JP5180240B2 - Seismic isolation structure - Google Patents

Description

  The present invention relates to a seismic isolation device suitable for interposing between upper and lower structures on which a tensile force acts particularly during an earthquake.

  In various types of structures, in order to ensure safety in the event of an earthquake, by installing seismic isolation devices on the foundations and intermediate floors of the structure, the earthquake will attempt to propagate from the lower structure to the upper structure. Various seismic isolation methods that reduce vibrations and suppress stresses and deformations that occur in the superstructure frame are used.

  FIG. 4 shows a seismic isolation structure using a general seismic isolation method, in which a seismic isolation device 3 using laminated rubber is interposed between an upper structure 1 and a lower structure 2.

  Here, the seismic isolation device 3 has upper and lower flanges 4 and 5 fixed to upper and lower ends of a seismic isolation member 6 in which thin steel plates and rubber sheets are bonded and integrated in a laminated manner. An outer peripheral portion of the flange 4 is attached to a mounting plate 1 a integrated with the lower surface of the upper structure 1 by bolts 7, and an outer peripheral portion of the lower flange 5 is mounted on an installation plate 2 a integrated with the upper surface of the lower structure 2 by bolts 8. It is attached.

  According to such a seismic isolation device 3, during normal times, the load of the upper structure 1 can be supported on the lower structure 2 by the seismic isolation member 6 that is laminated and integrated. Is elastically deformed in the horizontal direction, so that the seismic force acting on the upper structure 1 can be reduced.

By the way, the conventional seismic isolation device is designed on the assumption that a vertical load is always applied from the upper structure 1 in both a normal time and an earthquake.
On the other hand, regardless of whether the superstructure 1 in which the seismic isolation device 3 is installed is a high layer, the aspect ratio (tower ratio) is large, or the shape of the building, the vertical motion component of the earthquake motion is large. In some cases, when an earthquake occurs, it is assumed that a location where a tensile force acts on the seismic isolation device 3 as indicated by an arrow in the figure occurs.

  And in the seismic isolation apparatus 3 installed in such a place, in addition to the stress concentration by the characteristic of the seismic isolation member 6 itself, as shown in FIG. Further stress concentration occurs in the vicinity of the joint between the upper and lower flanges 4 and 5 of FIG. 6, and as a result, the tensile properties of the seismic isolation member 6 may be reduced when an earthquake occurs.

  Therefore, in the following Patent Document 1, for example, a groove is formed on the surface of the upper and lower flanges between the seismic isolation member and the bolt to reduce the rigidity of the upper and lower flanges. A rubber laminated structure for seismic isolation has been proposed in which the stress concentration on the end of the laminated rubber is reduced.

Japanese Patent Laid-Open No. 10-38024

  However, in the conventional seismic isolation structure using the rubber laminated structure, since the rigidity of the upper and lower flanges is reduced by the groove, if the groove is formed too deep, a large-scale earthquake occurs. If the upper and lower flanges are damaged, and if the groove is too shallow, the desired stress concentration mitigation effect cannot be obtained at the time of a small-to-medium-scale earthquake, and thus the groove is difficult to design.

  The present invention has been made in view of the above circumstances, and the seismic isolation structure that can stably exhibit the seismic isolation effect even if it is interposed in a place where a tensile force acts between the upper and lower structures during an earthquake. Is intended to provide.

In order to solve the above-mentioned problem, the invention according to claim 1 is provided such that a seismic isolation device in which a flange is integrated with the upper and lower end portions of the seismic isolation member is interposed between the upper and lower structures, and each of the flanges is described above. In the seismic isolation structure attached to the upper and lower structures, either one of the flange and the upper and lower structures is a linear groove that passes through the central portion of the flange or the portion facing the flange and reaches the outer peripheral portion. On the other hand, a convex portion that can be inserted into the groove portion from the horizontal direction is formed, and an engaging portion that prevents displacement in the vertical direction is formed between the groove portion and the convex portion. It is characterized by that.

According to the first aspect of the present invention, since the flange of the seismic isolation device is fixed to the upper and lower structure at the central portion of the surface facing the upper and lower structure, the seismic isolation device is attached to the seismic isolation device during an earthquake. Even when a tensile force is applied, it is possible to reliably prevent stress concentration from occurring in the vicinity of the joint between the seismic isolation member and the flange due to deformation of the outer periphery of the flange. The seismic effect can be demonstrated.

