JP7388968B2 - Earthquake-resistant structure - Google Patents

Description

The present invention relates to an earthquake-resistant structure.

Conventionally, vibration control structures and earthquake-resistant structures using a pair of U-shaped dampers have been known. In these structures, it is preferable in terms of energy absorption performance that the damper is always curved with the same curvature.

Therefore, in Patent Document 1, by making the pair of restraining parts extend longer in the horizontal or vertical direction than the pair of dampers, the interstory displacement of the building increases, and the relative displacement of the pair of restraining parts increases accordingly. Even in such a case, the damper is configured to prevent the damper from protruding from the pair of restraining portions, thereby suppressing uneven deformation of the damper.

JP2009-270336A

However, in the technology described in Patent Document 1, since the pair of restraint parts extend longer than the pair of dampers, it is necessary to avoid interference with other nearby members, and the width of the panel frame must be increased. Therefore, there was a risk that the degree of freedom in designing the floor plan of the building would be reduced.

In view of such circumstances, an object of the present invention is to provide an earthquake-resistant structure that can ensure high earthquake-resistant performance while achieving compactness.

The gist of the present invention is as follows.
(1) comprising an upper horizontal member, a lower horizontal member, and a pair of energy absorbing members provided between the upper horizontal member and the lower horizontal member,
The energy absorbing member includes a curved portion, a pair of intermediate portions that extend continuously from both ends of the curved portion, and a pair of fixed portions that continuously extend from the ends of the pair of intermediate portions. , the pair of fixed portions is configured to undergo relative displacement in the extending direction in response to relative displacement in the horizontal direction between the upper horizontal member and the lower horizontal member;
The pair of energy absorbing members have an earthquake-resistant structure, wherein the pair of energy absorbing members are held close to each other by a pair of holding parts so that the curved parts face each other.

(2) being held by the holding part having a dimension equal to the dimension from the end of one of the fixed parts on the same side of the pair of energy absorbing members to the end of the other fixed part; The earthquake-resistant structure described in (1) above.

(3) The earthquake-resistant structure according to (1) above, including a holding part that can continuously hold a plurality of pairs of the pair of energy absorbing members.

(4) The earthquake-resistant structure according to (3) above, wherein the pair of holding parts are configured so that a plurality of pairs of the energy absorbing members can be installed continuously in the vertical direction.

(5) The earthquake-resistant structure according to any one of (1) to (4) above, wherein the energy absorbing member is composed of multiple layers, and the thickness of the inner layer is smaller than the thickness of the outer layer.

According to the present invention, it is possible to provide an earthquake-resistant structure that is compact and can ensure high earthquake-resistant performance.

FIG. 1 is a front view showing an earthquake-resistant structure according to a first embodiment of the present invention. It is a figure which shows an example of an energy absorption member. FIG. 3 is a diagram showing the arrangement of energy absorbing members used in this embodiment. It is a figure which shows typically the deformation of the energy absorption member in this embodiment. It is a figure which shows the arrangement|positioning which becomes comparison of an energy absorption member. It is a figure which shows typically the deformation|transformation of the energy absorption member used as a comparison. FIG. 7 is a front view showing an earthquake-resistant structure according to a second embodiment of the present invention. FIG. 7 is a front view showing an earthquake-resistant structure according to a third embodiment of the present invention. FIG. 7 is a front view showing an earthquake-resistant structure according to a fourth embodiment of the present invention. It is a front view showing the earthquake-resistant structure concerning the 5th embodiment of the present invention. It is a figure which shows an example of an energy absorption member. It is a figure which shows an example of the method of superimposing layers. It is a figure which shows the other example of the method of superimposing layers. FIG. 7 is a diagram illustrating another example of a method of overlapping layers.

