JP7035670B2 - How to design a seismic isolation structure - Google Patents

Description

The present invention relates to a method for designing a seismic isolation structure.

In recent years, the response displacement of the seismic isolation device tends to increase due to long-period and long-term seismic motions and seismic motions containing pulse components. Therefore, in the seismic isolation structure, a retaining wall (wall part) is provided in the lower structure below the upper structure, and the collision of the upper structure with the retaining wall is used as a fail-safe mechanism (displacement control mechanism) for unexpected input. Is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-77229

In order to efficiently dissipate the energy generated by the retaining wall collision to the back ground and maintain the soundness of the superstructure, the position where the deformation of the retaining wall and the back ground is maximized (specifically, the length of the retaining wall). It is desirable to collide at the center of the retaining wall).

However, at the same time that the superstructure is displaced horizontally with respect to the substructure, it may be rotationally deformed in the horizontal plane. In this case, the superstructure may collide with the end of the retaining wall (a portion having high rigidity), and the energy generated by the collision may not be efficiently dissipated.

The present invention has been made in view of such a problem, and an object of the present invention is to efficiently dissipate collision energy.

In order to achieve such an object, the method for designing a seismic isolation structure of the present invention is an upper structure having an outer surface along a vertical direction and a first horizontal direction, and a lower structure below the upper structure, and the upper part thereof. Between the lower structure having a wall portion erected in parallel with the outer surface at a predetermined distance in the second horizontal direction orthogonal to the first horizontal direction from the outer surface of the structure, and between the upper structure and the lower structure. In the seismic isolation structure provided with the seismic isolation mechanism provided in the above, a method for designing a seismic isolation structure in which a cushioning material is provided on the side surface of the wall portion facing the outer surface of the upper structure, and an earthquake with a maximum seismic motion. A calculation step for calculating the first horizontal deformation amount of the upper structure, the second horizontal deformation amount of the upper structure, and the rotation angle in the horizontal plane with respect to the lower structure, and the above-mentioned A cushioning material setting step for temporarily setting the material and three-dimensional shape of the cushioning material, and when the superstructure is displaced by the first deformation amount, the second deformation amount, and the rotation angle, the outer surface is the wall portion. A first position calculation step for obtaining the first position of the cushioning material in the first horizontal direction when the cushioning material is in contact with the cushioning material at the same time, and the first position of the wall portion of the cushioning material rather than the first position. A confirmation step to confirm that the superstructure does not collide with the wall due to deformation of the cushioning material even if the maximum seismic motion occurs by approaching the end in the horizontal direction, and the superstructure collides with the wall. It is characterized by having a cushioning material design step for installing the cushioning material having the temporarily set material and shape at a second position confirmed not to be used.
According to such a seismic isolation structure design method, it is possible to prevent the superstructure from rotating with respect to the substructure and colliding with the end portion of the wall portion, and the collision energy can be efficiently dissipated.

In the design method of the seismic isolation structure, the second position is in the first horizontal direction of the wall portion rather than the contact position between the outer surface of the superstructure and the wall portion at the time of the first position. Near the center,
Is desirable.
According to the design method of such a seismic isolation structure, it is possible to collide with a place where the wall portion is greatly deformed, and the collision energy can be further dissipated.

In the design method of the seismic isolation structure, the relationship between the rotation angle and the horizontal rigidity of the cushioning material is obtained in advance, and confirmation that the upper structure does not collide with the wall portion is determined by the rotation angle. It is desirable to do this based on the horizontal stiffness of the corresponding cushioning material.
According to such a seismic isolation structure design method, it is possible to easily confirm the presence or absence of a collision between the superstructure and the wall portion.

In the method of designing the seismic isolation structure, if it cannot be confirmed in the confirmation step that the superstructure does not collide with the wall portion, the material and shape of the cushioning material may be reviewed. Further, the position of the cushioning material may be reviewed.
According to the design method of such a seismic isolation structure, the cushioning material can be made to function properly.

In the method of designing the seismic isolation structure, before the cushioning material design step, the difference between the predetermined distance and the thickness of the cushioning material in the second horizontal direction is obtained from the design limit displacement of the seismic isolation mechanism. It is desirable to have more design confirmation steps to confirm that they are large.
According to the design method of the seismic isolation structure, it is possible to prevent the retaining wall collision within the design range.