In addition , a linear groove portion that passes through the central portion of the flange or the portion facing the flange and reaches the outer peripheral portion is formed in either one of the flange and the upper and lower structure, and on the other side, the groove portion from the horizontal direction is formed. In addition to forming an insertable convex portion and forming an engaging portion between these groove portions and the convex portion to prevent mutual displacement in the vertical direction, the other convex shape is formed in one groove portion. By inserting the portions and engaging the engaging portions with each other, the flange can be easily attached to a metal installation plate or the like.

  Also, when it is necessary to remove the seismic isolation device for some reason such as aging after installation, for example, a temporary jack is installed between the upper and lower structures to support the load of the upper structure Later, by removing the bolts between the upper and lower flanges and the upper and lower structures, and then releasing the engagement portion, the seismic isolation device is moved in the horizontal direction, and the convex portion is extracted from the groove portion. The seismic isolation device can be easily replaced or repaired.

It is a longitudinal cross-sectional view of the attachment part of the seismic isolation apparatus which shows one Embodiment of the seismic isolation structure which concerns on this invention. FIG. 2 shows the shape of the upper flange in FIG. 1, (a) is a plan view, and (b) is a front view. It is a front view which shows the state which mutually released the engagement part, when removing the seismic isolation apparatus of FIG. 1 once. It is a front view which shows the conventional seismic isolation structure. It is the perspective view which looked at the longitudinal cross-section which shows the deformation | transformation state when tensile force acts on the seismic isolation apparatus of FIG.

  1 to 3 show an embodiment of a seismic isolation structure according to the present invention. This seismic isolation structure includes an installation plate (upper structure) 10 fixed to the lower surface side of the upper structure 1 and a lower part. A seismic isolation device 12 is interposed between an installation plate (lower structure) 11 fixed on the upper surface side of the structure 2, and is schematically configured.

  Here, in the seismic isolation device 12, disc-shaped upper and lower flanges 14, 15 each having a larger diameter than the seismic isolation member 13 are integrally provided on upper and lower ends of the seismic isolation member 13 having a substantially external appearance. The seismic isolation member 13 is constituted by a laminated rubber in which a plurality of metal plates and a rubber sheet are bonded on both sides and integrated in a laminated shape.

Grooves 16 and 17 are formed on a surface 14a of the upper flange 14 facing the mounting plate 10 and a surface 15a of the lower flange 15 facing the mounting plate 11, respectively.
The configuration of the groove 16 will be described with reference to FIG. 2 showing the shape of the upper flange 14. The groove 16 is linearly formed along its diameter line so as to open on the facing surface 14a of the upper flange 14. Is formed.

The groove 16 is formed in an L-shaped cross section having a bottom width W ₂ wider than the width W ₁ of the opening. As a result, a widened engaging recess 16 a is formed in the lower portion of the groove 16. The groove portion 17 formed on the facing surface 15a of the lower flange 15 is formed symmetrically with the groove portion 16 with respect to the horizontal line, and thus the bottom portion of the groove 17 is similarly widened. A recess 17a is formed.

  On the other hand, convex portions 18 and 19 inserted into the groove portions 16 and 17 are integrally formed on the lower surface of the installation plate 10 facing the groove portions 16 and 17 and the upper surface of the installation plate 11, respectively.

Here, the convex portions 18 and 19 are engaged with the convex portions protruding from the surfaces of the mounting plates 10 and 11 and the engaging concave portions 16a and 17a extending in the horizontal direction from the tips of the convex portions. Rukakarigototsu portion 18a, the engaging projection 18a at one formed in an L-shape by the 19a, the width dimension of the 19a, than the width W ₁ of the opening portion of the groove 16, 17 is slightly smaller ing.

  In order to install the seismic isolation device 12 having the above-described configuration on the installation plate 11 fixed to the lower structure 2, first, from the opening of the groove portion 17 of the lower flange 15, the engagement convex portion of the convex portion 19 of the installation plate 11. 19 a is inserted and the convex portion 19 is accommodated in the groove portion 17. Next, the seismic isolation device 12 is moved in the horizontal direction to insert the engaging convex portion 19 a of the convex portion 19 into the engaging concave portion 17 a of the groove portion 17.

  Thereby, the seismic isolation device 12 is attached to the installation plate 11 in a state in which upward displacement is prevented. Then, the lower flange 15 of the seismic isolation device 12 is fixed to the installation plate 11 with the bolt 20, whereby the installation of the seismic isolation device 12 on the installation plate 11 is completed.

