JP2018071651A - Base isolation structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cots and also suppress excessive displacement.SOLUTION: A base isolation structure includes a base isolation layer having a space with a predetermined height from a lower structure, between an upper structure and the lower structure. The base isolation layer includes: an erected part erecting from the lower structure so as to be higher than a predetermined height; a base isolation mechanism provided between the upper structure and the erected part; a drooped part drooping from the upper structure to a predetermined height, and separated from the erected part in a horizontal direction; and a contact part provided on at least one of the erected part and drooped part, and configured to, when the upper structure and the lower structure are relatively displaced by a predetermined distance in the horizontal direction, contact with the other one of the erected part and drooped part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a seismic isolation structure.

  There is known a seismic isolation structure in which a seismic isolation device (for example, laminated rubber) or a damping device (for example, a damper) is provided in a gap between an upper structure and a lower structure in a building or the like.

  Further, in Patent Document 1, a base (concave member) that protrudes downward is provided in the upper structure, and a base (convex member) that protrudes upward is provided in the lower structure. A structure is described in which excessive displacement between the structure and the substructure is suppressed.

JP 2014-35019 A

  However, it is costly to install a pair of excessive displacement suppression foundations as described above. Especially in the case of middle-layer seismic isolation that installs a seismic isolation device between the upper and lower part of the building (intermediate floor), and stigma isolation that installs a seismic isolation device on the head of a specific floor (such as the first floor) The distance between the upper structure and the lower structure (the height of the base isolation layer) is often larger than that of the base base isolation, which may increase the cost. Further, it is necessary to greatly increase the cross-sectional area of the foundation and the bar arrangement so as to resist the bending moment at the time of collision, which may further increase the cost.

  This invention is made | formed in view of this subject, The place made into the objective is to suppress an excessive displacement, aiming at the reduction of cost.

In order to achieve such an object, the seismic isolation structure of the present invention is a seismic isolation structure including a base isolation layer having a space of a predetermined height from the lower structure between the upper structure and the lower structure, The seismic isolation layer includes a standing part standing higher than the predetermined height from the lower structure, a seismic isolation mechanism provided between the upper structure and the standing part, and a predetermined height from the upper structure. A drooping portion that hangs down from the standing portion, and is provided on one of the standing portion and the drooping portion, and the upper structure and the lower structure are arranged in the horizontal direction. And an abutting portion that abuts against the other of the standing portion and the hanging portion when a predetermined distance is relatively displaced.
According to such a seismic isolation structure, it is possible to suppress excessive displacement while reducing costs.

In such a seismic isolation structure, it is preferable that the contact portion includes a cushioning material.
According to such a seismic isolation structure, it is possible to buffer an impact caused by contact.

In this seismic isolation structure, when the predetermined distance is c and the length of the abutting portion in the horizontal width direction orthogonal to the horizontal direction is a, the other of the standing portion and the hanging portion The length in the horizontal width direction is preferably (a / 2 + c) or more on one side and the other side in the horizontal width direction from a position corresponding to the center in the horizontal width direction of the contact portion.
According to such a seismic isolation structure, even if the direction of vibration is oblique to the horizontal direction or the horizontal width direction, it is possible to facilitate contact.

In this seismic isolation structure, the standing portion may be a planar polygonal columnar body, and the hanging portion may be provided on a side of each side surface of the columnar body.
According to such a seismic isolation structure, excessive displacement can be suppressed regardless of the direction of vibration.

In this seismic isolation structure, the standing portion may be a planar circular columnar body, and the hanging portion may be provided on a lateral side of the columnar body.
According to such a seismic isolation structure, excessive displacement can be suppressed regardless of the direction of vibration.

In this seismic isolation structure, the hanging part may integrally surround the standing part.
According to such a seismic isolation structure, excessive displacement can be reliably suppressed.

In this seismic isolation structure, it is desirable that the predetermined height is 2.1 m or more.
According to such a seismic isolation structure, a living room can be configured.