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

[First embodiment]
FIG. 1 is a front view showing an earthquake-resistant structure according to a first embodiment of the present invention.
The frame of a building to which the earthquake-resistant structure according to the present invention is applied is constructed on a reinforced concrete foundation beam and a foundation beam, and is composed of a steel upper frame made of steel columns, beams, etc. In this example, an earthquake-resistant structure installed on the second floor or above will be described, but the earthquake-resistant structure of the present invention can also be installed on the ground floor. As shown in FIG. 1, the frame has an upper floor beam (upper horizontal member) 5 and a lower floor beam (lower horizontal member) 6. The "up and down" here refers to the top and bottom in the vertical direction of the building, and corresponds to the top and bottom in the illustration. Further, left and right are one side and the other side in the horizontal direction in a horizontal plane perpendicular to the vertical direction, and are the left and right sides in the drawing.

As shown in FIG. 1, the upper floor beam 5 and the lower floor beam 6 extend in the horizontal direction. Although not shown, the ends of the upper floor beam 5 and the lower floor beam 6 are joined to columns or other horizontal members. The upper deck beam 5 and the lower deck beam 6 are made of H-shaped steel, and the upper and lower flanges have holes drilled at a predetermined pitch for bolting other members.

<Energy absorbing member>
FIG. 2 is a diagram showing an example of an energy absorbing member. FIG. 3A is a diagram showing the arrangement of energy absorbing members used in this embodiment. FIG. 3B is a diagram schematically showing deformation of the energy absorbing member in this embodiment.
The energy absorbing member 4 has the function of absorbing energy and attenuating the shaking of the building by deforming itself in accordance with the interstory deformation of the building when a horizontal force such as an earthquake acts on the building. . The energy absorbing member 4 has a substantially U-shape, and includes a curved portion 4a, a pair of intermediate portions 4b extending continuously from both ends of the curved portion 4a, and a pair of intermediate portions 4b extending continuously from each end of the pair of intermediate portions 4b. It has a pair of fixing parts 4c that extend as shown in FIG. Parts of the pair of intermediate portions 4b and the pair of fixed portions 4c form a pair of opposing portions that oppose each other (in the non-deformed state). The energy absorbing member 4 is formed into the above-mentioned shape (approximately U-shape) by bending a rectangular plate-shaped steel material. In the energy absorbing member 4 having such a shape, the pair of fixing parts 4c repeat relative displacement in the positive and negative directions in the extending direction while maintaining a parallel state to each other, so that (the curved part in one opposing part) The part near the curved part curves with almost the same bending strain as the curved part, and the part near the curved part in the other opposing part becomes flat, and the energy corresponding to the displacement (deformation) is absorbed. Can be absorbed.

The energy absorbing member 4 has a plurality of holes drilled in the fixed part 4c of the seismic element for bolt connection, and is connected to the contact surface of the mounting member by bolt connection etc. as described later. The fixed portion 4c is a region where deformation into a curved shape is restrained and a flat shape is maintained, and the region where an arcuate curved shape is always maintained is a curved portion 4a, which changes between a curved shape and a flat shape. The possible region is the intermediate portion 4b.

In addition, the state in which one intermediate portion 4b is deformed into a curved shape up to the boundary with the fixed portion 4c, and the other intermediate portion 4b is flat until the boundary with the curved portion 4a is the relative state of the energy absorbing member 4. This is a state in which the displacement has reached the maximum value, and the maximum amount of relative displacement of the energy absorbing member 4 is determined by the position of the joint (the farther the position of the joint is from the curved part 4a, the smaller the area of the fixed part 4c is. (The maximum amount of relative displacement of the energy absorbing member 4 becomes large).

In this example, as shown in FIG. 1, a pair of energy absorbing members 4 are arranged with their curved portions 4a facing each other (with the curved portions 4a closest to each other or in contact with each other). It is preferable to leave an interval of, for example, 5 to 10 mm between the curved parts 4a in consideration of deformation of the curved parts 4a, but it is also possible to provide no interval. In addition, when the energy absorbing members 4 are provided as a pair, they can also be arranged so that the fixing parts 4c face each other (so that the fixing parts 4c are closest to each other or in contact with each other). Further, the length dimension of the energy absorbing member 4 (single body, not a pair) can be, for example, 250 to 400 mm, and the height dimension (dimension from one contact surface to the other contact surface) and width. The dimensions can be, for example, 50 to 150 mm.

