JP2008121328A - Three-dimensional base isolation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the imbalance between supporting forces in the horizontal direction and the vertical direction of a three-dimensional base isolation device. <P>SOLUTION: Single laminated rubber 3 or a sliding support, or an elastic sliding support as a horizontal base isolation mechanism and a plurality of air springs 4 as a vertical base isolation mechanism are integrated with each other through the medium of a frame 5 having high rigidity. The air spring has a vibration damping function by an auxiliary tank 4b and an orifice 4c, and the three-dimensional base isolation device is provided with a vertical vibration damping mechanism 6 used for damping the vibration in the vertical direction of the air spring. Then the three-dimensional base isolation device is provided with a horizontal deformation restraint mechanism 7 which restraints deformation of the air spring in the horizontal direction while permitting vibration of the air spring in the vertical direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a three-dimensional seismic isolation device that obtains a seismic isolation effect for both horizontal and vertical vibrations of a building.

As this type of three-dimensional seismic isolation device, for example, as shown in Patent Documents 1 to 3, a laminated rubber as a horizontal seismic isolation mechanism and an air spring as a vertical seismic isolation mechanism are connected in series in the vertical direction and integrated. A generalized structure is generally used.
In particular, the three-dimensional seismic isolation device disclosed in Patent Document 3 uses a rolling seal type air spring as a vertical seismic isolation mechanism, and an auxiliary tank communicates with an air chamber defined by a diaphragm via an orifice. With this configuration, a vertical damping effect is obtained by the air flow resistance at the orifice during vibration, and it is suitable, for example, as a base that supports a large-scale building such as a nuclear power plant.
JP-A-8-177969 JP-A-9-302984 JP 2005-16633 A

However, since the support capacity per unit area of the air spring is generally as low as 1/10 or less of the laminated rubber, in the conventional general three-dimensional seismic isolation device that simply combines them in series, the laminated rubber as a horizontal seismic isolation mechanism There is a problem that a large difference in the support capacity of the air spring as a vertical seismic isolation mechanism is unavoidable and the device scale is unbalanced.
In order to improve such an imbalance, it is necessary to sufficiently increase the operating pressure of the air spring, or to sufficiently increase the size of the air spring. Naturally, there is a limit, and due to the increase in size, there are difficulties in securing installation space and workability, and in any case, such special specification air springs are much more expensive than general-purpose ones. Significant cost increases are inevitable.
From the above, there has been a demand for an effective and appropriate improvement measure that can eliminate the imbalance between the horizontal and vertical bearing forces in this type of three-dimensional seismic isolation device.

  According to the first aspect of the present invention, the horizontal seismic isolation mechanism and the vertical seismic isolation mechanism are arranged in series in the vertical direction, and are interposed between the building as the upper structure and the lower structure that supports it, so that the horizontal of the building A three-dimensional seismic isolation device configured to obtain a seismic isolation effect against vibration in the vertical direction and the vertical direction, and a high-rigidity frame is disposed between the horizontal seismic isolation mechanism and the vertical seismic isolation mechanism, and the horizontal The seismic mechanism and the vertical seismic isolation mechanism are integrated, and the horizontal seismic isolation mechanism is composed of a single laminated rubber or a sliding bearing or an elastic sliding bearing fixed at the center position of the frame. It consists of a plurality of air springs equally arranged around the center position.

  According to a second aspect of the present invention, in the three-dimensional seismic isolation device of the first aspect, an air chamber is defined in the air spring as a vertical seismic isolation mechanism, and an auxiliary tank is attached to the air chamber. The air chamber and the auxiliary tank communicate with each other through an orifice.

  According to a third aspect of the present invention, in the three-dimensional seismic isolation device according to the first or second aspect, the vertical vibration damping mechanism for damping the vertical vibration of the air spring as the vertical seismic isolation mechanism is in parallel with the air spring. Provided, and one end of the vertical vibration damping mechanism is connected to a frame.

  According to a fourth aspect of the present invention, in the three-dimensional seismic isolation device according to any one of the first to third aspects, the horizontal deformation is allowed while allowing the vertical vibration of the air spring as the vertical seismic isolation mechanism. A horizontal deformation restraining mechanism for restraining is provided in parallel with the air spring, and one end of the horizontal deformation restraining mechanism is engaged with the frame so as to be displaceable in the vertical direction but not in the horizontal direction. To do.

