JP2018188889A - Base-isolated structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base-isolated structure that can reduce direction dependency of attenuating force of respective dampers and torsional response of an upper structure simultaneously.SOLUTION: In a base-isolated structure, an upper structure is supported by seismic isolators 2 on an understructure 1 and plural dampers 4 are interposed between the upper structure and the understructure in the horizontal direction. The dampers 4 are disposed to direct the actuation direction toward the X-Y direction between the corner parts C where X-Y direction beams of the upper structure are crossed. On the corner parts C, the dampers 4 are disposed so as to incline the actuation direction with respect to the X-Y direction, and one end part of the damper 4 is connected to a mount 6 provided in the X direction at one of the upper structure and the understructure and other end part is connected to a mount 7 provided in the Y direction at the other of the upper structure and the understructure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a seismic isolation structure in which an upper structure is supported by a seismic isolation device on a lower structure, and a damping damper is horizontally interposed between the upper and lower structures.

  In recent years, in order to ensure the safety of structures against earthquakes, a seismic isolation layer is formed on the lower structure with a base rubber isolation device using laminated rubber and sliding bearings. Various seismic isolation structures have been constructed that dampen the vibrations to be propagated in the interior and further dampen the vibrations by placing a damper such as an oil damper in the horizontal direction between the upper and lower structures.

  Among such seismic isolation structures, in general RC seismic isolation buildings, as shown in FIG. 7, between the foundation (lower structure) 21 and the beam under the pillar of the building (upper structure). The seismic isolation device 22 is installed on the XY plane at intervals, and a plurality (eight in the figure) of oil dampers 23 are installed on the outer periphery of the building in the X and Y directions along the beam. Has been.

  By the way, in the conventional seismic isolation building, since the oil damper 23 is arranged in the XY direction along the beam, the dependency of the damping force on the XY direction increases, and the XY There is a problem in that the damping force becomes excessive and the response characteristics are deteriorated with respect to the shaking in the direction of 45 degrees and 135 degrees in the direction.

  Therefore, in the following Patent Document 1, as shown in FIG. 8, in a detached house, a large number of seismic isolation bearings 32 using ball bearings are placed on the building foundation (lower structure) 31. The seismic isolation bearing 32 slidably supports the steel floor beam on which the upper building (upper structure) is placed, and has one end coupled to the steel floor beam and the other end coupled to the building foundation 31 (4 in the figure). A seismic isolation structure has been proposed in which horizontal oil dampers 33a to 33d are arranged in four directions different from each other by 45 degrees in a plane.

  According to the base-isolated house having the above-described configuration, the oil dampers 33a to 33d are arranged in four directions different from each other by 45 degrees, and therefore the direction dependency on the damping force transmitted to the upper building. Therefore, it is possible to protect the detached house from a large earthquake.

JP 2005-036490 A

  However, the seismic isolation structure described in Patent Document 1 is easy to apply to detached houses and the like, but for large and high-rise structures such as commercial buildings and apartment buildings, In addition, due to the structure of the beam, there is a problem that it is difficult to install the oil dampers 33c and 33d so as to be inclined with respect to the XY direction in which the beam extends.

  In addition, since the oil dampers 33c and 33d are arranged with their strokes toward the center (center of gravity) of the upper building, the torsional response of the upper building that occurs during an earthquake is reduced by the entire oil dampers 33a to 33d. There was also a problem that the effect to do becomes small.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the seismic isolation structure which can reduce both the direction dependence of the damping force by a damper, and the torsional response of an upper structure. Is.

  In order to solve the above problems, the invention according to claim 1 is characterized in that the upper structure is supported on the lower structure by a seismic isolation device, and a plurality of dampers are horizontally interposed between the upper and lower structures. In the seismic isolation structure, the damper is disposed with the operating direction in the XY direction between the corners where the beams in the XY direction of the superstructure intersect, and in the corners. Is arranged with the operation direction inclined with respect to the XY direction, and one end of the damper is connected to one of the upper and lower structure mounting bases in the X direction and the other end is connected to the upper and lower sides. It is connected to a mounting base provided in the other Y direction of the partial structure.

  According to a second aspect of the present invention, in the first aspect of the invention, each of the mounting bases at the corners has a side surface along the XY direction, and the two dampers are mounted on the mounting surface. The corners of the base are arranged in parallel with each other, and one end of one of the dampers is connected to a side surface of the mounting base in the X direction along the X direction, and the other end is connected in the Y direction. The mounting base is connected to the side surface along the Y direction, the other end of the damper is connected to the side surface along the Y direction of the mounting base in the X direction, and the other end is connected to the mounting base in the Y direction. It is connected to the side surface along the X direction.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the mounting base at the corner is a mounting base for the seismic isolation device and is provided in the X direction of the lower structure. Further, the damper is installed horizontally by forming one of the mounting base and the mounting base provided in the Y direction to be larger in height than the other. .

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the dampers are respectively provided at the four corners of the upper and lower structure constructed in a substantially square shape in plan view. It is arranged to be inclined by 45 degrees with respect to the XY direction.

