JP2021103003A - Base isolation structure - Google Patents

Abstract

To provide a base isolation structure capable of improving damping property for earthquake force by increasing a coefficient of friction and suppressing excessive deformation of a base isolation layer by forming a tri-linear restoration force characteristic without complicating a structure and changing a constitution of a spherical slide device.SOLUTION: A base isolation structure 100 includes an integrated parallel base isolation device 50 constituted by arranging a spherical slide device 10 and a damper device 20 in parallel in a base isolation layer 65 between an upper structure 73 and a lower structure 63. On the other hand, a base isolation structure 100A includes a distributed parallel base isolation device 50D constituted by arranging the spherical slide device 10 and the damper device 20 in parallel on separated positions in the base isolation layer 65.SELECTED DRAWING: Figure 1

Description

The present invention relates to a seismic isolation structure.

A seismic isolation device is installed in the seismic isolation layer between the upper structure (for example, the upper frame) and the lower structure (for example, the foundation) of the building to form a seismic isolation structure, and the vibration during an earthquake is dampened or absorbed by the seismic isolation structure. By doing so, a seismic isolated building is being constructed that does not transmit seismic force to the superstructure as much as possible. The seismic isolation structure is generally formed by a seismic isolation device arranged directly under a pillar, for example, of an upper structure, and the seismic isolation device includes a seismic isolation device integrated with laminated rubber or a spherical surface. There are sliding seismic isolation devices such as sliding devices and flat sliding devices. The above-mentioned seismic isolation device aims to reduce the seismic force acting on the building by lengthening the vibration mode of the building vibration due to the earthquake in the horizontal direction.

When a spherical sliding device is applied among the above-mentioned seismic isolation devices, it has been common to form a seismic isolation structure by using only the spherical sliding device alone without using other seismic isolation devices. is there. Therefore, when adjusting the restoring force characteristics, in a double-sided sliding seismic isolation device (so-called double pendulum type spherical sliding device), the curvature of the sliding surface of the upper and lower sill, the curvature of the upper and lower sliding surfaces of the slider, and the friction coefficient. By adjusting, the rigid-plastic bilinear is adjusted. Further, when the restoring force characteristic of the trilinear is used, the outer upper sill and the outer lower sill are arranged on the upper and lower sides, and the inner upper sill and the inner lower sill and the slider are arranged between the outer upper sill and the outer lower sill. , A so-called triple pendulum type spherical sliding device is applied, but the triple pendulum type seismic isolation device has a problem that the structure becomes complicated.

In addition, it may be necessary to adjust the period of the secondary rigidity so that it does not resonate with a specific seismic wave, but in the spherical sliding device, the natural period is uniquely determined by the curvature of the upper and lower sill, so it is free. There is also the problem that adjustment is difficult.

From the above, the structure is not complicated, and by forming the restoring force characteristics of the trilinear without changing the configuration of the spherical sliding device, the friction coefficient is increased to improve the damping of the seismic force, and It is desired to develop a seismic isolation structure that can suppress excessive deformation of the seismic isolation layer.

Here, Patent Document 1 proposes a seismic isolation structure having a high degree of freedom in seismic isolation design. Specifically, it is a seismic isolation structure in which a laminated rubber bearing and a spherical sliding bearing are arranged between the substructure and the superstructure, and the laminated rubber bearing and the spherical sliding bearing are composed of the substructure and the superstructure. When they move relative to each other under a lateral load, they are arranged in parallel so as to be horizontally displaced.

Japanese Unexamined Patent Publication No. 2016-138592

The seismic isolation structure described in Patent Document 1 is a seismic isolation structure in which the laminated rubber and the spherical sliding bearing share 50% each of the vertical load of the superstructure and support it. On the premise of this, when a lateral load is applied during an earthquake, the spherical sliding bearing is vertically displaced at the same time as the horizontal displacement, so that the shared vertical load of the laminated rubber bearing is gradually transferred to the spherical sliding bearing. There is. With the shift of the shared vertical load of the laminated rubber bearing to the spherical sliding bearing, the initial shear force coefficient can be reduced as compared with the case where the spherical sliding bearing is a single bearing.

