therefore, the proof stress of the junction part of the 1st steel beam member 20 and the 2nd steel beam member 30 can be improved.

  Further, the joining plate 54 provided with the stress transmission rib portion 54 </ b> B is bolted to the web portion 20 </ b> W of the first steel beam member 20. Therefore, for example, as in the comparative example shown in FIG. 5, the first steel beam member 20 is manufactured as compared with the configuration in which the stiffening rib 100 for buckling prevention is welded to the web portion 20 </ b> W of the first steel beam member 20. Improves.

  Thus, in the present embodiment, the seat of the lower flange portion 20L of the first steel beam member 20 is improved while the stress transmission between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30 is improved. Bending and the like can be suppressed.

  Further, as shown in FIGS. 4A and 4B, the slab 60 formed on the first steel beam member 20 and the second steel beam member 30 has a plurality of stress transmission bars (reinforcement). (Stripes) 68 are buried. Stress is transmitted between the upper flange portions 20U and 30U of the first steel beam member 20 and the second steel beam member 30 through the stress transmission bars 68 and the studs 66.

  Therefore, the first steel beam member 20 and the second steel beam member 30 can be joined to each other without joining the upper flange portions 20U, 30U of the first steel beam member 20 and the second steel beam member 30 directly by welding or the like. The yield strength of the joint can be increased.

  The configuration in which the stress transmission path 68 and the stud 66 form the stress transmission path between the upper flange portions 20U and 30U in the slab 60 is also appropriate for the first embodiment and the third and fourth embodiments described later. Applicable.

  Next, a third embodiment will be described. In addition, the thing of the same structure as 1st, 2nd embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  6A and 6B show a hunched steel beam 72 to which the heterogeneous steel beam joint structure 70 according to the third embodiment is applied. In the third embodiment, unlike the first and second embodiments, a pair of first steel beam members 20 and a second steel beam member 30 are bolted via a pair of joining plates 74 and a pair of stress transmission members 80. It is joined.

  Specifically, the pair of joining plates 74 has the same configuration as the joining plate 40 (see FIG. 1) in the first embodiment, and is formed in a rectangular flat plate shape. The pair of joining plates 74 are disposed on both sides in the out-of-plane direction of the web portions 20 </ b> W and 30 </ b> W of the first steel beam member 20 and the second steel beam member 30. It is bolted to 20W and 30W, respectively. The pair of joining plates 74 mainly transmits a shearing force between the web portions 20 </ b> W and 30 </ b> W of the first steel beam member 20 and the second steel beam member 30.

  On the other hand, the pair of stress transmission members 80 are formed in an L-shaped cross section, and are disposed on both sides of the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30 in the out-of-plane direction. . Each stress transmission member 80 has a base plate portion 80A and a stress transmission rib portion 80B, and is arranged in a state where the longitudinal direction is the material axis direction of the hunch steel beam 72 and the stress transmission rib portion 80B is down. Yes. The pair of stress transmission members 80 mainly transmit stress (tensile stress) between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30.

  The base plate portion 80A is formed in a rectangular flat plate shape. The base plate portion 80A is disposed over the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30, and a plurality of bolts are overlaid on the web portions 20W and 30W. 82 and nut 84 are bolted together.

  The stress transmission rib portion 80B is provided along the lower end portion of the base plate portion 80A and extends over the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30. The stress transmission rib portion 80B extends in the out-of-plane direction from the lower end portion of the base plate portion 80A. That is, the stress transmission rib portion 80B stands substantially perpendicular to the surfaces (side surfaces) of the web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30. The web portions 20W and 30W of the first steel beam member 20 and the second steel beam member 30 are reinforced by the stress transmission rib portion 80B.

  In addition, the stress transmission rib portion 80B is disposed on the upper side of the lower flange portion 30L of the second steel beam member 30, and faces the lower flange portion 30L in a close proximity. The stress transmission rib portion 80B extends from the web portion 30W of the second steel beam member 30 to the web portion 20W of the first steel beam member 20 along the lower flange portion 30L, and the lower flange portion of the first steel beam member 20 It faces 20L. Stress is transmitted between the lower flange portion 30L of the second steel beam member 30 and the lower flange portion 20L of the first steel beam member 20 through the stress transmission rib portion 80B.

