JP7503396B2 - Frame structure - Google Patents

Description

The present invention relates to a structural frame.

Patent Document 1 discloses a technology related to fire-resistant structural members used for pillars and beams that support buildings. This prior art is equipped with a column-shaped core material that receives the load, and a sheath material that covers the outer periphery of the core material along the longitudinal direction. The sheath material is integrally molded into a square tube shape and is made of wood that has been treated to be flame retardant, and the outer periphery of the core material fits into the inner periphery of the square tube-shaped sheath material.

Patent document 2 discloses technology related to an unbonded composite axial force member made of wood and metal members. In this prior art, wood is combined in an unbonded state in a position that prevents the metal member from buckling, and both ends of the metal member protruding from the ends of the wood are configured as input parts for the axial force.

Patent Document 3 discloses a technology related to a column-beam joint structure in which a wooden hybrid column made of steel concrete and a wooden panel surrounding it is joined to a steel beam. In this prior art, the wooden panel is positioned so that it does not come into direct contact with the steel beam at the joint between the column and the beam.

Patent No. 6469925 Patent No. 3661059 JP 2019-44514 A

In a column-beam structure with a combustible wooden core, the wooden core is primarily responsible for the long-term load. For this reason, the cross-section of the components needs to be larger than in structural materials made of reinforced concrete, etc.

In addition, in the event of a fire, in order to protect the combustible wooden core material, which bears the long-term load, from the heat of the fire, it is necessary to ensure that the covering material that covers the core material, which is composed of a wooden fuel layer, etc., is thick enough.

Therefore, a column-beam structure whose core is made of wooden structural materials has a larger component surface area than a structure made of structural materials such as reinforced concrete.

In light of the above, the present invention aims to reduce the cross-section of the members in a column-beam structure compared to a column-beam structure in which long-term loads are borne by wooden structural members.

The first aspect is a frame structure that includes a non-combustible first column-beam structure that receives a vertical load from the slab, and a wooden second column-beam structure that covers the outer surface of the first column-beam structure, has greater horizontal rigidity than the first column-beam structure, and is structurally insulated from the first column-beam structure and the slab.

In the first type of frame structure, the non-combustible first column and beam frame is covered by the wooden second column and beam frame, improving the design of the wooden building. The non-combustible first column and beam frame bears the vertical load from the slab, i.e., the first column and beam frame bears the long-term load. The wooden second column and beam frame is structurally insulated from the first column and beam frame and the slab, so it does not bear or bears very little vertical load from the slab, i.e., the second column and beam frame does not bear or bears very little long-term load.

On the other hand, the wooden second column and beam structure, which has high horizontal rigidity, mainly bears the load during an earthquake, while the non-combustible first column and beam structure, which has low horizontal rigidity and is structurally insulated from the second column and beam structure, bears less of the load during an earthquake.

In this way, the non-combustible first column and beam structure mainly bears the long-term load, while the wooden second column and beam structure mainly bears the earthquake load. Also, in the event of a fire, even if the wooden second column and beam structure burns and is destroyed, the non-combustible first column and beam structure will remain unburned and will remain independent.

Therefore, the first column-beam structure only needs to have a member cross-section capable of bearing long-term loads, and the second column-beam structure only needs to have a member cross-section capable of bearing earthquake loads, making it possible to make the member cross-sections efficient. Therefore, the member cross-sections of the column-beam structure can be made smaller than when long-term loads are borne by wooden structural materials.

The second aspect is the frame structure described in the first aspect, in which the second column-beam frame is structurally insulated from both the first column-beam frame and the slab by providing a gap or insulating material between them.

In the second embodiment of the frame structure, by providing a gap or insulating material between the second column-beam frame and the first column-beam frame and the slab, the second column-beam frame is easily structurally insulated from the first column-beam frame and the slab.

The third aspect is a frame structure according to the first or second aspect, in which the first column-beam frame is made of either reinforced concrete, steel-reinforced concrete, or steel.

In the third type of frame structure, reinforced concrete, steel reinforced concrete, and steel frame have better compressive performance than wood materials. Therefore, by constructing the non-combustible first column and beam frame, which bears the long-term load, from either reinforced concrete, steel reinforced concrete, or steel frame, the cross-section of the column and beam frame members can be further reduced.

According to the present invention, the cross-section of the members of a column-beam structure can be made smaller than that of a column-beam structure in which long-term loads are borne by wooden structural members.