  According to the first aspect of the present invention, a plurality of air springs are used as a vertical seismic isolation mechanism, and the plurality of air springs are combined with a single laminated rubber or a sliding bearing or an elastic sliding bearing as a horizontal seismic isolation mechanism. Therefore, even if the support force by each air spring is insufficient, sufficient support force can be secured for the plurality of air springs as a whole, and the vertical support force can be increased by increasing or decreasing the number of air springs. Can be set freely and widely, and accordingly, the supporting force of the vertical seismic isolation mechanism can be appropriately balanced with the supporting force of the horizontal seismic isolation mechanism. As a result, it is possible to easily eliminate the imbalance between the support force of the laminated rubber and the air spring, which has been a problem in this type of general three-dimensional seismic isolation device. Therefore, a sufficient improvement effect can be obtained at low cost.

  According to the second aspect of the invention, since the air spring has a vibration damping function by the auxiliary tank and the orifice, the vibration damping function in the vertical direction is naturally and sufficiently obtained by the air spring itself.

  According to the third aspect of the present invention, since the vertical vibration damping mechanism is provided in parallel with the air spring, the vibration damping effect in the vertical direction can be sufficiently obtained even when the vibration damping function by the air spring itself is not sufficient.

  According to the invention described in claim 4, since the horizontal deformation restraining mechanism for restraining the horizontal deformation of the air spring is provided, it is possible to prevent unnecessary horizontal force from acting on the air spring and to ensure the vertical seismic isolation effect by the air spring. In addition, it is possible to reliably prevent buckling and damage of the air spring.

  1 to 2 show a three-dimensional seismic isolation device according to an embodiment of the present invention. This is interposed between the bottom surface of the building 1 as the upper structure and the upper surface of the foundation 2 as the lower structure that supports it, so that the entire building 1 is supported by seismic isolation. This is to obtain a seismic isolation effect for both vertical vibrations.

  The three-dimensional seismic isolation device of the present embodiment combines a laminated rubber 3 as a horizontal seismic isolation mechanism and an air spring 4 as a vertical seismic isolation mechanism in the same manner as a conventional general three-dimensional seismic isolation device. However, in the present embodiment, a configuration in which a single laminated rubber and a single air spring are simply directly connected is generally used, whereas in the present embodiment, a highly rigid frame 5 is sandwiched. A single laminated rubber 3 and a plurality (four in the illustrated example) of air springs 4 are arranged on the upper and lower sides thereof, and the laminated rubber 3 and the air springs 4 are fixed to the frame 5, respectively. Thus, the laminated rubber 3 and the air springs 4 are integrated.

  As shown in FIG. 1 (a), the frame 5 in this embodiment is formed by crossing a steel material 5a such as a H-section steel having a small cross section in a cross shape and integrally welding reinforcing steel plates 5b on the upper and lower sides thereof. As a whole, it has a substantially square disk shape with four corners cut off, and has sufficient rigidity to support the building 1 together with the laminated rubber 3 and the air springs 4.

  Then, as shown in FIG. 1B, the laminated rubber 3 is disposed at the center of the upper surface of the frame 5, that is, at the position where the both steel members 5a intersect, and the base plate is anchor bolts or the like with respect to the frame 5. The top plate of the laminated rubber 3 is fixed to the bottom surface of the building 1.

  Further, the air springs 4 are arranged on the lower surface side of the frame 5 at the positions of the end portions of the respective steel materials 5a. As shown in FIG. 1B, each air spring 4 is composed of a rubber bellows 4a having an internal space defined as an air chamber, and an auxiliary tank 4b integrally connected to a lower portion of the rubber bellows 4a. The upper part of the rubber bellows 4a is fixed to the lower surface of the frame 5, and the lower part of the auxiliary tank 4b is fixed to the foundation 2 with anchor bolts or the like.

  The air chamber of the rubber bellows 4a constituting the air spring 4 and the internal space of the auxiliary tank 4b communicate with each other through the orifice 4c, and when the rubber bellows 4a vibrates in the vertical direction and elastically deforms, Air flows through the orifice 4c between the air chamber, which is an internal space, and the auxiliary tank 4b, and the vibration of the rubber bellows 4a is quickly damped by the flow resistance generated at that time. That is, the air spring 4 itself has a vibration damping function and can exhibit not only a vertical seismic isolation effect but also an excellent damping effect.

  In addition, a vertical vibration damping mechanism 6 such as an oil damper is installed in parallel with the air spring 4 at the center position on the lower surface side of the frame 5, its upper end is connected to the frame 5, and its lower end is the foundation 2. To be connected to. The vertical vibration damping mechanism 6 may be supplementarily added to secure a desired amount of damping when the above-described vibration damping function of the air spring 4 itself is insufficient, and the air spring 4 itself is sufficient. If the vibration damping function can be ensured, it can be omitted. Of course, depending on the required damping performance, the vertical vibration damping mechanism 6 is not limited to the oil damper, and an appropriate type of damper may be adopted. Is also optional.

