JP2011106136A - Vertical vibration control system of base-isolated building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical vibration control system being applicable to a base-isolated building having a three-dimensional base isolation structure and capable of reducing vibration, in particular, in the vertical direction effectively and properly. <P>SOLUTION: A three-dimensional base isolation device 3 for supporting the base-isolated building in both of the horizontal direction and the vertical direction by base-isolation manner is installed between the base-isolated building 1 and its foundation 2, and a TMD mechanism 10 is arranged in parallel with the three-dimensional base isolation device. The TMD mechanism is constituted to support an inertia mass damper operating when the base-isolated building causes relative vibration in the vertical direction for the foundation by a support member and synchronize a natural period of the TMD mechanism to be fixed by inertia mass generated by the inertia mass damper and rigidity of the support member with a natural period in the vertical direction of the base-isolated building. Such a TMD mechanism that has a configuration supporting a central part of an oscillating arm 12 having a weight 11 mounted in each of both end parts and arranging the oscillating arm within a vertical face in substantially horizontally to oscillate freely is used in this vertical vibration control system. This system includes a damping device 17 for damping the oscillation generated in the oscillating arm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a three-dimensional seismic isolation system for reducing both horizontal and vertical vibrations of a building, and more particularly to a vertical vibration control system that can effectively attenuate vertical vibrations of a base-isolated building.

As a three-dimensional seismic isolation device for isolating and supporting a building in both the horizontal direction and the vertical direction, those shown in Patent Document 1 and Patent Document 2 have been proposed. The former is a horizontal seismic isolation device made of laminated rubber and a vertical seismic isolation device made of a disc spring laminate, which are stacked in series in the vertical direction, and arranged in series, and the latter are arranged in parallel by arranging them side by side in the horizontal direction. It is a thing.
In any of these three-dimensional seismic isolation devices, the disc spring laminate itself as a vertical seismic isolation device has a vibration damping function, and it is said that a vertical damping effect is naturally obtained. In Patent Document 2, in order to absorb the vibration energy in the vertical direction and ensure the necessary damping, and to easily set the amount of damping, an energy absorbing device such as a hydraulic damper is arranged in parallel with the vertical seismic isolation device. There is also a description that it is provided separately.

JP-A-8-218678 JP 2001-41283 A

  However, in the case of the conventional three-dimensional seismic isolation device shown in Patent Documents 1 and 2, sufficient seismic isolation effect and damping effect for vertical vibrations in particular cannot be obtained, and therefore more effective and appropriate to enable it. In fact, the development of a simple vertical vibration control system is desired.

  In view of the above circumstances, the vertical vibration control system for a base-isolated building according to the present invention is provided between the base-isolated building and its foundation for base-isolating and supporting the base-isolated building in both the horizontal and vertical directions. A three-dimensional seismic isolation device is installed and a TMD mechanism is installed in parallel with the three-dimensional seismic isolation device. When the TMD mechanism generates a relative vibration in the vertical direction with respect to the foundation, The inertial mass damper that operates is supported by a support member, and the natural period of the TMD mechanism determined by the inertial mass by the inertial mass damper and the rigidity of the support member is synchronized with the natural period in the vertical direction of the base-isolated building. It is characterized by that.

As the inertia mass damper, the central portion of a swing arm having weights attached to both ends is supported by the support member, and the swing arm is swingably arranged in a vertical plane substantially horizontally. A structure in which an inertial mass effect due to the vertical vibration of the weight is generated when the moving arm swings following the vertical relative vibration of the base-isolated building can be suitably employed.
In addition, when an inertial mass damper using such a swing arm is used, it is more preferable to provide a damping device for damping the swing generated in the swing arm.

According to the present invention, the horizontal and vertical response accelerations of a base-isolated building during an earthquake can be sufficiently reduced by a three-dimensional seismic isolation device. In particular, a TMD mechanism using an inertial mass damper is parallel to the three-dimensional base isolation device. The vertical acceleration of the base-isolated building can be greatly reduced by installing it on the base station and synchronizing the natural period of the TMD mechanism with the natural period of the base-isolated building.
Further, by using a type in which weights are attached to both ends of the swing arm as the inertial mass damper, a large inertial mass effect can be obtained even with a small mass, and an excellent vibration reduction effect can be obtained.
Furthermore, the vibration reducing effect in the vertical direction can be further enhanced by providing a damping device for damping the swing of the swing arm as the inertia mass damper.

