JPH0914345A - Base isolation device for light load - Google Patents

Abstract

PURPOSE: To naturally return a construction and a base body of a ground side to their original positions after vibration vanishes by fixing the upper end of a load receiving body to a construction side and by making the lower end thereof a sliding surface relative to the base body of the ground side and fixing the upper end of an elastic body to the construction side and the lower end thereof to the base body of the ground side. CONSTITUTION: A load receiving body 1 comprises an attaching plate 11 which is on the main body 10 and attaches the body 1 to a construction A and a sliding plate 3 (sliding surface 30) fixed to the underside of the main body 10. An elastic body 2 is fixed to the construction A and a base body B of a ground side via attaching plates 21, 22 with a gap around the load receiving body 1. When a horizontal vibration acts on the base body B of the ground side, the construction A and the base body B of the ground side are relatively moved because there is the sliding plate 3, whereby the energy of horizontal vibration acting on the base body B of the ground side is damped and transmitted to the construction A. After the vibration vanishes, the construction A and the base body B of the ground side are naturally returned to the original positions by the elastic returning force of the elastic body 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light load seismic isolation device.

[0002]

2. Description of the Related Art As a seismic isolation device, for example, as shown in FIG. 7, a rubber plate 90 and a metal plate 91 are alternately laminated and fixed (hereinafter, this part is referred to as an isolator) and attached to the upper and lower parts thereof. There is a structure in which the plates 93 and 94 are fixed to each other. In this device, the upper mounting plate 93 is attached to the structure A
Then, the lower mounting plate 94 is installed on the ground-side base body B so as to be mounted respectively.

Therefore, when horizontal vibration occurs on the ground side, the isolator portion is sheared and deformed, whereby the vibration energy transmitted from the ground side base body B to the structure A side is absorbed.

However, when the seismic isolation device having the above-mentioned structure is adopted for a lightly loaded structure, there is a problem that the vibration energy is not sufficiently absorbed due to the large shear spring constant of the isolator portion. If the pressure receiving area is reduced in order to reduce the shear spring constant of the portion, there is a problem that a buckling phenomenon occurs.

Therefore, in order to solve the above problems, a seismic isolation device as shown in FIG. 8 has been devised. This device, as shown in FIG. 8, has a mounting plate 93 fixed to the upper part of the isolator.
Only the only one is attached to the building A side, and the lower part of the isolator is installed so as to be slidable with respect to the ground side base body B. That is, in this device, the sliding plate 95 having a relatively small friction coefficient is fixed to the lower portion of the isolator without attaching the lower portion of the isolator to the ground side base body B.

Therefore, even if the shear spring constant of the isolator portion is relatively large, due to the synergistic effect of the shear deformation of the isolator and the slip between the isolator and the ground side foundation body B, the ground side foundation body B is The vibration energy transmitted from the structure to the structure A side is relatively greatly relaxed. Therefore, since the shear spring constant of the isolator portion can be set relatively large, that is, the pressure receiving area of the isolator portion can be set large, the buckling phenomenon hardly occurs.

However, in this apparatus, when the relative positional relationship between the structure A and the ground-side foundation B is deviated due to the vibration on the ground-side foundation B side, the original positional relationship is not restored naturally. There is.

[0008]

Therefore, in the present invention, the vibration energy can be sufficiently relaxed, the buckling phenomenon does not occur, and the structure and the ground side foundation body naturally return to the original positional relationship after the vibration disappears. An object of the present invention is to provide a seismic isolation device for light loads.

[0009]

A seismic isolation device for a light load according to the present invention is provided around a load receiving body 1 having a pressure receiving area such that the structure A does not buckle under the load of the structure A and the load receiving body 1. The load receiving body 1 has an upper end portion fixed to the structure A side and a lower end portion serving as a sliding surface 30 capable of sliding with respect to the ground side base body B, while the elastic body 2 is provided. The seismic isolation device for light loads, characterized in that the upper part of the above is fixed to the structure A side and the lower part thereof is fixed to the ground side foundation body B side, respectively.

Further, the seismic isolation device for a light load of the present invention has a load receiving body 1 having a pressure receiving area that is not buckled by the load of the structure A, and an elastic body provided around the load receiving body 1. 2, the upper end of the load receiver 1 is a sliding surface 30 that can slide on the structure A, and the lower end is fixed to the ground side base body B side, while the upper part of the elastic body 2 is Is fixed to the structure A side, and the lower portion is fixed to the ground side foundation body B side.

[0011]

The present invention operates as follows. When horizontal vibration acts on the ground-side foundation B, the structure A and the ground-side foundation B move horizontally relative to each other due to the presence of the sliding plate 3 provided at the lower end (or upper end) of the load receiver 1. Therefore, the energy of the horizontal vibration acting on the ground side base body B is sufficiently relaxed and transmitted to the structure A side. In this structure, the ability to relax the energy of horizontal vibration has nothing to do with the pressure receiving area of the load receiving body 1, and therefore the pressure receiving area of the load receiving body 1 is set to such a degree that it does not buckle under the load of the structure A. can do. After the vibration disappears, the elastic return force of the elastic body 2 provided around the load receiver 1 causes the structure A and the ground side base body B to naturally return to the original positional relationship.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described with reference to the drawings shown as embodiments.

The seismic isolation device for light loads of this embodiment is installed between a structure A and a ground side foundation B as shown in FIG. 1, and basically, as shown in FIG. A load receiver 1 having a pressure receiving area that does not buckle under the load of the structure A;
The elastic body 2 is provided around the load receiver 1.

