JP2019190109A - Side-reinforcing rigid structure for steel beam - Google Patents

Abstract

To provide a side-reinforcing rigid structure for a steel beam, which is easily constructed and capable of suppressing the increase of a steel frame quantity and the increase of machining time and labor.SOLUTION: The side-reinforcing rigid structure comprises: a steel beam 3 that has an upper flange 6, a lower flange 7 and a web 8; a ferroconcrete slab 4 that is provided on the steel beam 3; and a plurality of bored steel-plate dowels 10 that are joined to the upper surface of the upper flange 6 and buried in the slab 4 so as to extend in a direction (X direction) orthogonal to the axial direction of the steel beam 3.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a lateral stiffening structure for a steel beam.

  The “2015 Technical Report on Structural Standards for Buildings” (hereinafter referred to as “Technical Standards Manual”), supervised by the Ministry of Land, Infrastructure, Transport and Tourism, shows the necessity of retained lateral strength for steel beams. Holding strength lateral stiffening means that, after both ends of the beam material have reached the fully plastic state, lateral buckling does not occur in the other elastic-plastic region as well as the both ends of the material that exhibits sufficient rotational capacity. Complementing such rigidity.

  The steel beam and the slab made of reinforced concrete above the steel beam are usually fastened by a headed stud. The stud is welded to the upper surface of the upper flange of the steel beam, and the horizontal force transmitted from the slab is transmitted to the steel beam through the stud. Lateral buckling is a phenomenon in which the steel beam is bent around the strong axis and the compression side protrudes out of the plane. In the technical standard manual, stiffening methods using a small beam or a cane are encouraged as a method of suppressing lateral buckling.

  Lateral buckling stiffeners such as small beams and wands can laterally stiffen steel beams, while increasing the amount of steel frames and the labor of processing steel beams. In Patent Document 1, as a structure capable of suppressing the lateral buckling of the steel beam without attaching a lateral buckling stiffener, a reinforced concrete slab provided on the steel beam is necessary for restraining the lateral movement of the steel beam. There has been proposed a composite beam structure that is joined to a flange by more than the number of studs and has torsional rigidity that constrains rotational deformation of a steel beam.

JP 2012-12788 A

  In order to confirm the lateral stiffening effect of the composite beam in which the slab is joined to the steel beam by the stud, the inventors of the present application connect a plurality of headed studs 115 to the upper flange of the steel beam 103 as shown in FIG. A composite beam test body 100 provided on the upper surface and embedded in the slab 104 was manufactured. In this test body 100, the lower end and the upper end of a pair of columns 102 to which both ends of the steel beam 103 are rigidly coupled are pin-coupled to the base member 120 and the force applying member 130. Then, in order to confirm the bearing strength of the composite beam, an experiment was performed on the composite beam in which a shearing force Q in the material axis direction was alternately applied to the test body 100. As a result, although the corresponding lateral stiffening effect by the slab 104 was confirmed, some of the headed studs 115 were broken by the applied force, and then the portion of the slab 104 that restrains the remaining headed studs 115 was cone-shaped. It was found that the function as a composite beam was lost due to destruction. And the loss of the function as a composite beam caused a large lateral buckling in the steel beam 103.

  If some of the headed studs 115 are not broken, the lateral complementary rigidity by the slab 104 is improved. In order to prevent some of the headed studs 115 from breaking, it is conceivable that the number of the headed studs 115 is considerably larger than that required for restraining the lateral movement of the steel beam 103. However, if it does so, the installation effort of the headed stud 115 to the steel beam 103 will increase.

  In view of such a background, it is an object of the present invention to provide a steel beam lateral stiffening structure that can suppress an increase in the amount of steel frames and an increase in labor for processing the steel beams.

  FIG. 13 is a plan view showing a damage state of the composite steel beam specimen 100 after the force test. In the figure, a circle indicates a broken headed stud 115, and a triangle indicates a headed stud 115 in which the slab 104 has caused a cone-like fracture. As shown in the drawing, the inventors of the present application are that the headed stud 115 ruptured by the force test is the center portion of the span of the length L of the steel beam 103 (the center 2/4 section when the span is divided into four equal parts). Therefore, the inventors found that the breakage of the headed stud 115 is caused by the axial displacement of the steel beam 103 with respect to the slab 104, and the present invention has been conceived.

