Building with low stiffness floor

Abstract

To provide a building having the same function as a base-isolated building, and that can be constructed relatively inexpensively.SOLUTION: A building 1 includes a sub structure 2, an upper structure 3, a low rigidity layer 4 arranged between the sub structure 2 and the upper structure 3, and a vibration control device 5. Columns of the low rigidity layer 4 are formed of low rigidity columns 10 having lower flexural rigidity than upper columns 7 of the upper structure 3. A lower beam 6 provided at an upper end of the sub structure 2, an upper beam 8 provided at a lower end of the upper structure 3, and the low rigidity columns 10 form a rigid frame structure 12. The vibration control device 5 is installed to the rigid frame structure 12. Although the rigid frame structure 12 deforms at an earthquake due to the low flexural rigidity of the low rigidity columns 10, excessive deformation is prevented by the vibration control device 5. A non-damage vibration region where the rigid frame structure 12 causes elastic vibration becomes remarkably large by the low rigidity columns 10, whereby the low rigidity layer 4 exerts the function equal to a base isolation layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a building having a low stiffness layer provided with a vibration control device so as to have a function similar to that of a seismic isolation layer. [Background technology]

[0002] Seismic isolation buildings that reduce the response acceleration and inter-story displacement of the superstructure compared to earthquake-resistant buildings by providing a seismic isolation layer equipped with a seismic isolation device such as laminated rubber bearings between the substructure such as the foundation and the superstructure are becoming widespread (for example, Patent Document 1). Non-Patent Document 1 describes the speculation that in pilotis-type buildings, by increasing the deformation capacity by using circular hoops in the pilotis columns made of reinforced concrete, the columns function as seismic isolation devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-096501 A [Non-patent literature]

[0004] [Non-Patent Document 1] "Concrete Engineering Vol. 58, No. 5", Japan Concrete Institute, May 2020, pp. 346-352 Summary of the Invention [Problem to be solved by the invention]

[0005] In a seismic isolation layer using conventional seismic isolation devices such as laminated rubber bearings, the cost of constructing the seismic isolation layer is high due to the fact that the laminated rubber bearings themselves are expensive, many seismic isolation devices are required to be installed under almost all columns of the superstructure, and footings and foundation beams are required above and below the seismic isolation devices, etc. Furthermore, in the invention described in Non-Patent Document 1, there was a demand for the development of a means to ensure the deformation capacity of larger columns and prevent excessive deformation.

[0006] In view of these problems, the present invention aims to provide a building that has the same functions as a seismically isolated building and can be constructed relatively inexpensively. [Means for solving the problem]

[0007] A building (1) according to one embodiment of the present invention is characterized in that it comprises a lower structure (2) including a lower beam (6) provided at an upper end, an upper structure (3) including a plurality of upper columns (7) and an upper beam (8) provided at a lower end and joined to the upper columns (7), a low-rigidity layer (4) arranged between the lower structure (2) and the upper structure (3), the low-rigidity layer (4) including low-rigidity columns (10, 61) having a bending rigidity lower than that of the upper columns (7) and joined to the lower beams (6) and the upper beams (8) to form a rigid frame structure (12) together with the lower beams (6) and the upper beams (8), and a vibration control device (5, 31, 41, 51) attached to the rigid frame structure (12) and configured to suppress displacement of the upper beams (8) relative to the lower beams (6) in the rigid frame structure (12) during an earthquake.

[0008] With this structure, the rigid frame structure deforms significantly during an earthquake because the low-rigidity columns have low bending rigidity, but the vibration control device prevents excessive deformation of the rigid frame structure, so the low-rigidity layer functions similarly to a seismic isolation layer. In addition, the building can be constructed relatively inexpensively because it does not use relatively expensive seismic isolation devices such as laminated rubber.