In this seismic isolation structure, the hanging part includes a first part including a range from the predetermined height to a height of the standing part, and a second part between the first part and the superstructure. It is desirable that the first part is more easily plastically deformed than the second part.
According to such a seismic isolation structure, it is possible to prevent excessive stress from being applied to the standing portion and the upper structure.

In this seismic isolation structure, the hanging part may be a lifting equipment or a mechanical equipment room hanging from the upper structure.
According to such a seismic isolation structure, it is possible to further reduce the cost.

In such a base isolation structure, the base isolation mechanism may be a high damping laminated rubber.
According to such a base isolation structure, the functions of base isolation, restoration, and attenuation can be realized independently.

In such a seismic isolation structure, the seismic isolation mechanism may be an elasto-plastic bearing, a rigid plastic bearing, or an elastic sliding bearing.
According to such a seismic isolation structure, it is possible to reduce the burden load on the standing portion.

In this seismic isolation structure, the seismic isolation layer includes a plurality of the standing portions, and the seismic isolation mechanism, the hanging portion, and the contact portion are provided with respect to the certain standing portion. It is desirable that a seismic isolation mechanism having a higher maximum load in the horizontal direction than that of the seismic isolation mechanism is provided between the other standing part and the upper structure.
According to such a seismic isolation structure, even if the seismic isolation mechanism of a certain standing part yields, the upper structure can be supported by the seismic isolation mechanism of another standing part.

  The seismic isolation mechanism may be a restoration mechanism or a damping mechanism.

  According to the present invention, it is possible to suppress excessive displacement while reducing costs.

It is an elevation view which shows the structure of the vibration isolation structure of 1st Embodiment. It is an AA 'top view of FIG. It is a figure which shows the example of arrangement | positioning of a protrusion base and a shock absorbing material. It is a figure which shows the 1st modification of the seismic isolation structure of 1st Embodiment. It is a figure which shows the 2nd modification of the seismic isolation structure of 1st Embodiment. It is a figure which shows the 3rd modification of the seismic isolation structure of 1st Embodiment. It is an elevation view which shows the structure of the vibration isolation structure of 2nd Embodiment. It is an elevation view which shows the structure of the vibration isolation structure of 3rd Embodiment. It is a figure which shows the modification of a protruding foundation. It is a figure which shows the restoring force characteristic of the protruding foundation of FIG. 9, and a shock absorbing material. It is a figure which shows the modification of a seismic isolation structure.

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

=== First Embodiment ===
<About seismic isolation structure>
FIG. 1 is an elevation view showing the configuration of the vibration isolation structure of the first embodiment. FIG. 2 is a plan view taken along the line AA ′ of FIG. In the following description, the direction is determined as shown in the figure. That is, one of the two directions orthogonal to each other on the horizontal plane is taken as the X-axis direction, and the other is taken as the Y-axis direction. A direction perpendicular to the horizontal plane (a direction orthogonal to the X-axis direction and the Y-axis direction) is defined as a Z-axis direction (vertical direction).

  As shown in FIG. 1, the seismic isolation structure of the present embodiment is configured to include a seismic isolation layer S between the upper structure 2 and the lower structure 4. In addition, the seismic isolation structure of this embodiment is a capital isolation, and the upper structure 2 and the lower structure 4 are structures (floor etc.) which comprise the specific floor (for example, 1st floor) of a building. The upper structure 2 is provided above the lower structure 4 with the seismic isolation layer S interposed therebetween. The lower structure 4 supports the upper structure 2 and transmits a load to the ground.

  The seismic isolation layer S is provided with a space K having a height h (corresponding to a predetermined height) from the lower structure 4. In other words, the seismic isolation layer S has a space K having a height h from the lower structure 4. In this embodiment, the space K is a living room, and the ceiling height (height h) is 2.1 m or more (Building Standard Act). For this reason, the height of the base isolation layer S of the present embodiment (the interval between the upper structure 2 and the lower structure 4) is larger than the height of the base isolation base. The space K is not limited to a living room. For example, it may be a service space or a parking facility in a building.

  Moreover, the seismic isolation layer S of this embodiment is provided with the seismic isolation apparatus 10, the base 22 for seismic isolation, the column part 42 (equivalent to a standing part), and the protruding foundation 24 (equivalent to a drooping part).