The load receiver 1 is, as shown in FIG. 1 and FIG.
A main body 10 formed of a cylindrical steel material, and a mounting plate 11 on the upper part of the main body 10 for mounting the structure A on the main body 10.
And a sliding plate 3 (a contact surface with the ground side base body B is a sliding surface 30) fixed to the lower end surface of the main body 10. The load receiver 1 is bolted to the structure A via the mounting plate 10.

The elastic body 2 is, as shown in FIG. 1 or 2,
The main body 20 made of a tubular rubber material, and the main body 2
It consists of the mounting plates 21 and 22 fixed to the upper and lower parts of 0,
The load receiver 1 is arranged so as to surround the entire circumference of the load receiver 1 with a gap G. As shown in FIG. 1, the elastic body 2 is fixed to the structure A and the ground side base body B via the mounting plates 21 and 22. As the rubber material forming the elastic body 2, natural rubber, isoprene rubber, styrene rubber, urethane rubber, silicon rubber, or the like can be used.
Furthermore, so-called high damping rubber (a rubber material having a spring element of rubber molecules, a friction element where the molecules rub against each other, and a viscous damping element, and a high absorption rate of vibration energy due to the synergistic effect of these elements) Can be used.

The function of the light load seismic isolation device will now be described. When horizontal vibration acts on the ground-side foundation body B, the presence of the sliding plate 3 causes the structure A to move as shown in FIG.
And the ground-side foundation B move horizontally relative to each other (horizontal relative movement in which the structure A tries to stop at that position due to inertia), and the energy of the horizontal vibration acting on the ground-side foundation B is relaxed. Is transmitted to the structure A side. Then, after the vibration disappears, the structure A and the ground side foundation body B are restored from the state of FIG. 3 to the state of FIG. 1 by the elastic restoring force of the elastic body 2 provided around the load receiver 1. Naturally returns to the positional relationship.

The seismic isolation device of the above embodiment may be replaced with the following structure. (Structure Aspect 1) The main body 10 is formed by alternately laminating and fixing steel plates 12 and rubber plates 13 as shown in FIGS. 4 and 5, while the main body 20 is formed by a steel plate 23 as shown in FIG. And the rubber plate 24 are alternately laminated and fixed.
In this case, sliding of the main body 10 with respect to the ground-side foundation B,
Due to the shear deformation of the main body 10, the energy of the horizontal vibration transmitted from the ground side foundation body B to the structure A can be greatly relaxed. (Structure Mode 2) The elastic body 2 may be formed of a thin columnar rubber body 25, and the rubber body 25 may be arranged in a mode as shown in FIG. (Structure Mode 3) A mode in which the load receiver 1 is installed upside down from the above-described first and second embodiments, that is, the sliding plate 3 that is slidable with respect to the structure A is provided on the upper end surface of the main body 10, and only the lower end part is provided. Even if is fixed to the ground-side base body B, the same effects as those described above can be obtained.

[0018]

From the contents described in the section of action, vibration energy can be sufficiently relaxed, buckling phenomenon does not occur,
It was possible to provide a seismic isolation device for light loads in which the structure and the foundation on the ground side naturally return to their original positional relationship after the vibration disappeared.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a seismic isolation device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the seismic isolation device according to the embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing a state of the seismic isolation device when horizontal vibration acts on the ground side foundation body side.

FIG. 4 is a vertical cross-sectional view showing the seismic isolation device according to the configuration mode 1 of the embodiment of the present invention.

FIG. 5 is a partial cross-sectional perspective view showing the seismic isolation device according to configuration mode 1 of the embodiment of the present invention.

FIG. 6 is a plan layout view of the seismic isolation device according to the configuration mode 2 of the embodiment of the present invention.

FIG. 7 is a vertical sectional view of a conventional seismic isolation device.

FIG. 8 is a longitudinal sectional view of another prior art seismic isolation device.

[Explanation of symbols]

 A structure B ground side foundation 1 load receiver 2 elastic body 3 sliding plate 30 sliding surface

Claims (4)

[Claims] 1. A load receiving body (1) having a pressure receiving area that does not buckle under a load of a structure (A), and an elastic body (2) provided around the load receiving body (1). And the upper end of the load receiver (1) is fixed to the structure (A) side and the lower end is a sliding surface (30) that can slide with respect to the ground side foundation (B), while the elastic body is The seismic isolation device for light loads, wherein the upper part in (2) is fixed to the structure (A) side and the lower part is fixed to the ground side foundation body (B) side, respectively. 2. A load receiving body (1) having a pressure receiving area that does not buckle under the load of the structure (A), and an elastic body (2) provided around the load receiving body (1). And the upper end of the load receiver (1) is a sliding surface (30) that can slide with respect to the structure (A), and the lower end is fixed to the ground side foundation (B) side, while A seismic isolation device for light load, wherein an upper part of the elastic body (2) is fixed to a structure (A) side and a lower part thereof is fixed to a ground side foundation (B) side, respectively. 3. The load receiver (1) comprises a main body (10) made of a highly rigid metal, and a sliding plate (3) having a sliding surface (30) fixed to the main body (10). The seismic isolation device for light loads according to claim 1 or 2, characterized by being provided. 4. A main body (10) in which a load receiver (1) is formed by alternately laminating and fixing a rubber plate (12) and a metal plate (13).
And a sliding plate (3) having a sliding surface (30) fixed to the main body (10), the seismic isolation device for light loads according to claim 1 or 2.