JP2015055267A - Intermediate base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve habitability of at least the uppermost layer of an upper structure part and the uppermost layer of a lower structure part during an earthquake in an intermediate base isolation structure.SOLUTION: Response acceleration to be inputted from a foundation 800 to an intermediate base isolation structure 100 (a lower structure part 10) during an earthquake is to be reduced by disposing a fundamental base isolation layer 102 in addition to an intermediate base isolation layer 50. This ensures that vibration of the lower structure part 10 is reduced so as to reduce response acceleration of an uppermost layer 12 of the lower structure part 10.

Description

  The present invention relates to an intermediate seismic isolation structure.

  Patent Document 1 discloses an intermediate seismic isolation structure in which a structure composed of a plurality of structures stacked via an intermediate seismic isolation layer is supported by a basic seismic isolation layer.

  Such an intermediate seismic isolation structure is designed to be free from intense shaking by making the natural period longer to avoid resonance with strong short-period ground motion during an earthquake.

  However, the response acceleration may be amplified in the uppermost layer of the lower structure below the middle seismic isolation layer (the layer directly below the middle seismic isolation layer) due to the vibration of the upper structure above the middle seismic isolation layer. Are known. And if the response acceleration of the uppermost layer of a lower structure part is amplified in this way, even if it is an intermediate seismic isolation structure, the habitability of the uppermost layer of the lower structure part at the time of an earthquake will deteriorate.

  In addition, when the upper structure is larger and heavier than the lower structure, the response acceleration of the uppermost layer of the upper structure is not sufficiently reduced. The habitability of the top layer may not be improved sufficiently.

  As described above, in the intermediate seismic isolation structure for the purpose of simply extending the period, there is room for improvement in the habitability of the uppermost layer of the upper structure and the uppermost layer of the lower structure at the time of the earthquake.

Japanese Patent Laid-Open No. 01-263373

  An object of the present invention is to improve the habitability of at least one of the uppermost layer of the upper structure portion and the uppermost layer of the lower structure portion during an earthquake in the intermediate seismic isolation structure.

  According to the first aspect of the present invention, the response acceleration of at least one of the first seismic isolation layer provided between the lower structure portion and the upper structure portion, the uppermost layer of the lower structure portion, and the uppermost layer of the upper structure portion is obtained. Response acceleration reducing means for reducing the response acceleration.

  In the first aspect of the invention, the response acceleration reducing means reduces the stress acceleration of at least one of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion, so that the upper portion at the time of the earthquake in the intermediate seismic isolation structure The swaying of at least one of the uppermost layer of the structure part and the uppermost layer of the lower structure part is reduced, and the comfort is improved.

  According to a second aspect of the present invention, the response acceleration reducing means includes a vibration damping device provided on at least one of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion.

  In the invention described in claim 2, stress acceleration is reduced by providing a vibration damping device in at least one of the uppermost layer of the lower structure and the uppermost layer of the upper structure. The habitability of at least one of the uppermost layer of the upper structure portion and the uppermost layer of the lower structure portion is improved.

  According to a third aspect of the present invention, the response acceleration reducing means has a second seismic isolation layer provided in a layer other than the first seismic isolation layer.

  In the invention according to claim 3, since the second seismic isolation layer provided in a layer other than the first seismic isolation layer reduces response acceleration of at least one of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion. In addition, the habitability of at least one of the uppermost layer of the upper structure and the uppermost layer of the lower structure at the time of the earthquake in the intermediate seismic isolation structure is improved.

  According to the present invention, the habitability of at least one of the uppermost layer of the upper structure portion and the uppermost layer of the lower structure portion at the time of the earthquake in the intermediate seismic isolation structure can be improved.

