Seismic isolation structure and construction method thereof

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

[Technical Field]

[0001] 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 method for constructing the seismic isolation structure. [Background technology]

[0002] Conventionally, there are seismic isolation structures that include a lower seismic isolation foundation, a seismic isolation device, and an upper seismic isolation foundation (see Patent Documents 1 and 2). Patent Document 1 shows a seismic isolation structure comprising 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 this 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 this upper base plate. Patent Document 2 shows a seismic isolation structure comprising a lower foundation, a seismic isolation bearing, and a bottom plate. A plate is embedded in the upper surface of the lower foundation, and a 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 an upper flange of the seismic isolation bearing is attached to the lower surface of this plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5232106 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-115473 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a seismic isolation structure that is excellent in strength and rigidity and can ensure high adhesion between the seismic isolation device and the seismic isolation foundation, and a method for constructing the same. [Means for solving the problem]

[0005] A seismic isolation structure of a first invention (for example, a seismic isolation structure 1 described later) is a seismic isolation structure including a lower seismic isolation foundation made of concrete (for example, a lower seismic isolation foundation 20 described later), a seismic isolation device (for example, a seismic isolation device 10 described later) provided on the lower seismic isolation foundation, and an upper seismic isolation foundation made of concrete (for example, an upper seismic isolation foundation 30 described later) provided on the seismic isolation device, and the seismic isolation device includes a lower flange (for example, a lower flange 11 described later) arranged on the lower seismic isolation foundation, laminated rubber (for example, laminated rubber 12 described later) provided on the lower flange, and a laminated rubber and an upper flange (for example, upper flange 13 described later) provided on the base and positioned below the upper seismic isolation foundation, one ends of a plurality of anchor bolts (for example, anchor bolts 23 and 33 described later) are embedded in the lower seismic isolation foundation and the upper seismic isolation foundation, and the other ends of the anchor bolts are connected to the lower flange and the upper flange, and rod-shaped restraining bars (for example, restraining bars 24 and 34 described later) are engaged with opposing ones of the anchor bolts embedded in the lower seismic isolation foundation and the upper seismic isolation foundation.

[0006] According to this invention, one end of a plurality of anchor bolts is embedded in the lower isolation foundation and the upper isolation foundation, and the other end of the anchor bolts is connected to the lower flange and the upper flange of the seismic isolation device. Furthermore, restraining reinforcement is embedded in the lower isolation foundation and the upper isolation foundation, and is engaged with the anchor bolts that face each other in a plan view. In this way, opposing anchor bolts are restrained by restraining bars, ensuring a constant distance between the anchor bolts. This means that shear stress generated in one of the opposing anchor bolts is transmitted to the other anchor bolt via the restraining bars and dispersed. This prevents shear stress from concentrating on a specific anchor bolt during an earthquake, suppressing a decline in the deformation capacity of the seismic isolation structure. Therefore, by not using a base plate as in the past, construction time 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 the need for a base plate as in the past, it is possible to ensure high adhesion between the lower flange of the seismic isolation device and the lower seismic isolation foundation.In addition, since the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected directly with anchor bolts, without the need for a base plate as in the past, it is possible to ensure high adhesion between the upper flange of the seismic isolation device and the upper seismic isolation foundation. Furthermore, the anchor bolts and restraining reinforcement constrain the concrete of the lower and upper seismic isolation foundations, creating a multiaxial stress state, which increases the strength and rigidity of the lower and upper seismic isolation foundations. This makes it possible to achieve a seismic isolation structure equipped with lower and upper seismic isolation foundations that are excellent in strength and rigidity, without having to increase the strength of the concrete that makes up the lower and upper seismic isolation foundations or increase the size of the lower and upper seismic isolation foundations.

[0007] A seismic isolation structure of the second invention (for example, a seismic isolation structure 1A described later) is a seismic isolation structure including a lower seismic isolation foundation made of concrete (for example, a lower seismic isolation foundation 20 described later), a seismic isolation device (for example, a seismic isolation device 10 described later) provided on the lower seismic isolation foundation, and an upper seismic isolation foundation made of concrete (for example, an upper seismic isolation foundation 30 described later) provided on the seismic isolation device, and the seismic isolation device includes a lower flange (for example, a lower flange 11 described later) arranged on the lower seismic isolation foundation, and a laminated rubber (for example, a laminated rubber and an upper flange (for example, upper flange 13 described later) that is provided on the laminated rubber and placed below the upper seismic isolation foundation, wherein one ends of a plurality of anchor bolts are embedded in the lower seismic isolation foundation and the upper seismic isolation foundation, and the other ends of the anchor bolts are connected to the lower flange and the upper flange, and all of the anchor bolts embedded in the lower seismic isolation foundation and the upper seismic isolation foundation are surrounded by restraining bars (for example, restraining bars 24A, 34A, 24B, 34B described later).

