Seismic isolation foundations and their construction methods

Abstract

To provide a seismic isolation foundation and its construction method that eliminates the need for expensive base plates and the time-consuming work of ensuring flatness on the top surface of the foundation concrete, while allowing the vertical load acting from the seismic isolation device to act as evenly as possible on the area on the top surface of the foundation concrete where the seismic isolation device is placed, thereby suppressing the occurrence of stress concentration points. [Solution] The seismic isolation foundation 100 on which the seismic isolation device 200 is attached comprises a foundation concrete 30 and an unevenness adjustment material 40 provided in the area on the top surface 31 of the foundation concrete 30 where the seismic isolation device 200 is placed.

Description

Technical Field

[0001] The present invention relates to a seismic isolation foundation and a construction method thereof.

Background Art

[0002] A seismic isolation foundation that supports various forms of seismic isolation devices such as laminated rubber devices and sliding devices generally has a configuration in which a base plate is embedded at the top end of columnar or rectangular parallelepiped foundation concrete. The base plate is provided with filling holes for filling concrete inside the formwork below it and bolt holes for bolt-joining the lower plate of the seismic isolation device. Further, anchor bolts for embedding in the constructed foundation concrete are attached to its lower surface. The anchor bolts are members that transmit these external forces to the foundation concrete while resisting the pulling force and shear force acting through the seismic isolation device.

[0003] When the flatness of the top end of the foundation concrete to be constructed (manufactured) is not good, the weight (vertical load) of the superstructure acting from the seismic isolation device does not act evenly over the entire area of the foundation concrete. Therefore, the above configuration in which a base plate with a flat surface is provided at the top end of the seismic isolation device is generally adopted, and the seismic isolation device is attached to the surface of the base plate. The size of one side or the diameter of a base plate that is square or circular in plan view generally ranges from about 1 m to 2 m, for example.

[0004] However, the manufacturing cost of a base plate with high flatness and a large planar area is generally high, leading to an increase in construction cost. Therefore, a method of performing minor shaving or piling to eliminate the base plate and ensure the flatness of the top end surface of the foundation concrete is considered. However, this method requires a great deal of labor and time for these shaving and piling operations, and this problem becomes even more prominent at sites with a large number of seismic isolation foundations.

[0005] Therefore, a seismic isolation foundation and its construction method are desirable that eliminate the need for expensive base plates and the time-consuming work of ensuring flatness on the top surface of the foundation concrete, while simultaneously distributing the vertical load acting from the seismic isolation device as evenly as possible across the area on the top surface of the foundation concrete where the seismic isolation device is placed, thereby suppressing the occurrence of stress concentration points.

[0006] Here, Patent Document 1 proposes a seismic isolation foundation forming device. This device comprises a formwork plate positioned on the circumferential surface of the concrete that will be poured to form the seismic isolation foundation that will receive the seismic isolation device, a base plate positioned on the upper surface of the seismic isolation foundation, and a lid positioned around the base plate. An injection port for pouring concrete is formed in at least one of the areas of the base plate excluding the installation area when the seismic isolation device is installed, and in the lid, and an opening is formed that allows a portion of the area partitioned by the formwork plate to be opened. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2018-178603 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The seismic isolation foundation forming device described in Patent Document 1 also has the same problems as the seismic isolation foundation equipped with the above-mentioned base plate, since it uses a base plate as a component.

[0009] The present invention has been made in view of the above problems, and aims to provide a seismic isolation foundation and a construction method thereof that eliminates the need for expensive base plates and the time-consuming work of ensuring flatness on the top surface of the foundation concrete, while allowing the vertical load acting from the seismic isolation device to act as evenly as possible on the area on the top surface of the foundation concrete where the seismic isolation device is placed, thereby suppressing the occurrence of stress concentration points. [Means for solving the problem]

[0010] To achieve the above objective, one embodiment of the seismic isolation foundation according to the present invention is: A seismic isolation foundation on which seismic isolation devices are installed, Foundation concrete and The present invention is characterized by having an unevenness adjustment material provided in the area on the top surface of the foundation concrete on which the seismic isolation device is placed.

