JP3029111U - Seismic isolation support - Google Patents

Abstract

(57) [Abstract] [Problem] To improve the durability of seismic isolation bearings,
Aim for miniaturization. SOLUTION: An upper member 2 fixed to a structure S and a foundation B
A slide bearing 4 composed of a lower member 3 fixed to the lower member 3, and a plurality of torsion members fixed to the peripheral side surface of the cylindrical portion 3b formed on the lower member 3 and extending in the tangential direction of the cylindrical portion 3b And an engaging portion 5a is formed by bending the free end of the torsion bar 5 upward, and at a position corresponding to the engaging portion 5a of the upper member 2,
An engagement long hole 6 with which the engagement portion 5a engages is formed, and the long axis direction of the engagement long hole 6 coincides with the longitudinal direction of the torsion bar 5.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to seismic isolation bearings. More specifically, sliding bearings and mainly horizontal bearings are used between the structures such as buildings and bridges and their foundations, and / or for the purpose of seismic isolation / control of the structures by interposing them between the two structures. Regarding seismic isolation bearings with directional reaction mechanism.

[0002]

[Prior art]

 From the standpoint of seismic isolation, the seismic isolation bearing is ideally a horizontal mechanical relationship between the foundation and the structure so that the vibration of the foundation is not transmitted to the structure mounted on the foundation. It is good that it is cut off. However, in reality, there are restrictions due to other conditions, and such a structure is almost impossible, and the aim is to support the bearing so that the horizontal relative displacement between the foundation and the structure during vibration can be as large as possible. Is.

Conventionally, as a seismic isolation bearing for a building or the like, as shown in FIG. 4, a sliding bearing which receives a vertical load of the building and a horizontal movement (displacement due to vibration) of the building are elastically suppressed. It is known that the reaction mechanism and the reaction mechanism are configured separately.

The sliding bearing 52 in the seismic isolation bearing 51 shown in FIG. 4 has a Teflon coating or the like between the upper shoe 52a fixed to the structure S side and the lower shoe 52b fixed to the foundation B side. It is made to be slidable. In the figure, the range indicated by the diameter Ds is the sliding surface. The reaction mechanism 53 includes upper and lower mounting members 54a and 54b whose upper and lower ends are fixed to the building S side and the foundation B side, and a rubber member 55 fixed between these mounting members. The building S is installed so that it receives almost no vertical load. Hereinafter, this seismic isolation bearing 51 will be referred to as "prior art 1".

In addition to the seismic isolation bearing 51, it is necessary to use a reaction force mechanism made of laminated rubber having a high damping property, and the reaction force mechanism also supports the vertical load of the building so that a slide bearing is additionally provided. Seismic isolation bearings that have lost their properties are also known (hereinafter, this seismic isolation bearing is referred to as Prior Art 2).

Further, Japanese Patent Laid-Open No. 2-107843 discloses a seismic isolation bearing in which a slide bearing is separately provided and a compression coil spring is interposed between a foundation and a structure as a reaction force mechanism. (Hereinafter, this seismic isolation bearing is referred to as Prior Art 3).

[0007] Further, in Japanese Patent Laid-Open No. 1-83744, it is expected that a building and a foundation will be combined with each other in the expectation that a horizontal reaction mechanism and a vertical reaction mechanism will be provided without providing a sliding bearing. A seismic isolation bearing having a plurality of magnets that exert a magnetic force horizontally and vertically is disclosed (hereinafter, this seismic isolation bearing is referred to as Prior Art 4).

[0008]

[Problems to be solved by the device]

 However, in the prior art 1 and the prior art 3, since the sliding bearing and the reaction force mechanism are separately formed, a considerably large space is required to mount such a seismic isolation bearing. Furthermore, since the reaction force mechanism is made of rubber, deterioration inevitably reduces life.

In addition, although the installation space is small in the prior art 2, since the vertical load of the building is supported by the rubber member, deterioration and deformation are promoted.

Next, regarding the conventional technique 3, considering that the relative displacement in the horizontal direction between the foundation and the building is as large as possible as described above, it is necessary to use a coil panel with a large expansion and contraction margin. It requires a very large space. Furthermore, in coil springs and leaf springs, a larger space is required if the deformation is designed to be within the range where the spring is not damaged.

In addition, in the prior art 4, a magnet is required to support the vertical load of the building in a non-contact manner, in that case, a nearby magnetic material is greatly affected, and the building is supported. There are problems such as instability, which is not realistic.

[0012]

[Means for Solving the Problems]

 The present invention has been made to solve the above problems, and by disposing a plurality of torsion bars around the circumference of a slide bearing, the present invention is provided between a foundation and a structure and / or two structures. This is intended for a seismic isolation bearing that absorbs the relative displacement and damps the vibration by causing an elastic torsional reaction force of the torsion bar when a relative displacement occurs between the objects. With this configuration, a seismic isolation bearing that has excellent durability and can be downsized is realized.

