JP7366782B2 - floor structure - Google Patents

Description

The present invention relates to a floor structure that supports the ends of a floor slab on the upper surface of a steel beam via studs.

A floor structure including a concrete floor slab installed on the upper surface of a steel beam (H-shaped steel) is known (Patent Document 1). Concrete floor slabs are connected to steel beams by headed studs.

Japanese Patent Application Publication No. 2015-21283

In the above floor structure, the steel beams installed around the outer periphery of the floor slab support the ends of the floor slab. In other words, this floor slab extends only on one side (inside) from the steel beam (hereinafter, such a floor slab will be referred to as a "one-sided slab"). In a steel beam (H-shaped steel) that supports a slab on one side, a large external force such as an earthquake may cause lateral buckling in which the upper part of the steel beam is displaced outward horizontally or around an axis. If lateral buckling occurs in the steel beam, the studs connected to the steel beam will also be displaced horizontally or around an axis outward. In one-sided slabs, the distance from the axis of the stud to the end face (outer edge) of the floor slab is short, so when the stud is displaced outward, a cone-shaped fracture occurs in the floor slab (concrete) around the stud, causing the stud to break into the floor slab. There were times when I got out of it.

In order to solve the above problems, the present invention provides a floor structure that can suppress lateral buckling of steel beams to which ends of floor slabs are connected.

The floor structure of the present invention includes a steel beam extending in the axial direction, a stud erected on the upper surface of the steel beam, and an end portion of the steel beam embedded in the stud and intersecting in the axial direction. A floor slab supported on the upper surface of the beam, and a reinforcing member buried in the floor slab, the reinforcing member being disposed below the top end of the stud, and being closer to the intersection of the floor slab than the stud. a first reinforcing bar extending along the axial direction on the end side of the direction; and a first reinforcing bar disposed below the top end of the stud, extending along the intersecting direction, and engaging the first reinforcing bar. and a second reinforcing bar.

In this case, the second reinforcing bar may have a bent portion that is bent at the end in the intersecting direction and intersects with the first reinforcing bar.

In this case, the second reinforcing bars include upper reinforcing bars extending in the crossing direction above the first reinforcing bars, and lower reinforcing bars extending in the crossing direction below the first reinforcing bars. and a bent portion connecting the ends of the upper reinforcing bar and the lower reinforcing bar in the crossing direction, and at least the lower reinforcing bar is disposed below the top end of the stud, and 1 reinforcing bar may be arranged inside the bent portion.

In this case, the installation range of the reinforcing member is preferably 25% or more of the length of the steel beam in the axial direction from one end of the steel beam in the axial direction to the other end.

In this case, the steel beam is configured by connecting a plurality of steel frames with a joint member, the stud and the second reinforcing bar are provided at a position avoiding the joint member, and the installation range of the reinforcing member is: The length from one end of the steel beam to the other end in the axial direction is preferably at least 25% of the length of the steel beam in the axial direction plus the length of the joint member in the axial direction.

In this case, the second reinforcing bar arranged at the end in the axial direction may be connected to the end in the axial direction of the first reinforcing bar via a curved portion.

According to the present invention, it is possible to suppress lateral buckling of a steel beam to which the ends of a floor slab are connected.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows a part of building provided with the floor structure based on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows a part of building provided with the floor structure based on 1st Embodiment of this invention. It is a top view showing a part of floor structure concerning a 1st embodiment of the present invention. 4 is a sectional view taken along line IV-IV in FIG. 3. FIG. FIG. 1 is a plan view showing a part of the floor structure (excluding the floor slab) according to the first embodiment of the present invention. It is a sectional view showing a part of floor structure concerning a 2nd embodiment of the present invention. It is a top view which shows a part of floor structure (excluding a floor slab) based on 3rd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that in this specification, an orthogonal coordinate system in a three-dimensional space in which the X direction, Y direction, and Z direction (vertical direction) are orthogonal to each other is used to indicate directions. Although terms indicating directions and positions are used in this specification, these terms are used for convenience of explanation and do not limit the technical scope of the present invention.

[First embodiment]
First, a building 100 including a floor structure 1 will be briefly described with reference to FIGS. 1 and 2. FIG. 1 is a plan view showing a part of a building 100 including a floor structure 1. As shown in FIG. FIG. 2 is a perspective view showing a part of the building 100 including the floor structure 1. As shown in FIG.