[0011] According to this embodiment, since an unevenness adjustment material is provided in the area on the top surface of the foundation concrete on which the seismic isolation device is placed, even if there is some unevenness (irregularity) in the top surface of the foundation concrete, the unevenness adjustment material can absorb the irregularities in the top surface and make surface contact with the entire area on which the unevenness adjustment material is installed on the top surface. As a result, it becomes possible to eliminate the need for an expensive base plate and the time-consuming work of ensuring flatness in the top surface of the foundation concrete, while allowing the vertical load acting from the seismic isolation device to act as evenly as possible on the area on the foundation concrete on which the seismic isolation device is placed via the unevenness adjustment material, thereby suppressing the occurrence of stress concentration points.

[0012] Herein, in this specification, "concrete" includes not only literal concrete but also mortar (including high-flow mortar), and therefore encompasses all cement-based materials.

[0013] In the foundation concrete, for example, long nuts are embedded around the leveling material, and anchor bolts are further embedded below the long nuts, screwed into them. The upper end of the long nut faces the top surface of the foundation concrete, and the bolt holes opened in the lower plate of the seismic isolation device are aligned with the long nut. By inserting bolts through these holes, the seismic isolation foundation and the seismic isolation device are bolted together.

[0014] Furthermore, other embodiments of the seismic isolation foundation according to the present invention are: A seismic isolation foundation on which seismic isolation devices are installed, Foundation concrete and A frame-shaped plate is embedded in the area on the top surface of the aforementioned foundation concrete where the seismic isolation device is placed, The present invention is characterized by having an unevenness adjustment material provided in the inner region or the region spanning the upper part of the frame-shaped plate on the top surface.

[0015] According to this embodiment, a frame-shaped plate is embedded in the area on the top surface of the foundation concrete on which the seismic isolation device is placed, and a leveling material is provided in the area inside or above the frame-shaped plate on the top surface. Bolt holes are made in the frame-shaped plate, and long nuts are fixed to the positions corresponding to the bolt holes on the lower surface of the frame-shaped plate, allowing the upper end of the anchor bolt to be screwed into the long nuts. Furthermore, even if there is some unevenness (unevenness) on the top surface of the foundation concrete, the leveling material can absorb the unevenness on the top surface and make surface contact with the entire area where the leveling material is installed on the top surface. This makes it possible to apply the vertical load acting from the seismic isolation device as evenly as possible to the area on the foundation concrete on which the seismic isolation device is placed via the leveling material, thereby suppressing the occurrence of stress concentration points.

[0016] Here, the "inner region of the frame-shaped plate" refers to the region on the top surface of the foundation concrete that is inside the frame-shaped plate and does not overlap with the frame-shaped plate. The "region straddling the upper part of the frame-shaped plate" refers to the region on the top surface of the foundation concrete that surrounds the frame-shaped plate. The forms include those where the outer frame of the frame-shaped plate coincides with the outer frame of the unevenness adjusting material, those where the outer frame of the unevenness adjusting material is located outside the outer frame of the frame-shaped plate (the dimensions of the unevenness adjusting material are relatively larger than those of the frame-shaped plate), and those where the outer frame of the unevenness adjusting material is located inside the outer frame of the frame-shaped plate (the dimensions of the unevenness adjusting material are relatively smaller than those of the frame-shaped plate).

[0017] In the former form, that is, the form where the unevenness adjusting material is in the inner region of the frame-shaped plate, the unevenness adjusting material is embedded inside the top surface of the concrete, and forms where the top surface of the concrete and the surface of the unevenness adjusting material are flush, or the unevenness adjusting material is placed on the top surface of the concrete are included.

[0018] On the other hand, in the latter form, that is, the form where the unevenness adjusting material is in the region straddling the upper part of the frame-shaped plate, bolt holes are provided at positions corresponding to the bolt holes of the frame-shaped plate in the unevenness adjusting material, and the two bolt holes are in communication.