However, since the seismic isolation structure is such that the vertical load due to the superstructure is supported by the laminated rubber bearing and the spherical sliding bearing sharing 50% each, seismic isolation for both seismic isolation devices to share the load. It takes a lot of time and effort to design the arrangement of both sides in the layer, and it is necessary to precisely position both seismic isolation devices during the arrangement and construction, so it takes a lot of time and effort. In addition, since the laminated rubber bearing cannot follow the vertical displacement of the spherical sliding bearing in the first place, it is asked whether a seismic isolation structure having better restoring force characteristics than the restoring force characteristics of the spherical sliding bearing alone is actually formed. Is questionable.

The present invention has been made in view of the above problems, the structure is not complicated, and the friction coefficient is increased by forming the restoring force characteristic of the trilinear without changing the configuration of the spherical sliding device. The purpose is to provide a seismic isolation structure that can enhance the damping of seismic force and suppress excessive deformation of the seismic isolation layer.

In order to achieve the above object, one aspect of the seismic isolation structure according to the present invention is
In the seismic isolation layer between the upper structure and the lower structure, a spherical sliding device and a damper device are arranged in parallel.

According to this aspect, since the spherical sliding device and the damper device are arranged in parallel on the seismic isolation layer, the restoring force characteristic of the trilinear is obtained by synthesizing the restoring force characteristics of each bilinear possessed by the spherical sliding device and the damper device. However, the spherical sliding device is placed directly under the pillars and walls that make up the superstructure, and the damper device that does not generally support vertical loads can be placed in any position. Further, since the spherical sliding device and the damper device are arranged in parallel, it is possible to form a seismic isolation structure whose structure is not complicated. Such a seismic isolation device in which a spherical sliding device and a damper device are arranged in parallel is referred to as a "parallel seismic isolation device" in the present specification.

Here, in the form in which the spherical sliding device and the damper device are arranged in parallel, a form in which the spherical sliding device and the damper device are arranged in a plane separated from each other in the seismic isolation layer, or a spherical sliding device is used. By connecting the side surfaces of the upper and lower sill to be configured by the damper device, both the spherical sliding device and the damper device are integrated in parallel. In addition, the "seismic isolation layer" includes the basic seismic isolation layer between the building body, which is the upper structure, and the foundation, which is the lower structure (seismic isolation layer in the foundation seismic isolation), as well as the building that is the upper structure. An intermediate seismic isolation layer (seismic isolation layer in intermediate seismic isolation) between an upper upper frame (for example, a roof structure) and a lower upper structure (for example, a rising structure between a foundation and a roof structure) in which the upper structure is divided into upper and lower parts in the middle. ) Are included.

In the spherical sliding device, since both the lower and upper sill have a sliding surface having a curvature and a slider having a sliding surface having a curvature in the vertical direction, the seismic isolation structure has a horizontal load at the time of an earthquake. When received, the lower sill and the upper sill are horizontally displaced from each other via the slider, and the spherical sliding device is displaced in the vertical direction as a whole due to the slider sliding on the sliding surface having curvature. .. Unlike the laminated rubber bearing type seismic isolation device, the damper device can follow the vertical displacement of the spherical sliding device, and therefore both the spherical sliding device and the damper device when a horizontal load during an earthquake is applied. The bilinear restoring force characteristics of can be synthesized. According to the trilinear restoring force characteristics of the seismic isolation structure formed by this synthesis, for example, the friction coefficient can be increased as compared with the bilinear restoring force characteristics when the spherical sliding device is a single unit, and the seismic force (response). Acceleration and response shear force) damping performance is improved. Further, by imparting the rigidity of the damper device, the deformation amount of the spherical sliding device can be kept at the same level as the deformation amount of the spherical sliding device in the bilinear restoring force characteristic when the spherical sliding device is a single unit, and therefore the horizontal deformation is excessive. There is no risk of this occurring.

In addition, when forming a parallel seismic isolation device (with a seismic isolation structure) having trilinear restoring force characteristics, the curvatures of the sliding surfaces of the upper and lower sill that make up the spherical sliding device can be changed, and the upper and lower sill can be changed. There is no need for processing such as increasing the plane size of. That is, by imparting the rigidity of the damper device to the spherical sliding device, a seismic isolation structure having a small limit deformation amount is formed with respect to the limit deformation amount of the seismic isolation structure formed by the single spherical sliding device. it can.

