JPH09112068A - Vertical direction base isolation method and base isolating device and three dimensional base isolating method and base isolating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical direction base isolating method, etc., to be practiced at the lowest part of a structure to protect the structure from a directly downward earthquake in the vertical direction and a three dimensional base isolating method, etc., to be practiced at a lower part outer periphery of the structure to protect the structure even from an earthquake in the horizontal direction. SOLUTION: A structure is supported by a vertical direction base isolating device A, vertical displacement of the structure caused by an earthquake is allowed by derricking motion of a support rod 4 constituting the vertical direction base isolating device A and restoring force of a restoring spring 5 interlocked with it, and earthquake energy in the vertical direction is damped by a damper 6 constituting the vertical direction base isolating device A. A horizontal direction base isolating device B is set between a lower part of the structure and an outer peripheral structural body, and eathquake energy in the horizontal direction is damped by a damper 9 in the horizontal direction constituting the horizontal direction base isolating device B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for protecting a structure (generally generically referred to as a building, exhibit, OA equipment, etc.) from a large earthquake, especially an up-down vertical earthquake. Vertical seismic isolation method, etc. implemented at the bottom of the building, and three-dimensional seismic isolation method, etc. implemented on the lower outer periphery of the structure to protect the structure from horizontal earthquakes.

[0002]

2. Description of the Related Art Many seismic isolation devices for protecting structures from earthquakes have been developed, but most of them are seismic isolation devices for horizontal earthquakes. For example, seismic isolation devices using laminated rubber bearings have been developed and widely implemented.
Although three-dimensional seismic isolation devices that can respond to vertical earthquakes have been attracting attention in recent years, they are still in the development stage.

[0003]

The conventional technology of the seismic isolation device for horizontal earthquakes cannot be applied to seismic isolation for vertical earthquakes. The reason is that the self-weight of the structure body always acts on the seismic isolation device,
This causes the following problems. The restoring force element such as the spring of the seismic isolation device is always in a high stress state, causing creep and relaxation.

The restoring spring is largely deformed due to the weight of the structure. Moreover, since the restoring spring is further deformed in the event of an earthquake, a large allowable deformation amount is required. In order to solve the problems (1) to (3), it is necessary to increase the rigidity of the restoring spring, and as a result, the vibration cannot be lengthened and the seismic isolation effect cannot be obtained. If the above problems are simply solved, a trigger function may be provided. However, in that case, in addition to the problem of
It is also inconvenient because it creates a new problem that it does not recover automatically after the earthquake.

Therefore, the objects of the present invention are as follows.
The problem is that the rigidity of the structure is made relatively high until it sinks due to the weight of the structure, and when the structure is subjected to an earthquake in the up and down direction, and when it further sinks, the rigidity becomes relatively high. Utilizing the non-linear restoring force characteristics that makes it smaller and displaces softly, the restoring spring does not sink much due to the weight of the structure without increasing the rigidity of the restoring spring, and the force applied to the restoring spring when loaded by its own weight is reduced, After the earthquake, the vertical seismic isolation method and seismic isolation device and the three-dimensional seismic isolation method and seismic isolation device can be automatically restored to the original position to reliably reduce the vertical seismic force and the horizontal seismic force. To provide.

[0006]

As means for solving the above-mentioned problems of the prior art, the vertical seismic isolation method according to the invention described in claim 1 is: a) A structure is mounted by the vertical seismic isolation device A. Support me,
The vertical displacement of the structure caused by the earthquake is allowed by the undulating motion of the support rod 4 which constitutes the vertical seismic isolation device A and the restoring force of the restoring spring 5 which interlocks with it. B) The vertical seismic energy is It is characterized in that it is damped by the damper 6 or 6'constituting the directional seismic isolation device A.

The vertical seismic isolation apparatus according to the second aspect of the present invention is installed between the lower bottom surface 10 of the structure and the foundation 12 to support the structure, and the vertical direction is applied to the structure. Seismic isolation device A for attenuating the seismic energy of: a) A horizontal support plate 3 for horizontally movably supporting the structure is horizontally provided on the lower bottom surface 10 of the structure, b). The structure is supported by a parallel link mechanism P formed by connecting a plurality of support rods 4 which are appropriately inclined with respect to the vertical direction between the support plate 3 and the foundation 12, and the damper 6 is attached to the parallel link mechanism P. Or 6'is attached, c) One end of the restoring spring 5 that is arranged to restore the inclination of the support rod 4 is connected to the end of the parallel link mechanism P, and the other end of the restoring spring 5 is Must be connected to the peripheral structure , D) Vertical displacement of the structure caused by the earthquake is allowed by the undulating motion of the support rod 4 and the restoring force of the restoring spring 5 interlocked with it, and the vertical seismic energy is attenuated by the damper 6 or 6 '. It is characterized by being a configuration.