  The base for seismic isolation 22 is a base for installing the base isolation device 10 and is provided so as to protrude downward (the base isolation layer S) from the upper structure 2.

  The column part 42 is a columnar body erected upward from the lower structure 4. Moreover, as shown in FIG. 1, the height (height H) of the column part 42 in the Z-axis direction is higher than the height h (H> h). Moreover, as shown in FIG. 2, the planar shape of the column part 42 of this embodiment is a quadrangle (planar quadrangle). Specifically, the planar shape of the pillar portion 42 is a square having a side length L as shown in FIG. The column part 42 and the base for seismic isolation 22 have the same position in the horizontal direction (X-axis direction, Y-axis direction) (not separated in the horizontal direction).

  As shown in FIG. 2, the seismic isolation device 10 is interposed between the upper structure 2 and the lower structure 4. More specifically, the seismic isolation device 10 is provided between the base 22 for seismic isolation and the column part 42.

  As shown in FIG. 2, the seismic isolation device 10 of the present embodiment has a laminated rubber 12 (for example, a columnar elastic body formed by alternately laminating circular thin steel plates and rubber layers) in a pair of upper and lower sides. Are sandwiched between flange plates (upper flange plate 13a and lower flange plate 13b). Further, the lower flange plate 13b is fixed to the upper surface of the column portion 42 by bolts (not shown) or the like, and the upper flange plate 13a is fixed to the lower surface of the seismic isolation base 22 by bolts (not shown). The seismic isolation device 10 supports the upper structure 2, and the laminated rubber 12 shears and deforms in the horizontal direction according to the horizontal force due to the relative displacement between the upper structure 2 and the lower structure 4, thereby Increase the period of vibration (function as a seismic isolation bearing). Moreover, the laminated rubber 12 of this embodiment is a high-damping laminated rubber having a lead plug (damping material) provided therein, and also has a damping function (in addition to the seismic isolation function and the restoration function).

  By providing the seismic isolation device 10 between the upper structure 2 and the lower structure 4, when horizontal vibration occurs, the vibration of the upper structure 2 can be lengthened, and the upper structure 2 and the lower structure 4 can be damped.

  However, if the horizontal displacement (relative displacement) between the upper structure 2 and the lower structure 4 becomes excessive, the amount of deformation of the laminated rubber 12 increases, and the laminated rubber 12 may break, There is a risk that you will not be able to support the earthquake. For this reason, it is necessary to suppress excessive displacement. For example, a pair of members (foundations) for suppressing excessive displacement may be provided in the upper structure 2 and the lower structure 4, but in this case, the cost may increase. In particular, in the case of stigma isolation as in the present embodiment, since the distance between the upper structure 2 and the lower structure 4 (height of the seismic isolation layer S) is large, it is expensive to provide a pair of foundations. Therefore, in the present embodiment, by providing the protruding foundation 24 in the upper structure 2, excessive displacement is efficiently suppressed while reducing costs.

  The protruding foundation 24 is a member (foundation) provided to suppress excessive displacement, and hangs down from the upper structure 2 to a height h. Further, the protruding foundation 24 is separated from the column portion 42 in the horizontal direction (X-axis direction in FIGS. 1 and 2). As shown in FIG. 2, the planar shape of the protruding foundation 24 is a quadrangle (square) whose one side is shorter than the column part 42. Since the height H of the column portion 42 is higher than the height (height h) of the lower surface of the protruding foundation 24, the column portion 42 and the protruding foundation 24 partially overlap in the Z-axis direction. .

  Further, in this overlapping portion, a cushioning material 30 (corresponding to a cushioning portion) is provided on a portion (side surface) of the protruding foundation 24 facing the column portion 42.

  The buffer material 30 is an elastic member (for example, rubber) having a predetermined elastic coefficient. By providing the cushioning material 30, it is possible to mitigate an impact when the protruding foundation 24 and the column part 42 collide with each other.