The building 100 has a plurality of (four in FIG. 1) steel columns 101 erected at positions spaced apart in the XY direction. Steel beams 10 are constructed for each floor between adjacent steel columns 101 in the XY direction. Both ends of the steel beam 10 in the axial direction are fixed to the steel column 101 by welding, bolts, or the like. Two small beams 102 are constructed between a pair of steel beams 10 spaced apart in the Y direction. Both ends of the small beam 102 in the axial direction are fixed to the steel beam 10 by welding, bolts, or the like. Ends of reinforced concrete floor slabs 12 are supported on the upper surfaces of four steel beams 10 on each floor, forming a floor structure 1. Note that the pillars of the building 100 are not limited to the steel-framed steel-framed columns 101, and may be, for example, reinforced concrete construction, steel-framed reinforced concrete construction, or concrete-filled steel pipe construction.

[Floor structure]
A one-level floor structure 1 will be described with reference to FIGS. 1 to 5. FIG. 3 is a plan view showing a part of the floor structure 1. FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG. 5 is a plan view showing a part of the floor structure 1 (excluding the floor slab 12).

As shown in FIGS. 1 and 3, the floor structure 1 includes a plurality of (four in FIG. 1) steel beams 10, a plurality of studs 11, a floor slab 12, and a plurality of reinforcing members 15. There is. Note that this specification focuses on one steel beam 10 that is placed on one side of the X direction (on the right side in FIG. 1) and extends in the Y direction (axial direction), and the structure around it. explain. In addition, since the structure around each steel column 101 is substantially the same, in this specification, the structure around one steel column 101 (one side in the axial direction of the steel beam 10 (upper side in FIG. 1)) will be described. I will focus on and explain.

<Steel beam>
As shown in FIG. 2, the steel beam 10 is an H-beam with an upper flange 10A and a lower flange 10B connected by a web 10C. In addition, the steel beam 10 is not limited to H-beam steel, and may be, for example, I-beam steel.

<Stud>
As shown in FIGS. 3 and 4, the plurality of studs 11 are erected on the upper surface of the steel beam 10. Each stud 11 is a headed stud having a shaft portion 11A extending in the vertical direction and a head portion 11B having an enlarged diameter at the upper end of the shaft portion 11A. The shaft portion 11A is formed into a rod shape with a circular cross section, and the head portion 11B is formed into a disk shape fixed coaxially with the shaft portion 11A. The stud 11 is fixed to the upper flange 10A by welding the lower end of the shaft portion 11A to the upper surface of the upper flange 10A. The plurality of studs 11 are arranged in parallel at intervals in the axial direction of the steel beam 10 (Y direction in FIG. 3) to form a row, and the row formed by the plurality of studs 11 is arranged in the axial direction of the steel beam 10 (Y direction in FIG. 3). Two rows are provided at intervals in the cross direction (X direction in FIG. 3) perpendicular to the . That is, the plurality of studs 11 are arranged in two rows on both sides of the upper flange 10A with the web 10C in between, and are arranged in a grid pattern when viewed from above.

<Floor slab>
As shown in FIGS. 3 and 4, the floor slab 12 is made of reinforced concrete in which slab reinforcements 13 are embedded in concrete. For example, two slab lines 13 are arranged vertically apart from each other in the floor slab 12 (see FIG. 4). The slab reinforcement 13 includes a plurality of first reinforcing bars 13A extending in the Y direction and a plurality of second reinforcing bars 13B extending in the X direction. That is, the slab lines 13 are formed in a lattice shape when viewed from above (see FIG. 3). The plurality of second reinforcing bars 13B are arranged at positions corresponding to the studs 11, respectively. The first and second reinforcing bars 13A and 13B are deformed reinforcing bars, and the intersection portions of the first and second reinforcing bars 13A and 13B are tied together with a binding wire or the like (or may be welded).

Furthermore, the floor slab 12 is supported by the upper surface of the steel beam 10 at its end in the X direction (crossing direction) with studs 11 embedded therein. Although not shown, the end of the floor slab 12 in the Y direction is also supported by the upper surface of the steel beam 10 with studs 11 embedded therein.

