JPH0784813B2 - Multi-stage seismic isolation support device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a structure of a multi-stage seismic isolation support device installed between a base and a structure to elastically support the structure.

[Prior Art] In a building constructed on a foundation, a machine / equipment installed on a mounting base, etc., it is sometimes required to reduce vibration transmission due to an earthquake or a passing vehicle.

In particular, for structures requiring high safety and precision, such as nuclear facilities, computers or machines for IC wiring, it is desirable to block even minute vibrations over a wide frequency range.

As a mechanism for elastically supporting a structure with respect to a base in order to meet such a demand, a multi-stage seismic isolation support device as shown in FIGS. 1 and 2 is disclosed by the present applicant in Japanese Patent Application No. 59-1346.
Proposed in No. 92.

1 and 2, the multi-stage seismic isolation support device has a plurality of rubber-like elastic bodies 1 vertically (eight in the illustrated example) at a plurality of positions (four in the illustrated example) on a plane. It has a structure in which the upper and lower end surfaces of the rubber-like elastic body 1 at each stage are connected to each other by a stabilizer 2 while being stacked, and are installed between the base 3 and the structure 4 to support the weight of the structure 4. Used to do.

The rubber-like elastic body 1 is a laminated type having a structure in which a rubber-like elastic material and a reinforcing plate such as a steel plate or a hard plastic plate are alternately laminated and integrated from the viewpoint of making vertical displacement small and horizontal displacement sufficiently large. Elastic body is used.

Lower the horizontal natural frequency as much as possible (eg 0.5Hz
With such a multi-stage seismic isolation support device, the horizontal allowable displacement (base 3 and structure 4)
In order to increase the vibration isolation effect by increasing the allowable horizontal relative displacement), it is required to increase the span S in FIG. 2, that is, the connecting length of the stabilizer 2.

FIG. 3 is a graph exemplifying the characteristic of the horizontal restoring force with respect to horizontal displacement with the span S as a parameter. Indicates.

As can be seen from the graph of FIG. 3, the larger the span S, the larger the horizontal allowable displacement (the displacement within the range in which the horizontal restoring force is normally maintained and the buckling phenomenon does not occur) can be increased.

However, in the conventional multi-stage seismic isolation support device, since a flat plate material (steel plate or the like) is used as the stabilizing plate 2, when the span S is increased and the dimension of the stabilizing plate 2 is increased, the stability of the stabilizing plate 2 itself is increased. There is a problem in that the effect of increasing the span due to a significant decrease in bending rigidity, that is, the effect of obtaining a supporting device having a small natural frequency and excellent seismic isolation performance is lost.

That is, in the conventional stabilizer, when the horizontal displacement between the base 3 and the structure 4 becomes large, a bending moment M is generated due to the displacement of the force application point as shown in FIGS. 2 deforms as shown to accelerate the buckling of the rubber-like elastic body 1, and the desired effect cannot be obtained as described above.

〔Purpose〕

The object of the present invention is to solve the problems of the prior art as described above, and to allow a sufficiently large horizontal displacement.
Therefore, it is an object of the present invention to provide a multi-stage type seismic isolation support device capable of sufficiently lowering the natural frequency in the horizontal direction even with a relatively light load and enhancing the vibration isolation effect for the structure.

〔Overview〕

The present invention comprises a laminated body in which a rubber-like elastic material and a reinforcing plate are alternately joined and integrated at a plurality of positions on a plane, and the rubber-like elastic body which mainly displaces in the horizontal direction and exerts a seismic isolation function is vertically arranged. In addition to stacking a plurality of them, and connecting the upper and lower end surfaces of the rubber-like elastic body at a plurality of positions at each stage with a common stabilizing plate, the rubber-like elastic materials are connected in a multi-layered multi-tiered state, The above object is achieved by a multi-stage seismic isolation support device characterized by forming ribs or uneven portions for improving bending rigidity on each stabilizer.

〔Example〕

The present invention will be specifically described below with reference to FIGS.

FIG. 5 shows the essential parts of the multi-stage seismic isolation support system according to the first embodiment.

In this embodiment, each stabilizer 2A has a structure in which two ribs 6A extending vertically and horizontally are welded to one surface (bottom surface in the illustrated example) of a flat plate 5A, and the second moment of area is greater than that of the flat plate 5A. The bending rigidity is greatly improved by significantly improving the bending strength.

The entire structure of this embodiment is substantially the same as the structure of FIG. 1 except that the above-described stabilizer 2A is used instead of the plate-shaped stabilizer 2.

Therefore, in the multi-stage seismic isolation support device of this embodiment, a plurality of rubber-like elastic bodies 1 are stacked vertically (e.g., 8) at a plurality of positions (for example, 4 positions) on a plane and the rubber-like elastic bodies 1 at each stage are stacked. The upper and lower end surfaces are connected by each stabilizer 2A, and the weight of the structure 4 is supported between each rubber-like elastic body 1, that is, between the upper and lower surfaces of the seismic isolation support device.

According to the embodiment shown in FIG. 5, the ribs 6A are welded to the respective stabilizers 2A to improve the bending rigidity. Therefore, the interval between the rubber-like elastic bodies 1, that is, the span S is set to be large and the allowable horizontal displacement ( The allowable limit of horizontal displacement between the base 3 and the structure 4) can be set sufficiently large, and the seismic isolation effect can be enhanced.

In addition, the stabilizer 2A can be made thin and lightweight.