[0008] According to this invention, one end of a plurality of anchor bolts is embedded in the lower isolation foundation and the upper isolation foundation, and the other end of the anchor bolts is connected to the lower flange and the upper flange of the seismic isolation device. Furthermore, restraining reinforcement is embedded in the lower isolation foundation and the upper isolation foundation so as to surround all of the plurality of anchor bolts in a plan view. In this way, all anchor bolts embedded in the seismic isolation foundation are surrounded by restraining reinforcement, which restrains the deformation of the anchor bolts and prevents shear stress from concentrating on specific anchor bolts during an earthquake, thereby suppressing a decline in the deformation performance of the seismic isolation structure.As a result, a low-cost, easy-to-construct seismic isolation structure can be realized without using a base plate as in the past. In addition, since the lower flange of the seismic isolation device and the lower seismic isolation foundation are connected directly with anchor bolts, without the need for a base plate as in the past, it is possible to ensure high adhesion between the lower flange of the seismic isolation device and the lower seismic isolation foundation.In addition, since the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected directly with anchor bolts, without the need for a base plate as in the past, it is possible to ensure high adhesion between the upper flange of the seismic isolation device and the upper seismic isolation foundation. Furthermore, the anchor bolts and restraining reinforcement constrain the concrete of the lower and upper seismic isolation foundations, creating a multiaxial stress state, which increases the strength and rigidity of the lower and upper seismic isolation foundations. This makes it possible to achieve a seismic isolation structure equipped with lower and upper seismic isolation foundations that are excellent in strength and rigidity, without having to increase the strength of the concrete that makes up the lower and upper seismic isolation foundations or increase the size of the lower and upper seismic isolation foundations.

[0009] The method for constructing a seismic isolation structure of the third invention is the method for constructing the seismic isolation structure described above, and includes the steps of constructing a lower seismic isolation foundation made of concrete on a base of a structure (for example, a lower structure 3 described later) (for example, step S1 described later), installing the seismic isolation device on the lower seismic isolation foundation (for example, step S2 described later), and constructing an upper seismic isolation foundation made of concrete on the seismic isolation device (for example, step S3 described later). In the step of constructing the lower seismic isolation foundation, The process involves erecting a side formwork (for example, side formwork 60 described below) and placing multiple anchor bolts and restraining bars that restrain the anchor bolts inside the side formwork, then pouring concrete inside the side formwork, and installing the seismic isolation device.The process is characterized in that a bolt (for example, bolt 15 described below) is inserted into a through hole (for example, through hole 14 described below) provided in the lower flange and screwed into the anchor bolt of the lower seismic isolation foundation, thereby fixing the lower flange of the seismic isolation device to the lower seismic isolation foundation.

