JP7125193B2 - Seismic isolation structure - Google Patents

Description

The present invention relates to a seismic isolation structure.

Patent Literature 1 below discloses a seismic isolation device that exerts a seismic isolation effect by sliding elastic slide bearings, which are fixed to an upper structure and provided with laminated rubber, on a slide plate fixed to a lower structure. there is

JP-A-11-210823

In the seismic isolation device shown in Patent Document 1, when an earthquake occurs, each elastic sliding bearing slides on the sliding plate, but after the earthquake, the position of the upper structure (structure) and the lower structure (support plate) It is difficult to restore the seismic isolation device so that the relationship is in the original state.

SUMMARY OF THE INVENTION In consideration of the above facts, it is an object of the present invention to provide a seismic isolation structure that facilitates restoration of the seismic isolation device after an earthquake.

A seismic isolation structure according to claim 1 comprises a structure that is a building, a plurality of seismic isolation devices for seismically isolating and supporting the structure, one support plate to which all of the plurality of seismic isolation devices are fixed, and the A support plate is placed thereon, and before the seismic isolation device begins to plastically deform, the support plate slides on a base portion , provided between the support plate and the base portion, and is broken by receiving a predetermined horizontal force. and a sliding suppression member .

According to the seismic isolation structure of claim 1, when the deformation of the seismic isolation device exceeds a predetermined value due to an earthquake, the support plate to which the seismic isolation device is fixed slides on the foundation, so damage to the seismic isolation device can be suppressed. . In addition, after the slide starts, the seismic energy can be consumed by the frictional force between the support plate and the foundation.

The seismic isolation device is fixed to the support plate, and the structure, the seismic isolation device and the support plate slide together. Therefore, compared to a configuration in which each seismic isolation device provided with a slip member slides on a support plate, the structure and the support plate are relatively less likely to be displaced, and the seismic isolation structure can be easily restored. Moreover, damage to the piping arranged between the structure and the support plate can be suppressed.

Furthermore, since it is sufficient to secure the sliding space around the support plate, it is easier to secure the sliding space than to secure a sliding space for each seismic isolation device by providing a sliding material for each seismic isolation device. The seismic device can also be arranged densely.
In the seismic isolation structure according to claim 2, the coefficient of static friction between the support plate and the base is set to a value that allows the support plate to start sliding before the seismic isolation device starts plastic deformation. .
In one aspect of the seismic isolation structure, a plurality of the support plates are provided, and a plurality of the seismic isolation devices are fixed to each of the support plates.

In one aspect of the seismic isolation structure, a sliding suppressing member that breaks when receiving a predetermined horizontal force is provided between the support plate and the base portion.

According to one aspect of the seismic isolation structure, the timing at which the support plate starts to slide can be adjusted by changing the breaking strength of the anti-slip member.
In the seismic isolation structure according to claim 3 , the anti-slip member is inserted into an insertion hole penetrating through the support plate from the upper part of the support plate and reaching the inside of the base portion.
In the seismic isolation structure according to claim 4 , the sliding suppressing member is made of concrete.
In the seismic isolation structure according to claim 5 , a lead plug is inserted inside the seismic isolation device.

In the seismic isolation structure according to claim 6 , the structure is a nuclear-related facility.

Since the weight of the entire building of a nuclear power facility is large, a large number of seismic isolation devices are required, and the pitch of the installation is also fine. For this reason, when a sliding member is provided for each seismic isolation device, there is a possibility that a sufficient sliding area cannot be secured.

In the seismic isolation structure of claim 6 , the seismic isolation device is fixed to the support plate, and the support plate slides on the foundation, so there is no need to secure a sliding material and a sliding space for each seismic isolation device. All you have to do is secure a sliding space for the support plate around the related facilities.

Further, when the deformation of the seismic isolation device reaches or exceeds a predetermined value, the support plate to which the seismic isolation device is fixed slides on the foundation, thereby suppressing damage to the seismic isolation device. As a result, the seismic isolation device can maintain the state of supporting the weight of the building even in the event of a large earthquake. Therefore, it is easy to maintain the soundness of the building.

According to the seismic isolation structure according to the present invention, it is easy to restore the seismic isolation device after an earthquake.

