Vibration control structure

Abstract

To provide a vibration control structure that can suppress excessive deformation of a connection portion and reduce response when seismic loads or wind loads act on it.SOLUTION: A vibration control structure has a connection portion 4 that connects a lower structure 2 and an upper structure 3. A seismic isolation bearing 41 that connects the lower structure 2 and the upper structure 3 in a horizontal direction in a relative displaceable manner, a rotating inertia mass damper 5 that is connected to the lower structure 2 and the upper structure 3 and generates a reaction force proportional to the relative acceleration between the lower structure 2 and the upper structure 3, and a switching portion that switches the rotating inertia mass damper 5 between a movable state and an immovable state are provided in the connection portion 4. The secondary stiffness of the connection portion 4 is set to a value higher than the optimum stiffness for the lower structure 2 and the upper structure 3 to synchronize in an initial state. When the relative acceleration between the lower structure 2 and the upper structure 3 reaches a dynamic state exceeding a predetermined value or equal to or higher than the predetermined value, it is set to be closer to the optimum stiffness than the initial state by the reaction force generated by the rotating inertia mass damper 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration damping structure. [Background technology]

[0002] In recent years, a vibration control structure (building mass damper) has been put into practical use in which a connecting section (seismic isolation layer) consisting of laminated rubber bearings and dampers is provided on the upper floors of a building, and the upper structure above the connecting section and the lower structure below the connecting section are synchronized like a TMD (dynamic vibration absorber) during earthquakes or strong winds to suppress shaking of the entire building (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-127169 A Summary of the Invention [Problem to be solved by the invention]

[0004] Building mass dampers also deform in the connection parts when wind loads act on them, so it is necessary to restore the residual deformation. If optimal stiffness based on fixed-point theory is used in the connection parts of building mass dampers so that the substructure and superstructure are synchronized, the static components of the wind load alone may cause the connection parts to deform by about 1m in the extremely rare event of a strong wind. If the connection parts deform by about 1m, it may be difficult to ensure the safety of elevators that pass through the connection parts. In addition, if laminated rubber bearings are provided in the connection parts, there is a risk that the laminated rubber will be damaged if the connection parts deform by about 1m. For this reason, building mass dampers impart stiffness three or four times higher than the optimal stiffness for TMD to the connection parts to suppress excessive deformation of the connection parts. However, a building mass damper with a stiffness three or four times higher than the optimal stiffness for TMD in the connection parts has a smaller response reduction effect than a building mass damper with an optimal stiffness in the connection parts.

[0005] Lead plug laminated rubber bearings and steel dampers are often used in the connecting parts. When a large earthquake or strong winds cause the connecting parts to deform significantly, the lead plug laminated rubber bearings and steel dampers become plastic and absorb the energy, but there is a possibility that residual deformation will occur after the earthquake or strong winds have subsided. If residual deformation occurs in the connecting parts, it may cause problems in the operation of the elevators that pass through the connecting parts.

[0006] Therefore, an object of the present invention is to provide a vibration control structure that can suppress excessive deformation of connecting parts and reduce response when earthquake loads or wind loads are applied. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the vibration control structure of the present invention has a lower substructure in a structure, an upper structure in the structure higher than the lower structure, and a connecting portion connecting the lower structure and the superstructure, the connecting portion being provided with a seismic isolation bearing connecting the lower structure and the superstructure to allow relative displacement in the horizontal direction, a rotational inertia mass damper connected to the lower structure and the superstructure and generating a reaction force proportional to the relative acceleration between the lower structure and the superstructure, and a switching portion switching the rotational inertia mass damper between a movable state and an immobile state, the secondary stiffness of the connecting portion being set to a value higher than the optimal stiffness at which the lower structure and the superstructure are in harmony in an initial state, and being set so that when the relative acceleration between the lower structure and the superstructure exceeds a predetermined value or reaches a dynamic state equal to or greater than a predetermined value, the reaction force generated by the rotational inertia mass damper brings the secondary stiffness closer to the optimal stiffness than in the initial state.

