JP4240649B2 - Multi-slip composite seismic isolation unit and seismic isolation structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multistage sliding composite seismic isolation unit in which a seismic isolation device using a laminated rubber bearing and a seismic isolation device using a sliding bearing are unitized in multiple stages, and a seismic isolation structure in which the unit is arranged.
[0002]
[Prior art]
In recent years, in order to ensure the safety of a structure against earthquakes, let's propagate it from the ground to the structure by an earthquake etc. by installing seismic isolation devices on the foundation part of the structure or pillars on the intermediate floor. Various seismic isolation structures have been developed that reduce the stress and deformation generated in the structural frame by attenuating the vibration.
Conventionally, as a seismic isolation device used for such a seismic isolation structure, an elastic bearing system using a laminated rubber or the like and a sliding bearing system or a rolling bearing system are known.
[0003]
Here, seismic isolation devices using elastic bearings using laminated rubber are bearing members that have a large load-bearing capacity and horizontal displacement capacity by laminating thin steel sheets and rubber sheets alternately in multiple layers. The relative displacement in the horizontal direction that is sometimes generated is absorbed by highly elastic rubber, and the natural period of the structure is lengthened, thereby reducing the influence of seismic force.
[0004]
The sliding support system seismic isolation device is fixed to the lower surface of the upper structure and a flat sliding plate mounted on the lower structure such as a foundation, and is slidably provided on the sliding plate. In addition, it supports the vertical load from the upper structure in normal times, and when the lower structure is displaced horizontally during an earthquake, the sliding material By sliding on the sliding plate, the horizontal seismic force that acts on the superstructure is attenuated by the frictional force generated at the time of sliding, and the soundness of the superstructure is ensured.
[0005]
[Problems to be solved by the invention]
By the way, although the seismic isolation device based on the elastic support can extend the natural period of the structure due to its elasticity, it cannot expect a high damping effect on the seismic force.
On the other hand, the seismic isolation device by the sliding bearing has the advantage that the effect of damping the seismic force is obtained by the frictional force when the sliding material slides on the sliding plate, and there is no possibility of buckling at the time of large deformation, Since it does not have a function of returning the structure to the vicinity of the original position after the earthquake, it is necessary to separately install a restoring device such as a spring.
[0006]
Therefore, conventionally, when a structure is to be seismically isolated using such a seismic isolation device, a construction method using a combination of the above-described multiple types of seismic isolation devices has been adopted. In particular, when a seismic isolation device with a laminated rubber bearing and a seismic isolation device with a sliding bearing are combined, an appropriate friction coefficient and restoring force can be obtained, and the natural period can be increased. And an effective seismic isolation structure can be realized.
[0007]
However, when the seismic isolation device for laminated rubber bearings and the seismic isolation device for sliding bearings are combined in this way, the seismic isolation device for sliding bearings or laminated rubber bearings is individually applied to each foundation or column. Because of the interposition, there is a risk that the structure will sink unsettled due to the difference in the amount of settlement due to the difference in vertical rigidity. This necessitates a problem that design constraints become large.
[0008]
In addition, from the viewpoint of extending the natural period described above, it is advantageous to increase the height of the seismic isolation device by elastic bearings. When a large relative displacement occurs in the meantime, there is a risk that the structure will collapse due to excessive deformation and collapse of the structure.
In addition, in the above conventional seismic isolation structure, since the seismic isolation devices for individually manufactured sliding bearings or laminated rubber bearings are installed for each column or foundation, the number of components increases. There is a problem that the construction is complicated, the installation work requires a lot of time and labor, and the cost is increased.
[0009]
The present invention has been made in view of such circumstances, and there is no risk of causing inhomogeneous settlement of the structure or buckling of the seismic isolation device by the elastic bearing, and the structure has a long period of time and high height. It is intended to provide a multi-stage sliding composite seismic isolation unit that can exhibit excellent seismic isolation performance due to attenuation, is easy to construct and is economical, and a seismic isolation structure using the same. is there.