FIG. 14 is a graph in which the relative displacement displacement δ _s in the material axis direction between the slab 104 and the upper flange of the steel beam 103 shown in FIG. 12 is shown on the horizontal axis, and the shearing force Q is shown on the vertical axis. It is. In FIG. 14, the solid line indicates the relative displacement δ _s at the center of the steel beam 103, and the broken line and the alternate long and short dash line indicate the relative displacement δ _s at the east and west ends of the steel beam 103. From the graph, the relative displacement displacement [delta] _s of the steel beam middle portion, it can be seen that greater than the relative displacement displacement [delta] _s of steel beam end. From this, it is considered that the headed stud 115 breaks due to the relative displacement in the axial direction of the steel beam 103 with respect to the slab 104.

  In order to solve the above-described problems, an aspect of the present invention is a steel beam lateral stiffening structure, and includes an upper flange (6), a lower flange (7), and a web connecting the upper flange and the lower flange. A steel beam (3) having (8), a reinforced concrete slab (4) provided on the steel beam, and extending in a direction (X direction) perpendicular to the axial direction (Y direction) of the steel beam. And a plurality of perforated steel plate gibbels (10) embedded in the slab and bonded to the upper surface of the upper flange.

  The perforated steel plate gibel joined to the upper surface of the upper flange so as to extend in the direction perpendicular to the axial direction of the steel beam, that is, the out-of-plane direction of the steel beam, is the in-plane direction (out-of-plane direction of the steel beam). While having high rigidity, it has low rigidity in the out-of-plane direction (in-plane direction of the steel beam). Therefore, according to this configuration, the steel beam is joined to the slab with a high restraining force by the perforated steel plate gibel in the out-of-plane direction, and joined to the slab in the in-plane direction to allow relative displacement. . Thereby, the breakage of the perforated steel plate gibel is prevented, and the lateral complementary rigidity ability by the slab is improved. Moreover, the increase in the amount of steel frames and the increase in labor for processing steel beams can be suppressed.

  Further, in the above configuration, when the span (L) of the steel beam (3) is divided into four equal sections, and a 2/4 section located on the center side is set as a central section, the steel beam (3) A plurality of the perforated steel plate dowels (10) may be provided in the portion (3a) corresponding to the central section.

  According to this configuration, the portion corresponding to the central section of the steel beam having a large axial displacement relative to the slab is joined to the slab with a low restraining force. Thereby, the lateral complementary rigidity ability by the slab is effectively improved by preventing breakage of the dowel.

  Further, in the above configuration, when the span (L) of the steel beam (3) is divided into four equal sections, and the quarter sections located at both ends are used as end sections, the front steel frame It is preferable to further include a plurality of headed studs (15) joined to the upper surfaces of both portions (3b) corresponding to the end sections of the beam and embedded in the slab (4).

  Compared to perforated steel plate gibbels, headed studs can be easily joined to steel beams. Further, in the portion corresponding to the end section of the steel beam, the axial displacement of the steel beam relative to the slab is small. Therefore, according to this configuration, by providing the headed stud in the end section of the steel beam, it is possible to reduce the number of perforated steel plate gibbles and reduce the processing effort of the steel beam.

  Moreover, in the said structure, it provided along the axial direction (Y direction) of the said steel beam (3) so that the hole (11) of the said perforated steel plate gibble (10) might be penetrated, and it embed | buried in the said slab (4) It is good to further provide the 1st reinforcing bar (12) made.

  According to this configuration, the restraining force in the in-plane direction (out-of-plane direction of the steel beam) of the perforated steel plate dowel by the slab can be improved with a simple configuration.

  Moreover, the said structure WHEREIN: It is good to further provide the 2nd reinforcement bar (19) provided along the said headed stud (15) and embed | buried under the said slab (4).

  According to this configuration, the restraining force of the headed stud in the out-of-plane direction of the steel beam due to the slab can be improved with a simple configuration. Moreover, the cone-shaped destruction of the part by which the stud with the head of the slab was embed | buried can be suppressed.

  Further, in the above configuration, the steel beam (3) is provided on both the left and right sides of the web (8) to connect at least one pair of stiffeners (6) and the lower flange (7). 9), and the perforated steel plate dowel (10) may be disposed at a position aligned with the stiffener in the axial direction (Y direction) of the steel beam.

