JP2011099538A - Vertical base isolation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vertical base isolation system optionally setting an allowable imposed load over a wide range, and applicable to a building with large mass. <P>SOLUTION: The vertical base isolation system 1 includes a liquid reservoir tank 2 with a building piston insertion port 21a and a seismic isolation piston insertion port 22a, a building piston part 3 freely slidably inserted in the liquid reservoir tank from the building piston insertion port 21a and arranged below the building B, a seismic isolation piston part 4 freely slidably inserted in the liquid reservoir tank from the seismic isolation piston insertion port 22a, and a vibration absorbing part 5 arranged outside the liquid reservoir tank and connected to the seismic isolation piston part, and attenuating a vibration when the seismic isolation piston part is vibrated. The liquid reservoir tank is configured to become a sealed container by the respective insertion of the building piston part and the seismic isolation piston part. Moreover, a cross sectional area of the building piston part and that of the seismic isolation piston part are set to be different in value from each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vertical seismic isolation system, and more particularly to a vertical seismic isolation system that isolates vibrations in the vertical direction of a building.

  The seismic isolation device that suppresses the vibration of the building in the event of an earthquake includes a horizontal seismic isolation device that reduces vibration in the horizontal direction using laminated rubber and sliding bearings, etc., and a spring such as an air spring placed at the bottom of the building. There is a vertical seismic isolation device that reduces vibration in the vertical direction by elastic support. In addition, a three-dimensional seismic isolation device (see Patent Literature 1 and Patent Literature 2) in which a horizontal seismic isolation device and an upper and lower seismic isolation device are arranged side by side, and elastically displaced in a direction perpendicular to the expansion and contraction direction to provide seismic isolation action. There is also known a three-dimensional seismic isolation device (see Patent Document 3) that performs a plurality of seismic isolation means to be diagonally installed between a base to be isolated and a foundation to perform horizontal and vertical isolation.

JP 2001-82542 A JP 2001-41283 A JP-A-8-177970

  By the way, since a strong pitching occurs in a direct type large earthquake, a vertical seismic isolation system that can be applied not only to a building having a small mass but also to a building having a large mass is required. In the vertical seismic isolation device that reduces the vibration in the vertical direction by elastically supporting the building with the spring arranged at the bottom of the building, it is possible to elastically support the building even in a large mass building by increasing the rigidity of the spring However, if the rigidity of the spring is increased, it becomes difficult to make the natural vertical vibration period of the building longer than the vertical vibration period of the seismic motion, and the seismic isolation performance decreases. For this reason, the vertical seismic isolation device currently in practical use cannot be applied to a building having a relatively small allowable burden load that allows vertical seismic isolation and a large mass.

  This invention is made | formed in view of the said situation, and it aims at providing the vertical seismic isolation system which can obtain what can be applied to a building with a large mass.

  In order to solve the above-described problems and achieve the object, the vertical seismic isolation system of the present invention has at least two openings having different cross-sectional areas, a liquid storage tank for storing liquid therein, and the 2 A piston for a building that is slidably inserted into the liquid storage tank from one of the two openings and disposed below the building; and an exemption that is slidably inserted into the liquid storage tank from the other of the two openings. A seismic piston part, and a vibration absorbing part that is arranged outside the liquid storage tank and connected to the seismic isolation piston part, and attenuates the vibration when the seismic isolation piston part vibrates, The liquid storage tank becomes a sealed container by inserting each of the building piston part and the seismic isolation piston part, and the cross sectional area of the building piston part and the cross sectional area of the seismic isolation piston part are Different values Characterized in that there.

  Another vertical seismic isolation system according to the present invention is characterized in that, in the vertical seismic isolation system, a cross-sectional area of the building piston portion is smaller than a cross-sectional area of the seismic isolation piston portion.

  Still another vertical seismic isolation system according to the present invention is characterized in that, in the vertical seismic isolation system, a cross-sectional area of the building piston portion is larger than a cross-sectional area of the seismic isolation piston portion.

  Still another vertical seismic isolation system according to the present invention is the above-described vertical seismic isolation system, wherein the vibration absorbing portion uses an elastic force in a direction to cancel the vibration when the seismic isolation piston portion vibrates. It has an elastic deformation part added to a piston part, and an attenuation part which is arranged in parallel with the elastic deformation part and attenuates the simple vibration when the elastic deformation part makes a simple vibration.

