JP2019100143A - Base isolation structure - Google Patents

Abstract

To provide a base isolation structure which can, even when a relative positional displacement between an upper structure and an under structure in a horizontal direction is huge, prevent them from directly colliding with each other and which can suppress swinging back of an upper structure.SOLUTION: A base isolation structure 100 comprises: an upper structure 10; an under structure 20; and a base isolation device 30 positioned between the upper structure 10 and the under structure 20. The under structure 20 includes a facing wall 22 which faces a part of a side wall 12 of the upper structure 10 and which is separated from the side wall 12. An impact absorption member 40 comprising a foamed resin body 42 is arranged at a position facing the facing wall 22 in the side wall 12, and in addition a space S is provided between the impact absorption member 40 and the facing wall 22. Or, an impact absorption member 40 comprising a foamed resin body 42 is arranged at a position facing the side wall 12 in the facing wall 22, and in addition a space S is provided between the impact absorption member 40 and the side wall 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a seismic isolation structure, and more specifically to a seismic isolation structure including a seismic isolation device, which is excellent in safety even when the seismic isolation structure exhibits excessive displacement in the horizontal direction. .

  As a seismic isolation structure, there is known a seismic isolation structure in which a seismic isolation device is provided which separates an upper structure (for example, a building) and a lower structure (for example, a foundation structure) via an elastic member or the like. For example, rubber (particularly, high damping rubber) is known as the elastic member. In the above-described seismic isolation structure, the lower region of the upper structural body and the lower structural body face each other in a state where a certain clearance (space) is secured. The clearance is not only between the lower surface of the upper structure and the upper surface of the lower structure, but also between the side surface (side wall) of the lower region of the upper structure and the vertical wall surface of the lower structure opposite thereto. Are also provided in the same way. In general, when the lower structure shakes in the horizontal direction with the ground due to an earthquake or the like, the upper structure edged with respect to the lower structure generally has a small amount of transmission of the shake from the lower structure, The said shake is damped by the deformation etc. of the elastic member with which a seismic isolation apparatus is equipped. As an example of the displacement of the elastic member, relative positional displacement in the horizontal direction of the upper structure and the lower structure at the time of the occurrence of an earthquake may be mentioned. By design, it is assumed that the relative positional displacement is within the range of the clearance, so that a collision between the upper structure and the lower structure is avoided.

  However, when the horizontal displacement of the elastic member in the seismic isolation system becomes large due to the occurrence of a large earthquake or the like, or a long period ground motion occurs, the period of ground motion coincides with the natural period of the superstructure and resonates. In the case where the upper structure shakes greatly or the like, the relative positional displacement between the upper structure and the lower structure becomes enormous, and as a result, there is a possibility that the upper structure and the lower structure collide with each other. Such collision may cause damage to the upper structure or the lower structure, which is a problem. In particular, although research on long-period ground motions has been active in recent years, it can not be said that adequate measures have been taken yet, and it is possible not only to newly built buildings but also to existing buildings. The measures are under pressure.

As seismic vibration, a body wave (so-called P wave and S wave) propagated in the ground and a surface wave propagated along the ground surface are known. The surface wave travels to a far distance compared with the body wave, and the attenuation during propagation is gentle, and it is clarified from many studies that the surface wave is strongly amplified in the sedimentary layer of the soft plain of the ground. Therefore, long-period ground motion may occur on land far from the epicenter.
On the other hand, it is known that a building has an inherent period according to the height, and the higher the height of the building, the longer the inherent period. When an earthquake with a period close to the natural period occurs, a resonance phenomenon occurs, and the magnitude of the swing tends to increase as the swing of the building continues.
Therefore, particularly when the superstructure is a tall structure such as a high-rise building, the superstructure tends to have a long natural period, resonates in synchronization with the period of the long period ground motion, and the earthquake at the epicenter Even if it stopped, the shaking continued and it tended to grow. Therefore, measures against long-period ground motions for tall buildings and other tall buildings are very important.

The following seismic isolation structure 500 is proposed as a technique corresponding to the said problem. 5 (a) and 5 (b) will be used to explain the seismic isolation structure 500. FIG. FIG. 5 (a) is a schematic view of the normal state of the seismic isolation structure 500 including the conventional shock absorbing member 530, and FIG. 5 (b) is a diagram when vibration of the seismic isolation structure 500 including the conventional shock absorbing member 530 occurs. FIG.
The conventional seismic isolation structure 500 is provided with a seismic isolation device 540 as shown in FIG. 5A, and at a portion where the building 510 (upper structure) and the retaining wall 522 of the building foundation 550 (lower structure) are opposed. An impact absorbing member 530 formed of rubber is provided on the retaining wall inner surface 520 (see, for example, Patent Document 1 below).
In the seismic isolation structure 500, as shown in FIG. 5 (b), it is planned that the side wall 512 of the building 510 and the shock absorbing member 530 collide when an enormous shaking occurs. This prevents direct collision between the side wall 512 of the building 510 and the retaining wall inner surface 520. The collision between the building 510 and the shock absorbing member 530 causes the shock absorbing member 530 to be compressed and deformed, and the building 510 receives a reaction force from the shock absorbing member 530. As a result, Patent Document 1 describes that the impact generated on the building 510 and the retaining wall 522 due to the collision is mitigated. In Patent Document 1, a high damping rubber is recommended as a rubber that constitutes the shock absorbing member 530.

JP, 2014-77229, A

  However, although the above-described base isolation structure 500 is mainly intended to suppress the shaking of the building 510 at the time of an earthquake, etc., rubber is used as the shock absorbing member 530, so that the building 510 is described below. The problem is that there is a risk of promoting a swing back.