  According to this configuration, the steel beam is locally deformed at the position where the perforated steel plate dowel is provided, and the steel beam is restrained from being laterally buckled.

  Moreover, the said structure WHEREIN: It is good for the said perforated steel plate gibber (10) to be joined to the said upper flange (6) by groove welding.

  According to this structure, it is suppressed that the rigidity of the out-of-plane direction (in-plane direction of a steel beam) of a perforated steel plate gibel is improved by welding. This prevents breakage of the perforated steel plate dowel.

  As described above, according to the present invention, it is possible to provide a lateral stiffening structure for a steel beam that can suppress an increase in the amount of steel frame and an increase in processing time of the steel beam and can be easily constructed.

Schematic plan view of a building to which the lateral stiffening structure according to the first embodiment is applied II-II sectional view in FIG. III-III sectional view in FIG. IV-IV sectional view in Fig. 2 VV sectional view in FIG. Sectional drawing corresponding to FIG. 3 of the lateral stiffening structure which concerns on a 1st modification Sectional drawing corresponding to FIG. 3 of the lateral stiffening structure which concerns on a 2nd modification Sectional drawing corresponding to FIG. 3 of the lateral stiffening structure which concerns on a 3rd modification Sectional drawing corresponding to FIG. 4 of the lateral stiffening structure which concerns on a 4th modification Sectional drawing corresponding to FIG. 4 of the horizontal stiffening structure which concerns on a 5th modification Sectional drawing corresponding to FIG. 4 of the lateral stiffening structure which concerns on a 6th modification Side view of test equipment for composite steel beam specimen Plan view showing damage condition of specimen of composite steel beam after loading test Graph showing the relative displacement displacement in the axial direction between the slab of the composite steel beam and the upper flange of the steel beam

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic plan view of a building 1 to which a lateral stiffening structure according to the present invention is applied. As shown in FIG. 1, the building 1 has a plurality of pillars 2 arranged in the X direction and the Y direction orthogonal to each other in plan view. The column 2 may be a steel frame structure or a steel frame reinforced concrete structure. Between each pair of pillars 2 adjacent to each other in the X direction and the Y direction, steel beams 3 whose both ends are joined to the pair of pillars 2 are bridged for each layer. The interval between the columns 2 is longer in the Y direction than in the X direction, and the steel beam 3 extending in the Y direction is longer than the steel beam 3 extending in the X direction.

  2 is a cross-sectional view taken along the line II-II in FIG. 1 and is a vertical cross-sectional view showing the steel beam 3 along the in-plane direction. As shown in FIG. 2, a slab 4 made of reinforced concrete is constructed on the steel beam 3 on each floor. The slab 4 is made of reinforced concrete formed by cast-in-place concrete 5 and includes a reinforcing bar composed of a plurality of main reinforcing bars extending in the X direction and a plurality of reinforcing bars extending in the Y direction. The slab 4 may be a double bar arrangement including a lower end bar and an upper end bar composed of a main bar and a bar arrangement bar, respectively, or may be a single bar arrangement.

  In FIG. 2, the reinforcing bars of the slab 4 are not shown. In FIG. 2, although the concrete 5 is hatched, members that do not appear in the cross section are shown as seen through the concrete 5. The same applies to FIGS. 3 to 5 described below.

  The slab 4 in the illustrated example is constructed using a removed formwork not shown, and the concrete 5 is exposed on the lower surface. In another example, the concrete 5 of the slab 4 may be placed using a deck plate, and the slab 4 may include a deck plate constructed integrally with the deck plate.

  The steel beam 3 is spanned between a pair of columns 2 arranged with a pitch (inter-center distance) of length L in the Y direction, and has a span of length L. Here, the span of the steel beam 3 is divided into four equal sections, each 1/4 section located at both ends is defined as an end section, and 2/4 sections located at the center are defined as a center section. . Hereinafter, a portion corresponding to the central section of the steel beam 3 is referred to as a steel beam central portion 3a, and a portion corresponding to the end section of the steel beam 3 is referred to as a steel beam end portion 3b.