[0010]
[Means for Solving the Problems]
  A multi-stage sliding composite seismic isolation unit according to the present invention described in claim 1 includes a pair of fixing plates each fixed to an upper structure and a lower structure, and two or more connecting plates disposed between the fixing plates, These connecting platesBetween each other and between the connecting plate and the fixing plate.A first seismic isolation device with a sliding bearing;Provided between the connecting plates and between the connecting plate and the fixing plateWith a second seismic isolation device with elastic bearingsThe first seismic isolation device is slidably provided on the fixing plate or the coupling plate facing the sliding member at the tip, by fixing each main body to the coupling plate.It is characterized by. Here, in the first seismic isolation device, the main body portion other than the surface sliding with the fixing plate is formed by a rigid body such as steel (rigid sliding support) and an elastic body such as laminated rubber. (Including elastic sliding bearings). On the other hand, as the second seismic isolation device, for example, a seismic isolation device using laminated rubber is suitable.
[0011]
  Further, according to claim 2Seismic isolation structureIsThe multistage sliding composite seismic isolation unit according to claim 1 is disposed between the axial force members to be interposed with the upper and lower structure seismic isolation devices.It is characterized by this.
[0012]
  In additionThe second seismic isolation device is preferably disposed around the first seismic isolation device so as to surround it, and a plurality of second seismic isolation devices are disposed around the first seismic isolation device. Alternatively, it is preferable that the second seismic isolation device is formed in an annular shape, and the first seismic isolation device is arranged at the center of the second seismic isolation device.
[0015]
  The multistage sliding composite seismic isolation unit according to claim 1 and the sameClaim 2According to the seismic isolation structure described in No. 1, any of the first seismic isolation devices using the sliding bearings arranged in multiple stages does not slip during a small earthquake or a strong wind. Therefore, when the first seismic isolation device is a rigid sliding bearing, a stable state is maintained without causing a relative displacement between the upper and lower fixing plates of the unit. On the other hand, when the first seismic isolation device is an elastic sliding bearing, the first and second seismic isolation devices exhibit a seismic isolation effect due to small shear deformation.
[0016]
Next, when a medium-scale earthquake occurs, among the plurality of first seismic isolation devices arranged vertically between the fixing plate and the connecting plate, the fixing plate facing the one with the smallest frictional resistance or Slide against the connecting plate. Along with this, the second seismic isolation device adjacent to the first seismic isolation device is elastically deformed to follow this. Then, the seismic energy is caused by the frictional energy generated between the first seismic isolation device and the fixing plate that caused the slip and the damping effect due to the elastic deformation of the second seismic isolation device adjacent thereto. Absorbed.
[0017]
Furthermore, when a large earthquake occurs, all the first seismic isolation devices located above and below slide relative to the opposing fixing plate or connecting plate, respectively. As a result, all the second seismic isolation devices positioned above and below are also elastically deformed, so that the structure has a longer period, the transmission of vibration to the upper structure is reduced, and the first seismic isolation device is also achieved. The vibration energy is absorbed by the frictional energy generated between the seismic device and the fixing plate or connecting plate, and the seismic force is attenuated. Furthermore, after the earthquake, the structure is pulled back to the vicinity of the original position by the elastic force of the second seismic isolation device.
[0018]
In this way, according to the multi-slip composite seismic isolation unit, the single unit can achieve both long-period and high-attenuation performance, and thus a wide range of seismic forces from small earthquakes to large earthquakes. In contrast, a high seismic isolation effect is demonstrated.
In addition, even when a large earthquake occurs and the upper and lower structures are relatively displaced in the horizontal direction, the second seismic isolation devices with elastic bearings are arranged in multiple stages in the vertical direction. The amount of deformation in the seismic isolation device 2 is reduced, so there is no risk of buckling.