The end of the floor slab 12 extends outward from the upper flange 10A of the steel beam 10. The floor slab 12 is a one-sided slab that extends largely in one direction in which the steel beams 10 intersect. In this specification, the end of the floor slab 12 does not refer only to the vicinity of the end surface of the floor slab 12, but refers to a certain range extending inward from the end surface of the floor slab 12. The certain range refers to a range wider than the width of the steel beam 10 in the cross direction, for example. For example, it is preferable that the dimension Lh between the axis of the studs 11 in the outer row (on the end side of the floor slab 12) and the end surface of the floor slab 12 is set to 100 mm or more (see FIG. 4).

<Reinforcement member>
As shown in FIGS. 3 and 4, the reinforcing member 15, like the studs 11 and slab reinforcements 13, is embedded in the floor slab 12 (concrete). Note that four reinforcing members 15 are provided around the four steel columns 101, but as mentioned earlier, the explanation will focus on one reinforcing member 15 around one steel column 101. .

As shown in FIGS. 3 to 5, the reinforcing member 15 includes first reinforcing bars 21 and a plurality of second reinforcing bars 22. As shown in FIGS. The first and second reinforcing bars 21 and 22 are deformed reinforcing bars with the same diameter. Note that in FIG. 5, illustration of the floor slab 12 is omitted in order to clearly show the reinforcing member 15. Moreover, to be more precise, the first reinforcing bars 21 are divided into a plurality of pieces in consideration of transportation to the construction site and ease of construction work, and are spliced together at the construction site.

(1st reinforcement)
The first reinforcing bar 21 is arranged below the top end of the stud 11 (see FIG. 4). Specifically, the first reinforcing bars 21 are arranged below the head 11B when viewed from the side. Further, the first reinforcing bars 21 extend along the axial direction outside the studs 11 in the X direction (on the end side of the floor slab 12 in the cross direction) (see FIGS. 3 to 5). Specifically, the first reinforcing bars 21 are spaced apart from the studs 11 in the outer row in the X direction.

(Second reinforcement)
The second reinforcing bars 22 are arranged below the top end of the stud 11 and extend along the X direction (crossing direction) (see FIG. 4). Specifically, the top (uppermost part) of the second reinforcing bar 22 is arranged at approximately the same height as the top (upper surface) of the head 11B when viewed from the side. Further, the second reinforcing bars 22 are engaged with the first reinforcing bars 21. In detail, the second reinforcing bars 22 have a bent portion 22A that is bent at the end in the X direction (crossing direction) and intersects with the first reinforcing bars 21 (see FIG. 4). The bent portion 22A is formed by folding the end portion of the second reinforcing bar 22 downward approximately 180 degrees. The bent portion 22A is connected (or may be welded) to the first reinforcing bar 21 with a binding wire (not shown).

As shown in FIG. 3, the second reinforcing bars 22 are arranged between adjacent second reinforcing bars 13B. That is, the plurality of second reinforcing bars 13B and the plurality of second reinforcing bars 22 are alternately arranged in parallel in the axial direction (Y direction). In other words, the studs 11 are arranged in a range surrounded by the first reinforcing bars 21 and the adjacent second reinforcing bars 22.

Further, as shown in FIG. 5, the second reinforcing bars 22 arranged at the ends of the steel beams 10 in the axial direction (Y direction) (near the steel columns 101) are connected to the first reinforcing bars 22 via the curved curved portions 22B. The reinforcing bar 21 is connected to an end portion of the reinforcing bar 21 in the axial direction. That is, the second reinforcing bars 22 and the first reinforcing bars 21 arranged near the steel column 101 are formed into a substantially L-shape by bending one deformed reinforcing bar. The pair of L-shaped first reinforcing bars 21 are stacked on both sides of the linear first reinforcing bars 21 extending in the axial direction, and are joined by a binding wire or the like.

As shown in FIG. 5, the fixation length L2' of the second reinforcing bars 22 to the floor slab 12 is ensured to be equal to or greater than L2+5d (L2'≧L2+5d). Here, "L2" is set according to the "Reinforced Concrete Bar Arrangement Guidelines and Explanations" (hereinafter also referred to as "Construction Guidelines") published by the Architectural Institute of Japan. Moreover, "d" is a numerical value of the name of the second reinforcing bar 22. Further, the lap joint length L1 between the L-shaped first reinforcing bars 21 and the linear first reinforcing bars 21 is also set according to the above-described construction guidelines. For example, when SD345 is used as the first and second reinforcing bars 21 and 22 and the design standard strength Fc of concrete is set to 18 N/mm^2, L2=40d and L1=50d.