  That is, rubber generally has a large elastic force. Therefore, when the side wall 512 collides with the impact absorbing member 530 which is rubber, the rubber compresses and deforms, and a force (repulsive force) to return the deformation to the original is generated promptly. That is, when rubber is used as the shock absorbing member 530 of the seismic isolation structure 500, the collision force between the building 510 and the shock absorbing member 530 is temporarily received by compression deformation of the rubber, but immediately after that It is converted. As a result, the building 510 that has received the repulsion may be shaken back, which may promote the shaking of the building 510, which is a problem. Arrows in FIG. 5 (b) schematically show the repulsive force of the rubber.

It is known that the high damping rubber is deformed when it is given an impact force, and exhibits a conversion action of converting the energy (deformation energy) which has caused the deformation into thermal energy. However, although the above-mentioned conversion action is remarkably exhibited when the high damping rubber is sheared and deformed, it is small when it is compressed and deformed. Therefore, the compressively deformed high damping rubber can exert a repulsive force close to that of a general rubber.
That is, when vibration in the horizontal direction occurs due to an earthquake or the like, the high damping rubber used as an elastic member in the seismic isolation device undergoes shear deformation to attenuate the vibration and shakes back the building by exerting the conversion function. Suppress. Therefore, it can be said that high damping rubber is suitable as an elastic member in a seismic isolation system.
However, although the high damping rubber used as the shock absorbing member 530 of the seismic isolation structure 500 is compressively deformed by a collision with the building 510 to receive the collision force at one end, it is a part of the collision force like general rubber. Or all may be reduced to repulsive force. Therefore, similarly to general rubber, high damping rubber is also problematic because the building 510 may be shaken back by the repulsive force.

  The present invention has been made in view of the above problems. That is, according to the present invention, even when the relative positional displacement between the upper structure and the lower structure in the horizontal direction is enormous, the direct collision between them is avoided and the swing back of the upper structure is suppressed. It provides a possible seismic isolation structure.

  The seismic isolation structure of the present invention comprises an upper structural body, a lower structural body, and a seismic isolation device positioned between the upper structural body and the lower structural body, and the lower structural body is the upper structure A shock absorbing member is provided, which has a facing wall facing a part of the side wall of the body and separated from the side wall, and provided with a foamed resin body at a position facing the facing wall of the side wall, A space is provided between the impact absorbing member and the opposing wall, or an impact absorbing member including a foamed resin body is provided at a position of the opposing wall facing the side wall, and A space is provided between the shock absorbing member and the side wall.

  In the seismic isolation structure of the present invention, even if the relative displacement between the upper structure and the lower structure in the horizontal direction is enormous, the upper structure and the lower structure are provided with the shock absorbing member in the upper structure. The structure only collides indirectly via the shock absorbing member. Thus, damage to the upper and lower structures during a collision is prevented. Further, the shock absorbing member in the present invention is constituted by using a foamed resin body, and can well absorb the collision force generated by the collision between the shock absorbing member and the lower structure, and can be repelled like rubber. Does not generate force. Therefore, according to the present invention, the swinging back of the upper structure due to the repulsive force of the shock absorbing member is prevented.

It is the schematic of the seismic isolation structure concerning 1st embodiment of this invention. (A) to (c) are schematic top views which show the example of the arrangement | positioning aspect of the impact-absorbing member in 1st embodiment of this invention. It is a partial schematic diagram of the seismic isolation structure concerning a second embodiment of the present invention. (A) to (c) is a schematic side view showing an example of an aspect of a shock absorbing member in a third embodiment of the present invention. (A) is the schematic of normality of the seismic isolation structure provided with the conventional impact absorption member, (b) is the schematic at the time of the vibration generation of the seismic isolation structure provided with the conventional impact absorption member. (A) And (b) is an explanatory view explaining relative position displacement of a building and a building foundation provided with a seismic isolation system. It is an explanatory view explaining movement of the base isolation structure provided with the conventional shock absorption member.

Hereinafter, embodiments of the present invention will be described using the drawings. In all the drawings, the same components are denoted by the same reference numerals, and overlapping descriptions will be appropriately omitted.
The various components of the present invention do not have to be independent entities, but a plurality of components are formed as a single member, and a single component is formed of a plurality of members, It is permitted that one component is a part of another component, that a part of one component and a part of another component overlap, and so on. Although the illustrated embodiment of the present invention may illustrate a specific member as a whole in a relatively large or small size for ease of understanding, the dimensional ratio of each configuration of the present invention may be any It is not limited.

With regard to the description of the present invention or the present specification, in the case of the upper and lower sides without particular notice, the sky direction is from the arbitrary point upward, and the downward direction relative to the sky direction is the downward direction. Further, the horizontal direction in the present invention includes not only a direction strictly perpendicular to the vertical direction but also a substantially horizontal direction intersecting the vertical direction.
In the following description, the end on the side wall side (upper structure side) of the shock absorbing member is referred to as a base end, and the end on the opposite wall side (lower structure side) of the shock absorbing member is referred to as a tip, and in the horizontal direction The upper structure side may be referred to as a proximal side from an arbitrary point between the upper structure and the lower structure, and the lower structure side may be referred to as a distal side.

First Embodiment
Below, 1st embodiment of the seismic isolation structure of this invention is described using FIG. 1 and FIG. Also, in order to explain the prior art, FIGS. 6 and 7 will be used as appropriate. FIG. 1 is a schematic view of a seismic isolation structure 100 according to a first embodiment of the present invention. FIGS. 2 (a) to 2 (c) are schematic top views showing examples of the arrangement of the shock absorbing member 40 in the first embodiment of the present invention.

