JP2025071679A - Building structure - Google Patents

Abstract

To provide skeleton structure of a building in which a concrete slab with a thickened part can be supported by a steel beam with a simple configuration.SOLUTION: The skeleton structure 1 of a building has several pieces of steel columns 10, a steel beam 20 bridged across steel columns 10 adjacent to each other, and a concrete slab 30 supported by the steel beam 20. The concrete slab 30 has a body part 31 placed on a part of an upper flange (upper wall) 22 of the steel beam 20, and a thickened part 32 that is integrally run to the body part 31 and is formed thicker than the body part 31 and in which the other part of the upper flange 22 of the steel beam 20 is embedded.SELECTED DRAWING: Figure 2

Description

The present invention relates to the framework structure of buildings.

For example, a known structural framework for a building such as an office building is a steel-frame structure that has multiple steel columns, steel beams spanning adjacent steel columns, and a concrete slab supported by the steel beams (see, for example, Patent Document 1).

In this type of steel frame structure, the steel beams are typically made of H-shaped steel, and the concrete slab is placed on the upper flange (top wall) of the steel beam and supported by the steel beam.

JP 2014-9502 A

In the framework structure of a building such as the one described above, if it is necessary to increase the strength of a portion of the concrete slab, for example by making part of the concrete slab a cantilever slab that protrudes outside the building, that portion of the concrete slab may be configured as a thickened portion that is thicker than other portions.

However, if part of the concrete slab is made into a thickened section, for example if the level of the top surface of the concrete slab is constant, the height or level of the bottom surface of the concrete slab in the thickened section will be lower than the height or level of the bottom surface of other parts, creating a step shape. This means that it will be necessary to fix height-raising materials such as angle irons to the steel beams to align the level of the thickened section with the other parts, which creates the problem of a complicated structure.

In particular, when part of a concrete slab is made into a cantilever slab, it is necessary to use padding materials to align the level of most of the concrete slab other than the cantilever slab, which increases the amount of padding materials used and the labor required to fix them.

The present invention was made in consideration of these problems, and its purpose is to provide a building framework structure that allows a concrete slab with thickened sections to be supported by steel beams with a simple configuration.

The building framework of the present invention is a building framework having a plurality of steel columns, steel beams spanning adjacent steel columns, and a concrete slab supported by the steel beams, characterized in that the concrete slab has a main body portion placed on a portion of the upper wall of the steel beam, and a thickened portion that is integrally connected to the main body portion and is formed to be thicker than the main body portion, and into which the other portion of the upper wall of the steel beam is embedded.

In the above-mentioned configuration of the framework structure of the building of the present invention, it is preferable that reinforcing steel bars are embedded inside the thickened portion above the steel beams and straddle the steel beams.

In the above-mentioned configuration of the framework structure of the building of the present invention, it is preferable that a portion of the thickened portion protrudes to the outside of the building to form a cantilever slab.

The present invention provides a building framework structure that allows a concrete slab with thickened sections to be supported by steel beams with a simple structure.

FIG. 2 is a plan view of a certain floor of a building having a framework structure according to one embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 1. 3 is a cross-sectional view taken along line BB in FIG. 2. 3 is a cross-sectional view taken along line CC in FIG. 2.

Below, we will explain in detail the structural frame 1 of a building according to an embodiment of the present invention (hereinafter, simply referred to as "structural frame 1") with reference to the drawings.

The skeleton structure 1 shown in Figures 1 and 2 is applied to a steel-framed building 100, such as an office building. In this embodiment, the building 100 has multiple floors, and the portion of the skeleton structure 1 shown in Figures 1 and 2 is in the upper floors of the building 100 above the ground floor.

Note that the building 100 is not limited to an office building with multiple floors.

The framework structure 1 has multiple steel columns 10, steel beams 20 spanning adjacent steel columns 10, and a concrete slab 30 supported by the steel beams 20.

The multiple steel columns 10 are each formed from a square steel pipe and are spaced apart from one another. The multiple steel columns 10 are not limited to square steel pipes, and may be formed from steel of other shapes, such as H-shaped steel.

The steel beams 20 are connected at one end to a steel column 10 and at the other end to another steel column 10, so that they are supported in a state of being spanned between adjacent steel columns 10. In this embodiment, the multiple steel beams 20 span between the steel columns 10 located at the outermost positions of the building 100 and the steel columns 10 located on the inside of the building 100 relative to the steel columns 10. Each of the multiple steel beams 20 is a main girder.

