JP2002266936A - Base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation device capable of propagating no unnecessary vibration to a construction under a preferable vibration isolation effect and being optimized to expect enhancement of a general purpose of use. SOLUTION: The vibration isolation device has a vibration isolating support 10 of which the lower end is connected to the ground G side and an upper end is connected to the construction A side; and a damper 20 of which one end is connected to the ground G side and the other end is connected to the construction A side. The vibration isolating support 10 is integrally formed by alternately superposing a plurality of soft layers 11 and hard layers 12 and the soft layers 11 are formed by a natural rubber or a synthetic rubber containing silica being not subjected to a surface processing as a filler. The damper 20 comprises an oil damper and is set to reduce a generation rate of a damping force when a load exceeding approximately 80% of the maximum load, i.e., a rupture limit is applied to the oil damper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device, and more particularly to an improvement in a seismic isolation device that prevents a ground-side roll caused by an earthquake or the like from propagating to a building.

[0002]

2. Description of the Related Art As a seismic isolation device for preventing a roll from the ground side caused by an earthquake or the like from propagating to a building side, there have been proposed, for example, as shown in FIGS. .

[0003] Incidentally, the same applies to the case of the present invention, but in the place shown in Figs.
Includes an artificially formed foundation (not shown) and, although not shown, is referred to herein because the seismic isolation device may be located on the middle floor of building A. The ground G also includes the structure A.

[0004] The structure A refers to a structure constructed above the ground G. The structure A mentioned here includes a wooden structure, a mortar structure, and a reinforced concrete structure. Instead of pointing to a house,
It mainly consists of reinforced concrete, steel-framed reinforced concrete, and even steel-frame structures, and refers to middle- and high-rise buildings and super-high-rise buildings whose weight is extraordinarily large compared to ordinary houses.

The conventional seismic isolation device shown in FIGS. 5 and 6 has a seismic isolation bearing 1 disposed between the ground G side and the building A side, and is arranged in parallel with the seismic isolation bearing 1. And a damper 2 disposed therein.

The seismic isolation bearing 1 includes a plurality of soft layers 1a.
And the hard layer 1b are alternately laminated and integrated, and the soft layer 1a often contains an appropriate filler in a rubber component mainly composed of natural rubber or synthetic rubber.

The hard layer 1b functions to regulate the bending of the soft layer 1a. In many cases, a steel sheet is selected from the viewpoint of manufacturing cost and maintenance.
The integration with the soft layer 1a is realized by using an adhesive or the like.

On the other hand, the damper 2 is generally known as an elasto-plastic damper, and functions to prevent the seismic isolation bearing 1 from being unnecessarily bent when the above-mentioned rolling is input. In the figure, it is assumed that the spring is made of a considerably soft helical spring made of steel, and in FIG. 6, it is made of a curved pillar made of lead.

Therefore, according to each of the seismic isolation devices shown in FIGS. 5 and 6 as a conventional example, a roll caused by an earthquake or the like from the ground G side is absorbed by the seismic isolation bearing 1, and the structure A
Side will not be propagated.

When the roll from the ground G side is input to the seismic isolation bearing 1 with a large amplitude and greatly bent, the elastic-plastic damper, for example, the range of the elastic limit of the helical spring As a result, the above-mentioned roll of large amplitude is attenuated.

[0011]

However, it has been pointed out that the above-described conventional seismic isolation device has the following problems.

First, in the seismic isolation bearing 1 constituting the conventional seismic isolation device, it should be satisfied that, from the characteristics of the soft layer 1a, the rolling from the ground G side is not propagated to the building A side. There is a problem that the effect cannot be obtained.

That is, when the soft layer 1a in this type of seismic isolation bearing 1 is made of only natural rubber or synthetic rubber, it is preferable from the viewpoint that the roll from the ground G side is not propagated to the building A side. I can say.

However, even if a plurality of soft layers 1a made of only natural rubber or synthetic rubber are alternately laminated and integrated with a plurality of hard layers 1b to form a seismic isolation bearing 1,
Since there is almost no moderate viscosity, that is, almost no viscosity leading to the generation of damping force, it is not possible to expect energy absorption in the lateral rolling from the ground G side.