(A) is an elevational view showing the intermediate seismic isolation structure of the first embodiment, and (B) is an explanatory view showing response acceleration during an earthquake. It is an elevation which shows the middle seismic isolation structure of the 1st modification of a first embodiment. It is an elevation which shows the middle seismic isolation structure of the 2nd modification of a first embodiment. It is an elevation view which shows the intermediate seismic isolation structure of the 3rd modification of 1st embodiment. (A) is an elevation view showing an intermediate seismic isolation structure of a fourth modification of the first embodiment, and (B) is an elevation showing an intermediate isolation structure of the fifth modification of the first embodiment. (C) is an elevation view showing an intermediate seismic isolation structure according to the sixth modification of the first embodiment, and (D) is an intermediate seismic isolation structure according to the seventh modification of the first embodiment. FIG. It is an elevation view which shows the intermediate seismic isolation structure of 2nd embodiment. It is an elevational view showing an intermediate seismic isolation structure of a modification of the second embodiment. It is an elevation view which shows the intermediate seismic isolation structure of 3rd embodiment. It is a structural model of the equivalent two-mass system of the intermediate seismic isolation structure of 1st embodiment shown in FIG. 11 is a graph showing the relationship between the mass ratio γ and the stimulation function β ₁ u ₂ in the structural model of the equivalent two-mass system in FIG. It is an elevational view showing an intermediate seismic isolation structure of a comparative example to which the present invention is not applied.

<First embodiment>
The intermediate seismic isolation structure according to the first embodiment of the present invention will be described.

[Construction]
As shown in FIG. 1A, the intermediate seismic isolation structure 100 includes a lower structure portion 10 and an upper structure portion 20 such as a reinforced concrete structure, a steel reinforced concrete structure, and a steel structure. An intermediate seismic isolation layer 50 is provided between the upper structure portion 20 and the upper structure portion 20. In addition, a base seismic isolation layer 102 is provided between the lower structure 10 and the ground 800. In the present embodiment, the lower structure unit 10 is larger than the upper structure unit 20, and the mass m1 of the lower structure unit 10 is heavier than the mass m2 of the upper structure unit 20 (see FIG. 9).

  A seismic isolation device 60 is installed in the intermediate seismic isolation layer 50. The seismic isolation device 60 includes a laminated rubber 62 as an example of a seismic isolation support (isolator) that supports the upper structure 20, and a lead damper (hysteretic damping damper) 64 as an example of a damping means that absorbs vibration energy. ,have.

  Similarly, a laminated rubber 62 as an example of a seismic isolation support (isolator) that supports the lower structure 10 and a lead damper (an example of a damping means that absorbs vibration energy) are also provided in the base isolation layer 102. And a seismic isolation device 60 having a type seismic damper 54. The seismic isolation device 60 is provided on a base such as a seismic isolation pit (not shown).

  Further, the response acceleration α2 (see FIG. 1B) of the uppermost layer 22 of the upper structure 20 is the same as the response acceleration α1 (see FIG. 1B) of the uppermost layer 12 of the lower structure 10. As described above, various specifications of each seismic isolation device 60 provided in the intermediate seismic isolation layer 50 and the basic seismic isolation layer 102 are set. An example of the specification setting method (calculation method) will be described later.

[Action and effect]
Next, the operation and effect of this embodiment will be described.

First, an intermediate seismic isolation structure as a comparative example to which the present invention is not applied will be described.
An intermediate seismic isolation structure 900 of a comparative example shown in FIG. 11 has a lower structure portion 10 and an upper structure portion 20, and an intermediate seismic isolation layer 50 is provided between the lower structure portion 10 and the upper structure portion 20. It has been. However, the base seismic isolation layer 102 (FIG. 1A) is not provided between the lower structure portion 10 and the ground 800. Moreover, the intermediate seismic isolation structure 900 of the comparative example makes the natural period longer, thereby avoiding resonance with the strong short-period ground motion during an earthquake and avoiding intense shaking.

  In such an intermediate seismic isolation structure 900, a phenomenon is known in which the response acceleration α3 of the uppermost layer 12 of the lower structure portion 10 (hierarchy immediately below the intermediate seismic isolation layer 50) locally increases (FIG. 11 ( See B)). Therefore, the response displacement (swing width) of the uppermost layer 12 of the lower structure portion 10 at the time of the earthquake becomes large, and the habitability at the time of the earthquake is not sufficiently ensured.

  In addition, when the upper structure part 20 vibrates, when the uppermost layer 12 of the lower structure part 10 is pulled via the seismic isolation device 60, the response acceleration of the uppermost layer 12 of the lower structure part 10 is amplified and locally increased. Conceivable.