  As shown in FIG. 2, the cushioning material 30 is separated from the column portion 42 by a predetermined distance (here, length c) in the X-axis direction. Therefore, when the protruding foundation 24 is displaced by the length c in the X-axis direction with respect to the column part 42 (when the upper structure 2 and the lower structure 4 are displaced by the length c in the X-axis direction), the cushioning material 30 is It abuts on the part 42. That is, in the present embodiment, the cushioning material 30 corresponds to a contact portion. By this contact, a relative displacement (excessive displacement) larger than the length c can be suppressed.

  In the present embodiment, as shown in FIG. 2, the length L of one side of the pillar portion 42 in the width direction (corresponding to the horizontal width direction) is set to the length in the width direction of the end face (side surface) of the cushioning material 30. It is longer than a. Specifically, L = a + 2c. More specifically, the length L of the column part 42 is respectively set to one side and the other side in the Y-axis direction from the position corresponding to the midpoint of the buffer material 30 in the width direction (here, the Y-axis direction) (a / 2 + c). In this case, the angle between the line (dashed line in the figure) connecting the column part 42 and the corner of the cushioning material 30 and the X axis (and the Y axis) is 45 °. However, the length of the column part 42 is longer than (a / 2 + c) from the position corresponding to the midpoint of the buffer material 30 in the Y-axis direction to one side and the other side in the Y-axis direction. May be. That is, it is desirable that L ≧ a + 2c. By doing so, it is easy to bring the cushioning material 30 (projecting foundation 24) into contact with the column portion 42 even if the direction of vibration is oblique to the X-axis direction and the Y-axis direction.

  In particular, when arranged as shown in FIG. 3, the cushioning material 30 can be brought into contact with the column portion 42 regardless of the direction of vibration. FIG. 3 is a diagram illustrating an arrangement example of the protruding foundation 24 and the cushioning material 30. In FIG. 3, projecting foundations 24 are provided on the sides of the side surfaces (four side surfaces) of the column portion 42. That is, the protruding foundation 24 is provided at a position where the column portion 42 is sandwiched in the X-axis direction and a position where the column portion 42 is sandwiched in the Y-axis direction, respectively. And the buffer material 30 is provided in the site | part (end surface) of each protrusion base 24 facing the pillar part 42. As shown in FIG. With such a configuration, excessive displacement can be suppressed regardless of the vibration direction.

  As described above, the base isolation structure of the present embodiment includes the base isolation layer S having the space K having a height h from the lower structure 4 between the upper structure 2 and the lower structure 4. . The seismic isolation layer S includes a column part 42 erected from the lower structure 4 higher than the height h (at a height H), a seismic isolation device 10 provided between the upper structure 2 and the column part 42, A protruding foundation 24 that hangs down to a height h from the upper structure 2 and includes a protruding foundation 24 that is spaced apart from the column portion 42 in the horizontal direction (X-axis direction, Y-axis direction). In addition, the cushioning material 30 is provided on the protruding foundation 24 so as to abut against the column portion 42 when the upper structure 2 and the lower structure 4 are displaced relative to each other in the horizontal direction by the length c.

  As a result, it is not necessary to provide a pair of excessive displacement suppression foundations in each of the upper structure 2 and the lower structure 4, so that excessive displacement can be suppressed while reducing costs.

<First Modification>
FIG. 4 is a diagram illustrating a first modification of the seismic isolation structure according to the first embodiment. The same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The seismic isolation structure of the first modification includes a column part 421 and a protruding foundation 241.

  As shown in FIG. 4, the pillar portion 421 has a circular planar shape (planar circle). Also. The protruding foundation 241 is provided so as to integrally surround the column portion 421. The external shape (planar shape) of the protruding foundation 241 is a quadrangle, and a regular octagonal space is formed inside. And the pillar part 421 is arrange | positioned in the center of the space. In addition, the cushioning material 30 is provided on each side (side surface) of the regular octagon inside the protruding foundation 241 so as to face the column portion 421. Each buffer material 30 and the lower base 421 are separated from each other by a predetermined distance (length c). In this case as well, excessive displacement can be suppressed regardless of the direction of vibration as in the case of FIG. In this example, the inside of the protruding foundation 241 is a regular octagon, but the present invention is not limited to this. For example, it may be a regular hexagon or a regular decagon. In these cases, the buffer material 30 may be provided so as to face the column portion 421.