A part of each steel beam 20 may be formed with a joint 11 that is previously joined to the steel column 10 at a factory or the like. In this case, the diaphragm to be provided between the steel column 10 and the joint 11 may be, for example, a through diaphragm, an inner diaphragm, or the like, provided at an appropriate position depending on the size and thickness of the steel column 10, the steel beam 20, and the concrete slab 30.

In this embodiment, each of the multiple steel beams 20 is formed from H-shaped steel. That is, each steel beam 20 is a steel beam with an H-shaped cross section, having a web 21 arranged in a vertical position, an upper flange 22 as an upper wall fixed to the upper end of the web 21, and a lower flange 23 fixed to the lower end of the web 21. The steel beams 20 are not limited to H-shaped steel, and may be formed from steel beams of other shapes, such as square steel pipes.

The framework structure 1 further has multiple outer steel beams 40 that span between a pair of steel columns 10 that are positioned on the outermost sides of the building 100. Each outer steel beam 40 is connected to a steel column 10 at one end and to another steel column 10 at the other end, so that it is supported in a spanned state between the adjacent steel columns 10. These multiple outer steel beams 40 are also main girders, and each is formed from H-shaped steel.

The concrete slab 30 is supported by the steel beams 20 and forms the floor portion of the upper floor of the building 100. Although not shown in detail, the concrete slab 30 is formed by pouring concrete onto a deck fixed to the steel beams 20.

As shown in FIG. 2, the concrete slab 30 has a main body portion 31 and a thickened portion 32.

In Figures 1 and 2, a portion of the main body 31 is omitted, but in this embodiment, the area (floor area) of the main body 31 in a plan view is larger than the area (floor area) of the thickened portion 32 in a plan view.

The main body 31 is a plate-like structure with a predetermined thickness between the bottom surface 31a and the top surface 31b, and constitutes a predetermined area of the inside of the building 100 of the concrete slab 30.

The thickened portion 32 has a thickness between the lower surface 32a and the upper surface 32b that is thicker than the thickness of the main body portion 31, and is integrally connected to the main body portion 31 to form a predetermined area of the concrete slab 30 on the outside of the building 100.

In this embodiment, the upper surface 32b of the thickened portion 32 is at the same height or level as the upper surface 31b of the main body portion 31, and the lower surface 32a of the thickened portion 32 is at a lower height or level than the lower surface 31a of the main body portion 31. Therefore, the concrete slab 30 has a stepped shape in which the lower surface 31a of the main body portion 31 is at a higher height or level than the lower surface 32a of the thickened portion 32.

Inside the concrete slab 30, multiple reinforcing bars 33 are arranged in a lattice pattern. In this embodiment, multiple reinforcing bars 33 are arranged in one layer inside the main body 31, and multiple reinforcing bars 33 are arranged in two layers, one above the other, inside the thickened portion 32. Note that, for convenience, only some of the reinforcing bars 33 are labeled in Figures 2 to 4.

In this embodiment, a portion of the thickened portion 32 protrudes outside the building 100 (outside the outermost steel beam 40), and the protruding portion forms a cantilever slab 34. The cantilever slab 34 may, for example, form the eaves of the building 100, but may also be used for other purposes, such as forming a veranda, balcony, etc. of the building 100.

The thickened portion 32 that constitutes the cantilever slab 34 is provided across both the inside and outside of the building 100, sandwiching the outermost outer steel beam 40 of the building 100. This increases the strength of the cantilever slab 34 that protrudes outward from the outer steel beam 40, and also increases the strength of a specified range of parts that are connected to the cantilever slab 34 and are inside the outer steel beam 40, thereby increasing the load resistance of the cantilever slab 34.

As shown in Figures 2 and 3, the main body 31 is supported by the steel beam 20 with its underside 31a resting on a part of the upper flange 22 of the steel beam 20. The steel beam 20 on which the concrete slab 30 rests is arranged to extend across the main body 31 and the thickened portion 32.

As shown in Figs. 1 and 2, the main body 31 may be placed on one or more small beams 50 that are spanned between adjacent steel beams 20 and supported by the small beams 50. The main body 31 may also be supported by multiple inner girders 60 that are spanned between multiple steel columns 10 inside the building 100.