[0008] Since a rotational inertia mass damper generates a reaction force proportional to the relative acceleration between the lower structure and the superstructure, a reaction force is generated against dynamic components of wind loads and earthquake loads where the external force changes in a short period of time and the relative acceleration exceeds a predetermined value, but no reaction force or almost no reaction force is generated against static components of wind loads where the external force is nearly constant and the relative acceleration is very small. For this reason, in the present invention, in a static state in which the static component of the wind load acts on the superstructure, the secondary rigidity of the connection part becomes higher than the optimal rigidity for the lower structure and superstructure to be in harmony, and deformation of the connection part can be suppressed. In a dynamic state in which the dynamic component of the wind load or earthquake load acts on the superstructure, the reaction force generated by the rotational inertia mass damper causes the secondary rigidity of the connection part to approach the optimal rigidity for the lower structure and superstructure to be in harmony, and therefore the superstructure and lower structure can be synchronized, thereby reducing the response of the structure. The present invention also has a switching unit that switches the rotary inertia mass damper between a movable state and a stationary state. Therefore, for example, even when a wind load acts and the structure becomes dynamic, the rotary inertia mass damper can be immobilized to maintain the secondary stiffness of the connecting portion at a value higher than the optimal stiffness at which the lower structure and the upper structure are in tune with each other as in the initial state, and deformation of the connecting portion can be suppressed. In this way, for example, when an elevator is provided penetrating the connecting portion, the rotary inertia mass damper can be switched to the stationary state by the switching unit in strong winds to suppress deformation of the connecting portion, thereby preventing the elevator from stopping operation in strong winds. The switching unit can be used as a wind-resistant lock that restricts relative displacement between the lower structure and the upper structure.

[0009] In addition, in the vibration control structure of the present invention, the rotational inertial mass damper may include a rotating weight that rotates due to horizontal relative displacement between the lower structure and the upper structure and generates an inertial mass, a cylinder connected to one of the lower structure and the upper structure and filled with hydraulic oil, a piston rod connected to the other of the lower structure and the upper structure and inserted into the cylinder so as to be able to move back and forth, a piston attached to the piston rod and dividing the cylinder into two oil chambers, and a hydraulic motor that is coaxially connected to the rotating weight and connected to each of the two oil chambers via connecting pipes, and rotates by the hydraulic pressure of the hydraulic oil flowing through the connecting pipes.

[0010] With this configuration, the rotation can be amplified by the hydraulic motor without increasing the size of the rotary weight of the rotary inertia mass damper, so that the inertial mass generated by the rotation of the rotary weight can be increased.

[0011] In the vibration damping structure according to the present invention, the switching portion may be a solenoid valve capable of switching between opening and closing of the connecting pipe.

[0012] With this configuration, the rotary inertia mass damper can be reliably and easily switched between a movable state and a stationary state.

[0013] In the vibration damping structure according to the present invention, either the piston or the connecting pipe may be provided with a relief valve.

[0014] With this configuration, overloading of the rotary inertia mass damper can be prevented.

[0015] In the vibration control structure according to the present invention, the rotary inertia mass damper may have a restoring mechanism for restoring residual deformation of the connecting portion.

[0016] With this configuration, there is no need to provide a jack or the like for returning the residual deformation of the connecting portion to its original state. Effect of the Invention