In the design method of such a seismic isolation structure, it is desirable that the surface of the wall portion on the opposite side to the side surface is in contact with the ground.
According to the design method of such a seismic isolation structure, the collision energy can be more dissipated.

The method for designing such a seismic isolation structure further includes a soundness confirmation step for confirming that the allowable energy of the superstructure at the time of design is larger than the residual energy of the superstructure after a collision. desirable.
According to such a seismic isolation structure design method, it is possible to satisfy the seismic performance determined at the time of design.

According to the present invention, the collision energy can be efficiently dissipated.

1A is a schematic plan view showing the configuration of the seismic isolation structure of the present embodiment, and FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A. It is a flow chart which shows an example of the design method of the seismic isolation structure in this embodiment. FIG. 3A is a diagram showing a state in which the superstructure 2 collides with the cushioning material 20 at a rotation angle θ = 0 (zero) degrees, and FIG. 3B shows a state in which the superstructure 2 collides with the cushioning material 20 at a rotation angle θ = θ _i . It is a figure which shows the state at the moment of a collision. 4A to 4C are explanatory views of an example of a horizontal rigidity test method with respect to a collision angle. 4A is a diagram when the collision angle θ = 0 (zero) degrees, FIG. 4B is a diagram when the collision angle θ = θ ₁ , and FIG. 4C is a diagram when the collision angle θ = θ ₂ (> θ ₁ ). It is a figure which shows an example of the test result of FIG. It is a figure which shows an example of the state which the superstructure 2 is horizontally displaced and rotated with respect to a lower structure 4. 7A and 7B are explanatory views showing a position setting method. FIG. 8A is a conceptual diagram showing a deformed state of the wall portion 41 due to a collision with the superstructure 2, and FIG. 8B is a model conceptual diagram of collision analysis.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

=== Embodiment ===
<< About the composition of the seismic isolation structure >>
1A is a schematic plan view showing the configuration of the seismic isolation structure of the present embodiment, and FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A. In the following description, the direction is determined as shown in FIGS. 1A and 1B. That is, one of the two orthogonal directions in the horizontal plane is the X direction (corresponding to the second horizontal direction), and the other is the Y direction (corresponding to the first horizontal direction). Further, the direction orthogonal to the X direction and the Y direction is defined as the Z direction (vertical direction).

The seismic isolation structure of the present embodiment includes an upper structure 2, a lower structure 4, and a seismic isolation device 10.

The superstructure 2 is, for example, a structure such as a building, a floor, or a large device. The superstructure 2 of the present embodiment has a rectangular planar shape and has four outer surfaces (outer surfaces 2A, 2B, 2C, 2D).

The outer surface 2A and the outer surface 2C are parallel to the YZ plane (in other words, along the Y and Z directions). Further, the outer surface 2B and the outer surface 2D are parallel to the XZ plane (in other words, along the X direction and the Z direction).

The lower structure 4 is a structure that supports the upper structure 2 and transmits a load to the ground, and is formed below the upper structure 2. As shown in FIG. 1B, a gap S in the Z direction is provided between the upper structure 2 and the lower structure 4.

Further, the lower structure 4 has a retaining wall 40 provided so as to surround the outside of the upper structure 2. As the material of the retaining wall 40, concrete having high elasticity performance (for example, concrete made of ceramic material) and concrete having high damping performance (for example, concrete using high damping rubber as a part of aggregate) are preferable.

The retaining wall 40 of the present embodiment is composed of a wall portion 41, a wall portion 42, a wall portion 43, and a wall portion 44.

The wall portion 41 is erected in parallel with the outer surface 2A at a predetermined distance (clearance) in the X direction from the outer surface 2A of the superstructure 2. The wall portion 42 is erected in parallel with the outer surface 2B at a predetermined distance in the Y direction from the outer surface 2B of the superstructure 2. The wall portion 43 is erected in parallel with the outer surface 2C at a predetermined distance in the X direction from the outer surface 2C of the superstructure 2. The wall portion 42 is erected in parallel with the outer surface 2D at a predetermined distance in the Y direction from the outer surface 2D of the superstructure 2.