  In the vertical seismic isolation system of the present invention, by appropriately selecting the ratio of the cross-sectional area of the seismic isolation piston part to the cross-sectional area of the building piston part and the rigidity of the vibration absorbing part, the natural vertical vibration period of the building It can be longer than the vertical vibration period. Moreover, the pressure of the liquid in the liquid storage tank at the time of use becomes an allowable burden load. Therefore, in the vertical seismic isolation system of the present invention, by appropriately selecting the ratio of the cross-sectional area of the seismic isolation piston part to the cross-sectional area of the building piston part, the rigidity of the vibration absorbing part, and the pressure resistance of the liquid storage tank, An allowable burden load that allows vertical seismic isolation can be selected, and a system that can be applied to a building having a large mass can be obtained as well as one that can be applied to a building having a small mass.

FIG. 1 is a partial sectional view schematically showing an example of the vertical seismic isolation system of the present invention. FIG. 2 is a partial cross-sectional view schematically showing a state during the base isolation operation of the vertical base isolation system shown in FIG. FIG. 3 is a graph showing the relationship between the ratio of the natural vertical vibration period of the building to the ground motion period of the harmonic ground motion and the absolute acceleration response magnification. FIG. 4 is a partial cross-sectional view schematically showing an example of a vertical seismic isolation system in which the cross-sectional area of the building piston portion is larger than the cross-sectional area of the seismic isolation piston portion. FIG. 5 is a partial cross-sectional view schematically showing an example of a vertical seismic isolation system in which a top flange portion is provided in a building piston portion. FIG. 6 is a partial cross-sectional view schematically showing an example of a vertical seismic isolation system in which a seismic isolation cylinder portion is provided in a liquid storage tank with its central axis horizontal.

  Hereinafter, embodiments of the vertical seismic isolation system of the present invention will be described in detail with reference to the drawings. Note that the vertical seismic isolation system of the present invention is not limited to the following forms.

(Embodiment 1)
FIG. 1 is a partial sectional view schematically showing an example of the vertical seismic isolation system of the present invention. The vertical seismic isolation system 1 shown in the figure is a system for isolating the vertical vibration of the building B, and includes a liquid storage tank 2, a building piston 3, a seismic isolation piston 4, and a vibration absorber 5. I have. Hereinafter, after explaining each component of the vertical seismic isolation system 1 in detail, the seismic isolation operation of the vertical seismic isolation system 1 will be described in detail.

  The liquid storage tank 2 has at least two openings having different cross-sectional areas, specifically, a building piston insertion port 21a and a seismic isolation piston insertion port 22a, and stores liquid L such as water therein. . The building piston insertion port 21a is at the upper end of the building cylinder portion 21 having a vertical center axis C1, and the seismic isolation piston insertion port 22a is at the upper end of the seismic isolation cylinder portion 22 having a vertical center axis C2. Each is located. The building cylinder part 21 and the seismic isolation cylinder part 22 communicate with each other by a connecting flow path part 23. The liquid L is stored in the liquid storage tank 2 prior to use of the vertical seismic isolation system 1.

  The building piston part 3 has, for example, a circular horizontal cross-sectional shape, and is slidably inserted into the liquid storage tank 2 from the building piston insertion port 21a. Inserted into the bottom of the building. The seismic isolation piston portion 4 has, for example, a circular horizontal cross-sectional shape, and is slidably inserted into the liquid storage tank 2 from the seismic isolation piston insertion port 22a. Specifically, it is inserted into the liquid storage tank 2 from the seismic isolation cylinder 22. The seismic isolation piston part 4 has a piston main body 41 inserted into the seismic isolation cylinder part 22 and a top flange part 42 formed at the upper end of the piston main body 41.

  In the vertical seismic isolation system 1, the cross-sectional area of the building piston 3 and the cross-sectional area of the seismic isolation piston 4 are selected to be different from each other. The cross-sectional area of the part 4 is larger. Therefore, the effective cross-sectional area of the seismic isolation cylinder 22 is larger than that of the building cylinder 21. The liquid storage tank 2 becomes an airtight container by inserting each of the building piston 3 and the seismic isolation piston 4.

  The vibration absorbing portion 5 is disposed outside the liquid storage tank 2 and connected to the seismic isolation piston portion 4, and attenuates this vibration when the seismic isolation piston portion 4 vibrates. In the vertical seismic isolation system 1, the elastic deformation portion 6, the upper connection portion 7 a, the lower connection portion 7 b, the attenuation portion 8, the attenuation upper connection portion 9 a, and the attenuation lower connection portion 9 b are used. A vibration absorbing unit 5 is configured.