The reinforcing member 15 configured as described above is installed in a predetermined range from the steel column 101 toward the center of the steel beam 10 in the axial direction. Specifically, the installation range Ls of the reinforcing member 15 is set to be 25% or more of the axial length L (see FIG. 1) of the steel beam 10 from one end of the steel beam 10 to the other end in the axial direction. (Ls=0.25L).

Further, the required strength (yield strength) of the second reinforcing bar 22 (one piece) of the reinforcing member 15 is calculated by the following formula (1) according to the horizontal stiffening force at the maximum strength of the stud 11 in the installation range Ls. , is set so as to satisfy equation (2). The number of second reinforcing bars 22, etc. are set based on the required proof strength of the second reinforcing bars 22 calculated in this way.

In the floor structure 1 according to the first embodiment described above, the first reinforcing bars 21 extending in the axial direction of the steel beam 10 and the second reinforcing bars 22 extending in the cross direction of the steel beam 10 are located at the top of the stud 11. It was placed below. Further, the first reinforcing bars 21 are arranged outside the studs 11, and the second reinforcing bars 22 are engaged with the first reinforcing bars 21. According to this configuration, the first and second reinforcing bars 21 and 22 are arranged below the top end of the stud 11, so that the force in the direction of the stud 11 coming off from the floor slab 12 can be effectively resisted. Moreover, since the first and second reinforcing bars 21 and 22 are integrated with the concrete surrounding the stud 11, the floor slab 12 can be securely restrained on the upper surface of the steel beam 10. As a result, the pull-out strength of the stud 11 is improved, and lateral movement of the upper portion of the steel beam 10 is restricted, and lateral buckling of the steel beam 10 can be suppressed. As a result, cone-shaped fracture of the floor slab 12 (concrete) around the stud 11 can be suppressed. Furthermore, since the first reinforcing bars 21 and the second reinforcing bars 22 are arranged to intersect with each other, and the reinforcing members 15 are formed in a lattice shape, even if a crack occurs in the floor slab 12, the crack will be removed. Growth can be suppressed.

Moreover, according to the floor structure 1 according to the first embodiment, the first and second reinforcing bars 21 and 22 connected at the bending part 22A are integrated with the concrete, so that the steel beam 10 has a resistance against lateral buckling. can be increased.

Further, according to the floor structure 1 according to the first embodiment, by setting the installation range Ls to be a range of 0.25L from the steel column 101 toward the axial center of the steel beam 10, lateral buckling of the floor slab 12 can be prevented. It is possible to suppress a decrease in the yield strength of the steel beam 10 due to cone-shaped fracture or the like.

Further, according to the floor structure 1 according to the first embodiment, since the second reinforcing bars 22 arranged at the ends in the axial direction are formed integrally with the first reinforcing bars 21, the anchorage length with respect to the floor slab 12 is The first and second reinforcing bars 21 and 22 that ensure the length L2' can be easily arranged.

[Second embodiment]
Next, with reference to FIG. 6, a floor structure 2 (reinforcing member 16) according to a second embodiment will be described. FIG. 6 is a sectional view showing a part of the floor structure 2. As shown in FIG. In addition, in the following description, the same code|symbol is attached|subjected to the same structure as the floor structure 1 based on 1st Embodiment, and the same description as the floor structure 1 based on 1st Embodiment is abbreviate|omitted.

In the floor structure 1 according to the first embodiment, it is assumed that the space for arranging the second reinforcing bars 22 in the quantity that satisfies the required strength cannot be secured, for example, when the interval between the slab reinforcements 13 adjacent in the axial direction is narrow. Ru. Therefore, the second reinforcing bars 23 of the floor structure 2 according to the second embodiment are configured such that the number of second reinforcing bars 23 that satisfies the required proof strength can be arranged even when the intervals between the slab bars 13 are narrow.

The second reinforcing bar 23 is formed by folding one deformed reinforcing bar approximately in half. Specifically, the second reinforcing bars 23 include an upper reinforcing bar 23B extending in the cross direction above the first reinforcing bars 21, and a lower reinforcing bar 23B extending in the crossing direction below the first reinforcing bars 21. 23C, and a bent portion 23A that connects the ends of the upper reinforcing bars 23B and the lower reinforcing bars 23C in the cross direction.