  Therefore, in the intermediate seismic isolation structure 100 of this embodiment shown in FIG. 1 (A), by providing the base isolation layer 102 in addition to the intermediate isolation layer 50, the intermediate isolation structure 100 from the ground 800 during an earthquake is provided. The response acceleration input to the (lower structure unit 10) is reduced. Thereby, the vibration of the lower structure part 10 is reduced, and as a result, the response acceleration of the uppermost layer 12 of the lower structure part 10 is reduced. That is, the response displacement (swing width) of the uppermost layer 12 of the lower structure 10 at the time of the earthquake is smaller than that of the intermediate seismic isolation structure 900 (see FIG. 11) of the comparative example, and the habitability at the time of the earthquake is reduced. improves.

  Further, as shown in FIG. 1B, in the present embodiment, the response acceleration α2 of the uppermost layer 22 of the upper structure portion 20 and the uppermost layer 12 of the lower structure portion 10 are the same as the response acceleration α1. Various specifications of each seismic isolation device 60 provided in the intermediate seismic isolation layer 50 and the basic seismic isolation layer 102 are set. Therefore, the response acceleration of both the uppermost layer 22 of the upper structure part 20 and the uppermost layer 12 of the lower structure part 10 is reduced in a balanced manner, thereby improving both habitability (both habitability is ensured). ).

  Moreover, since the seismic isolation displacement amounts of the intermediate isolation layer 50 and the basic isolation layer 102 are the same or substantially the same, they are arranged in the intermediate isolation layer 50 and the basic isolation layer 102. It is easy to design equipment such as various pipes and elevators.

(Method of calculation)
Next, an example of a setting method (calculation method) of specifications of each seismic isolation device 60 provided in the intermediate seismic isolation layer 50 and the basic seismic isolation layer 102 of the intermediate seismic isolation structure 100 described above will be described.

  As shown in FIG. 9, the behavior of the lower structure portion 10 and the upper structure portion 20 in the intermediate seismic isolation structure 100 is replaced with an equivalent two-mass structure model.

Incidentally, the mass of the lower structure portion 10 and m _1, the mass of the upper structure portion 20 and m _2, the rigidity of the basic isolation layer and k1, the rigidity of the intermediate isolation layer 50 and k2. In addition, the amount of ground motion displacement at the time of the earthquake is y ₀ , the amount of interlayer deformation of the base seismic isolation layer 102 (the relative movement amount of the ground 800 and the lower structure 10) is δ _1, and the amount of interlayer deformation of the intermediate seismic isolation layer 50 (relative moving amount of the lower structure portion 10 and the upper structure part 20) and [delta] _2. Further, it is assumed that the upper structure portion 20 and the lower structure portion 10 are rigid bodies.

The equation of motion of the non-damping system using the interlayer deformation amounts δ ₁ and δ ₂ as variables can be expressed as [Equation 1] below.

Here, the eigenvalue of a certain mode is λ (= ω ² )
age,
Change the mode form (corresponding to the interlayer mode) to {du} = {du ₂ du ₂ } ^T
If so, the following equation [Equation 2] is established.

  Furthermore, the following determinant [Formula 3]

Is expressed as [Equation 4] below.

here,
ω ₁ is the natural circular frequency of the lower structure 10 in the non-damping system 1-mass model when the mass of the lower structure 10 is m ₁ and the rigidity of the base seismic isolation layer 102 is k ₁ ,

ω ₂ is the natural circular frequency of the upper structure 20 in the non-damping system 1-mass model when the mass of the upper structure 20 is m ₂ and the rigidity of the intermediate seismic isolation layer 50 is k ₂ ,

γ is a mass ratio (m ₂ = m ₁ ) between the upper structure portion 20 and the lower structure portion 10.

  From [Equation 4], the following relationships (1) to (4) are derived.

(1) When ω ₁ , ω ₂ , and γ are known, the following [Equation 5] is obtained.

(2) When ω ₁ , ω ₂ , and λ are known, the following [Equation 6] is obtained.

(3) When ω ₂ , λ, and γ are known, the following [Equation 7] is obtained.

