JP7509653B2 - Reinforcement structure of building frame - Google Patents

Description

The present invention relates to a reinforcing structure for building frames.

A reinforcement structure that can be applied to existing buildings has been proposed as one of the structures for strengthening the earthquake resistance of buildings. This reinforcement structure comprises multiple shells that are placed on the outside of the building and face each of the multiple stories, and multiple pins that are provided at the column-beam joints of each story of the building. Each shell is made of shaped steel, and has a portion that extends vertically along the multiple columns of each story of the building, and a portion that extends horizontally along the multiple beams. Each shell is supported on the building via multiple pins, and the multiple shells are connected to each other at the top and bottom, forming an overall lattice pattern. With this, it is believed that the shells supported on the building by pins can prevent the effects of moment transmission to the building during an earthquake.

JP 2009-97165 A

In consideration of the conventional earthquake-resistance reinforcement, the present invention provides a new reinforcement structure that contributes to the reinforcement of building frames. The present invention also provides a new frame reinforcement structure that leaves the wood surface exposed, allowing the texture of wood to be expressed.

As one embodiment of the reinforcing structure for a building frame according to the present invention, the reinforcing structure comprises a wooden panel that is placed on the outside of the building and faces the frame, and a number of steel rod members that support the wooden panel on the frame. Each of the rod members has a base end that is fixed to the frame and a tip end that is pressed into a number of holes provided in the wooden panel.

In another embodiment of the reinforcing structure for a building frame according to the present invention, the reinforcing structure comprises the wooden panel, a plurality of steel rod members, and a plurality of reinforced concrete blocks. In this embodiment, the reinforced concrete blocks are fixed to the frame. Each of the rod members has a base end fixed to the reinforced concrete block and a tip end pressed into a plurality of holes provided in the wooden panel, and the rod members support the wooden panel to the frame via the reinforced concrete blocks. In the present invention, a "rod member" refers to an object that extends straight from its base end to its tip end and has the same thickness and the same cross-sectional shape. The rod member is, for example, a drift pin.

The reinforcing structure of the present invention has wooden panels that are supported by the building frame and face the frame, which contribute to reinforcing the frame and increasing its rigidity.

In addition, in the reinforcement structure of the present invention, the tips of the steel rods that support the wooden panel to the frame are pressed into the holes in the wooden panel, and the wooden panel is hung on the rods. This allows for the relative displacement of the wooden panel in the lateral direction with respect to the building frame when a horizontal displacement occurs in the building during an earthquake, and the associated relative movement and deformation (bending) of the tips of the rods in the axial direction with friction inside the holes with respect to the wooden panel. A portion of the earthquake load acting on the frame is used for the relative movement and deformation of the rods, which reduces a portion of the earthquake load and reduces the inter-story displacement of the building during an earthquake.

With respect to the wooden panel, the relative movement of the tip of the bar contributes to reducing the magnitude of the shear force that the wooden panel receives as the tip of the bar bends. This prevents shear failure of the wooden panel under the action of earthquake loads. Preferably, a stopper is provided to prevent the tip of the bar from slipping out of the hole in the wooden panel due to excessive relative movement that may occur at the tip of the bar depending on the scale of the earthquake.

The reinforced structure including the reinforced concrete blocks is particularly suitable for reinforcing steel-framed frames. The reinforced concrete blocks act as a thermal bridge avoidance means for blocking heat transfer from the frame to the wooden panels in the event of a fire in the building, and preventing the wooden panels from igniting. Each reinforced concrete block can be fixed to the frame at its columns or at both the columns and beams. The reinforced concrete blocks can also be integral with a reinforced concrete slab formed on the frame and forming part of the building.

In addition, according to the present invention, the wooden panels can present a wood-like texture by exposing the wooden surface to the inside and outside of the building. Furthermore, the reinforcing structure according to the present invention contributes to reducing the eccentricity of single-core buildings.

FIG. 2 is a front view showing a schematic diagram of a building frame and a reinforcing structure applied thereto; FIG. 2 is a longitudinal cross-sectional view taken along line 2-2 of FIG. 3 is a cross-sectional view taken along line 3-3 of Figure 2, except that the pillars are shown in non-section to avoid cluttering the figure. FIG. 11 is a partial front view illustrating another example of a reinforcing structure. FIG. 11 is a partial front view illustrating a schematic diagram of still another example of a reinforcing structure.