Furthermore, although the laminated rubber bearing type seismic isolation device has a large temperature dependence, both the spherical sliding device and the damper device have a small temperature dependence, so that they are suitable for low temperature areas, for example, and against load changes due to snow cover in heavy snow areas. However, the seismic isolation performance is hard to change.

Further, in another aspect of the seismic isolation structure according to the present invention, the spherical sliding device has an upper sill and a lower sill and a slider that slides between them.
The damper device is a U-shaped damper.
The upper sill and the lower sill are connected by a plurality of U-shaped dampers arranged in the vertical direction or the vertical diagonal direction.

According to this aspect, the spherical sliding device and the U-shaped damper are arranged in parallel with each other by connecting a plurality of U-shaped dampers arranged in the vertical direction or the vertical diagonal direction on each side surface of the upper and lower sill. Since an integrated parallel seismic isolation device can be formed, the installation location of the seismic isolation device in the seismic isolation layer can be reduced as compared with the form in which both are arranged in parallel separately. The workability is improved and the number of footings to be installed at the installation site can be reduced, which leads to a reduction in construction cost.

The U-shaped damper (U-shaped damper rod) is made of steel and absorbs seismic energy by plasticizing the U-shaped damper rod. The U-shaped damper rod can be standardized by the shear deformation angle calculated by dividing the displacement amplitude of the positive and negative alternation during an earthquake by the height of the rod, and provides damping dampers of various sizes with various repeatability. be able to. The U-shaped damper is deformed so that the curved portion curved in the U-shape is displaced in the extending direction of the rod. At the time of this deformation, the point where the strain is maximized during plastic deformation is moved in the rod according to the change in the horizontal displacement amount, so that the strain of the rod is not locally concentrated and the entire rod is effectively effective. It is an excellent steel damper that uses it to absorb or attenuate seismic energy.

Here, "arranged in the vertical direction" means that the U-shaped damper is arranged in the vertical direction to connect each side surface of the upper sill and the lower sill, while "arranged in the vertical diagonal direction". "Arranged" means that the U-shaped damper is arranged in a state where each side surface of the upper sill and the lower sill is laid down in an oblique direction between the vertical direction and the horizontal direction, and each side surface of the upper sill and the lower sill is arranged. It means to connect.

Further, in another aspect of the seismic isolation structure according to the present invention, the spherical sliding device has an upper sill and a lower sill, and a slider that slides between them.
The damper device is a U-shaped damper.
An upper base plate and a lower base plate are arranged on the upper surface of the upper shoe and the lower surface of the lower shoe, respectively.
The upper base plate and the lower base plate are connected by a plurality of the U-shaped dampers.

According to this aspect, the spherical sliding device and the U are formed by connecting the upper base plate and the lower base plate, which are arranged on the upper surface of the upper shoe and the lower surface of the lower shoe, respectively, which constitute the spherical sliding device, by a plurality of U-shaped dampers. The mold dampers can be arranged in parallel with each other to form an integrated parallel seismic isolation device.

Further, in another aspect of the seismic isolation structure according to the present invention, the damper device is a U-shaped damper.
A plurality of U-shaped dampers are connected to the upper structure and the lower structure so as to straddle the spherical sliding device in the seismic isolation layer.

According to this aspect, by connecting the upper structure and the lower structure that sandwich the spherical sliding device at the top and bottom with a U-shaped damper, the general spherical sliding device is arranged in parallel with each other without any processing. It is possible to form a parallel seismic isolation device in which the spherical sliding device and the U-shaped damper are substantially integrated. In the case of foundation seismic isolation, both the lower footing (an example of the lower structure) installed in the seismic isolation pit and the spherical sliding device is placed and the upper footing (an example of the upper structure) connecting the underground beams. There is a form in which a U-shaped damper is connected.

Further, another aspect of the seismic isolation structure according to the present invention is characterized in that the spherical sliding device and the damper device are arranged in parallel at distant positions in the seismic isolation layer.