  3 is a cross-sectional view taken along the line III-III in FIG. 2, and is a cross-sectional view showing the steel beam central portion 3a along the out-of-plane direction. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2, and is a cross-sectional view showing the steel beam end 3b along the out-of-plane direction. As shown in FIGS. 2 to 4, the steel beam 3 is made of I-shaped steel and has an upper flange 6, a lower flange 7, and a web 8 that connects the upper flange 6 and the lower flange 7. . Stiffeners 9 are provided at predetermined positions in the axial direction of the steel beam 3 so as to connect the upper flange 6, the lower flange 7, and the web 8 to each other on the left and right sides of the web 8. The left and right stiffeners 9 have the same shape and are welded to the corresponding side surface of the web 8, the lower surface of the upper flange 6, and the upper surface of the lower flange 7, respectively.

  As shown in FIGS. 2 and 3, a plurality of perforated steel plate gibels 10 are joined to the upper surface of the upper flange 6 of the steel beam central portion 3 a so as to extend in the out-of-plane direction of the steel beam 3. . The plurality of perforated steel plate gibbels 10 are provided only in the steel beam beam central portion 3 a with a space in the direction of the material axis of the steel beam 3. In the present embodiment, three perforated steel plate gibels 10 are provided at three locations, the center of the span of the steel beam 3 and both sides in the material axis direction. The left and right stiffeners 9 are arranged at positions aligned with the perforated steel plate gibber 10 in the axial direction of the steel beam 3.

  The perforated steel plate gibber 10 is made of a steel plate (flat steel) in which at least one through hole 11 is formed. In the present embodiment, the perforated steel plate diver 10 has a rectangular shape having a length (the length in the out-of-plane direction of the steel beam 3 and the length in the in-plane direction of the perforated steel plate gibel 10) compared to the height. It has two circular cross-sectional through-holes 11 made of a steel plate and spaced apart in the length direction. The perforated steel plate gibber 10 has a height smaller than the thickness of the slab 4 and is embedded in the concrete 5 of the slab 4 so as not to be exposed.

  FIG. 5 is a cross-sectional view taken along the line VV in FIG. 3 and corresponds to a partially enlarged view of FIG. As shown in FIGS. 3 and 5, the first reinforcing reinforcing bars 12 extending in the out-of-plane direction (the axial direction of the steel beam 3) of the perforated steel plate gibel 10 are provided in the through holes 11 of the perforated steel plate gibel 10. Is provided so as to penetrate the through hole 11 and embedded in the concrete 5. The first reinforcing reinforcing bars 12 are arranged in addition to the reinforcing bars of the slab 4, and may be round steel bars or different diameter steel bars. In the example of FIG. 5, a relatively short first reinforcing bar 12 is provided for each perforated steel plate diver 10, but the relatively long first reinforcing bars 12 are bridged between adjacent perforated steel plate gibels 10. It may be provided as follows. By setting it as such a form, when the space | interval of the perforated steel plate dowel 10 adjacent to each other is short, arrangement | positioning of the 1st reinforcement bar 12 becomes easy.

  As shown in FIG. 5, the perforated steel plate gibber 10 has a groove formed at the lower edge, and is joined to the upper surface of the upper flange 6 of the steel beam 3 by groove welding. In the illustrated example, a K-shaped groove is formed at the lower edge of the perforated steel plate diver 10, and the perforated steel plate diver 10 is joined to the upper flange 6 by welding (blacked portions) from both sides in the out-of-plane direction. . In another example, a re-shaped groove may be formed at the lower edge of the perforated steel plate diver 10, and the perforated steel plate divel 10 may be joined to the upper flange 6 by welding from one side of the surface in the out-of-plane direction. Alternatively, a J-shaped or double-sided J-shaped groove may be formed at the lower edge of the perforated steel plate gibber 10.

  As shown in FIGS. 2 and 4, a plurality of headed studs 15 are implanted on the upper surface of the upper flange 6 of the steel beam end 3b. The plurality of headed studs 15 are provided only in the steel beam end portion 3b with a gap in the material axis direction of the steel beam 3. In this embodiment, six head studs 15 in total for each of the steel beam end portions 3b, a total of twelve headed studs 15, are located in the center of the upper flange 6 in the left-right direction, that is, directly above the web 8 in the direction of the axis of the steel beam 3. It is provided in one row with equal intervals.