Next, in the case of an elastic-plastic damper as a damper 2 constituting a conventional seismic isolation device, for example, when this is formed of a steel helical spring, it is proportional to the magnitude of the roll input from the ground G side. As a result, the force (hysteresis) due to the history of the spring, that is, the damping force is increased.

Therefore, when the spring force is set such that the damping force can be generated accurately even for the roll of the expected magnitude, the spring force is easily set to have a strong spring force.
Therefore, the spring force becomes generally hard, and a satisfactory effect cannot be obtained in preventing the roll from the ground G side from propagating to the building A side.

In addition, the elasto-plastic damper made of a helical spring cannot be reused as it is when it exceeds its allowable limit, that is, the deformation limit, and requires replacement with a so-called new one. The same applies to the case where the elasto-plastic damper is made of a lead column.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to prevent unnecessary vibrations from propagating to a building under a preferable seismic isolation effect. An object of the present invention is to provide a seismic isolation device that is optimal for expecting an improvement in versatility.

[0019]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, a construction of the present invention basically comprises a seismic isolation bearing having a lower end connected to a ground side and an upper end connected to a building side. A damper having one end connected to the ground side and the other end connected to the building side, and the seismic isolation bearing is formed by alternately stacking a plurality of soft layers and hard layers and being integrated, When the soft layer contains silica that has not been surface-treated as a filler in natural rubber or synthetic rubber, and the damper is made of an oil damper and a load exceeding approximately 80% of the maximum load at which the oil damper has a breaking limit is applied. Is set so as to reduce the rate of occurrence of the damping force.

In the above structure, more specifically, the soft layer is composed of 100 to 100 parts by weight of a rubber component mainly composed of natural rubber or synthetic rubber and 40 to 100 parts by weight of silica not subjected to surface treatment as a filler. Is assumed to be contained.

At this time, it is preferable that a natural rubber or a synthetic rubber constituting the rubber component has a shear elastic modulus of 0.43 (N / mm ² ) or less at 100% shear deformation.

Incidentally, the oil damper has a cylinder body which is laid horizontally and whose bottom end is connected to either the ground side or the construction side, and whose tip is grounded while the base end side is inserted so as to be able to protrude and retract. And a rod body connected to the other side of the rod body or the construction side, and when the rod body comes and goes with respect to the cylinder body, the rod body is slidably housed in the cylinder body and has a proximal end. The extension damping valve disposed on the piston defining the extension oil chamber and the compression oil chamber in the cylinder while being connected to the cylinder, or the compression damping valve disposed in the cylinder body, the predetermined extension side and the compression side It is preferable that each damping force is formed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below on the basis of the illustrated embodiment. The seismic isolation device according to the present invention, as shown in FIG. A seismic isolation bearing 10 having a lower end connected to the ground G side and an upper end connected to the building A side, similarly to the conventional seismic isolation device;
The damper 20 has one end connected to the ground G side and the other end connected to the building A side.

Incidentally, even in the present invention, the seismic isolation bearing 10 is formed by integrally laminating a plurality of soft layers 11 and hard layers 12 alternately, and the hard layer 12 reduces the bending of the soft layer 11. It is said that, as well as the function of regulating, the integration of the soft layer 11 and the hard layer 12 is embodied by using an adhesive or the like as in the conventional case.

It should be noted that a steel sheet is also selected for the hard layer 12 from the viewpoint of manufacturing cost and maintenance, as in the conventional case.

In the present invention, although not shown, the soft layer 11 is composed of 100 to 100 parts by weight of a rubber component mainly composed of natural rubber or synthetic rubber and 40 to 100 parts by weight of silica not surface-treated as a filler. Parts.

Since the soft layer 11 contains silica which has not been subjected to surface treatment in addition to the rubber component, compared to a soft layer containing only a rubber component not containing a filler, even if it contains a filler, As compared with a soft layer containing silica that has been subjected to surface treatment, the viscosity increases, so that a damping force can be expected to be generated during deformation.