Further, as shown in FIGS. 1A and 1B, two cushioning materials 20 are installed on the side surface 41A facing the outer surface 2A of the superstructure 2 of the wall portion 41. The two cushioning materials 20 are provided apart from each other in the y direction so as to sandwich the center of the wall portion 41 in the y direction. The cushioning material 20 is a member for alleviating an impact due to a collision, and is, for example, a resin (for example, polypropylene) honeycomb structure plate or a rubber fender.

Similarly, two cushioning materials 20 are installed on the side surface of the wall portion 42 facing the superstructure 2, the side surface of the wall portion 43, and the side surface of the wall portion 44. That is, two cushioning materials 20 are installed on each side of the retaining wall 40. Since the configuration of each wall portion is the same, the following description will be made using the wall portion 41 (and the cushioning material 20).

The side surface 41B opposite to the side surface 41A of the wall portion 41 is in contact with the back ground 50. As the background ground 50, a ground having high damping performance such as clayey ground is desirable.

As shown in FIG. 1B, the seismic isolation device 10 (corresponding to the seismic isolation mechanism) is interposed in the gap S between the upper structure 2 and the lower structure 4. In the following description, the portion (gap S) where the seismic isolation device 10 is provided is also referred to as a seismic isolation layer. In the present embodiment, as shown in FIG. 1A, four seismic isolation devices 10 (one at each corner of the superstructure 2) are arranged in the seismic isolation layer. Then, each seismic isolation device 10 shares and supports the weight of the superstructure 2 at each position. The number and location of the seismic isolation devices 10 are not limited to this.

As shown in FIG. 1B, the seismic isolation device 10 of the present embodiment has laminated rubber 12 (for example, a columnar elastic body formed by alternately laminating circular thin steel plates 12a and rubber layers 12b vertically). It is configured to be sandwiched between a pair of upper and lower flange plates (upper flange plate 11, lower flange plate 13). Further, the lower flange plate 13 is fixed to the lower structure 4 by bolts (not shown) or the like, and the upper flange plate 11 is fixed to the upper structure 2 by bolts (not shown) or the like. Then, the seismic isolation device 10 supports the superstructure 2, and the laminated rubber 12 is sheared and deformed in the horizontal direction according to the horizontal force due to the relative displacement between the superstructure 2 and the substructure 4, so that the superstructure 2 is horizontal. Prolongs the vibration cycle (functions as a seismic isolation bearing).

In the seismic isolation structure having the above configuration, when the upper structure 2 collides with the retaining wall 40 (for example, the wall portion 41), the energy generated by the collision is efficiently dissipated to the back ground 50, and the soundness of the upper structure 2 is improved. In order to maintain the wall portion 41, it is desirable that the wall portion 41 collides at a position where the rigidity is small and the deformation of the back ground 50 is maximized. Here, the end portion (end portion in the Y direction) of the wall portion 41 is a corner portion of the retaining wall 40, and has higher rigidity (difficult to deform) than the central portion. Therefore, it is desirable to collide at a position close to the center of the wall portion 41. However, the superstructure 2 may be rotationally deformed not only in the horizontal direction (X direction, Y direction) but also in the horizontal plane, and when such rotational deformation occurs, it collides with the end portion of the wall portion 41. It will be easier.

Therefore, in the present embodiment, by setting the material and position of the cushioning material 20 installed on the wall portion 41, the collision energy is collided at a position close to the center of the wall portion 41 to secure the effect of dissipating the collision energy to the ground ground 50 and the like. I try to do it.

<< About the design method >>
FIG. 2 is a flow chart showing an example of a method for designing a seismic isolation structure according to the present embodiment.

First, the basic design of the seismic isolation structure shown in FIG. 1 (design of a general seismic isolation building) is performed (S100). For example, the shapes of the superstructure 2 and the substructure 4 (retaining wall 40), the design limit displacement (δd) of the seismic isolation layer, the clearance (C), and the like are designed.

Next, the maximum seismic motion that is not considered in the normal design is input to the response analysis model, and the deformation amount (δ) and rotation angle (θ) of the superstructure 2 with respect to the substructure 4 due to the maximum seismic motion exceeding the assumption are calculated (S101: Corresponds to the calculation step).

Next, the material and the three-dimensional shape of the cushioning material 20 are temporarily set (S102: corresponding to the cushioning material setting step).

In the present embodiment, the cushioning material 20 is a rectangular parallelepiped having a length (b), a width (d), and a thickness (h), and the cross-sectional area of a surface perpendicular to the thickness direction is A (= b × d). Further, the Young's modulus (E) is set according to the material of the material used for the cushioning material 20.