Further, on the lower surface side of the frame 5, a plurality (four in the illustrated example) of horizontal deformation restraining mechanisms 7 are provided in parallel with the air spring 4 around the center position. These horizontal deformation restraining mechanisms 7 restrain the relative displacement in the horizontal direction while allowing the relative displacement in the vertical direction of the frame 5 with respect to the foundation 2, so that the air spring 4 can be operated without hindrance and the vertical seismic isolation effect. It is installed so that unnecessary horizontal force does not act on the air spring 4 while ensuring the above.
That is, in the absence of such a horizontal deformation restraining mechanism 7, when the building 1 vibrates in the horizontal direction, the horizontal force is directly transmitted to the air spring 4 via the laminated rubber 3 and the frame 5. Therefore, unnecessary horizontal force acts on the air spring 4 to cause unnecessary deformation in the lateral direction, which not only adversely affects the seismic isolation effect in the original vertical direction, but also the rubber bellows 4a is buckled or damaged. Therefore, such a situation is avoided by installing the horizontal deformation restraining mechanism 7.

  Specifically, in the horizontal deformation restraining mechanism 7 in the present embodiment, a column 7a made of a high-rigidity steel rod is erected on the foundation 2 by a base member 7b, and a cylindrical sleeve member is formed at the upper end of the column 7a. 7c is slidably mounted in the vertical direction, and a ring-shaped bearing 7d for reducing sliding resistance with respect to the column 7a is attached to the inside of the sleeve member 7c. . Then, by fixing the sleeve member 7c around the center position of the frame 5 (around the crossing portion of the steel material 5a) and mounting the sleeve member 7c on the column 7a, the vertical displacement of the frame 5 relative to the column 7a is allowed without any problem. However, the relative displacement in the horizontal direction of the frame 5 is reliably restrained by the support column 7a, which can reliably prevent unnecessary horizontal force from acting on the air spring 4 while operating the air spring 4 without hindrance. It has become.

  Based on the above configuration, according to the three-dimensional seismic isolation device of the present embodiment, the laminated rubber 3 as the horizontal seismic isolation mechanism and the air spring 4 as the vertical seismic isolation mechanism against both horizontal vibration and vertical vibration. Excellent seismic isolation effect is obtained, and it is effective as a three-dimensional seismic isolation device that supports seismic isolation of the entire large-scale building.

In particular, the three-dimensional seismic isolation device of this embodiment uses a plurality of air springs 4 as a vertical seismic isolation mechanism, and combines the plurality of air springs 4 with a single laminated rubber 3 as a horizontal seismic isolation mechanism. Therefore, even if the supporting force of the individual air springs 4 is not sufficient, a sufficient supporting force can be secured by the whole of the plurality of air springs 4 and the supporting load can be increased by increasing or decreasing the number of the air springs 4. Can be set freely and widely, so that the support force of the entire air spring 4 can be appropriately balanced with the support force of the single laminated rubber 3.
As a result, it is possible to easily eliminate the imbalance between the support force of the laminated rubber and the air spring, which has been a problem in this type of general three-dimensional seismic isolation device. Therefore, it is sufficient to use small general-purpose products as the individual air springs 4, and to ensure the desired support capacity for the entire three-dimensional seismic isolation device without any significant cost increase. Is possible.

  Although one embodiment of the present invention has been described above, the above embodiment is merely a preferred example, and the present invention is not limited to the above embodiment, and various design examples such as those listed below are included. Variations and applications are possible.

The above embodiment is an example in which four air springs 4 are used, but the number of air springs 4 is naturally arbitrary, and the supporting force required for the entire three-dimensional seismic isolation device and the individual used. An appropriate number may be set based on the support force of the air spring 4. However, in any case, it is not preferable that an eccentric moment is generated in the entire three-dimensional seismic isolation device. Therefore, the arrangement of the air springs 4 is as much as possible around the center of the frame 5 so as to be point-symmetric. It should be arranged evenly and so that the position of the center of gravity as a whole matches the position of the center of gravity of the laminated rubber 3 as much as possible.
Of course, the specific configuration, shape, and dimensions of the frame 5 correspond not only to the rigidity required for the frame 5, but also to the dimensions of the laminated rubber 3 and the air spring 4, especially the number and arrangement of the air springs 4. And design as appropriate.

In the above embodiment, the bellows type by the rubber bellows 4a is used as the air spring 4 as the vertical seismic isolation mechanism. However, the type of the air spring 4 is not particularly limited. For example, the rolling as shown in Patent Document 3 is used. Various types of air springs including a seal-type air spring can be arbitrarily employed.
The air spring 4 preferably has a vibration damping function by the auxiliary tank 4b and the orifice 4c as in the above embodiment, but the vertical vibration damping mechanism 6 is added in parallel with the air spring 3 as described above. In the case where it is assumed that a proper damping mechanism is separately provided between the building 1 and the foundation 2, it is not always necessary to use such an air spring.