  When the seismic isolation piston portion 4 vibrates in a direction parallel to the central axis C2 of the seismic isolation cylinder portion 22 due to seismic motion or the like, the elastic deformation portion 6 generates an elastic force in a direction to cancel this vibration. Add to 4. The elastic deformation portion 6 is composed of, for example, one coil spring or a plurality of coil springs connected in parallel. The upper end of the elastic deformation portion 6 is connected to the top flange portion 42 of the seismic isolation piston portion 4 by the upper connecting member 7a, and the lower end is the lower side. It is connected to the foundation structure S by the connecting member 6b.

  The attenuating portion 8 is constituted by an air damper, for example, and is arranged in parallel with the elastic deformation portion 6. The damping part 8 is an air spring having a cylinder part 81 whose one end is closed and a piston part 82 inserted into the cylinder part 81. The piston part 82 is connected to the upper connecting member 7a by the damping upper connecting member 9a, and the cylinder part 81 is connected to the lower connecting member 7b by the lower damping connecting member 9b. The attenuating portion 8 applies a downward elastic force to the upper connecting member 7a via the damping upper connecting member 9a when the elastic deforming portion 6 is extended, and the damping upper connecting member 9a is applied when the elastic deforming portion 6 contracts. An upward elastic force is applied to the upper connecting member 7a via the upper connecting member 7a to attenuate the simple vibration when the elastically deforming portion 6 makes a simple vibration. As a result, the vertical vibration of the building B is attenuated.

  The vertical seismic isolation system 1 including the above-described components is arranged on the foundation structure S, and the building B is constructed above the building piston 3 by connecting the lower part to the upper part of the building piston 3. Or relocated. For example, after building the foundation structure S, the seismic isolation control system 1 is constructed to store the liquid L such as water in the liquid storage tank 2, and the building B is filled on the liquid storage tank 2 as necessary. Built or relocated. The building B is supported by the vertical seismic isolation system 1 while floating on the liquid L via the building piston 3.

  During normal times, that is, when an external force that vibrates in the vertical direction is not applied to the building B, the pressure applied to the liquid L from the building piston 3 and the pressure applied to the liquid L from the seismic isolation piston 4 balance each other. As a result, the building B remains stationary. The elastic deformation portion 6 and the attenuation portion 8 cause initial deformation according to the mass of the building B. On the other hand, when an external force that vibrates in the vertical direction, for example, an earthquake pitch, is applied to the building B, the vertical seismic isolation system 1 starts the seismic isolation operation.

  FIG. 2 is a partial cross-sectional view schematically showing a state during the base isolation operation of the vertical base isolation system shown in FIG. Since each component shown in FIG. 2 has already been described with reference to FIG. 1, description thereof is omitted here. The reference sign “y” in FIG. 2 represents the downward ground motion acceleration when the earthquake is pitched, the white arrow indicates the direction of the ground motion acceleration y, and the reference sign “x” is the addition of the ground acceleration y to the building B. The downward displacement amount of the building B when it is applied, the reference symbol “α” represents the ratio of the cross-sectional area of the seismic isolation piston part 4 to the cross-sectional area of the building piston part 3. In FIG. 2, each of the building B and the top flange portion 42 at rest is drawn with imaginary lines.

  When the earthquake is pitched, the vertical seismic isolation system 1 and the building B are damped and oscillated. The building piston 3 moves up and down, and the liquid L moves in the liquid storage tank 2 along with this, and the seismic isolation piston 4 moves up and down, but when the seismic isolation piston 4 is displaced upward, it vibrates. A downward elastic force is applied to the seismic isolation piston portion 4 from the absorption portion 5, and an upward elastic force is applied to the seismic isolation piston portion 4 from the vibration absorption portion 5 when the seismic isolation piston portion 4 is displaced downward. The vertical vibration of the building B is absorbed by the vertical seismic isolation system 1. That is, the building B is subjected to vertical seismic isolation.