According to this aspect, since the spherical sliding device and the damper device are arranged in parallel at positions separated from each other in a plane, for example, when the spherical sliding device is greatly displaced during a large earthquake, the spherical sliding device and the damper device are arranged. The risk of mutual interference can be eliminated. The damper device represented by the U-shaped damper generally does not receive the vertical load from the superstructure and bears a part of the horizontal load at the time of an earthquake. Therefore, the spherical sliding device that supports the entire vertical load of the superstructure is arranged directly under the columns and walls that make up the superstructure, and the damper device is in a free position in the seismic isolation layer. It can be arranged. In this way, the laminated rubber bearing type seismic isolation device and the damper device that support the vertical load from the superstructure are significantly different in that they do not support the vertical load and can be arranged at any position in the seismic isolation layer. ..

As can be understood from the above description, according to the seismic isolation structure of the present invention, the structure is not complicated, and friction is formed by forming the restoring force characteristics of the trilinear without changing the configuration of the spherical sliding device. It is possible to provide a seismic isolation structure capable of increasing the coefficient to improve the damping property of the seismic force and suppressing excessive deformation of the seismic isolation layer.

It is a side view of an example of a seismic isolation building provided with a seismic isolation structure according to the first embodiment. It is a top view of an example of the integrated parallel seismic isolation device which forms the seismic isolation structure which concerns on 1st Embodiment. FIG. 2 is a view taken along the line III-III of FIG. 2, which is a side view of an example of an integrated parallel seismic isolation device. It is a top view of another example of the integrated parallel seismic isolation device which forms the seismic isolation structure which concerns on 1st Embodiment. It is a VV arrow view of FIG. 5, and is a side view of another example of the integrated parallel seismic isolation device. It is a top view of the other example of the integrated parallel seismic isolation device which forms the seismic isolation structure which concerns on 1st Embodiment. It is a VII-VII arrow view of FIG. It is a top view of the other example of the integrated parallel seismic isolation device which forms the seismic isolation structure which concerns on 1st Embodiment. It is an arrow view of IX-IX of FIG. This is an example of a displacement-friction coefficient graph showing the restoring force characteristics of a parallel seismic isolation device. It is a side view of an example of a seismic isolation building provided with a seismic isolation structure according to the second embodiment.

Hereinafter, the seismic isolation structure according to each embodiment will be described with reference to the attached drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Seismic isolation structure according to the first embodiment and a seismic isolated building having a seismic isolation structure]
First, with reference to FIGS. 1 to 10, the seismic isolation structure according to the first embodiment and a plurality of examples n parallel seismic isolation devices forming the seismic isolation structure will be described. Here, FIG. 1 is a side view of an example of a seismic isolated building having a seismic isolated structure according to the first embodiment. 2 and 3 are views for explaining an example of the integrated parallel seismic isolation device forming the seismic isolation structure according to the first embodiment, and FIGS. 4 and 5 are views for explaining an example of the seismic isolation device according to the first embodiment. 6 is a diagram illustrating another example of the integrated parallel seismic isolation device forming the structure, and FIGS. 6 and 7 and 8 and 9 respectively show an integrated parallel seismic isolation structure forming the seismic isolation structure according to the first embodiment. It is a figure explaining still another example of an apparatus.

The seismic isolation building 70 in the illustrated example has a seismic isolation pit 60 formed by excavating the ground G under the ground surface, and is parallel to the seismic isolation layer 65 between the seismic isolation pit 60 and the seismic isolation building 70. The building is provided with the device 50, and the seismic isolation structure 100 is formed by a plurality of parallel seismic isolation devices 50 arranged on the seismic isolation layer 65.

The seismic isolation pit 60 has a pit bottom 61 made of reinforced concrete, and a retaining wall 62 that is continuous with the pit bottom 61 and resists the earth pressure and the earth water pressure of the surrounding ground G. A lower footing 63 (an example of a lower structure) is projected upward at a position corresponding to a pillar 76 constituting the upper frame 75 on the upper surface of the pit bottom board 61, and parallel seismic isolation is provided on the upper surface of the lower footing 63. The device 50 is mounted. A gap S is provided between the retaining wall 62 and the parallel seismic isolation device 50 at the end so that the upper frame 75 and the retaining wall 62 do not collide with each other via the parallel seismic isolation device 50, for example, in the event of a large earthquake. There is.