The upper reinforcing bars 23B are arranged above the top end of the stud 11, and the lower reinforcing bars 23C are arranged below the top end of the stud 11. The upper reinforcing bars 23B and the lower reinforcing bars 23C are arranged substantially parallel to each other, and the interval between the upper reinforcing bars 23B and the lower reinforcing bars 23C is set to be sufficiently larger than the diameter of the first reinforcing bars 21 (for example, 3 times or more). has been done. The bent portion 23A is curved in a substantially U-shape, and the first reinforcing bars 21 are arranged inside the bent portion 23A. Note that the required proof strength of the second reinforcing bars 23 is calculated by the above-described formula (1), treating one set of the upper reinforcing bars 23B and the lower reinforcing bars 23C as one second reinforcing bar 23.

According to the floor structure 2 according to the second embodiment described above, since the upper reinforcing bars 23B and the lower reinforcing bars 23C form a pair to constitute the second reinforcing bars 23, the required proof strength of the second reinforcing bars 23 is The axial arrangement interval of the second reinforcing bars 23 can be increased while ensuring the same. Thereby, for example, even if the interval between slab reinforcements 13 adjacent to each other in the axial direction is narrow, it is possible to arrange the second reinforcing reinforcements 23 in a quantity that satisfies the required proof strength.

Note that in the floor structure 2 according to the second embodiment, the upper reinforcing bars 23B are arranged above the tops of the studs 11, but are not limited to this, and may be arranged below the tops of the studs 11. (not shown). That is, at least the lower reinforcing bars 23C among the pair of upper and lower reinforcing bars 23B and 23C need only be disposed below the top end of the stud 11.

Further, in the floor structure 2 according to the second embodiment, the bent portion 23A is curved in a U-shape, but the bending portion 23A is not limited to this, and may be bent in a U-shape (polygonal shape), for example. figure).

[Third embodiment]
Next, with reference to FIG. 7, a floor structure 3 (reinforcing member 17) according to a third embodiment will be described. FIG. 7 is a plan view showing a part of the floor structure 3 (excluding the floor slab 12). In addition, in the following description, the same code|symbol is attached|subjected to the same structure as the floor structure 1 based on 1st Embodiment, and the same description as the floor structure 1 based on 1st Embodiment is abbreviate|omitted. Further, in FIG. 7, illustration of the floor slab 12 is omitted.

The steel beam 10 is sometimes welded to the steel column 101 at a construction site (on-site construction), but the steel frame 10D, which is a part of the steel beam 10, is welded to the steel column 101 at a factory or the like, and the steel column 101 is welded to the steel column 101. Sometimes it is delivered and installed at a construction site (factory construction).

When constructed in a factory, the steel beam 10 is constructed by joining a steel frame 10D welded to the steel column 101 and another steel frame 10D with a joint member 25 such as a splice plate. Since the joint member 25 is fixed to the steel frame 10D on both sides by a plurality of bolts 26, the stud 11 cannot be erected on the joint member 25, but is installed at a position avoiding the joint member 25 (on the steel frame 10D). has been done. Further, in the floor structure 3, the second reinforcing bars 22 of the reinforcing member 17 are also provided at a position away from the joint member 25 (at a position where the stud 11 is provided).

Further, the first reinforcing bars 21 are separated (separated) approximately at the center of the joint member 25 in the axial direction. Further, a pair of second reinforcing bars 22 arranged on both sides of the steel beam 10 in the axial direction are connected to both ends of the first reinforcing bars 21 in the axial direction via the curved portion 22B. That is, the first and second reinforcing bars 21 and 22 formed in an L shape are arranged on both sides of the steel beam 10 in the axial direction.

Furthermore, the installation range Ls' of the reinforcing member 17 is determined by adding the axial length Lj of the joint member 25 to 25% of the axial length of the steel beam 10 from one axial end of the steel beam 10 to the other. (Ls'=0.25L+Lj). That is, since the second reinforcing bars 22 cannot be arranged on the joint member 25, the installation range Ls' of the reinforcing member 17 is expanded by the length of the joint member 25.

In the floor structure 3 according to the third embodiment, the second reinforcing bars 22 are arranged avoiding the joint member 25, and the installation range Ls' of the reinforcing member 17 is increased by the length of the joint member 25. According to this configuration, even if the steel beam 10 is configured by connecting a plurality of steel frames 10D with the joint members 25, lateral buckling of the steel beam 10 can be suppressed by the floor slab 12 in which the reinforcing members 17 are embedded. can.