At this time, the damped vibration is the downward ground motion acceleration y [m / s ² ], the mass of the building B M [kg], the density of the liquid L ρ [kg / m ³ ], and the building The sectional area of the piston part 3 is A [m ² ], the rigidity (spring constant) of the elastic deformation part 6 is k [kN / m ² ], the damping coefficient of the damping part 8 is c [kN · s / m], and the building The second-order differential value (acceleration) of the downward displacement x [m] of B is a [m / s ² ], and the first-order differential value (velocity) of the downward displacement x of the building B is v [m / s. If the gravitational acceleration is g [m / s ² ], it is expressed by the following equation (1). Further, the natural vertical vibration period T of the building B when the building B is performing the damped vibration of the formula (1) is expressed by the following formula (2).
Ma + [ρgA {1+ (1 / α)} + (k / α ² )] x + (c / α ² ) v = −My (1)
T = 2π [M / [ρgA {1+ (1 / α)} + (k / α ² )]] ^1/2 (2)

  As shown in FIG. 2, the displacement amount of the top flange portion 42 with respect to the downward displacement amount x of the building B is “−x / α”, and the displacement amount of the elastic deformation portion 6 at this time is also “−x / α”. It becomes. Accordingly, when the cross-sectional area of the seismic isolation piston part 4 is made larger than the cross-sectional area of the building piston part 3 and the ratio α is made larger than 1, the amount of displacement of the elastic deformation part 6 with respect to the downward displacement x of the building B “−x / α” decreases. From this, it can be seen that if the ratio α is larger than 1, the rigidity k of the elastically deformable portion can be increased. If the elastic deformation part 6 with large rigidity k is used, the absolute acceleration which arises in the building B at the time of a pitching can be made small.

  Further, it can be seen from the equation (2) that when the ratio α is larger than 1, the natural vertical vibration period T of the building B is lengthened even if the rigidity k of the elastically deforming portion 6 is large. From this, it can be understood that the natural vertical vibration period T of the building B can be arbitrarily selected by appropriately selecting the ratio α and the rigidity k of the elastically deformable portion 6. By making the natural vertical vibration period T longer than the vertical vibration period of the ground motion, the vertical seismic isolation of the building B is realized. In the vertical seismic isolation system 1, since the load weight of the liquid storage tank 2 is equal to the pressure of the liquid L, the allowable burden load can be arbitrarily selected by appropriately selecting the pressure resistance of the liquid storage tank 2. it can. Therefore, even if the mass of the building B is large, it is possible to obtain the vertical seismic isolation system 1 that isolates the building B vertically by increasing the pressure resistance of the liquid storage tank 2.

For example, if the specifications of the vertical seismic isolation system 1 are selected as shown in Table 1, the allowable load is 4053 kN / m ² that greatly exceeds the allowable load of the conventional vertical isolator, and the mass is 1.0 ×. The natural vertical vibration period T of the 10 ⁷ kg building B can be increased to 2.0 s.
Table 1
Liquid density ρ: 1.0 × 10 ³ kg / m ³
Cross section A of building piston; 24.2m ²
Liquid pressure; 4053 kN / m ²
Stiffness k of elastic deformation part: 987 × 10 ⁶ kN / m
Ratio α; 100
Mass of building M: 1.0 × 10 ⁷ kg
Building natural vertical vibration period T; 2.0 s
*: The deformed elastic part is a PC steel bar with a diameter of 32mm and a length of 4.7m (SBPR1080 / 1230)
Assume a spring made by collecting 28226.

  If the natural vertical vibration period T of the building B is lengthened to 2.0 [s], as shown in FIG. 3, the building B is moved in the vertical direction by the harmonic ground motion with the ground motion period Ty of 1.0 [s]. Since the absolute acceleration response magnification when vibrating is about 0.33, the vertical acceleration isolation system 1 can reduce the response acceleration to about 1/3, and a large vertical isolation effect can be obtained. In FIG. 3, the absolute acceleration response magnification is obtained by setting the attenuation coefficient c of the attenuation unit 8 to 0.02.

(Embodiment 2)
In the vertical seismic isolation system 1 of the first embodiment, the cross-sectional area of the building piston 3 is made smaller than the cross-sectional area of the seismic isolation piston 4 and the ratio α is selected to be larger than 1. Even if the ratio α is selected to be a value smaller than 1, it is possible to obtain a vertical seismic isolation system capable of performing vertical isolation of the building B.