  Further, the length of the stress transmission member 80 on the first steel beam member 20 side is longer than that of the second steel beam member 30 side. Further, the stress transmission member 80 extends from the second steel beam member 30 to the column 14 side than the joining plate 74. Thereby, buckling (lateral buckling) of the lower flange portion 20L of the first steel beam member 20 is more reliably suppressed.

  The length of the stress transmission member 80 can be changed as appropriate. For example, the lengths of the stress transmission member 80 on the first steel beam member 20 side and the second steel beam member 30 side may be the same. The length of the second steel beam member 30 side may be longer than that of the first steel beam member 20 side. Further, the stress transmission member 80 may have the same length as the joining plate 74 or may be shorter than the joining plate 74.

  Next, the operation of the third embodiment will be described.

  As shown in FIGS. 6A and 6B, according to the dissimilar steel beam joint structure 70 according to the present embodiment, the web portions 20W of the first steel beam member 20 and the second steel beam member 30 are provided. The joining plate 74 that transmits shearing force between 30 W and the stress transmission member 80 that transmits stress (tensile stress) between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30 are separated. It is a body (separate member).

  In this way, the joining plate 74 and the stress transmission member 80 are made separate for each function (role), so that the design of the joining plate 74 and the stress transmission member 80 is facilitated. Moreover, since each joining plate 74 and the stress transmission member 80 become light respectively compared with the case where the joining plate 74 and the stress transmission member 80 are united, workability | operativity improves.

  Further, in the present embodiment, the stress transmission member 80 extends from the second steel beam member 30 to the column 14 side rather than the joining plate 74. Thereby, the buckling (lateral buckling) of the lower flange portion 20L of the first steel beam member 20 can be more reliably suppressed. Therefore, in the present embodiment, the buckling of the lower flange portion 20L of the first steel beam member 20 is improved while improving the stress transmission between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30. Etc. can be more reliably suppressed.

  Further, the stress transmission member 80 is bolted to the first steel beam member 20 and the second steel beam member 30 in the same manner as the bonding plate 74. Therefore, compared with the case where the stress transmission member 80 is welded and joined to the first steel beam member 20 and the second steel beam member 30, respectively, the work of joining the first steel beam member 20 and the second steel beam member 30 is troublesome. Can be reduced.

  Next, a fourth embodiment will be described. In addition, the thing of the same structure as 1st-3rd embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  7A and 7B show a hunched steel beam 92 to which the heterogeneous steel beam joint structure 90 according to the fourth embodiment is applied. In the fourth embodiment, unlike the third embodiment, a pair of stress transmission members 80 are disposed below the second steel beam member 30.

  Specifically, the pair of stress transmission members 80 are arranged with the stress transmission rib portion 80B facing up. One side in the longitudinal direction (the first steel beam member 20 side) of the base plate portion 80A of the pair of stress transmission members 80 is overlaid on the web portion 20W of the first steel beam member 20 with bolts 82 and nuts (not shown). ).

  On the other hand, the other longitudinal side of the base plate portion 80A of the pair of stress transmission members 80 (the second steel beam member 30 side) is from the web portion 20W of the first steel beam member 20 to the lower flange portion 30L of the second steel beam member 30. The bolts 96 and nuts 97 are joined to each other with a plate-like spacer 94 interposed therebetween. The spacer 94 has substantially the same thickness as the web portion 20W of the first steel beam member 20. Further, the spacer 94 can be omitted as appropriate.

  The stress transmission rib portion 80B is provided along the upper end portion of the base plate portion 80A, and extends over the web portion 20W of the first steel beam member 20 and the lower flange portion 30L of the second steel beam member 30. The stress transmission rib portion 80 </ b> B is bolted by a plurality of bolts 98 and nuts 99 while being superimposed on the lower flange portion 30 </ b> L of the second steel beam member 30 from the lower side.

  Next, the operation of the fourth embodiment will be described.

  As shown in FIGS. 7A and 7B, according to the dissimilar steel beam connection structure 90 according to the present embodiment, the stress transmission rib portion 80B of the pair of stress transmission members 80 is the second steel beam. The member 30 is bolted by a bolt 98 and a nut 99 in a state of being overlapped with the lower flange portion 30L of the member 30 from below.