[0019] Another aspect of the seismic isolation foundation according to the present invention is characterized in that the unevenness adjusting material is a viscoelastic body or a rubber elastic body.

[0020] According to this aspect, since the unevenness adjusting material is a viscoelastic body or a rubber elastic body, the unevenness adjusting material can effectively absorb the unevenness of the top surface of the foundation concrete and can make surface contact over the entire installation region of the unevenness adjusting material on the top surface.

[0021] Another aspect of the seismic isolation foundation according to the present invention is characterized in that the viscoelastic body is natural rubber and the rubber elastic body is synthetic rubber.

[0022] According to this aspect, since the viscoelastic body is natural rubber and the rubber elastic body is synthetic rubber, the unevenness adjusting material can effectively absorb the unevenness of the top surface of the base concrete and make surface contact with the entire installation area of the unevenness adjusting material on the top surface.

[0023] Moreover, another aspect of the seismic isolation foundation according to the present invention is characterized in that the unevenness adjusting material is a woven fabric or a non-woven fabric.

[0024] According to this aspect, since the unevenness adjusting material is a woven fabric or a non-woven fabric, the unevenness adjusting material can effectively absorb the unevenness of the top surface of the base concrete and make surface contact with the entire installation area of the unevenness adjusting material on the top surface.

[0025] Moreover, one aspect of the construction method of the seismic isolation foundation according to the present invention is a construction method of a seismic isolation foundation to which a seismic isolation device is attached, including a base concrete construction step of installing a frame-shaped formwork and filling the inside of the formwork with concrete to construct the base concrete, and an unevenness adjusting material installation step of installing an unevenness adjusting material in an area where the seismic isolation device is placed on the top surface of the base concrete, characterized by having these steps.

[0026] According to this aspect, after constructing the base concrete, by installing an unevenness adjusting material in the area where the seismic isolation device is placed on the top surface of the base concrete to construct the seismic isolation foundation, it is possible to eliminate the need for an expensive base plate, and while eliminating the need for the laborious work of ensuring flatness on the top surface of the base concrete, the vertical load acting from the seismic isolation device can be made to act as evenly as possible on the area where the seismic isolation device is placed on the top surface of the base concrete, and a seismic isolation foundation capable of suppressing the occurrence of stress concentration points can be constructed.

[0027] Moreover, another aspect of the construction method of the seismic isolation foundation according to the present invention is a construction method of a seismic isolation foundation to which a seismic isolation device is attached, A foundation concrete construction process involves setting up a frame-shaped formwork, installing a frame-shaped plate inside the upper part of the formwork, filling the inside of the formwork with concrete, and constructing a foundation concrete in which the frame-shaped plate is embedded on the top surface. The present invention is characterized by having a step of installing an unevenness adjustment material, which involves installing an unevenness adjustment material in the area inside or over the frame-shaped plate on the top surface of the foundation concrete.

[0028] According to this embodiment, after constructing the foundation concrete with a frame-shaped plate embedded in the top surface, a leveling material is installed in the area on the top surface of the foundation concrete where the seismic isolation device is placed to construct the seismic isolation foundation, or by constructing the foundation concrete with the frame-shaped plate and leveling material embedded in the top surface, it is possible to construct a seismic isolation foundation that eliminates the need for an expensive base plate and the time-consuming work of ensuring flatness on the top surface of the foundation concrete, while allowing the vertical load acting from the seismic isolation device to act as evenly as possible on the area on the top surface of the foundation concrete where the seismic isolation device is placed, thereby suppressing the occurrence of stress concentration points. Here, the method of installing the leveling material in the area on the top surface of the foundation concrete where the seismic isolation device is placed includes a method in which a depression is made inside the frame-shaped plate and concrete is filled in and the leveling material is placed in the depression, and a method in which the leveling material is installed inside the frame-shaped plate and concrete is filled in. [Effects of the Invention]

