JP2005240929A - Seismic isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable seismic isolator which can tolerate large horizontal displacement and endure large pulling-out force, and also which is reduced in cost and the maintenance of which is easy. <P>SOLUTION: The seismic isolator 10 is arranged to connect a structure 1 and a base member 2 to each other. The seismic isolator includes a disk spring 11 which receives the pulling-out force N so as to be compressed when an earthquake occurs, and a wire 12 for transmitting the pulling-out force to the base member 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a seismic isolation device that reduces the input of seismic motion to the structure from the ground, and more particularly to a seismic isolation device suitable for use in structures such as high-rise buildings and tower-like structures.

Seismic isolation devices are known that reduce the earthquake motion transmitted from the ground to the structure during an earthquake. Laminated rubber, which has been widely used as a seismic isolation device for building structures and the like, can bear a heavy load against compression but cannot bear a pulling force (tensile force), so its application is 60m in height. The structure was limited to a degree.
However, in recent years, high-rise structures having a height exceeding 60 m are increasing. For this reason, recently, a seismic isolation mechanism that combines a rail bearing capable of bearing a tensile force and laminated rubber has been developed. For example, a seismic isolation structure is also applied to high-rise buildings such as apartment buildings with a height of 100m. It has become so. (For example, see Patent Document 1)
Japanese Patent Laid-Open No. 10-88849

By the way, when a seismic isolation device combining a rail support and laminated rubber is applied to a 100 m class high-rise building, it becomes necessary to withstand a pulling force (for example, approximately several hundred tons per side) during an earthquake. Moreover, at the time of an earthquake, it is necessary to adapt to relative horizontal displacement (for example, about 50 cm) simultaneously with the above-described pulling force.
However, the rail support part that bears the pulling force is configured such that the upper rail and the lower rail are jointed by a connecting metal, and the sliding surface of the connecting metal is formed by a bearing or the like to move with a small sliding (friction) resistance. It is a machine component that realizes For this reason, the conventional seismic isolation device that can cope with the pulling force is expensive and has a drawback of requiring regular maintenance.

In particular, for seismic isolation of large building structures and the like, a large load is always applied to the bearing part, so in order to prevent grease from running out at the contact point of the bearing part, for example, periodically with a large stroke. Large maintenance such as moving is required.
Moreover, since the vertical rigidity differs between the rail support and the laminated rubber, it is necessary to consider the load sharing in consideration of this. However, since the laminated rubber has a creep phenomenon, its design accuracy has a problem in terms of reliability.

In this way, in large buildings such as high-rise buildings where a large pulling force acts during an earthquake, a large horizontal sliding displacement is allowed and a large pulling force can be tolerated. Development of high seismic isolation devices is required.
The present invention has been made in view of the above circumstances, and the object of the present invention is to permit a large slide horizontal displacement and to withstand a large pulling force, and at a low cost and easy to maintain. The object is to provide a highly reliable seismic isolation device.

In order to solve the above problems, the present invention employs the following means.
The seismic isolation device according to the present invention is arranged so as to connect between the structure and the foundation member, and in the seismic isolation device that receives a pulling force during an earthquake, an elastic member that is compressed by receiving the pulling force; And a connecting member for transmitting the pulling force to the elastic member.

According to such a seismic isolation device, the elastic member that is compressed by receiving the pulling force and the connecting member that transmits the pulling force to the elastic member are configured. By compressing the elastic member received from the connecting member, it is possible to bear a pulling force corresponding to the compression amount of the elastic member while absorbing a relative horizontal displacement.
In this case, as a suitable connecting member for connecting the building structure side and the foundation member, there is a wire having a large tensile rigidity but a small bending rigidity. It is preferable that the contact surface is a curved surface and the wire is deformed along a large radius of curvature.

In the above-described seismic isolation device, it is preferable that the elastic member has a plurality of different spring constants arranged in series in the pulling direction, and thereby has a high spring constant that absorbs deformation while bearing a heavy load ( (High rigidity) The elastic member and the low spring constant (low rigidity) elastic member that deforms with a small load are combined. Therefore, after the elastic member with the low spring constant is first elastically deformed and reaches a predetermined position. An elastic member having a high spring constant is elastically deformed, and it is possible to cope with a pulling force while absorbing a large slide horizontal displacement during an earthquake.
When the seismic force is small and the slide horizontal displacement is small, generally no pulling force is generated, and when a large seismic force acts and the slide horizontal displacement becomes large, a pulling force is generated. In other words, while the slide horizontal displacement is small, the low-rigid elastic member is deformed and can be easily slid to maintain seismic isolation performance, and when the slide horizontal displacement is large and pulling force is generated, the high-rigid elastic member is deformed. Thus, it becomes possible to handle the pulling force.