[0013]

[Embodiment of device]

 The seismic isolation bearing of the present invention is a seismic isolation bearing interposed between a structure and a foundation and / or between two structures, wherein the upper structure and the foundation or the lower structure are A first member fixed to any one of the above, a second member fixed to the other and capable of sliding relative to the first member, and a plurality of radially fixed members on a side surface of the first member. A torsion bar, a first engaging portion is formed on the free end side of the torsion bar, and the first engaging portion is engaged with the second engaging portion of the second member. , The relative movement of the first engagement portion and the second engagement portion is allowed only in the longitudinal direction of the torsion bar, and the torsion bar is twisted by the relative movement in the other direction. It is configured to be engaged.

Therefore, if there is a relative displacement between the foundation side or the lower structure side and the upper structure side due to vibration or the like in the horizontal direction, the displacement of the torsion bar whose longitudinal direction coincides with the displacement direction Since it is not constrained, not only the torsional force but also the bending force is theoretically not applied. On the other hand, in the above relative displacement, with respect to the torsion bar in which the displacement direction and the longitudinal direction thereof do not coincide with each other, a load of a component in the horizontal direction which is perpendicular to the longitudinal direction is applied to the first engaging portion thereof. The load causes the torsion bar to be twisted. The elastic torsional reaction force at that time causes a damping action such as vibration.

As described above, since the torsion bar is arranged on the side surface of the first member, this seismic isolation bearing is formed to be very compact.

In this seismic isolation bearing, if the first member is fixed to the foundation side or the lower structure side, the first engaging portion of the torsion bar is engaged to the upper structure side. The free end is engaged with the base side or the lower side of the structure if it is assembled and, conversely, is fixed to the upper side of the structure.

The term “between the structure and the foundation” in the claims for utility model registration includes the space between the building and the foundation in the case of a general building, for example, in a bridge or the like. Means to include the space between the bridge girder and the pier. In short, it means between the object that receives vibration and the like and the object that tries to prevent the transmission of such vibration as much as possible.

In such seismic isolation bearing, when the first member is formed in a substantially cylindrical shape and a plurality of torsion bars are radially extended on the side surface of the first member, the radial direction or the tangential direction of the first member Can be attached to. Of course, in the present invention, it is not necessary to limit to either the radial direction or the tangential direction, and it is also possible to extend in the direction, that is, in the direction that forms an angle of more than 0 ° and less than 90 ° with respect to the radius. However, it is particularly preferable that the seismic isolation bearings be extended substantially tangentially because the seismic isolation bearing can be made more compact. Further, all of the plurality of torsion bars are not limited to be extended in the same angle direction, and torsion bars extended at different angles may be combined.

As described above, the radial shape in the scope of utility model registration claims means not only the radial direction but also the direction forming an angle of 0 ° to 90 ° with respect to the radius.

In addition, the term “substantially columnar” in the scope of claims for utility model registration is not limited to those having a circular cross section, and for example, a polygonal column such as a hexagonal column or an octagonal column. , A cylinder having an elliptical cross section, and the like.

Further, the first engaging portion is formed so as to extend from the free end of each torsion bar toward the second member side, and the second engaging portion is engaged with the first engaging portion. It is preferable that it is formed of a long hole for forming the long hole and the long axis direction of the long hole coincides with the longitudinal direction of the torsion bar because the above-mentioned action can be achieved with a very simple structure.

[0022]

【Example】

 Hereinafter, the seismic isolation bearing of the present invention will be described with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of the seismic isolation bearing of the present invention, FIG. 2 (a) is a plan view of the seismic isolation bearing of FIG. 1, and FIG. 2 (b) is a partial sectional front view. FIG. 3 is a partially sectional front view showing another embodiment of the seismic isolation bearing of the present invention.

As shown in FIG. 1 and FIG. 2, in the seismic isolation bearing 1 of this embodiment, the slippage is caused by the upper member 2 fixed to the upper structure S and the lower member 3 fixed to the foundation B. Bearing 4 is configured. The upper member 2 and the lower member 3 are formed with sliding surfaces 2a and 3a, respectively. Both sliding surfaces 2a, 3a are made of a known Teflon-finished surface or a stainless steel finished to a smooth surface.

Further, a plurality of torsion bars 5 are arranged on the peripheral side surface of the cylindrical portion 3b formed in the central portion of the lower member 3 so as to extend tangentially and horizontally to the cylindrical portion 3b. . The base of each torsion bar 5 is pressed into a radial hole (not shown) of the cylindrical portion 3b, or is fixed by welding or the like, and the free end thereof is bent substantially straight upward. The engaging portion 5a is formed. All the torsion bars 5 have engagement portions 5a having substantially the same length, and horizontal portions 5b have substantially the same length. Therefore, as shown in FIG. 2A, the engaging portions 5a of all the torsion bars 5 are located on the same circle C.

On the other hand, on the upper member 2, engagement long holes 6 are formed at positions on a circle corresponding to the circle C, the number of which corresponds to the number of the torsion bars 5. The engaging elongated hole 6 is formed so that the vicinity of the tip of the engaging portion 5a of the torsion bar 5 engages, and its major axis direction is aligned with the direction of the horizontal portion 5b of the corresponding torsion bar 5. I am doing it. That is, they coincide with the tangential direction of the cylindrical portion 3b of the lower member 3. Normally, when the centers of the upper member 2 and the lower member 3 are coincident with each other, the engaging portion 5a is engaged so as to be located at the center of the engaging elongated hole 6.