FIG. 6 shows the essential parts of a multistage seismic isolation support system according to the second embodiment.

In this embodiment, each stabilizer 2B has a structure in which a rib 6B extending in a diagonal direction is welded to one surface (the upper surface in the illustrated example) of a flat plate 5B, and each rubber-like elastic body 1 is formed on the stabilizer 2B. It is connected to each side part.

Also in this embodiment, as in the case of the first embodiment, the stabilizing plate
The allowable horizontal displacement can be increased by increasing the bending rigidity of 2B, thus improving seismic isolation performance and stabilizing board.
The weight of 2B can be reduced.

FIG. 7 shows the essential parts of a multi-stage seismic isolation support system according to the third embodiment.

In this embodiment, the bending rigidity of the stabilizers 2C is improved by forming the uneven portion 6C of a predetermined pattern on the surface of each stabilizer 2C.

Further, FIG. 8 shows a main part of the multi-stage seismic isolation support system according to the fourth embodiment. In this embodiment, the uneven plate 6D having a pattern different from that of the case of FIG. The bending rigidity of is improved.

Also according to the embodiments shown in FIGS. 7 and 8, the bending rigidity of the stabilizers 2C and 2D can be sufficiently increased by selecting the shapes and arrangements of the concave-convex shaped portions 6C and 6D. Similar to the case where the ribs 6A and 6B are welded, the allowable displacement in the horizontal direction is increased and the seismic isolation performance can be improved, and at the same time, the weight of the stabilizers 2C and 2D can be reduced.

FIG. 9 shows the essential parts of a multi-stage seismic isolation support system according to the fifth embodiment.

In this embodiment, the periphery (4 sides in the illustrated example) of each stabilizer 2E is bent (in the illustrated example, bent upward).
An integral rib 6E is formed, which improves the bending rigidity of the stabilizer 2E.

According to this embodiment, as in the case of each of the above-described embodiments, the allowable horizontal displacement can be increased by increasing the rigidity of the stabilizing board 2E, and thus the seismic isolation performance can be improved and the stabilizing board 2E can be improved. The weight can be reduced.

In each of the above examples, the ribs 6A are attached to the square stabilizers 2A to 2E,
6B, 6E or uneven portions 6C, 6D are formed to improve the bending rigidity, but the shape of the stabilizers 2A to 2E is a suitable shape other than a quadrangle, that is, a desired shape corresponding to the arrangement of the rubber-like elastic body 1. The pattern shape can be any shape, and the ribs and the uneven portions can be formed in an appropriate combination if necessary.

FIG. 10 is a graph exemplifying the difference in horizontal allowable displacement between the case of implementing the present invention and the conventional multi-stage seismic isolation support device.

In the graph of FIG. 10, the horizontal axis represents the horizontal displacement (horizontal displacement between the base 3 and the structure 4), the vertical axis represents the elastic restoring force of the seismic isolation support device, and the chain line X represents the conventional structure. As for the restoring force characteristic, the solid line Y shows the restoring force characteristic of the embodied structure of the present invention.

[Effect] As is apparent from the above description, according to the multi-stage seismic isolation support device of the present invention, it is composed of a laminated body in which the rubber-like elastic material and the reinforcing plate are alternately joined and integrated at a plurality of positions on the plane. , By stacking a plurality of rubber-like elastic bodies vertically displacing mainly in the horizontal direction and exhibiting a seismic isolation function, and connecting the upper and lower end surfaces of the rubber-like elastic bodies at a plurality of positions at each stage with a common stabilizer, Since rubber-like elastic materials are connected in a multi-layered manner in a multi-layered stack and are formed with ribs or uneven portions for improving bending rigidity on each of the stabilizers, the rubber plate of each layer is By connecting elastic bodies to increase horizontal allowable displacement, seismic isolation performance can be improved.
By improving the bending rigidity of the stabilizer, a multistage seismic isolation support device is provided which can improve the seismic isolation performance by further increasing the allowable horizontal displacement without increasing the weight.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a multistage seismic isolation support device, and FIG.
The figure is a partial cross-sectional plan view taken along the line II-II in FIG.
The figure is a graph illustrating the relationship between the span of the stabilizer and the allowable horizontal displacement, FIGS. 4A and 4B are explanatory views illustrating the bending deformation and bending moment distribution of the stabilizer, and FIGS. 5 to 9.
Each of the drawings is a perspective view showing the main part of a multi-stage seismic isolation support device according to each embodiment of the present invention, and FIG. 10 illustrates an increase in the allowable horizontal displacement when the present invention is carried out in comparison with a conventional structure. It is a graph. 1 ... rubber-like elastic body, 2A-2E ... stabilizer, 3 ... base,
4 ... Structure, 6A to 6E ... Ribs or uneven parts.

Claims (1)

[Claims] Claim: What is claimed is: 1. A rubber-like elastic body having a seismic isolation function, which comprises a laminated body in which a rubber-like elastic material and a reinforcing plate are alternately joined and integrated at a plurality of positions on a plane and is mainly displaced in the horizontal direction. By stacking a plurality of top and bottom and connecting the upper and lower end surfaces of the rubber-like elastic body at multiple positions in each stage with a common stabilizing plate, the rubber-like elastic materials are connected in a multi-tiered multi-tiered stacked state, A multi-stage seismic isolation support device, characterized in that ribs or concavo-convex portions for improving bending rigidity are formed on each of the stabilizers.