[0029] As can be understood from the above explanation, the seismic isolation foundation and its construction method of the present invention eliminate the need for expensive base plates and the time-consuming work of ensuring flatness on the top surface of the foundation concrete, while allowing the vertical load acting from the seismic isolation device to act as evenly as possible on the area on the top surface of the foundation concrete where the seismic isolation device is placed, thereby suppressing the occurrence of stress concentration points. [Brief explanation of the drawing]

[0030] [Figure 1]This is a process diagram of an example of a construction method for a seismic isolation foundation according to the first embodiment. [Figure 2] Following Figure 1, this is a process diagram illustrating an example of a construction method for a seismic isolation foundation according to the first embodiment. [Figure 3] Following Figure 2, this is a process diagram of an example of a construction method for a seismic isolation foundation according to the first embodiment, and is a longitudinal cross-sectional view of an example of a seismic isolation foundation according to the first embodiment. [Figure 4] This is a view taken in the direction of arrow IV in Figure 3, and is a plan view of an example of a seismic isolation foundation according to the first embodiment. [Figure 5] This is a longitudinal cross-sectional view showing the seismic isolation device attached to the seismic isolation foundation according to the first embodiment. [Figure 6] This is a process diagram of an example of a construction method for a seismic isolation foundation according to the second embodiment. [Figure 7] Following Figure 6, this is a process diagram of an example of a construction method for a seismic isolation foundation according to the second embodiment. [Figure 8] Following Figure 7, this is a process diagram of an example of a construction method for a seismic isolation foundation according to the second embodiment, and is a longitudinal cross-sectional view of an example of a seismic isolation foundation according to the second embodiment. [Figure 9] This is a view in the direction of arrow IX in Figure 8, and is a plan view of an example of a seismic isolation foundation according to the second embodiment. [Figure 10] This figure corresponds to Figure 8 and is a process diagram of another example of the construction method for the seismic isolation foundation according to the second embodiment. [Modes for carrying out the invention]

[0031] The seismic isolation foundations and their construction methods according to each embodiment will be described below with reference to the attached drawings. In this specification and the drawings, substantially identical components may be denoted by the same reference numerals to avoid redundant explanations.

[0032] [Seismic isolation foundation and its construction method according to the first embodiment] First, an example of a seismic isolation foundation and its construction method according to the first embodiment will be described with reference to Figures 1 to 5. Here, Figures 1 to 3 are, in order, process diagrams of an example of a construction method for a seismic isolation foundation according to the first embodiment, Figure 3 is a longitudinal cross-sectional view of an example of a seismic isolation foundation according to the first embodiment, and Figure 4 is a view in the direction of arrow IV in Figure 3, and is a plan view of an example of a seismic isolation foundation according to the first embodiment.

[0033] The following describes a method for constructing a seismic isolation foundation 100 having a rectangular (square in the illustrated example) rectangular foundation concrete 30 in plan view. However, the outer shape of the foundation concrete to be constructed may be a polygonal column shape other than a square in plan view, or it may be cylindrical, elliptical, etc. Also, the illustration of the reinforcement embedded in the foundation concrete 30 is omitted.

[0034] As shown in Figure 1, a rectangular frame-shaped formwork 10 (side frame) is installed at a predetermined position on the construction surface F at the site. Note that the illustration of support members and other components that support the formwork 10 from the outside is omitted.

[0035] A nut anchor unit 28, in which a long nut 20 and the upper part of an anchor bolt 25 are screwed into the bolt hole 22 of the long nut 20 are installed inside the upper part of the frame-shaped formwork 10 via a support member (not shown) extending from the formwork 10. In the illustrated construction method, as shown in Figure 4, eight nut anchor units 28 are arranged at equal intervals in the circumferential direction, so each nut anchor unit 28 is installed, for example, from a nearby formwork 10 via a support member (not shown).

[0036] In this illustrated example, the upper end of the formwork 10 and the upper end of the long nut 20 are made flush, and concrete is filled up to the upper ends of both.