Similarly, as the laminated rubber 3 as the horizontal seismic isolation mechanism, a rubber having its own damping function such as one incorporating a lead plug or one using a high damping rubber can be suitably employed. This is not necessary when a separate damping mechanism is installed.
Further, as the horizontal seismic isolation mechanism, it is most common and practical to use the laminated rubber 3 as in the above embodiment, but when applied to a lightweight building or the like, it is more simplified instead of the laminated rubber 3. Adopting a sliding bearing or an elastic sliding bearing as a horizontal seismic isolation mechanism is not an obstacle. In any case, it is preferable to balance as much as possible the supporting force of the horizontal seismic isolation mechanism and the supporting force of the entire vertical seismic isolation mechanism by a plurality of air springs.

  Although it is preferable to install the horizontal deformation restraining mechanism 7 for restraining the horizontal deformation of the air spring 4 as in the above embodiment, the specific configuration thereof is arbitrary, and the horizontal displacement of the building 1 is other means. May be omitted in the case of being restrained by itself.

In the above embodiment, the laminated rubber 3 is disposed on the upper portion of the frame 5 and the plurality of air springs 4 are disposed on the lower portion. However, even if the top and bottom are reversed, they behave similarly and function similarly. That is, a plurality of air springs 4 may be disposed on the upper portion of the frame 5 and a single laminated rubber 3 (or a sliding bearing or an elastic sliding bearing) may be disposed on the lower portion. In this case, when the vertical vibration damping mechanism 6 and the horizontal deformation restraining mechanism 7 as in the above embodiment are provided, they are naturally installed between the frame 5 and the building 1 in parallel with the air spring 4. In that case, in either case, the top and bottom are reversed and their one end (in this case, the lower end) is connected to or engaged with the frame 5 and the other end (the same upper end) is connected to the building 1. And fix it.
Furthermore, the three-dimensional seismic isolation device of the present invention is not only installed between the foundation 2 and the building 1 as a basic isolation as in the above embodiment, but also installed on the intermediate floor of the building 1 as an intermediate isolation. Is also possible.

It is the top view and side view which show the three-dimensional seismic isolation apparatus which is embodiment of this invention. It is a figure which shows a horizontal deformation | transformation restraint mechanism similarly.

Explanation of symbols

1 building (superstructure)
2 Foundation (substructure)
3 Laminated rubber (horizontal seismic isolation mechanism)
4 Air spring (vertical seismic isolation mechanism)
4a Rubber bellows 4b Auxiliary tank 4c Orifice 5 Frame 5a Steel material 5b Reinforced steel plate 6 Vertical vibration damping mechanism 7 Horizontal deformation restraint mechanism 7a Post 7b Base member 7c Sleeve member 7d Bearing

Claims (4)

A horizontal seismic isolation mechanism and a vertical seismic isolation mechanism are arranged in series in the vertical direction, and are interposed between the building as the upper structure and the lower structure that supports it. A three-dimensional seismic isolation device configured to obtain a seismic effect,
A highly rigid frame is arranged between the horizontal seismic isolation mechanism and the vertical seismic isolation mechanism, and the horizontal seismic isolation mechanism and the vertical seismic isolation mechanism are integrated through the frame,
The horizontal seismic isolation mechanism consists of a single laminated rubber, a sliding bearing or an elastic sliding bearing fixed at the center position of the frame,
The three-dimensional seismic isolation device characterized in that the vertical seismic isolation mechanism is composed of a plurality of air springs arranged uniformly around the center position of the frame. The three-dimensional seismic isolation device according to claim 1,
The air spring as a vertical seismic isolation mechanism has an air chamber and an auxiliary tank attached to the air chamber, and the air chamber and the auxiliary tank communicate with each other through an orifice. 3D seismic isolation device. The three-dimensional seismic isolation device according to claim 1 or 2,
A vertical vibration damping mechanism for attenuating vertical vibrations of an air spring as a vertical seismic isolation mechanism is provided in parallel with the air spring, and one end of the vertical vibration damping mechanism is connected to a frame. Dimensional seismic isolation device. The three-dimensional seismic isolation device according to any one of claims 1 to 3,
A horizontal deformation restraining mechanism that restrains horizontal deformation while allowing vertical vibration of the air spring as a vertical seismic isolation mechanism is provided in parallel with the air spring, and one end of the horizontal deformation mechanism is perpendicular to the frame. A three-dimensional seismic isolation device that is engaged in such a manner that it can be displaced in the direction and cannot be displaced in the horizontal direction.

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