<Second Modification>
FIG. 5 is a diagram illustrating a second modification of the seismic isolation structure according to the first embodiment. The same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The seismic isolation structure of the second modified example includes a protruding foundation 242. The protruding foundation 242 is provided so as to integrally surround the column portion 421 similarly to the protruding foundation 241, and a circular space is formed inside. And the pillar part 421 is arrange | positioned in the center of the space. Further, the buffer material 302 is circularly arranged along the inner periphery of the protruding foundation 242, and the buffer material 302 and the column part 421 are separated from each other by a predetermined distance (length c). Even in this case, an excessive displacement can be suppressed regardless of the direction of vibration.

<Third Modification>
FIG. 6 is a diagram illustrating a third modification of the seismic isolation structure according to the first embodiment. The same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The seismic isolation structure of the third modified example includes a column portion 422.

  As shown in FIG. 6, the pillar portion 422 is a pillar member having a regular octagonal plan shape. And the protrusion foundation 24 and the shock absorbing material 30 are each provided (eight) corresponding to each eight side surfaces of the pillar part 422. As in the above-described embodiment, the length of the end face of the cushioning material 30 is a, and each cushioning material 30 and the column portion 422 are separated by a predetermined distance (length c). In this case, even if the length of each side of the column portion 422 is smaller than a + 2c (and even smaller than a), excessive deformation can be suppressed regardless of the direction of vibration.

=== Second Embodiment ===
FIG. 7 is an elevation view showing the configuration of the vibration isolation structure of the second embodiment. Parts having the same configurations as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The seismic isolation layer S of the seismic isolation structure of the second embodiment includes the damping device 16, the column part 42, the damping foundation 23, and the protruding foundation 24 (and the cushioning material 30). In the second embodiment, a damping device 16 (corresponding to a damping mechanism) is provided as a seismic isolation mechanism. Further, although not shown in the figure, in other places of the seismic isolation layer S, the base for seismic isolation 22, the column part 42, and the seismic isolation device (here, ordinary laminated rubber, etc.) are the same as in the first embodiment. ) Is provided. As a result, stigma isolation is configured.

  The damping base 23 is provided so as to protrude downward from the upper structure 2 at a position spaced apart from the column portion 42 in the horizontal direction (X-axis direction in the drawing).

  The damping device 16 is an oil damper using oil in this embodiment. The attenuation device 16 is disposed along the horizontal direction (X-axis direction), and one end of the attenuation device 16 is connected to the attenuation base 23 and the other end is connected to the column portion 42. The damping device 16 generates a damping force in accordance with the relative displacement between the damping foundation 23 and the column portion 42 (in other words, the relative displacement between the upper structure 2 and the lower structure 4).

  Thus, in the second embodiment, the damping device 16 is used as a seismic isolation mechanism. The damping device 16 is provided between the column portion 42 and the upper structure 2 (more specifically, the damping foundation 23). In this case as well, as in the first embodiment, the excessive displacement can be suppressed by providing the protruding foundation 24 (and the buffer material 30).

=== Third Embodiment ===
FIG. 8 is an elevation view showing the configuration of the vibration isolation structure of the third embodiment. Parts having the same configurations as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the third embodiment, the upper structure 2 is provided with an elevator shaft 50 (corresponding to a hanging part). The elevator shaft 50 is an elevator hoistway, and is provided so as to hang down from the upper structure 2. Further, in order to enable relative displacement between the upper structure 2 and the lower structure 4, a space K ′ having a length h ′ is provided between the lower structure 4 and the elevator shaft 50 in the Z-axis direction. That is, the seismic isolation layer S has a space K ′ having a height h ′ between the elevator shaft 50 and the lower structure 4. A cushioning material 30 is provided on the side surface of the elevator shaft 50 facing the column portion 42. The cushioning material 30 and the column part 42 are separated from each other by a predetermined distance (length c) in the X-axis direction. In addition, the elevator shaft 50 of this embodiment is reinforced so that rigidity may become higher than usual.