Further, since the horizontal rigidity of the cushioning material 20 differs depending on the rotation angle (collision angle), the horizontal rigidity of the cushioning material 20 with respect to the collision angle is evaluated in advance by an experiment or the like.

FIG. 3A is a diagram showing a state in which the superstructure 2 collides with the cushioning material 20 at a rotation angle θ = 0 (zero) degrees, and FIG. 3B shows a state in which the superstructure 2 collides with the cushioning material 20 at a rotation angle θ = θ _i . It is a figure which shows the state at the moment of a collision.

As shown in FIG. 3A, when the rotation angle θ = 0 (zero) degree, the outer surface 2A of the superstructure 2 comes into contact with the surface of the cushioning material 20 (surface contact). On the other hand, when the rotation angle θ = θ _i , as shown in FIG. 3B, the outer surface 2A of the superstructure 2 comes into contact with the corner portion (end portion) of the cushioning material 20. The deformed shape and horizontal rigidity of the cushioning material 20 differ depending on the difference in the state at the time of collision (difference in rotation angle θ).

4A to 4C are explanatory views of an example of a method for testing the horizontal rigidity with respect to the angle of collision. 4A is a diagram when the collision angle θ = 0 (zero) degrees, FIG. 4B is a diagram when the collision angle θ = θ ₁ , and FIG. 4C is a diagram when the collision angle θ = θ ₂ (> θ ₁ ). The left side of each figure shows the figure before the load P is applied to the cushioning material 20, and the right side shows the figure after the load P is applied to the cushioning material 20 (after the collision).

When the collision angle θ is zero degree, the horizontal rigidity K _h (theoretical value) of the theoretical cushioning material 20 is
K _h = EA / h ・ ・ ・ (1)
Will be.

In this embodiment, the tests shown in FIGS. 4A to 4C are carried out to obtain the horizontal rigidity K _h when the collision angle changes.

When a load P is applied to the surface of the cushioning material 20 at a collision angle θ = 0 degrees as shown in FIG. 4A, the cushioning material 20 is deformed as a whole. Assuming that the thickness of the cushioning material 20 changes from h to h ₀ , the horizontal rigidity K _h 0 in this case is
K _h0 = P / (h-h ₀ ) ・ ・ ・ (2)
Will be. The value of the equation (2) is substantially equal to the value (theoretical value) of the equation (1).

When the collision angle θ = θ ₁ , a load P is applied to the corner portion of the cushioning material 20 as shown in FIG. 4B. As a result, the cushioning material 20 is locally deformed to have a thickness of h ₁ . By locally deforming, the thickness h ₁ is smaller than the thickness h ₀ (h ₁ <h ₀ ). The horizontal rigidity K _h1 in this case is
K _h1 = P / (h-h ₁ ) ・ ・ ・ (3)
From h ₁ <h ₀ , the horizontal stiffness K _h1 obtained by the equation (3) is smaller than the horizontal _stiffness K h 0 obtained by the equation (2).

Even when the collision angle θ = θ ₂ , the load P is applied to the corner portion of the cushioning material 20 as shown in FIG. 4C. As a result, the cushioning material 20 is locally deformed to have a thickness of h ₂ (<h ₁ ). The horizontal rigidity K _h2 in this case is
K _h2 = P / (h-h ₂ ) ・ ・ ・ (4)
From h ₂ <h ₁ , the horizontal rigidity K h 2 obtained by the equation (4) is smaller than the horizontal rigidity K _{h 1} obtained by the equation (3).

As described above, the relationship between the collision angle θ and the horizontal rigidity K _h is obtained by changing the magnitude of θ (for example, up to a magnitude of about 5 degrees).

FIG. 5 is a diagram showing an example of the test result of FIG. The horizontal axis of the figure shows the magnitude of the collision angle θ, and the vertical axis represents the magnitude of the horizontal rigidity K _h . As shown in the figure, the horizontal rigidity K _h depends on the collision angle θ, and the horizontal rigidity K _h decreases as the collision angle θ increases. Therefore, it can be said that the larger the collision angle θ, the larger the required horizontal rigidity K _h . In FIG. 5, the relationship between the collision angle θ and the horizontal rigidity K _h is a straight line, but it does not always change linearly. Further, although the vertical and horizontal dimensions (b, d) of the cushioning material 20 are fixed and evaluated here, it is necessary to consider the influence of the sizes of the dimensions b and d.