  In the above seismic isolation device, it is preferable that the connecting position on the structure side is offset in the direction of the center position of the structure with respect to the connecting position on the base member side. It is possible to keep the compression force applied to the elastic body small during horizontal sliding.

  In the above seismic isolation device, it is preferable to combine with a laminated rubber bearing, and this can compensate for the disadvantage of laminated rubber that is weak against tensile force.

  In the above seismic isolation device, instead of the laminated rubber, it may be combined with an endless roller support orthogonal to the back to back. Thereby, an inexpensive slide bearing capable of supporting a large load can be applied.

According to the above-described seismic isolation device of the present invention, the elastic member receiving the pulling force during the earthquake from the connecting member is compressed, so that the pulling force corresponding to the compression amount of the elastic member is absorbed while absorbing the horizontal slide displacement. It bears the load and withstands the pulling force while allowing a large horizontal displacement of the seismic isolation layer. Therefore, by combining with low-cost seismic isolation bearings (laminated rubber bearings, endless roller bearings, etc.) that cannot bear the pulling force, it is possible to provide an inexpensive seismic isolation device that is also effective for seismic isolation of high-rise buildings. .
In addition, since a large installation space is not required unlike a rail support, the degree of freedom in design is increased and the adoption is facilitated. Further, since the elastic spring has a simple structure in which no tensile force acts, it is reliable for the design. It has the advantage of high performance.
Moreover, since it is a structure which can be removed, it also has the advantage that a maintenance becomes easy.

Hereinafter, an embodiment of a seismic isolation device according to the present invention will be described with reference to the drawings.
A seismic isolation device 10 shown in FIG. 1 is disposed in a seismic isolation layer provided between a structure 1 such as a high-rise house and a base member 2 that supports the structure 1, and connects both of them to the structure 1 during an earthquake. It is configured to receive a pulling force N. The seismic isolation device 10 employs a disc spring 11 as an elastic member that is compressed by receiving a force in the direction of the pulling force (upward in the vertical direction), and further, the disc spring 11 is compressed to form a structure for the base member 2. A wire 12 having a diameter d is employed as a connecting member that transmits a pulling force N corresponding to the amount of compression to the base member while absorbing the relative horizontal displacement of the object 1.

The upper end portion side of the wire 12 is fixedly supported on the lower end portion of the structure 1 via a wire connecting member 13. The wire connecting member 13 is configured to be firmly integrated so as to be embedded in the lower end portion of the structure 1.
In the wire connecting member 13, the upper end portion 12 a of the wire 12 is fixed by a well-known method. Further, at the connecting portion of the wire 12, a guide member 14 protrudes downward from the lower end surface of the wire connecting member 13. The guide member 14 is provided with a through hole 14a through which the wire 12 passes, and an inner peripheral surface of the through hole 14a serving as a wire contact surface is a curved surface with a radius of curvature set to R.

The lower end 12b of the wire 12 is fixedly supported by a guide shaft 15 of a disc spring 11 described later. In this case, the lower end portion 12b of the wire 12 is fixed to the upper flange portion 15a of the guide shaft 15 by the same method as the upper end portion 12a described above. A guide member 14 having a through hole 14a formed in a curved surface having a curvature radius R is provided on the upper surface of the flange portion 15a.
The above-described wire 12 is usually configured with a plurality of wires arranged in a balanced manner in consideration of load resistance. In the embodiment shown in FIG. 2, six wires 12 are arranged at a 60 ° pitch on the same circumference. Has been.

On the other hand, the disc spring 11 is inserted between the bottom end 15b side of the cylindrical guide shaft 15 and arranged in a large number in the vertical direction, and is held between the nut member 16 and the top regulating member 17 screwed into the bottom end 15b. Has been. The guide member 15 is housed in the recess 3 provided in the base member 2, and the upper end regulating member 17 is firmly fixed to the base member 2 so as to close the upper opening.
The guide shaft 15 passing through the through hole 17a of the upper restricting member 17 is supported in such a manner that the upper flange portion 15a is suspended by the wire 12, or the upper flange 15a is placed on the upper surface of the upper restricting member 17. It is assumed that it was done. For this reason, a large load is not always applied, and therefore, the maintenance is easy because it can be removed and the problem of running out of grease does not occur.

  The guide member 14 and the upper flange 15a described above are housed in a cylindrical upper outer cylinder 18. Similarly, the guide shaft 15, the disc spring 11, and the nut member 16 are accommodated in a cylindrical lower outer cylinder 19. In the illustrated configuration example, the upper outer cylinder 18 and the lower outer cylinder 19 are both supported by the upper end restricting member 17. A guide ring 20 is provided on the inner peripheral surface on the lower end side of the lower outer cylinder 19 so as to smoothly move the nut member 16 up and down by restricting horizontal movement of the nut member 16.