[0010] According to this invention, the anchor bolt deformation is restrained by the restraining bars embedded in the seismic isolation foundation, which prevents shear stress from concentrating on specific anchor bolts during an earthquake and suppresses a decrease in the deformation performance of the seismic isolation structure. Therefore, by not providing a base plate as in the past, there is no need to install a base plate, and construction time 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 the need for a base plate as in the past, it is possible to ensure high adhesion between the lower flange of the seismic isolation device and the lower seismic isolation foundation.In addition, since the upper flange of the seismic isolation device and the upper seismic isolation foundation are connected directly with anchor bolts, without the need for a base plate as in the past, it is possible to ensure high adhesion between the upper flange of the seismic isolation device and the upper seismic isolation foundation. Furthermore, the anchor bolts and restraining reinforcement constrain the concrete of the lower and upper seismic isolation foundations, creating a multiaxial stress state, which increases the strength and rigidity of the lower and upper seismic isolation foundations. This makes it possible to achieve a seismic isolation structure equipped with lower and upper seismic isolation foundations that are excellent in strength and rigidity, without having to increase the strength of the concrete that makes up the lower and upper seismic isolation foundations or increase the size of the lower and upper seismic isolation foundations. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a seismic isolation structure that is excellent in strength and rigidity and that can ensure high adhesion between the seismic isolation device and the seismic isolation foundation, and a method for constructing the same. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a vertical cross-sectional view of a seismic isolation structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the seismic isolation structure of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view of the seismic isolation structure of FIG. 1 taken along line II-II. [Figure 4] This is an explanatory diagram of the effect of installing restraint reinforcement in a seismic isolation structure (Part 1: A state in which an external force acts on a seismic isolation structure without restraint reinforcement). [Figure 5] This is an explanatory diagram of the effect of installing restraint reinforcement in a seismic isolation structure (Part 2: Distribution of shear stress when an external force acts on a seismic isolation structure without restraint reinforcement). [Figure 6] This is an explanatory diagram of the effect of installing restraining bars in a seismic isolation structure (Part 3: Distribution of shear stress when an external force acts on a seismic isolation structure with restraining bars). [Figure 7] 1 is a flowchart of the construction procedure for a seismic isolation structure. [Figure 8] Diagram of the construction procedure for the seismic isolation structure (Part 1, construction status of the lower seismic isolation foundation) [Figure 9] Diagram of the construction procedure for a seismic isolation structure (Part 2, installation of seismic isolation devices) [Figure 10]1 is a vertical cross-sectional view of a seismic isolation structure according to a first embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view of the seismic isolation structure of FIG. 10 taken along line III-III. [Figure 12] FIG. 10 is a vertical cross-sectional view of a seismic isolation structure according to a second embodiment of the present invention. [Figure 13] 13 is a cross-sectional view of the seismic isolation structure of FIG. 12 taken along line IV-IV. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following describes embodiments of the present invention. and reference examples The following embodiments will be described with reference to the accompanying drawings. and reference examples In the description, the same components are denoted by the same reference numerals, and the description thereof will be omitted or simplified. 〔fruit Form〕 FIG. 1 shows the structure of the present invention. one Fig. 2 is a longitudinal cross-sectional view of the seismic isolation structure 1 according to the embodiment. Fig. 2 is a cross-sectional view taken along line II of the seismic isolation structure 1 of Fig. 1. Fig. 3 is a cross-sectional view taken along line II-II of the seismic isolation structure 1 of Fig. 1. In Fig. 1, reinforcing bars 21 and 31 are omitted for ease of understanding.

[0014] The seismic isolation structure 1 comprises a lower seismic isolation foundation 20 made of reinforced concrete constructed on a lower skeleton 3 that serves as the base for a building foundation 2, a seismic isolation device 10 provided on the lower seismic isolation foundation 20, and an upper seismic isolation foundation 30 made of reinforced concrete that is provided on the seismic isolation device 10 and supports an upper skeleton 4 of the building foundation 2. The seismic isolation device 10 is supported by the lower skeleton 3 (lower seismic isolation foundation 20) and provides seismic isolation for the upper skeleton 4 (upper seismic isolation foundation 30).

[0015] The lower seismic isolation foundation 20 comprises cage-shaped reinforcing bars 21 arranged along the side and top surfaces, and a concrete body 22 in which the cage-shaped reinforcing bars 21 are embedded. Furthermore, a plurality of anchor bolts 23 are buried in the lower seismic isolation foundation 20 and are arranged in a circular pattern in plan view, and restraining bars 24 are buried in two levels, one above the other, that engage with opposing ones of the plurality of anchor bolts 23 in plan view. In other words, the lower seismic isolation foundation 20 does not have a base plate as in the conventional case. The restraining bars 24 are rod-shaped reinforcing bars, both ends of which are bent at 135° to form hooks 25. The hooks 25 at both ends of the restraining bars 24 are engaged with the anchor bolts 23. The anchor bolt 23 includes a long nut 50 and a protruding bolt 51 that is 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 base 20.

[0016] 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 and top surfaces, and a concrete body 32 in which the cage-shaped reinforcing bars 31 are embedded. Furthermore, a plurality of anchor bolts 33 are buried in the upper seismic isolation foundation 30 and are arranged in a circular ring shape in plan view, and restraining bars 34 are buried in two levels, one above the other, that engage with opposing ones of the plurality of anchor bolts 33 in plan view. In other words, the upper seismic isolation foundation 30 does not have a base plate as in the past. The restraining bars 34 are rod-shaped reinforcing bars, both ends of which are bent 135° to form hooks 35. The hooks 35 at both ends of the restraining bars 34 are engaged with the anchor bolts 33. The anchor bolt 33 includes a long nut 50 and a protruding 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.