[0009] In one embodiment of the present invention, in the above-mentioned configuration, the low-rigidity columns (6, 61) include a first low-rigidity column (10a, 61a) joined to one of the lower beam (6) and the upper beam (8) to form a first joint corner portion (21), and a second low-rigidity column (10b, 61b) joined to the one of the upper beam (6) and the lower beam (8) to form a second joint corner portion (23), and the vibration control device (5, 31, 41, 51) includes a seesaw member (20, 32, 42) attached to the other of the lower beam (6) and the upper beam (8) via a pin joint body (19) so as to be rotatable around an axial direction perpendicular to a structural plane including the rigid frame structure (12), and a vibration control device (5, 31, 41, 51) having one end that is rotatable around the axial direction perpendicular to the structural plane including the rigid frame structure (12). the other end of which is joined to the seesaw member (20, 32, 42) so as to be rotatable around the axis, and the other end of which is joined to the first joint corner (21) so as to be rotatable around the axis; a second tie rod (24, 52) the one end of which is joined to the seesaw member (20, 32, 42) so as to be rotatable around the axis, and the other end of which is joined to the second joint corner (23) so as to be rotatable around the axis; and a damper (25) attached to the seesaw member (20, 32, 42) and the other of the lower beam (6) and the upper beam (8) to suppress rotation of the seesaw member (20, 32, 42) around the axis.

[0010] According to this configuration, the vibration control device can be manufactured at a relatively low cost, and since it is only necessary to install one per structural face, construction costs can be reduced.

[0011] One embodiment of the present invention is characterized in that, in a direct-above configuration, the vibration control device (5, 31, 41, 51) is disposed on the exterior surface of the building (1).

[0012] According to this configuration, the inside of the low rigidity layer can be effectively utilized.

[0013] One embodiment of the present invention is characterized in that, in the above-mentioned second or third configuration, the lower structure (2) is a foundation structure, the other of the lower beam (6) and the upper beam (8) is the lower beam (6), and the lower beam (6) is a foundation beam.

[0014] The member to which the seesaw member of the vibration control device is attached via a pin joint is subjected to large forces from the seesaw member and the damper, but with this configuration, the seesaw member is attached to the foundation beam, which is already strong, so there is no need to reinforce the lower beam to attach the seesaw member.

[0015] In one embodiment of the present invention, in any of the above configurations, the low-rigidity columns (10, 61) are made of unbonded prestressed concrete.

[0016] According to this configuration, the bending rigidity of the low rigidity columns can be reduced, and the non-damage vibration region in which the rigid frame structure elastically vibrates becomes significantly larger.

[0017] One embodiment of the present invention is characterized in that in the direct above configuration, the lower ends of the low stiffness columns (61) that join the lower beam have a narrower cross-section than the portion directly above and / or contain fewer main reinforcements (13) than the portion directly above.

[0018] With this configuration, the bending rigidity of the low rigidity column can be further reduced.

[0019] One embodiment of the present invention is characterized in that, in the above-mentioned fifth or sixth configuration, the plurality of low-rigidity columns (10, 61) include a steel or fiber-reinforced plastic restraining member (18) that abuts against the outer surface of the concrete portion (15) around its entire circumference, and / or includes steel or resin fibers within the concrete portion.

[0020] According to this configuration, a confining effect is obtained by the restraining member or fiber, and the concrete portion can be prevented from collapsing.

[0021] One embodiment of the present invention is characterized in that in any of the above configurations except for the configuration in which the low-rigidity columns are made of unbonded prestressed concrete, the multiple upper columns (7) are made of steel frame, and the multiple low-rigidity columns (10) are made of steel frame having a smaller cross-section than the multiple upper columns (7).

[0022] With this configuration, in a steel-framed building, it is possible to construct low-rigidity columns with lower bending rigidity than the upper columns.

[0023] In one embodiment of the present invention, in any of the above configurations, the low-rigidity columns (10, 61) have a height equivalent to one or more stories in the upper structure.