1 is a schematic diagram of a vertical vibration control system for a base-isolated building that is an embodiment of the present invention. It is a figure which shows the vibration reduction effect by a TMD mechanism similarly.

  One embodiment of the present invention is shown in FIGS. FIG. 1 shows a seismic isolation pit provided between the bottom of the base isolation building 1 and the foundation 2, and the base isolation building 1 is exempted in both horizontal and vertical directions. A three-dimensional seismic isolation device 3 is installed to support the earthquake.

The three-dimensional seismic isolation device 3 in this example is obtained by stacking a horizontal seismic isolation device 3A and a vertical seismic isolation device 3B vertically and integrally arranging them in series.
The lower horizontal seismic isolation device 3A is made of an ordinary laminated rubber, and increases (longens) the natural period in the horizontal direction of the base-isolated building 1 due to the characteristic of high vertical rigidity and low horizontal rigidity.
On the other hand, the upper vertical seismic isolation device 3B, like the laminated rubber, is made by alternately laminating steel plates and rubber and integrally bonding them. However, the vertical rigidity is set lower than that of the ordinary laminated rubber, This increases the natural period of the base-isolated building 1 in the vertical direction (vertical direction).
The vertical seismic isolation device 3 </ b> B is interposed between an upper flange 4 of laminated rubber as the horizontal seismic isolation device 3 </ b> A and a holder 5 fixed to the bottom surface of the seismic isolation building 1. When the stopper 6 formed in the portion engages with the upper flange 4 of the horizontal seismic isolation device 3A, the upper flange 4 and the holder 5 are allowed to move in the vertical direction while being allowed to move in the vertical direction. Thus, the vertical seismic isolation device 3B can support only a vertical force without receiving a horizontal shearing force.

  The three-dimensional seismic isolation device 3 functions in the same manner as the conventional three-dimensional seismic isolation devices disclosed in Patent Documents 1 and 2, and provides a seismic isolation effect in both the horizontal and vertical directions. However, since the vertical seismic isolation device 3B has the same configuration as the laminated rubber, the natural period in the vertical direction can be freely adjusted by adjusting the number of laminated steel plates and rubber and the thickness thereof. It can be adjusted widely.

  Therefore, in the vibration damping system of the present embodiment, the horizontal and vertical response accelerations of the base-isolated building 1 at the time of an earthquake can be sufficiently reduced by the above-described three-dimensional seismic isolation device 3, but in this embodiment, in addition to that In order to further reduce the response acceleration in the vertical direction, a TMD mechanism (tuned mass damper mechanism) 10 is installed in parallel with the three-dimensional seismic isolation device 3.

As is well known, the TMD mechanism obtains a vibration reduction effect by utilizing the mass effect of the weight, and an excellent vibration reduction effect can be obtained by synchronizing its natural period with the natural period of the vibration reduction object. However, in this embodiment, when the seismic isolation building 1 supported by the three-dimensional seismic isolation device 3 vibrates in the vertical direction, the TMD mechanism 10 is operated following the seismic isolation building 1 and the natural period is isolated. By synchronizing with the natural period of the building 1 in the vertical direction, the response acceleration in the vertical direction of the base-isolated building 1 can be significantly reduced.
In particular, the TMD mechanism 10 according to the present embodiment uses a so-called balance-type inertia mass damper that swings a swing arm 12 having weights 11 at both ends. Even if it is 11, a large inertial mass effect is obtained and an excellent vibration reduction effect is obtained.