(4) When ω ₁ , ω ₂ , and λ are known, the following [Equation 8] is obtained.

  Regarding the mode shape (corresponding to the interlayer mode), the following [Equation 9] or [Equation 10] is established.

  Here, the response displacements of the upper structure portion 20 and the lower structure portion 10 are controlled in a balanced manner, that is, the response acceleration α2 of the uppermost layer 22 of the upper structure portion 20 and the response acceleration α1 of the uppermost layer 12 of the lower structure portion 10 are the same. Therefore, assuming that the interlayer response of the primary mode that is dominant in the displacement response is the same in the intermediate isolation layer 50 and the basic isolation layer 102, the relationship between the mass ratio and the displacement Is considered.

From the condition that the interlayer response of the primary mode is the same in the intermediate isolation layer 50 and the basic isolation layer 102, the primary mode form (corresponding to the interlayer mode) is {du} = {1 1} ^T
It can be expressed.

By substituting this mode form into [Equation 9], the following [Equation 11] relational expression regarding the eigenvalues λ ₁ and ω _{2 of the} primary mode is obtained.

Further, γ and λ are known, the omega _2, when applying the relationship [number 11] above, omega ₁ from the [Equation 7] can be expressed as the following Equation 12].

  Then, by using these [Equation 11] and [Equation 12], a non-attenuating two-mass model is created in which the interlayer response in the first-order mode is equal between the intermediate isolation layer 50 and the basic isolation layer 102. Can do.

Next, the maximum value of the stimulation function in the first-order mode is obtained. When the primary mode shape is rewritten to the shape of relative response to the ground (ground) 30,
{U} = {2 1} ^T
It becomes.

Therefore, when the maximum value β ₁ u ₂ of the first-order mode stimulation function with respect to the ground motion acceleration is obtained, it can be expressed as the following [Equation 13].

Here, the maximum value β ₁ u ₂ is a monotonically decreasing function with the mass ratio γ taking values from 1 to 2 as variables. Then, assuming that the assumed range of the actual mass ratio γ in the design is 0.2 to 5.0 (the assumed range in the actual design), the maximum value β ₁ u ₂ is 1.56 to 1.5 from the graph of FIG. The value is 1.08.

  Therefore, for example, when the mass ratio γ = 0.2, the stimulation function of the upper structure portion 20 (upper mass point) is 1.56, and the stimulation function of the lower structure portion 10 (lower mass point) is 0.78. This is based on the assumption that the amount of displacement of the intermediate seismic isolation layer 50 of the intermediate seismic isolation structure 900 (see FIG. 11A) that does not have the basic base isolation layer 102 having the same mass is 1.0. In this case, in the intermediate seismic isolation structure 100 of the present embodiment having the mass ratio γ = 0.2 (see FIG. 1A), the seismic isolation displacements of the intermediate isolation layer 50 and the basic isolation layer 102 are 0 respectively. .78. This relationship applies to response acceleration in a broad sense.

[Modification]
Next, a modification of this embodiment will be described.

(First modification)
In the intermediate seismic isolation structure 110 of the first modification shown in FIG. 2, the upper structure portion 24 is larger than the lower structure portion 14, and the mass m ₂ of the upper structure portion 24 is heavier than the mass m ₁ of the lower structure portion 14. .

  Further, the upper base layer 26 of the upper structure portion 24 and the uppermost layer 16 of the lower structure portion 14 are provided in the intermediate base isolation layer 50 and the base base isolation layer 102 so that the response acceleration α1 is the same. Various specifications of each seismic isolation device 60 are set.

  When the upper structure portion 24 is thus large and heavy, the response acceleration α2 of the uppermost layer 26 of the upper structure portion 24 may be larger than that of the uppermost layer 16 of the lower structure portion 14. That is, the response displacement (swing width) of the uppermost layer 26 of the upper structure portion 24 at the time of an earthquake becomes large, and there may be a case where sufficient comfort is not ensured at the time of the earthquake.