1 is an elevation cross-sectional view showing a seismic isolation structure according to an embodiment of the present invention; FIG. (A) is a partially enlarged elevational sectional view showing a modification in which the contact surface between the base portion and the support plate is formed of a steel plate in the seismic isolation structure according to the embodiment of the present invention, and (B) is a base portion and the support plate. and FIG. 11 is a partially enlarged vertical cross-sectional view showing a modified example in which a sliding material is sandwiched between. (A) is a vertical cross-sectional view showing a state in which the laminate of the seismic isolation device is deformed during an earthquake in the seismic isolation structure according to the embodiment of the present invention; (C) shows the state after the earthquake. It is an elevation sectional view showing the method of restoring the seismic isolation structure which concerns on embodiment of this invention after an earthquake. It is an elevation sectional view which shows the modification which provided multiple supporting plates in the seismic isolation structure which concerns on embodiment of this invention. (A) is a cross-sectional elevational view showing a modification in which the shear stopper is made of concrete in the seismic isolation structure according to the embodiment of the present invention, and (B) is a concrete shear stopper formed in the shape of a part of a cone. It is a partially enlarged vertical cross-sectional view showing a modification, and (C) is a perspective view showing a modification in which a slit is formed in the shear stopper.

(Seismic isolation structure)
As shown in FIG. 1, the seismic isolation structure 10 according to the present embodiment includes a structure 20, a plurality of seismic isolation devices 30 for supporting the structure in seismic isolation, a support plate 40 to which the seismic isolation devices are fixed, and a base portion 50 on which the support plate 40 is placed.

Furthermore, a shear stopper 60 is provided between the support plate 40 and the base portion 50 as a sliding suppression member that prevents the support plate 40 from sliding on the upper portion of the base portion 50 .

(Structure)
The structure 20 is assumed to be a nuclear power related facility, and has a larger gross weight than other buildings of the same scale, and a large seismic force, which is assumed due to its importance. For this reason, a larger number of seismic isolation devices 30 for supporting the structure 20 are installed compared to other-purpose buildings of the same scale.

(Seismic isolation device)
The seismic isolation device 30 includes an upper flange 32 fixed to the structure 20, a lower flange 34 fixed to the support plate 40, and a laminate 36 having upper and lower ends fixed to the upper flange 32 and the lower flange. ing. The laminated body 36 is constructed by alternately laminating and bonding rubber and steel plates, and is resistant to deformation against vertical (vertical) force and resistant to lateral (horizontal) force. Cheap. Therefore, when a horizontal force is applied to the structure 20 during an earthquake, the laminate 36 can be deformed to absorb the vibration energy.

(support plate, foundation)
The support slab 40 is a floor slab made of reinforced concrete placed on the upper part of the foundation 50 and supports the structure 20 via the seismic isolation device 30 . All of the seismic isolation devices 30 are fixed on the upper part of the support plate 40, and equipment pipes of the structure 20 (not shown) are laid.

The foundation part 50 is made of reinforced concrete and is formed at the bottom (root cut bottom) of an underground space formed by excavating the ground G. A retaining wall 54 is erected on the outer peripheral portion of the foundation portion 50 to form an underground pit that resists earth pressure from the ground G or water pressure from groundwater. Note that the foundation portion 50 does not necessarily have to be formed in the underground space, and can be formed on the ground surface without excavating the ground G. Moreover, in this case, the retaining wall 54 may not be provided.

The concrete forming the support plate 40 is installed after the concrete forming the base portion 50 hardens. As a result, the edge between the support plate 40 and the base portion 50 is cut, and the support plate 40 can slide on the upper portion of the base portion 50 when the support plate 40 receives a horizontal force due to an earthquake. Since the ground G moves during an earthquake, a seismic force is input from the ground G to the support plate 40 via the base portion 50 .

Although details will be described later, in this embodiment, the horizontal force at which the support plate 40 starts sliding, that is, (coefficient of static friction between the support plate 40 and the base portion 50) × (vertical force: the support plate 40 and the support plate 40) is set smaller than the horizontal force at which the seismic isolation device 30 begins plastic deformation. In other words, the coefficient of static friction between the support plate 40 and the base portion 50 is set to a value that allows the support plate 40 to start sliding before the seismic isolation device 30 starts plastic deformation.

The static friction coefficient and the dynamic friction coefficient when the support plate 40 slides on the upper portion of the base portion 50 can be set to arbitrary values depending on the finishing method of the contact surfaces 40E, 50E of the support plate 40 and the base portion 50.

For example, in the present embodiment, the contact surfaces 40E and 50E are concrete surfaces, but both of them may be steel plate surfaces. In this case, as shown in FIG. 2A, a steel plate 52 is fixed to the surface of the concrete forming the foundation 50 using stud bolts or the like. Similarly, a steel plate 42 is also fixed to the concrete surface forming the support plate 40 .