This is an oblique view of the first column and beam frame that constitutes the frame of the building. This is an oblique view of the second column and beam frame that constitutes the frame of the building. FIG. 2 is a perspective view of the framework and slabs that constitute the building. 1 is a perspective view showing, in partial cross section, the joint portion of the first column-beam structure that constitutes the frame of a building and its vicinity. FIG. This is an oblique view showing, in partial cross section, the joint portion of the second column-beam structure that constitutes the frame of the building and its vicinity. This is an oblique view showing, in partial cross section, the joint portion of the frame that constitutes the building and its vicinity. FIG. 6 is a perspective view of a slab. This is a horizontal cross-sectional view of a column that constitutes the building's structure. This is a vertical cross-sectional view along the Y direction of the beams and slabs that constitute the building frame. FIG. 13 is a perspective view of a frame and a slab according to a first modified example. A vertical cross-sectional view along the Y direction of the beams and slabs that constitute the frame of the second modified example.

<Embodiment>
A frame structure according to an embodiment of the present invention will be described below. The vertical direction is defined as the Z direction, and two mutually orthogonal directions, that is, horizontal directions perpendicular to the vertical direction, are defined as the X direction and the Y direction.

[composition]
First, the configuration of the frame of a building to which the frame structure of this embodiment is applied will be described.

The frame 12 of the building 10 shown in Figure 3 is composed of columns 20 (see Figure 8) and beams 30 (see Figure 9). The frame structure 14 of this frame 12 is composed of a first column-beam frame 100 (see Figures 1, 4, and 6) made of reinforced concrete and non-combustible, and a second column-beam frame 200 (see Figures 2, 5, and 6) made of wood.

As shown in Figure 6, the wooden second column-beam structure 200 (see Figures 2 and 5) covers the outer surface 102 (see Figures 1 and 4) of the first column-beam structure 100, has greater horizontal rigidity than the first column-beam structure 100, and is structurally insulated from the first column-beam structure 100 and the slab 50 (see Figures 3, 7, and 9) described below.

In this embodiment, the horizontal stiffness ratio between the second column-beam structure 200 and the first column-beam structure 100 is approximately 10:1, but is not limited to this.

As shown in Figures 1, 4 and 6, the first column-beam structure 100 is composed of a first column 120 (see Figure 8) and a first beam 130 (see Figure 9) made of reinforced concrete.

As shown in Figures 2, 5, and 6, the second column-beam structure 200 is composed of a wooden second column 220 (see Figure 8) and a second beam 230 (see Figure 9). In this embodiment, the wooden second column 220 and the second beam 230 are joined by a plate and a drift pin (not shown) that are embedded across the second column 220 and the second beam 230, but this is not limited to this.

In this embodiment, the wood constituting the second wooden column-beam structure 200 (second wooden column 220 and second beam 230) has not been treated to be flame retardant or non-combustible, but may be treated to be flame retardant or non-combustible.

In addition, the wood constituting the second wooden column-beam structure 200 (second wooden column 220 and second beam 230) in this embodiment can be solid wood, laminated wood, laminated veneer lumber, cross-laminated timber, etc.

As shown in Figures 6 and 8, the column 20 is composed of the aforementioned first column 120 of reinforced concrete construction that constitutes the core material, and the aforementioned second column 220 made of wood that covers the outer peripheral surface 122 (see Figures 1 and 4) of the first column 120. A gap 252 is formed between the outer peripheral surface 122 (see Figures 1 and 4) of the first column 120 and the inner peripheral surface 222 (see Figures 2 and 5) of the second column 220, and expanded polystyrene material 250, an example of an insulating material, is provided in the gap 252. As a result, the first column 120 and the second column 220 in the column 20 are structurally insulated, and the two are not integrated.

As shown in Figures 6 and 9, the beam 30 is composed of the aforementioned reinforced concrete first beam 130 that constitutes the core material, and the aforementioned wooden second beam 230 (see also Figure 5) that covers the outer surface 131 (see also Figure 4) and bottom lower surface 132 (see also Figure 4) of the first beam 130. The second beam 230 is groove-shaped with an open upper side (see also Figure 5).

The outer surface 131 of the first beam 130 and the inner surface 231 of the second beam 230 (see FIG. 5) are in contact with each other in a non-bonded state. However, a gap 262 is formed between the bottom lower surface 132 of the first beam 130 and the bottom upper surface 232 of the second beam 230 (see FIG. 5), and polystyrene foam material 260, an example of an insulating material, is provided in the gap 262. As a result, the first beam 130 and the second beam 230 in the beam 30 are structurally insulated, and the two are not integrated.

The joint between the first column 120 and the first beam 130 and the joint between the second column 220 and the second beam 230 may be of any joint structure, for example, a pin joint, a semi-rigid joint, or a rigid joint.

As shown in Figures 3, 7 and 9, a reinforced concrete slab 50 is provided on top of the beams 30 of the frame 12 of the building 10.