  However, similarly to the first embodiment, in the intermediate seismic isolation structure 110 of the first modified example, by providing the base isolation layer 102 in addition to the intermediate isolation layer 50, the intermediate isolation structure from the ground 800 at the time of the earthquake. The response acceleration input to the object 110 (lower structure part 14) is reduced. Thereby, the response acceleration input to the upper structure portion 24 is reduced, and as a result, the response acceleration α2 of the uppermost layer 26 of the upper structure portion 24 is reduced. Therefore, the response displacement (swing width) of the uppermost layer 26 of the upper structure portion 24 at the time of the earthquake improves the comfortability at the time of the earthquake as compared with the case where the base seismic isolation layer 102 is not provided.

  Similarly to the first embodiment, the intermediate seismic isolation layer 50 and the foundation are set so that the response acceleration α2 of the uppermost layer 22 of the upper structure portion 20 and the uppermost layer 16 of the lower structure portion 14 and the response acceleration α1 are the same. Various specifications of each seismic isolation device 60 provided in the seismic isolation layer 102 are set. Therefore, the response acceleration of both the uppermost layer 26 of the upper structure part 24 and the uppermost layer 16 of the lower structure part 14 is reduced in a balanced manner, so that both habitability is improved (both habitability is ensured). ).

(Second modification)
The intermediate seismic isolation structure 120 of the second modification shown in FIG. 3 is provided with a middle structure portion 30 between the lower structure portion 14 and the upper structure portion 20, and between the upper structure portion 20 and the middle structure portion 30. An intermediate seismic isolation layer 50 is provided, and an intermediate seismic isolation layer 104 is provided between the middle structure portion 30 and the lower structure portion 14.

  Further, each of the isolations provided in the intermediate isolation layer 50 and the intermediate isolation layer 104 so that the response acceleration of the uppermost layer 26 of the upper structure portion 24 and the response acceleration of the uppermost layer 32 of the middle structure portion 30 are the same. Various specifications of the seismic device 60 are set.

  In this modification, the middle structure portion 30 corresponds to the lower structure portion in the claims.

  Further, similarly to the first embodiment and the modified example, in the intermediate seismic isolation structure 120 of the present modified example, in addition to the intermediate seismic isolation layer 50 (or the intermediate seismic isolation layer 104), the intermediate seismic isolation layer 104 (or the intermediate seismic isolation layer). By providing the seismic layer 50), the response acceleration input to the intermediate seismic isolation structure 120 is reduced. As a result, the response acceleration of the uppermost layer 26 of the upper structure portion 24 and the response acceleration of the uppermost layer 32 of the middle structure portion 30 are reduced.

(Third modification)
The intermediate seismic isolation structure 130 of the third modification shown in FIG. 4 is provided with a middle structure portion 34 between the lower structure portion 14 and the upper structure portion 20. Further, an intermediate seismic isolation layer 50 is provided between the upper structure portion 20 and the middle structure portion 34, and an intermediate seismic isolation layer 104 is provided between the middle structure portion 34 and the lower structure portion 14. The base isolation layer 102 is provided between the ground and the ground 800.

  Further, the intermediate seismic isolation layer 50 is set so that the response acceleration of the uppermost layer 22 of the upper structure portion 20, the response acceleration of the uppermost layer 36 of the middle structure portion 34, and the response acceleration of the uppermost layer 16 of the lower structure portion 14 are the same. Various specifications of each seismic isolation device 60 provided in the intermediate seismic isolation layer 104 and the basic seismic isolation layer 102 are set.

  In this modification, the middle structure portion 34 corresponds to the lower structure portion in the claims for the upper structure portion 20, and the middle structure portion 34 in the claims for the lower structure portion 14. Corresponds to the upper structure.

  Similar to the above embodiment and the modified example, in the intermediate seismic isolation structure 130 of the present modified example, in addition to the intermediate seismic isolation layer 50 (or the intermediate seismic isolation layer 104), the intermediate seismic isolation layer 104 (or the intermediate seismic isolation layer 50). ) And the base seismic isolation layer 102, the response acceleration input to the intermediate seismic isolation structure 130 is reduced. Thereby, the response acceleration of the uppermost layer 22 of the upper structure portion 20, the response acceleration of the uppermost layer 36 of the middle structure portion 34, and the response acceleration of the uppermost layer 16 of the lower structure portion 14 are reduced.