  Thus, when the elevator shaft 50 is displaced by the length c in the X-axis direction with respect to the column part 42 (that is, when the upper structure 2 and the lower structure 4 are displaced by the length c in the X-axis direction), the cushioning material 30 Is in contact with the column part 42. By this contact, excessive displacement can be suppressed.

  In this 3rd Embodiment, since the member (elevator shaft 50) of a building is used as a member (hanging part) of excessive displacement suppression, it is not necessary to newly provide a foundation and cost reduction can be further achieved. In addition, in this embodiment, although the elevator shaft 50 was used as a member (hanging part) for suppressing an excessive displacement, it is not restricted to this. For example, other lifting equipment (such as a staircase) or an equipment machine room may be used.

=== About Other Embodiments ===
The above embodiment is for facilitating the understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<Seismic isolation structure>
Although the seismic isolation structure of the above-mentioned embodiment was a stigma isolation, it is not limited to this. For example, it may be an intermediate layer seismic isolation system in which a seismic isolation device is provided on an intermediate floor of a building. In this case, a foundation (corresponding to a standing portion) that protrudes upward from the lower structure 4 may be provided instead of the column portion 42.

<About buffer material>
In the above-described embodiment, the cushioning material 30 is an elastic member (rubber or the like). However, the cushioning material 30 is not limited to an elastic member as long as it can reduce the impact of a collision. For example, a member that yields (plastically deforms) when the load reaches a predetermined value may be used (see FIG. 10).

  Further, in the above-described embodiment, the cushioning material 30 is provided on the hanging portion (such as the protruding foundation 24 and the elevator shaft 50) that hangs down from the upper structure 2, but may be provided on the column portion 42 side.

  Or you may make it collide (contact | abut) the pillar part 42 and the drooping part, without providing the shock absorbing material 30. FIG. In this case, any one side surface (contact surface) of the column portion 42 and the hanging portion corresponds to the contact portion.

<About the protruding foundation>
The protruding foundation 42 of the above-described embodiment has the same shape (rectangular section) from the upper end to the lower end, but is not limited thereto.

  FIG. 9 is a view showing a modified example of the protruding foundation. 9, parts having the same configurations as those in FIG.

  In FIG. 9, a projecting foundation 24 'is provided. The protruding foundation 24 ′ is constituted by, for example, a steel cross section. Specifically, the protruding foundation 24 'includes a lower portion 24a (corresponding to a first portion) including a range overlapping with the column portion 42 in the Z-axis direction (a range from height h to height H), and a lower portion 24a. And the upper part 24b (corresponding to the second part) between the upper part 2 and the upper part 2. And the lower part 24a is comprised by the cross section smaller than the upper part 24b. For this reason, the lower part 24a is easier to yield (plastic deformation) than the upper part 24b.

  Here, a member that yields (plastically deforms) when the load reaches a predetermined value is used as the buffer material 30.

  FIG. 10 is a diagram illustrating an example of restoring force characteristics of the protruding foundation 24 ′ and the buffer material 30 of FIG. 9. The horizontal axis of FIG. 10 indicates the displacement, and the vertical axis indicates the load. The displacement is indicated by the displacement from the state where no compressive force is applied. In FIG. 10, the alternate long and short dash line is the characteristic of the cushioning material 30, and the broken line is the characteristic of the protruding foundation 24 '. Moreover, the characteristic which put together the shock absorbing material 30 and the protrusion base 24 'is shown with the gray line.

  In the region where the load is small, the displacement and the load are proportional to each other in the cushioning material 30 and the protruding foundation 24 '(elastic region), and the characteristics combining the cushioning material 30 and the protruding foundation 24' (gray line in the figure) Follows the characteristics of the cushioning material 30. When the load increases and exceeds the point A in the figure, the buffer material 30 becomes a plastic region and the buffer material 30 is plastically deformed. Thereby, the characteristic which combined the shock absorbing material 30 and the protruding foundation 24 'comes to follow the characteristic (broken line) of the protruding foundation 24'. When the point B is exceeded, the lower portion 24a of the protruding foundation 24 'becomes a plastic region and yields (plastic deformation). When the protruding foundation 24 of FIG. 1 is used, the proportional relationship continues without yielding at point B (without displacement-load characteristics being bent at point B). For this reason, when it collides with the column part 42, there exists a possibility that an excessive horizontal load may be applied to the upper structure 2 or the column part 42. FIG. On the other hand, in the protruding foundation 24 ′ of this modification, the lower part 24 a is more easily plastically deformed than the upper part 24 b (plastic deformation is performed at the point B in FIG. 10). It can suppress that a load is applied.

