JPH07324517A - Vibration control structure - Google Patents

Abstract

PURPOSE:To provide a vibration control structure which has the simple structure and possesses the high vibration control effect, in comparison with that in the conventional, even for the vibration having the high mode. CONSTITUTION:A substructure 2 having five stages 2A-2E is built in a megastructure 1. The floor members 2b-2e of the floors 2B-2E over the second floor 2B of the substructure 2 are supported in a relative vibration enabled form in the horizontal direction, on the megastructure 1 through a high damping multistage laminated rubber 6. Accordingly, the megastructure 1 and the substructure 2 are joined together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping structure having a high vibration damping effect against vibrations caused by earthquakes, winds and the like.

[0002]

2. Description of the Related Art A vibration control structure is a structure provided with means for damping the vibration of the structure caused by an earthquake, wind, etc., and various proposals have been made in recent years. One of the proposals is a damping structure that applies seismic isolation structures to the substructure of high-rise structures. High-rise structures, especially in the case of ultra-high rise, have a span, floor height,
It often takes the form of a megastructure with a remarkably large cross-sectional dimension. In addition, since the wind load is often dominant, the design will be within the elastic range of the megastructure. Such designs can only be expected to have very low internal damping in the building, and thus exhibit an over-reaction to earthquakes and wind. Therefore, many damping devices have been proposed for the purpose of adding damping to the building, but most of them utilize the interlayer displacement of the building.
However, in a high-rise structure, bending deformation due to axial expansion and contraction of columns is dominant, and thus interlayer deformation is unlikely to occur, and it is difficult to directly apply such a damping device.

As one method of solving this problem, in recent years, FIG.
As shown in, the substructure 12 is built in the megastructure 11, and the substructure 12 is suspended from the upper part of the megastructure 11 via the suspension member 13, and the floor 15 of each floor of the substructure 12 and the megastructure 11 are Dampers 16 are installed between the substructures 12 on the floor 15 of each floor.
A vibration damping structure having a structure that damps horizontal relative vibration between the and the mega structure 11 has been proposed.

[0004]

In such a vibration control structure, since the substructure is suspended from the megastructure, the natural frequency of the substructure is determined by the suspension length. Also, due to the structural constraint that the substructure is suspended from the megastructure, it is practically difficult to extend the suspension length to reduce the natural frequency of the substructure and increase the natural period. . Further, since the natural frequency of the substructure is almost determined by the suspension length, it is difficult to adjust the natural frequency of the substructure by a portion other than the suspension length such as a damper. However, recently, it has been found that the longer the natural period of the substructure is, the higher the damping effect can be exhibited. Therefore, the conventional damping structure as described above has a problem that such a high damping effect cannot be exerted.

Further, in such a vibration control structure, since the substructure is suspended from the upper portion of the megastructure via the suspension member, it is not possible to excite high mode vibrations in the substructure. Therefore,
There is a problem that it is difficult to quickly damp such high mode vibrations when they occur in the megastructure.

Further, since such a vibration damping structure is usually very large in scale, the substructure is also very large. However, in the case of the suspension structure type, the heavy load is concentrated on the suspension member. Therefore,
There is a problem that the suspension mechanism including the suspension member must be very large-scaled.

In view of the above circumstances, the present invention provides a vibration damping structure which can be simplified in structure and which has a high vibration damping effect including the vibration of a high mode more than ever before. Has an aim.

[0008]

According to a first aspect of the present invention, there is provided a vibration control structure, wherein a sub-frame is provided inside a main frame so as to be capable of relative vibration in a horizontal direction via elastic damping means. Is configured to have a plurality of floors in the vertical direction, and floor members of at least two floors of the floor members of the plurality of floors can be relatively vibrated in the horizontal direction relative to the main frame via the elastic damping means. Characterized by being supported. The damping structure according to claim 2 is the damping structure according to claim 1, wherein the elastic damping means is a laminated rubber, and the sub-frame is mounted on a slab of the main frame via a sliding bearing. It is characterized in that it is supported so as to be capable of relative vibration in the horizontal direction.