(Other variations)
An intermediate seismic isolation structure having another structure may be used. For example, structures such as the fourth to seventh modifications shown in FIGS. 5A to 5D may be used.

  The intermediate seismic isolation structure 140 of the fourth modified example of FIG. 5A is a structure in which the upper structure portion 40 is smaller than the lower structure portion 10 in a plan view and is set back.

  The intermediate seismic isolation structure 150 of the fifth modified example in FIG. 5B has a structure in which the upper structure portion 42 is overhanged larger than the lower structure portion 10 in plan view.

  The intermediate seismic isolation structure 160 of the sixth modified example in FIG. 5C has a step between the upper structure portion 44 and the lower structure portion 45 in a side view, and the intermediate seismic isolation layer 55 is also in accordance therewith. It is a structure with steps.

  The intermediate seismic isolation structure 170 of the seventh modified example in FIG. 5D has a structure in which the upper structure portion 46 and the lower structure portion 47 are each in a parallelogram shape inclined obliquely in a side view.

  Also, in the fourth to seventh modifications, the intermediate seismic isolation layer 104 may be provided instead of the basic seismic isolation layer 102 as in the second modification, or the basic seismic isolation as in the third modification. The structure in which both the layer 102 and the intermediate seismic isolation layer 104 are provided may be used.

  The key is to reduce the second acceleration so as to reduce the response acceleration of the uppermost layer of the lower structure part of the intermediate seismic isolation structure and the uppermost layer of the upper structure part (or at least the higher response acceleration). An earthquake layer (intermediate base isolation layer or basic base isolation layer) may be provided.

<Second embodiment>
Next, an intermediate seismic isolation structure according to the second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st embodiment, and the overlapping description is abbreviate | omitted.

[Construction]
As shown in FIG. 6, the intermediate seismic isolation structure 200 is provided with an intermediate seismic isolation layer 50 between the lower structure portion 10 and the upper structure portion 20. The intermediate seismic isolation layer 50 is provided with a seismic isolation device 60 having a laminated rubber 62 and a lead damper 64 that support the upper structure portion 20.

  A plurality of vibration damping devices 70 are provided on the uppermost layer 12 of the lower structure portion 10 (a layer directly below the intermediate seismic isolation layer 50). The damping device 70 may be any type, but in the present embodiment, structural members such as upper and lower slabs and beams of the uppermost layer 12 are connected via a damper 72 so that the vibration can be reduced by seismic motion. This is an interlayer damper type damping device 70 that absorbs energy by the damper 72 when the upper layer 12 is deformed.

[Action and effect]
Next, the operation and effect of this embodiment will be described.

  As described in the first embodiment, in the intermediate seismic isolation structure 900 of the comparative example shown in FIG. 11, the response acceleration of the uppermost layer 12 of the lower structure portion 10 (the layer immediately below the intermediate seismic isolation layer 50) is amplified. A phenomenon of locally increasing is known. Therefore, the response displacement (swing width) of the uppermost layer 12 of the lower structure portion 10 at the time of the earthquake becomes large, and the habitability at the time of the earthquake is not sufficiently ensured.

  Therefore, in the intermediate seismic isolation structure 200 of the present embodiment, the response acceleration of the uppermost layer 12 of the lower structure unit 10 is reduced by providing the vibration damping device 70 on the uppermost layer 12 of the lower structure unit 10. Therefore, the response displacement (swing width) of the uppermost layer 12 of the lower structure 10 at the time of the earthquake is smaller than that of the intermediate seismic isolation structure 900 (see FIG. 11) of the comparative example, and the habitability at the time of the earthquake is reduced. improves.

[Modification]
Next, a modification of this embodiment will be described.

  In the intermediate seismic isolation structure 210 of the modification shown in FIG. 7, the upper structure portion 24 is larger than the lower structure portion 14, and the mass m2 of the upper structure portion 24 is heavier than the mass m1 of the lower structure portion 14.