[0019]
At this time, the vertical load acting on the axial force members such as the pillars and foundations of the structure during normal operation is the same as that of the first seismic isolation device by the sliding support in the multistage sliding composite seismic isolation unit installed in the lower part. It is jointly borne by the second seismic isolation device with an elastic bearing. Here, the ratio of the burden in the first and second seismic isolation devices is determined by the ratio of the vertical rigidity of both seismic isolation devices.
[0020]
On the other hand, when an earthquake occurs and the first seismic isolation device slips, the greater the relative displacement of the upper and lower fixing plates, the lower the vertical stiffness in the elastically deformed second seismic isolation device, As a result, the ratio of the burden of the vertical load in the first seismic isolation device increases. And when the second seismic isolation device is greatly deformed during a large earthquake, the second seismic isolation device can no longer support the vertical load, and conversely, it is pulled on the upper and lower fixing plates to which it is fixed. Power will act. Even in such a case, since the vertical load can be supported by the first seismic isolation device, the stability of the entire unit can be maintained, and thus the upper structure does not become unstable.
[0021]
Furthermore, in this multi-stage sliding composite seismic isolation unit, if the friction coefficient in the first seismic isolation device by sliding bearing is μ and the load factor of the vertical load is β, the effective friction coefficient μe as a unit is μe = μ · β. In normal times and small earthquakes, the second seismic isolation device also bears a certain vertical load. As a result, β <1.0, so μe <μ. Slip can be produced in the device from small accelerations.
[0022]
In addition, when an earthquake occurs, the load factor β of the vertical load in the first seismic isolation device is such that the amount of shear deformation of the second seismic isolation device due to the elastic bearing increases, and the burden rate in the second seismic isolation device is As it gets smaller, it gets bigger. And as mentioned above, when a 2nd seismic isolation device deform | transforms greatly at the time of a big earthquake and a tensile force acts on both fixing plates, the 1st seismic isolation device bears the said tensile force. Therefore, β> 1.0, and thus μe> μ. As a result, as a large relative displacement occurs between the fixing plates, the frictional force in the first seismic isolation device increases, the braking action for suppressing the deformation of the unit increases, and the damping effect of the seismic force also increases. . Thus, according to the multistage sliding composite seismic isolation unit, by adjusting the cross-sectional area of the first seismic isolation device and the second seismic isolation device, the vertical load burden ratio β is arbitrarily set. , Μe can be freely controlled, and thus a unit having an optimum performance corresponding to the characteristics of the structure can be easily realized.
[0023]
In addition, since the pair of fixing plates and connecting plates, and the first seismic isolation device by the sliding bearing and the second seismic isolation device by the elastic bearing are unitized, if the unit is manufactured in advance in a factory, etc. In addition, it is only necessary to install this unit between predetermined axial force members at the site, so that transportation and installation work can be facilitated and the construction period can be shortened, and the construction cost can also be reduced. become.
[0024]
Further, in the multi-stage sliding composite seismic isolation unit according to the present invention, since the first seismic isolation device having three or more stages is incorporated vertically, the slip displacement amount in the first seismic isolation device of each stage is one step. Compared to the case of, it is smaller to the value divided by the number of steps. For example, in the case of three stages, it becomes 1/3, and in the case of four stages, it becomes 1/4. As a result, the dimensions of the fixing plate and the connecting plate can be further reduced, and the entire unit can be reduced in size.
[0025]
Furthermore, if a large relative displacement occurs between the upper and lower structures during a major earthquake, a multi-slip composite seismic isolation unit generates a falling moment (rotational force). The substructure, the first seismic isolation device, the fixing plate and the connecting plate are sufficiently rigid, and the second seismic isolation device exerts an anti-rotation action against excessive tensile or compressive force. Therefore, the stability of the unit is not impaired.
[0027]
  On the other hand, as the second seismic isolation device, seismic isolation devices with various elastic bearings are applicable, but from the viewpoint of stably sharing and supporting the load of the superstructure together with the first seismic isolation device.,productIt is preferable to use a seismic isolation device using layer rubber. Also in this case, it is also preferable if the second seismic isolation devices adjacent to each other in the vertical direction are arranged so that at least some of them overlap each other in a plan view. It is more preferable that the lowermost second seismic isolation device is disposed so that at least a part thereof overlaps in plan view.