The parallel seismic isolation device 50 is formed by arranging the spherical sliding device 10 and the damper device 20 in parallel, and the upper surface of the parallel seismic isolation device 50 is a lower structure made of reinforced concrete provided at the lower end of the upper frame 75. The body 71 is arranged. The lower structure 71 has an underground beam 72 arranged in a grid pattern and an upper footing 73 (an example of the upper structure) provided at the points of the grid-shaped central beams 72 in various places, and is parallel to each other. An upper footing 73 is arranged on the upper surface of the seismic isolation device 50. Here, the upper frame 75 may be any of S structure (steel frame structure), RC structure (steel reinforced concrete structure), and SRC structure (steel reinforced concrete structure).

A column 76 constituting the upper frame 75 is erected directly above the upper footing 73. Therefore, the vertical load by the upper frame 75 is loaded on the parallel seismic isolation device 50 via the column 76 and the upper footing 73. Will be done.

The parallel seismic isolation device 50 forming the seismic isolation structure 100 according to the first embodiment is an integrated parallel seismic isolation device in which a spherical sliding device 10 and a damper device 20 are integrated. There are various forms. Hereinafter, each form of the integrated parallel seismic isolation device will be described with reference to FIGS. 2 to 9.

First, in the integrated parallel seismic isolation device 50 shown in FIGS. 2 and 3, a plurality of Us in which the side surfaces of the upper shoe 11 and the lower shoe 15 constituting the spherical sliding device 10 are arranged in the vertical direction (or the vertical direction) are arranged. A mold damper 20 (an example of a damper device) is connected.

The spherical sliding device 10 has an upper shoe 11, a lower shoe 15, and a slider 18 that slides between the upper shoe 11 and the lower shoe 15. Both the upper sill 11 and the lower sill 15 are plate materials having a rectangular shape in a plan view (square in the illustrated example), and are formed of rolled steel materials for welding steel materials (SM490A, B, C, or SN490B, C, or S45C). There is. The lower surface of the upper shoe 11 and the upper surface of the lower shoe 15 are provided with curved sliding surfaces 12 and 16, respectively, and a stainless steel sliding plate (not shown) is fixed to the sliding surfaces 12 and 16, respectively. Has been done. Further, a stopper ring 17 for preventing the slider 18 from falling off is fixed to the upper shoe 11 and the lower shoe 15 on the outer periphery of the sliding plate.

On the other hand, the slider 18 includes upper and lower sliding surfaces 19 having a curvature, and has a substantially columnar shape. Further, the slider 18 is formed of rolled steel for welding steel (SM490A, B, C, or SN490B, C, or S45C) and has a load bearing strength of about 60 N / mm2 (60 MPa).

At least a friction material (not shown) made of PTFE is attached to the upper and lower sliding surfaces 19 of the slider 18. The friction material is formed of a double woven fabric, and the double woven fabric is formed of PTFE fibers and fibers having a higher tensile strength than the PTFE fibers (high-strength fibers). Here, "fibers having higher tensile strength than PTFE fibers" include polyamides such as nylon 6.6, nylon 6, nylon 4.6, polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene na. Examples include polyesters such as phthalate and fibers such as paraaramid. In addition, fibers such as metaalamide, polyethylene, polypropylene, glass, carbon, polyphenylene sulfide (PPS), LCP, polyimide, and PEEK can be mentioned. Further, heat-sealed fibers and fibers such as cotton and wool may be applied. Among them, PPS fibers having excellent chemical resistance and hydrolysis resistance and extremely high tensile strength are desirable. At least, the friction material made of PTFE may be a woven material containing PTFE fibers other than the double woven fabric, a friction material made of only PTFE as a material, and a friction material made of a composite material of PTFE and another resin. It may be a friction material having a laminated structure of a friction material made of PTFE as a material and a friction material made of another resin as a material.