A pair of energy absorbing members 4 are provided so that the curved portions 4a face each other (so that the curved portions 4a are close to each other or in contact with each other), and the length of the pair of energy absorbing members 4 (the length of the pair of energy absorbing members 4) is A pair of members each having an abutment surface (a clamping part) having a dimension equal to the dimension from the end of one of the fixed parts 2c on the same side of the absorbent part 4 to the end of the other fixed part 2c. It is held between. As a comparison, as shown in FIG. 4A, when a pair of energy absorbing members 4 are arranged with their fixing parts 4c facing each other, a pair of energy absorbing members 4 having contact surfaces (clamping parts) as long as the pair of energy absorbing members 4 are arranged. Even if the members are clamped from both sides, as schematically shown in Figure 4B, the vertical restraining force is lost when the relative displacement occurs, resulting in locally uneven bending strain that differs from the original bending strain. This tends to cause deformation due to bending strain, and there is a risk that the original function of absorbing energy cannot be fully exerted due to relative displacement of the pair of opposing parts. On the other hand, as shown in FIG. 3A, by arranging the pair of energy absorbing members 4 with their curved portions 4a facing each other, as shown schematically in FIG. 3B, when a relative displacement occurs, Also, since the energy absorbing member 4 is always constrained by the abutment surfaces of the pair of members, the deformation with the same bending strain as the initial bending strain is maintained, and as a result, energy is not sufficiently absorbed. Therefore, the shaking of the building can be attenuated even more quickly. Moreover, according to such a configuration, the space required for installing the energy absorbing member 4 can also be minimized.

The energy absorbing member 4 is connected to the upper deck beam or the lower deck beam directly or via the attachment member 3. The mounting member 3 includes a pair of rod-shaped members 3a and 3b, and a connecting member 3c having an abutment surface (a clamping portion) to which the energy absorbing member 4 is joined. The pair of rod-shaped members 3a and 3b are made of square steel pipes. Further, the connecting member 3c is a member having a substantially T-shaped cross section and having a rectangular plate-shaped horizontal piece and a rectangular plate-shaped hanging piece that hangs down from the horizontal piece. The upper surface of the horizontal piece serves as an abutment surface, and a hole for bolting the energy absorbing member 2 is bored therein. One end of the pair of rod-shaped members 3a and 3b is joined to both ends of the connecting member 3c by welding or the like, and the mounting member 3 as a whole has a substantially isosceles trapezoid shape when viewed from the front.

The mounting member 3 hangs down from the upper floor beam 5 or stands up from the lower floor beam 6 by joining the other ends of the pair of rod-shaped members 3a and 3b to the upper floor beam 5 or the lower floor beam 6 by bolting or the like. ing. The mounting member 3 is designed to prevent interstory displacement between a pair of abutting surfaces when interstory displacement (horizontal relative displacement between the upper floor beam 5 and the lower floor beam 6) occurs in the frame due to horizontal force such as an earthquake. The energy absorbing member 4 is deformed by causing a relative displacement according to the energy absorbing member 4. The greater the rigidity of the mounting member 3, the more effectively it deforms the energy absorbing member 4, but the mounting member 3 only needs to have enough rigidity to cause the energy absorbing member 4 to deform, and does not need to be a completely rigid body.

The form shown in FIG. 1(a) uses a pair of mounting members 3 to dispose an energy absorbing member 4 approximately in the middle between an upper floor beam and a lower floor beam, and a contact surface of the pair of mounting members 3. This is an example in which the parts are brought into contact with each other (a pair of clamping parts) and joined by bolt joints. Furthermore, in the embodiments shown in FIGS. 1(b) and 1(c), the energy absorbing member 4 is placed near the upper floor beam or the lower floor beam using only one mounting member 3, and the energy absorbing member 4 is placed near the upper floor beam or the lower floor beam. This is an example in which the abutting surface (one clamping part) contacts the flange surface (the other clamping part) of the lower deck beam or the upper deck beam and is joined by bolt connection. In either form, relative horizontal displacement occurs between the pair of fixed pieces 2c of the energy absorbing member 4 corresponding to the interstory displacement (relative displacement in the horizontal direction between the upper floor beam and the lower floor beam), and It can absorb energy such as