[0037] After placing reinforcing bars for the foundation concrete (not shown) inside the formwork 10, concrete is filled into the formwork 10 up to its upper end, embedding the reinforcing bars (not shown) and nut anchor units 28 in the concrete as shown in Figure 2, and after waiting for a predetermined curing period, the foundation concrete 30 is constructed (foundation concrete construction process).

[0038] In the construction of the foundation concrete 30, the top surface 31 of the concrete is flattened to a certain extent by troweling or the like before the concrete hardens. However, it is not necessary to achieve a high degree of flatness in this finish; a finish that is reasonably flat is sufficient.

[0039] Furthermore, even after the concrete has hardened, there is no need for time-consuming work such as grinding or adding material to achieve a high degree of flatness on the top surface 31.

[0040] Next, as shown in Figures 3 and 4, the formwork 10 is removed, and the seismic isolation foundation 100 is constructed by installing unevenness adjustment material 40 in the area on the top surface 31 of the foundation concrete 30 where the seismic isolation device 200 (see Figure 5) will be placed.

[0041] As shown in Figure 4, a circular unevenness adjustment material 40 is installed in the center of the top surface 31 of the foundation concrete 30, and multiple (eight in the illustrated example) long nuts 20 are embedded around the top surface 31 of the unevenness adjustment material 40 at intervals in the circumferential direction, with their bolt holes 22 facing upward.

[0042] The leveling material 40 in the illustrated example is a thin, plate-like body with a circular shape in plan view, corresponding to the planar shape of the lower plate 210 of the seismic isolation device 200, and only needs to be placed on the top surface 31 of the foundation concrete 30. The planar shape of the leveling material may also be a rectangle (square or rectangle) or a polygon other than a rectangle in plan view, and various planar shapes can be applied depending on the planar shape of the lower plate of the seismic isolation device.

[0043] Here, the unevenness adjustment material 40 is formed from a material that can deform appropriately and make surface contact with the entire area of ​​unevenness (undulations) present on the top surface 31, for example, from a viscoelastic material or a rubber elastic material.

[0044] Examples of viscoelastic materials include natural rubber, while examples of rubber-elastic materials include synthetic rubber. Examples of synthetic rubber include acrylic rubber, urethane rubber, ethylene vinyl acetate rubber (EVA), ethylene propylene diene rubber (EPDM), chloroprene rubber, styrene butadiene rubber, and butyl rubber.

[0045] The unevenness adjustment material 40 may also be woven fabric or nonwoven fabric (the above is the unevenness adjustment material installation process).

[0046] As shown in Figure 5, the seismic isolation device 200 is installed on the constructed seismic isolation foundation 100. Here, the seismic isolation device 200 in the illustrated example is a device in which laminated rubber is sandwiched between an upper plate and a lower plate 210, but various structures and mechanisms of seismic isolation devices such as sliding seismic isolation devices may be applied.

[0047] In the lower plate 210 of the seismic isolation device 200, bolt holes 212 are provided at positions corresponding to the bolt holes 22 of each long nut 20 facing the top surface 31 of the foundation concrete 30. By inserting bolts 250 through the mutually aligned bolt holes 212, 22, the seismic isolation foundation 100 and the seismic isolation device 200 are bolted together with multiple bolts 250.

[0048] According to the seismic isolation foundation 100 constructed using the illustrated construction method, the unevenness adjustment material 40 is provided in the area on the top surface 31 of the foundation concrete 30 where the seismic isolation device 200 is placed. As a result, even if there is some unevenness (undulation) on the top surface 31 of the foundation concrete 30, the unevenness adjustment material 40 can absorb the unevenness on the top surface 31 and make surface contact with the entire area where the unevenness adjustment material 40 is installed on the top surface 31. This eliminates the need for an expensive base plate and the time-consuming work of ensuring the flatness of the top surface of the foundation concrete, while allowing the vertical load acting from the seismic isolation device 200 to act as evenly as possible across the entire area on the foundation concrete 30 where the seismic isolation device 200 is placed via the unevenness adjustment material 40, thereby suppressing the occurrence of stress concentration points.