[0017] 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 made by alternately laminating rubber and steel plates, and is elastically deformable. A plurality of through holes 14 are formed in the lower flange 11 and arranged in a circular ring shape. Bolts 15 are inserted into these through holes 14 and are screwed onto the upper ends of anchor bolts 23 of the lower seismic isolation base 20. In this way, the seismic isolation device 10 is fixed to the lower seismic isolation base 20. A plurality of through holes 16 are formed in the upper flange 13 and arranged in a circular ring shape. Bolts 17 are inserted into these through holes 16 and are screwed onto the lower ends of anchor bolts 33 of the upper seismic isolation foundation 30. In this way, the seismic isolation device 10 is fixed to the upper seismic isolation foundation 30.

[0018] Below, we will explain the effects of providing restraining reinforcement in a seismic isolation structure. If a base isolation structure is not provided with a base plate and no restraining reinforcement is also provided, the following problem occurs. Specifically, as shown in Figure 4, when horizontal force P acts on the base isolation structure during an earthquake, the anchor bolts will bear all of the shear force. This results in the distribution of shear stress in the anchor bolts of the lower base isolation foundation 20 being as shown in Figure 5. In other words, large shear stress is generated in the anchor bolts located on the opposite side of the direction in which horizontal force P is applied (stress concentration), which may cause cone-shaped failure (lateral cone-shaped failure) on the side of the lower base isolation foundation 20. Therefore, in the present invention, even if a base plate is not provided, by providing restraining bars that restrain the anchor bolts that are located in opposing positions, the shear force acting on the anchor bolts is dispersed and side cone-shaped failure is prevented, as shown in Figure 6.

[0019] The construction procedure for the seismic isolation structure 1 will be described below with reference to the flowchart of FIG. In step S1, the lower seismic isolation foundation 20 is constructed on the lower skeleton 3 of the building foundation 2. Specifically, as shown in Fig. 8, side formwork 60 is erected at a position that will become the side of the lower seismic isolation foundation 20, and anchor bolts 23 and restraining reinforcement 24 are placed inside the side formwork 60. After that, concrete is poured inside the side formwork 60. In step S2, as shown in Fig. 9, the seismic isolation device 10 is installed on the lower seismic isolation foundation 20. Specifically, the seismic isolation device 10 is placed on the lower seismic isolation foundation 20, and bolts 15 are inserted into the through holes 14 of the lower flange 11 of the seismic isolation device 10 and screwed into the anchor bolts 23 of the lower seismic isolation foundation 20, thereby fixing the seismic isolation device 10 to the lower seismic isolation foundation 20. In step S3, the upper seismic isolation foundation 30 is constructed above the seismic isolation device 10 and below the upper frame 4. Specifically, bolts 17 are inserted into the through holes 16 in the upper flange 13 of the seismic isolation device 10 and screwed into the anchor bolts 33, thereby attaching the anchor bolts 33 to the seismic isolation device 10. Next, restraining reinforcement 34 is arranged, and then formwork is erected at positions that will become the bottom and side surfaces of the upper seismic isolation foundation 30, and concrete is poured into the formwork.

[0020] According to this embodiment, the following effects are obtained. (1) One end of a plurality of anchor bolts 23, 33 was embedded in the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30, and the other end of the anchor bolts 23, 33 was connected to the lower flange 11 and the upper flange 13 of the seismic isolation device 10. Furthermore, restraining bars 24, 34 with hooks 25, 35 at both ends engaged with the anchor bolts 23, 33 that face each other in a plan view were embedded in the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30. In this way, the opposing anchor bolts 23, 33 are restrained by the hooked restraining bars 24, 34, and a constant distance between the anchor bolts 23, 33 is maintained, so that shear stress generated in one of the two opposing anchor bolts 23, 33 is transmitted to and dispersed by the restraining bars 24, 34 to the other anchor bolt 23, 33. This prevents shear stress from concentrating on a specific anchor bolt 23, 33 in the event of an earthquake, and suppresses a decrease in the deformation performance of the seismic isolation structure 1. Therefore, by not providing a base plate as in the past, there is no need for base plate installation work, and construction time can be shortened.

[0021] (2) The lower flange 11 of the seismic isolation device 10 and the lower seismic isolation foundation 20 are connected directly with anchor bolts 23, without the need for a base plate as in the conventional case, thereby ensuring high adhesion between the lower flange 11 of the seismic isolation device 10 and the lower seismic isolation foundation 20. In addition, the upper flange 13 of the seismic isolation device 10 and the upper seismic isolation foundation 30 are connected directly with anchor bolts 33, without the need for a base plate as in the conventional case, thereby ensuring high adhesion between the upper flange 13 of the seismic isolation device 10 and the upper seismic isolation foundation 30. (3) The anchor bolts 23, 33 and the restraining reinforcement bars 24, 34 restrain the concrete of the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30, forming a multiaxial stress state, thereby increasing the strength and rigidity of the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30. Therefore, it is possible to realize a seismic isolation structure 1 equipped with a lower seismic isolation foundation 20 and an upper seismic isolation foundation 30 that are excellent in strength and rigidity, without increasing the strength of the concrete that makes up the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30 or increasing the size of the lower seismic isolation foundation 20 and the upper seismic isolation foundation 30.