[Second embodiment]
FIG. 5 is a front view showing an earthquake-resistant structure according to a second embodiment of the present invention. The second embodiment shown in FIG. 5 differs from the first embodiment shown in FIG. 1 in that a pair of columns 7 and 8 are arranged on both sides of the energy absorption member 4 in the horizontal direction ( , FIG. 1(a) and FIG. 5(a), FIG. 1(b) and FIG. 5(b), and FIG. 1(c) and FIG. 5(c), respectively).
The columns 7 and 8 are each made of square steel pipes, and their upper ends are joined to the upper floor beam 5 by bolts or the like, and their lower ends are joined to the lower floor beam 6 by bolts or the like.
The other ends of the pair of rod-like members 2a and 2b are joined to the side surfaces of the pillars 7 and 8, respectively, by bolts or the like.
With this configuration, the upper floor beam 5 and the lower floor beam 6 are connected by the columns 7 and 8, and vertical deformation of the upper floor beam 5 and the lower floor beam 6 is suppressed, so interstory displacement is transmitted more directly to the energy absorbing member 4, and the energy absorbing effect of the energy absorbing member 4 can be further enhanced.

[Third embodiment]
FIG. 6 is a front view showing an earthquake-resistant structure according to a third embodiment of the present invention. The explanation of the same configuration as the second embodiment will be omitted, and the different points will be explained below. In the form of FIG. 6(a), the pair of attachment members 3 are arranged in the left-right direction, and the energy absorbing member 4 is arranged to extend in the up-down direction. Each attachment member 3 extends in the direction of one column from the other column. The rod-shaped members 3a and 3b of each mounting member 3 are joined to the side surface of the column by bolting or the like. In the form of FIGS. 6(b) and 6(c), the mounting member 3 extends from one pillar to the vicinity of the other pillar, and its contact surface (one clamping part) is on the side surface of the other pillar. The energy absorbing members 4 are arranged so as to extend in the vertical direction. One fixed part 4c of the energy absorbing member 4 is directly joined to the vertically intermediate side surface (the other clamping part) of the other column by bolting or the like, and the other fixed part 4c is connected to the contact surface of the mounting member 3. are connected by bolts, etc. In any of the embodiments shown in FIGS. 6(a) to 6(c), a plurality of energy absorbing members 4 may be installed in a line in the vertical direction.

[Fourth embodiment]
FIG. 7 is a front view showing an earthquake-resistant structure according to a fourth embodiment of the present invention. In the fourth embodiment shown in FIG. 7, a pair of pillars 7 and 8 are arranged relatively close to each other (for example, the distance between opposing side surfaces is about 20 to 30 cm). Further, in the energy absorbing member 4, the pair of fixing parts 4c are directly abutted on the side surfaces (pair of clamping parts) of the pair of pillars 7 and 8, respectively, and are joined by bolt joints or the like. The energy absorbing member 4 is configured so that a plurality of pairs of energy absorbing members 4 can be installed continuously in the vertical direction on a pair of pillars 7 and 8 (holes for bolt connection are formed in advance at predetermined positions on the side surfaces of the pillars). perforated). The energy absorbing members 4 are installed in pairs (two pieces) as one unit. The number of pairs of energy absorbing members 4 to be installed is determined depending on the required horizontal strength (for example, only one pair may be used).

[Fifth embodiment]
FIG. 8 is a front view showing an earthquake-resistant structure according to a fifth embodiment of the present invention. The mounting member 3 includes a first contact piece having a contact surface that comes into contact with the side surface of the column, and a second contact piece that has a contact surface (pinching part) that comes into contact with the fixing part 4c of the energy absorbing member 4. It is composed of an abutting piece and a connecting piece made of a substantially isosceles trapezoidal plate interposed between the first abutting piece and the second abutting piece. The second abutting piece is configured such that a plurality of pairs of energy absorbing members 4 can be installed continuously in the vertical direction (holes for bolt connection are previously drilled at predetermined positions). The energy absorbing members 4 are installed in pairs (two pieces) as one unit. The number of pairs of energy absorbing members 4 to be installed is determined depending on the required horizontal strength (for example, only one pair may be used).