  According to the invention described in any one of claims 1 to 4, a plurality of dampers are disposed along the XY direction in which the superstructure beam extends, and the beam in the XY direction is further provided. At the intersecting corners, the dampers are inclined with respect to the XY direction, so that the dampers disposed in the XY directions are attenuated by the dampers disposed in the corners. The direction dependency of force can be reduced.

  In addition, the dampers arranged at the corners have a greater distance to the center (center of gravity) of the structure perpendicular to the operating direction than other dampers, so that the torsional response of the superstructure is effectively suppressed. Therefore, the torsional response of the upper structure can be further reduced as compared with the conventional seismic isolation structure in which the damper is disposed only in the XY direction.

  Furthermore, in high-rise apartments, etc., pillars are not provided at the corners, and the corners often have short spans supported by cantilever beams. Conventionally, dampers are placed along the beams in the spans. However, according to the present invention, since the damper is inclined and arranged between the beam in the X direction and the beam in the Y direction, even in the corner portion of such a short span. It is possible to install easily.

  According to the invention of claim 2, for example, when the mounting base is formed in a columnar shape having side surfaces along the XY direction in accordance with the column beam surface, the X side surface and the Y side are formed at the corners. Since the two dampers are arranged in parallel to each other with the corner between the side surfaces interposed therebetween, it is possible to prevent torsional stress from acting on the mounting base.

  Furthermore, as in the invention described in claim 3, the mounting base of the seismic isolation device is used as the mounting base, and the mounting base provided on the X-direction beam of the lower structure and the mounting base provided on the Y-direction beam If the height of one of them is made larger than the other and the damper is installed horizontally, the seismic isolation device and damper can be installed compactly even at the short corners of the span described above. It becomes possible.

  And like invention of Claim 4, a damper is made to incline 45 degree | times with respect to the said XY direction at the four said corners of the upper-lower part structure constructed | assembled squarely in planar view, respectively. If it arrange | positions, the effect mentioned above can be acquired most notably, and it is suitable.

It is a plane layout view of a damper in one embodiment of the present invention. It is a front view which shows the attachment structure of the damper arrange | positioned along the XY direction in the said embodiment. It is a top view which shows the attachment structure of the damper arrange | positioned in the corner part in the said embodiment. FIG. 4 is a front view of FIG. 3. It is a top view which shows the state at the time of attaching the edge part of the damper of a corner corner to the X surface or Y surface of a mounting base. It is a top view which shows the state at the time of attaching the edge part of the damper of a corner corner to the corner | angular part of a mounting base. It is a plane arrangement view of a tamper in a conventional general seismic isolation structure. It is a plane arrangement view of a damper in a conventional detached house.

  1 to 4 show an embodiment of a seismic isolation structure according to the present invention. This seismic isolation structure is formed on a foundation (substructure) 1 constructed in a substantially rectangular shape in plan view. An upper structure beam 3 is supported by a seismic isolation device 2 made of laminated rubber, and a plurality of oil dampers 4 are interposed between the foundation 1 and the upper structure beam 3 in the horizontal direction.

  Here, at an intermediate position between the corner corner C where the beam 3 in the XY direction of the superstructure intersects and the corner corner C adjacent to each other, as shown in FIG. 2, the oil damper 4 is in the XY direction. The one end is connected to a mounting base 10 constructed on the foundation 1 and the other end is connected to a mounting base 11 suspended from the lower surface of the beam 3. .

  On the other hand, as shown in FIGS. 3 and 4, the corner portion C is disposed with the operation direction inclined with respect to the XY direction. Incidentally, in this seismic isolation structure, no pillar is provided at the corner C, and as a result, the corner C has a short span of about 3 to 4 m supported by a cantilever.

  Then, the pillar 5 in the vicinity of the corner portion C is cut to form attachment portions 6 and 7 at the cut portion, and the seismic isolation device 2 is attached between the attachment portions 6 and 7. Here, the column 5 connected to the beam 3 in the X direction is lower in the cutting position of the column 5 than the column 5 connected to the beam 3 in the Y direction. The height dimension of the mounting base 7 is larger than the height dimension of the mounting base 7 provided in the X direction.

  Moreover, the attachment parts 6 and 7 are formed in the cross-sectional square which follows the surface of the pillar 5, and the upper attachment part 6 of the seismic isolation apparatus 2 provided in the X direction and the seismic isolation apparatus 2 provided in the Y direction. The two oil dampers 4 are horizontally disposed between the lower mounting portion 7 and the mounting portion 7.

  As shown in FIG. 3, these two oil dampers 4 are inclined by 45 degrees with respect to the XY direction, and are parallel to each other with the corners 6c and 7c of the mounting bases 6 and 7 interposed therebetween. In addition to being arranged, an end (one end) 8a on one side of the oil damper 4 is connected to a side surface 6a along the X direction of the mounting base in the X direction, and an end (the other end) on the cylinder side. 9a is connected to the side surface 7b along the Y direction of the mounting base 7 in the Y direction.

  The piston rod side end (one end) 8b of the other oil damper 4 is connected to the side surface 6b along the Y direction of the X-direction mounting base 6, and the cylinder side end (other end) 9b is Are connected to the side surface 7a along the X direction of the mounting base 7 in the Y direction.