  As described in the first embodiment, the response acceleration of the uppermost layer 26 of the upper structure portion 24 may be larger than that of the uppermost layer 16 of the lower structure portion 14. That is, the response displacement (swing width) of the uppermost layer 26 of the upper structure portion 24 at the time of an earthquake becomes large, and there may be a case where sufficient comfort is not ensured at the time of the earthquake.

  Therefore, in the intermediate seismic isolation structure 210 of the first modified example, the vibration damping device 70 is provided in the uppermost layer 26 of the upper structure portion 24 to reduce the response acceleration of the uppermost layer 26 of the upper structure portion 24. Therefore, the response displacement (swing width) of the uppermost layer 26 of the upper structure portion 24 at the time of the earthquake is reduced, and the habitability at the time of the earthquake is improved.

(Other variations)
In the intermediate seismic isolation structure 210 of the modified example of FIG. 7, the vibration damping device 70 is provided in the uppermost layer 26 of the upper structure portion 24, but the vibration damping device 70 is also provided in the uppermost layer 16 of the lower structure portion 14. May be. Moreover, you may provide the damping device 70 also in the uppermost layer 22 of the upper structure part 20 of the intermediate seismic isolation structure 200 of FIG. In other words, the damping device 70 may be provided on both the uppermost layers 22 and 26 of the upper structure portions 20 and 24 of the intermediate seismic isolation structures 200 and 210 and the uppermost layers 12 and 16 of the lower structure portions 10 and 14.

  In addition, the intermediate seismic isolation structure having the basic seismic isolation layer 102 in each modification of the first embodiment shown in FIG. 5 is damped to at least one of the uppermost layer of the upper structure portion and the uppermost layer of the upper structure portion. An apparatus may be provided.

  In short, a vibration damping device may be provided on at least one of the uppermost layer of the lower structure portion of the intermediate seismic isolation structure and the uppermost layer of the upper structure portion (or at least the higher response acceleration).

<Third embodiment>
Next, an intermediate seismic isolation structure according to the third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st embodiment and 2nd embodiment, and the overlapping description is abbreviate | omitted.

[Construction]
As shown in FIG. 8, the intermediate seismic isolation structure 300 includes a lower structure portion 10 and an upper structure portion 20, and an intermediate seismic isolation layer 50 is provided between the lower structure portion 10 and the upper structure portion 20. It has been. In addition, a base seismic isolation layer 102 is provided between the lower structure 10 and the ground 800. Furthermore, a vibration damping device 70 is provided on the uppermost layer 12 of the lower structure portion 10 (just below the intermediate seismic isolation layer 50).

  In the present embodiment, the intermediate seismic isolation layer 50 and the basic seismic isolation layer 102 are arranged so that the response acceleration of the uppermost layer 22 of the upper structure portion 20 and the uppermost layer 12 of the lower structure portion 10 are the same. Each specification of the provided seismic isolation apparatus 60 is set.

[Action and effect]
Next, functions and effects of the present embodiment will be described.

  In the intermediate seismic isolation structure 300 of the present embodiment, by providing the base seismic isolation layer 102 in addition to the intermediate seismic isolation layer 50, the earthquake is input from the ground 800 to the intermediate seismic isolation structure 100 (lower structure unit 10) during an earthquake. Response acceleration is reduced. Furthermore, the response acceleration of the uppermost layer 12 of the lower structure unit 10 is reduced by providing the vibration damping device 70 on the uppermost layer 12 of the lower structure unit 10.

  Therefore, the response acceleration of the uppermost layer 12 of the lower structure unit 10 is effectively reduced. That is, the response displacement (swing width) of the uppermost layer 12 of the lower structure 10 at the time of the earthquake is smaller than that of the intermediate seismic isolation structure 900 (see FIG. 11) of the comparative example, and the habitability at the time of the earthquake is reduced. Effectively improve.

  Furthermore, in the present embodiment, the intermediate seismic isolation layer 50 and the basic seismic isolation layer 102 are arranged so that the response acceleration of the uppermost layer 22 of the upper structure portion 20 and the uppermost layer 12 of the lower structure portion 10 are the same. Each specification of the provided seismic isolation apparatus 60 is set. Therefore, the response acceleration of both the uppermost layer 22 of the upper structure part 20 and the uppermost layer 12 of the lower structure part 10 is reduced in a balanced manner, thereby improving both habitability (both habitability is ensured). ).