[0017] According to the present invention, excessive deformation of the connecting portion can be suppressed, and the response can be reduced when an earthquake load or a wind load is applied. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating an example of a vibration damping structure according to an embodiment. [Diagram 2] 4 is a mass point model showing an example of a vibration damping structure according to an embodiment. [Diagram 3] The restoring characteristics of the connection. [Figure 4] FIG. 13 is a diagram showing the load-deformation relationship of a connecting portion to which a rotational inertia mass damper is added. [Diagram 5] FIG. 2 illustrates a rotary inertial mass damper. [Figure 6]FIG. 1A is a diagram showing the switching section in an unlocked state, and FIG. 1B is a diagram showing the switching section in a locked state. [Figure 7] FIG. 1(a) is a diagram showing an oscillating weight with a handle attached, FIG. 1(b) is a diagram showing a hydraulic motor and the flow of hydraulic oil, and FIG. 1(c) is a diagram showing the operation of the restoration mechanism. [Figure 8] 13 is a graph showing a resonance curve when a rotary inertia mass damper is added. [Figure 9] 13 is a graph showing the restoring force characteristics of a connecting portion. [Figure 10] 13 is a graph showing resonance curves of systems with different coupling part specifications. [Figure 11] 1 is a table showing the specifications and cases of the connecting parts. [Figure 12] This is a graph of maximum response (inter-story drift angle). [Figure 13] This is a graph of maximum response (story shear force). [Figure 14] 1 is a graph of maximum response value (absolute acceleration). [Figure 15] 13 is a graph of maximum response (story displacement). [Figure 16] 1 is a graph of maximum response value (overturning moment). [Figure 17] This is a graph of maximum response value (inter-story deformation). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, a vibration damping structure according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1 and FIG. 2, the vibration control structure 1 according to this embodiment is adopted in a building 11 (structure) such as a high-rise building or a skyscraper. The vibration control structure 1 has a substructure 2, an upper structure 3, and a connecting portion 4. The substructure 2 corresponds to the lower floors of the building 11. The substructure 2 is supported by the ground. The upper structure 3 corresponds to the upper floors of the building 11. The connecting portion 4 is a seismic isolation layer provided between the substructure 2 and the upper structure 3, and connects the substructure 2 and the upper structure 3 so as to be displaceable relative to each other in the horizontal direction. The vibration control structure 1 is a building mass damper structure that suppresses the shaking of the entire building by synchronizing the substructure 2 and the upper structure 3 like a TMD (dynamic vibration absorber) during an earthquake or strong wind. The connecting portion 4 in this embodiment is provided above the 1 / 2 height position of the building 11.

[0020] The connecting portion 4 is provided with a seismic isolation bearing 41 and a rotational inertia mass damper 5. The seismic isolation bearing 41 is provided between the substructure 2 and the superstructure 3. The seismic isolation bearing 41 in this embodiment is a laminated rubber bearing. The laminated rubber bearing is, for example, a natural rubber laminated rubber bearing, a lead plug laminated rubber bearing, a high damping laminated rubber bearing, or the like. The seismic isolation bearing 41 may be a sliding bearing, a rolling bearing, or the like, instead of a laminated rubber bearing. In addition to the seismic isolation bearing 41 and the rotational inertia mass damper 5, the connecting portion 4 may be provided with an oil damper or a steel damper.

[0021] The rotational inertia mass damper 5 is provided between the lower structure 2 and the upper structure 3. The rotational inertia mass damper 5 has a rotary weight 51 that rotates due to the horizontal relative displacement between the lower structure 2 and the upper structure 3. The rotational inertia mass damper 5 is provided with a switching unit 52 (see FIG. 5) that switches between a movable state in which the rotary weight 51 can rotate and an immobile state in which the rotary weight 51 does not rotate. The rotational inertia mass damper 5 generates a reaction force in proportion to the relative acceleration between the lower structure 2 and the upper structure 3. For this reason, the rotational inertia mass damper 5 generates a reaction force against dynamic components of wind loads and earthquake loads in which the external force changes in a short time and the relative acceleration exceeds a predetermined value, but generates no reaction force or almost no reaction force against static components of wind loads in which the external force is almost constant and the relative acceleration is minute. A state in which the dynamic components of wind loads and earthquake loads act on the upper structure 3 is referred to as a "dynamic state", and a state in which the static components of wind loads act on the upper structure 3 is referred to as a "static state". In the dynamic state, the relative acceleration between the lower structure 2 and the upper structure 3 exceeds a predetermined value or is equal to or greater than a predetermined value, and in the static state, the relative acceleration between the lower structure 2 and the upper structure 3 is less than a predetermined value or is equal to or less than a predetermined value. The rotational inertia mass damper 5 will be described in detail later.