[0009]

According to the vibration control structure of the present invention, at least two floor members of the floor members of the plurality of floors of the sub-frame are horizontally opposed to the main frame via elastic damping means. Since it is supported so that it can vibrate, the load burden is dispersed compared to the conventional suspension type. Therefore, the support structure between the main frame and the sub frame becomes compact. Further, by adjusting the rigidity of the elastic damping means, unlike the conventional suspension type, the natural frequency of the subframe can be easily reduced. Further, since the weights of at least two floors of the sub-frame are supported by the main frame via the elastic damping means, the sub-frame can vibrate in different phases for each floor. The vibration damping structure according to claim 2 operates similarly to the vibration damping structure according to claim 1.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. On the ground, as shown in FIG.
0 is provided, and the vibration damping structure 100 includes a megastructure 1 provided on the ground and a substructure 2 supported inside the megastructure 1 via a laminated rubber 6 so as to be capable of relative vibration in the horizontal direction. Is equipped with.

The substructure 2 has five floors 2A, 2B, 2C, 2D, and 2E from the bottom to the top. In this embodiment, the substructure 2 is divided into five floors 2A, 2B, 2C, and 2 for simplification of description.
Although it has been described as having D and 2E, it is not always necessary to have five floors, and it goes without saying that the number of floors may be any number as long as it has a plurality of floors or more.

The substructure 2 is provided in a substructure installation space S1 formed inside the megastructure 1, and is located on the first floor 2 of the substructure 2.
The floor member 2a of A is supported on the slab 1a of the megastructure 1 via a slide bearing 5 so as to be capable of relative vibration in the horizontal direction.

The floor members 2b of the second floor 2B of the substructure 2 respectively project from the side surfaces of the substructure 2 in the horizontal direction, and the end portions of the floor members 2b are raised to the floor support portion 1b formed on the megastructure 1. It is supported by a damping multi-stage laminated rubber 6 so as to be relatively vibrable in the horizontal direction. The floor members 2c, 2d, and 2e of the floors 2C, 2D, and 2E of the third floor and above, like the floor member 2b of the second floor 2B, are the floor support portions 1c and 1d provided on the megastructure 1 at the height position of each floor. 1e, high damping multi-stage laminated rubber 6
It is supported via the through so that relative vibration is possible in the horizontal direction.

As shown in FIG. 2, the high-damping multistage laminated rubber 6 is obtained by alternately laminating a rigid plate 6a having a diameter of about 20 cm and a plurality of laminated high-damping laminated rubbers 6b. The laminated rubber shown in FIG. In FIG. 6, four high-damping laminated rubbers 6b are laminated between each of the five rigid plates 6a. In addition, between each rigid plate 6a, four laminated high damping rubber layers 6 are provided.
A plurality of b are provided, and this high-damping multistage laminated rubber 6
Has a feature that it can support the load in the vertical direction and has extremely low rigidity in the horizontal direction.
The floor members 2a to 2e can be supported in the horizontal direction so as to be relatively vibrable. Further, the high damping laminated rubber 6b has a high damping property of deforming in the horizontal direction and absorbing the applied energy. Therefore, the high damping multi-stage laminated rubber 6
Can be said to be a very compact device with load bearing and damping functions.

Since the vibration control structure 100 and the like have the above-described structure, the megastructure 1 is protected from wind and earthquakes.
When it vibrates in the horizontal direction, the floor support portions 1b, 1c, 1d, 1e of the megastructure 1 pass through the high-damping multistage laminated rubber 6 and the floors 2B to 2E of the substructure 2 respectively.
The vibration is transmitted to the floor members 2b to 2e, and the substructure 2 vibrates in the horizontal direction centering on the floor members 2b to 2e. Then, the vibration of the megastructure 1 is absorbed by the vibration of the substructure 2, so that the vibration of the megastructure 1 can be damped.

