JPH0415352B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a seismic isolation support device for structures that supports the load of structures such as buildings and absorbs vibrations during earthquakes. This invention relates to a seismic isolation support device that utilizes viscous shear resistance.

[Prior art] As a seismic isolation support device for this type of structure,
No. 59-179970 (hereinafter referred to as "prior art").

FIG. 3 shows the structure of the prior art seismic isolation device.
This device has a low-friction material c on the lower surface between a mounting plate a to which the base G of the installation object is attached and a fixed plate b fixed to the base part B, and a gap exists between the plate and the fixed plate B to resist viscous resistance. A support e having a surface d is provided, the outside of the support is surrounded by a hollow cylindrical rubber f, and a viscous body g is enclosed inside the support so as to fill the gap. With this configuration, when the structure is subjected to forced vibration due to an earthquake or other external force, the support e slides on the fixed platen b via the low-friction material c, and as a result of this sliding displacement, the lower surface of the support e and the fixed platen b The upper surface of the supporting member e receives a viscous shearing resistance force due to the viscous body g interposed between the two surfaces, thereby preventing displacement of the support e and, in turn, the structure.

Since this device relies on viscous shear resistance, it acts sensitively against earthquake vibrations, quickly attenuates seismic energy, and can move horizontally in all directions.

However, during an earthquake, a structure may receive a negative reaction force or an overturning moment, and an upward lifting force may act on this support device. If this upper lift is less than the vertical load of the structure, there is no particular problem, but
When the upper lifting force exceeds the vertical load acting on the support device, the gap between the lower surface of the support of the support device and the upper surface of the stationary plate changes (increases the gap), resulting in a problem of deterioration of the damping function. especially,
This problem becomes a major technical challenge when applying this type of device to a lightweight building (for example, a residential building with about 1 to 3 layers).

[Technical Problem of the Present Invention] The present invention has been made to solve the problems of the above-mentioned prior art. The purpose of the present invention is to provide a seismic isolation support device that effectively utilizes the vibration absorption effect of the superstructure, provides a means for restraining the upper lift force acting on the superstructure, and does not change the damping function even when the upper lift force is applied. This is a technical issue.

[Configuration of the present invention] In order to achieve the above object, the seismic isolation support device for structures of the present invention adopts the following configuration (technical means). That is, it consists of a support that is vertically installed from the lower surface of the upper structure and has a resistance plate horizontally attached to its lower end, and a lower plate and an upper plate, and the resistance plate is moved horizontally through a movement range. The resistance plate is composed of a casing fixed to a foundation that can be freely accommodated, and a viscous material filled in the casing. Movement in the vertical direction is restrained by the plate, and by the lower surface of the resistor plate, the upper surface of the lower plate, the upper surface of the resistor plate, the lower surface of the upper plate, and the viscous body interposed between these opposing surfaces. It is characterized by forming a viscous shear resistance generating part.

In the above configuration, the bearing material provided protrudingly on the upper and lower surfaces of the resistance plate plays a supporting role of transmitting the load of the upper structure to the lower structure, and also supports the resistance plate sandwiched between the upper and lower plates of the casing. It serves a multi-functional role, allowing smooth sliding and maintaining a minute gap between the upper and lower plates and the resistance plate.

In addition to ordinary viscous materials such as silicone oil, examples of viscous materials include viscous materials with high viscosity, such as polymeric viscous materials such as polyisobretin, polypropylene, and polybutene, in order to particularly improve damping characteristics.
Alternatively, asphalt may be used.

[Operation] Under normal conditions, the load of the upper structure is transmitted from the support to the lower plate of the casing via the lower bearing material on the lower surface of the resistance plate, and the structure is stably supported.

When a sudden external force such as an earthquake acts on a structure, the structure undergoes forced vibration, and this vibrational displacement causes movement of the resistance plate via the support, causing relative movement between it and the casing fixed to the foundation. This relative motion ultimately results in a relative displacement between two surfaces (the upper surface of the resistor plate and the lower surface of the upper plate, and the lower surface of the resistor plate and the upper surface of the lower plate) that face each other with a microgap between them via the bearing material. Since a viscous body exists between these two surfaces, a viscous shearing resistance force is generated on these plate surfaces in a direction opposite to the direction of displacement. As a result, the structure receives a braking force due to this viscous shear resistance force, and its vibrations are quickly damped.

It should be noted that viscous shear resistance is inversely proportional to the gap and directly proportional to the area of the part immersed in the fluid and the relative velocity between the two surfaces, so the larger the area and relative velocity of the part immersed in the fluid, the greater the resistance between the moving plate and the casing. The smaller the gap (in other words, the smaller the thickness of the bearing material), the greater the resistance force can be obtained.