  Further, when the installation plate 10 is attached to the upper flange 14 of the seismic isolation device 12, the engagement convex portion 18 a of the convex portion 18 of the installation plate 10 is similarly formed from the opening of the groove portion 16 of the upper flange 14. The convex portion 18 is inserted into the groove portion 16 by insertion. Next, by moving the installation plate 10 in the horizontal direction, the engaging convex portion 18 a of the convex portion 18 is inserted into the engaging concave portion 16 a of the groove portion 16.

  Next, the installation plate 10 is attached to the upper flange 14 of the seismic isolation device 12 by fixing the upper flange 14 of the seismic isolation device 12 to the installation plate 10 with bolts 20. Then, the seismic isolation device 12 is attached between the upper and lower structures by integrating the installation plate 10 into the upper structure 1 which is separately constructed by studs, anchors 21 or the like.

  Further, when it is necessary to remove the seismic isolation device after installation for some reason such as aging deterioration, a temporary hydraulic jack 22 is first installed between the installation plates 10 and 11, for example, as shown in FIG. These hydraulic jacks 22 transmit the load of the upper structure 1 to the lower structure 2.

  Next, after removing the bolt 20 that has fixed the seismic isolation device 12, the seismic isolation device 12 is horizontally moved in a direction orthogonal to the groove portions 16 and 17, and the engagement recesses 16a and 17a are moved as shown in FIG. The engagement state between the engagement projections 18a and 19a is released. The seismic isolation device 12 can be removed from between the installation plates 10 and 11 by moving the seismic isolation device 12 in the horizontal direction along the groove portions 16 and 17. This makes it possible to easily replace or repair the seismic isolation device 12 while minimizing the height and range of jacking up.

  As described above, according to the seismic isolation structure configured as described above, the grooves 16 and 17 extending in the diametrical direction including the central portion are formed on the opposing surfaces 14a and 15a of the upper and lower flanges 14 and 15, The convex portions 18 and 19 projecting from the installation plates 10 and 11 are inserted into the groove portions 16 and 17, and the engagement convex portions 18 and 19 are inserted into the engagement concave portions 16 a and 17 a of the groove portions 16 and 17. By engaging the portions 18a and 19a, the central portions of the upper and lower flanges 14 and 15 are also fixed so as not to move up and down relatively with respect to the installation plates 10 and 11. Even when a tensile force acts on 12, the outer peripheral portions of the upper and lower flanges 14 and 15 are not deformed.

  As a result, it is possible to reliably prevent stress concentration from occurring near the joint between the seismic isolation member 13 and the upper and lower flanges 14 and 15, and thus to stably exhibit the seismic isolation effect.

  In the above embodiment, the groove portions 16 and 17 are formed on the upper and lower flanges 14 and 15 side, and the convex portions 18 and 19 inserted into the groove portions 16 and 17 are formed on the installation plate 10 and 11 side. Although the case has been described, the present invention is not limited thereto, and conversely, the convex portions 18 and 19 may be formed on the upper and lower flanges 14 and 15 side, and the groove portions 16 and 17 may be formed on the installation plate 10 and 11 side.

  Furthermore, the present invention is not limited to these groove portions and convex portions, and various forms such as anchors are adopted as long as the upper and lower flanges can be fixed to the upper and lower structures facing each other at the central portion. It is possible.

  Further, the seismic isolation member 6 is not limited to the laminated rubber described above, and can be applied to members that exhibit various seismic isolation effects.

1 Upper structure 2 Lower structure 10 Installation plate (upper structure)
11 Installation plate (under structure)
12 Seismic Isolation Device 13 Seismic Isolation Member 14 Upper Flange 15 Lower Flange 16, 17 Groove 16a, 17a Engaging Recess 18, 19 Convex 18a, 19a Engaging Protrusion

Claims (1)

Between the upper and lower structures, a seismic isolation device in which flanges are integrated at the upper and lower ends of the seismic isolation member is interposed, and the flanges are respectively attached to the upper and lower structures,
Either one of the flange and the upper and lower structure is formed with a linear groove portion that passes through the central portion of the flange or a portion facing the flange and reaches the outer peripheral portion, and is inserted into the groove portion from the horizontal direction on the other side. A seismic isolation structure characterized in that a possible convex portion is formed and an engaging portion is formed between the groove portion and the convex portion to prevent mutual displacement in the vertical direction .

Images