[0024] According to this configuration, the low-rigidity columns are longer, so that the vibration period of the low-rigidity layer can be lengthened, and the inside of the low-rigidity layer can be utilized effectively. Effect of the Invention

[0025] According to the present invention, it is possible to provide a building having a low-rigidity layer that has the same function as a seismic isolation layer, can be constructed relatively inexpensively, and has sufficient deformation capacity. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a front view of a building according to an embodiment; [Diagram 2] FIG. 1 is a front view showing a modified example of a building according to an embodiment; [Diagram 3] FIG. 1 is a cross-sectional view showing a low-rigidity column of a building according to an embodiment. [Figure 4] FIG. 11 is a front view showing a first modified example of a vibration damping device according to an embodiment; [Diagram 5] FIG. 11 is a front view showing a second modified example of the vibration damping device according to the embodiment; [Figure 6] FIG. 13 is a front view showing a third modified example of the vibration damping device according to the embodiment; [Figure 7] FIG. 1 is a front view showing a modified example of a low-rigidity column according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, a building 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the building 1 includes a lower structure 2, an upper structure 3, a low-rigidity layer 4 disposed between the lower structure 2 and the upper structure 3, and a vibration control device 5 disposed within the low-rigidity layer 4. In the example shown in Fig. 1, the low-rigidity layer 4 is provided in the aboveground portion, but as shown in Fig. 2, the low-rigidity layer 4 may be provided in the underground portion.

[0028] 1 and 2, the substructure 2 is a foundation structure constructed on the ground, and a lower beam 6, which is a foundation beam, is provided at the upper end of the substructure 2. The substructure 2 may include the lower floor portion of the building 1 in addition to the foundation structure, and in this case, the beam provided at the upper end of the lower floor portion becomes the lower beam 6.

[0029] The upper structure 3 includes a plurality of upper columns 7, an upper beam 8 provided at the lower end of the upper structure 3 and joined to the plurality of upper columns 7, and a plurality of upper beams 9 provided above the upper beam 8 and joined to the plurality of upper columns 7.

[0030] The low-rigidity layer 4 is joined at its lower end to the lower beam 6 and at its upper end to the upper beam 8, and includes a plurality of low-rigidity columns 10 having lower bending rigidity than the plurality of upper columns 7, and an inner-story beam 11 joined to the middle parts of the plurality of low-rigidity columns 10. The lower beam 6, the upper beam 8, and the low-rigidity columns 10 form a rigid frame structure 12. The plurality of low-rigidity columns 10 are arranged on one exterior surface of the building 1, beside The low-rigidity layer 4 includes a first low-rigidity column 10a arranged at one end in the vertical direction, a second low-rigidity column 10b arranged at the other end, and a third low-rigidity column 10c arranged between the first low-rigidity column 10a and the second low-rigidity column 10b. The low-rigidity columns 10 are preferably arranged on an extension line of the multiple upper columns 7. The illustrated low-rigidity layer 4 has a two-story structure, but the low-rigidity layer 4 may be a one-story structure without an intralayer beam 11, or a three or more story structure with multiple intralayer beams 11 at different positions in the vertical direction.

[0031] The column-beam structure of the building 1 is made of reinforced concrete. The column-beam structure of the building 1 may be constructed using precast concrete members, cast-in-place concrete, or a combination of both. When using precast concrete members, large precast concrete members may be used to reduce the labor required for construction and improve productivity, or divided precast concrete members may be used to reduce weight and enable lifting with a relatively small crane. The low-rigidity columns 10 are made of unbonded prestressed concrete to have a lower bending rigidity than the upper columns 7, and are preferably thinner than the upper columns 7.

[0032] As shown in Fig. 3, each of the low-rigidity columns 10 includes a plurality of main reinforcements 13 extending in the vertical direction, a plurality of ties 14 extending in the horizontal direction so as to surround the plurality of main reinforcements 13, a concrete portion 15 in which the main reinforcements 13 and ties 14 are embedded, and a tendon 16 not attached to the concrete portion 15. It is preferable to use a PC steel rod as the tendon 16, but a PC steel wire, a PC steel strand, or the like may also be used. The tendon 16 is inserted into a hole 17 extending in the vertical direction in the concrete portion 15, and is fixed to both the upper and lower ends of the low-rigidity column 10 under a tensile force, thereby applying prestress to the low-rigidity column 10.

