JP2001074093A - Base isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid oscillation of a structure due to strong wind and to effectively perform a base isolation function when an earthquake occurs. SOLUTION: A rolling support body 4 to absorb vibrational energy by relatively displacing by the vibrational energy generated in the horizontal direction is furnished between a building 2 and a ground 3, and this rolling support body is constituted of a support member 6 fixed on the building and to support it by projecting a ball bearing 5 downward free to roll and a pan member 8 fixed on the ground and on an upper surface of which a conical recessed part 7 to support the ball bearing free to roll is formed. An inclined surface of the recessed part of this pan member 8 is rectilinear, and inclination θ of the relative rectilinear inclined surface is found and formed by a previously decided computing element α<=g(sinθ.cosθ+μcos2θ)<=β (wherein, acceleration of earthquake motion α=8 gal, β=140 gal, gravity acceleration g=980 gal. Additionally, μis a friction coefficient of the rolling support body.).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a seismic isolation device,
In particular, the present invention relates to a seismic isolation device that supports relatively lightweight structures such as precision equipment in addition to wooden buildings.

[0002]

2. Description of the Related Art Conventionally, various seismic isolation devices have been proposed for seismic isolation of relatively lightweight structures such as detached houses.

[0003] For example, a seismic isolation device disclosed in Japanese Patent Application Laid-Open No. 9-221935 is shown in FIG.
Seismic isolation means 23 interposed between the ground structure 21 and the ground structure 22 to suppress the response of the ground structure 21 to the seismic motion.
And a damper device 24 interposed between the ground 22 and the controller 25 controls the damper device 24 to increase the damping force when the wind speed acting on the above-mentioned ground structure 21 exceeds a set value. Is what you do.

According to the seismic isolation device 20 described above, the ground structure 21 is swung by the wind and swung by the controller 2.
5 can be avoided by the damper device 24 controlled by the control unit 5, and the seismic isolation means 23 can effectively perform the seismic isolation function when an earthquake occurs.

However, since electric and hydraulic pressures are automatically controlled by an electric signal or the like, there has been a problem that costs such as facility costs and maintenance costs are increased. In addition, there was a problem that control was lost due to a power failure or the like.

[0006] Further, as shown in FIG.
A slide bearing 33 interposed between the base member 32 and the base member 32 to slidably support the upper structure 31 in the horizontal direction; A rolling bearing 34 movably supported is provided. The rolling bearing 34 includes a rollable spherical body 35 and a receiving plate 37 having a concave curved surface 36 formed on the upper surface thereof for rollingly mounting the spherical body 35. A seismic isolation device 30 is known.

According to the seismic isolation device 30, the rolling bearing 34 can extend the seismic isolation cycle, and the sliding bearing 33 can attenuate the vibration.

However, if the upper structure 31 is light, as shown in FIG. 4, the yield load may be smaller than the wind load. When trying to increase (structure weight × friction coefficient), the upper structure 101 has to be heavier, so that there has been a problem that the cost increases.

Further, as shown in FIG. 5, a rolling bearing body 44 that is relatively displaced by vibration energy generated in the horizontal direction and absorbs the vibration energy in the horizontal direction,
A trigger mechanism 45 having an elasto-plastic body 46 that undergoes elasto-plastic deformation in a state of being rich in extensibility when the horizontal vibration energy is less than a predetermined value and plastically breaks down when the vibration energy is equal to or more than a predetermined value,
There is known a seismic isolation device 41 interposed between an upper structure 42 and a ground 43 in parallel.

According to the seismic isolation device 41, the stiffness of the upper structure 42 is suppressed by the high initial rigidity of the elasto-plastic body 46 of the trigger mechanism 45 during a strong wind or a small earthquake, and the elasto-plastic body 46 is deformed during a moderate earthquake. The vibration is damped by elasto-plastic deformation, and in the case of a large earthquake, the elasto-plastic body 46 is plastically destroyed, and the vibration period of the upper structure 42 can be lengthened by the rolling bearing 44.

However, due to a large earthquake or the like,
In the case where 6 breaks, the elasto-plastic body 46 has to be replaced, and there is a problem that labor and cost for the operation are required.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and has a simple configuration in which a trigger function and a seismic isolation function are integrated to prevent the structure from swinging due to strong wind. It is an object of the present invention to provide a seismic isolation device that can avoid a collision and effectively perform a seismic isolation function when an earthquake occurs.

[0013]

According to the seismic isolation device of the present invention which achieves the above object, a relative vibration is generated between a structure and a foundation or between an upper structure and a lower structure by vibration energy generated in a horizontal direction. In a seismic isolation device having a rolling bearing body that displaces and absorbs the vibration energy, the rolling bearing body is fixed to a structure or an upper structure, and supports a rolling member by rollingly protruding downward and supporting the rolling member. Components,
And a saucer member having a conical recess formed on an upper surface fixed to the foundation or the lower structure and rotatably supporting the rolling member. The inclined surface of the recess of the saucer member is linear and linear. The inclination angle θ of the inclined surface is a predetermined calculation element, α ≦ g (sin θ · cos θ + μcos ² θ) ≦ β (provided that the acceleration of seismic motion α = 8 gal, β = 140 gal, and the gravitational acceleration g = 980 gal. , Μ are the frictional coefficients of the rolling bearings).