[0022] In addition to the seismic isolation bearing 41 and the rotary inertia mass damper 5, the connecting portion 4 of this embodiment may be provided with a damping material 42 that suppresses excessive deformation of the seismic isolation layer caused by an earthquake exceeding the seismic motion that occurs extremely rarely. The damping material 42 is, for example, a variable stiffness damper that does not act in the deformation region of the seismic isolation layer caused by seismic motion below a certain magnitude, but acts only in an extremely large earthquake or wind load that exceeds the certain magnitude.

[0023] Mass of lower structure 2 (M L ) for the mass of superstructure 3 (M U ) ratio (μ=M U / M L ) is 0.1 or more and 1.0 or less. In a static state, the restoring force characteristic of the connecting part 4 is nonlinear. The nonlinear restoring force characteristic of the connecting part 4 is treated as a bilinear model, and the elastic range is expressed as the first-order stiffness (K ISO,1 ), and the gradient of the stiffness after plasticization is the secondary stiffness (K ISO,2) is set. There are various ways to determine the gradient of the secondary stiffness of the connecting part 4 when forming a bilinear model. In this embodiment, as shown in FIG. 3, the gradients of the lines a and b are determined so that the area of ​​region A surrounded by the curve c showing the restoration characteristics of the connecting part 4 and the line a in the elastic range is equivalent to the area of ​​region B surrounded by the curve c showing the restoration characteristics of the connecting part 4 and the line b in the range after plasticization. In order to suppress deformation of the connecting part 4 in strong winds, the secondary stiffness (K ISO,2 ) is calculated by the fixed point theory. OPT ) is larger than (K ISO,2 >K OPT ).

[0024] Optimal stiffness (K OPT ) is expressed by the following equation (1). K OPT =M U λ 2 ω L 2 …(1) Here, the mass of the superstructure 3: M U Mass of lower structure 2: M L Mass ratio:μ=M U / M L Optimal frequency ratio: λ=1 / (1+μ) Natural circular frequency of substructure 2: ω L Natural circular frequency of the superstructure 3 including the connecting part 4: ω U

[0025] Furthermore, the coupling damping (h ISO ) is also the optimal damping (h OPT ), and in order to suppress excessive response deformation due to fluctuation components during earthquakes and strong winds, the optimal damping (h OPT ) has been awarded more than half of the Connection damping (h ISO )>Optimal damping (h OPT ) / twenty two) Here, h ISO =√{3 / 8·μ / (1+μ)}

[0026] Specifically, the viscous damping coefficient (C ISO ) is expressed by the following equation (3). C ISO >2×h ISO / 2×K ISO / ω U …(3) Viscous damping is provided by viscous dampers such as oil dampers and high damping rubber. For oil dampers with a relief mechanism, the primary viscous damping coefficient is the target.

[0027] In the initial state, the secondary stiffness of the connecting portion 4 is set to a value greater than the optimum stiffness at which the lower structure 2 and the upper structure 3 are in harmony. Even in a static state, the secondary stiffness of the connecting portion 4 is greater than the optimum stiffness at which the lower structure 2 and the upper structure 3 are in harmony. In contrast, as shown in FIG. 4, in a dynamic state, the pseudo mass (M d ) is added, the effect of negative stiffness (-ω 2 M d ), the secondary stiffness of the connecting part 4 is set to a value closer to the optimal stiffness than in the static state (initial state). In FIG. 4, the graph on the left shows the static state, the graph on the right shows the dynamic state, and the graph in the center shows the effect of negative stiffness (-ω 2 M d ) In other words, the secondary stiffness of the connecting part 4 in the dynamic state is K ISO,2 -ω2·M d As shown in the following equation (4), the optimal stiffness (K OPT ) is set to a value close to K OPT ≒K ISO,2 -ω2·M d …(4)

[0028] When the secondary stiffness of the connecting part 4 is set to a value close to the optimal stiffness in a dynamic state, the tuning effect of the building mass damper (vibration control structure 1) can be improved. However, the secondary stiffness of the connecting part 4 in a dynamic state does not necessarily need to be close to the optimal stiffness. ISO,2 In the resonance curve drawn as above, it is sufficient that the maximum value of the response magnification is lower than that in the static state.