U-shaped dampers 20 arranged in the vertical direction connect the four corresponding corners of the upper and lower stiles 11 and 15 of the plan view square. More specifically, steel mounting pieces 30 are fixed to the corners of the upper and lower stiles 11, and the upper and lower ends of the U-shaped damper 20 are bolts 35 to the upper and lower mounting pieces 30. Be joined.

The U-shaped damper 20 is formed by an upper and lower straight rod 22 and a curved rod 21 having a predetermined curvature continuous with the upper and lower straight rod 22.

As is clearly shown in FIG. 3, U-shaped dampers 20 are arranged in parallel on the side of the spherical sliding device 10, and both are bolted to form an integrally parallel seismic isolation device 50.

Returning to FIG. 1, the seismic isolation structure 100 is formed by disposing the integrally parallel seismic isolation device 50 between the plurality of sets of the lower footing 63 and the upper footing 73 in the seismic isolation layer 65.

Next, in the integrated parallel seismic isolation device 50A shown in FIGS. 4 and 5, a plurality of U-shaped dampers 20A in which the side surfaces of the upper and lower stiles 15 constituting the spherical sliding device 10 are arranged in the vertical and oblique directions are arranged. (An example of a damper device) is connected.

A U-shaped damper 20A arranged in an oblique vertical direction connects the four corresponding side surfaces of the upper and lower stiles 11 and 15 of the square view in a plan view. More specifically, steel mounting pieces 30A are fixed to the side surfaces of the upper and lower stiles 11 at a predetermined oblique angle, and the upper and lower ends of the U-shaped damper 20A are bolted to the upper and lower mounting pieces 30A. Joined at 35.

The performance of the U-shaped damper 20A is determined by the plate thickness and the total length, and the total length depends on the curvature of the curved rod 21. Therefore, the U-shaped damper 20A having a predetermined curvature naturally has a certain height or more. become. On the other hand, when the height between the upper shoe 11 and the lower shoe 15 constituting the spherical sliding device 10 is lower than the height of the U-shaped damper 20A, the U-shaped damper 20A is arranged in the vertical direction (vertical direction). , U-shaped damper 20A cannot be connected to both side surfaces of the upper sill 11 and the lower sill 15.

In such a case, by arranging the U-shaped damper 20A in the vertical and diagonal directions as in the integrally parallel seismic isolation device 50A shown in the figure, the vertical height of the U-shaped damper 20A is substantially lowered while the upper sill is used. It is possible to connect the U-shaped damper 20A to both the side surfaces of the 11 and the lower sill 15.

Next, the integrated parallel seismic isolation device 50B shown in FIGS. 6 and 7 is above a rectangular shape in a plan view (a square in the illustrated example) on the upper surface of the upper shoe 11 and the lower surface of the lower shoe 15 constituting the spherical sliding device 10, respectively. A base plate 40A and a lower base plate 40B are arranged, and a U-shaped damper 20 connects the corresponding side surfaces of the upper base plate 40A and the lower base plate 40B to each other.

The ends of the U-shaped damper 20 are connected to the upper base plate 40A and the lower base plate 40B via bolts 35. Although not shown, when the integrally parallel seismic isolation device 50B is arranged on the seismic isolation layer 65, the lower surface of the upper footing 73 is brought into contact with the upper surface of the upper base plate 40A, and the lower footing 63 is brought into contact with the lower surface of the lower base plate 40B. The upper surface of the is abutted.

Next, the integrated parallel seismic isolation device 50C shown in FIGS. 8 and 9 has a spherical surface between the lower footing 63 and the upper footing 73 on the upper surface of the upper foot 11 and the lower surface of the lower foot 15 constituting the spherical sliding device 10, respectively. A sliding device 10 is arranged, and a plurality of U-shaped dampers 20 connect the lower footing 63 and the upper footing 73 across the spherical sliding device 10.

A flange piece 31 is fixed to the end of the mounting piece 30B, and the flange piece 31 is fixed to the side surface of the lower footing 63 or the upper footing 73 via a bolt 35, and is U with respect to the corresponding upper and lower mounting pieces 30B. The ends of the mold damper 20 are connected via bolts 35.