[Modification]
Next, a modification of this embodiment will be described.

  In the present embodiment, the vibration damping device 70 is provided on the uppermost layer 12 of the lower structure portion 10, but the vibration damping device 70 may be provided on the uppermost layer 22 of the upper structure portion 20. Furthermore, the vibration damping device 70 may be provided on both the uppermost layer 22 of the upper structure portion 20 and the uppermost layer 12 of the lower structure portion 10.

  In each modification of the first embodiment, the damping device 70 may be provided on at least one of the uppermost layer of the upper structure portion and the uppermost layer of the lower structure portion.

  In the intermediate seismic isolation structure 130 of the third modification shown in FIG. 4 of the first embodiment, at least one of the uppermost layer of the lower structure portion, the uppermost layer of the upper structure portion, and the uppermost layer of the middle structure portion. It is only necessary to have a vibration control device

<Others>
The present invention is not limited to the above embodiment.

  The intermediate seismic isolation structure to which the present invention is applied can be applied not only to new construction, but also to repair of existing structures (seismic repair). Existing structures in the case of renovation (earthquake retrofitting) can be applied to structures with intermediate seismic isolation layers, structures with basic seismic isolation layers, and structures without seismic isolation layers. Furthermore, the present invention can also be applied to a case where a seismic isolation layer is provided on an existing structure and an upper structure portion is extended. It can also be applied to intermediate seismic isolation structures with three or more intermediate isolation layers. In short, the present invention can be applied to all intermediate isolation structures having one or more intermediate isolation layers.

  In addition, the present invention only needs to include response acceleration reduction means (a vibration control device, a seismic isolation layer, or the like) that reduces response acceleration of at least one of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion. Response acceleration reduction means (vibration control device, seismic isolation layer, etc.) should be provided so as to reduce the response acceleration of the uppermost layer of the uppermost layer of the lower structure and the uppermost layer of the upper structure, which has the larger response acceleration. Is desirable.

  It is desirable to provide response acceleration reducing means so that the response acceleration of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion are the same. Alternatively, it is desirable that the specifications of the second seismic isolation layer and the damping device are set so that the response accelerations of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion are the same.

  Further, the above-described plurality of embodiments and modification examples can be implemented in combination as appropriate. Furthermore, it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 10 Lower structure part 12 Top layer 14 Lower structure part 16 Top layer 20 Upper structure part 22 Top layer 24 Upper structure part 26 Top layer 30 Middle structure part (upper structure part, lower structure part)
32 Uppermost layer 34 Middle structure part (upper structure part, lower structure part)
36 uppermost layer 40 upper structure part 42 upper structure part 44 upper structure part 45 lower structure part 46 upper structure part 47 lower structure part 50 middle isolation layer (first isolation layer, second isolation layer))
60 Seismic isolation device (response acceleration reduction means)
70 Damping device (response acceleration reduction means)
100 Intermediate seismic isolation structure 102 Base seismic isolation layer (second seismic isolation layer)
104 Middle base isolation layer (first base isolation layer, second base isolation layer)
110 Intermediate isolation structure 120 Intermediate isolation structure 130 Intermediate isolation structure 140 Intermediate isolation structure 150 Intermediate isolation structure 160 Intermediate isolation structure 170 Intermediate isolation structure 200 Intermediate isolation structure 210 Intermediate Seismic isolation structure 300 Intermediate seismic isolation structure

Claims (3)

A first seismic isolation layer provided between the lower structure and the upper structure;
Response acceleration reducing means for reducing response acceleration of at least one of the uppermost layer of the lower structure part and the uppermost layer of the upper structure part;
A structure comprising The response acceleration reducing means includes a vibration damping device provided on at least one of the uppermost layer of the lower structure portion and the uppermost layer of the upper structure portion.
The intermediate seismic isolation structure according to claim 1. The response acceleration reducing means has a second seismic isolation layer provided in a layer other than the first seismic isolation layer,
The intermediate seismic isolation structure according to claim 1 or claim 2.