JP2023079957A - Base isolation structure and construction method thereof - Google Patents

Abstract

To provide a base isolation structure capable of reassuring high adhesion between a base isolation device and a base isolation foundation while having excellent strength and rigidity.SOLUTION: A base isolation structure 1 comprises a lower base isolation foundation 20, a base isolation device 10 provided above the lower base isolation foundation 20 and an upper base isolation foundation 30 provided above the base isolation device 10. The base isolation device 10 comprises a lower flange 11, a laminated rubber 12 provided above the lower flange 11 and an upper flange 13 provided above the laminated rubber 12. While one end sides of a plurality of anchor bolts 23, 33 are buried in the lower base isolation foundation 20 and the upper base isolation foundation 30, the other end sides of the anchor bolts 23, 33 are coupled to the lower flange 11 and the upper flange 13, and rod-like restraining bars 24, 34 are locked to opposite anchor bolts 23, 33 buried in the lower base isolation foundation 20 and the upper base isolation foundation 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to a seismic isolation structure including a lower seismic isolation foundation, a seismic isolation device, and an upper seismic isolation foundation, and a construction method for the seismic isolation structure.

Conventionally, there is a seismic isolation structure including a lower seismic isolation foundation, a seismic isolation device, and an upper seismic isolation foundation (see Patent Documents 1 and 2).
Patent Literature 1 discloses a seismic isolation structure including a precast concrete lower rising foundation, a seismic isolation device, and a precast concrete upper foundation. A lower base plate is embedded in the upper surface of the lower rising foundation, and a lower flange plate of the seismic isolation device is attached to the upper surface of the lower base plate. An upper base plate is embedded in the lower surface of the upper foundation, and an upper flange plate of the seismic isolation device is attached to the lower surface of the upper base plate.
Patent Literature 2 shows a seismic isolation structure including a lower foundation, a seismic isolation bearing, and a bottom plate. A plate is embedded in the upper surface of the lower foundation, and the lower flange of the seismic isolation bearing is attached to the upper surface of this plate. A plate is embedded in the lower surface of the bottom plate, and the upper flange of the seismic isolation bearing is attached to the lower surface of this plate.

Japanese Patent No. 5232106 JP 2018-115473 A

An object of the present invention is to provide a seismic isolation structure which is excellent in strength and rigidity and which can ensure high adhesion between a seismic isolation device and a seismic isolation foundation, and a construction method thereof.

A seismic isolation structure of the first invention (for example, a seismic isolation structure 1 described later) is provided on a concrete lower seismic isolation foundation (for example, a lower seismic isolation foundation 20 described later) and the lower seismic isolation foundation. a seismic isolation device (for example, a seismic isolation device 10 to be described later) and a concrete upper seismic isolation foundation (for example, an upper seismic isolation foundation 30 to be described later) provided on the seismic isolation device. The structure, the seismic isolation device includes a lower flange (for example, a lower flange 11 described later) arranged on the lower seismic isolation base, and a laminated rubber (for example, a and an upper flange (for example, an upper flange 13 described later) provided on the laminated rubber and arranged under the upper seismic isolation foundation, and the lower seismic isolation foundation and the One end side of a plurality of anchor bolts (for example, anchor bolts 23 and 33 described later) is embedded in the upper base isolation foundation, and the other end side of the anchor bolt is connected to the lower flange and the upper flange, Rod-shaped restraining muscles (for example, restraining muscles 24 and 34 to be described later) are locked to opposing anchor bolts embedded in the lower seismic isolation foundation and the upper seismic isolation foundation. and