In the integrated parallel seismic isolation device 50C, the spherical sliding device 10 and the U-shaped damper 20 are not directly connected, but as is clear from FIG. 9, the spherical sliding device 10 and the U-shaped damper 20 are substantially integrated. Since it is a parallel seismic isolation device, it shall be included in the integrated parallel seismic isolation device.

Next, the restoring force characteristics of the integrated parallel seismic isolation devices 50, 50A, 50B, and 50C will be described with reference to FIG. Here, FIG. 10 is an example of a displacement-friction coefficient graph showing the restoring force characteristics of the parallel seismic isolation device.

In FIG. 10, the dotted line is a graph showing the restoring force characteristics of the spherical sliding device, the alternate long and short dash line is a graph showing the restoring force characteristics of the damper device (U-shaped damper), and the solid line is a composite of the restoring force characteristics of both. It is a graph which shows the restoring force characteristic of the integrated parallel seismic isolation device.

The spherical sliding device 10 is exempt from the fact that the upper sill 11 and the lower sill 15 both have the sliding surfaces 12 and 16 having curvatures and the slider 18 having the sliding surfaces 19 having curvatures in the vertical direction. When each of the integrated parallel seismic isolation devices 50 to 50C constituting the seismic structure 100 receives a horizontal load at the time of an earthquake, the upper sill 11 and the lower sill 15 are horizontally displaced from each other via the slider 18 to provide a curvature. The spherical sliding device 10 is displaced in the vertical direction as a whole due to the slider 18 sliding on the sliding surfaces 12 and 16. Unlike the laminated rubber bearing type seismic isolation device, the damper devices 20 and 20A can follow the vertical displacement of the spherical sliding device 10, and therefore, when a horizontal load during an earthquake is applied, the spherical sliding device 10 And the bilinear restoring force characteristics of both the damper devices 20 and 20A can be combined, and the trilinear restoring force characteristics of the illustrated example can be formed.

In FIG. 10, when a horizontal load during an earthquake is applied, the integrated parallel seismic isolation devices 50 to 50C do not displace up to a friction coefficient of μ0, and are integrated with the horizontal load during an earthquake when the friction coefficient exceeds μ0. The damping performance of the parallel seismic isolation devices 50 to 50C is exhibited. Then, the horizontal load at the time of an earthquake is reduced according to the trilinear restoring force characteristics of the integrated parallel seismic isolation devices 50 to 50C.

According to the restoring force characteristics of the trilinear in the illustrated example, the friction coefficient can be increased from μ2 to μ3 as compared with the restoring force characteristics of the bilinear when the spherical sliding device 10 is a single unit, and the seismic force (response acceleration and response acceleration) can be increased. The damping performance of the response shear force) is improved. Further, due to the rigidity of the damper devices 20 and 20A, the amount of deformation of the integrally parallel seismic isolation devices 50 to 50C is about the same as the amount of deformation of the spherical sliding device 10 in the bilinear restoring force characteristics when the spherical sliding device 10 is a single unit. The amount of deformation can be limited, and therefore there is no risk of excessive horizontal deformation.

Further, when forming the seismic isolation structure 100 having the restoring force characteristic of the trilinear, the curvatures of the sliding surfaces 12 and 16 of the upper sill 11 and the lower sill 15 constituting the spherical sliding device 10 can be changed, or the upper sill 11 and the lower sill can be changed. There is no need for processing such as increasing the plane dimension of 15. That is, by imparting the rigidity of the damper devices 20 and 20A to the spherical sliding device 10, the limit deformation amount is smaller than the limit deformation amount of the seismic isolation structure formed by the single spherical sliding device 10. A seismic isolation structure can be formed. If the limit deformation amount is large, the ratio of the height and the diameter of the slider constituting the spherical sliding device also becomes large, and it becomes necessary to increase the diameter of the slider, which is not preferable.

According to the illustrated seismic isolation structure 100, since a seismic isolation device having a complicated structure such as a triple pendulum type seismic isolation device is not applied, the structure is not complicated and the configuration of the spherical sliding device 10 is changed. However, by forming the restoring force characteristic of the trilinear, the friction coefficient can be increased to enhance the damping property of the seismic force, and the excessive deformation of the seismic isolation layer 65 can be suppressed.