As shown in Figures 7 and 9, the slab 50 is joined to the top surface 133 of the first beam 130 made of reinforced concrete. However, a gap 272 is formed between the slab 50 and the top surface 233 of the second wooden beam 230, and expanded polystyrene material 270 is provided in the gap 272 as an example of an insulating material. As a result, the first beam 130 made of reinforced concrete that constitutes the beam 30 bears the load of the slab 50, while the second wooden beam 230 that constitutes the beam 30 is structurally insulated from the slab 50, and the two are not integrated.

The slab 50 is not limited to being made of reinforced concrete. The slab 50 may be made of lightweight aerated concrete panels and wood boards, for example.

[Action and Effect]
Next, the operation and effects of this embodiment will be described.

The frame 12 of the building 10 has a non-flammable first column-beam frame 100 covered by a wooden second column-beam frame 200, improving the design of the wooden building 10.

In addition, the fireproof first column-beam structure 100 bears the vertical load from the slab 50, i.e., the first column-beam structure 100 bears the long-term load.

However, since the wooden second column-beam structure 200 is structurally insulated from the first column-beam structure 100 and the slab 50, it is not subjected to or is subjected to very little vertical load from the slab 50, i.e., the second column-beam structure 200 does not bear or is subjected to very little long-term load.

By ensuring a sufficient gap 272 between the upper surface 133 of the second beam 230 constituting the second column-beam structure 200 and the slab 50, it is possible to prevent or minimize the vertical load from the slab 50. The gap 272 that prevents or minimizes the vertical load from the slab 50 can be found by calculating the deflection of the slab 50.

On the other hand, the wooden second column-beam structure 200, which has high horizontal stiffness, mainly bears the load during an earthquake, while the non-combustible first column-beam structure 100, which has low horizontal stiffness and is structurally insulated from the second column-beam structure 200, bears less of the load during an earthquake.

Here, the seismic load borne by the second column-beam structure 200 and the first column-beam structure 100 is basically the horizontal stiffness ratio. In this embodiment, the horizontal stiffness ratio between the second column-beam structure 200 and the first column-beam structure 100 is about 10:1, so the seismic load ratio borne by the second column-beam structure 200 and the first column-beam structure 100 is also about 10:1.

The seismic load borne by the second column-beam structure 200 and the first column-beam structure 100 is not determined solely by the horizontal stiffness ratio. For example, it is also affected by the joint structure between the first column 120 and the first beam 130 and the joint structure between the second column 220 and the second beam 230, such as pin joints, semi-rigid joints, and rigid joints.

In this way, the non-combustible first column-beam structure 100 mainly bears the long-term load, and the wooden second column-beam structure 200 mainly bears the earthquake load. Also, in the event of a fire, even if the wooden second column-beam structure 200 burns and is destroyed, the non-combustible first column-beam structure 100 remains unburned, and the building 10 remains self-supporting.

Therefore, the first column-beam structure 100 only needs to have a member cross-section capable of bearing a long-term load. In other words, the first column 120 and the first beam 130 only need to have a member cross-section capable of bearing a long-term load.

On the other hand, the second column-beam structure 200 only needs to have a member cross-section capable of bearing the earthquake load. In other words, the second column 220 and the second beam 230 only need to have a member cross-section capable of bearing the earthquake load.

Therefore, the first column-beam structure 100 and the second column-beam structure 200, in other words the first column 120, first beam 130, second column 220 and second beam 230, can each have an efficient member cross-section, and the member cross-section of the structure 12, i.e. the member cross-section of the column 20 and beam 30, can be made smaller than when long-term loads are borne by structural materials whose core is flammable wood.

In addition, the first column 120 and the first beam 130 that make up the first column-beam structure 100 are made of reinforced concrete, which has better compressive performance than wood materials, so the cross-section of the components of the first column-beam structure 100 that bear the long-term load can be made smaller.

In addition, by providing expanded polystyrene materials 250, 260, 270 in the gaps 252, 262, 272 between the second column-beam structure 200 and the first column-beam structure 100 and slab 50, the second column-beam structure 200 can be easily structurally insulated from the first column-beam structure 100 and slab 50.

[Modification]
Next, a modification of this embodiment will be described.

(First Modification)
In the frame structure 15 of the frame 13 of the first modified example shown in Fig. 10, a diagonal brace 280 is provided on the second column-beam frame 200. Specifically, the diagonal brace 280 is provided connected to the second column 220 and the second beam 230 constituting the frame structure 15 near the joint between them.

In this way, by providing the diagonal braces 280 to the second beam-column structure 200, the horizontal rigidity of the second beam-column structure 200 is increased. Therefore, the seismic load that the second beam-column structure 200 can bear can be increased while suppressing the member cross-section.

(Second Modification)
In the frame structure 19 of the frame 17 of the second modified example shown in Fig. 11, the first beam 330 constituting the first column-beam frame 101 is made of a steel frame, and in this modified example, is made of an H-shaped steel. The first column 120 (see Fig. 1) constituting the first column-beam frame 101 is made of reinforced concrete.