According to this invention, one end side of a plurality of anchor bolts is embedded in the lower seismic isolation foundation and the upper seismic isolation foundation, and the other end side of the anchor bolt is connected to the lower flange and the upper flange of the seismic isolation device. In addition, restraint bars anchored by anchor bolts facing each other in plan view were embedded in the lower and upper seismic isolation foundations.
In this way, since the opposing anchor bolts are constrained by the restraining muscles, the distance between the anchor bolts is kept constant. Via, it is transmitted to the other anchor bolt and dispersed. Therefore, when an earthquake occurs, it is possible to prevent the shear stress from concentrating on a specific anchor bolt, thereby suppressing deterioration of the deformation performance of the seismic isolation structure. Therefore, by not providing a conventional base plate, it is possible to shorten the construction period.
In addition, since the lower flange of the seismic isolation device and the lower seismic isolation foundation are connected directly with anchor bolts without intervening a base plate as in the past, the lower flange of the seismic isolation device and the lower seismic isolation foundation Adhesion can be secured. In addition, since the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected directly with anchor bolts without intervening a base plate as in the conventional method, the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected to each other. Adhesion can be secured.
In addition, since the concrete of the lower base isolation foundation and the upper base isolation foundation is constrained by the anchor bolts and the restraining muscles, and a multiaxial stress state is formed, the strength and rigidity of the lower base isolation foundation and the upper base isolation foundation are increased. Therefore, without increasing the strength of the concrete that constitutes the lower base isolation foundation and the upper base isolation foundation, or increasing the size of the lower base isolation foundation and the upper base isolation foundation, the lower base isolation foundation and the upper base isolation foundation that are excellent in strength and rigidity can be obtained. A seismic isolation structure with a seismic isolation foundation can be realized.

A seismic isolation structure of the second invention (for example, a seismic isolation structure 1A described later) is provided on a concrete lower seismic isolation foundation (for example, a below-described lower seismic isolation foundation 20) and the lower seismic isolation foundation. a seismic isolation device (for example, a seismic isolation device 10 to be described later) and a concrete upper seismic isolation foundation (for example, an upper seismic isolation foundation 30 to be described later) provided on the seismic isolation device. The structure, the seismic isolation device includes a lower flange (for example, a lower flange 11 described later) arranged on the lower seismic isolation base, and a laminated rubber (for example, a and an upper flange (for example, an upper flange 13 described later) provided on the laminated rubber and arranged under the upper seismic isolation foundation, and the lower seismic isolation foundation and the One end sides of a plurality of anchor bolts are embedded in the upper base isolation foundation, and the other end sides of the anchor bolts are connected to the lower flange and the upper flange, and the lower base isolation foundation and the upper base isolation foundation are connected. All the anchor bolts embedded in are surrounded by restraint muscles (for example, restraint muscles 24A, 34A, 24B, 34B, which will be described later).

According to this invention, one end side of a plurality of anchor bolts is embedded in the lower seismic isolation foundation and the upper seismic isolation foundation, and the other end side of the anchor bolt is connected to the lower flange and the upper flange of the seismic isolation device. Furthermore, in the lower seismic isolation foundation and the upper seismic isolation foundation, restraint bars surrounding all multiple anchor bolts in plan view were embedded.
In this way, since all the anchor bolts embedded in the seismic isolation foundation are surrounded by the restraining muscles, the deformation of the anchor bolts is restrained by the restraining muscles, preventing the concentration of shear stress on specific anchor bolts when an earthquake occurs. Therefore, it is possible to suppress deterioration of the deformation performance of the seismic isolation structure. Therefore, it is possible to realize a seismic isolation structure with low cost and good workability without providing a conventional base plate.
In addition, since the lower flange of the seismic isolation device and the lower seismic isolation foundation are connected directly with anchor bolts without intervening a base plate as in the past, the lower flange of the seismic isolation device and the lower seismic isolation foundation Adhesion can be secured. In addition, since the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected directly with anchor bolts without intervening a base plate as in the conventional method, the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected to each other. Adhesion can be secured.
In addition, since the concrete of the lower base isolation foundation and the upper base isolation foundation is constrained by the anchor bolts and the restraining muscles, and a multiaxial stress state is formed, the strength and rigidity of the lower base isolation foundation and the upper base isolation foundation are increased. Therefore, without increasing the strength of the concrete that constitutes the lower base isolation foundation and the upper base isolation foundation, or increasing the size of the lower base isolation foundation and the upper base isolation foundation, the lower base isolation foundation and the upper base isolation foundation that are excellent in strength and rigidity can be obtained. A seismic isolation structure with a seismic isolation foundation can be realized.