Note that in the floor structures 1 and 3 according to the first and third embodiments, the bent portion 22A of the second reinforcing bar 22 is folded downward at 180 degrees (see FIG. 4); Not limited. The bending angle of the bending portion 22A may be 90 degrees or 135 degrees (not shown). Further, the bending portion 22A may be bent from the bottom to the top (not shown). Further, the bent portion 22A may be omitted and the end portion of the second reinforcing bar 22 may not be bent (not shown). Even in this case, the end portion of the second reinforcing bar 22 may be connected to the first reinforcing bar 21 with a binding wire or the like.

Note that in the floor structures 1 to 3 according to the first to third embodiments, the slab reinforcements 13 are arranged vertically in two layers (see FIG. 4), but the slab reinforcements 13 are not limited to this, and may be arranged in a single layer. Alternatively, three or more layers may be arranged (not shown).

Further, in the floor structures 1 to 3 according to the first to third embodiments, the studs 11 are headed studs, but the studs 11 are not limited to this, and can be connected to the upper flange 10A, and can be connected to the top studs in the same manner as headed studs. Any member that can transmit shear force may be used. Further, in the floor structures 1 to 3 according to the first to third embodiments, the plurality of studs 11 are arranged in two rows on the upper surface of the steel beam 10, but the present invention is not limited to this. The plurality of studs 11 may be arranged in one row on the upper surface of the steel beam 10, or may be arranged in three or more rows (not shown). Even in this case, the first reinforcing bars 21 are arranged outside the studs 11 constituting the outermost row.

Further, in the floor structures 1 to 3 according to the first to third embodiments, the floor slab 12 is made of reinforced concrete, but is not limited to this, and may be, for example, a composite deck floor slab containing reinforced concrete and a deck plate. (not shown).

Note that the description of the above embodiment shows one aspect of the floor structure according to the present invention, and the technical scope of the present invention is not limited to the above embodiment. The present invention may be variously changed, replaced, and modified without departing from the spirit of the technical idea, and the scope of the claims includes all embodiments that can be included within the scope of the technical idea.

1, 2, 3 Floor structure 10 Steel beam 11 Stud 12 Floor slab 15, 16, 17 Reinforcement member 21 First reinforcement 22 Second reinforcement 22B Curved part 22A, 23A Bent part 23B Upper reinforcement 23C Lower reinforcement 25 fitting parts

Claims (5)

A steel beam extending in the axial direction,
a stud erected on the upper surface of the steel beam;
a floor slab in which the studs are embedded and the ends in the axial direction are supported on the upper surface of the steel beam;
A reinforcing member embedded in the floor slab,
The reinforcing member is
a first reinforcing bar disposed below the top end of the stud and extending along the axial direction closer to the end of the floor slab in the intersecting direction than the stud;
a second reinforcing bar disposed below the top end of the stud, extending along the intersecting direction, and engaged with the first reinforcing bar ;
A floor structure characterized in that the second reinforcing bar arranged at the axial end is connected to the axial end of the first reinforcing bar via a curved part. 2. The floor structure according to claim 1, wherein the second reinforcing bar has a bent part at an end in the cross direction and is folded over the first reinforcing bar. The second reinforcing bar is
an upper reinforcing bar extending in the cross direction above the first reinforcing bar;
a lower reinforcing bar extending in the cross direction below the first reinforcing bar;
a bent part connecting the ends of the upper reinforcing bar and the lower reinforcing bar in the crossing direction;
At least the lower reinforcing bar is arranged below the top end of the stud,
The floor structure according to claim 1, wherein the first reinforcing bars are arranged inside the bent portion. Any one of claims 1 to 3, wherein the installation range of the reinforcing member is 25% or more of the length of the steel beam in the axial direction from one end of the steel beam in the axial direction to the other end. The floor structure according to item 1. The steel beam is configured by connecting a plurality of steel frames with a joint member,
The stud and the second reinforcing bar are provided at a position avoiding the joint member,
The installation range of the reinforcing member is the sum of 25% of the axial length of the steel beam and the axial length of the joint member from one axial end of the steel beam to the other. The floor structure according to any one of claims 1 to 3, characterized in that the floor structure is larger than or equal to 1.

Images