This tendency becomes even more pronounced when a high-viscosity polymeric viscous material is used as the viscous material. That is,
This viscous body has non-Newtonian fluid properties, that is, pseudoplastic fluid properties (a phenomenon in which the higher the velocity of the fluid, the easier it is to change from high viscosity to low viscosity and flow, and the degree of increase in resistance force becomes smaller.The resistance force is Approximately of speed
Proportional to the 0.5 to 0.6 power. ), and exhibits more effective damping characteristics for vibrating structures.

When an upward lift force is applied to the vibration of the structure, the vertical movement of the resistance plate that receives the viscous shear resistance force is restrained, so it prevents this upward lift force and maintains a constant gap between the parts where the viscous shear resistance occurs. There is no change (reduction) in the viscous shear resistance of the viscous body due to a change in the gap.

[Effects] The seismic isolation support device for structures of the present invention has the above-mentioned configuration and functions, and therefore has the following unique effects.

According to this device, it is possible to effectively prevent upward lift, which is a problem especially when the structure is lightweight, and to maintain a constant gap in the viscous shear resistance generation area even when upward lift is applied. It can demonstrate damping performance.

According to this device, the viscous shear resistance generating portions are formed at two locations above and below the resistance plate, and a larger viscous shear resistance force than that of the conventional device can be obtained, and the device can be made smaller accordingly.
Therefore, it is particularly effective when applied to lightweight structures.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the seismic isolation support device of the present invention.

Here, G is the superstructure and B is the foundation.

This device H is interposed between the superstructure G and the foundation B, and consists of the following elements.

1 is a casing fixed to foundation B,
A lower plate 2 and a surrounding wall 3 provided on the upper surface of the lower plate 2
and an upper plate 4 which covers the opening of the surrounding wall 3 and has a circular hole-shaped opening 5 in the center. Although the shape of the casing 1 may be any suitable shape, such as a square box or a cylinder, a cylindrical one is shown in this embodiment. The casing 1 assembled from the lower plate 2, surrounding wall 3, and upper plate 4 has sufficient liquid tightness. For this reason, appropriate sealing members (O-rings, gaskets) are arranged on the contact surfaces of these members.

In the casing 1, the upper surface of the lower plate 2 and the lower surface of the upper plate 4 serve as viscous shear resistance surfaces to be described later, and are formed to be smooth (mirror). Furthermore, the lower plate 2 supports the load of the upper structure G, and the upper plate 4 also receives the reaction force of the upper structure G, so it has sufficient strength.

A bolt through hole 6 is bored in the periphery of the casing 1, and a screw hole member 7 is embedded in the base B at a position corresponding to the bolt through hole 6, and a bolt 8 is inserted between the two to open the casing 1. Anchor at base B.

Reference numeral 10 denotes a support that is attached to the upper structure G, and includes a mounting plate 11 and a cylindrical support member that is loosely inserted into the opening 5 of the casing 1 that is integrally fixed to the lower surface of the mounting plate 11 by welding or the like. 12, and a resistance plate 13 integrally fixed to the lower surface of the support member 12 by welding or the like.

The resistance plate 13 is disposed in the internal space of the casing 1 so as to be movable in all directions on a horizontal plane, with a movement range. For this reason, the resistance plate 13 has a shape such as a rectangular plate or a disc shape depending on the shape of the casing 1.
Usually shaped like a disc. Further, the upper and lower surfaces of the resistance plate 13 serve as viscous shear resistance surfaces, and are therefore formed to be smooth (mirror surfaces).

Since this support body 10 supports the load of the upper structure G together with a bearing material to be described later, it is required to have sufficient strength. The support 10 is attached to the upper structure G by tightening a bolt 15 passing through the upper structure G into a screw hole 14 drilled in the mounting plate 11.

20 and 21 are bearing materials (lower bearing material 20, upper bearing material 21) fixed to the upper and lower surfaces of the resistance plate 13. The amount of protrusion of the bearing materials 20 and 21 from the plate surface of the resistance plate 13 is small (about 0.5 mm),
3 collides with the upper and lower surfaces of the internal space of the casing 1 (in other words, the lower surface of the upper plate 4 and the upper surface of the lower plate 2) through these bearing materials 20 and 21, and can move freely in the horizontal direction with sliding. However, vertical movement is restricted.

S1 is a lower minute gap formed by the lower bearing material 20, and S2 is an upper minute gap formed by the upper bearing material 21.

The lower bearing material 20 directly supports the load of the structure, and the upper bearing material 21 receives the upper lift force when it acts on the structure.
It has sufficient strength. For this reason, these bearing materials 20 and 21 are made of a copper alloy, a multilayer material in which a copper-based sintered alloy layer containing graphite is integrally adhered to a thin steel plate, or a synthetic resin.
These are fixed to the upper and lower surfaces of the resistance plate 13 by welding, gluing, embedding, or the like.