As described above, the characteristics of the horizontal rigidity of the cushioning material 20 according to the collision angle (rotation angle) θ are confirmed in advance by a test or the like for each material and three-dimensional shape (b, d, h) to be used.

Next, the installation position of the cushioning material 20 is set (S103).

FIG. 6 is a diagram showing an example of a state in which the upper structure 2 is horizontally displaced and rotated with respect to the lower structure 4. Further, FIGS. 7A and 7B are explanatory views showing an example of the position setting method.

In FIG. 6, the state in which the superstructure 2 is displaced δxi in the X direction and δyi in the Y direction is shown by a broken line, and the state in which the superstructure 2 is rotated at a rotation angle θi around the rigid center position J at that time is a one-dot chain line. It is shown by. Note that δxi is the X-direction component of the deformation amount δ of the superstructure 2 due to the maximum seismic motion, and δyi is the Y-direction component of the deformation amount δ. Further, the clearance in the X direction (distance between the superstructure 2 and the wall portion 41) is defined as Cx, and the clearance in the Y direction (distance between the superstructure 2 and the wall portion 42) is defined as Cy. Here, for convenience of explanation, δxi <Cx and δyi <Cy are set.

Further, the distance from the rigid center position J to the corner portion of the upper structure 2 is r, the displacement amount of the corner portion in the x direction after rotation angle θi is Rxi, and the displacement amount in the y direction is Ryi. .. Further, the distance from the end of the wall portion 41 in the Y direction to the cushioning material 20 is defined as α.

From FIG. 6,
Rxi = r × (cosθ _i -cosθ ₀ ) ... (5)
Ryi = r × (sinθ ₀ -sinθ _i ) ... (6)
Ri'= α- (Ryi + Cy-δyi) ... (7)
Ri "= Ri'x tanθi ... (8)
When the relational expression of is established and the superstructure 2 does not collide with the wall portion 41 (however, the contact is included).
h-Ri "≧ 0 ・ ・ ・ (9)
From equation (9)
α≤h / tanθi + r (sinθ ₀ -sinθi) + Cy-δyi ... (10)
or,
h ≧ {α-r (sinθ ₀ -sinθi) -Cy + δyi} tanθi ・ ・ ・ (11)
The relationship is established.

First, with respect to the temporarily set thickness h, when the displacement δxi in the X direction, the displacement δyi in the Y direction, and the rotation angle θi, the outer surface 2A of the superstructure 2 is simultaneously attached to the wall portion 41 and the cushioning material 20. Find the value of α1 at the time of contact. In other words, the position of the cushioning material 20 in the Y direction (corresponding to the first position) is obtained (corresponding to the first position calculation step). Note that α1 is the value of α when the equation (9) becomes an equation.

However, in FIG. 7A, since the required horizontal rigidity K _h of the cushioning material 20 becomes infinite because the superstructure 2 and the wall portion 41 do not collide, the position of the cushioning material 20 is changed from α1 to α2. (See FIG. 7B). That is, the cushioning material 20 is brought closer to the end side of the wall portion 41 in the Y direction. However, since it is desirable that the cushioning material 20 is installed at a position close to the center of the wall portion 41 in the length direction (Y direction), α2 is set at a position as close as possible to α1. As a result, as shown in FIG. 7B, the superstructure 2 is not in contact with the wall portion 41 at the moment when the superstructure 2 collides with the cushioning material 20. Further, θi, δi, and Pi at the moment when the superstructure 2 comes into contact with the cushioning material 20 (state in FIG. 7B) when the position of the cushioning material 20 is changed to α2 are obtained from the analysis results.

Then, from the above-mentioned horizontal rigidity test result (see FIG. 5), the horizontal rigidity K _h θ at the collision angle (rotation angle) θi is obtained, and it is confirmed whether the relationship is as follows.

Pi / K _h θ <δi ・ ・ ・ (12)
When the equation (12) holds, the superstructure 2 does not collide with the wall portion 41. In this way, after the superstructure 2 comes into contact with the cushioning material 20 as shown in FIG. 7B, it is confirmed whether the superstructure 2 is further displaced and does not collide with the wall portion 41 (S104: corresponding to the confirmation step).