Referring to FIG. 1, there is shown a portion of a newly constructed building 10 having multiple floors, and a reinforcing structure 14 applied to multiple steel-framed frames 12 that are continuous in the horizontal direction (left and right direction in the figure) on one floor of the building 10. Instead of the illustrated example in which the reinforcing structure 14 is applied to multiple horizontally continuous frames 12, it can be applied to one or multiple frames 12 that are discontinuous in the horizontal direction. The reinforcing structure 14 can also be applied to frames made of reinforced concrete.

Each frame 12 of the building 10 to which the reinforcing structure 14 is applied is composed of a pair of columns 16 and a beam 18 arranged between and rigidly connected to the columns 16, and faces the outside of the building 10. In the figure, the reference numeral 20 indicates two columns constituting the frame of another story located on the floor above each frame 12 of the first story. The multiple frames of the other story can also be reinforced by the reinforcing structure 14. The reference numeral 22 indicates a reinforced concrete slab of the other story formed on the beams 18 of the multiple frames 12 of the first story and the other beams 23 (beams rigidly connected to the columns 16 and extending toward the inside of the building 10) (see Figures 2 and 3).

The illustrated column 16 (as well as column 20) is made up of two steel pipes, one above the other, with a rectangular cross-sectional shape, as shown in Figs. 2 and 3. The two steel pipes 16a and 16b that make up the column 16 are joined to each other via a rectangular diaphragm 24 (see Figs. 2 and 3) placed between them. The upper steel pipe 16a of the column 16 is joined to the column 20 (more specifically, the lower of the two steel pipes that make up the column 20) via a rectangular diaphragm 26. On the other hand, the illustrated beams 18 and 23 are made of H-shaped steel, and are rigidly joined to both columns 16 via the diaphragms 24 and 26. Note that in Fig. 1, the diaphragms 24 and 26 are omitted to avoid cluttering the drawing.

The reinforcing structure 14 comprises a wooden panel 28, two cast-in-place reinforced concrete blocks 30 fixed to the frame 12, and a number of steel rod members 32 (Figures 2 and 3), and the wooden panel 28 is supported by the rod members 32 via both reinforced concrete blocks 30 to each frame 12.

The wooden panels 28 constituting the reinforcing structure 14 are made of cross-laminated timber (CLT), laminated veneer lumber (LVL), solid wood, etc. The wooden panels 28 are placed on the exterior of the building 10 and face the multiple frames 12 and reinforced concrete blocks 30. Preferably, the wooden panels 28 are placed below the reinforced concrete slab 22 at a distance to allow deformation, and a gap 33 is provided between the reinforced concrete slab 22 and the wooden panels 28.

The wooden panel 28 has a number of holes 28a corresponding to the number of rod members 32. The width dimension (vertical length) of the wooden panel 28 can be determined as desired. The illustrated wooden panel 28 has a relatively small width dimension, taking into consideration the lighting entering the interior of the building 10 through the openings defined by the frame 12. For this reason, the wooden panel 28 extends in a strip shape in the horizontal direction, covering the upper part of the frame 12 (the upper parts of both columns 16 and the beam 18) when viewed from the outside of the building 10. The thickness dimension of the wooden panel 28 can also be determined as desired.

The two reinforced concrete blocks 30 are fixed to the frames 12 at the two columns 16 that constitute them. A plurality of headed studs 34 extending horizontally are embedded in the illustrated reinforced concrete block 30, and each headed stud 34 is fixed to the column 16 at the tip of its shaft. The illustrated reinforced concrete block 30 is formed by pouring concrete into a formwork (not shown) that is installed and reinforced to form both the reinforced concrete slab 22 and the concrete block 30 at the construction site of the building 10. Therefore, the illustrated reinforced concrete block 30 is connected to the reinforced concrete slab 22 and is integrated with it. However, instead of the illustrated example, the reinforced concrete block 30 can be formed as an independent one separated from the reinforced concrete slab 22 by casting in place. Also, instead of being formed by casting in place, the reinforced concrete block 30 can be made of precast concrete.