[0033] Each of the low-rigidity columns 10 preferably further includes a restraining member 18, such as a steel sheet or steel pipe, or a sheet made of fiber-reinforced plastic, such as carbon fiber or aramid fiber, that abuts the outer surface of the concrete portion 15 over the entire circumference. Although a large compressive force is applied to the concrete portion 15 of the low-rigidity column 10, the restraining member 18 provides a confining effect, thereby preventing the concrete portion 15 from collapsing. Instead of or in addition to the restraining member 18, the concrete portion 15 may include steel fibers or resin fibers to obtain a confining effect.

[0034] The column-beam structure of the building 1 may be a steel frame structure instead of a reinforced concrete structure. In this case, the low-rigidity columns 10 have a smaller cross section than the upper columns 7, and therefore have a lower bending rigidity than the upper columns 7.

[0035] Hereinafter, the direction perpendicular to the structural plane including the rigid frame structure 12 having the first and second low-rigidity columns 10a, 10b (the direction perpendicular to the paper surface of FIGS. 1 and 2) will be referred to as the "axial direction". As shown in Figures 1 and 2, the vibration control device 5 is a device equipped with a so-called oscillating vibration control mechanism, and includes a seesaw member 20 attached to the lower beam 6 via a pin joint 19 so as to be rotatable around the axial direction, a first tie rod 22 having one end joined to the seesaw member 20 so as to be rotatable around the axial direction and the other end joined to a first joint corner 21 formed by the upper end of the first low-rigidity column 10a and one end of the upper beam 8 so as to be rotatable around the axial direction, a second tie rod 24 having one end joined to the seesaw member 20 so as to be rotatable around the axial direction and the other end joined to a second joint corner 23 formed by the upper end of the second low-rigidity column 10b and the other end of the upper beam 8 so as to be rotatable around the axial direction, and a pair of dampers 25 attached to the seesaw member 20 and the lower beam 6 to suppress rotation of the seesaw member 20 around the axial direction. The first and second tie rods 22, 24 cross each other above the pin joint body 19, and their lower ends are joined to both ends of the seesaw member 20. The intersection position of the first and second tie rods 22, 24 is located closer to the lower beam 6 than the center between the lower beam 6 and the upper beam 8. The first and second tie rods 22, 24 are joined to the first and second joint corners 21, 23 via gusset plates 26 (see FIG. 4).

[0036] The pin joint 19 is fixed to the lower beam 6 and supports the seesaw member 20 rotatably around the axial direction. The pin joint 19 may be constituted by, for example, a clevis.

[0037] The seesaw member 20 includes a long member that extends approximately parallel to the extending direction of the lower beam 6 during non-earthquakes, and a steel material such as a shaped steel can be used as the long member.

[0038] The first and second tie rods 22, 24 include steel rods having both ends formed into a fork shape so that they can be pin-joined to other members. Instead of being composed of a single steel rod, each of the first and second tie rods 22, 24 may include two steel rods having distal ends formed into a fork shape and a turnbuckle 27 (see FIG. 4) connecting the ends of the two steel rods that are close to each other. It is preferable that the lengths of the first and second tie rods 22, 24 are approximately equal to each other, and that the angles of the first and second tie rods 22, 24 with respect to the upper beam 8 are approximately equal to each other. It is preferable that a tensile force is introduced in advance to both the first and second tie rods 22, 24 so that a tensile force is applied to both the first and second tie rods 22, 24 during a non-earthquake.

[0039] The pair of dampers 25 are arranged to sandwich the pin joint 19, and are fixed at their lower ends to the lower beam 6 and at their upper ends near both ends of the seesaw member 20 in the extension direction. The dampers 25 are vibration dampers, and are, for example, hysteretic dampers such as steel dampers, oil dampers, or viscoelastic dampers. The pair of dampers 25 may be the same or different. The pair of dampers 25 apply damping forces in the vertical direction to both ends of the seesaw member 20.

[0040] The vibration control device 5 acts to suppress deformation of the rigid frame structure 12 during an earthquake. The following description focuses on the rectangular rigid frame structure 12 that is composed of the lower beam 6, the upper beam 8, and the first and second low-rigidity columns 10a, 10b.