[0022] [ First reference example 〕 FIG. 10 shows the method of the present invention. First reference example Fig. 11 is a vertical cross-sectional view of the base isolation structure 1A according to Fig. 10. Fig. 11 is a cross-sectional view of the base isolation structure 1A taken along line III-III in Fig. 10. In Fig. 10, the reinforcing bars 21 and 31 are omitted for ease of understanding. Book Reference example In this embodiment, the shapes of the restraining bars 24A of the lower seismic isolation foundation 20 and the restraining bars 34A of the upper seismic isolation foundation 30 are different from those in the first embodiment. That is, the restraining bars 24A, 34A are annular in shape in plan view that surround all of the multiple anchor bolts 23, 33, and are provided in two rows, one above the other. Book Reference example According to the method, the same effects as those of (1) to (3) above can be obtained.

[0023] [ Second reference example 〕 FIG. 12 shows the Second reference exampleFig. 13 is a vertical cross-sectional view of the base isolation structure 1B according to Fig. 12. Fig. 13 is a cross-sectional view of the base isolation structure 1B taken along line IV-IV in Fig. 12. In Fig. 12, the reinforcing bars 21 and 31 are omitted for ease of understanding. Book Reference example In this embodiment, the shapes of the constraining bars 24B of the lower seismic isolation foundation 20 and the constraining bars 34B of the upper seismic isolation foundation 30 are different from those in the first embodiment. That is, the constraining bars 24B, 34B are annular spiral bars that surround all of the multiple anchor bolts 23, 33 in plan view. Book Reference example According to the method, the same effects as those of (1) to (3) above can be obtained.

[0024] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Explanation of symbols]

[0025] 1, 1A, 1B...Seismic isolation structure 2...Foundation 3...Lower structure (base) 4...Upper structure 10...Seismic isolation device 11...Lower flange 12...Laminated rubber 13...Upper flange 14...Through hole 15...Bolt 16...Through hole 17...Bolt 20... Lower seismic isolation foundation 21... Steel bars 22... Concrete body 23...Anchor bolt 24, 24A, 24B...Restraining bar 25...Hook 30...Upper seismic isolation foundation 31...Reinforced concrete 32...Concrete body 33...Anchor bolt 34, 34A, 34B...Restraining bar 35...Hook 50...Long nut 51...Protruding bolt 60...Side formwork

Claims

1. A seismic isolation structure including a lower seismic isolation foundation made of concrete, a seismic isolation device provided on the lower seismic isolation foundation, and an upper seismic isolation foundation made of concrete provided on the seismic isolation device, The seismic isolation device includes a lower flange disposed on the lower seismic isolation foundation, a laminated rubber provided on the lower flange, and an upper flange provided on the laminated rubber and disposed below the upper seismic isolation foundation, At least one of a surface of the lower seismic isolation foundation that abuts against the lower flange and a surface of the upper seismic isolation foundation that abuts against the upper flange is a concrete surface, One end sides of a plurality of anchor bolts are embedded in the lower seismic isolation foundation and the upper seismic isolation foundation, and the other end sides of the anchor bolts are connected to the lower flange and the upper flange, The anchor bolts are arranged in a circular ring shape in a plan view, A seismic isolation structure characterized in that all of the opposing anchor bolts are connected to each other by rod-shaped restraining bars.

2. A method for constructing a seismic isolation structure according to claim 1, constructing a concrete lower seismic isolation foundation on the base of the structure; a step of installing the seismic isolation device on the lower seismic isolation foundation; and constructing a concrete upper seismic isolation foundation on the seismic isolation device, In the process of constructing the lower seismic isolation foundation, side forms are erected at positions that will become the sides of the lower seismic isolation foundation, and a plurality of anchor bolts and restraining bars that restrain the anchor bolts are placed inside the side forms, and then concrete is poured inside the side forms, A method for constructing a seismic isolation structure, characterized in that in the process of installing the seismic isolation device, a bolt is inserted into a through hole provided in the lower flange and screwed into the anchor bolt of the lower seismic isolation foundation, thereby fixing the lower flange of the seismic isolation device to the lower seismic isolation foundation.

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