In the illustrated example, the reinforced concrete block 30 has a width dimension that is approximately equal to the width dimension of the column 16, a length dimension (vertical length) that is greater than the height dimension (beam depth) of the beam 18 and smaller than the width dimension of the wooden panel 28, and a thickness dimension that is approximately equal to the thickness dimension of the wooden panel 28. However, the width dimension, length dimension, and thickness dimension of the reinforced concrete block 30 can be determined arbitrarily.

Now, referring to FIG. 4, another example of a reinforced concrete block 30 is shown. The reinforced concrete block 30 of this example has a longer length dimension compared to the reinforced concrete block 30 shown in FIG. 1. In this example, the width dimension of a portion 28b of the wooden panel 28 facing the reinforced concrete block 30 is set to be larger than the width dimension of the other portion 28c in accordance with the length dimension of the reinforced concrete block 30.

Referring to FIG. 5, a further example of a reinforced concrete block 30 is shown. The reinforced concrete block 30 has an overall T-shaped elevation and has an upper portion 30a and a lower portion 30b that are larger in width and length than the reinforced concrete block 30 shown in FIG. 1. In this example, the upper portion 30a of the reinforced concrete block 30 is fixed to both the column 16 and the beam 18 of another frame that shares the column 16 as a common component, and the lower portion 30b is fixed to the column 16. As in the example shown in FIG. 4, the width of a portion 28b of the wooden panel 28 facing the reinforced concrete block 30 is set to be larger than the width of the other portion 28c in accordance with the length of the reinforced concrete block 30. This allows the frame 12 to be reinforced at both the columns 16 and the beam 18 between the columns 16.

The rod members 32 supporting the wooden panel 28 have a base end 32a and a tip end 32b facing each other. The rod members 32 extend straight from the base end 32a to the tip end 32b and have the same thickness and the same cross-sectional shape. The rod members 32 are preferably made of drift pins having a circular cross-sectional shape. The base end 32a of the rod members 32 is embedded and fixed in the reinforced concrete block 30 and extends parallel to the headed studs 34 in the reinforced concrete block 30. The tip end 32b of the rod members 32 protrudes from the reinforced concrete block 30 toward the outside of the building 10. The tip ends 32b of the multiple rod members 32 are each pressed into the multiple holes 28a of the wooden panel 28. Therefore, the tip end 32b of the rod members 32 is in contact with the entire peripheral surface of the peripheral wall surface of the hole 28a and is in a state of being compressed by the peripheral wall surface of the hole 28a. The degree of compression, i.e., the contact pressure, that the tip 32b of the rod member 32 receives can be determined arbitrarily by appropriately selecting the thickness (diameter) of the rod members 32, the distance between the rod members 32, the length of the tip 32b of the rod members 32, the total number of rod members 32, or a combination of these. The wooden panel 28 is supported by the frame 12 via the reinforced concrete blocks 30 while hanging from multiple rod members 32.

The frame 12 is reinforced at both columns 16 with wooden panels 28, which increases the rigidity of the frame 12 and reduces the inter-story displacement, which is the relative horizontal displacement of each floor of the building 10 with respect to the floor below during an earthquake. The reinforcing structure 14 also contributes to reducing the eccentricity of the single-core building. Furthermore, the wooden panels 28 can present a wood texture by exposing the wooden surface of the building 10 both inside and outside.

According to this reinforcing structure 14, when horizontal displacement occurs in the building 10 during an earthquake, the wooden panel 28 is displaced horizontally relative to the multiple frames 12 of the building 10. At this time, in conjunction with the relative displacement of the wooden panel 28, the rod member 32 receives a pulling force from the hole 28a of the wooden panel 28 relative to the frame 12. As a result, the tip 32b of the rod member 32 moves relatively inside the hole 28a of the wooden panel 28 in its axial direction, and a part of it is pulled out to the outside of the hole 28a. At this time, a frictional force is generated between the peripheral wall surface of the hole 28a and the tip 32b of the rod member 32. In addition, a part of the tip 32b of the rod member 32 pulled out to the outside of the hole 28a is bent. A portion of the earthquake load acting on the frame 12 is consumed by the relative movement and bending of the rod members 32 against the frictional force, thereby reducing a portion of the earthquake load and reducing the inter-story displacement of the building 10 during an earthquake.