The seismic isolation device 10 having the above-described configuration operates as described below when an input due to an earthquake acts, and bears a pulling force generated during the seismic isolation.
The horizontal relative movement W generated between the structure 1 and the base member 2 due to the earthquake is permitted by compressive deformation of the disc spring 11 and the inclination of the wire 12. At this time, since both ends of the wire 12 pass through the through-hole 14a formed in the curved surface having the curvature radius R, when the wire 12 is inclined as indicated by an imaginary line in the drawing due to the relative movement W, the wire 12 gradually Since the wire 12 is inclined while being drawn, the stress concentration is less likely to occur in the wire 12.
According to the applicant's many years of experience regarding the relationship between the crane sheave diameter and the wire diameter, the ratio (R / d) of the curvature radius R of the curved surface to the diameter d of the wire 12 is about 12.5. If it is set, it has been found that the wire 12 is not cut by stress concentration.

  Further, when the structure 1 is greatly slid in the horizontal direction due to the seismic force, the overturning moment generated in the structure is increased and a pulling force more than the compressive force due to its own weight acts, the guide shaft 15 is moved to the upper flange portion 15a and the nut member 16. At the same time, the disk spring 11 is largely pulled up and the disk springs 11 arranged between the upper end regulating member 17 and the nut 16 are greatly compressed. As a result, the pull-out force of the earthquake input balances with the spring force corresponding to the compression deformation of the disc spring 11, so that a large pull-out force can be accommodated while allowing a large relative movement W in the horizontal direction.

Next, a second embodiment of the seismic isolation device shown in FIG. 3 will be described. In addition, the same code | symbol is attached | subjected to the member similar to 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted.
The seismic isolation device 10 </ b> A of this embodiment includes a coil spring 21 arranged in series with the disc spring 11. The coil spring 21 is a soft elastic member (low-rigidity spring) having a spring constant set smaller than that of the disc spring 11 and is inserted below the guide shaft 15 </ b> A and disposed below the disc spring 11. That is, the seismic isolation device 10A of this embodiment has a configuration in which two types of elastic members (between the spring 11 and the coil spring 21) having different spring constants are arranged in series in the drawing direction.
In the figure, reference numeral 22 denotes a disc spring holding member that is loosely inserted into the guide shaft 15A and freely slides, and 23 is a coil spring holding member integrated with the guide shaft 15A by screwing or the like.

  In the seismic isolation device 10A having the above-described configuration, when a pulling force acts due to an earthquake, the coil spring holding member 23 is first pulled up together with the guide shaft 15A, so that the coil spring 21 having a small spring constant becomes the disc spring holding member 22 and the coil. It is sandwiched between the spring holding member 23 and receives pressure. When the coil spring 21 compressed by this pressing is elastically deformed to a predetermined position, the disc spring holding member 22 is now also lifted up in the same manner as in the first embodiment described above, so that the disc with a large spring constant is obtained. The spring 11 is similarly compressed.

  With such a configuration, the elastic bodies having different spring constants are arranged in series, so that the two-stage compression deformation occurs, and accordingly, the horizontal slide displacement is absorbed even by the elastic deformation of the coil spring 21. Will be able to. For this reason, when the seismic force is small and the slide displacement is small, the coil spring 21 is deformed and can be easily slid to maintain seismic isolation performance. When the slide displacement becomes large and pulling force is generated, the disc spring is deformed. Thus, it becomes possible to cope with the pulling force, and the pulling force can be effectively transmitted to the base member without impairing the seismic isolation performance.

Then, 3rd Embodiment of the seismic isolation apparatus by this invention is described based on FIG. In addition, the same code | symbol is attached | subjected to the part similar to embodiment mentioned above, and the detailed description is abbreviate | omitted.
The seismic isolation device 10B of this embodiment is different in that the universal shaft 30 is interposed at both ends of the guide shaft 15B connected to the structure 1 and the base member 2 to absorb horizontal slide displacement. Yes. In the illustrated example, the disc springs 11 and the coil springs 21 having different spring constants are arranged in series. However, as shown in FIG. 1, only the disc springs 11 may be provided.

By adopting such a universal joint 30, when a horizontal slide displacement acts, the spring is compressed and deformed, and the guide shaft 15B is inclined with the universal joint 30 as a fulcrum. The drawing force can be borne while absorbing the displacement.
In such a configuration, the universal joint 30 and the guide shaft 15B serve as a connecting member that transmits the pulling force to the base member.

Moreover, in each embodiment mentioned above, although the guide shaft 15 connected with the structure 1 and the foundation member 2 was located on the vertical line in the normal state without an earthquake, for example, as shown in FIG. The connection position S1 on the structure 1 side may be offset from the connection position S on the side by the length a in the structure center position direction (left direction on the paper surface).
With such a configuration, it is possible to suppress a compressive force generated in an elastic member such as a disc spring at the time of horizontal sliding to the side where the pulling force does not act, thereby facilitating horizontal sliding and suppressing a decrease in seismic isolation performance.