  FIG. 4 is a partial cross-sectional view schematically showing an example of a vertical seismic isolation system in which the cross-sectional area of the building piston portion is larger than the cross-sectional area of the seismic isolation piston portion. In the vertical seismic isolation system 1A shown in the figure, the cross-sectional area of the building piston 3 is made larger than the cross-sectional area of the seismic isolation piston 4, and the seismic isolation piston 4 with respect to the cross-sectional area of the building piston 3 is shown. 1 except that the cross-sectional area ratio α is selected to be a value smaller than 1 and the elastically deforming portion 6 is configured using a spring having a very long period during simple vibration. It has the same configuration as the vertical seismic isolation system 1 shown. In FIG. 4, the same reference numerals as those used in FIG. 1 are attached to the constituent elements having the same functions as the constituent elements shown in FIG.

  In this vertical seismic isolation system 1A, since the cross-sectional area of the building piston 3 is larger than the cross-sectional area of the seismic isolation piston 4, the building B having a mass larger than the allowable load of the spring used for the elastic deformation portion 6 is used. It can be supported. For example, when the elastically deforming portion 6 is configured by using a spring having a period of 20 [s] at the time of simple vibration, the stiffness k of this spring is a very small value, but the seismic isolation with respect to the cross-sectional area of the building piston portion 3 is performed. By setting the ratio α of the cross-sectional area of the piston part 4 to 0.01, the natural vertical vibration period T of the building B can be set to about 2.0 [s]. That is, it is possible to perform the vertical seismic isolation of the building B having a mass 100 times the allowable load of the spring.

  In the vertical seismic isolation system 1A, the number of springs required for the vertical seismic isolation of the building B can be reduced compared to the vertical seismic isolation system 1 in FIG. It is also possible to reduce compared to the above. That is, an economical seismic isolation system can be constructed.

  The vertical seismic isolation system of the present invention has been described with reference to the embodiment. However, as described above, the vertical seismic isolation system of the present invention is not limited to the above-described system. For example, the cross-sectional shape of each of the building piston portion and the seismic isolation piston portion in the vertical seismic isolation system of the present invention can be appropriately selected from a circular shape, a square shape, and the like. The cross-sectional shape of the building piston portion and the seismic isolation piston portion These cross-sectional shapes may be the same as or different from each other. In addition, the number of piston parts for building and the number of piston parts for seismic isolation can each be one or more than two, and can be selected as appropriate according to the scale of the building subject to vertical seismic isolation. Is possible. When the liquid storage tank is provided with a building cylinder part and a seismic isolation cylinder part and the number of at least one cylinder part is plural, the liquid storage tank has these cylinder parts branched from one connecting flow path part. It becomes a structure.

  Further, the number of seismic isolation piston parts may be the same as the number of building piston parts, or may be different from the number of building piston parts. Of the openings provided in the liquid storage tank, the number of openings into which the building pistons are inserted corresponds to the number of building pistons, and the number of openings into which the seismic isolation pistons are inserted is exempted. The number depends on the number of seismic piston parts.

  When a liquid storage tank is provided with a plurality of building cylinder parts and a plurality of seismic isolation cylinder parts, the planar arrangement of each of the plurality of building cylinder parts and the seismic isolation cylinder parts depends on the planar shape of the building and the site of the building. It is possible to select appropriately according to the planar shape and the like. When a plurality of seismic isolation cylinders are provided in the liquid storage tank, one vibration absorbing part can be connected to one seismic isolation cylinder, or one vibration absorbing part can be connected to a plurality of seismic isolation parts. It can also be connected to the cylinder part for a work, and can also connect a some vibration absorption part to one cylinder part for seismic isolation. From the standpoint of bringing the building to a stationary state as soon as possible after the earthquake's pitching has subsided, it is preferable to arrange at least one attenuation portion in parallel with one elastic deformation portion.

  If necessary, a top flange portion can be provided in the building piston portion. FIG. 5 is a partial cross-sectional view schematically showing an example of a vertical seismic isolation system in which a top flange portion is provided in a building piston portion. The vertical seismic isolation system 1B shown in the figure has the same configuration as that of the vertical seismic isolation system 1 shown in FIG. 1 except that the building piston 3 includes a piston body 31 and a top flange 32. Have. Among the constituent elements shown in FIG. 5, those common to the constituent elements shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1 and description thereof is omitted. By providing the top flange portion 32 in the building piston 3, it becomes easy to stably support the building B.