The three-dimensional seismic isolation method according to the invention described in claim 3 is: a) The structure is supported by the vertical seismic isolation device A,
The vertical displacement of the structure caused by the earthquake is allowed by the undulating motion of the support rod 4 which constitutes the vertical seismic isolation device A and the restoring force of the restoring spring 5 which interlocks with it. B) The vertical seismic energy is Damping by the damper 6 or 6'constituting the direction seismic isolation device A, c) The horizontal seismic isolation device B is installed between the lower part of the structure and the outer peripheral structure, and the horizontal seismic energy is horizontal. It is characterized in that it is damped by a horizontal damper 9 that constitutes the directional seismic isolation device B.

A three-dimensional seismic isolation device according to the invention described in claim 4 is: a) a vertical seismic isolation device A for reducing the vertical seismic force applied to a structure, and a horizontal seismic force for the seismic isolation device. And a horizontal seismic isolation device B. b) The vertical seismic isolation device A has a horizontal support plate 3 for horizontally movably supporting the structure. Bottom surface 1
A plurality of support rods 4 which are provided horizontally at 0 and in which the support plate 3 and the foundation 12 are appropriately inclined with respect to the vertical direction.
The structure is supported by a parallel link mechanism P formed by connecting with each other, and the damper 6 or 6 ′ is attached to the parallel link mechanism P.
Is attached, one end of the restoring spring 5 is connected to the end of the parallel link mechanism P in an arrangement capable of restoring the inclination of the support rod 4, and the other end of the restoring spring 5 is connected to the outer peripheral structure, The vertical displacement of the structure caused by the earthquake is allowed by the undulating motion of the support rod 4 and the restoring force of the restoring spring 5 interlocked therewith, and the vertical seismic energy is damped by the damper 6 or 6 ′. c) In the horizontal seismic isolation device B, one end of each of the horizontally oriented second restoration spring 8 and the second damper 9 is connected to the lower portion of the structure, and each one end of the second restoration spring 8 and the second damper 9 is connected. It is characterized in that it is connected to the outer peripheral structure, and the seismic energy in the horizontal direction is damped by the damping force of the second damper 9.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is preferably implemented as a three-dimensional seismic isolation device which is a combination of a vertical seismic isolation device A and a horizontal seismic isolation device B. In some cases, the vertical seismic isolation device A is used. It is carried out only in. The vertical seismic isolation device A is installed especially between the lower bottom surface 10 of the building 1 and the foundation 12 to support the building 1 and reduce the vertical seismic force applied to the building 1. The horizontal seismic isolation device B is installed between the lower portion of the building 1 and the underground side wall surface 13 and reduces the horizontal seismic force applied to the building 1. Further, the vertical seismic isolation device A and the horizontal seismic isolation device B are also implemented in a mode in which they are installed on the floor of a building or the like in order to protect exhibits and OA equipment from an earthquake.