The beams 31 that make up the frame 17 are composed of a first beam 330 made of the H-shaped steel mentioned above, a second beam 230 made of wood, and a beam side portion 350.

The first beam 330, which is made of H-shaped steel, supports the load of the slab 50 on the upper surface 333 of the upper flange 332. Studs or the like to be embedded in the slab 50 may be provided on the upper surface 333 of the upper flange 332 of the first beam 330.

A gap 262 is formed between the lower surface 331 of the lower flange 332 of the first beam 330 and the bottom upper surface 232 of the second beam 230, and polystyrene foam material 260 as an example of an insulating material is provided in the gap 262.

The beam side portions 350 are provided between the upper and lower flanges 332 on both sides of the web 334 of the first beam 330, which is made of H-shaped steel, and are made of heat-resistant materials such as concrete, cement, mortar, gypsum, gypsum board, calcium silicate board, and rock wool.

In this way, by providing beam side portions 350 made of heat-resistant material between the upper and lower flanges 332 on both sides of the web 334 of the first beam 330, the fire resistance of the first beam 330 made of H-shaped steel is improved.

＜Other＞
The present invention is not limited to the above embodiment.

For example, in the above embodiment, the non-combustible first column-beam structure 100 was made of reinforced concrete, but this is not limited thereto. It may be made of steel-reinforced concrete or steel. Alternatively, it may be made of a non-combustible material other than reinforced concrete, steel-reinforced concrete, and steel-reinforced concrete. From another perspective, the first column-beam structure 100 may be replaced with another material as long as it can ensure non-combustibility and support for vertical loads. In addition, the first column and the first beam may be made of different materials. The second modified example described above is an example in which the first column and the first beam are made of different materials.

Here, when at least one of the first column and the first beam that constitute the first column-beam frame 100 is made of steel material, the steel material may require fire-resistant coating or the like. Note that the beam side portion 350 of the second modified example described above functions as fire-resistant coating.

In addition, for example, in the above embodiment, the second column-beam structure 200 is structurally insulated from the first column-beam structure 100 and the slab 50 by providing expanded polystyrene materials 250, 260, 270 in the gaps 252, 262, 272 between the second column-beam structure 200 and the first column-beam structure 100 and the slab 50, but this is not limited to the above. Insulating materials other than the expanded polystyrene materials 250, 260, 270, such as urethane sponge, may also be used.

Also, only gaps 252, 262, 272 may be provided between the second column-beam structure 200 and the first column-beam structure 100 and slab 50 to structurally insulate the second column-beam structure 200 from the first column-beam structure 100 and slab 50. In short, it is sufficient that the structure does not transmit or barely transmits loads between the second column-beam structure 200 and the first column-beam structure 100 and slab 50.

Furthermore, the present invention may be implemented in various ways without departing from the spirit of the invention. The embodiments and modifications may be implemented in combination as appropriate.

REFERENCE SIGNS LIST 10 Building 12 Frame 13 Frame 14 Frame structure 15 Frame structure 17 Frame 19 Frame structure 20 Column 30 Beam 31 Beam 50 Slab 100 First column-beam frame 101 First column-beam frame 102 Outer surface 120 First column 130 First beam 200 Second column-beam frame 220 Second column 230 Second beam 250 Expanded polystyrene material (an example of an insulating material)
252 Gap 260 Styrofoam material (an example of insulating material)
262 Gap 270 Styrofoam material (an example of insulating material)
272 Gap 280 Diagonal brace 330 First beam

Claims (5)

A non-combustible first column-beam frame that receives vertical load from the slab;
a second wooden column-beam frame covering an outer surface of the first column-beam frame and having greater horizontal rigidity than the first column-beam frame;
Equipped with
The first column-beam frame is composed of a first beam having an upper surface joined to the slab and a first column to which the first beam is joined,
The second beam-column structure is composed of a second beam having a U-shaped cross section, the second beam having an outer portion covering the side portion of the first beam and forming a first gap between it and the slab, and a bottom lower portion joined to the lower end portion of the outer portion and forming a second gap between it and the bottom underside of the first beam, and a cylindrical second column having a portion where the slab contacts the side surface, covering the outer periphery of the first column, through which the first beam passes and to which the second beam is joined, so that a gap is formed between the first column and the second beam.
Frame structure. The first gap and the second gap are provided with an insulating material that provides structural insulation.
The frame structure according to claim 1. The insulating material is polystyrene foam or urethane sponge.
The frame structure according to claim 2. The first column-beam structure is made of any one of reinforced concrete, steel reinforced concrete, and steel.
The frame structure according to any one of claims 1 to 3. The second column-beam frame is provided with a diagonal brace.
The frame structure according to any one of claims 1 to 4.