A method for constructing a seismic isolation structure according to a third aspect of the invention is the method for constructing a seismic isolation structure described above, in which a concrete lower seismic isolation foundation is constructed on the base of the structure (for example, the lower skeleton 3 described below). A step (for example, step S1 described later), a step of installing the base isolation device on the lower base isolation foundation (for example, step S2 described below), and a concrete upper base isolation structure on the base isolation device and a step of constructing a foundation (for example, step S3 described later), and in the step of constructing the lower base isolation foundation, a side formwork (for example, a While erecting the side formwork 60), a plurality of anchor bolts and restraining muscles for restraining the anchor bolts are arranged inside the side formwork, and then concrete is placed inside the side formwork, In the step of installing the seismic isolation device, a bolt (for example, a bolt 15 to be described later) is inserted through a through hole (for example, a through hole 14 to be described later) provided in the lower flange, and is attached to the anchor bolt of the lower base isolation foundation. The lower flange of the seismic isolation device is fixed to the lower seismic isolation foundation by screwing.

According to this invention, since the deformation of the anchor bolts is restrained by the restraining muscles embedded in the seismic isolation foundation, it is possible to prevent the concentration of shear stress on specific anchor bolts in the event of an earthquake, thereby preventing the deformation of the seismic isolation structure. A decrease in performance can be suppressed. Therefore, by not providing a base plate as in the conventional case, there is no installation work of the base plate, and the construction period can be shortened.
In addition, since the lower flange of the seismic isolation device and the lower seismic isolation foundation are connected directly with anchor bolts without intervening a base plate as in the past, the lower flange of the seismic isolation device and the lower seismic isolation foundation Adhesion can be secured. In addition, since the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected directly with anchor bolts without intervening a base plate as in the conventional method, the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected to each other. Adhesion can be secured.
In addition, since the concrete of the lower base isolation foundation and the upper base isolation foundation is constrained by the anchor bolts and the restraining muscles, and a multiaxial stress state is formed, the strength and rigidity of the lower base isolation foundation and the upper base isolation foundation are increased. Therefore, without increasing the strength of the concrete that constitutes the lower base isolation foundation and the upper base isolation foundation, or increasing the size of the lower base isolation foundation and the upper base isolation foundation, the lower base isolation foundation and the upper base isolation foundation that are excellent in strength and rigidity can be obtained. A seismic isolation structure with a seismic isolation foundation can be realized.

ADVANTAGE OF THE INVENTION According to this invention, the seismic isolation structure which is excellent in intensity|strength and rigidity and can ensure the high adhesiveness of a seismic isolation apparatus and a seismic isolation foundation, and its construction method can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view of the base isolation structure which concerns on 1st Embodiment of this invention. FIG. 2 is a cross-sectional view of the seismic isolation structure of FIG. 1 taken along line II. FIG. 2 is a cross-sectional view of the seismic isolation structure of FIG. 1 taken along the line II-II. FIG. 11 is an explanatory diagram of the effect of providing a seismic isolation structure with restraining muscles (No. 1, a state in which an external force acts on a seismic isolation structure with no restraining muscles). FIG. 10 is an explanatory diagram of the effect of providing a seismic isolation structure with restraining muscles (No. 2, distribution of shear stress when an external force acts on a seismic isolation structure without restraining muscles). FIG. 10 is an explanatory diagram of the effect of providing a seismic isolation structure with restraining muscles (No. 3, distribution of shear stress when an external force acts on a seismic isolation structure provided with restraining muscles). It is a flow chart of the construction procedure of the seismic isolation structure. Explanatory diagram of the construction procedure of the seismic isolation structure (Part 1, construction status of the lower seismic isolation foundation) Explanatory diagram of the construction procedure of the seismic isolation structure (Part 2, installation status of the seismic isolation device) It is a vertical cross-sectional view of the seismic isolation structure which concerns on 2nd Embodiment of this invention. FIG. 11 is a cross-sectional view of the seismic isolation structure of FIG. 10 taken along line III-III. It is a vertical cross-sectional view of the seismic isolation structure which concerns on 3rd Embodiment of this invention. FIG. 13 is a sectional view of the seismic isolation structure of FIG. 12 taken along line IV-IV.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In the following description of the embodiments, the same components are denoted by the same reference numerals, and the description thereof will be omitted or simplified.
[First Embodiment]
FIG. 1 is a longitudinal sectional view of a seismic isolation structure 1 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the seismic isolation structure 1 of FIG. 1 taken along the line II. FIG. 3 is a II-II sectional view of the seismic isolation structure 1 of FIG. In FIG. 1, the reinforcing bars 21 and 31 are omitted for easy understanding.