According to the present invention, the building 1 is supported by the vertical seismic isolation device A, and the vertical displacement of the building 1 caused by an earthquake causes the supporting rod 4 constituting the vertical seismic isolation device A to move up and down. Permitting the restoring force of the interlocking restoring spring 5, the vertical seismic energy is damped by the damper 6 that constitutes the vertical seismic isolation device A (claim 1). In the vertical seismic isolation device A, a horizontal support plate 3 for movably supporting the building 1 in a horizontal direction is provided on the lower bottom surface 1 of the building 1.
0, and the parallel link mechanism P is formed by connecting the support plate 3 and the foundation 12 with a plurality of support rods 4 that are appropriately inclined with respect to the vertical direction. The building 1 is supported by P, and a damper 6 arranged vertically is attached inside the parallel link mechanism P. Note that the vertical seismic isolation device A is also implemented in a mode in which a horizontal damper 6'is attached to the outside of the parallel link mechanism P instead of the vertical damper 6. Then, one end of a restoring spring 5 having an arrangement capable of restoring the inclination of the support rod 4 is connected to an end portion of the parallel link mechanism P, and the other end of the restoring spring 5 is connected to the outer peripheral structure by a pin 2 or the like. (Claim 2). Therefore, when the vertical seismic force F is applied to the support plate 3 due to an earthquake, the outer support rod 4 tilted at the angle θ has its upper end supported by the restoring spring 5 as shown in FIG. On the other hand, the pin 2 at the lower end is used as a fulcrum to tilt (fall down) to the position of the angle θ ′ indicated by reference numeral 4 ′, for example. that time,
The support plate 3 forming the parallel link mechanism P is horizontally displaced (translated) to the lower position indicated by reference numeral 3'and sinks. next,
As described above, the more slanted support rod 4 ′ receives the restoring force of the stretched restoring spring 5 ′ to perform the restoring operation, and the sunk support plate 3 floats upward so that the upper and lower parts of the building 1 are lifted. Displacement is allowed. At this time, the seismic energy in the vertical direction is attenuated by the damper 6 or the damper 6 ′ attached to the parallel link mechanism P. Since the restoring force of the restoring spring 5 is non-linear but elastic, the support rod 4 after being isolated in response to the vertical seismic force F is restored to the initial position of inclination angle = θ. Be stable (equilibrium).

FIG. 5 shows that the restoring spring 5 has a rigidity of 1.0 t / c.
The relation between the vertical seismic force F and the vertical displacement x of the supporting plate 3 (building 1) when m is shown is shown based on the calculation result. According to the figure, the seismic force F is 30
It can be seen that when a weight of t is loaded, the support plate 3 sinks about 1.4 cm due to the weight of the building 1. At this time, since the restoring spring 5 extends by about 8 cm, the force constantly applied to the restoring spring 5 is about 8 t. Assuming a case where a slight vertical vibration occurs under the condition of own weight loading, the equalized rigidity is about 2.9 t / c from the figure.
m (the cycle is 0.65 seconds). On the other hand, in the case of directly using the spring for vertical seismic isolation without using this device,
It can be seen that a restoring spring of about 2.9 t / cm is required to make it equivalent to this device, and it sinks by 10 cm or more under its own weight. Further, a force of 30t always acts on the restoring spring. In other words, according to the vertical seismic isolation device A, the support rod 4 bears most of the dead weight of the building 1, so that the force constantly acting on the restoring spring 5 can be reduced, and the relaxation of the restoring spring 5 can be reduced. The amount of sinking due to its own weight is greatly reduced.

The relationship between the vertical seismic force F and the vertical displacement x of the support plate 3 (building 1) will be derived below from mathematical expressions. As its premise, the following symbols shown in FIG. 6 are used. F ... Vertical seismic force x ... Vertical displacement of support plate (3) L ... Length of support rod (4) S ... Natural length of restoring spring (5) A ... Restoring spring (5) from foundation (12) Height to the outer edge B… Distance from the basement wall side surface (13) to the lower end of the support rod (4) C… Height from the foundation (12) to the support plate (3) Under these conditions, the restoring spring 5 naturally The length S is obtained from the following [Equation 1].

[0014]

(Equation 1) Here, if the restoring spring 5 is extended by δ, the following expression [Formula 2] is obtained.

[0015]

(Equation 2) At this time, the force applied to the restoring spring 5 is Kδ, where K is the spring constant. To consider the balance of power, see FIG. 6B.
When the lengths of α and β of the two sides of the triangle shown in (3) are obtained, the following equation [Formula 3] is obtained.

[0016]

(Equation 3) From the balance of power, the following [Equation 4] is obtained.

[0017]

(Equation 4) here,

[0018]

(Equation 5) Therefore, if δ is obtained from the equation [2], F can be calculated from the equation [4]. Therefore, if the relational expression between F and x is shown, the following [Equation 6] is obtained.

[0019]

(Equation 6) Therefore, the building 1 has a relatively high rigidity up to the point where the building 1 sinks due to its own weight due to the large supporting force of the support rod 4 in a posture close to the vertical, and when the building 1 further sinks due to the vertical seismic force F, it is supported. A non-linear elasticity (softening) characteristic that the rigidity becomes softer as the inclination of the rod 4 becomes larger is exhibited, and this characteristic can be effectively used for seismic isolation.