[0041] When the upper beam 8 receives a seismic force (inertia force) toward the right in FIG. 1 relative to the lower beam 6 during an earthquake, the upper beam 8 moves while maintaining a parallel state to the lower beam 6 so that the multiple low-rigidity columns 10 are tilted and / or curved to the right, and the rectangular rigid frame structure 12 is deformed. In the deformed rigid frame structure 12, the diagonal line connecting the upper right corner and the lower left corner becomes longer and the diagonal line connecting the upper left corner and the lower right corner becomes shorter compared to before the deformation. Since the diagonal line connecting the upper right corner and the lower left corner of the rigid frame structure 12 becomes longer, a tensile force is generated in the second tie rod 24, and this tensile force acts on the rigid frame structure 12 in a direction that resists the seismic force. In addition, the tensile force generated in the second tie rod 24 rotates the seesaw member 20 clockwise around the axis direction. This rotation widens the distance between the parts where both ends of the first tie rod 22 are joined, that is, the distance between the first joint corner 21 and one end of the seesaw member 20 (the right end in FIG. 1). The increase in the distance between the first joint corner 21 and the right end of the seesaw member 20 due to this rotation is roughly equal to the decrease in length in the direction in which the first tie rod 22 is compressed due to the shortening of the diagonal line connecting the upper left corner and the lower right corner of the rigid frame structure 12, so that the length of the first tie rod 22 remains roughly the same as its length during non-earthquake, and the application of compressive force to the first tie rod 22 is suppressed.

[0042] Subsequently, when the direction of earthquake vibration changes and the upper beam 8 is subjected to a seismic force toward the left in Figure 1 relative to the lower beam 6, even while the low-rigidity column 10 is returning from its right-side inclined and / or curved state to a vertical state, a tensile force is generated in the first tie rod 22 due to the damping force from the damper 25, and this tensile force acts on the rigid frame structure 12 in a direction to resist the seismic force.

[0043] When the low-rigidity column 10 is tilted and / or curved to the left, the diagonal line connecting the upper left corner and the lower right corner of the deformed rigid frame structure 12 becomes longer and the diagonal line connecting the upper right corner and the lower left corner becomes shorter compared to before the deformation. Since the diagonal line connecting the upper left corner and the lower right corner of the rigid frame structure 12 becomes longer, a tensile force is generated in the first tie rod 22, and this tensile force acts on the rigid frame structure 12 in a direction to resist the earthquake force. In addition, the tensile force generated in the first tie rod 22 rotates the seesaw member 20 counterclockwise around the axis. This rotation widens the distance between the portion where both ends of the second tie rod 24 are joined, i.e., between the second joint corner 23 and the other end of the seesaw member 20 (the left end in FIG. 1). The increase in the distance between the second joint corner 23 and the left end of the seesaw member 20 due to this rotation is roughly equal to the decrease in length in the direction in which the second tie rod 24 is compressed due to the shortening of the diagonal line connecting the upper right corner and the lower left corner of the rigid frame structure 12, so that the length of the second tie rod 24 remains roughly the same as its length during non-earthquake, and the application of compressive force to the second tie rod 24 is suppressed.

[0044] Subsequently, when the direction of earthquake vibration changes and the upper beam 8 is subjected to a seismic force toward the right in Figure 1 relative to the lower beam 6, even while the low-rigidity column 10 is returning from its inclined and / or curved state to the left to its vertical state, a tensile force is generated in the second tie rod 24 due to the damping force from the damper 25, and this tensile force acts on the rigid frame structure 12 in a direction to resist the seismic force.

[0045] The vibration control device 5 repeats the above-mentioned movements during an earthquake, thereby preventing excessive deformation of the rigid frame structure 12.

[0046] Because the low-stiffness columns 10 are made of unbonded prestressed concrete, strain generation in the tendons 16 made of PC steel bars that resist bending moments is suppressed, reducing the bending stiffness of the low-stiffness columns 10. Because the low-stiffness columns 10 have lower bending stiffness than the upper columns 7, the undamaged vibration region in which the rigid frame structure 12 elastically vibrates becomes significantly larger, and the low-stiffness layer 4 performs the same function as a seismic isolation layer. In addition, by attaching the vibration control devices 5 to the rigid frame structure 12, excessive deformation of the rigid frame structure 12 can be prevented.