  The seismic isolation structure 100 is provided with the upper structure 10, the lower structure 20, and the seismic isolation apparatus 30 located between the upper structure 10 and the lower structure 20 as shown in FIG. The lower structure 20 has an opposing wall 22 which faces a part of the side wall 12 of the upper structure 10 and is spaced apart from the side wall 12. In the seismic isolation structure 100, an impact absorbing member 40 provided with a foamed resin body 42 is installed at a position facing the opposing wall 22 of the side wall 12, and a space is provided between the impact absorbing member 40 and the opposing wall 22. The shock absorbing member 40 including the foamed resin body 42 is provided at a position facing the side wall 12 of the facing wall 22 provided with S (aspect 1) or the shock absorbing member 40 and the side wall 12 And a space S is provided (aspect 2). In the present embodiment described below, specifically, the present invention will be described by taking the above aspect 1 as an example.

Since the shock absorbing member 40 is provided in the seismic isolation structure 100 according to the present embodiment, even if the relative positional displacement between the upper structural body 10 and the lower structural body 20 in the horizontal direction is enormous, Direct collision is avoided. Therefore, in the seismic isolation structure 100, the upper structural body 10 and the lower structural body 20 are prevented from directly colliding with each other and being damaged due to the occurrence of a large earthquake or the like.
Further, since the shock absorbing member 40 in the present embodiment is configured using the foamed resin body 42, when the upper structure 10 and the lower structure 20 collide indirectly via the shock absorbing member 40. And the foamed resin body 42 is compressed and deformed to absorb the collision force. Moreover, since the foamed resin body 42 does not exert a repulsive force like rubber even when compressed and deformed, the seismic isolation structure 100 suppresses the swing back of the upper structural body 10 due to the repulsive force of the shock absorbing member 40 absorbing the shock. Be done.
According to the seismic isolation structure 100, even when a large earthquake occurs, the amount of transmission of vibration to the upper structure 10 is reduced, and the vibration itself transmitted from the ground to the lower structure 20 is damped. It is possible to absorb the vibration of the upper structure 10 caused by inertia. Therefore, according to the seismic isolation structure 100, it is possible to reduce the vibration of the upper structural body 10 due to the occurrence of an earthquake or the like, and to shorten the vibration time as compared with the conventional case.
For example, even if the superstructure 10 is a tall building such as a high-rise building that may resonate with long-period ground motion, the implementation of the seismic isolation structure 100 prevents the above-mentioned resonance or the effect of resonance. It is possible to keep it small. By this, it is possible to effectively protect the upper structure 10 from a unique shaking motion such as a continuous shaking due to the occurrence of a long period shaking motion or an increase in shaking.

Also, according to the study of the present inventors, in the case of a general seismic isolation structure not provided with a shock absorbing member, the ground and the lower structure shake significantly (first stage shaking) when an earthquake occurs. The movement of the upper structure is suppressed as the device operates. However, after the quake of the earthquake is settled, there is a case where the inertia acting on the upper structure 10 continues the large movement of the upper structure (second stage vibration). The swing of the second stage may cause the upper and lower structures to collide with each other. The base isolation structure 100 prevents these direct collisions, even when the relative positional displacements of the upper structure 10 and the lower structure 20 become enormous due to the above-mentioned second stage shaking, In addition, the swing back of the upper structural body 10 can be suppressed.
Hereinafter, the seismic isolation structure 100 according to the present embodiment will be described in more detail.

(Upper structure and lower structure)
The upper structural body 10 is a structure provided on the ground, and is a structure capable of damping the shaking of the earthquake by the seismic isolation device 30. For example, the superstructure 10 may be a structure such as a building or a house, a tall structure such as a steel tower or a signboard, or an oil tank where a fire accident has occurred in long-period earthquake motion.
On the other hand, the lower structure 20 is constructed on the ground, and at least a bottom portion 24 where the seismic isolation device 30 is to be installed, stands upward from the bottom portion 24 and a predetermined distance from part of the side surface 12 of the upper structure 10 An opposing wall 22 is provided. For example, the lower structure 20 can also support the load of the upper structure 10 and double as a foundation to be transmitted to the ground. Also, although not shown, the bottom portion 24 may be constructed with a different foundation such as a pile foundation below. The lower structure 20 may be substantially the base of the upper structure 10 or may be a structure in which the base and an arbitrary structure are continuous. For example, the opposing wall 22 may be a base wall that forms the basis of the upper structure 10, or may be a structure including a base wall and any wall continuous with the base wall.
In the present embodiment, the upper structure 10 and the lower structure 20 are cut off via the seismic isolation device 30.

(Base isolation system)
The seismic isolation device 30 is disposed between the upper structure 10 and the lower structure 20 and is located below the upper structure 10. The seismic isolation device 30 cuts the upper structural body 10 and the lower structural body 20 to reduce the vibration transmitted from the lower structural body 20 to the upper structural body 10, and shakes the ground relative to the lower structural body 20. Is a device capable of damping shaking by operating in the horizontal direction when it is transmitted. For example, as the seismic isolation device 30, other than a device that includes an elastic member such as rubber and damps horizontal shaking by shear deformation of the elastic member, a so-called sliding bearing device and the like are exemplified. For example, high damping rubber is preferable as the elastic member. In the present embodiment, a plurality of seismic isolation devices 30 are provided on the bottom portion 24 of the lower structural body 20, and the upper structural body 10 is constructed above the seismic isolation devices 30.