Further, by installing the horizontal seismic isolation device B between the lower part of the building 1 and the outer peripheral structure, the horizontal seismic energy is attenuated by the damper 9 of the seismic isolation device B ( Claim 3). In the horizontal seismic isolation device B, one end of each of the second restoring spring 8 and the second damper 9 arranged horizontally is connected to the lower portion of the building 1 by a pin 2 or the like, and the second restoring spring 8 and the second damper 9 are connected. Since the other end of each is connected to the outer peripheral structure (claim 4), the seismic energy in the horizontal direction is attenuated by the second damper 9. Thus, according to the three-dimensional seismic isolation apparatus of the present invention, it is possible to efficiently and surely lengthen the period even when a vertical earthquake occurs, as well as a horizontal earthquake.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
FIG. 1 schematically shows a case where the three-dimensional seismic isolation device of the present invention is applied to a building 1. This three-dimensional seismic isolation system is composed of a vertical seismic isolation system A implemented at the bottom of the building 1 and a horizontal seismic isolation system B implemented at the outer periphery of the lower part of the building 1.

The vertical seismic isolation device A includes a lower bottom surface 1 of the building 1.
Four pieces (however, the number is not limited to this) are installed between 0 and the foundation 12. This vertical seismic isolation device A includes a support plate 3 and a plurality of support rods 4 forming a parallel link mechanism P.
And a restoring spring 5 that gives a restoring force to the parallel link mechanism P.
And a damper 6 for damping the seismic energy.

The support plate 3 may be any one as long as it supports the building 1 in a horizontally movable state, and it is provided on the sliding plate 3a (about half the width of the building 1) and the sliding plate 3a as shown in FIG. A plurality of rollers 3b ... And an oiles plate (not shown) are preferably used. The support plates 3 are provided on the lower bottom surface 10 of the building 1 in a horizontal arrangement.

The support rod 4 is made of a steel frame member having a length of 50 cm and has an inclination angle θ of about 20 ° with respect to the vertical direction.
(See FIG. 3), and is movably connected to the support plate 3 and the foundation 12 by pins 2 (or ball joints). Therefore, in the illustrated example, a parallel link mechanism P is formed in which the two left and right support rods 4, 4 and the upper and lower support plates 3 and the base 12 are pin-connected, and the parallel link mechanism P is formed.
Building 1 is supported by.

The damper 6 is attached to the upper support plate 3 and the lower base 12 by a pin 2 in the vertical direction at a substantially central position inside the parallel link mechanism P.
It should be noted that, like the damper 6 ′ shown in FIG. 4, the damper 6 has an outer end (or an upper end of the outer support rod 4 (not shown)) of the support plate 3 forming the parallel link mechanism P and the underground wall surface 13. It is also possible to connect with the pin 2 in a substantially horizontal direction.

The restoring spring 5 has a natural length of 70 cm and a spring force of 1 t / cm. The restoring spring 5 is provided at the upper end of the outer supporting rod 4 so that the inclination of the supporting rod 4 of the parallel link mechanism P can be restored. The inner end is movably connected by a pin 2, and the outer end of the restoring spring 5 is pin-connected to the underground side wall surface 13 on the outer periphery of the building 1. The horizontal seismic isolation device B includes a second restoring spring 8 and a second damper 9 in order to reduce the horizontal seismic force applied to the building 1. The horizontal seismic isolation device B is installed between the lower side wall portion 11 and the underground side wall surface 13 of the building 1 and has two corners on the outer periphery of the building 1 as shown in FIG. There are 8 locations in total.

The second restoring spring 8 is arranged horizontally, the inner end of which is movably connected to the lower side wall portion 11 of the building 1 by a pin 2, and the outer end of which is pinned to the underground side wall surface 13 on the outer periphery of the building 1. It is movably connected at 2. Similarly to the second restoring spring 8, the second damper 9 is also arranged horizontally, each inner end is pin-connected to the lower side wall portion 11 of the building 1, and the outer end thereof is pinned to the underground side wall surface 13 on the outer periphery of the building 1. It is connected.