  An opening into which the building piston is inserted is arranged in the liquid storage tank so that the opening faces downward, and the building piston is supported vertically so that each of the building and the liquid storage tank is supported from below. It is also possible to configure a seismic system. However, from the viewpoint of minimizing the load applied to the building piston, it is preferable to arrange the opening into which the building piston is inserted in the liquid storage tank so that the opening faces upward. Further, when the building cylinder portion is provided in the liquid storage tank, it is preferable to provide the building cylinder portion so that the central axis thereof is vertical from the viewpoint of reducing the load applied to the building cylinder portion as much as possible. The seismic isolation cylinder can be provided in the liquid storage tank with its central axis horizontal or oblique.

  FIG. 6 is a partial cross-sectional view schematically showing an example of a vertical seismic isolation system in which a seismic isolation cylinder portion is provided in a liquid storage tank with its central axis horizontal. The vertical seismic isolation system 1C shown in the figure has a seismic isolation cylinder portion 22 disposed in the liquid storage tank 2 with its central axis C2 horizontal, and a top flange portion 42 (see FIG. 1), and the upper and lower seismic isolation system 1 shown in FIG. 1 except that the elastically deforming portion 6 and the damping portion 8 are horizontally arranged and vibrate in the horizontal direction during damping vibration. It has the same composition as. In FIG. 6, the same constituent elements as those shown in FIG. 1 and the constituent elements having the same functions are denoted by the same reference numerals as those used in FIG.

  In the vertical seismic isolation system 1C, since the cross-sectional area can be increased by expanding the diameter of the seismic isolation piston portion 4 in the vertical direction, the vertical isolation system 1C shown in FIG. Compared to a system in which the diameter of the piston portion 4 is expanded in the horizontal direction to increase the cross-sectional area, it is easy to construct a system in which the seismic isolation piston portion 4 has a large cross-sectional area even if the site of the building B is small.

  The vertical seismic isolation system of the present invention can be provided side by side with a horizontal seismic isolation device that reduces horizontal vibration using laminated rubber, a sliding bearing, or the like. In the case where the horizontal seismic isolation device is provided, for example, a new horizontal surface device is connected below the liquid storage tank. By installing the vertical seismic isolation system of the present invention together with the horizontal seismic isolation device, it is possible to construct a three-dimensional seismic isolation system that absorbs seismic motion in all directions, and it is highly safe not to collapse even if a direct earthquake occurs. It becomes possible to build a building. The vertical seismic isolation system of the present invention can be variously modified, modified and combined in addition to the above.

1, 1A, 1B, 1C Vertical seismic isolation system 2 Liquid storage tank 21 Cylinder part for building 21a Piston insertion port 22 Seismic isolation cylinder part 22a Piston insertion port 23 Connection flow path part 3 Piston part for building 31 Piston body 32 Top flange Part 4 Seismic isolation piston part 41 Piston body 42 Top flange part 5 Vibration absorbing part 6 Elastic deformation part 8 Damping part B Building C1 Center axis of building cylinder part C2 Center axis of seismic isolation cylinder part

Claims (4)

A liquid storage tank having at least two openings having different cross-sectional areas, and storing liquid therein;
A piston for a building, which is slidably inserted into the liquid storage tank from one of the two openings and disposed below the building;
A seismic isolation piston portion slidably inserted into the liquid storage tank from the other of the two openings;
A vibration absorbing portion disposed outside the liquid storage tank and connected to the seismic isolation piston portion to attenuate the vibration when the seismic isolation piston portion vibrates;
With
The liquid storage tank becomes a sealed container by inserting each of the building piston part and the seismic isolation piston part, and the cross sectional area of the building piston part and the cross sectional area of the seismic isolation piston part are Vertical seismic isolation system characterized by different values.   The vertical seismic isolation system according to claim 1, wherein a cross-sectional area of the building piston portion is smaller than a cross-sectional area of the seismic isolation piston portion.   2. The vertical seismic isolation system according to claim 1, wherein a cross-sectional area of the building piston portion is larger than a cross-sectional area of the seismic isolation piston portion. The vibration absorber is
An elastic deformation portion that applies an elastic force to the seismic isolation piston portion in a direction to cancel the vibration when the seismic isolation piston portion vibrates;
An attenuating part that is arranged in parallel with the elastically deforming part and attenuates the single vibration when the elastically deforming part undergoes a simple vibration;
The vertical seismic isolation system according to any one of claims 1 to 3, characterized by comprising:

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