If it is determined that a collision occurs (NO in S104), the process returns to step S102 and the design of the set cushioning material 20 is reviewed. That is, the material, shape, or position of the cushioning material 20 is reset. By repeating this flow, the cushioning material 20 can function properly (that is, the superstructure 2 does not collide with the wall portion 41).

When it is determined that there is no collision (YES in S104), the difference between the clearance (C) and the thickness (h) of the cushioning material 20 is larger than the design limit displacement (δd) of the seismic isolation layer (seismic isolation device 10). Confirm that (δd <Ch) (S105: corresponds to the design confirmation step).

When δd ≧ C—h (NO in S105), the superstructure 2 may collide with the retaining wall 40 (cushioning material 20) within the normal design range. Therefore, in this case, the process returns to step S102 to review (reset) the design of the set cushioning material 20.

In the case of δd <C-h (YES in S105), the cushioning material 20 having the temporarily set material and shape is installed at the set position of the wall portion 41 (corresponding to the cushioning material design step), and the superstructure 2 and the wall portion 41 are installed. Collision analysis with (cushioning material 20) is performed (S106).

FIG. 8A is a conceptual diagram showing a deformed state of the wall portion 41 due to a collision with the superstructure 2, and FIG. 8B is a model conceptual diagram of collision analysis. Here, a mass point model with a small degree of freedom is used.

When the wall portion 41 is deformed due to the collision with the superstructure 2 as shown in FIG. 8A, the back ground 50 on the side surface 42b side of the wall portion 41 is pushed by the wall portion 41 (the dark hatched portion in the figure).

The region of the back ground 50 pushed in at this time is taken into consideration in the amount of kinetic energy of the retaining wall as an additional mass effect, as shown in FIG. 8B. Then, the collision analysis can be performed using the mass point system model of FIG. 8B.

In the seismic isolation structure of the present embodiment, since the cushioning material 20 is provided on the wall portion 41 as shown in FIG. 7B, the upper structure 2 is located from the collision position with the wall portion 41 in FIG. 7A (near the center of α1). , It will collide with the wall portion 41 (cushioning material 20) at a position (α2) near the center of the wall portion 41. As a result, the energy due to the collision between the superstructure 2 and the wall portion 41 (cushioning material 20) is likely to be dissipated to the back ground 50.

In addition to the mass point system model, for example, analysis using a three-dimensional FEM having a large degree of freedom may be performed.

Then, it is determined whether or not the design target (seismic performance) set at the time of structural design can be satisfied by this analysis result or the following energy evaluation formula (13) (S107: corresponding to the soundness confirmation step).

_ER < _ED ... (13)
In the formula (13), _ER is the residual energy amount of the superstructure 2 after the collision, the collision energy amount is _EB , the absorbed energy amount of the wall portion 41 is _EW , and the absorbed energy amount of the back ground 50 is E. When _S is set E _R = E _B -E _W -E _S ... (14)
Is.

Further, _ED is the allowable energy amount of the superstructure 2 at the time of design.
By substituting ED with the displacement-load relationship of each member (each layer) of the _{superstructure} 2, the cross-sectional calculation of the member, the interlayer deformation, and the like are evaluated.

If it is determined that the design target is not satisfied (NO in S107), the process returns to step S102 and the design of the cushioning material 20 is reviewed. If it is determined that the design target is satisfied (YES in S107), the design of the seismic isolation structure is completed.

In this embodiment, the design of the seismic isolation structure in consideration of the collision between the superstructure 2 and the wall portion 41 (cushioning material 20) has been described, but other wall portions (wall portion 42, wall portion 43, wall portion) have been described. The same applies to 44).

=== About other embodiments ===
The above embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. It goes without saying that the present invention can be modified and improved without departing from the spirit thereof, and the present invention includes an equivalent thereof. In particular, even the embodiments described below are included in the present invention.

In the above-described embodiment, the seismic isolation device 10 is a laminated rubber type seismic isolation device, but the seismic isolation device 10 is not limited to this. For example, it may be a seismic isolation device for sliding bearings or rolling bearings. Further, a damping device such as a damper may be installed on the seismic isolation layer.

Further, in the above-described embodiment, the material and shape (b, d, h) of the cushioning material 20 are set, and then the installation position of the cushioning material 20 is set, but the order may be reversed. That is, after setting the position of the cushioning material 20, the material and shape of the cushioning material 20 may be set.