The seismic isolation structure 1 includes a reinforced concrete lower seismic isolation foundation 20 built on a lower skeleton 3 as the foundation of a building foundation 2, a seismic isolation device 10 provided on the lower seismic isolation foundation 20, and an isolation system. An upper seismic isolation foundation 30 made of reinforced concrete is provided on the seismic device 10 and supports the upper skeleton 4 of the foundation 2 of the building. The seismic isolation device 10 is supported by the lower skeleton 3 (lower seismic isolation foundation 20) and seismically isolates the upper skeleton 4 (upper seismic isolation foundation 30).

The lower seismic isolation foundation 20 includes cage-shaped reinforcing bars 21 arranged along the side surface and upper surface, and a concrete body 22 in which the cage-shaped reinforcing bars 21 are embedded.
Further, a plurality of anchor bolts 23 are embedded in the lower seismic isolation foundation 20 and are arranged in a circular ring in plan view, and the anchor bolts 23 facing each other among the plurality of anchor bolts 23 in plan view are locked. The streaks 24 are embedded vertically in two stages. That is, the lower seismic isolation foundation 20 is not provided with a conventional base plate.
The restraint bar 24 is a bar-shaped reinforcing bar, and both ends thereof are bent 135° to form hooks 25 . Hooks 25 at both ends of the restraining muscle 24 are locked to anchor bolts 23 .
The anchor bolt 23 includes a long nut 50 and a projecting bolt 51 screwed onto the lower end side of the long nut 50 . The upper end surface of the long nut 50 is flush with the upper surface of the lower seismic isolation foundation 20 .

The upper seismic isolation foundation 30 has the same configuration as the lower seismic isolation foundation 20 . That is, the upper seismic isolation foundation 30 includes cage-shaped reinforcing bars 31 arranged along the side surface and upper surface, and a concrete body 32 in which the cage-shaped reinforcing bars 31 are embedded.
Furthermore, a plurality of anchor bolts 33 are embedded in the upper seismic isolation foundation 30 and are arranged in a circular ring in plan view, and the anchor bolts 33 facing each other among the plurality of anchor bolts 33 in plan view are locked. The stripes 34 are embedded vertically in two stages. That is, the upper seismic isolation foundation 30 is not provided with a conventional base plate.
The restraining bar 34 is a bar-shaped reinforcing bar, and both ends thereof are bent 135° to form hooks 35 . Hooks 35 at both ends of the restraining muscle 34 are locked to anchor bolts 33 .
The anchor bolt 33 includes a long nut 50 and a projecting bolt 51 screwed onto the upper end side of the long nut 50 . The lower end surface of the long nut 50 is flush with the lower surface of the upper seismic isolation base 30 .

The seismic isolation device 10 includes a lower flange 11 , a laminated rubber 12 provided on the lower flange 11 , and an upper flange 13 provided on the laminated rubber 12 .
The laminated rubber 12 is formed by alternately laminating rubber and steel plates, and is elastically deformable.
A plurality of through holes 14 are formed in the lower flange 11 so as to be arranged in an annular shape. A bolt 15 is inserted through the through hole 14 and screwed to the upper end of an anchor bolt 23 of the lower seismic isolation foundation 20 . Thereby, the seismic isolation device 10 is fixed to the lower seismic isolation foundation 20 .
A plurality of through holes 16 are formed in the upper flange 13 so as to be arranged in an annular shape. A bolt 17 is inserted through the through hole 16 and screwed to the lower end of an anchor bolt 33 of the upper seismic isolation base 30 . Thereby, the seismic isolation device 10 is fixed to the upper seismic isolation foundation 30 .

The effect of providing the restraint bars in the seismic isolation structure will be described below.
If the seismic isolation structure is not provided with a base plate and restraint bars, the following problems arise. That is, as shown in FIG. 4, when a horizontal force P acts on the seismic isolation structure during an earthquake, the shear force is borne entirely by the anchor bolts. Then, the distribution of the shear stress of the anchor bolts of the lower seismic isolation foundation 20 becomes as shown in FIG. In other words, there is a risk that a large shear stress (stress concentration) will occur in the anchor bolt located on the opposite side of the direction in which the horizontal force P is applied, and a cone-shaped failure (lateral cone-shaped failure) will occur on the side surface of the lower seismic isolation foundation 20. There is
Therefore, in the present invention, even if a base plate is not provided, by providing a restraint muscle that constrains the anchor bolts at positions facing each other, as shown in FIG. 6, the shear force acting on the anchor bolts is dispersed. , to prevent lateral cone failure.