  The headed stud 15 has a shaft portion 16 that protrudes upward from the upper surface of the upper flange 6, and a head portion 17 that increases in diameter at the tip of the shaft portion 16. The headed stud 15 is fixed to the upper flange 6 by stud welding the base end of the shaft portion 16 to the upper surface of the upper flange 6, and is embedded in the concrete 5 of the slab 4 so as not to be exposed. The shaft portion 16 extends vertically so as to be orthogonal to the upper flange 6, and the head portion 17 is formed in a disk shape or a columnar shape coaxially with the shaft portion 16. The lower surface of the head 17 is formed in an annular and horizontal manner around the shaft portion 16, and the conical surface indicated by a broken line extending outward from the periphery of the lower surface of the head 17 at an angle of 45 degrees is a cone-shaped fracture surface. 18

  Two second reinforcing bars extending in the axial direction of the steel beam 3 along the headed stud 15 are located on the left and right sides of the headed stud 15 and at a position intersecting the cone fracture surface of the headed stud 15. 19 is provided. The second reinforcing steel bars 19 are arranged in addition to the steel bars of the slab 4, and may be round steel bars or different diameter steel bars. The second reinforcing steel bars 19 may be disposed directly below the head 17 (positions in contact with the shaft portion 16), or may be disposed at positions offset laterally with respect to the head 17. In addition, the second reinforcing reinforcing bar 19 may be arranged directly below the head 17 (position in contact with the head 17), or may be arranged at a position lower than the head 17.

  The slab 4 is made of a perforated steel plate by placing concrete 5 on the upper flange 6 so as to embed the perforated steel plate gibble 10, the first reinforcing bar 12, the headed stud 15 and the second reinforcing bar 19. It is integrated with the steel beam 3 via the gibber 10 and the headed stud 15.

  Since the slab 4 and the steel beam 3 are combined in this way, the rigidity against the lateral force of the steel beam 3 is increased, and the proof strength against the lateral buckling of the steel beam 3 is improved. That is, at the time of an earthquake, the steel beam 3 is likely to be laterally buckled by elastically deforming both ends of the steel beam 3 in the portion of the elastic-plastic region before both ends of the steel beam 3 reach the fully plastic state. Lateral buckling of the steel beam 3 is less likely to occur as the bonding strength of the steel beam 3 to the slab 4 is higher.

  When the tensile strength of the headed stud 15 is sufficiently high, the joint strength is determined by the load at which the concrete 5 causes a cone-like fracture due to the tension of the headed stud 15. In the present embodiment, the steel beam end portion 3b is provided with more than the number of headed studs 15 that can secure a sufficient bonding strength to the slab 4, thereby restraining the rotational deformation of the steel beam end portion 3b. Torsional rigidity is given.

  On the other hand, a perforated steel plate dowel 10 is provided at the steel beam central portion 3a, and the perforated steel plate dowel 10 is headed in the in-plane direction (vertical direction and the out-of-plane direction (left-right direction) of the steel beam 3). Compared to the stud 15, the joint strength is several times greater. Therefore, a torsional rigidity that restrains the rotational deformation of the steel beam central portion 3a is given by a small number of perforated steel plate gibbels 10 as compared with the case where the headed stud 15 is provided.

Further, in the composite beam in which the slab 4 is attached to the steel beam 3, relative displacement occurs in the material axis direction of the steel beam 3 between the steel beam 3 and the slab 4 due to the force applied during the earthquake. This relative displacement displacement [delta] _s, as described with reference to FIG. 14, greater than the steel beam end 3b in the steel beam middle portion 3a. Therefore, even if the bonding strength to the slab 4 is sufficient, when the headed stud 15 is provided in the steel beam central portion 3a, the headed stud 15 is broken by the shearing force Q that causes this relative deviation. .

  On the other hand, in the steel beam lateral stiffening structure of the present embodiment, the following operational effects are exhibited.

The headed stud 15 is not provided in the steel beam central portion 3a, and a perforated steel plate gibber 10 is provided instead. The perforated steel plate gibber 10 has a characteristic that the rigidity in the in-plane direction is high while the rigidity in the out-of-plane direction is low. In other words, the perforated steel plate dowel 10 absorbs the relative displacement δ _s in the in-plane direction (material axis direction) of the steel beam 3 by deformation without impairing the restraining force in the out-of-plane direction of the steel beam 3. As described above, in this embodiment, the steel beam central portion 3a is joined to the slab 4 with a high restraining force by the perforated steel plate gibel 10 in the out-of-plane direction, and relative displacement is allowed in the in-plane direction. Are joined to the slab 4. Thereby, the fracture | rupture of the perforated steel plate dowel 10 is prevented, and the lateral complementary rigidity ability by the slab 4 is improved. Further, since it is not necessary to provide a lateral buckling stiffener such as a small beam or a cane, an increase in the amount of steel frames and an increase in labor for processing the steel beam 3 are suppressed.