(Impact absorption member)
The shock absorbing member 40 is disposed and fixed at a position facing the opposing wall 22 of the side wall 12 in the upper structure 10. The upper surface of the shock absorbing member 40 in the present embodiment is located at a height lower than the ground surface (GL). However, this does not limit the present invention, and, for example, the opposing wall 22 is the ground surface G.D. In the case of extending to the upper side beyond L, the upper surface of the shock absorbing member 40 is also appropriately selected from the ground surface G.D. It may be arranged to be at a height beyond L. By providing the shock absorbing member 40, even if the relative positional displacement between the upper structural body 10 and the lower structural body 20 is enormous, direct collision between them is avoided. The impact absorbing member 40 in the present embodiment is a rectangular solid made of a solid foamed resin body 42. However, within the scope of the present invention, the present invention includes a foamed resin body 42 in which a void or cavity is formed.

The shock absorbing member 40 includes a foamed resin body. The impact absorbing member 40 in the present embodiment is substantially constituted only of the foamed resin body 42.
When the relative positional displacement between the upper structural body 10 and the lower structural body 20 is enormous, the impact absorbing member 40 and the opposing wall 22 collide, and the foamed resin body 42 is compressed and deformed, whereby the energy of the collision is foamed. It is absorbed by the resin body 42. Therefore, damage to the upper structure 10 and the lower structure 20 due to a collision is prevented. Since the foamed resin body 42 that has been compressed and deformed does not exert a repulsive force like rubber, it is suppressed that the upper structure body 10 is shaken back.
In the foamed resin body 42, compressive deformation absorbing energy of collision mainly means plastic deformation. That is, when the foamed resin body 42 collides with the opposing wall 22, it has a property of plastic deformation promptly, and absorbs the energy of the collision by such plastic deformation. Although it depends on the thickness dimension of the foamed resin body 42 and the size of the sway, generally, the foamed resin body 42 does not plastically deform all at one collision, and the collision surface side is plastically deformed. Leaves an area of non-plastic deformation (area of elastic deformation and shape recovery). Therefore, the foamed resin body 42 can repeatedly absorb the energy of collision. Incidentally, the plastic deformation mentioned here means compressive deformation capable of absorbing the energy of compression, and specifically, not only deformation in which the shape is not restored permanently due to compressive deformation, but also compressive deformation is instantaneous Also includes deformations in which part or all of the shape is restored over time although the shape is not restored.

When the amount of plastic deformation of the foamed resin body 42 exceeds the threshold value, or after a large earthquake or the like occurs, part or all of the foamed resin body 42 may be replaced as appropriate. That is, the foamed resin body 42 in the present invention is a member on the premise of absorbing the energy of collision by plastic deformation, and is a member that can be replaced at an appropriate timing. Since the foamed resin body 42 is lightweight and easy to handle as compared with rubber, the work such as replacement is easy.
The amount of plastic deformation may be a standard when the ratio of the thickness dimension at the time of measurement to the thickness dimension (dimension in the distal end proximal direction) of the foamed resin body 42 immediately after installation is less than the set value.

  Moreover, compared with the seismic isolation structure 500 which uses the conventional rubber as the impact-absorbing member 530, the seismic isolation structure 100 concerning this embodiment can make degradation speed of the seismic isolation apparatus 30 looser, and can extend life. The reason will be described with reference to FIGS. 6 (a) and 6 (b) and FIG. 6 (a) and 6 (b) are explanatory diagrams for explaining the relative positional displacement between the building 510 including the seismic isolation system and the building foundation 550. FIG. FIG. 7 is an explanatory view for explaining the movement of the seismic isolation structure 500 provided with the shock absorbing member 530 made of rubber. 6 (a) and 6 (b) and FIG. 7 show the state observed from the upper surface of the building 510, and the seismic isolation device provided below the building 510 is not shown.

  Seismic vibrations are transmitted to the building foundation 550 from various directions through the ground. The seismic vibration (vibration) transmitted from the ground is attenuated by the shear deformation of rubber (hereinafter referred to as seismic isolation rubber) provided in the seismic isolation device, in which case the relative position between the building foundation 550 and the building 510 Position displacement occurs. The relative positional displacement between the building foundation 550 and the building 510 is not only generated linearly as in the direction of the arrow a1 as shown in FIG. 6A, but also as shown in FIG. Like direction, it may occur in the direction of rotation. However, in any case of FIGS. 6 (a) and 6 (b), the seismic isolation rubber provided in the seismic isolation device has a direction opposite to the shear direction after shear deformation (ie, the direction of arrow a2 in FIG. 6 (a) Or, it operates in the direction of the arrow b2 in FIG. 6 (b) and tries to return to the original shape. Generally, rubber tends to deteriorate more quickly as the direction of deformation extends in multiple directions, so when shear deformation occurs in the seismic isolation rubber due to an earthquake etc., the seismic isolation rubber concerned is opposite to the shear direction. It is desirable to move in the direction and quickly return to its original shape.

  However, as shown in FIG. 7, in the seismic isolation structure 500 provided with the shock absorbing member 530 made of rubber, relative positional displacement between the building foundation 550 and the building 510 occurs in the rotational direction (direction of arrow b1). In the case of collision with 530, the building 510 is shaken back in an indefinite direction (for example, arrow c1 direction, arrow c2 direction) that is not directly related to the swinging direction (ie, arrow b1 direction) by the repulsive force of the shock absorbing member 530. . Therefore, the seismic isolation rubber provided in the seismic isolation device returns to its original shape while repeating shear deformation in a complicated direction, and the degradation of the seismic isolation rubber proceeds, resulting in the life of the seismic isolation device. There was a risk of shortening.