[0047] In the low stiffness column 10, a confining effect is obtained by the restraining member 18 and / or the fibers contained within the concrete portion 15, thereby preventing the concrete portion 15 from collapsing.

[0048] The vibration control device 5 can be manufactured at a relatively low cost, and since it is sufficient to install one per structural face, the construction cost is lower than that of seismic isolation layers using laminated rubber bearings, etc., which have a high unit price, require a large number of units, and require the construction of a foundation for installation. In addition, the low-rigidity layer 4 can be made almost maintenance-free.

[0049] By disposing the vibration control device 5 on the exterior surface, the inside of the low-rigidity layer 4 can be effectively utilized. For example, the low-rigidity layer 4 can be utilized as a parking lot, a facility and machinery room, or a water supply facility. Also, by having the low-rigidity column 10 have a height of one or more stories in the upper structure 3, the inside of the low-rigidity layer 4 can be effectively utilized.

[0050] The vibration control device 5 includes a seesaw member 20 and first and second tie rods 22, 24 joined to the seesaw member 20, and thereby concentrates the displacement of each layer spanned by the first and second tie rods 22, 24 to one location. The seesaw member 20 switches horizontal displacement to vertical displacement, and reduces the effect of the compression side of the first and second tie rods 22, 24. In other words, the seesaw member 20 works to allow the vibration control device 5 to concentrate the deformation of the low-rigidity layer 4, which functions as a seismic isolation layer, to one location, without considering the prevention of buckling of the first and second tie rods 22, 24. In addition, the vibration control device 5 absorbs the vibration energy of an earthquake by the dampers 25.

[0051] By taking into consideration the weight of the low-rigidity layer 4 and the length of the low-rigidity column 10, the period of the entire building 1 can be lengthened, and the building 1 has a vibration reduction effect equivalent to that of a seismic isolation construction method, despite being a vibration control construction method.

[0052] The lower beam 6 is required to have a corresponding strength since a large force is applied from the vibration control device 5. The foundation beams of foundation structures are large due to the need for underground pits and the like. By using such a strong foundation beam as the lower beam 6, increases in construction costs can be suppressed. In addition, the lower beam 6, which is a foundation beam, appropriately transmits the concentrated reaction force from the vibration control device 5 to the ground or pile body (not shown).

[0053] 4 to 6 show first to third modified examples of the vibration damping device 5 in the above embodiment. The vibration damping devices 31, 41 according to the first and second modified examples shown in Figs. 4 and 5 differ from the above embodiment in the shapes of the seesaw members 32, 42. The vibration damping device 51 according to the third modified example shown in Fig. 6 differs from the above embodiment in that the second tie rod 52 includes a cross turnbuckle 53. In the explanation, configurations that are common or similar to those in the above embodiment are given the same reference numerals and explanations will be omitted.

[0054] The seesaw member 32 of the vibration damping device 31 shown in FIG. 4 is composed of a triangular frame material in which three long members are rigidly connected at their ends, and the surface defined by the triangular frame is parallel to the structural surface of the rigid frame structure 12 (see FIG. 1) including the first and second low-rigidity columns 10a, 10b. Steel materials such as shaped steel may be used as the long members. The seesaw member 32 may be considered as a rigid body against earthquake forces acting in the left-right and up-down directions of the structural surface on which it is installed, and may be composed of other shapes and / or other materials as long as it has a left-right length and a up-down length, for example, it may be formed of a triangular steel panel material when viewed from the front. The triangular seesaw member 32 is preferably an isosceles triangle, with the base disposed horizontally and a pair of equal sides disposed so as to approach each other upward from both ends of the base.