  In addition, a cover that closes the outer periphery of the fixing plate is provided.ByA dustproof effect between the fixing plates can be obtained, and the slidability by the first seismic isolation device can be ensured for a long period of time.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
1 to 3 show a first embodiment of a multistage sliding composite seismic isolation unit and a seismic isolation structure using the same according to the present invention.
As shown in FIG. 1 and FIG. 2, this seismic isolation structure has a multi-stage sliding composite isolation between a foundation (lower structure) 1 and a lower position of a pillar (axial material) of a building (upper structure) 2. The seismic unit 3 is installed.
Here, the multistage sliding composite seismic isolation unit 3 is configured by integrating two sets of the same type of composite seismic isolation units 4 and 4. Each of the composite seismic isolation units includes a pair of fixing plates 5a and 5b opposed to each other, a connecting plate 6 disposed between the fixing plates 5a and 5b, and the connecting plate 6 and the fixing plates 5a and 5b. The first seismic isolation device 7 using a sliding bearing provided between them, the second seismic isolation device 8 using laminated rubber, and a dustproof cover 9 provided between the outer peripheral portions of the fixing plates 5a and 5b. It is configured.
[0029]
The fixing plates 5a and 5b and the connecting plate 6 are square plates each having a predetermined rigidity made of a steel plate or the like, and the upper surface of the fixing plate 5a and the lower surface of the fixing plate 5b are each processed with a smooth surface. A sliding plate 10 made of a stainless steel plate or the like is integrally joined. The first seismic isolation device 7 is disposed in the center between the fixing plates 5 a and 5 b and the connecting plate 6.
[0030]
In the present embodiment, the first seismic isolation device 7 includes a cylindrical main body portion 7a formed of a rigid body such as a steel material, and a Teflon or the like that is integrally attached to the distal end portion of the main body portion 7a. It consists of the sliding material 7b which becomes (rigid sliding bearing). These first seismic isolation devices 7 are arranged so that the axes of the main body portions 7a coincide with each other, the main body portions 7a are attached to the connecting plate 6 by bolts, and the sliding material 7b is a sliding plate on the fixing plates 5a and 5b. 10 is slidable relative to 10.
[0031]
The second seismic isolation device 8 is constructed by alternately stacking steel plates and rubber sheets having a predetermined thickness in multiple layers. The second seismic isolation device 8 is formed at the four corners of the fixing plates 5a and 5b as a whole. 1 seismic isolation devices 7 are arranged so that their axes are aligned in the vertical direction. And these 2nd seismic isolation devices 8 are attached between the fixing plate 5a, 5b and the connecting plate 6 by attaching both end flanges to the connecting plate 6 and the fixing plate 5a or the fixing plate 5b with bolts. It is attached.
Further, in each composite seismic isolation unit 4, the fixing plates 5a and 5b are flexible between the outer peripheral edges of the fixing plates 5a and 5b and capable of following the relative displacement of the fixing plates 5a and 5b. The dustproof cover 9 made of a material is provided.
[0032]
  The multi-slip composite seismic isolation unit 3 includes the two sets of composite seismic isolation units 4 between the fixing plates 5a and 5b (which function as one connecting plate in the unit 3) located in the middle portion. The contact plate 12 is interposed and connected and integrated by a bolt 13.Further, the fixing plates 5a and 5b and the contact plate 12 located in the intermediate portion constitute a connecting plate.
  In the multi-slip composite seismic isolation unit 3 having the above configuration, the lower fixing plate 5 a is fixed to the upper surface of the foundation 1 via the anchor bolt 14, and the upper fixing plate 5 b is fixed to the building 2 via the anchor bolt 15. It is installed between the foundation 1 and the building 2 by being fixed on the lower surface.