  Since a plurality of perforated steel plate gibels 10 are provided in the steel beam central portion 3a corresponding to the central section of the steel beam 3, the portion corresponding to the central section of the steel beam 3 having a large axial displacement with respect to the slab 4 is low. Joined to the slab 4 with restraining force. As a result, the lateral supplementary rigidity by the slab 4 is effectively improved by preventing the breakage of the dowel.

  A plurality of headed studs 15 embedded in the slab 4 are joined to the upper surfaces of both steel beam end portions 3 b corresponding to the end sections of the steel beam 3. The headed stud 15 can be easily joined to the steel beam 3 as compared with the perforated steel plate gibber 10. Further, in the portion corresponding to the end section of the steel beam 3, the axial displacement of the steel beam 3 relative to the slab 4 is small. Therefore, the number of necessary perforated steel plate gibbles 10 is reduced, and the processing effort of the steel beam 3 is reduced.

  Since the first reinforcing rebar 12 is provided along the axial direction of the steel beam 3 so as to pass through the hole of the perforated steel plate gibber 10 and embedded in the slab 4, the in-plane of the perforated steel plate diver 10 by the slab 4 The restraining force in the direction (out-of-plane direction of the steel beam 3) is improved by a simple configuration.

  Since the second reinforcing steel bars 19 are provided along the headed studs 15 and embedded in the slab 4, the restraining force of the headed studs 15 in the out-of-plane direction of the steel beam 3 by the slabs 4 is improved by a simple configuration. . Moreover, the cone-shaped destruction of the part by which the stud 15 with the head of the slab 4 was embed | buried is suppressed.

  Since the perforated steel plate dowel 10 is arranged at a position that aligns in the axial direction of the steel beam 3 with respect to the pair of stiffeners 9 provided on the left and right sides of the web 8, the perforated steel plate dowel 10 is provided. It is suppressed that the steel beam 3 is locally deformed at the position and the steel beam 3 is laterally buckled.

  Since the perforated steel plate gibel 10 is joined to the upper flange 6 by groove welding, it is suppressed that the rigidity in the out-of-plane direction (in-plane direction of the steel beam 3) of the perforated steel plate gibel 10 is improved by welding. . Thereby, the fracture | rupture of the perforated steel plate dowel 10 is prevented.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified.

  For example, in the said embodiment, as FIG.3 and FIG.5 shows, although the 1st reinforcement bar 12 is provided along the axial direction of the steel beam 3 so that the hole of the perforated steel plate gibber 10 may be penetrated. As shown in FIG. 6, the first reinforcing reinforcing bars 12 may not be provided. Moreover, in the said embodiment, although the groove | channel was formed in the lower edge of the perforated steel plate dowel 10, as shown in FIG. The lower edge may be joined to the upper flange 6 of the steel beam 3 by fillet welding.

  In the above embodiment, the perforated steel plate gibber 10 is made of flat steel, but as shown in FIG. 8, the perforated steel plate gibber 10 may be made of angle steel 20 (L-shaped steel, angle). In the example of FIG. 8, a perforated steel plate gibber 10 is formed from equilateral angle steel. In another example, the perforated steel plate dowel 10 may be formed from unequal angle iron. The angle steel 20 has a first side 20 a extending along the upper flange 6 of the steel beam 3 and a second side 20 b extending perpendicular to the upper flange 6. The angle steel 20 is fillet welded to the upper surface of the upper flange 6 at the front edge and the rear edge (four corners, etc.) of the first side 20a while extending in the out-of-plane direction of the steel beam 3. 3 is joined. The through-hole 11 is formed in the 2nd edge | side 20b of the angle iron 20, and the steel plate dowel 10 is formed of the 2nd edge | side 20b.