[0029] 5, the rotational inertia mass damper 5 has a rotary weight 51, a switching unit 52, a cylinder 53, hydraulic oil 54, a piston rod 55, a piston 56, a connecting pipe 57, a hydraulic motor 58, and a restoring mechanism 59. The rotational inertia mass damper 5 of this embodiment is configured to generate an inertial mass using the hydraulic motor 58. The rotational inertia mass damper 5 may also be configured to generate an inertial mass using a ball screw mechanism.

[0030] The cylinder 53 is connected to either the lower structure 2 or the upper structure 3 (see Figures 1 and 2). Hydraulic oil 54 is sealed in the cylinder 53. The piston rod 55 is connected to the other of the lower structure 2 and the upper structure 3. The piston rod 55 is inserted into the cylinder 53 so as to be movable back and forth. The axes of the cylinder 53 and the piston rod 55 extend horizontally. The piston 56 is attached to the middle part of the piston rod 55 in the axial direction. The piston 56 is inserted into the cylinder 53 together with the piston rod 55 so as to be movable in the axial direction. The piston 56 divides the interior of the cylinder 53 into two oil chambers 531, 532.

[0031] The connecting pipe 57 is connected to each of the two oil chambers 531, 532 of the cylinder 53. The hydraulic oil 54 of the cylinder 53 flows through the connecting pipe 57. When the cylinder 53 and the piston 56 are displaced relative to each other in the axial direction and one of the two oil chambers 531, 532 becomes higher pressure than the other, the hydraulic oil 54 in one oil chamber flows into the connecting pipe 57, and the hydraulic oil 54 in the connecting pipe 57 flows into the other oil chamber. That is, a flow of the hydraulic oil 54 is formed in the connecting pipe 57. The hydraulic motor 58 rotates by the force of the hydraulic oil 54 flowing through the connecting pipe 57. The rotary weight 51 is coaxially connected to the hydraulic motor 58. That is, when the lower structure 2 and the upper structure 3 are displaced relative to each other in the horizontal direction and the cylinder 53 and the piston 56 are displaced relative to each other in the horizontal direction, a flow of the hydraulic oil 54 is formed in the connecting pipe 57, and the hydraulic motor 58 rotates, causing the rotary weight 51 to rotate. The rotation of the rotary weight 51 generates an inertial mass.

[0032] The switching unit 52 is a solenoid valve provided on the connecting pipe 57. As shown in Figs. 6(a) and (b), the switching unit 52 switches the connecting pipe 57 between an open state (unlocked state) and a closed state (locked state) by moving the valve body 521. The switching unit 52 switches the rotational inertia mass damper 5 to a movable state by opening the connecting pipe 57, and switches the rotational inertia mass damper 5 to a stationary state by closing the connecting pipe 57. The switching unit 52 is operated by a signal from the outside. When the switching unit 52 switches the rotational inertia mass damper 5 to a stationary state, the relative displacement between the lower structure 2 and the upper structure 3 is restrained, and deformation of the connecting part 4 can be suppressed. For example, when the switching unit 52 switches the rotational inertia mass damper 5 to a stationary state during a strong wind, deformation of the connecting part 4 due to the strong wind can be suppressed. The building 11 is provided with a detection unit that detects the action of a major earthquake or strong wind, and is set to send a signal to the switching unit 52 to switch the rotary inertia mass damper 5 to a movable state when the detection unit detects a major earthquake or a wind that exceeds expectations. Also, when the detection unit detects a wind that falls within expectations, it is set to send a signal to the switching unit 52 to switch the rotary inertia mass damper 5 to a non-movable state. Note that the rotary inertia mass damper 5 is provided with a relief valve (not shown) in either the piston 56 or the connecting pipe 57 to prevent overload of the inertia mass due to the rotation of the rotor 51.