  Thereby, the stress (tensile stress) acting on the lower flange portion 30L of the second steel beam member 30 is directly transmitted to the stress transmission rib portion 80B. Further, the stress transmitted to the stress transmission rib portion 80B is transmitted to the lower flange portion 20L of the first steel beam member 20 through the base plate portion 80A on the first steel beam member 20 side, the bolt 82, and the web portion 20W. Is done. Therefore, the stress transmission efficiency between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30 is improved.

  In addition, by fixing the stress transmission rib portion 80B to the lower flange portion 30L of the second steel beam member 30, the degree of fixation of the stress transmission rib portion 80B is increased. Therefore, the buckling (lateral buckling) of the lower flange portion 20L of the first steel beam member 20 can be more reliably suppressed.

  Thus, in the present embodiment, the seat of the lower flange portion 20L of the first steel beam member 20 is improved while the stress transmission between the lower flange portions 20L and 30L of the first steel beam member 20 and the second steel beam member 30 is improved. Bending and the like can be suppressed.

  The stress transmission member 80 is bolted to the first steel beam member 20 and the second steel beam member 30 in the same manner as the bonding plate 40. Therefore, compared with the case where the stress transmission member 80 is welded and joined to the first steel beam member 20 and the second steel beam member 30, respectively, the work of joining the first steel beam member 20 and the second steel beam member 30 is troublesome. Can be reduced.

  Next, modified examples of the first to fourth embodiments will be described. In the following, various modified examples will be described by taking the first embodiment as an example, but these modified examples are also applicable to the second to fourth embodiments as appropriate.

  In the said 1st Embodiment, although the example which provided a pair of joining plate 40 in the both sides of the web part 20W, 30W of the 1st steel beam member 20 and the 2nd steel beam member 30 in the out-of-plane direction was shown, it does not restrict to this Absent. You may provide the joining plate 40 only in the one side of the out-of-plane direction of the web parts 20W and 30W. The same applies to the joining plate 54 in the second embodiment and the stress transmission member 80 in the third and fourth embodiments.

  Moreover, in the said 1st Embodiment, although the example which joined a pair of 1st steel beam member 20 to the both ends of the material axis direction of the 2nd steel beam member 30 was shown, it does not restrict to this. The first steel beam member 20 is joined only to one end portion of the second steel beam member 30 in the material axis direction, and the other end portion of the second steel beam member 30 in the material axis direction is joined to the joint portion 14A of the column 14. May be.

  As mentioned above, although one embodiment of the present invention was described, the present invention is not limited to such an embodiment, and one embodiment and various modifications may be used in combination as appropriate, and the gist of the present invention will be described. Of course, various embodiments can be implemented without departing from the scope.

DESCRIPTION OF SYMBOLS 10 Dissimilar steel beam joining structure 12 Haunch steel beam 14 Column 20 1st steel beam member 20U Upper flange part 20L Lower flange part 20W Web part 30 2nd steel beam member 30U Upper flange part 30L Lower flange part 30W Web part 40 Joining plate 42 Bolt 50 Heterogeneous steel beam joint structure 52 Haunch steel beam 54 Joint plate 54B Stress transmission rib part 56A Bolt 56B Bolt 70 Heterogeneous steel beam joint structure 72 Haunch steel beam 74 Joint plate 76 Bolt 80 Stress transmission member 80A Base plate part 80B Stress transmission rib part 82 Bolt 90 Heterogeneous steel beam joint structure 92 Haunch steel beam 98 Bolt

Claims (3)

A first steel beam member joined to a column;
A second steel frame in which the beam formation is lower than that of the first steel beam member, the upper flange portion is arranged so as to be continuous with the upper flange portion of the first steel beam member, and is not joined to the upper flange portion. A beam member;
A joining plate that is disposed over the web portions of the first steel beam member and the second steel beam member and is bolted to the web portions;
Dissimilar steel beam joint structure. The joint plate is provided with a stress transmission rib portion extending in an out-of-plane direction from a lower portion of the joint plate and facing each of the lower flange portions of the first steel beam member and the second steel beam member.
The heterogeneous steel beam joint structure according to claim 1. A base plate portion that is overlapped with the web portion of the first steel beam member and is bolted and extends from the web portion to a lower side of a lower flange portion of the second steel beam member; and an upper end portion of the base plate portion A stress transmission rib portion that is provided along the first steel beam member and the second steel beam member and is overlapped with the lower flange portion of the second steel beam member from below and bolt-bonded; Comprising a stress transmission member having
The heterogeneous steel beam joint structure according to claim 1.

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