  That is, as shown in FIG. 1, the TMD mechanism 10 of the present embodiment is mainly composed of an inertia mass damper with a swing arm 12 having weights 11 attached to both ends, and a fulcrum at the center of the swing arm 12. 13a is set, and a fulcrum 13b is set at a position slightly deviated therefrom. One fulcrum 13a is pivotally supported at the tip of the upper support member 14 fixed to the bottom surface of the base isolation building 1, and the other fulcrum 13b The tip of the lower support member 15 is connected, and the lower end thereof is supported on a sliding surface 16 provided on the upper surface of the foundation 2 so as to be slidable in the horizontal direction. Further, the weights 11 mounted on both ends of the swing arm 12 are connected to the distal ends of damping devices 17 such as oil dampers, and the base ends of the damping devices 17 are fixed to the bottom surface of the seismic isolation building 1. Yes.

The TMD mechanism 10 configured as described above vibrates in the horizontal direction together with the seismic isolation building 1 when the seismic isolation building 1 vibrates in the horizontal direction (when the horizontal seismic isolation device 3A in the three-dimensional seismic isolation device 3 operates). In this case, the lower end of the lower support member 15 does not slide on the sliding surface 16 in the horizontal direction, and the horizontal displacement of the entire TMD mechanism 10 is not restricted.
When the seismic isolation building 1 vibrates in the vertical direction (when the vertical seismic isolation device 3B in the three-dimensional seismic isolation device 3 is activated), each fulcrum 13a is interposed via the upper support member 14 and the lower support member 15. , 13b are displaced in a direction to be separated from each other in the vertical direction. Therefore, the swing arm 12 swings in the vertical plane as shown in the figure, and both ends thereof vibrate in the vertical direction. At that time, the relative displacement in the vertical direction between the base-isolated building 1 and the foundation 2 is expanded by the “lever principle” and transmitted to the weights 11, and the inertial mass generated by these weights 11 is the actual mass of the weights 11. It is much bigger than that.
Specifically, if the distance from the center of the swing arm 12 to the weight 11 is L and the distance between the fulcrums 13a and 13b is e, the vibration acceleration in the vertical direction of the weight 11 is the seismic isolation building 1 and the foundation 2 Is enlarged by L / e times with respect to the relative acceleration between. Accordingly, when the actual mass of the weight 11 is W, a reaction force obtained by multiplying the inertial mass of (L / e) ² × W by the relative acceleration is transmitted to the seismic isolation building 1, and the TMD having such an inertial mass is transmitted. The acceleration in the vertical direction of the base-isolated building 1 can be effectively reduced by the mechanism 10.

In the TMD mechanism 10 of this type, the inertial mass generated by the weight 11 can be increased by several hundred times the actual mass W. Therefore, even if the weight 11 is sufficiently small and light, a large inertial mass is obtained. The effect can be demonstrated.
Moreover, the natural period of the TMD mechanism 10 is determined by the inertial mass of the swing arm 12 as an inertial mass damper and the vertical rigidity of the upper support member 14 and the lower support member 15. The mass can be freely and widely set by adjusting the mass W of the mass 11, the mounting position of the mass 11 with respect to the swing arm 12 (distance L from the center), and the distance e between the fulcrums 13a and 13b. The natural period of the TMD mechanism 10 can be easily and accurately tuned to the natural period in the vertical direction of the base-isolated building 1.

  Further, by installing an attenuation device 17 such as an oil damper between the weight 11 and the base-isolated building 1 and giving appropriate attenuation to the swing of the swing arm 12 by using the damper 17, the vertical direction It becomes more effective as a vibration control system.

FIG. 2 shows the examination result of the vibration reduction effect in the case of one specific design example.
The specifications to be studied are based on the assumption that the known G4 type laminated rubber is a three-dimensional seismic isolation device, long-term load M = 2000 tons, vertical stiffness K = 10000 tons / cm, and the natural frequency in the vertical direction is 11.1 Hz. The damping constant h = 0.01 in the vertical vibration of the building.
Assuming that the actual mass W of the weight 11 in the TMD mechanism 10 is 1 ton (one side), L = 150 cm, and e = 15 cm, the inertial mass m due to swinging is 0.1 M = 200 ton, and the upper support member 14 and the lower support member 15 The vertical stiffness k was set to 550 ton / cm, and the damping c was set to 2.8 ton / kine.