[0055] The lower ends of the first and second tie rods 22, 24 are joined to the triangular seesaw member 32 near the apex of the upper part of the triangular seesaw member 32 so as to be rotatable about the axis. This joining point is preferably aligned with the pin joint 19 in the vertical direction, and its vertical position is closer to the lower beam 6 than the center between the lower beam 6 and the upper beam 8 (see FIG. 1) and above the rotation axis of the pin joint 19. During non-earthquakes, the first and second tie rods 22, 24 are preferably arranged on the extensions of the members constituting the sides extending from the apex of the upper part of the triangular seesaw member 32.

[0056] Even with this configuration, the vibration damping device 31 has the same effects as the vibration damping device 5 of the above embodiment.

[0057] The seesaw member 42 of the vibration damping device 41 shown in Figure 5 has an inverted Y shape when viewed from a direction perpendicular to the structural surface on which the vibration damping device 41 is installed, and is formed by rigidly joining one ends of three long steel members such as structural steel members together by welding or fastening with fasteners (not shown).

[0058] The rotation axis of the pin joint 19 is located above the joint between the seesaw member 42 and the damper 25 .

[0059] The seesaw member 42 may have a shape other than an inverted Y-shape as long as it can be regarded as a rigid body against earthquake forces acting in the left-right and up-down directions on the structural plane on which the vibration control device 41 is installed, has a length in the left-right direction and the up-down direction, and has a shape that allows the rotation axis of the pin joint 19 to be positioned above the connection between the seesaw member 42 and the damper 25. For example, the seesaw member 42 may have a shape that is modified such that the center of the lower side is concave upward compared to the shape of the seesaw member 32 of the first modified example (see FIG. 4).

[0060] By positioning the rotation axis of the pin joint 19 above the connection between the seesaw member 42 and the damper 25, the distance between the rotation axis of the pin joint 19 and the connection parts of the first and second tie rods 22, 24 to the seesaw member 42 is shortened. If the displacement of this connection part during an earthquake is the same, the shorter the distance between them, the larger the rotation angle of the seesaw member 42. Therefore, the displacement of the damper 25 can be amplified more than in the first embodiment without increasing the length of the seesaw member 42 in the left-right direction. This improves the energy absorption efficiency of the vibration control device 41.

[0061] The inverted Y-shaped seesaw member 42 has an inwardly concave inverted Y shape compared to the triangular seesaw member 32 of the first modified example, so that the space in the concave portions on the left and right sides can be effectively utilized. For example, this space can be used as installation space for a jack or the like for introducing tensile force into the first and second tie rods 22, 24.

[0062] 6, in a vibration damping device 51 according to the third modification, a second tie rod 52 includes a cross turnbuckle 53. The cross turnbuckle 53 has a through hole 54 through which the first tie rod 22 is inserted. By inserting the first tie rod 22 into the through hole 54, the first and second tie rods 22, 52 can be arranged on approximately the same plane.

[0063] FIG. 7 shows a low-rigidity column 61 according to a modified example. As in the above embodiment, the low-rigidity column 61 includes a first low-rigidity column 61a arranged at one end, a second low-rigidity column 61b arranged at the other end, and a third low-rigidity column 61c arranged between the first low-rigidity column 61a and the second low-rigidity column 61b on the exterior surface. The low-rigidity column 61 is of unbonded prestressed concrete construction, and in addition, at the lower end joined to the lower beam 6, it has a narrower cross section than the part directly above it, and / or includes fewer main reinforcements 13 than the part directly above it. For this reason, the low-rigidity column 61 becomes more likely to swing around the column base as an axis, and the bending rigidity becomes even lower.

[0064] Although the description of the specific embodiment is finished above, the present invention is not limited to the above embodiment and can be widely modified and implemented. The vibration control device may be arranged upside down. That is, a seesaw member may be attached to the upper beam via a pin joint, the upper ends of the first and second tie rods may be joined to the seesaw member, and the lower ends may be joined to the joint corners between the first and second low-rigidity columns and the lower beam. The vibration control device may be installed on the interior structure surface instead of the exterior structure surface, and the first and second low-rigidity columns may be low-rigidity columns arranged in the middle part of the structure surface instead of the left and right ends. As the vibration control device, a known vibration control device other than a device having a swing vibration control mechanism, such as a hysteretic stiffness damper, a viscous damper, or a brace-type oil damper, may be used. [Explanation of symbols]