Further, the vibration of the substructure 2 is caused by the high damping multistage laminated rubber 6 provided between the floor members 2b to 2e of the substructure 2 and the floor supporting portions 1b to 1e of the megastructure 1. Since it can absorb energy, it can damp the vibration of each floor. Therefore, the structure for damping 1 by wind and earthquake
The vibration generated at 00 can be quickly damped.

Further, in the above embodiment, the substructure 2 is slidably mounted on the floor members 2a to 2e of the respective floors 2A to 2E through the slide bearings 5 or the high damping multistage laminated rubber 6 and a plurality of slabs 1a of the megastructure 1 and a plurality of them. Since it is provided so as to be supported by the floor supporting portions 1b to 1e, it is possible to disperse the load load on the substructure 2 as compared with the case of the conventional hanging type. Therefore, the mechanism for supporting the load of the substructure 2 can be constituted by the compact high-damping multistage laminated rubber 6 and the sliding bearing 5. Therefore, the support structure between the megastructure 1 and the substructure 2 can be made compact, so that the structure of the vibration damping structure 100 can be simplified. Specifically, the high-damping multistage laminated rubber 6 used in this example is a high-damping multistage laminated rubber having an allowable surface pressure of about 100 kgf / cm 2, and its diameter is 20 cm. Therefore,
The permissible supporting load per high damping multi-stage laminated rubber 6 is
It will be about 31 tonf. In this embodiment, the floor weight of the substructure 2 is 25 m × 25 m × 0.7 t / cm 2 = 43.
It is assumed to be 7.5t, and about 14 high-damping multistage laminated rubbers 6 are required to support this weight. Therefore, in the present embodiment, four high-damping multistage laminated rubbers 6 are arranged in parallel at the four corners of each floor member 2b to 2e. Therefore, each floor member 2b to 2e of the substructure 2 has a total of 1
It is supported by six high damping multi-stage laminated rubbers 6. Therefore, it can be said that the support structure is more compact than the conventional suspension type.

Further, in the above embodiment, when the substructure 2 is supported by the megastructure 1, each floor 2B of the second floor 2B and above of the substructure 2
Floor members 2b to 2e of 2E are attached to the floor supporting portions 1b to 1e of the megastructure 1 via the high-damping multistage laminated rubber 6, respectively.
Since the high damping multi-stage laminated rubber 6 having a different number of stages, different diameters, etc. is used or the number thereof is increased or decreased, the rigidity of the high damping multi-stage laminated rubber 6 can be easily increased or decreased. I can. Therefore, unlike the conventional suspension type, the natural frequency of the substructure 2 can be easily adjusted, and the high-damping multistage laminated rubber 6 is
Since it has a very small horizontal rigidity, the natural frequency of the substructure 2 can be set smaller than that of the conventional one.

This is shown by the following simple arithmetic expression. First, the rigidity κ (laminated rubber shear rigidity) of the high-damping multi-stage laminated rubber 6 is expressed by the equation 1 where G is the shear elastic modulus of the rubber, A is the laminated rubber pressure receiving area, and n · tR is the rubber layer thickness. You can

[Equation 1] The rigidity of the substructure 2 can be the rigidity κ of the highly damped multistage laminated rubber 6. Therefore, the natural period T of the substructure 2 can be expressed as in Equation 2 when its mass is m.

[Equation 2] Here, assuming that the surface pressure applied to the high-damping multi-stage laminated rubber 6 is σ, the surface pressure σ can be expressed as in Equation 3.
Note that g is the acceleration of gravity.

[Equation 3] Then, from Equations 2 and 3, the natural period T of the substructure 2 can be expressed as Equation 4.