FIG. 9 is a diagram showing an example of an energy absorbing member. Here, the energy absorbing member 4 has a curved portion, a pair of intermediate portions that extend continuously from both ends of the curved portion, and a pair of fixed portions that extend continuously from the ends of the pair of intermediate portions. Preferably, the layers are stacked one on top of the other. This is because seismic performance can be further improved. Here, by adjusting the number of stacked layers, the thickness of each layer, etc., the seismic performance of each energy absorbing member 4 can be easily adjusted. In the illustrated example, a configuration in which three layers 41, 42, and 42 are stacked is shown, but two or more layers may be used. The upper limit of the number of layers is not particularly limited as long as it is within a processable range. Here, the thicknesses t1, t2, and t3 of each layer are not particularly limited, but can be determined so that the bending strain of each layer is approximately the same. In addition, assuming that the bending strain, which greatly affects the energy absorption capacity, is the same, by using multiple layers, the material volume becomes smaller and space can be saved.
Here, as shown in FIG. 9, when a member with a thickness t is bent with an outer radius r, the bending strain ε is:
(Formula) ε=(t/2)/(rt/2)
Defined by
As an example, when r=88mm and t=16mm,
ε=(t/2)/(rt/2)=(16/2)/(88-16/2)=8/80=0.1
Therefore, the bending strain is 0.1 (10%).
Note that the area S1 per unit length in the depth direction is
S1=(88 ² -72 ² )×π/2≒4021.24mm ² /mm
becomes.
On the other hand, if there are two layers, the outer thickness t2 = 12 mm and the inner thickness t1 = 9 mm, the bending strain of the outer layer is:
ε=(t/2)/(rt/2)=(12/2)/(66-12/2)=6/60=0.1
Therefore, it is 10%.
The bending strain of the inner layer is
ε=(t/2)/(rt/2)=(9/2)/(54-9/2)=4.5/49.5
=0.091
This is 9.1%.
Therefore, compared to the case of a single layer with t = 16 mm, in the case of the above two layers, the bending strain of both the outer layer and the inner layer is equal to or less than that of the case of a single layer with t = 16 mm. You can expect repeatable performance.
On the other hand, the area S2 per unit length in the depth direction in the case of the above two layers is
S2=(66 ² -45 ² )×π/2≒3661.53mm ² /mm
So, S2/S1=3661.53/4021.24≒0.91
Therefore, the material volume is 91%. In this way, it is possible to reduce the material volume with the same seismic performance (energy absorption capacity).

Here, it is preferable that the thickness of the inner layer of at least two of the plurality of layers in the energy absorbing member is thinner than the thickness of the outer layer. This makes it possible to reduce the difference in bending strain between the inner layer and the outer layer, suppress early fatigue of the inner layer, and reduce the processing of the inner layer. This is because it becomes easier. For similar reasons, it is particularly preferred that the innermost layer has the thinnest thickness. Furthermore, for the same reason, as shown in FIG. 9, it is preferable that the layer thickness of the energy absorbing member is thinner as the inner layer is closer to the bending strain center of the curved portion (the example of FIG. 9). Then, t1<t2<t3). Here, it is preferable that the energy absorbing member is in a state in which a plurality of layers are welded and integrated. This is because on-site construction becomes easier. It is preferable that the energy absorbing member has a stepped portion formed by two layers adjacent to each other in the stacking direction having different lengths, and is integrated by fillet welding at the stepped portion. This is because an energy absorbing member as shown in FIG. 9 can be easily manufactured. For example, as shown in FIG. 10A (front view), the length of the inner layer is shorter than that of the outer layer, and it is possible to perform fillet welding (shown in black) at the resulting step to integrate the inner layer. can. Alternatively, as shown in Figure 10B (side view), a shorter layer can be sandwiched between longer layers, and the step can be integrated by fillet welding (shown in black). I can do it. Alternatively, as shown in FIG. 10C (side view), a hole may be provided in the outer layer and a fillet weld (shown in black) may be applied to the periphery of the hole. Here, as an example, in a building whose seismic performance is to be improved, a plurality of layers having the same external dimensions and having the above-mentioned curved part, the above-mentioned pair of intermediate parts, and the above-mentioned pair of fixed parts are provided. A process of preparing multiple types of energy absorbing members formed by stacking layers, each having a different number of layers and/or layer thickness, and setting one or more installation parts in the building where the energy absorbing members can be installed. a step of calculating the horizontal load borne by each energy absorbing member in the building; and a step of selecting the type of energy absorbing member to be installed in the installation part from among the above multiple types based on the calculated horizontal load. A building can be seismically designed by a method that includes the following steps: According to such a method, the positions where the energy absorbing members are installed can be concentrated, and the degree of freedom in designing the floor plan increases. Furthermore, even if the seismic performance is improved by changing the number and thickness of the layers of energy-absorbing materials, the external dimensions remain the same regardless of the number and thickness of the layers of energy-absorbing materials. The installation parts of the members can always be placed in the same space.