  On the other hand, the seismic isolation structure 100 concerning this embodiment equips the upper structure body 10 side with the impact-absorbing member 40 using the foamed resin body 42 instead of rubber | gum. As described above, since the foamed resin body 42 does not easily generate a repulsive force like rubber, the seismic isolation rubber provided in the seismic isolation device 30 is sheared in the rotational direction (refer to the arrow b1 direction in FIG. 7). Even in the case where the facing wall 40 collides with 40, the swing back in an indeterminate direction as shown in FIG. 7 is suppressed. Therefore, in the seismic isolation structure 100, after the seismic isolation rubber provided in the seismic isolation device 30 shear-deforms in the rotational direction, the degradation progresses by returning to the original shape while repeating the shear deformation in complex directions. The problem is prevented.

  In the present embodiment, as shown in FIG. 1, a space S is secured between the impact absorbing member 40 and the inner side surface of the opposing wall 22 (the surface on the side facing the upper structure 10). As a result, when vibration occurs on the ground, the seismic isolation structure 100 has a relative positional displacement between the upper structural body 10 and the lower structural body 20 within a range that does not physically affect the shock absorbing member 40. Tolerate. In other words, by ensuring the space S, the shock absorbing member 40 is not constantly subjected to the impact load due to the occurrence of slight ground shaking or the like.

The distance m between the shock absorbing member 40 and the facing wall 22 via the space S is not particularly limited. However, if the distance m is too small, the shock absorbing member 40 collides with the opposing wall 22 even if it shakes slightly, and the load of the foamed resin body 42 constituting the shock absorbing member 40 becomes large. As a result, the energy absorbing effect of the shock absorbing member 42 in the case of a large earthquake may be reduced, or the frequency of replacement of the shock absorbing member 40 may be increased. From this point of view, the distance m is, for example, preferably 3 cm or more, more preferably 5 cm or more, and still more preferably 8 cm or more.
Also, if the distance m is too large, the shear deformation of the seismic isolation rubber provided in the seismic isolation device 30 may be large, and the degradation of the seismic isolation rubber may proceed, and the inertia force of the seismic isolation device 30 causes a secondary The resulting swing of the upper structure 10 may continue for a long time. From this point of view, the distance m is preferably 100 cm or less, more preferably 50 cm or less, still more preferably 30 cm or less, and particularly preferably 10 cm or less.

The upper structure provided with the conventional seismic isolation system is more likely to shake by a small to medium-sized earthquake or strong wind, and the oscillation tends to be sustained compared with the upper structure without the seismic isolation device. The This is because the seismic isolation rubber in the seismic isolation device undergoes shear deformation. Such shaking may cause discomfort to people in the upper structure.
On the other hand, in the present embodiment, if the distance m in the space S is in a suitable range of 3 cm to 100 cm, the upper structure 10 may be affected even by a small-scale earthquake or strong wind. It is possible to suppress the occurrence of shaking and the duration of shaking.

  The dimension n from the proximal end to the distal end of the impact absorbing member 40 is not particularly limited, and can be appropriately determined in consideration of the above-described distance m, the size of the upper structure 10, and the like.

  As shown in FIG. 1, the shock absorbing member 40 is installed at a position facing the opposing wall 22 of the side wall 12 of the upper structure 10. The shock absorbing member 40 may be provided continuously in the circumferential direction of the upper structure 10, but as shown in FIG. 2A, intermittently at any position in the circumferential direction of the upper structure 10 Once deployed, initial challenges can be achieved sufficiently. A plurality of impact absorbing members 40 can be disposed at appropriate intervals, and each of the plurality of impact absorbing members 40 disposed intermittently can be checked and replaced as appropriate after an earthquake occurs or in a periodic inspection or the like.

Moreover, the corner part of the upper structure 10 is mentioned as an example of the location which the upper structure 10 and the lower structure 20 collide easily. Therefore, as shown in FIG. 2 (b), the impact absorbing member 40 is disposed in the vicinity of the apex 16 of the corner of the upper structure 10, or as shown in FIG. 2 (c), the corners of the upper structure 10. It is preferable that the shock absorbing member 40 be disposed at a position covering the top 16 of the part. According to this aspect, even if the seismic isolation rubber provided in the seismic isolation device 30 shears in the rotational direction, the collision of the apex 16 with the opposing wall 22 of the lower structure 20 is avoided. it can.
Here, the vertex 16 means a vertex identified in the cross section when the upper structure 10 is cut in the horizontal direction. That the shock absorbing member 40 is disposed in the vicinity of the apex 16 means that the end on the apex 16 side of the impact absorbing member 40 is disposed at a position in contact with the apex 16. It includes up to an aspect in which the shock absorbing member 40 is disposed at a position closer to either of the apexes 16 than the midpoint 18 which is a point of a half.

  As the foamed resin body 42, one obtained by in-mold foam molding is preferable to one obtained by extrusion foam molding. The extrusion-foamed extruded foam resin body tends to buckle rapidly at a few percent compression strain (%), but the in-mold foam resin body in-mold foam increases the compression strain (%) This is because the compressive stress gradually increases without buckling.

  The foamed resin body 42 used for the impact absorbing member 40 may be any one as long as it exerts appropriate impact absorbing power, and is made of, for example, a polypropylene resin foam, a polystyrene resin foam, or a polyethylene resin foam. be able to. Among them, as the foamed resin body 42, a polypropylene resin foam or a polyethylene resin foam is preferable, a polypropylene resin foam is more preferable, and a polypropylene resin foam formed by in-mold foaming is more preferable . This is because polypropylene resin foam and polyethylene resin foam are highly resistant to compressive strain.