[0033] The restoring mechanism 59 restores the residual deformation of the connecting part 4. The restoring mechanism 59 has a handle 591 attached to the oscillating weight 51. The manager can rotate the oscillating weight 51 around its axis by gripping and rotating the handle 591. When residual deformation occurs in the connecting part 4 and the lower structure 2 and the upper structure 3 are disposed in a position displaced from the initial position, the handle 591 is rotated to rotate the oscillating weight 51, thereby rotating the shaft 581 of the hydraulic motor 58, and the gears 582 and 583 linked with the rotation of the shaft 581 forcibly move the hydraulic oil 54 in the connecting pipe 57 to relatively displace the cylinder 53 and the piston 56, and the lower structure 2 and the upper structure 3 are returned to their initial positions, thereby restoring the residual deformation of the connecting part 4. The restoring mechanism 59 may be an electric tool such as a motor that generates torque to rotate the oscillating weight 51 instead of the handle 591.

[0034] Next, the effect of the vibration damping structure according to this embodiment will be described. In the vibration control structure 1 according to this embodiment, in a static state in which the static component of the wind load acts on the superstructure 3, the secondary stiffness of the connecting part 4 is higher than the optimal stiffness at which the substructure 2 and the superstructure 3 are in harmony, thereby suppressing deformation of the connecting part 4. In a dynamic state in which the dynamic component of the wind load or the earthquake load acts on the superstructure 3, the reaction force generated by the rotational inertia mass damper 5 causes the secondary stiffness of the connecting part 4 to approach the optimal stiffness at which the substructure 2 and the superstructure 3 are in harmony, thereby synchronizing the substructure 2 and the superstructure 3 and reducing the response of the building 11. The vibration-damping structure 1 according to this embodiment also has a switching unit 52 that switches the rotational inertia mass damper 5 between a movable state and a stationary state. For this reason, even when a wind load acts and the structure becomes dynamic, the rotational inertia mass damper 5 can be immobilized to maintain the secondary stiffness of the connecting portion 4 at a value higher than the optimal stiffness at which the lower structure 2 and the upper structure 3 are in tune with each other as in the initial state, and deformation of the connecting portion 4 can be suppressed. For example, when an elevator is provided penetrating the connecting portion 4, the rotational inertia mass damper 5 can be switched to the stationary state by the switching unit 52 in strong winds to suppress deformation of the connecting portion 4, thereby preventing the elevator from stopping operation in strong winds. The switching unit 52 can be used as a wind-resistant lock that restricts the relative displacement between the lower structure 2 and the upper structure 3.

[0035] The vibration damping structure 1 according to the present embodiment is configured to generate inertial mass by utilizing the hydraulic motor 58. With such a configuration, the rotation can be amplified by the hydraulic motor 58 without enlarging the rotary weight 51 of the rotational inertial mass damper 5, and therefore the inertial mass generated by the rotation of the rotary weight 51 can be increased.

[0036] In the vibration control structure 1 according to the present embodiment, the switching unit 52 is a solenoid valve that can switch between opening and closing the connecting pipe 57. With this configuration, the rotary inertia mass damper 5 can be reliably and easily switched between the immobile state and the movable state.

[0037] In the vibration control structure 1 according to this embodiment, a relief valve is provided in either the piston 56 or the connecting pipe 57. This configuration makes it possible to prevent overload of the rotary inertia mass damper 5. Furthermore, in the unlikely event that a malfunction occurs in the switching part 52 and the switching part 52 is subjected to a major earthquake or unexpectedly strong winds while remaining immobile, the connecting part can still move.

[0038] In the vibration control structure 1 according to this embodiment, the rotary inertia mass damper 5 has a restoration mechanism 59 that restores the residual deformation of the connecting part 4. By adopting such a configuration, it is not necessary to provide a jack or the like for restoring the residual deformation of the connecting part 4.

[0039] In the vibration control structure 1 of this embodiment, the multi-functional rotational inertia mass damper 5 combines all of the functions of periodic synchronization at the connecting parts 4, which are essential for a building mass damper, prevention of excessive deformation in strong winds, wind-resistant locking to improve livability, and restoration of residual deformation after an earthquake, in a single damper, thereby enabling the device to be consolidated, resulting in a space-saving and economical building mass damper.