Further, since the soft layer 11 has a smaller reinforcing property than carbon black, as shown by a broken line in FIG. 2, a known high attenuation using carbon black and resin to increase the viscosity. Compared with rubber, as shown by the solid line in FIG.

That is, the characteristics of the soft layer containing no filler and the case of the soft layer containing silica which has been surface-treated even if the filler is contained are shown by the broken lines in FIG. In contrast, the characteristics of the soft layer 11 containing silica which has not been surface-treated as a filler, while having a substantially linear shape without a width, are represented by solid lines in FIG. Therefore, the soft layer 11 according to the present invention also has a viscosity that leads to the generation of a damping force, that is, a hysteresis.

In forming the soft layer 11, that is, in setting the above-mentioned parts by weight,
In the illustrated embodiment, 0.4% at 100% shear deformation.
100 parts by weight of a rubber component mainly composed of natural rubber having a shear modulus of 3 (N / mm ² ) or less, and approximately 70 parts by weight of silica not subjected to surface treatment as a filler. A damping property is obtained.

As a result, in this seismic isolation bearing 10,
When the amplitude of the roll from the ground G side is low compared to the narrow amplitude, the soft layer 11 easily bends and absorbs the vibration from the ground G side, and does not propagate the vibration to the building A side. Needless to say, at this time, a damping action is also performed, and effective seismic isolation can be realized.

If the amount of silica exceeds 100 parts by weight with respect to 100 parts by weight of the rubber component, the unvulcanized viscosity of the rubber composition becomes high, and the processability deteriorates. .

As described above, the seismic isolation bearing 10 according to the present invention is formed by integrating the soft layer 11 having a preferable damping characteristic with the hard layer 12, so that the seismic isolation bearing 1 is
a, that is, the inconvenience of infinitely flexing can be avoided as compared with the case where only the rubber component is used, and the rigid layer 12 integrated with the flexible layer 11 regulates the flexing of the flexible layer 11. Therefore, when the vibration has a large amplitude, the vibration is absorbed by setting the soft layer 11 to a state where the soft layer 11 is flexed to the limit.

Next, according to the present invention, the damper 20 is made of an oil damper, and as will be described later in detail, the damper 20 generates a damping force having characteristics that cannot be obtained by the above-mentioned conventional helical spring as the damper 2. It is of course advantageous in that the space formed between the side of the building A and the side of the ground G, which may be narrow in many cases, can be arranged with a margin.

In the present invention, the characteristics of the oil damper are set so as to exhibit bilinear characteristics as shown in FIG. 4, and the expansion and contraction speed of the oil damper is approximately 32 cm / sec. When a load of approximately 80% of the limit maximum load is applied, the generation rate of the damping force is reduced, that is, a high cut action is set to a state where a low damping force is generated.

In the drawing, the oil damper 20 is laid horizontally and has a bottom end connected to the building A side, and is inserted through the cylinder body 21 so that the base end can be protruded and retracted. While having a rod body 22 whose tip is connected to the ground G side.

Although not shown, when the rod 22 protrudes and retracts from the cylinder 21, the cylinder 21
An expansion damping valve disposed on a piston which defines the expansion oil chamber and the compression oil chamber in the cylinder body 21 while being slidably housed therein and connected to the base end of the rod body 22, or
The compression-side damping valve disposed in the cylinder body 21 is configured to generate a predetermined extension-side and compression-side damping force.

Therefore, in the seismic isolation device according to the present invention formed as described above, a preferable seismic isolation can be realized by cooperation of the seismic isolation bearing 10 and the oil damper as the damper 20.

[0039]

As described above, in the present invention, the soft layer constituting the seismic isolation bearing is not subjected to the surface treatment as a filler to 100 parts by weight of the rubber component mainly composed of natural rubber or synthetic rubber. Since the silica is contained in an amount of 40 to 100 parts by weight, the soft layer itself is attenuated compared to a soft layer containing no filler and a soft layer containing silica which is surface-treated even if it contains a filler. It will have a favorable viscosity that will lead to the generation of force.