  In general, foamed resin bodies (hereinafter, also referred to as foamed resin bodies for foundations) used for a part of a building foundation or replacement ground are not intended to be repeatedly replaced, and also for the load of a building or a ground Those having physical properties that can withstand in the long term are selected. Specifically, as the base foam resin body, EPS (polystyrene resin molded by in-mold foaming), which is excellent in long-term creep characteristics, and the like are preferable examples. On the other hand, a polypropylene resin or a polystyrene resin formed by in-mold foaming tends to have a high compressive stress and a high energy absorption amount at the same resin amount, and is suitable as the foamed resin body 42. In addition, the polypropylene resin foam or the polystyrene resin foam which has been subjected to in-mold foam molding can absorb an impact well by the deformation of each foam resin particle. The foamed resin body 42 that has absorbed energy is partially plastically deformed, but the foamed resin body 42 whose plastic deformation amount has increased due to the collision may be replaced as appropriate.

Foamed resin body 42 is preferably higher moderately compressive strength, the lower limit of the compressive strength of the foamed resin body 42 is preferably 50 kN / m ² or more, more preferably 100 kN / m ² or more, more preferably It is 150 kN / m ² or more.
The upper limit of the compressive strength of the foamed resin body 42 is not particularly limited, but is preferably 400 kN / m ² or less, more preferably 300 kN / m ² or less. When the upper limit range of the compressive strength of the foamed resin body 42 is the above-mentioned range, the collision energy between the impact absorbing member 40 and the opposing wall 22 is favorably absorbed.
The said compressive strength can be measured according to the measuring method shown by JISK7220: 2006. Specifically, a test piece of about 50 mm in longitudinal dimension × about 50 mm in transverse dimension × about 50 mm in thickness is prepared, and the specimen is compressed at a loading speed of 10 mm / min to measure compressive stress at 5% compression strain. Can.

Second Embodiment
Below, 2nd embodiment of the seismic isolation structure of this invention is described using FIG. FIG. 3 is a partial schematic view of the seismic isolation structure 100 according to the second embodiment of the present invention. In the seismic isolation structure 100 according to the second embodiment, the impact absorbing member 40 is provided with the load distribution plate 44, and the upper structural body 10 and the lower structural body 20 are provided with the metal reinforcing means 50. The second embodiment is different from the first embodiment, and the other points can be appropriately implemented in the same manner as the first embodiment. Therefore, in the following, the configuration specific to the second embodiment will be mainly described.

  In the shock absorbing member 40 in the present embodiment, a load distribution plate 44 extending in a direction substantially parallel to the side wall 12 is disposed in the middle portion. Here, the middle part means an arbitrary position between the tip end and the base end of the shock absorbing member 40. Foamed resin bodies 42 and 42 are disposed on the distal end side and the proximal end side of the load distribution plate 44, respectively. The impact absorbing member 40 in the present embodiment has a side surface 42 a on the tip end side of the foamed resin body 42 on the base end side and a side surface 42 b on the base end side of the foamed resin body 42 on the tip side with reference to the load distribution plate 44. , And are joined to both sides of the load distribution plate 44, respectively.

  The load distribution plate 44 is a member for uniformly transmitting the impact force (load) loaded at the tip end portion of the impact absorbing member 40 to the proximal end side. Since the impact force (load) is dispersed by the impact absorbing member 40 and transmitted to the foamed resin body 42 on the proximal end side, the deterioration of the foamed resin body 42 located on the proximal side with respect to the load distribution plate 44 may be delayed. it can. Therefore, it is preferable to replace only the foamed resin body 42 on the tip end side with respect to the load distribution plate 44 as appropriate after an earthquake occurs or in a periodic inspection or the like.

  The load distribution plate 44 may be a member capable of receiving the load applied to the foamed resin body 42 on the tip end side and dispersing the load in the plane, for example, a metal plate or a hard resin plate having a predetermined thickness. Is not limited to this. As a more specific example, it is preferable that the load distribution plate 44 is a plate-like body made of a metal member such as stainless steel or iron which has been subjected to rustproofing, and the foamed resin body 42 is a polypropylene based resin foam. This is because metals such as iron and stainless steel and polypropylene-based resin foams are firmly joined by a simple method such as heat fusion. Therefore, when replacing the foamed resin body 42 on the tip end side, the foamed resin body 42 on the tip end side is peeled off from the load distribution plate 44 which is a metal plate and removed, and thereafter, the new foamed resin body 42 is thermally fused. It can be easily joined to the surface of the load distribution plate 44.

  The dimensions and shape of the load distribution plate 44 are not particularly limited. For example, from the viewpoint that the load from the front end side can be dispersed on average by the base end side blowing resin body 42, the load distribution plate 44 has a side surface 42a of the front end side of the foamed resin body 42; It is preferable that they have substantially the same shape.

  In the seismic isolation structure 100 according to the present embodiment, at least one of the first region 56 in which the shock absorbing member 40 of the side wall 12 is disposed or the second region 58 facing the shock absorbing member 40 of the opposing wall 22 is metal. Reinforcement means 50 are provided. FIG. 3 illustrates an example in which the metal reinforcing means 50 is provided in both the first region 56 and the second region 58. The metal reinforcing means 50 may be provided in the same area range as each of the first area 56 and the second area 58, or as shown in FIG. 3, an area larger than this including the first area 56 or the second area 58 It may be provided in a range.

  Conventional seismic isolation structures provided with seismic isolation devices often have their strengths calculated on the premise that a building (upper structure) and a building foundation (substructure) do not collide. Therefore, in the case of implementing the seismic isolation structure 100 by providing the shock absorbing member 40 as a retrofit to the conventional seismic isolation structure, the predetermined structure from the viewpoint of protecting the upper structural body 10 and the lower structural body 20 more sufficiently. Preferably, metal reinforcement means 50 are provided in the area.