  In this example, the upper portion 24b and the lower portion 24a of the projecting foundation 24 'are configured with a steel cross section, but the present invention is not limited to this. For example, you may comprise the upper part and lower part of the protrusion base 24 of FIG. 1 with a different material.

<Seismic isolation device>
In the above-described embodiment (the first embodiment), the laminated rubber 12 containing a lead plug (high-attenuation laminated rubber) is used as the seismic isolation device 10, but the invention is not limited thereto. For example, a high damping laminated rubber whose rubber material itself has a damping function may be used.

  Moreover, although the seismic isolation apparatus 10 of the above-mentioned embodiment was provided with the seismic isolation function, the restoration function, and the attenuation function, it is not necessary to provide all of them. For example, a normal laminated rubber (a laminated rubber having no damping function) or a rolling bearing may be used as the seismic isolation device. In this case, a damping device (such as a damper) or a restoring device (such as a spring) may be provided at another location.

Moreover, you may comprise a base isolation structure using two or more types of base isolation apparatuses.
FIG. 11 is a diagram illustrating a modification of the seismic isolation structure. Parts having the same configurations as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 11, a plurality of (three in the figure) column portions 42 and a base for seismic isolation 22 are provided in the base isolation layer S between the upper structure 2 and the lower structure 4. One of them (center in the figure) is provided with an elasto-plastic bearing isolation device 100, and the other (right and left) pillars 42 are provided with an elastic bearing isolation. A device 10 is provided. Note that the seismic isolation device 10 has a higher maximum load in the horizontal direction than the seismic isolation device 100. Further, the protruding foundation 24 and the cushioning material 30 are provided only for the central column portion 42 (the column portion 42 provided with the seismic isolation device 100).

  The middle part of FIG. 11 shows the restoring force characteristics of the column part 42 where each seismic isolation bearing (the seismic isolation device 10 and the seismic isolation device 100) is installed. The seismic isolation devices 10 on the right and left sides of the figure are elastic bearings and have the same characteristics (characteristics in which displacement and load are proportional) (gray line in the figure). On the other hand, the seismic isolation device 100 provided in the central column part 42 in the figure is an elasto-plastic bearing and has an elastic region and a plastic region. A broken line in each figure indicates a boundary value between the elastic region and the plastic region of the seismic isolation device 100. Moreover, the intersection of the horizontal axis in the characteristics of the protruding foundation 24 and the cushioning material 30 corresponds to the displacement when colliding with the column part 42.

  When the characteristics of the seismic isolation device 100 are combined with the characteristics of the protruding foundation 24 and the buffer material 30, the characteristics indicated by the black line in the lower part of FIG. That is, after the protruding foundation 24 (the shock absorbing material 30) and the seismic isolation device 100 collide, the seismic isolation device 100 becomes a plastic region, and the increase in load becomes moderate. As described above, the burden load is smaller than the load (the gray line in the figure) of the column part 42 that does not collide with the protruding foundation 24 even though the protruding foundation 24 (buffer material 30) collides with the column part 42. Become. Therefore, the maximum burden load of the column part 42 colliding with the protruding foundation 24 (the buffer material 30) can be made to be approximately the same as the maximum burden load of the column part 42 where the seismic isolation device 10 is installed, and the burden load is reduced. Can be achieved. Even if the seismic isolation device 100 yields, the upper structure 2 can be supported by the seismic isolation device 10 of elastic bearing.