[0033]
Next, based on FIGS. 1-3, it demonstrates about the effect | action of the multistage sliding composite seismic isolation unit 3 which consists of the above structure, and the seismic isolation structure which interposed this.
First, as shown in FIG. 1, when the horizontal force acting on the building 2 is small during normal times or during a small earthquake or strong wind, the sliding material of the first seismic isolation device 7 arranged in four stages. 7b does not cause the sliding plate 10 to slip, and the multistage sliding composite seismic isolation unit 3 is maintained in a stable state.
[0034]
Next, when a medium-scale earthquake occurs, the sliding material 7 b having the lowest frictional resistance among the first seismic isolation devices 7 slides on the sliding plate 10. Accordingly, the second seismic isolation device 8 adjacent to the first seismic isolation device 7 is elastically deformed to follow this. And, due to the frictional energy generated between the first seismic isolation device 7 causing the slip at this time and the sliding plate 10, and the damping effect due to the elastic deformation of the second seismic isolation device 8 adjacent thereto, The seismic energy is absorbed.
[0035]
Then, when a large earthquake occurs, as shown in FIG. 3, the sliding members 7b of all the first seismic isolation devices 7 positioned above and below the sliding plates 10 of the fixing plates 5a and 5b facing each other. It slides and all the second seismic isolation devices 8 are elastically deformed together. As a result, the period of the building 2 is increased, vibration transmission to the building 2 is reduced, and vibration energy is absorbed by the frictional energy generated between the sliding material 7b and the sliding plate 10, thereby causing an earthquake. The force is attenuated. Furthermore, after the earthquake, the building 2 is pulled back to the vicinity of the original position by the elastic force of the second seismic isolation device 8.
[0036]
Thus, according to the multi-slip composite seismic isolation unit 3 described above, both the long-period performance and the high attenuation performance can be realized by one unit, and thus a wide range of earthquakes ranging from small earthquakes to large earthquakes. High seismic isolation effect can be demonstrated for the force. In addition, even when a large earthquake occurs and a large relative displacement occurs between the foundation 1 and the building 2, the second seismic isolation devices 8 are arranged in four stages in the vertical direction. The amount of deformation in the second seismic isolation device 8 is reduced, so that there is no risk of buckling.
[0037]
At this time, in normal times, as shown in FIG. 1, the vertical load N acting on the multi-slip composite seismic isolation unit 3 from the building 2 is the same as that of the first seismic isolation device 7 arranged in four stages. The vertical load N acting through the first seismic isolation device 7 is jointly borne by the second seismic isolation device 8.₁Is N₁= N-4N₂become. Here, the ratio of the burden in the first seismic isolation device 7 and the second seismic isolation device 8 is determined by the ratio of the vertical rigidity of both seismic isolation devices.
Then, when a medium-scale earthquake occurs and only the sliding material 7b of some of the first seismic isolation devices 7 slips, and only the second seismic isolation device 8 adjacent thereto is elastically deformed, The vertical stiffness in the second seismic isolation device 8 is reduced, and the load burden N by the second seismic isolation device 8 is reduced.₂As a result, the vertical load N acting through the first seismic isolation device 7 is reduced.₁Will increase.
[0038]
Furthermore, as shown in FIG. 3, when all the second seismic isolation devices 8 are greatly deformed during a large earthquake, the second seismic isolation devices 8 cannot support a vertical load. Tensile force N is applied to the fixing plates 5a and 5b to which this is fixed.₂″ Will act, the vertical load N acting through the first seismic isolation device 7₁″ Is N₁″ = N + 4N₂Even in such a case, the vertical load N is reduced by the first seismic isolation device 7.₁”Can be supported, so that the stability of the multistage sliding composite seismic isolation unit 3 as a whole can be maintained.