The construction procedure of the seismic isolation structure 1 will be described below with reference to the flowchart of FIG.
In step S1, a lower seismic isolation foundation 20 is constructed on the lower skeleton 3 of the foundation 2 of the building. Specifically, as shown in FIG. 8, a side formwork 60 is erected on the side of the lower seismic isolation foundation 20, and anchor bolts 23 and restraint bars 24 are arranged inside the side formwork 60, After that, concrete is placed inside the side formwork 60 .
In step S2, the seismic isolation device 10 is installed on the lower seismic isolation foundation 20, as shown in FIG. Specifically, the seismic isolation device 10 is placed on the lower seismic isolation foundation 20, the bolts 15 are inserted through the through holes 14 of the lower flange 11 of the seismic isolation device 10, and the anchor bolts of the lower seismic isolation foundation 20 are inserted. The seismic isolation device 10 is fixed to the lower seismic isolation foundation 20 by screwing it to 23 .
In step S3, an upper seismic isolation foundation 30 is constructed above the seismic isolation device 10 and below the upper frame 4. As shown in FIG. Specifically, the anchor bolts 33 are attached to the seismic isolation device 10 by inserting the bolts 17 through the through holes 16 of the upper flange 13 of the seismic isolation device 10 and screwing the anchor bolts 33 . Next, the restraining bars 34 are arranged, and then a formwork is erected at the bottom and side surfaces of the upper seismic isolation foundation 30, and concrete is poured into the formwork.

According to this embodiment, there are the following effects.
(1) One end side of a plurality of anchor bolts 23, 33 is embedded in the lower base isolation foundation 20 and the upper base isolation foundation 30, and the other end side of the anchor bolts 23, 33 is embedded in the lower flange 11 and the upper base isolation device 10. It was connected to the flange 13 . Further, in the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30, restraint bars 24, 34 with hooks 25, 35 at both ends engaged with anchor bolts 23, 33 facing each other in a plan view are embedded.
In this way, since the anchor bolts 23, 33 facing each other are constrained by the restraining muscles 24, 34 with hooks, the distance between the anchor bolts 23, 33 is kept constant. , 33 is transmitted through the restraining muscles 24, 34 to the other anchor bolt 23, 33 and dispersed. Therefore, when an earthquake occurs, concentration of shear stress on specific anchor bolts 23 and 33 can be prevented, and degradation of deformation performance of the seismic isolation structure 1 can be suppressed. Therefore, by not providing a base plate as in the conventional case, there is no installation work of the base plate, and the construction period can be shortened.

(2) Since the lower flange 11 of the seismic isolation device 10 and the lower base isolation foundation 20 are directly connected by the anchor bolts 23 without interposing a base plate as in the conventional art, the lower flange 11 of the seismic isolation device 10 and High adhesion to the lower seismic isolation foundation 20 can be ensured. In addition, since the upper flange 13 of the seismic isolation device 10 and the upper base isolation base 30 are directly connected by the anchor bolts 33 without interposing a base plate as in the conventional art, the upper flange 13 and the upper part of the seismic isolation device 10 High adhesion to the seismic isolation foundation 30 can be ensured.
(3) The concrete of the lower base isolation foundation 20 and the upper base isolation foundation 30 is constrained by the anchor bolts 23, 33 and the restraining muscles 24, 34, and a multiaxial stress state is formed. The strength and stiffness of the seismic foundation 30 are increased. Therefore, the lower base isolation structure having excellent strength and rigidity can be obtained without increasing the strength of the concrete constituting the lower base isolation base 20 and the upper base isolation base 30 or increasing the size of the lower base isolation base 20 and the upper base isolation base 30 . A seismic isolation structure 1 having a seismic foundation 20 and an upper seismic isolation foundation 30 can be realized.