The main body 31 is supported by the steel beam 20 by being placed on the upper flange 22 of the steel beam 20 at the lower surface 31a, whereas the thickened portion 32 is configured by embedding the other portion of the upper flange 22 of the steel beam 20 other than the portion on which the main body 31 is placed, as shown in Figs. 2 and 4. In this embodiment, the thickened portion 32 is configured by embedding the entire upper flange 22 of the steel beam 20 formed of H-shaped steel and a predetermined range above the web 21. In this way, the concrete slab 30 is not placed on the upper flange 22 of the steel beam 20 at the thickened portion 32, but is supported by the steel beam 20 inside the thickened portion 32 by embedding the upper flange 22 of the steel beam 20 inside the thickened portion 32. The other portion of the upper flange 22 of the steel beam 20 embedded in the thickened portion 32 is adjacent to the portion on which the main body 31 is placed in the direction in which the steel beam 20 extends.

As shown in Figures 1 and 2, the thickened section 32 may be placed on one or more small beams 70 that span between adjacent steel beams 20 and supported by the small beams 70 as well.

As described above, in the building framework structure 1 of this embodiment, the concrete slab 30 has a main body portion 31 and a thickened portion 32 that is integrally connected to the main body portion 31 and is formed to be thicker than the main body portion 31, so that the underside 31a of the main body portion 31 and the underside 32a of the thickened portion 32 form a step shape with different heights or levels. The main body portion 31 is supported by the steel beam 20 by being placed on part of the upper flange 22 of the steel beam 20, while the thickened portion 32 is supported by the steel beam 20 inside the thickened portion 32 by embedding a portion including the other part of the upper flange 22 of the steel beam 20. With this configuration, the building structure 1 of this embodiment can support the main body 31 and thickened portion 32 of the concrete slab 30 with the steel beams 20 in a simple configuration without using any padding material to match the height or level of the underside 31a of the main body 31 and the underside 32a of the thickened portion 32. This reduces the amount of steel used in the building structure 1, and reduces the cost and labor required for construction.

As shown in Figures 2 and 4, the skeleton structure 1 according to this embodiment can also be configured such that reinforcing bars 80 are embedded inside the thickened portion 32 above the steel beam 20, straddling the steel beam 20. In this embodiment, multiple reinforcing bars 80 shorter in length than the steel bars 33 are arranged parallel to each other and spaced apart from each other inside the thickened portion 32 between the upper flange 22 of the steel beam 20 and the upper reinforcing bar 33. Note that in Figure 2, for convenience, only one reinforcing bar 80 is labeled with a reference symbol.

In this way, by configuring the thickened portion 32 so that reinforcing steel bars 80 are embedded above the steel beams 20 and straddle the steel beams 20, the strength of the portion between the upper flange 22 and the upper surface 32b of the thickened portion 32 can be increased by the reinforcing steel bars 80, thereby preventing damage such as cracks from occurring in that portion.

Note that at least one reinforcing bar 80 must be provided.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the invention.

For example, in this embodiment, the thickened portion 32 constitutes a cantilever slab 34, but this is not limited to the above.

Reference Signs List 1 Building frame structure 10 Steel column 11 Joint 20 Steel beam 21 Web 22 Top flange (top wall)
23 Lower flange 30 Concrete slab 31 Main body 31a Lower surface 31b Upper surface 32 Thickened portion 32a Lower surface 32b Upper surface 33 Reinforcement bar 34 Cantilever slab 40 Outer steel beam 50 Small beam 60 Inner main beam 70 Small beam 80 Reinforcing steel bar 100 Building

Claims (3)

A building structure having a plurality of steel columns, a steel beam spanning adjacent steel columns, and a concrete slab supported by the steel beam,
The concrete slab is
A main body portion placed on a part of the upper wall of the steel beam;
a thickened portion that is integrally connected to the main body portion and is thicker than the main body portion, and into which another portion of the upper wall of the steel beam is embedded. The building structure of claim 1, in which reinforcing steel bars are embedded inside the thickened portion above the steel beams and straddle the steel beams. The building structure of claim 1 or 2, in which a portion of the thickened portion protrudes to the outside of the building to form a cantilever slab.

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