As shown in FIG. 3, when a large relative displacement occurs between the foundation 1 and the building 2 during a large earthquake, the multi-slip composite seismic isolation unit 3 is accompanied by a tipping moment (rotational force). However, the foundation 1, the building 2, the first seismic isolation device 7, the fixing plates 5a and 5b located in the middle, and the connecting plate 6 are sufficiently rigid against the rotational force. Since the seismic isolation device 8 exhibits a rotation suppressing action against an excessive tensile force or compressive force, the stability of the unit 3 is not impaired.
[0039]
Further, in this multi-stage sliding composite seismic isolation unit 3, the friction coefficient in the first seismic isolation device 7 is μ, and the load factor of the vertical load is β (= N₁/ N), the effective friction coefficient μe as the multi-stage sliding composite seismic isolation unit 3 is μe = μ · β. In normal times and during small earthquakes, β <1.0, and therefore μe <μ. Therefore, the first seismic isolation device 7 can cause slipping from a small acceleration.
In addition, by changing the friction coefficient in the sliding material 7b of the four-stage first seismic isolation device 7, only some of the seismic isolation devices 7 can freely set the horizontal force. .
[0040]
When the earthquake occurs, the load factor β of the vertical load in the first seismic isolation device 7 is large, and the shear rate of the second seismic isolation device 8 is large, and the burden factor in the second seismic isolation device 8 is small. As it becomes, it grows. Then, as shown in FIG. 3, the upper and lower second seismic isolation devices 8 are greatly deformed in the event of a large earthquake, and a tensile force N is applied to the fixing plates 5a and 5b.₂″ Acts, the first seismic isolation device 7 has this tensile force N₂″ Is also burdened, so β> 1.0, and thus μe> μ. As a result, as the large relative displacement occurs between the fixing plates 5a, 5b, the first seismic isolation device 7 The frictional force increases, so that the brake action for suppressing the relative displacement of the fixing plates 5a and 5b increases, and the damping effect of the seismic force also increases.
[0041]
Thus, according to the multistage sliding composite seismic isolation unit 3 having the above-described configuration and the seismic isolation structure using the same, the plane cross-sectional areas of the first seismic isolation device 7 and the second seismic isolation device 8 are adjusted. Then, μe can be freely controlled by arbitrarily setting the vertical load sharing rate β or by appropriately setting the friction coefficient in the first seismic isolation device 7, and thus corresponds to the characteristics of the building 2. The multi-slip composite seismic isolation unit 3 having the optimum performance can be easily realized.
[0042]
Moreover, two pairs of composite seismic isolation units 4 comprising a pair of fixing plates 5a and 5b and a connecting plate 6, a first seismic isolation device 7 by a sliding bearing and a second seismic isolation device 8 by an elastic bearing are formed by bolts 13. By connecting and integrating, the entire multi-stage sliding composite seismic isolation unit 3 is unitized. Therefore, if the multi-stage sliding composite seismic isolation unit 3 is manufactured in advance in a factory or the like, the unit 3 is installed on the site at a predetermined level. It is only necessary to install it at the position, so that transportation and installation work are easy, and the construction period can be shortened and the construction cost can be reduced.
[0043]
Moreover, in the said multistage sliding composite seismic isolation unit 3, the 1st seismic isolation apparatus 7 by a four-stage sliding support is integrated up and down. Therefore, as shown in FIG. 4, in a general seismic isolation device using single-sided sliding, if the diameter of the seismic isolation device is φ, the required sliding plate dimension with respect to the one-side maximum slip amount δ is L = 2δ + φ. In addition, as shown in FIG. 5, in the case of double-sided sliding by a two-stage seismic isolation device, L ′ = δ + φ, whereas according to the unit 3, as shown in FIG. Since the required length L ″ of the sliding plate with respect to the quantity δ = δ / 2 + φ, it can be reduced to almost ¼ of that in the case of single-side sliding, so that the size reduction of the unit 3 can be achieved. Become.
[0044]
Furthermore, when a large earthquake occurs, the first seismic isolation device 7 that slides in the horizontal direction is disposed in the center between the fixing plates 5a and 5b and the connecting plate 6, and the second so as to surround it. Since the seismic isolation device 8 is provided, no extra area is required on the outer periphery of the fixing plates 5a and 5b, and the entire unit 3 can be further reduced in size.