1: Earthquake-resistant structure,
3: Mounting member,
4: Energy absorbing member,
5: Upper floor beam (upper horizontal member),
6: Lower floor beam (lower horizontal member),
7: Pillar,
8: Pillar

Claims (5)

An upper horizontal member, a lower horizontal member, and a pair of energy absorbing members provided between the upper horizontal member and the lower horizontal member,
The energy absorbing member includes a curved portion, a pair of intermediate portions that extend continuously from both ends of the curved portion, and a pair of fixed portions that continuously extend from the ends of the pair of intermediate portions. , the pair of fixed portions is configured to undergo relative displacement in the extending direction in response to relative displacement in the horizontal direction between the upper horizontal member and the lower horizontal member;
The pair of energy absorbing members are held in close proximity by a pair of holding parts, with the curved parts facing each other,
Earthquake-resistant, which is held by the holding parts having a dimension equal to the dimension from the end of one of the fixed parts on the same side of the pair of energy absorbing members to the end of the other fixed part. structure. An upper horizontal member, a lower horizontal member, and a pair of energy absorbing members provided between the upper horizontal member and the lower horizontal member,
The energy absorbing member includes a curved portion, a pair of intermediate portions that extend continuously from both ends of the curved portion, and a pair of fixed portions that continuously extend from the ends of the pair of intermediate portions. , the pair of fixed portions is configured to undergo relative displacement in the extending direction in response to relative displacement in the horizontal direction between the upper horizontal member and the lower horizontal member;
The pair of energy absorbing members are held in close proximity by a pair of holding parts, with the curved parts facing each other,
having a holding part that can continuously hold a plurality of pairs of the pair of energy absorbing members;
The seismic structure is such that the pair of clamping parts are configured to allow a plurality of pairs of the energy absorbing members to be installed continuously in the vertical direction. An upper horizontal member, a lower horizontal member, and a pair of energy absorbing members provided between the upper horizontal member and the lower horizontal member,
The energy absorbing member includes a curved portion, a pair of intermediate portions that extend continuously from both ends of the curved portion, and a pair of fixed portions that continuously extend from the ends of the pair of intermediate portions. , the pair of fixed portions is configured to undergo relative displacement in the extending direction in response to relative displacement in the horizontal direction between the upper horizontal member and the lower horizontal member;
The pair of energy absorbing members are held in close proximity by a pair of holding parts, with the curved parts facing each other,
The energy absorbing member has an earthquake-resistant structure that is composed of multiple layers, and the thickness of the inner layer is smaller than the thickness of the outer layer. The earthquake-resistant structure according to claim 1 or 2, wherein the energy absorbing member is composed of multiple layers, and the thickness of the inner layer is smaller than the thickness of the outer layer. The earthquake-resistant structure according to claim 3, further comprising a holding portion that can continuously hold a plurality of pairs of the pair of energy absorbing members .

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