As a result, the static friction coefficient and dynamic friction coefficient (hereinafter collectively referred to simply as friction coefficients) when the support plate 40 slides on the upper portion of the base portion 50 can be reduced. Further, by making either or both of the steel plates 42 and 52 a metal other than steel, the coefficient of friction can be adjusted.

Also, one of the contact surfaces 40E and 50E may be a concrete surface and the other may be a steel plate surface. In this case, the steel plate may be fixed to either the surface of the concrete forming the base portion 50 or the surface of the concrete forming the support plate 40 using stud bolts or the like.

Further, for example, as shown in FIG. 2B, a configuration in which a sliding member 44 is sandwiched between the support plate 40 and the base portion 50 may be employed. Any material such as metal or fluorine resin can be selected for the sliding member 44 .

(Shear stopper)
As shown in FIG. 1, the shear stopper 60 is a cylindrical steel rod, and is arranged with its axial direction extending vertically so as to penetrate the contact surfaces 40E and 50E of the support plate 40 and the base portion 50. As shown in FIG.

The shear stopper 60 is a sliding suppression member that suppresses sliding of the support plate 40 when a horizontal force acts on the support plate 40 during an earthquake. Further, the shear stopper 60 is sheared and broken when receiving a predetermined horizontal force to allow the support plate 40 to slide. Therefore, by adjusting the number and cross-sectional area of the shear stoppers 60, the timing at which the support plate 40 starts to slide over the base portion 50 can be adjusted.

That is, the horizontal force at which the shear stopper 60 breaks is given by (shear strength per unit area of the steel material forming the shear stopper 60)×(cross-sectional area of the shear stopper 60)×(number of shear stoppers). If the cross-sectional area of the sear stopper 60 is increased, the horizontal force required to break the sear stopper 60 is increased, and the timing at which the support plate 40 slides over the base portion 50 can be delayed. Even if the number of shear stoppers 60 is increased, the same is true.

Further, if the cross-sectional area of the sear stopper 60 is reduced, the horizontal force required to break the sear stopper 60 is reduced, and the timing at which the support plate 40 slides over the base portion 50 can be advanced. Even if the number of sear stoppers 60 is reduced, the same is true.

Although details will be described later, in this embodiment, the cross-sectional area and quantity of the shear stoppers are set so that the horizontal force at which the shear stopper 60 breaks is smaller than the horizontal force at which the seismic isolation device 30 starts plastic deformation. . In other words, the shear stopper 60 breaks before the seismic isolation device 30 starts plastic deformation.

(action/effect)
According to the seismic isolation structure 10 according to this embodiment, when the structure 20 receives a horizontal force during an earthquake, as shown in FIG. It absorbs energy and attenuates the shaking transmitted to the structure 20. - 特許庁

In the event of a major earthquake, as shown in FIG. 3B, the shear stopper 60 breaks (separates into shear stoppers 60A and 60B) before the seismic isolation device 30 starts plastic deformation, and the support plate 40 moves above the foundation 50. to slide.

As a result, damage to the seismic isolation device 30 can be suppressed. Furthermore, when the support plate 40 slides on the base portion 50, the seismic energy is absorbed by the dynamic frictional force between the support plate 40 and the base portion 50, and the vibration is damped.

Since the plastic deformation of the seismic isolation device 30 is suppressed, after the vibration is damped, the shape of the seismic isolation device 30 generally returns to the state before deformation, as shown in FIG. 3(C). Therefore, the relative positional relationship between the structure 20 and the support plate 40 substantially matches the state before the earthquake shown in FIG. Also, the facility piping of the structure 20 laid on the support plate 40 is restored to substantially the same arrangement as before the earthquake.

For this reason, damage can be easily suppressed by providing the facility piping with followability that can correspond to the amount of deformation in which the laminate 36 of the seismic isolation device 30 deforms in the elastic region.

In order to restore the seismic isolation structure 10, as shown in FIG.
0H is drilled, and the shear stopper 60 is inserted into this insertion hole 40H. Thus, the seismic isolation structure 10 can be easily restored.

Moreover, according to the seismic isolation structure 10 according to the present embodiment, as shown in FIG. The seismic device 30 is similarly deformed. Therefore, even if the distance between the adjacent seismic isolation devices 30 is narrowed, the seismic isolation devices 30 do not collide with each other. Therefore, it is not necessary to secure individual sliding spaces around each seismic isolation device 30, and it is only necessary to collectively secure a sliding space V between the support plate 40 and the retaining wall 54. - 特許庁

In this embodiment, the coefficient of static friction between the support plate 40 and the base portion 50 is set to a value that allows the support plate 40 to start sliding before the seismic isolation device 30 starts plastic deformation. However, the embodiment of the present invention is not limited to this. For example, the coefficient of static friction between the support plate 40 and the base portion 50 is set to a value that allows the support plate 40 to start sliding after the base isolation device 30 starts plastic deformation (or at the same time as it starts plastic deformation). Can also be set.