  The metal reinforcing means 50 is a means for improving the structural strength of a predetermined area using a metal member. As shown in FIG. 3, the metal reinforcing means 50 in the present embodiment is a plate-like metal member made of a stainless steel plate, an iron plate subjected to rust proofing, or the like. That is, reinforcement is implemented by fixing to the 1st area | region 56, the area | region containing the 2nd area | region 58) with fixing tools 52, such as an anchor bolt. By thus arranging and fixing the metal reinforcing means 50 such as a metal plate from the surface of the upper structure 10 or the lower structure 20 in the predetermined region, the protection of the seismic isolation structure 100 can be easily reinforced even after mounting. . As installation of the other metal reinforcement means 50 which is not shown in figure, a metal plate is embed | buried inside the predetermined area | region of the upper structure 10 or the lower structure 20, or the number of rebars is increased etc. is mentioned.

  By the way, in the present embodiment, a metal plate is disposed and fixed in the first region 56 of the side wall 12 of the upper structure 10 as the metal reinforcing means 50. The base end portion of the shock absorbing member 40 is joined to the surface on the front end side of the metal plate, and the metal plate is also used as the substrate 54 of the shock absorbing member 40. As described above, in the present embodiment, the shock absorbing member 40 is supported by the metal plate which is the substrate 54, and the substrate 54 is disposed in a predetermined region, so that the shock absorbing member 40 with respect to the upper structure 10 is The mounting posture is stable. By combining the metal plate as the substrate 54 and the metal reinforcing means 50 in this manner, both the installation stability of the impact absorbing member 40 and the reinforcement of the upper structure 10 can be achieved with a small number of parts. In addition, when not sharing with the metal reinforcement means 50 is considered, the board | substrate 54 may be comprised from members other than a metal.

Third Embodiment
Below, 3rd embodiment of the seismic isolation structure of this invention is described using FIG. 4 (a)-FIG.4 (c). FIGS. 4 (a) to 4 (c) are schematic side views showing examples of various aspects of the shock absorbing member 40 in the third embodiment of the present invention. The shock absorbing member 40 shown in the third embodiment can be appropriately used as the shock absorbing member 40 in the seismic isolation structure 100 described in the first embodiment or the second embodiment.

  In the shock absorbing member 40 described in the present embodiment, the cross-sectional area decreases continuously or intermittently from the side wall 12 toward the opposing wall 22. In other words, in the impact-absorbing member 40 in the present embodiment, the area of the cut surface formed by cutting perpendicularly to the proximal direction connecting the proximal side and the distal side is from the proximal side toward the distal side. It is decreasing continuously or intermittently. As described above, the impact absorbing member 40, which has a smaller cross-sectional area closer to the tip end, is likely to be plastically deformed when it collides with the opposing wall 22, and to easily absorb the impact. In the impact absorbing member 40 in the present embodiment, when only the foamed resin body constituting the distal end side is plastically deformed, only the foamed resin body on the distal end side including the plastically deformed portion needs to be replaced with a new foamed resin body. Is easy.

  The shock absorbing member 40 shown in FIG. 4A includes a foamed resin body 42 whose cross-sectional area continuously decreases from the proximal end toward the distal end. The foamed resin body 42 has a conical shape having a tip 45 with a predetermined area, and the side surface is tapered. The area of the proximal end 46 of the impact absorbing member 40 is larger than the area of the distal end 45. The base end 46 of the conical foam resin 42 is bonded to one side of the substrate 54, and the substrate 54 is fixed to the side wall 12 of the upper structure 10 by a fixing tool 52 such as an anchor bolt. . When the tip side of the conical foam resin body 42 is plastically deformed, the entire foamed resin body 42 may be separated from the substrate 54 and replaced with a new foamed resin body, but part of the tip side including the plastically deformed portion is cut Alternatively, the foam resin body 42 may be partially replaced.

  The shock absorbing member 40 shown in FIG. 4B includes a foamed resin body whose cross-sectional area decreases intermittently from the proximal side to the distal side. The foamed resin body may be integrally molded, but as illustrated, the distal end block 47, the intermediate block 48, and the proximal end block 49 are separately formed, and these are sequentially joined to form the stepped foam You may comprise a resin body. Although FIG. 4 (b) shows an aspect in which one intermediate block 48 is disposed between the distal end block 47 and the proximal end block 49, the number of intermediate blocks 48 may be two or more, or It does not have to be. Each of the distal end block 47, the intermediate block 48, and the proximal end block 49 is a structure having substantially the same cross-sectional area, and is, for example, a cylinder, a rectangular parallelepiped, or a cube. In the step-like foamed resin, when only the end block 47 or the end block 47 and the intermediate block 48 are plastically deformed, they may be separated in block units and replaced with a new block-shaped foamed resin.

The shock absorbing member 40 shown in FIG. 4C has a structure in which the proximal end block 49 has substantially the same cross-sectional area, and the distal end block 47 is tapered toward the distal end, and has a distal end 45 of a predetermined area. It has a conical shape. Thus, the foamed resin body constituting the impact absorbing member 40 may have both a point where the cross-sectional area decreases intermittently and a point where the cross-sectional area decreases continuously.
Further, in the shock absorbing member 40 shown in FIG. 4C, a load distribution plate 44 is provided between the distal end block 47 and the proximal end block 49. By providing the load distribution plate 44 at any boundary where the size of the cross-sectional area changes, the load received by the small-area foamed resin body can be favorably dispersed to the large-area foamed resin body. Of course, the load distribution plate 44 may be disposed at any position in the distal end proximal direction of the shock absorbing member 40 shown in FIG. 4 (a), or with the distal end block 47 of the shock absorbing member 40 shown in FIG. In the case of having a boundary with the intermediate block 48, a boundary between the intermediate block 48 and the proximal block 49, or two or more intermediate blocks 48 not shown, the load distribution plate 44 is provided at the boundary between the intermediate blocks 48, 48. It may be arranged.