The relative movement of the tip 32b of the rod 32 also contributes to reducing the shear force that the bending of the tip 32b of the rod 32 exerts on the wooden panel 28, preventing shear failure of the wooden panel 28 under the action of earthquake loads. Preferably, a stopper 36 (Fig. 2) is provided to prevent excessive relative movement that may occur in the tip 32b of the rod 32 depending on the scale of the earthquake and the associated slipping out of the tip 32b of the rod 32 from the hole in the wooden panel 28.

The stopper 36 can be, for example, a steel member with an angle shape having one side fixed to a part of the reinforced concrete slab 22 that protrudes to the outside of the building 10 (see FIG. 2). The steel member has another side connected to the first side that faces the outer surface of the wooden panel 28 that faces the outside of the building 10.

Instead of the illustrated example, the stopper 36 may be another example consisting of a cylindrical steel member (not shown) having an outer diameter larger than the diameter of the hole 28a, which is fixed to the tip 32b of the rod member 32 in a manner described below. That is, in this other example, the hole 28a opening on the inner surface of the wooden panel 28 facing the inside of the building 10 is replaced by a through hole of the same diameter as the hole 28a opening on both the inner and outer sides of the wooden panel 28, and the tip 32b of the rod member 32 protrudes from the outer surface of the wooden panel 28 through the through hole. In addition, the tip portion of the tip 32b of the rod member 32 protruding from the through hole is fitted and fixed to the cylindrical steel member. Here, the cylindrical steel member is located at a location spaced from the outer surface of the wooden panel 28 in the axial direction of the rod member 32. As a result, the cylindrical steel member functions as a stopper that prevents the tip 32b of the rod member 32 from slipping out of the hole 28a in the wooden panel 28.

In the illustrated reinforcing structure 14 applied to a steel frame 12, the reinforced concrete blocks 30 act as a thermal bridge avoidance means to block the transfer of heat from the frame 12 to the wooden panels 28 in the event of a fire in the building 10, thereby preventing the wooden panels 28 from igniting.

However, for both steel and reinforced concrete frames, it is possible to have a reinforcement structure that does not have reinforced concrete blocks 30. In this reinforcement structure, for a steel frame, the base ends 32a of the multiple rod members 32 are fixed directly to both columns 16 of the frame 12, or to both columns 16 and the beams 18 between them. For a reinforced concrete frame, the base ends 32a of the multiple rod members 32 are embedded in the reinforced concrete that forms the frame (both columns 16, or to both columns 16 and the beams 18 between them).

10 Building 12 Frame 14 Reinforcement structure 16 Column 18 Beam 22 Reinforced concrete slab 28 Wooden panel 30 Reinforced concrete block 32 Rod member 36 Stopper

Claims (6)

A reinforcing structure for a building frame, comprising:
a wooden panel disposed on the exterior of the building and facing the frame;
a plurality of steel rod members supporting the wooden panels on the frame;
A reinforcing structure in which each of the multiple rod members has a base end fixed to the frame and a tip end press-fitted into a plurality of holes provided in the wooden panel. A reinforcing structure for a building frame, comprising:
a wooden panel disposed on the exterior of the building and facing the frame;
A plurality of reinforced concrete blocks fixed to the frame;
a plurality of steel rod members supporting the wooden panel on the frame via the reinforced concrete block;
A reinforcement structure in which each of the multiple rod members has a base end fixed to the reinforced concrete block and a tip end pressed into a plurality of holes provided in the panel. The reinforced structure described in claim 2, in which each reinforced concrete block is fixed to a column or to both the column and the beam that constitute the frame. The reinforced structure according to claim 2 or 3, wherein the reinforced concrete block is integral with a reinforced concrete slab formed on the frame and forming part of the building. The reinforcing structure according to any one of claims 1 to 4 further comprises a stopper that prevents the tip of the rod member from slipping out of the hole in the wooden panel. The reinforcement structure according to any one of claims 1 to 5, wherein the rod member is a drift pin.

Images