Further, as shown in FIG. 6, in addition to the offset described above, an intermediate hinge portion H may be provided on the guide shaft 15 ′ that connects the connecting position S on the base member 1 side and the connecting position S1 on the structure 2 side. Good.
Even in such a configuration, as described above, it is possible to facilitate the horizontal slide to the side where the pulling force does not act, and to suppress the seismic isolation performance deterioration.

Moreover, it is preferable to use the seismic isolation apparatus of each embodiment mentioned above in combination with the laminated rubber bearing which cannot respond to drawing force.
FIG. 7 shows a configuration example in which the seismic isolation device 10 shown in the first embodiment and the laminated rubber bearing 40 are combined. The laminated rubber bearing 40 supports the structure and supports the structure during an earthquake. Slide horizontally to make the natural period longer, and change to slow shaking to reduce seismic force. However, if a pulling force is applied by the overturning moment generated in the structure, this cannot be borne. The seismic isolation device 10 corresponds to this pull-out force, and can provide an inexpensive seismic isolation device that compensates for the disadvantage of the laminated rubber bearing 40, which is weak against tensile force.

Further, the seismic isolation device of the present invention may be combined with an endless roller bearing orthogonal to the back to back instead of the laminated rubber bearing 40 described above.
FIG. 8 is a perspective view showing a configuration example of the endless roller support. The endless roller support 50 has four downward endless rollers 52 arranged so as to be movable in the same direction (X-axis direction) with the surface from which the roller 51 is exposed downward, and the surface from which the roller 51 is exposed upward. It comprises four upward endless rollers 53 arranged so as to be movable in the same direction (Y-axis direction).

The endless roller bearing 50 having such a configuration is disposed between the structure 1 and the base member 2 together with the above-described seismic isolation device 10, so that the endless roller bearing 50 can convert the horizontal component due to the earthquake to the X axis. And it absorbs by moving in the Y-axis direction. Further, the weight of the structure is supported by the endless roller support 50, and the pull-out force due to the overturning moment generated in the structure during an earthquake can be handled by the seismic isolation device 10.
Thus, the seismic isolation device of the present invention described above eliminates the need for a rail bearing that is expensive and requires regular maintenance by adopting a configuration in combination with the laminated rubber bearing 40 and the endless roller bearing 50.
In addition to the laminated rubber bearing and the endless roller bearing, a structure such as a friction bearing or a sliding bearing that can not bear the pulling force may be combined.

Moreover, when installing the seismic isolation apparatus of this invention mentioned above, since the space of a horizontal direction is not especially required like a rail support, it has the advantage that the freedom degree which designs the structure 1 increases.
Moreover, since the above-described seismic isolation device of the present invention has a configuration in which a tensile force does not act on the elastic body, there is an advantage that it becomes a highly reliable device.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary of this invention, it can change suitably.

It is sectional drawing which shows 1st Embodiment of the seismic isolation apparatus which concerns on this invention. It is AA sectional drawing of FIG.1 and FIG.3. It is sectional drawing which shows 2nd Embodiment of the seismic isolation apparatus which concerns on this invention. It is sectional drawing which shows 3rd Embodiment of the seismic isolation apparatus which concerns on this invention. It is a figure which shows the 1st modification of the seismic isolation apparatus which concerns on this invention. It is a figure which shows the 2nd modification of the seismic isolation apparatus which concerns on this invention. It is a figure which shows the state which used the seismic isolation apparatus of this invention in combination with the laminated rubber bearing. It is a perspective view which shows the structural example of an endless roller support.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Structure 2 Base member 3 Recess 10, 10, A, 10B Seismic isolation device 11 Disc spring (elastic member)
12 wire (connection member)
13 Wire connecting member 14 Guide member 15, 15A, 15 ', 15B Guide shaft 16 Nut member 17 Upper end regulating member 21 Coil spring 30 Universal joint 40 Laminated rubber bearing 50 Endless roller bearing

Claims (5)

In the seismic isolation device that is arranged so as to connect the structure and the foundation member and receives the pulling force in the event of an earthquake,
An elastic member that is compressed by receiving the pulling force;
A connecting member for transmitting the pulling force to the elastic member;
A seismic isolation device characterized by comprising:   The seismic isolation device according to claim 1, wherein the elastic member includes a plurality of types having different spring constants arranged in series in the drawing direction.   The seismic isolation device according to claim 1 or 2, wherein the connection position on the structure side is offset in the direction of the center position of the structure with respect to the connection position on the foundation member side.   4. The seismic isolation device according to claim 1, wherein the seismic isolation device is combined with a laminated rubber bearing.   The seismic isolation device according to any one of claims 1 to 3, wherein the seismic isolation device is combined with an endless roller support body orthogonal to the back to back.

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