By setting the coefficient of static friction in this manner, the vibration damping ability of the seismic isolation device 30 can be sufficiently exhibited. Such an embodiment is suitable for damping vibration by inserting a lead plug into the seismic isolation device and plastically deforming the lead plug.

Similarly, in the present embodiment, the shear stopper 60 is broken before the seismic isolation device 30 starts plastic deformation, but the embodiment of the present invention is not limited to this. For example, the shear strength or cross-sectional area of the shear stopper 60 may be increased to break the shear stopper 60 after the seismic isolation device 30 starts plastic deformation (or at the same time as it starts plastic deformation). With such a configuration as well, the vibration damping ability of the seismic isolation device 30 can be fully exhibited.

That is, the coefficient of static friction between the support plate 40 and the base portion 50, the shear strength of the shear stopper 60, and the cross-sectional area are arbitrary. can be set as appropriate. Therefore, the structure 20 is not limited to a nuclear-related facility, and may be a private residence, an art museum, an office building, or the like, regardless of the size and usage.

When the seismic isolation device 30 is plastically deformed, the amount of deformation of the seismic isolation device may become larger than when it is not plastically deformed. Even in such a case, the amount of relative displacement between the structure 20 and the support plate 40 is small compared to, for example, the case where the seismic isolation device fixed to the structure 20 slides on the support plate 40 . Therefore, damage to the facility piping is suppressed.

Further, in the present embodiment, the support plate 40 is a floor plate and all the seismic isolation devices 30 are fixed, but the embodiment of the present invention is not limited to this. For example, like the support plate 70 shown in FIG. 5, any structure may be used as long as a plurality (two or more) of the seismic isolation devices 30 are fixed. In this configuration, by providing the shear stopper 60 to each of the plurality of support plates 70, the timing of sliding can be adjusted.

Moreover, although the sear stopper 60 is made of steel in this embodiment, the embodiment of the present invention is not limited to this. For example, like a shear stopper 65 shown in FIG. 6A, it may be made of concrete. In this case, the cylindrical male mold is buried so as to be exposed from the surface when concrete is poured for the foundation portion 50 . If the concrete is taken out after hardening, a concave portion is formed in the upper surface of the base portion 50 . Then, the concrete of the support plate 40 is also poured into this concave portion and cast integrally. Thereby, a shear stopper 65 made of concrete is formed.

Note that the shear stopper 65 is not limited to a columnar shape, and may be prismatic, or may have a shape like a part of a cone as shown in FIG. 6(B).

In this manner, the material and outer shape of the shear stopper can be appropriately selected depending on the shear strength required of the shear stopper, the direction in which the shear strength is desired to be increased, and the like. Furthermore, shear strength may be adjusted by providing a slit 60S like a shear stopper 67 shown in FIG. 6(C). In this manner, embodiments of the present invention can have various aspects.

20 Structures (nuclear related facilities)
30 Seismic isolation device 40, 70 Support plate 50 Base portion 60 Shear stopper (slide suppressing member)

Claims (6)

a structure that is a building ;
a plurality of seismic isolation devices for seismically isolating and supporting the structure;
a single support plate to which all of the plurality of seismic isolation devices are fixed;
a base on which the support plate is placed and on which the support plate slides before the seismic isolation device starts plastic deformation;
a sliding suppression member provided between the support plate and the base portion, and broken by receiving a predetermined horizontal force;
seismic isolation structure. 2. The seismic isolation system according to claim 1, wherein the coefficient of static friction between said support plate and said base is set to a value that allows said support plate to start sliding before said base isolation device starts plastic deformation. structure. 3. The seismic isolation structure according to claim 1 , wherein said sliding suppressing member is inserted into an insertion hole extending from an upper portion of said support plate through said support plate and reaching the inside of said base portion. The seismic isolation structure according to claim 3 , wherein said sliding suppression member is made of concrete. The seismic isolation structure according to any one of claims 1 to 4 , wherein a lead plug is inserted inside said seismic isolation device. The structure was considered to be a nuclear related facility,
A seismic isolation structure according to any one of claims 1 to 5 .

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