[Equation 4]

Therefore, it can be seen that the natural period T of the substructure 2 is proportional to the square of the surface pressure σ and inversely proportional to the square of the rigidity κ. Further, the rigidity κ is inversely proportional to the rubber layer thickness n · tR as shown in Equation 1. Therefore, the natural period T of the substructure 2 is proportional to the square of the surface pressure σ, and
It can be said that it is proportional to the square of the rubber layer thickness n · tR. Therefore,
By using the high-damping multi-stage laminated rubber 6 of the above-described embodiment with high surface pressure, or increasing the number of stages of the high-damping laminated rubber 6b to reduce the rigidity κ, the natural period T of the substructure 2 can be easily obtained. Can be lengthened. Here, since the natural period T is represented by the reciprocal of the natural frequency as is well known, in other words, the natural frequency of the substructure 2 can be set smaller than that of the conventional one. I can say.

Therefore, the vibration of the megastructure 1, that is, the vibration of the vibration damping structure 100 can be made to have a natural frequency more effectively damped than that of the conventional vibration damping structure.
Therefore, it is possible to exert a higher vibration damping effect than ever before.

Further, in the vibration damping structure 100 of this embodiment,
The end portions of the floor members 2b to 2e of the second floor 2B and higher floors 2B to 2E of the substructure 2 are attached to the floor support portions 1b to 1e formed at the height positions of the respective floors of the megastructure 1, and the high damping multistage laminated rubber 6 is provided. Is supported so as to be capable of relative vibration in the horizontal direction. Therefore, the substructure 2 can vibrate with different phases for each floor 2B to 2E. Therefore, the vibration of the mega structure 1 is 2B on each floor.
Since it can be damped every ~ 2E, the vibration of the megastructure 1 is a high mode vibration (that is, each floor 2B ~ 2
Even if the vibration has a different phase for each E, the vibration can be quickly attenuated. Therefore, the vibration of the vibration damping structure 100 can be quickly attenuated.

[0023]

According to the damping structure of the first aspect of the present invention, the load burden of the sub-frame can be dispersed as compared with the conventional suspension type. Therefore, the support structure between the main frame and the sub frame can be made compact, and the structure of the vibration damping structure can be simplified. Also, by adjusting the rigidity of the elastic damping means, unlike the conventional suspension type, the natural frequency of the sub-frame can be easily reduced, so the natural frequency of the sub-frame of the conventional damping structure can be reduced. It is possible to set the natural frequency to more effectively dampen the vibration of the main frame. Therefore, it is possible to exert a higher vibration damping effect than ever before. Moreover, since the sub-frame can vibrate in different phases for each floor, the vibration of the main frame can be damped for each floor. Therefore, even if the vibration of the main frame has a high mode vibration, that is, even if each phase has a different phase, the vibration can be quickly attenuated. The damping structure according to claim 2 has the same effect as the damping structure according to claim 1.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a vibration damping structure of the present invention.

FIG. 2 is a diagram showing a highly damped multi-stage laminated rubber of the vibration damping structure of FIG.

FIG. 3 is a diagram showing a conventional suspension type damping structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Megastructure (main frame) 2 ... Substructure (subframe) 2A-2E ... 1st floor-5th floor (plural floors) 2b-2e ... Floor member 5 ... Sliding bearing 6 ... High damping multi-stage laminated rubber (elastic damping means) , Laminated rubber) 100 ... Damping structure

Claims (2)

[Claims] 1. A sub-frame is provided inside a main frame so as to be capable of relative vibration in the horizontal direction via elastic damping means, and the sub-frame is constructed to have a plurality of floors in the vertical direction. The floor member of at least two floors among the floor members of the floors is respectively supported by the main frame via the elastic damping means so as to be relatively vibrable in the horizontal direction. Swing structure. 2. The damping structure according to claim 1, wherein the elastic damping means is a laminated rubber, and the sub-frame is horizontally vibrated on a slab of the main frame via a sliding bearing. Vibration control structure characterized by being freely supported.