[0049] Furthermore, the inventors have modeled the foundation concrete and the leveling material installed on it as finite element models in a computer, simulated a convex portion on the top surface of the foundation concrete model, and then applied a vertically distributed load to the top surface to perform an analysis to verify whether or not stress concentration points occur on the top surface with and without the leveling material.

[0050] In this analysis model, both the foundation concrete and the leveling material are treated as solid elements, and the two models are connected by compression-only elements. This sets a condition where no stress is placed on the two models in the direction of separation. By inputting the gap value of these compression-only elements, the irregularities on the top surface of the foundation concrete are simulated.

[0051] The analysis results showed that in the analysis model without unevenness adjustment material, stress concentration occurred in the convex region of the top surface, while in the analysis model with unevenness adjustment material, no stress concentration occurred on the top surface. This verifies that even when convex (unevenness) is present on the top surface, the occurrence of stress concentration can be suppressed by unevenness adjustment material.

[0052] [Seismic isolation foundation and its construction method according to the second embodiment] Next, an example of a seismic isolation foundation and its construction method according to the second embodiment will be described with reference to Figures 6 to 10. Here, Figures 6 to 8 are, in order, process diagrams of an example of a construction method for a seismic isolation foundation according to the second embodiment. Figure 8 is a longitudinal cross-sectional view of an example of a seismic isolation foundation according to the second embodiment, and Figure 9 is a view in the direction of arrow IX in Figure 8, and is a plan view of an example of a seismic isolation foundation according to the second embodiment. Figure 10 is a diagram corresponding to Figure 8, and is a process diagram of another example of a construction method for a seismic isolation foundation.

[0053] The construction method shown in the illustration differs from the construction method according to the first embodiment for constructing the seismic isolation foundation 100, in that the seismic isolation foundation 100A (see Figures 8 and 9) to be constructed has a frame-shaped plate 50 on the top surface 31 of the foundation concrete 30.

[0054] As shown in Figure 6, a rectangular frame-shaped formwork 10 (side frame) is installed at a predetermined position on the construction surface F at the site.

[0055] When installing the frame-shaped plate 50 inside the upper part of the frame-shaped formwork 10, the frame-shaped plate 50 is provided with multiple bolt holes 52 at intervals (see Figure 9), and the upper ends of long nuts 20, each having a bolt hole 22, are welded to the lower surface of the frame-shaped plate 50 at positions corresponding to each bolt hole 52, and the upper part of an anchor bolt 25 is screwed into the bolt hole 22 of each long nut 20.

[0056] Furthermore, height adjustment jigs (not shown) are installed at multiple locations on the underside of the frame-shaped plate 50 where there are no bolt holes 52, and the frame-shaped plate 50 is placed on multiple height adjustment jigs whose heights have already been adjusted. The frame-shaped plate 50 is, for example, a steel plate and has a square shape in plan view that is smaller than the plan view dimensions of the formwork 10.

[0057] After reinforcing bars for the foundation concrete (not shown) are placed inside the formwork 10, the leveling material 40 is installed inside the frame-shaped plate 50, as shown in Figure 7. Here, the upper surfaces of both the leveling material 40 and the frame-shaped plate 50 are flush. More specifically, the leveling material 40 is installed so that the upper surfaces of both are flush, taking into account the amount of compression shrinkage of the leveling material 40 (leveling material installation process).

[0058] Next, concrete is filled into the formwork 10 up to its upper end, with reinforcing bars (not shown), frame-shaped plates 50, long nuts 20, anchor bolts 25, and unevenness adjustment material 40 embedded in the concrete, and after waiting for a predetermined curing period, the foundation concrete 30 is poured (foundation concrete pouring process). The seismic isolation foundation 100A is then constructed by removing the formwork 10 as shown in Figures 8 and 9.

[0059] Here, the illustrated example shows a method in which the leveling material 40 is installed in the formwork prior to the concrete filling. However, it is also possible to fill the formwork with concrete while a space (recess) for installing the leveling material 40 is provided inside the frame-shaped plate 50, and then install the leveling material 40 in this recess. In this case, the leveling material installation process is carried out following the foundation concrete construction process.