Further, in the above-described embodiment, the shape of the cushioning material 20 is a rectangular parallelepiped, but the shape is not limited to this, and other shapes (for example, a cylindrical shape) may be used.

Further, in the above-described embodiment, the outside of the retaining wall 40 (for example, the side surface 41B side of the wall portion 41) is the back ground 50, but it does not have to be the ground. However, if the outside of the retaining wall 40 is made of a material having high damping performance or improved ground, the collision energy can be dissipated more.

2 Superstructure,
2A, 2B, 2C, 2D outer surface,
4 Substructure,
10 Seismic isolation device (seismic isolation mechanism),
11 Upper flange plate,
12 laminated rubber, 12a steel plate, 12b rubber layer,
13 Lower flange plate,
20 cushioning material,
40 retaining wall,
41, 42, 43, 44 wall,
41A side, 41B side,
50 Back ground (ground)

Claims (8)

A superstructure with outer surfaces along the vertical and first horizontal directions,
A wall portion that is a lower structure below the superstructure and is erected in parallel with the outer surface at a predetermined distance in a second horizontal direction orthogonal to the first horizontal direction from the outer surface of the superstructure. With the substructure it has,
A seismic isolation mechanism provided between the superstructure and the substructure,
A method for designing a seismic isolation structure in which a cushioning material is provided on the side surface of the wall portion facing the outer surface of the superstructure.
By seismic response analysis at the maximum seismic motion, the first deformation amount of the superstructure with respect to the substructure in the first horizontal direction, the second deformation amount in the second horizontal direction, and the rotation angle in the horizontal plane are calculated. Calculation steps and
The cushioning material setting step for temporarily setting the material and the three-dimensional shape of the cushioning material, and
When the superstructure is displaced by the first deformation amount, the second deformation amount, and the rotation angle, the first of the cushioning material when the outer surface comes into contact with the wall portion and the cushioning material at the same time. The first position calculation step for finding the first position in the horizontal direction, and
The cushioning material is brought closer to the first horizontal end of the wall portion than the first position, and even if the maximum seismic motion occurs, the upper structure does not collide with the wall portion due to the deformation of the cushioning material. Confirmation steps to confirm that, and
A cushioning material design step for installing the cushioning material having the temporarily set material and shape at a second position where it is confirmed that the superstructure does not collide with the wall portion.
A method of designing a seismic isolation structure characterized by having. The method for designing a seismic isolation structure according to claim 1.
The second position is closer to the center of the wall portion in the first horizontal direction than the contact position between the outer surface of the superstructure and the wall portion at the time of the first position.
How to design a seismic isolation structure The method for designing a seismic isolation structure according to claim 1 or 2.
The relationship between the rotation angle and the horizontal rigidity of the cushioning material has been obtained in advance.
Confirmation that the superstructure does not collide with the wall portion is performed based on the horizontal rigidity of the cushioning material corresponding to the rotation angle.
A method of designing a seismic isolation structure. The method for designing a seismic isolation structure according to any one of claims 1 to 3.
If it cannot be confirmed in the confirmation step that the superstructure does not collide with the wall portion, the material and shape of the cushioning material are reviewed.
A method of designing a seismic isolation structure. The method for designing a seismic isolation structure according to any one of claims 1 to 3.
If it cannot be confirmed in the confirmation step that the superstructure does not collide with the wall portion, the position of the cushioning material is reviewed.
A method of designing a seismic isolation structure. The method for designing a seismic isolation structure according to any one of claims 1 to 5.
Prior to the cushioning material design step, there is further a design confirmation step for confirming that the difference between the predetermined distance and the thickness of the cushioning material in the second horizontal direction is larger than the design limit displacement of the seismic isolation mechanism. ,
A method of designing a seismic isolation structure. The method for designing a seismic isolation structure according to any one of claims 1 to 6.
The surface of the wall portion opposite to the side surface is in contact with the ground.
A method of designing a seismic isolation structure. The method for designing a seismic isolation structure according to any one of claims 1 to 7.
The sanity confirmation step, which confirms that the allowable energy of the superstructure at the time of design is larger than the residual energy of the superstructure after the collision.
A method of designing a seismic isolation structure, which is characterized by having a seismic isolation structure.

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