[0040] In the vibration control structure of this embodiment, even if a rigidity about 3 to 4 times the optimal rigidity is added to suppress deformation of the connecting part in strong winds, tuning is improved by adding a rotational inertia mass damper 5 to the connecting part 4, the maximum value of the response magnification of the resonance curve is reduced, and the response during earthquakes and strong winds can also be reduced. Figure 8 shows the resonance curve when the stiffness of the connecting part is linear and three times the optimal value, the resonance curve when the rotational inertia mass damper 5 is added with a pseudo mass equal to that of the superstructure, and the resonance curve when there is no building mass damper with no seismic isolation layer. It can be seen from Figure 8 that the addition of the rotational inertia mass damper 5 improves the tuning state and reduces the maximum value of the response magnification.

[0041] Below, we compare the response of a building mass damper (vibration control structure 1) that uses a connection part (connection part 4) with nonlinear restoring force characteristics on the 25th floor of a 46-story building with and without the addition of a rotational inertia mass damper 5.

[0042] The period of the lower structure is about 3.2 seconds. The primary effective mass of the lower structure is M L = 104,000 tons. The primary effective mass of the superstructure is M U = 99000 tons. Mass ratio μ = M U / M L = 99000 / 104000 = 0.95. Therefore, the optimum stiffness of the joint, K OPT = 100,000 kN / m. Here, using the above formula (1), it can be expressed as follows. K OPT =M U λ 2 ω L 2 =99000×(1 / (1+0.95)) 2 ×(2π / 3.2) 2 ≒100,000kN / m The mass of the superstructure is: M U Mass of the lower structure: M L Mass ratio:μ=M U / M L Optimal frequency ratio: λ=1 / (1+μ)

[0043] The stiffness of the connecting part 4 is set to a secondary stiffness K which is about four times the optimal stiffness in order to suppress excessive deformation during strong winds. ISO,2 The primary natural period of the entire building 11 calculated using the secondary stiffness of the connecting part 4 at this time is 6.9 seconds. Figure 9 shows the restoring force characteristics.

[0044] The negative stiffness of the rotational inertia mass damper 5 reduces the secondary stiffness K ISO,2 The optimum stiffness K OPT In order to approach the negative stiffness (ω 2 M d ) can be added to the connecting portion 4. ω 2 M d =400-100=300kN / mm From ω=2π / 6.9=0.91, M d =300,000 / (0.91) 2 ≒360,000 tons Therefore, a rotary inertia mass damper 5 of 360,000 ton is provided at the connecting portion 4. The damping coefficient of the connecting portion 4 was set to 60,000 kNs / m and was applied linearly.

[0045] FIG. 10 shows a resonance curve when the specifications of the connecting part 4 are linear. The resonance curves in FIG. 10 are shown for three cases shown in FIG. 11. In case 1, the rotary inertia mass damper 5 is not added, and the stiffness of the connecting part 4 is set to a secondary stiffness K K , which is about four times the optimal stiffness. ISO,2 In case 2, the rotational inertia mass damper 5 is not added, and the stiffness of the connecting part 4 is set to the optimum stiffness. In case 3, the rotational inertia mass damper 5 is added, and the stiffness of the connecting part 4 is set to a secondary stiffness K ISO,2 From Fig. 10, it can be seen that Case 3, in which the stiffness of the connecting part 4 is four times the optimal stiffness and the rotational inertia mass damper 5 is added, is closer to the optimal tuning (Case 2) than Case 1, in which the stiffness of the connecting part 4 is four times the optimal stiffness and the rotational inertia mass damper 5 is not added.

[0046] Using these parameters, response analysis results for story drift angle, story shear force, absolute acceleration, story displacement, overturning moment, and story deformation for Case 1 (without rotational inertia mass damper) and Case 3 (with rotational inertia mass damper) above are shown in Figures 12 to 17. The input earthquake motion was notification wave Level 2 (Hachinohe EW phase). In both response analyses, the cases where rotational inertia mass dampers 5 were added showed improved synchronization and increased deformation at connectors 4 compared to the cases where they were not added (see the 25th story in the graph showing the response of story drift angle in Figure 12 and the 25th story in the graph showing the response of story deformation in Figure 17), while the maximum response values ​​for other story shear forces, absolute acceleration, story displacement, and overturning moment were reduced.