  According to the seismic isolation structure having the above-described structure, the plurality of dampers 4 are disposed along the XY direction in which the superstructure beam 3 extends between the corners C, and the corners In C, since it is inclined by 45 degrees with respect to the XY direction, it is attenuated by the oil damper 4 arranged in the XY direction by the oil damper 4 arranged in the corner C. The direction dependency of force can be effectively reduced.

In addition, as shown in FIG. 1, the oil damper 4 disposed at the corner C has a distance L from the corner C to the center (center of gravity) of the structure perpendicular to the operation direction. Since it is larger than the distance L ₁ to the oil damper 4 arranged in the Y direction (L> L ₁ ), the torsional response of the upper structure can be effectively suppressed. As a result, the torsional response of the upper structure can be further reduced as compared with the conventional seismic isolation structure in which the oil damper 4 is disposed only in the XY direction.

  Furthermore, even when the corner C has a short cantilever span as a result of the pillars not being provided at the corner C, the oil damper 4 is disposed with an inclination of 45 degrees with respect to the XY direction. Therefore, it can be installed easily.

  By the way, in general, the bases 6 and 7 of the seismic isolation device 2 and the oil damper 4 are formed in a column shape having side surfaces along the XY direction in accordance with the column beam surface. In this case, as shown in FIG. 5, at the corner C, one oil damper is attached to the side surface 7a in the X direction of one mounting base 7 and the side surface in the Y direction of the other mounting base 6 (not shown). If it is installed between 6b, torsional stress will act on the mounting bases 6 and 7 when the oil damper 4 is operated.

  Therefore, as shown in FIG. 6, if the oil damper 4 is installed between the corners 6c and 7c of the mounts 6 and 7, torsional stress is prevented from acting on the mounts 6 and 7 during the operation. However, it is necessary to separately form the mounting base 15 from the corners 6c, 7c to the side surfaces 6a, 6b, 7a, 7b, and much trouble is required for installation of the mounting base 15 and angle adjustment of the end face 15a. The problem of requiring skill arises.

  In this regard, according to the seismic isolation structure of the present embodiment, in the corner portion C, the two oil dampers 4 are opposed to each other with the corner portions 6c and 7c of the mounting bases 6 and 7 interposed therebetween. Are arranged in parallel with each other between the side surfaces 6a and 7a along the Y direction and the side surfaces 6b and 7b along the Y direction.

  Moreover, since the two oil dampers 4 are arranged, a small one can be used as one oil damper. Therefore, even in the case where the corner C having no column is a short span, It can be installed very easily.

  Furthermore, as shown in FIG. 4, while installing the oil damper 4 in the corner | angular part C between the mounting bases 6 and 7 of the seismic isolation apparatus 2, the height dimension of the mounting base 7 provided in the Y direction is set to the X direction. The two oil dampers 4 can be installed horizontally because they are larger than the height dimension of the mounting base 7 provided at.

  In addition, in the said embodiment, although demonstrated only about the case where the oil damper 4 of the corner part C was installed between the mounting bases 6 and 7 of the seismic isolation apparatus 2, this invention is not limited to this. Also in the corner portion C, similarly to the oil damper 4 between the corner portions C shown in FIG. 2, separate mounting bases 10 and 11 may be provided and installed between the mounting bases 10 and 11.

1 Foundation (substructure)
2 Seismic isolation device 3 Superstructure beam 4 Oil damper 6, 7 Mounting base 6a, 7a Side surface along X direction 6b, 7b Side surface along Y direction C Corner corner

Claims (4)

In the seismic isolation structure in which the upper structure is supported by the seismic isolation device on the lower structure and a plurality of dampers are interposed in the horizontal direction between the upper and lower structures,
The damper is disposed with the operating direction in the XY direction between the corners where the beams in the XY direction of the superstructure intersect, and the XY direction in the corners. The one end of the damper is connected to a mounting base provided in one X direction of the upper and lower structure and the other end is connected to the other of the upper and lower structure. A seismic isolation structure characterized by being connected to a mounting base provided in the Y direction.   The mounts at the corners each have side surfaces along the XY direction, and the two dampers are arranged in parallel with each other with the corners of the mounts in between. One end of the damper is connected to the side surface along the X direction of the mounting base in the X direction, and the other end is connected to the side surface along the Y direction of the mounting base in the Y direction. 2. One end of the X-direction mounting base is connected to a side surface of the mounting base in the X direction along the Y direction, and the other end is connected to a side surface of the mounting base in the Y direction along the X direction. The seismic isolation structure described in 1.   The mounting base at the corner is the mounting base for the seismic isolation device, and the height of one of the mounting base provided in the X direction and the mounting base provided in the Y direction of the lower structure. The seismic isolation structure according to claim 1 or 2, wherein the damper is installed horizontally by forming a height dimension larger than the other height dimension.   2. The dampers are disposed at four angular corners of the upper and lower structure constructed in a substantially rectangular shape in plan view so as to be inclined by 45 degrees with respect to the XY direction, respectively. The seismic isolation structure according to any one of 3 to 3.

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