  When joining a plurality of foamed resin blocks and forming a foamed resin body used for the impact absorbing member 40 as shown in FIG. 4 (b) or FIG. 4 (c), the plurality of foamed resin blocks are identical members. The same physical properties may be used, or different members and / or foamed resin blocks having different physical properties may be used.

  Although the first to fourth embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications, improvements, etc. can be made as long as the object of the present invention is achieved. And the aspect of

The above embodiment includes the following technical ideas.
(1) An upper structure, a lower structure, and a seismic isolation device positioned between the upper structure and the lower structure, the lower structure comprising one of the side walls of the upper structure An impact absorbing member having a foamed resin body is provided at a position facing the opposing wall, having an opposing wall facing the portion and separated from the side wall, and the impact absorbing member and the impact absorbing member A space is provided between the opposing wall, or an impact absorbing member provided with a foamed resin body is disposed at a position facing the side wall of the opposing wall, and the impact absorbing member and the impact absorbing member A seismic isolation structure characterized by the provision of a space between it and the side wall.
(2) The seismic isolation structure according to claim 1, wherein the foamed resin body is a polypropylene resin foam or a polyethylene resin foam.
(3) The seismic isolation structure according to claim 1 or 2, wherein a load distribution plate extending in a direction substantially parallel to the side wall is disposed at an intermediate portion of the shock absorbing member.
(4) The seismic isolation structure according to any one of claims 1 to 3, wherein the shock absorbing member is disposed in the vicinity of the vertex of the corner of the upper structure or at a position covering the vertex.
(5) The metal reinforcing means is provided in at least one of the first region of the side wall where the shock absorbing member is disposed, or the second region of the opposing wall opposite to the shock absorbing member. The seismic isolation structure according to any one of 4.
(6) The seismic isolation structure according to any one of claims 1 to 5, wherein in the shock absorbing member, the cross-sectional area decreases continuously or stepwise from the side wall toward the opposing wall.

DESCRIPTION OF REFERENCE NUMERALS 10 upper part structure 12 side wall 16 apex 18 middle point 20 lower part structure 22 opposite wall 24 .... bottom 30 ----- isolator 40 ----- shock absorbing member 42 ----- foamed resin body 42a, 42b ..... side 44 ----- load distribution plate 45 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·. Means 52: Fixing member 54: Substrate 56: First region 58: Second region 100: Isolation structure 500: Isolation Vibration structure 512 ··· Side wall 510 ··· Building 520 ··· Retaining wall inner surface 522 ··· Retaining wall 530 · · · Shock absorbing member 540 · · · Isolator 550 ----- building foundation a1, a2, b1, b2, c1, c2 ····· arrow m ----- distance n ----- dimension S ..... space

The seismic isolation structure of the present invention comprises an upper structural body, a lower structural body, and a seismic isolation device positioned between the upper structural body and the lower structural body, and the lower structural body is the upper structure A shock absorbing member is provided, which has a facing wall facing a part of the side wall of the body and separated from the side wall, and having a foamed resin body at a position facing the facing wall on the surface of the side wall A space is provided between the shock absorbing member and the opposite wall, or a shock absorbing member provided with a foamed resin body is provided on the surface of the opposite wall at a position facing the side wall And a space is provided between the shock absorbing member and the side wall, and the distance between the shock absorbing member installed on the surface of the side wall and the opposing wall or the surface of the opposing wall is provided The shock absorbing member and the opposing wall Distance may be smaller than the shortest distance between the side wall and the opposite wall.

The seismic isolation structure of the present invention comprises an upper structural body, a lower structural body, and a seismic isolation device positioned between the upper structural body and the lower structural body, and the lower structural body is the upper structure A shock absorbing member is provided, which has a facing wall facing a part of the side wall of the body and separated from the side wall, and having a foamed resin body at a position facing the facing wall on the surface of the side wall A space is provided between the shock absorbing member and the opposite wall, or a shock absorbing member provided with a foamed resin body is provided on the surface of the opposite wall at a position facing the side wall And a space is provided between the shock absorbing member and the side wall, and the distance between the shock absorbing member installed on the surface of the side wall and the opposing wall or the surface of the opposing wall is provided and said impact absorbing member and the side wall which is Away may be smaller than the shortest distance between the side wall and the opposite wall.

Claims (6)

An upper structure, a lower structure, and a seismic isolation device located between the upper structure and the lower structure;
The lower structure has an opposite wall facing to a part of the side wall of the upper structure and separated from the side wall,
An impact absorbing member provided with a foamed resin body is installed at a position facing the opposing wall of the side wall, and a space is provided between the impact absorbing member and the opposing wall, or
An impact absorbing member provided with a foamed resin body is installed at a position facing the side wall of the opposing wall, and a space is provided between the impact absorbing member and the side wall. Seismic isolation structure.   The seismic isolation structure according to claim 1, wherein the foamed resin body is a polypropylene resin foam or a polyethylene resin foam.   The seismic isolation structure according to claim 1 or 2, wherein a load distribution plate extending in a direction substantially parallel to the side wall is disposed at an intermediate portion of the shock absorbing member.   The seismic isolation structure according to any one of claims 1 to 3, wherein the shock absorbing member is disposed in the vicinity of the apex of the corner of the upper structure or at a position covering the apex.   The metal reinforcing means is provided in at least one of a first region of the side wall where the shock absorbing member is disposed, or a second region of the opposing wall opposite to the shock absorbing member. The seismic isolation structure according to any one of the above. The seismic isolation structure according to any one of claims 1 to 5, wherein in the shock absorbing member, the cross-sectional area decreases continuously or stepwise from the side wall toward the opposing wall.

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