[0028]

According to the three-dimensional seismic isolation method and the like according to the present invention, the rigidity is made relatively high up to the point where the building is sunk by its own weight, and the rigidity is increased when an earthquake is applied to the building and then it is further sunk. Since the nonlinear restoring force characteristic that is relatively small and deforms softly is used, seismic isolation effect is exerted by reliably damping the seismic energy in the horizontal direction as well as in the vertical direction. The force applied to the restoring spring when the building is loaded with its own weight is small
Since the relaxation of the restoring spring is reduced and the amount of subsidence of the supporting plate due to the weight of the building is small, a long period seismic isolation device, which was difficult to design in the past, is designed.

[Brief description of the drawings]

FIG. 1 is a front view showing a state where a three-dimensional seismic isolation device is installed in a building.

FIG. 2 is a plan view showing a state in which a horizontal seismic isolation device is installed in a building.

FIG. 3 is an explanatory diagram showing an operating state of the vertical seismic isolation device.

FIG. 4 is an explanatory view showing a different configuration of the vertical seismic isolation device.

FIG. 5 is a graph of vertical displacement-load curve.

6A and 6B are explanatory views for leading the relationship between the vertical seismic force and the vertical displacement of the support plate.

[Explanation of symbols]

 A Vertical seismic isolation device B Horizontal seismic isolation device P Parallel link mechanism 2 Pins 3 Base plate 4 Support rod 5 Restoring spring 6 Damper 8 Second restoring spring 9 Second damper 12 Foundation

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeo Reiwaki 1-5 Otsuka, Inzai-cho, Inba-gun, Chiba Prefecture Takenaka Corporation Technical Research Institute

Claims (4)

[Claims] 1. A) A structure is supported by a vertical seismic isolation device, and the vertical displacement of the structure caused by an earthquake is caused by an undulating motion of a support rod that constitutes the vertical seismic isolation device and a restoring spring interlocked with it. B) The vertical seismic energy is attenuated by the damper that constitutes the vertical seismic isolation device.
Vertical seismic isolation method. 2. A seismic isolation device which is installed between a lower bottom surface of a structure and a foundation to support the structure, and which reduces the vertical seismic force applied to the structure, comprising: a) a structure A horizontal support plate for horizontally movably supporting the object is horizontally provided on the lower bottom surface of the structure, and b) a plurality of support plates and the foundation are appropriately inclined with respect to the vertical direction. The structure is supported by the parallel link mechanism formed by connecting with the support rod of, and the damper is attached to the parallel link mechanism, and c) One end of the restoring spring is arranged so that the inclination of the supporting rod can be restored. The structure is connected to the end of the parallel link mechanism, and the other end of the restoring spring is connected to the outer peripheral structure, d) The vertical displacement of the structure caused by the earthquake is linked to the undulating motion of the support rod and it. Restoring force of restoring spring More allowed, seismic energy in the vertical direction, characterized in that it is configured to attenuate by the damper, vertical seismic isolation device. 3. A) The structure is supported by a vertical seismic isolation device, and the vertical displacement of the structure caused by an earthquake is caused by the undulating motion of a support rod which constitutes the vertical seismic isolation device and the restoring spring interlocking with the motion. Allowed by the restoring force, b) Vertical seismic energy is attenuated by the damper that constitutes the vertical seismic isolation device, and c) Horizontal seismic isolation device is installed between the lower part of the structure and the outer peripheral structure. The three-dimensional seismic isolation method is characterized in that the horizontal seismic energy is attenuated by the horizontal damper that constitutes the horizontal seismic isolation device. 4. A three-dimensional seismic isolation device comprising a vertical seismic isolation device that reduces the vertical seismic force applied to a structure and a horizontal seismic isolation device that reduces the horizontal seismic force. B) In the vertical seismic isolation device, a horizontal support plate for horizontally movably supporting the structure is horizontally provided on the lower bottom surface of the structure, and a vertical space is provided between the support plate and the foundation. The structure is supported by a link mechanism formed by connecting a plurality of support rods that are appropriately inclined with respect to the direction, a damper is attached to the parallel link mechanism, and the parallel link is arranged so that the inclination of the support rod can be restored. One end of the restoring spring is connected to the end of the mechanism, and the other end of the restoring spring is connected to the outer peripheral structure. To the resilience of The vertical seismic energy is allowed to be absorbed by the damper, and c) the horizontal seismic isolation device has a horizontally oriented second restoring spring and one end of the second damper at the bottom of the structure. The other ends of the second restoring spring and the second damper are connected to the outer peripheral structure, and the seismic energy in the horizontal direction is attenuated by the damping force of the second damper. Dimensional seismic isolation device.