According to such a seismic isolation device, when the acceleration of the seismic motion is 8-140 gal, that is, when the seismic intensity floor of the Meteorological Agency becomes less than 5, the rolling member of the rolling bearing body rolls on the inclined surface of the concave portion of the receiving plate member. Since the movement starts, the seismic isolation function can be exhibited effectively. Therefore, it does not oscillate in a strong wind, so that the livability is improved.

In the seismic isolation device of the present invention, the acceleration α of the seismic motion is preferably 25 gal, and β is preferably 80 gal. As a result, the seismic intensity function of the Japan Meteorological Agency can exhibit the seismic isolation function when the seismic intensity level is less than 5, so that the seismic isolation function can be exhibited without impairing the livability.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a seismic isolation device according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1 (a), the seismic isolation device of the present invention is interposed between a building 2, which is a relatively lightweight structure, and a ground 3, which is a foundation, and is generated in a horizontal direction. A rolling bearing 4 is provided which absorbs the horizontal vibration energy by being relatively displaced by the vibration energy.

As shown in FIG. 1 (b), the rolling bearing member 4 is fixed to the building 2 and supports a ball bearing 5 which is a rolling member so as to rollably protrude downward and support it.
And a saucer member 8 having a conical recess 7 fixed to the ground 3 and rotatably supporting the ball bearing 5 and having an upper surface formed therein.
It is composed of Therefore, the bearing member 6 that has moved in the horizontal direction via the ball bearing 5 can return to the original position along the concave portion 7, that is, the deepest position of the concave portion 7 by the gravitational action of the building 2. Thereby, the building 2 can completely return to the original position.

The inclined surface of the concave portion 7 of the receiving member 8 is formed linearly. The inclination angle θ of this linear inclined surface is determined by a predetermined calculation element, α ≦ g (sin θ · cos θ + μcos ² θ) ≦ β (provided that the acceleration of seismic motion α = 8 gal, β = 140 gal, and the gravity acceleration g = 980 gal Where μ is the coefficient of friction of the rolling bearing 4).

Here, the deepest position of the concave portion 7 of the pan member 8,
That is, the ball bearing 5 has an initial speed of 0 (zero) from the center.
When the force α rises, the force for lowering by gravity is g (sin θ · cos θ) and the force for pushing up the ball bearing 5 is μg cos ² θ, so that α = g (sin θ · cos θ + μcos ² θ ). This equation of motion is described in
It is disclosed in Japanese Patent Publication No. 101021.

Therefore, the acceleration α of the earthquake motion is set to 8 to 14
If it is set to 0 gal, the ball bearing 5 of the rolling bearing 4 starts rolling on the inclined surface of the concave portion 7 of the saucer member 8 at the seismic intensity floor 5 of the Meteorological Agency, so that the seismic isolation function can be exhibited effectively. it can. Thereby, since it does not oscillate in a strong wind, livability is improved. In addition, the seismic intensity floor 3 of the Japan Meteorological Agency has an acceleration α of seismic motion of 8 to 25 gal, and the tableware on the shelf is
In a state where sound may be heard, seismic intensity floor 4 has an acceleration α of seismic motion of 25 to 80 gal, suspended objects shake greatly, tableware on shelves makes sound, and a poorly seated ornament falls down. Indicates a certain state. Therefore, if the acceleration α of the seismic motion is set to 25 gal and β to 80 gal, the seismic intensity level of the Japan Meteorological Agency will be able to exhibit the seismic isolation function at 4, and the seismic isolation function will be exhibited without impairing the livability Can be done.

The seismic isolation operation of the seismic isolation device according to the present invention thus configured will be described. The recess 7 of the pan member 8
The inclination angle θ of the linear inclined surface is set to the acceleration of the seismic motion of the seismic intensity floor 4 of the Japan Meteorological Agency of 60 gal.

When horizontal vibration energy is applied to the building 2 by a strong wind or a small earthquake of seismic intensity 1 or 2 (earthquake acceleration 0.8 to 8 gal) by the Japan Meteorological Agency, the gravity of the ball bearing 5 of the rolling bearing 4 decreases due to the gravity. The force of gutter (g (sinθ ・
cos θ) is larger than the force (μg cos ² θ) for pushing up the ball bearing 5, so that the rolling bearing 4
Suppresses the shaking of the building 2.