[0065] 1: Building 2: Lower structure 3:Superstructure 4: Low rigidity layer 5, 31, 41, 51: Vibration control device 6: Lower beam 7: Upper pillar 8: Upper beam 10,61:Low rigidity column 10a, 61a: 1st low rigidity column 10b, 61b: 2nd low rigidity column 12: Frame structure 13: Main reinforcement 15: Concrete part 16: Tensile material 18: Restraint member 19: Pin joint 20, 32, 42: Seesaw members 21: 1st joint corner 22: First tie rod 23:Second joint corner 24,52: Second tie rod 25: Damper

Claims

1. A lower structure including a lower beam provided at an upper end; An upper structure including a plurality of upper columns and an upper beam provided at a lower end and joined to the upper columns; a low-rigidity layer disposed between the lower structure and the upper structure, the low-rigidity layer having a bending rigidity lower than that of the upper column and including a low-rigidity column joined to the lower beam and the upper beam to form a rigid frame structure together with the lower beam and the upper beam; a vibration control device attached to the rigid frame structure and configured to suppress displacement of the upper beam relative to the lower beam in the rigid frame structure during an earthquake; Equipped with The plurality of low-rigidity columns include a first low-rigidity column joined to one of the lower beam and the upper beam to form a first joint corner, and a second low-rigidity column joined to the one of the upper beam and the lower beam to form a second joint corner, The vibration damping device is a seesaw member attached to the other of the lower beam and the upper beam via a pin joint so as to be rotatable about an axis perpendicular to a structural face including the rigid frame structure; a first tie rod having one end joined to the seesaw member so as to be rotatable about the axial direction and having the other end joined to the first joint corner portion so as to be rotatable about the axial direction; a second tie rod having one end joined to the seesaw member so as to be rotatable about the axial direction and having the other end joined to the second joint corner portion so as to be rotatable about the axial direction; a damper attached to the seesaw member and the other of the lower beam and the upper beam to suppress rotation of the seesaw member about the axial direction; A building comprising:

2. The building according to claim 1 , wherein the vibration control device is disposed on an exterior surface of the building.

3. The lower structure is a foundation structure, the other of the lower beam and the upper beam is the lower beam, The building according to claim 1 or 2, characterized in that the lower beam is a foundation beam.

4. The building according to any one of claims 1 to 3, characterized in that the plurality of low-rigidity columns are made of unbonded prestressed concrete.

5. The building described in claim 4, characterized in that the lower ends of the multiple low-rigidity columns that join to the lower beam have a narrower cross-section than the portion immediately above and / or contain fewer main reinforcement bars than the portion immediately above.

6. The building described in claim 4 or 5, characterized in that the multiple low-rigidity columns include a restraining member made of steel or fiber-reinforced plastic that abuts the outer surface of the concrete portion around its entire circumference, and / or includes steel or resin fibers within the concrete portion.

7. The upper columns are made of steel, The building according to any one of claims 1 to 3, characterized in that the plurality of low-rigidity columns are of steel frame construction having a smaller cross section than the plurality of upper columns.

8. The building described in any one of claims 1 to 7, characterized in that the multiple low-rigidity columns have a height of one or more stories in the upper structure.

9. A lower structure including a lower beam provided at an upper end; An upper structure including a plurality of upper columns and an upper beam provided at a lower end and joined to the upper columns; a low-rigidity layer disposed between the lower structure and the upper structure, the low-rigidity layer having a bending rigidity lower than that of the upper column and including a low-rigidity column joined to the lower beam and the upper beam to form a rigid frame structure together with the lower beam and the upper beam; a vibration control device attached to the rigid frame structure and configured to suppress displacement of the upper beam relative to the lower beam in the rigid frame structure during an earthquake; Equipped with The low stiffness columns are made of unbonded prestressed concrete, A building characterized in that the multiple low-rigidity columns include a restraining member made of steel or fiber-reinforced plastic that abuts the outer surface of the concrete portion around its entire circumference, and / or includes steel or resin fibers within the concrete portion.

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