The bearing materials 20 and 21 are normally arranged along the shape of the resistance plate 13 along the side edges thereof at appropriate intervals and at the same position above and below, but they may be arranged at different positions in the upper and lower positions. Furthermore, in the case of the lower bearing material 20, one or more can be arranged at the center of the lower surface of the resistance plate 13.

FIG. 2a shows one aspect of the arrangement of the lower bearing material 20, and FIG. 2b shows one aspect of the arrangement of the upper bearing material 21.

25 is a viscous material filled in the casing 1. The viscous material 25 is filled up to the upright portion of the opening 5 of the casing 1, and a flexible cover 27 covering the opening 5 prevents foreign matter from entering and evaporation of the viscous material.

Therefore, inside the casing 1, there are a surface where the bottom surface of the resistance plate 13 faces the top surface of the bottom plate 2, a surface where the top surface of the resistance plate 13 faces the bottom surface of the top plate 4, and a viscosity interposed between these surfaces. The body 25 forms a “viscous shear resistance generating portion”.

The seismic isolation support device of this embodiment operates as follows.

At normal times, the load on the superstructure G is
0 to the lower plate 2 of the casing 1 via the lower bearing material 21 on the lower surface of the resistance plate 13, and the structure is stably supported.

Now, when a sudden external force such as an earthquake acts on a structure, the structure causes forced vibration, and this vibration displacement causes movement of the resistance plate 13 via the support 10. Since the resistance plate 13 faces the lower plate 2 and the upper plate 4 of the casing 1 via the bearing materials 20 and 21 with a small distance S1, S2, the movement of the resistance plate 13 causes relative movement between the two surfaces. occurs, and a viscous shear resistance force is generated by the viscous body 25 interposed between these surfaces. As a result, the structure receives a braking force due to this viscous shear resistance force, and its vibrations are quickly damped.

The upper lift force in addition to the forced vibration of the structure is generated by this device H.
Even if the resistance plate 13 acts on the upper bearing material 2
Since its upward displacement is restrained by the upper plate 4 of the casing 1 via the upper plate 4 of the casing 1, the floating of the resistance plate 13 is prevented, and the gap between the two surfaces, that is, the resistance plate 13
The minute distance between the upper and lower surfaces of and the surfaces of the lower plate 2 and upper plate 4〓S
1 and S2 do not change due to the upper lift force, and the damping function does not deteriorate due to a change in the distance between the two surfaces.

The present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the basic technical idea of the present invention. That is, the following aspects are included within the technical scope of the present invention.

In the illustrated embodiment, the casing 1 is constructed by assembling the lower plate 2, the surrounding wall 3, and the upper plate 4 which are each independent. However, the lower plate 2 and the surrounding wall 3 may be integrated, or the upper plate 4 and the surrounding wall 3 may be integrated. good.

In the illustrated embodiment, the bearing materials 20 and 21 are fixed to the upper and lower surfaces of the resistance plate 13, but it is also possible to fix them to the lower plate 2 and/or the upper plate 4 of the casing 1. However, there is no change in the operation and effect of the present invention.

[Brief explanation of drawings]

1 and 2 show embodiments of the present invention,
Fig. 1 is a longitudinal cross-sectional view of one embodiment, Fig. 2 a, b
1 is a layout diagram of the attachment of a bearing material to a resistance plate. Third
The figure is a sectional view showing the structure of a conventional example. 1...Casing, 2...Lower plate, 4...Upper plate,
10... Support body, 13... Resistance plate, 20, 21...
... Bearing material, 25 ... Viscous body, G ... Upper structure, B
...Fundamentals.

Claims (1)

[Scope of Claims] 1. A support 10 which is vertically disposed from the lower surface of the upper structure G and has a resistance plate 13 horizontally attached to its lower end; It consists of a casing 1 fixed to a foundation B that accommodates the casing 1 so as to be movable in the horizontal direction with a movement area, and a viscous material 25 filled in the casing 1, and the resistance plate 13 has microscopic particles on its upper and lower surfaces. The casing 1 is connected to the casing 1 via bearing materials 20 and 21 that maintain a gap.
The vertical movement is restrained by the lower plate 2 and the upper plate 4, and the lower surface of the resistive plate 13 and the upper surface of the lower plate 2, the upper surface of the resistive plate 13 and the lower surface of the upper plate 4, and their relative orientations. A seismic isolation support device for a structure, characterized in that a viscous shear resistance generating section is formed by a viscous body 25 interposed between two surfaces. 2. The seismic isolation support device for a structure according to claim 1, wherein the bearing materials 20 and 21 are fixed to the resistance plate 13.