[Seismic isolation structure according to the second embodiment and a seismic isolation building having a seismic isolation structure]
Next, an example of the seismic isolation structure according to the second embodiment will be described with reference to FIG. Here, FIG. 11 is a side view of an example of a seismic isolated building having a seismic isolated structure according to the second embodiment.

The illustrated seismic isolation structure 100A has a distributed parallel seismic isolation device 50D in which the spherical sliding device 10 and the damper device 20A are arranged in parallel at positions separated in a plane in the seismic isolation layer 65. Different from 100.

The damper device 20B constituting the distributed parallel seismic isolation device 50D is formed by connecting a plurality of damper rods 24 to the upper and lower base plates 25. For example, the damper device 20A is formed by connecting the four side surfaces or the four corners of the upper and lower base plates 25 of the square in a plan view with the four damper rods 24 via bolts.

As is clearly shown in FIG. 11, the spherical sliding device 10 that supports the vertical load of the upper frame 75 is arranged directly below the pillar 76 that forms the upper frame 75. On the other hand, the damper device 20A does not support the vertical load of the upper frame 75, but bears a part of the horizontal load at the time of an earthquake. Therefore, the number of damper devices 20A that can obtain the desired trilinear restoring force characteristics together with the spherical sliding device 10 can be arranged at any position of the seismic isolation layer 65. The distributed parallel seismic isolation device 50D also has the trilinear restoring force characteristic shown in FIG. 10, like the integrated parallel seismic isolation device 50 and the like.

Even with the seismic isolation structure 100A shown in the figure, since a seismic isolation device having a complicated structure such as a triple pendulum type seismic isolation device is not applied, the structure is not complicated and the configuration of the spherical sliding device 10 is not changed. By forming the restoring force characteristic of the trilinear, the friction coefficient can be increased to enhance the damping property of the seismic force, and the excessive deformation of the seismic isolation layer 65 can be suppressed.

It should be noted that the configuration or the like described in the above embodiment may be another embodiment in which other components are combined, and the present invention is not limited to the configuration shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

10: Spherical sliding device 11: Upper sill 12: Sliding surface 15: Lower sill 16: Sliding surface 17: Stopper ring 18: Slider 19: Sliding surface 20, 20A, 20B: Damper device (U-shaped damper)
21: Curved rod 22: Straight rod 24: Damper rod 25: Base plate 30, 30A, 30B: Mounting piece 35: Bolt 40A: Upper base plate 40B: Lower base plate 50, 50A, 50B, 50C: Parallel seismic isolation device Seismic isolation device)
50D: Parallel seismic isolation device (distributed parallel seismic isolation device)
60: Seismic isolation pit (substructure)
61: Pit bottom 62: Retaining wall 63: Lower footing 65: Seismic isolation layer 70: Seismic isolation building 71: Substructure 72: Underground beam 73: Upper footing 75: Upper frame 76: Pillar 100, 100A: Seismic isolation structure G: Local S: Gap

Claims (5)

A seismic isolation structure characterized in that a spherical sliding device and a damper device are arranged in parallel in a seismic isolation layer between an upper structure and a lower structure. The spherical sliding device has an upper sill and a lower sill, and a slider that slides between them.
The damper device is a U-shaped damper.
The seismic isolation structure according to claim 1, wherein a plurality of the U-shaped dampers arranged in a vertical direction or an oblique vertical direction are connected to the upper shoe and the lower shoe. The spherical sliding device has an upper sill and a lower sill, and a slider that slides between them.
The damper device is a U-shaped damper.
An upper base plate and a lower base plate are arranged on the upper surface of the upper shoe and the lower surface of the lower shoe, respectively.
The seismic isolation structure according to claim 1, wherein a plurality of the U-shaped dampers are connected to the upper base plate and the lower base plate. The damper device is a U-shaped damper.
The seismic isolation structure according to claim 1, wherein a plurality of U-shaped dampers are connected to the upper structure and the lower structure across the spherical sliding device in the seismic isolation layer. .. The seismic isolation structure according to claim 1, wherein in the seismic isolation layer, the spherical sliding device and the damper device are arranged in parallel at distant positions.

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