[0060] As shown in Figure 9, a circular unevenness adjustment material 40 is installed in the center of the top surface 31 of the foundation concrete 30, and a frame-shaped plate 50 is embedded in the top surface 31 around the unevenness adjustment material 40, with multiple (eight in the illustrated example) bolt holes 52 spaced apart in the circumferential direction. Here, since the frame-shaped plate 50 does not have a large surface area like a normal base plate and does not require surface processing to achieve high flatness, the manufacturing cost is not as high as that of a base plate.

[0061] For example, in the seismic isolation device 200 shown in Figure 5, each bolt hole 212 of the lower plate 210 is aligned with each bolt hole 52 of the frame-shaped plate 50, and bolts 250 are inserted sequentially through the bolt holes 212, 52, and 22, thereby bolting the seismic isolation foundation 100A and the seismic isolation device 200 together with multiple bolts 250.

[0062] Here, instead of the leveling material 40 shown in Figures 7 to 9, a method may be used in which, as shown in Figure 10, a leveling material 40A having an area that surrounds the frame-shaped plate 50 is installed above the frame-shaped plate 50 and on the top surface 31 of the foundation concrete 30.

[0063] Among the unevenness adjustment material 40A, through holes 42 are provided at positions corresponding to the bolt holes 52 of the frame-shaped plate 50, and bolts 250 are inserted through the corresponding through holes 42 and bolt holes 52.

[0064] Furthermore, other embodiments may be used in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited in any way to the configurations shown herein. In this regard, modifications can be made without departing from the spirit of the present invention, and can be appropriately determined according to the application form. [Explanation of Symbols]

[0065] 10: Formwork 20: Long nut 22: Bolt holes 25: Anchor bolts 28: Nut Anchor Unit 30: Foundation concrete 31: Top surface 40,40A: Unevenness adjustment material 42: Through hole 50: Frame-shaped plate 52: Bolt holes 100, 100A: Seismic isolation foundation 200: Seismic isolation device 210: Lower plate 212: Bolt hole 250: Bolt

Claims

1. A seismic isolation foundation on which seismic isolation devices are installed, Foundation concrete and A seismic isolation foundation characterized by having a leveling material provided in the area on the top surface of the foundation concrete on which the seismic isolation device is placed.

2. A seismic isolation foundation on which seismic isolation devices are installed, Foundation concrete and A frame-shaped plate is embedded in the area on the top surface of the aforementioned foundation concrete where the seismic isolation device is placed, A seismic isolation foundation characterized by having an unevenness adjustment material provided in the inner region or region spanning the upper part of the frame-shaped plate on the top surface.

3. The seismic isolation foundation according to claim 1 or 2, characterized in that the unevenness adjustment material is a viscoelastic body or a rubber elastic body.

4. The seismic isolation foundation according to claim 3, characterized in that the viscoelastic body is natural rubber and the rubber elastic body is synthetic rubber.

5. The seismic isolation foundation according to claim 1 or 2, characterized in that the unevenness adjustment material is a woven fabric or a nonwoven fabric.

6. A method for constructing a seismic isolation foundation, on which seismic isolation devices are installed, The foundation concrete construction process involves setting up a frame-shaped formwork and filling the inside of the formwork with concrete to construct the foundation concrete, A method for constructing a seismic isolation foundation, characterized by comprising a step of installing an unevenness adjustment material in the area on the top surface of the foundation concrete on which the seismic isolation device is placed.

7. A method for constructing a seismic isolation foundation, on which seismic isolation devices are installed, A foundation concrete construction process involves setting up a frame-shaped formwork, installing a frame-shaped plate inside the upper part of the formwork, filling the inside of the formwork with concrete, and constructing a foundation concrete in which the frame-shaped plate is embedded on the top surface. A method for constructing a seismic isolation foundation, characterized by comprising a step of installing an unevenness adjustment material in the area inside or above the frame-shaped plate on the top surface of the foundation concrete.

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