  Alternatively, as shown in FIG. 9, the perforated steel plate gibber 10 may be formed from a CT section steel 21. The CT section 21 has a first side 21a that forms a flange portion that extends along the upper flange 6 of the steel beam 3 and a second portion that forms a web portion that extends vertically from the center of the first side 21a. Side 21b. The CT shape steel 21 is formed by welding the front edge and the rear edge (four corners, etc.) of the first side 20a to the upper surface of the upper flange 6 while extending in the out-of-plane direction of the steel beam 3. Joined to the beam 3. The through-hole 11 is formed in the 2nd edge | side 21b of CT shape steel 21, and the steel plate dowel 10 is formed of the 2nd edge | side 21b.

  In the above embodiment, any of the perforated steel plate dowels 10 is formed to have a length shorter than the width B of the steel beam 3 (the dimension in the out-of-plane direction of the steel beam 3). On the other hand, as shown in FIG. 10, even if the perforated steel plate gibber 10 or a steel material (an angle steel 20 or a CT steel 21 or the like) forming the perforated steel plate is formed to have a length L longer than the width B of the steel beam 3. Good. In this case, the length L of the perforated steel plate gibber 10 is preferably about 1 to 3 times the width B of the steel beam 3. In this case, more through holes 11 may be formed in the perforated steel plate dowel 10 than in the above embodiment. Thereby, the steel beam 3 is joined to the slab 4 with a higher restraining force by the perforated steel plate gibber 10 in the out-of-plane direction.

  In the above embodiment, as shown in FIG. 4, a plurality of headed studs 15 are arranged in one row at the center in the left-right direction of the upper flange 6, but as shown in FIG. The headed studs 15 may be provided in two rows on both the left and right sides sandwiching the web 8 of the upper flange 6. In this case, the second reinforcing bars 19 may be provided on the left and right sides of each row of headed studs 15 as illustrated, or may be provided only on the outside of the two rows of headed studs 15. Or even if it is a case where the stud 15 with a head is arrange | positioned at 1 row, or it is a case where it is arrange | positioned at 2 rows, the 2nd reinforcement bar 19 does not need to be provided. Alternatively, the first reinforcing bar 12 and the second reinforcing bar 19 may be a common reinforcing bar or a reinforcing bar that is joined together.

  In addition, the specific configuration, arrangement, quantity, angle, and the like of each member and part can be changed as appropriate without departing from the spirit of the present invention. In addition, a part of the configuration of the above embodiment may be appropriately combined or appropriately discarded. Furthermore, all the constituent elements shown in the above embodiment are not necessarily essential, and can be appropriately selected.

DESCRIPTION OF SYMBOLS 1 Building 2 Column 3 Steel beam 4 Slab 5 Concrete 6 Upper flange 7 Lower flange 8 Web 9 Stiffener 10 Perforated steel plate gibber 11 Through hole 12 1st reinforcing bar 15 Headed stud 19 2nd reinforcing bar

Claims (7)

A steel beam having an upper flange, a lower flange, and a web connecting the upper flange and the lower flange;
A slab made of reinforced concrete provided on the steel beam;
A steel beam lateral stiffening comprising: a plurality of perforated steel plate gibbles that are joined to the upper surface of the upper flange so as to extend in a direction perpendicular to the axial direction of the steel beam and embedded in the slab. Construction.   When the span of the steel beam is divided into four equal sections, and a 2/4 section located on the center side is defined as a central section, a plurality of the perforations are formed in a portion corresponding to the central section of the steel beam. The steel beam lateral stiffening structure according to claim 1, wherein a steel plate gibber is provided.   When the span of the steel beam is divided into four equal sections, and the quarter sections located at both ends are used as end sections, the upper surfaces of both portions corresponding to the end sections of the steel beam The steel beam lateral stiffening structure according to claim 2, further comprising a plurality of headed studs bonded to each other and embedded in the slab.   The first reinforcing steel bar further provided in the axial direction of the steel beam so as to penetrate the hole of the perforated steel plate gibber and embedded in the slab. The steel beam transverse stiffening structure according to any one of the above.   The steel beam lateral stiffening structure according to claim 3, further comprising a second reinforcing steel bar provided along the headed stud and embedded in the slab. The steel beam further has at least one pair of stiffeners provided on both the left and right sides of the web to connect the upper flange and the lower flange;
The steel beam lateral stiffening structure according to any one of claims 1 to 5, wherein the perforated steel plate gibel is disposed at a position aligned with the stiffener in an axial direction of the steel beam.   The steel beam lateral stiffening structure according to claim 1 or 2, wherein the perforated steel plate gibel is joined to the upper flange by groove welding.

Images