In addition, since a dustproof cover 9 is provided between the outer peripheral portions of the fixing plates 5a and 5b, a dustproof effect between the fixing plates 5a and 5b and the connecting plate 6 can be obtained, and the first over a long period of time. The sliding property between the sliding member 7b of the seismic isolation device 7 and the sliding plate 10 can be ensured.
[0045]
(Embodiment 2)
FIG. 7 shows a second embodiment of the multi-slip composite seismic isolation unit of the present invention and a seismic isolation structure using the same, and the same components as those shown in FIGS. 1 and 2 are the same. The description will be simplified with reference numerals.
As shown in FIG. 7, the multi-slip composite seismic isolation unit 20 includes a composite seismic isolation unit 4 shown in FIG. 1 and a composite seismic isolation unit 21 arranged on the upper part of the unit 4. It is constituted by.
The composite seismic isolation unit 21 includes a pair of fixing plates 5a and 5b arranged opposite to each other, a first seismic isolation device 7 using a sliding support provided between the fixing plates 5a and 5b, and a second using a laminated rubber. And the dustproof cover 9 provided between the outer peripheral portions of the fixing plates 5a and 5b.
[0046]
  The multi-slip composite seismic isolation unit 20 includes an adhesive plate between the two pairs of composite seismic isolation units 4 and 21 (which function as one connecting plate in the unit 20) facing each other. 12 is interposed and connected and integrated by a bolt 13.Further, the fixing plates 5a and 5b and the contact plate 12 facing each other constitute a connecting plate.
  In the multi-slip composite seismic isolation unit 20 having the above-described configuration, the lower fixing plate 5a is fixed to the upper surface of the foundation 1 via the anchor bolts 14, and the other upper fixing plate 5b, as shown in FIG. Is fixed to the lower surface of the building 2 via the anchor bolts 15, and is installed between the foundation 1 and the building 2.
[0047]
Even in the multistage sliding composite seismic isolation unit 20 having the above-described configuration and the seismic isolation structure using the same, the same operational effects as those shown in the first embodiment can be obtained.
Incidentally, according to the multi-slip composite seismic isolation unit 20 described above, since the first seismic isolation device 7 is arranged in three upper and lower stages, the maximum displacement on one side of the entire unit 20 due to relative displacement between the foundation 1 and the building 2 is achieved. When the slip amount is δ, the corresponding required length of the sliding plate is 2δ / 3 + φ, and therefore can be reduced to almost １ ／ of the case of one-side slip.
[0048]
In the above embodiment, only the case where the composite seismic isolation unit 3 is interposed between the foundation 1 and the building 2 has been described, but the present invention is not limited to this. The same applies to the case of intervention.
In the above-described composite seismic isolation unit 3, the case where four sets of second seismic isolation devices 6 are arranged around the first seismic isolation device 7 has been described. May be arranged in an annular shape around the first seismic isolation device 7, or the second seismic isolation device may be formed in an annular shape and the first seismic isolation device 7 may be arranged in the center. Also good.
[0049]
Further, as the first seismic isolation device 7 only when a rigid sliding support device in which a sliding material 7b made of Teflon or the like is integrally provided at the distal end portion of the main body portion 7a formed of a rigid body is applied. Although it demonstrated, it is not restricted to this, Seismic isolation of the elastic sliding bearing which formed a part or all the main-body parts 7a with elastic bodies, such as laminated rubber, and integrated the same sliding material 7b in the front-end | tip part An apparatus may be used. In this case, even in the case of a small earthquake, the first and second seismic isolation devices 7 and 8 can exhibit a seismic isolation effect due to shear deformation.
[0050]
Further, the shapes of the first and second seismic isolation devices 7 and 8 are not limited to the circles shown in FIGS. 1 to 3 and 7, and any shape such as a square can be selected. The dust cover 9 may be provided between the fixing plates 5a and 5b, or may be separately provided between the fixing plates 5a and 5b and the connecting plate 6, or may be fixed to the upper and lower structures. One dustproof cover may be provided between the plates 5a and 5b.