[0047] Although the embodiment of the vibration damping structure according to the present invention has been described above, the present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, a relief valve is provided in either piston 56 or connecting pipe 57 of rotary inertia mass damper 5, but this need not necessarily be the case. Rotary inertia mass damper 5 may be provided with a mechanism other than the relief valve that can prevent overload of rotary inertia mass damper 5.

[0048] In the above embodiment, the rotational inertia mass damper 5 is equipped with a restoration mechanism 59 that restores residual deformation of the connecting part 4. If a jack or the like is provided for restoring residual deformation of the connecting part 4, the rotational inertia mass damper 5 does not need to be equipped with a restoration mechanism 59.

[0049] Although the connecting portion 4 in this embodiment is provided above half the height of the building 11, the height at which the connecting portion 4 is provided may be set appropriately. In the connecting portion 4 of this embodiment, in addition to the seismic isolation bearing 41 and the rotary inertia mass damper 5, a damping material 42 is provided to suppress excessive deformation of the seismic isolation layer caused by earthquakes exceeding the seismic motion, which occurs extremely rarely, but this is not necessarily required.

[0050] The Sustainable Development Goals (SDGs) are among the 17 international goals adopted at the United Nations Summit in September 2015. The vibration control structure of this embodiment can contribute to achieving the 17 SDGs goals, such as goal 11, "Sustainable cities and communities." [Explanation of symbols]

[0051] 1. Vibration-damping structure 2 Substructure 3 Superstructure 4 Connecting part 11 Buildings (structures) 41 Seismic isolation bearing 51 Oscillating weight 52 Switching section 53 Cylinder 54 Hydraulic oil 55 Piston rod 56 Piston 57 Connecting pipe 58 Hydraulic Motor 59 Restoration mechanism

Claims

1. a lower substructure of the structure; an upper structure of the structure that is higher than the lower structure; a connecting portion that connects the lower structure and the upper structure, The connecting portion has a seismic isolation bearing that connects the lower structure and the upper structure so as to be displaceable relative to each other in a horizontal direction; a rotary inertial mass damper connected to the lower structure and the upper structure and generating a reaction force proportional to a relative acceleration between the lower structure and the upper structure; a switching unit that switches the rotary inertia mass damper between a movable state and a stationary state, The secondary rigidity of the connection portion is In the initial state, the stiffness is set to a value higher than the optimum stiffness at which the lower structure and the upper structure are tuned to each other, A vibration control structure in which, when the relative acceleration between the lower structure and the upper structure exceeds a predetermined value or reaches a dynamic state equal to or greater than a predetermined value, the reaction force generated by the rotational inertia mass damper is set to approach the optimal stiffness more than the initial state.

2. The rotary inertial mass damper comprises: a rotating weight that rotates due to a horizontal relative displacement between the lower structure and the upper structure to generate an inertial mass; a cylinder connected to either the lower structure or the upper structure and filled with hydraulic oil; a piston rod connected to the other of the lower structure and the upper structure and inserted into the cylinder so as to be capable of moving forward and backward; a piston attached to the piston rod and dividing the cylinder into two oil chambers; 2. The vibration damping structure according to claim 1, further comprising: a hydraulic motor that is coaxially connected to the rotary spindle and connected to each of the two oil chambers via connecting pipes, and rotates by the hydraulic pressure of the hydraulic oil flowing through the connecting pipes.

3. The vibration damping structure according to claim 2 , wherein the switching portion is an electromagnetic valve capable of switching between opening and closing of the connecting pipe.

4. 4. The vibration damping structure according to claim 2, wherein either the piston or the connecting pipe is provided with a relief valve.

5. The vibration damping structure according to claim 1 , wherein the rotary inertia mass damper has a restoring mechanism for restoring residual deformation of the connecting portion.

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