Even if the building 2 receives horizontal vibration energy due to a moderate earthquake of seismic intensity 3 at the Meteorological Agency (acceleration of seismic motion of 8 to 25 gal), the force (g (sin θ) of the ball bearing 5 to drop due to gravity. · Cos θ)) is the force (μg cos ² θ) to push up the ball bearing 5
Since it is larger, the rolling bearing 4 suppresses the shaking of the building 2.

Further, when horizontal vibration energy is applied to the building 2 by a moderate earthquake of seismic intensity 4 at the Meteorological Agency (acceleration of seismic motion of 25 to 80 gal), the ball bearing 5 is pushed up when the acceleration of the seismic motion is 80 gal or more. Since the force (μgcos ² θ) to be applied is larger than the force (g (sinθ · cosθ)) of the ball bearing 5 that tends to decrease due to gravity, the building 2 and the ground 3 are relatively moved by the rolling bearing 4. Displaced and horizontal vibration energy is absorbed.
Thereby, the shaking of the building 2 can be attenuated.
Further, the ball bearing 5 moved along the linear inclined surface of the concave portion 7 of the receiving member 8 returns to its original position along the linear inclined surface of the concave portion 7 due to the gravitational action of the building 2, that is, the deepest position of the concave portion 7. You can go back to Therefore, building 2
It will be possible to completely return to the original position.

When the building 2 is subjected to horizontal vibration energy due to a large earthquake having a seismic intensity of 5 or more by the Japan Meteorological Agency (acceleration of ground motion of 80 gal or more), the ball bearing 5
Force (μg cos ² θ) is lower than the force (g (sin θ)
・ Cos θ)) is much larger than building 2 and ground 3
Is relatively displaced by the rolling support 4,
The vibration cycle of the building 2 is made longer. In addition, similarly to the case of the middle earthquake, the building 2 can be completely returned to the original position by the rolling bearing 4.

In the preferred embodiment of the seismic isolation device of the present invention described above, the horizontal vibration energy is absorbed only by the rolling bearings 4. However, the present invention is not limited to this, and the building can be slid in the horizontal direction. Rubber bearings that support large loads by supporting a sliding bearing body that supports the vertical direction and a rigid spring in the vertical direction, and can be largely deformed in the horizontal direction by a soft spring unique to rubber, or damping of oil dampers, lead dampers, etc. You may use together with a mechanism etc.

The place of installation of the seismic isolation device of the present invention is not limited to the space between the structure and the ground. For example, it may be installed between the 8th and 9th floors of the building that will be the upper structure and the lower structure. It can be applied to seismic isolation of relatively lightweight structures such as precision equipment.

Such a seismic isolation device of the present invention not only has an anti-vibration effect, but also has an anti-vibration effect if the vibration is transmitted from the device that generates the vibration to the foundation.

[0030]

As described above, according to the seismic isolation device of the present invention, it is possible to prevent the structure from oscillating due to strong wind, and to effectively prevent the structure from being affected by an earthquake that adversely affects the structure. Because it can perform the seismic isolation function, comfortable livability can be ensured. In addition, since the trigger function and the seismic isolation function are integrated with a simple configuration, the construction is easy, and the installation can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a view showing a preferred embodiment of a seismic isolation device of the present invention, wherein FIG. 1 (a) is an explanatory view showing an installed state, and FIG.
Is a detailed explanatory view of a rolling bearing.

FIG. 2 is an overall view showing a conventional seismic isolation device.

FIG. 3 is an overall view showing a conventional seismic isolation device.

FIG. 4 is a graph showing a relationship between a load and a displacement when a sliding bearing of the seismic isolation device of FIG. 3 receives horizontal vibration energy.

FIG. 5 is an overall view showing a conventional seismic isolation device.

[Explanation of symbols]

 2. Building (structure) 3. Ground (foundation) 4. Rolling bearing 5. Ball bearing (rolling member) 6. Bearing Member 7 ... Recess 8 ... Receiver member

Claims (2)

[Claims] 1. A seismic isolation device having a rolling bearing between a structure and a foundation, or between an upper structure and a lower structure, which is relatively displaced by vibration energy generated in a horizontal direction to absorb the vibration energy. The rolling bearing body is fixed to the structure or the upper structure, and a rolling member that protrudes downward so as to freely roll and supports the rolling member, and the rolling member fixed to the foundation or the lower structure. And a receiving member having a conical concave portion formed on an upper surface of the receiving member so that the member can roll freely.The inclined surface of the concave portion of the receiving member is linear and the inclination angle θ of the linear inclined surface is Predetermined calculation elements, α ≦ g (sin θ · cos θ + μcos ² θ) ≦ β (provided that the acceleration of seismic motion α = 8 gal, β = 140 gal, and the gravitational acceleration g = 980 gal. Here, μ is the rolling bearing. Friction A seismic isolation device characterized by being formed by a coefficient. 2. The acceleration α of the ground motion is 25 gal and β is 8
The seismic isolation device according to claim 1, wherein the seismic isolation device is 0 gal.