  In the case of the above specifications, the response magnification is about 50 times in the case of only the three-dimensional seismic isolation device and no TMD mechanism, whereas the response even when there is no attenuation device when the TMD mechanism is installed. The magnification can be reduced to about 35 to 40 times, and when a damping device is provided, the response magnification is drastically reduced to about 5 times (the maximum response value is reduced by 88% compared to the case without the TMD mechanism). be able to.

  Although the embodiment of the present invention has been described above, the gist of the present invention is to reduce the vertical vibration of the seismic isolation building by installing the TMD mechanism using the inertial mass damper in parallel with the three-dimensional seismic isolation device, To that extent, the specific configuration is not limited to the above-described embodiment, and for example, design changes and applications listed below can be made.

  As the TMD mechanism in the present invention, a balance type inertial mass damper using a swing arm as in the above-described embodiment is suitable, but is not limited to this. For example, rotation obtained by rotating a flywheel It is also conceivable to employ other types of inertial mass dampers, such as those utilizing inertial mass.

When using a balance type with a swing arm as the inertial mass damper, the swing arm swings up and down following the vertical motion of the base-isolated building relative to the foundation. In addition, the swing arm and the upper and lower support members that support it may be installed so that unnecessary horizontal force does not act on them. The setting of the position of the fulcrum, the form of support by the support member, and other specific configurations may be appropriate.
For example, in the above embodiment, the swing arm 12 is attached to the base-isolated building 1 via the upper support member 14, and the lower support member 15 can be displaced in the horizontal direction by the sliding surface 16 with respect to the foundation 2. Even if the TMD mechanism is attached to the foundation 2 with the top and bottom of the structure being reversed and the seismic isolation building 1 can be displaced in the horizontal direction, it can function in the same manner.

It is preferable to install a damping device for damping the operation of the TMD mechanism, and in the case of the above embodiment, as a damping device for damping the swing of the swing arm (ie, the weight) as the inertia mass damper. Although it is preferable to add an oil damper or the like, the present invention is not limited to this, and the damping device can be omitted when a desired damping effect can be obtained only by the rotational friction resistance force of the inertia mass damper.
Of course, when installing a damping device, it is needless to say that various damping devices can be employed in addition to the oil damper, and they are not necessarily provided at both ends of the swing arm.

  The three-dimensional seismic isolation device according to the present invention preferably employs a configuration in which a vertical seismic isolation device in the form of a laminated rubber is integrally assembled on top of a laminated rubber as a horizontal seismic isolation device as in the above embodiment. It is possible to use a seismic isolation effect for both horizontal vibrations and vertical vibrations (which can increase the period for both). It is good also as a body, and each structure is also arbitrary.

DESCRIPTION OF SYMBOLS 1 Seismic isolation building 2 Foundation 3 3D seismic isolation device 3A Horizontal seismic isolation device 3B Vertical seismic isolation device 4 Upper flange 5 Holder 6 Stopper 10 TMD mechanism 11 Weight 12 Swing arm (Inertial mass damper)
13a, 13b Support point 14 Upper support member (support member)
15 Lower support member (support member)
16 Sliding surface 17 Damping device

Claims (3)

A three-dimensional seismic isolation device is interposed between the base isolation building and its foundation to support the seismic isolation building in both the horizontal and vertical directions. A TMD mechanism was installed in parallel,
The TMD mechanism includes a support member that supports an inertial mass damper that operates when the base-isolated building generates a relative vibration in a vertical direction with respect to a foundation, and the inertial mass by the inertial mass damper and the support member A vertical vibration control system for a base-isolated building, wherein the natural period of the TMD mechanism determined by rigidity is synchronized with the natural period in the vertical direction of the base-isolated building. A vertical vibration control system for a base-isolated building according to claim 1,
The inertia mass damper is configured such that a center portion of a swing arm having weights attached to both ends thereof is supported by the support member, and the swing arm is swingably arranged in a vertical plane substantially horizontally. A vertical vibration control system for a base-isolated building, wherein an inertial mass effect is generated by the vertical vibration of the weight when the swing arm swings following the vertical relative vibration of the base-isolated building. A vertical vibration control system for a base-isolated building according to claim 2,
The inertial mass damper includes a damping device for damping the swing generated in the swing arm.

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