Compared with a known high-damping rubber using carbon black and a resin to increase damping, the rubber has high flexibility, and preferably has a shear strain of 1 of the base-isolated bearing.
When the shear modulus at 00% is 0.43 N / mm ² or less, for example, when the roll from the ground side is low in amplitude compared to the narrower amplitude, the soft layer is easily bent and the soft layer flexes easily from the ground side. Absorbing the vibration and not propagating the vibration to the building side, it also has a damping action at this time, so that an effective seismic isolation can be realized.

Since the hard layer integrated with the soft layer functions to restrict the bending of the soft layer, it is possible to avoid the infinite bending phenomenon of the soft layer, and it is possible to prevent the vibration having a large amplitude. In other words, the vibration is absorbed by setting the soft layer to a state of being bent to the limit.

On the other hand, according to the present invention, the oil damper as the damper is set so as to exhibit bilinear characteristics.
At 2 cm / sec, almost 80% of the maximum load, which is the breaking limit
When the load of (1) is applied, the generation rate of the damping force is reduced, that is, a high-cut action is performed to reduce the damping force.

As a result, when the roll from the ground side is, for example, at a high speed compared to a large amplitude, the seismic isolation bearing absorbs the vibration from the ground side as much as possible, and the vibration is transmitted to the building side. When the vibration exceeds the permissible limit of the seismic isolation bearing without propagating the vibration, the damper performs a predetermined damping operation and realizes effective seismic isolation.

In addition, according to the present invention, since the damper is made of an oil damper,
When vibration exceeding the allowable limit is input, the elasto-plastic damper, which is a conventional damper, is destroyed, making it impossible to reuse the damper. There is.

As a result, according to the present invention, it is possible to prevent unnecessary vibrations from propagating through the building under a preferable seismic isolation effect, which is optimal for expecting improvement in versatility.

[Brief description of the drawings]

FIG. 1 is a front view, partially in section, showing a state in which a seismic isolation device according to the present invention is disposed between a ground side and a building side.

FIG. 2 is a view showing a shear strain characteristic with respect to a shear elastic modulus of a soft layer constituting a seismic isolation bearing according to the present invention.

FIG. 3 is a view showing a shear strain characteristic with respect to a load of a soft layer constituting a seismic isolation bearing according to the present invention.

FIG. 4 is a diagram showing a damper damping characteristic according to the present invention.

FIG. 5 is a diagram showing an example of a conventional seismic isolation device, similarly to FIG.

FIG. 6 is a view showing another example of the conventional seismic isolation device, similarly to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Seismic isolation bearing 11 Soft layer 12 Hard layer 20 Damper 21 Cylinder body 22 Rod body A Construction G Ground

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16F 9/50 F16F 9/50 15/023 15/023 A 15/08 15/08 D (72) Inventor Yasuo Tsurugi 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (72) Inventor Osamu Takahashi 4-38-13, Honcho, Nakano-ku, Tokyo Inside Structural Planning Laboratory Co., Ltd. (72) Inventor Noritaka Sasaki 1183 Rokubu, Inami-cho, Kako-gun, Hyogo F-term (reference) 3K048 AA02 AC04 AC05 AD05 BA08 BE01 DA01 EA38 3J059 AA08 BA43 GA42 3J069 AO50

Claims (2)

[Claims] 1. A seismic isolation bearing having a lower end connected to the ground side and an upper end connected to the building side, and a damper having one end connected to the ground side and the other end connected to the building side. The seismic isolation bearing is formed by alternately laminating a plurality of soft layers and hard layers, and the soft layer contains natural rubber or synthetic rubber containing untreated silica as a filler, and the damper has A seismic isolation device comprising an oil damper, wherein the oil damper is set so as to reduce the rate of occurrence of damping force when a load exceeding approximately 80% of a maximum load acting as a breaking limit is applied. 2. The rubber composition according to claim 1, wherein the soft layer contains 40 to 100 parts by weight of a silica not subjected to surface treatment as a filler in 100 parts by weight of a rubber component mainly composed of natural rubber or synthetic rubber. Seismic device