[0051]
Further, with respect to the connecting plate 6, two fixing plates, ie, a fixing plate on which the first seismic isolation device 7 is fixed on the upper surface and a fixing plate on which the first seismic isolation device 7 is fixed on the lower surface are connected. Thus, the connecting plate 6 can also be configured. Further, when the fixing plates 5a and 5b are connected to each other, the fixing plates 5a and 5b may be directly connected by the bolts 13 without interposing the contact plate 12.
[0052]
【The invention's effect】
  As explained above, the multistage sliding composite seismic isolation unit according to claim 1 and the same are used.Claim 2Since the first seismic isolation device and the second seismic isolation device arranged in a plurality of stages via the connecting plate or the fixing plate are unitized in the vertical direction, Installation work is easy, so the construction period can be shortened and the construction cost can be reduced. Furthermore, the single composite seismic isolation unit can achieve both long period and high attenuation performance. In addition, since there is no risk of buckling during large deformations, a high seismic isolation effect can be exhibited from small earthquakes to large earthquakes, and the first and second seismic isolation devices By adjusting the plane cross-sectional area and arbitrarily setting the vertical load share in the first seismic isolation device, a multi-slip composite seismic isolation unit with optimal performance corresponding to the characteristics of the superstructure can be easily realized. can do.
[0053]
Furthermore, since the upper and lower first seismic isolation devices by the sliding support are provided in a plurality of stages, the length of the sliding plate with respect to the relative displacement of the upper and lower structure can be reduced, and the miniaturization of the unit can be achieved. Since the main body portion of the first seismic isolation device is fixed and integrated with the connecting plate, a large bending stress does not act on the connecting plate, and the sliding material is attached to the upper and lower structures. In order to slide on the fixing plate that is fixed and easily obtains high flatness, a desired seismic isolation effect can be obtained reliably, and the load of the upper structure can be reliably supported by the lower structure.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a multi-stage sliding composite seismic isolation unit of the present invention.
FIG. 2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a longitudinal sectional view showing a deformed state of the multi-stage sliding composite seismic isolation unit of FIG. 1 during a large earthquake.
FIG. 4 is a side view showing a relationship between a sliding amount and a sliding plate size in a case of general one-side sliding.
FIG. 5 is a side view showing the relationship between the sliding amount and the sliding plate size in the case of double-sided sliding.
6 is a side view showing the relationship between the amount of slip and the size of the sliding plate in the multi-stage sliding composite seismic isolation unit shown in FIG. 1. FIG.
FIG. 7 is a longitudinal sectional view showing a second embodiment of the multi-slip composite seismic isolation unit of the present invention.
[Explanation of symbols]
1 Foundation (substructure)
2 Building (superstructure)
3, 20 Multi-slip composite seismic isolation unit
4, 21 Combined seismic isolation unit
5a, 5b Fixing plate
6 Connecting plate
7 First seismic isolation device
7a Body
7b Sliding material
8 Second seismic isolation device
9 Dust-proof cover
10 Sliding board

Claims (2)

Each pair of fixing plates are fixed to the upper structure and the lower structure, and two or more connection plates arranged in these fixing plates, each other between these connecting plate and between the connecting plate and the fixing plate comprising a by sliding bearings which are provided by matching the axis first isolator and a second isolator by the elastic bearing provided between the connecting plates and the connecting plate and the fixing plate ,
The first seismic isolation device is configured such that a sliding member at a front end portion is slidably provided on the opposing fixing plate or the coupling plate by fixing each main body portion to the coupling plate. A featured multistage sliding composite seismic isolation unit. The seismic isolation device of the upper and lower structure between KaiSosu should axial force member, seismic isolation structure, wherein a multistage sliding composite seismic isolation unit according to claim 1 is provided.

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