  In FIG. 11, an elasto-plastic bearing is used. However, the present invention is not limited to this. For example, a rigid-plastic bearing may be used. Or it is good also as an elastic sliding bearing which combined the laminated rubber which provided the sliding material in the upper end or the lower end, and a sliding board. In this way, the seismic isolation bearing installed on the column part 42 that collides with the protruding foundation 24 and the cushioning material 30 is an elasto-plastic bearing, a rigid-plastic bearing, or an elastic sliding bearing, so that the maximum burden of the column part 42 is obtained. The load can be reduced (for example, it can be made smaller than the maximum burden load of the column portion 42 provided with the seismic isolation device 10 of the elastic bearing). In this example, the seismic isolation device 10 is an elastic bearing. However, as long as the maximum load applied in the horizontal direction is higher than that of the seismic isolation device 100, other bearings may be used.

<About the damping device>
Although the damping device 16 of the above-described embodiment (second embodiment) is an oil damper, it is not limited to this. For example, a viscous (elastic) damper or a friction damper may be used.

2 Upper structure 4 Lower structure 10, 10 'Seismic isolation device 12 Laminated rubber (high damping laminated rubber)
13a Upper flange plate 13b Lower flange plate 16 Damping device 22 Base for seismic isolation 23 Foundation for damping 24 Projection foundation (hanging part)
30 cushioning material 42 pillar part (standing part)
50 Elevator shaft (hanging part)

Claims (14)

A base isolation structure having a base isolation layer having a space of a predetermined height from the lower structure between the upper structure and the lower structure,
The seismic isolation layer is
A standing portion that is erected higher than the predetermined height from the lower structure;
A seismic isolation mechanism provided between the superstructure and the standing portion;
A hanging part that hangs down from the upper structure to the predetermined height, the hanging part spaced apart in a horizontal direction from the standing part,
An abutment provided on one of the standing portion and the hanging portion, and abutting against the other of the standing portion and the hanging portion when the upper structure and the lower structure are relatively displaced by a predetermined distance in the horizontal direction. And
A seismic isolation structure characterized by comprising. The seismic isolation structure according to claim 1,
The contact portion includes a cushioning material,
Seismic isolation structure characterized by that. The seismic isolation structure according to claim 1 or 2,
When the predetermined distance is c, and the length of the contact portion in the horizontal width direction orthogonal to the horizontal direction is a,
The length of the other of the standing portion and the hanging portion in the horizontal width direction is (a) from the position corresponding to the center of the contact portion in the horizontal width direction to one side and the other side in the horizontal width direction. / 2 + c) or more,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 3,
The standing portion is a planar polygonal columnar body, and the hanging portion is provided on a side of each side surface of the columnar body.
Seismic isolation structure characterized by that. The seismic isolation structure according to claim 1 or claim 2,
The standing portion is a planar circular columnar body, and the hanging portion is provided on a side of the periphery of the columnar body,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 5,
The hanging part integrally surrounds the standing part,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 6,
The predetermined height is 2.1 m or more.
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 7,
The hanging part is
A first portion including a range from the predetermined height to the height of the standing portion;
A second site between the first site and the superstructure;
Have
The seismic isolation structure, wherein the first part is more easily plastically deformed than the second part. A seismic isolation structure according to any one of claims 1 to 6,
The hanging part is a lifting equipment hanging from the superstructure, or a machine equipment room,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 9,
The seismic isolation mechanism is a highly damped laminated rubber,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 9,
The seismic isolation mechanism is an elasto-plastic bearing, a rigid-plastic bearing, or an elastic sliding bearing.
Seismic isolation structure characterized by that. The seismic isolation structure according to claim 11,
The seismic isolation layer includes a plurality of the standing portions,
The seismic isolation mechanism, the hanging part, and the contact part are provided with respect to a certain standing part,
A seismic isolation mechanism having a high maximum load to be borne in the horizontal direction compared to the seismic isolation mechanism is provided between the other standing part and the superstructure,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 9,
The seismic isolation mechanism is a restoration mechanism,
Seismic isolation structure characterized by that. A seismic isolation structure according to any one of claims 1 to 9,
The seismic isolation mechanism is a damping mechanism,
Seismic isolation structure characterized by that.