[Second embodiment]
FIG. 10 is a longitudinal sectional view of a seismic isolation structure 1A according to the second embodiment of the present invention. 11 is a cross-sectional view of the seismic isolation structure 1A of FIG. 10 taken along line III-III. In FIG. 10, the reinforcing bars 21 and 31 are omitted for easy understanding.
In this embodiment, the shapes of the restraining muscles 24A of the lower seismic isolation foundation 20 and the restraining muscles 34A of the upper seismic isolation foundation 30 are different from those of the first embodiment. In other words, the restraining muscles 24A, 34A have an annular shape surrounding all of the plurality of anchor bolts 23, 33 in a plan view, and are provided in two stages vertically.
According to this embodiment, the same effects as (1) to (3) described above are obtained.

[Third embodiment]
FIG. 12 is a longitudinal sectional view of a seismic isolation structure 1B according to the third embodiment of the invention. FIG. 13 is a IV-IV cross-sectional view of the seismic isolation structure 1B of FIG. In FIG. 12, the reinforcing bars 21 and 31 are omitted for easy understanding.
In this embodiment, the shapes of the restraining muscles 24B of the lower seismic isolation foundation 20 and the restraining muscles 34B of the upper seismic isolation foundation 30 are different from those of the first embodiment. That is, the restraining muscles 24B, 34B are annular spiral muscles surrounding all of the plurality of anchor bolts 23, 33 in plan view.
According to this embodiment, the same effects as (1) to (3) described above are obtained.

It should be noted that the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.

DESCRIPTION OF SYMBOLS 1, 1A, 1B... Seismic isolation structure 2... Foundation 3... Lower skeleton (foundation) 4... Upper skeleton 10... Seismic isolation device 11... Lower flange 12... Laminated rubber 13... Upper flange 14... Through hole 15... Bolt 16... Penetration Hole 17... Bolt 20... Lower base isolation foundation 21... Reinforcement bar 22... Concrete body 23... Anchor bolt 24, 24A, 24B... Restraint bar 25... Hook 30... Upper base isolation foundation 31... Reinforcement bar 32... Concrete body 33... Anchor bolt 34 , 34A, 34B... Restrictive bar 35... Hook 50... Long nut 51... Bolt with projection 60... Side formwork

Claims (3)

A seismic isolation structure including a concrete lower seismic isolation foundation, a seismic isolation device provided on the lower seismic isolation foundation, and a concrete upper seismic isolation foundation provided on the seismic isolation device There is
The base isolation device includes a lower flange arranged on the lower base isolation foundation, a laminated rubber provided on the lower flange, and a base isolation device provided on the laminated rubber under the upper base isolation foundation. an upper flange positioned on the
One end sides of a plurality of anchor bolts are embedded in the lower base isolation foundation and the upper base isolation foundation, and the other end sides of the anchor bolts are connected to the lower flange and the upper flange,
A seismic isolation structure, wherein rod-shaped restraint muscles are engaged with opposing anchor bolts embedded in the lower seismic isolation foundation and the upper seismic isolation foundation. A seismic isolation structure including a concrete lower seismic isolation foundation, a seismic isolation device provided on the lower seismic isolation foundation, and a concrete upper seismic isolation foundation provided on the seismic isolation device. and
The base isolation device includes a lower flange arranged on the lower base isolation foundation, a laminated rubber provided on the lower flange, and a base isolation device provided on the laminated rubber under the upper base isolation foundation. an upper flange positioned on the
One end sides of a plurality of anchor bolts are embedded in the lower base isolation foundation and the upper base isolation foundation, and the other end sides of the anchor bolts are connected to the lower flange and the upper flange,
A seismic isolation structure, wherein all the anchor bolts embedded in the lower seismic isolation foundation and the upper seismic isolation foundation are surrounded by restraint muscles. A method for constructing a seismic isolation structure according to claim 1 or 2,
A step of constructing a concrete lower seismic isolation foundation on the foundation of the structure;
installing the seismic isolation device on the lower seismic isolation foundation;
and building a concrete upper seismic isolation foundation on the seismic isolation device,
In the step of constructing the lower seismic isolation foundation, a side formwork is erected at a position to be a side surface of the lower seismic isolation foundation, and a plurality of anchor bolts and restraining muscles that constrain the anchor bolts are placed inside the side formwork. is placed, then concrete is placed inside the side formwork,
In the step of installing the seismic isolation device, a bolt is inserted through a through hole provided in the lower flange and screwed into the anchor bolt of the lower base isolation foundation, thereby moving the lower flange of the seismic isolation device to the lower portion. A method for constructing a seismic isolation structure characterized by fixing to a seismic isolation foundation.

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