The circle C shown in FIG. 2A has a tangential direction as in this embodiment, as compared with the case where the torsion bar 5 is extended in the radial direction of the cylindrical portion 3b (not shown). The smaller the diameter, the smaller the overall size of the seismic isolation bearing 1.

Therefore, the structure S and the foundation B are displaced relative to each other in the longitudinal direction of the horizontal portion 5b of the torsion bar 5 (hereinafter, simply referred to as longitudinal direction) (therefore, the relative displacement between the upper member 2 and the lower member 3). For example, the load due to the relative displacement is not applied to the torsion bar 5 only by the movement of the engaging portion 5a in the engaging elongated hole 6. However, when the direction of relative displacement deviates from the longitudinal direction of the torsion bar 5, a load of a component in the direction perpendicular to the longitudinal direction is applied to the engaging portion 5a, and the length of the engaging portion 5a becomes approximately the arm length thereof. A moment is generated, and the torsion bar 5 is twisted around the axis of the horizontal portion 5b. For example, in FIG. 2A, when the relative displacement is made in the direction of arrow A, the torsional force is not applied to some of the torsion bars 25 and 35, but to the other torsion bars 5 from the upper member 2 respectively. A twisting force having a magnitude corresponding to the longitudinal direction of the is applied.

The stresses generated by the twisting force are combined to form an elastic resistance force against relative displacement due to vibration or the like. Of course, a slight bending force is also applied to the engaging portion 5a, and the stress against this also becomes an elastic resistance force against relative displacement.

In order to allow a larger relative displacement between the structure S and the foundation B, the major axis length of the engagement slot 6 and the length of the engagement part 5a may be increased. The material of the torsion bar 5 and the ratio of the shaft diameter to the length of the horizontal portion 5b may be selected accordingly. Further, the engagement elongated hole 6 absorbs the energy of the external force by causing the torsion bar to be plastically deformed when the vibration having a stronger strength than expected is applied. Thereby, a large relative displacement can be prevented.

Next, the material used for the torsion bar is preferably carbon steel, alloy steel, steel such as stainless steel, or aluminum alloy, from the viewpoint of weather resistance and the like. Carbon steel or the like is preferably subjected to anticorrosion treatment such as plating. A circular cross section is the most suitable shape for the torsion bar.

Next, in the seismic isolation bearing 11 shown in FIG. 3, the torsion bars 5 are installed in a state where they are arranged in the vertical direction every three bars. This is because, when a large number of torsion bars 5 are installed, if they are installed on the same circumference at the same height as shown in FIGS. 1 and 2, the installation space is insufficient on the side surface of the cylindrical portion 3b. When a plurality of torsion bars 5 are arranged on a vertical line as shown in FIG. 3, it is desirable that the extension angle with respect to the radius of the cylindrical portion 3b and / or the length of the torsion bar 5 be different. Further, the arrangement is not particularly limited to the arrangement on the vertical line, and it may be slightly shifted in the horizontal direction on the side surface of the cylindrical portion 3b.

Next, under the same external force condition, the seismic isolation bearing according to the embodiment of the present invention will be described in comparison with a conventional technique (hereinafter, referred to as a comparative example).

(Example) The supporting weight was set to 600 tons, the target natural period was set to 1.0 second, and the horizontal relative displacement was set to 12.3.

Under such a condition, if a sliding bearing having a sliding surface with a diameter Ds = 900 mm is applied as shown in FIG. 2, a steel torsion bar 5 having a length of 1000 mm and a shaft diameter of 40 mm is provided around the sliding bearing. You only need to install 100 of them. In that case, the outer diameter Do (Fig. 2) of the seismic isolation bearing 1 is 2340 mm.

(Comparative Example) When the same external force condition as that of the above-mentioned embodiment is set, if a sliding bearing 52 having a sliding surface with a diameter Ds = 900 mm is applied as shown in FIG. 4, the spring constant is about 12.16 t. A reaction force mechanism 53 using a laminated rubber 55 of onf / cm (a cylindrical shape having a diameter Dd = 900 mm) is required. As a result, the outer diameter Do1 of the sliding bearing 52 becomes 1350 mm and the outer diameter Do2 of the reaction force mechanism 53 becomes 1300 mm.

As described above, the seismic isolation bearing 1 according to the embodiment is more compact than the conventional art under the same conditions. Above all, due to the excellent weather resistance of the metal torsion bar as compared with rubber, the seismic isolation bearing 1 of this embodiment has a much longer life than the prior art.

When the coil spring described in the section of the prior art is used as a reaction force mechanism, a coil spring having an outer diameter of 300 mm and a free length of 400 mm is used under the same external force conditions as those of the above Examples and Comparative Examples. It is necessary to install 10 in parallel in one direction in plan view. From this point, it is clear that it is extremely difficult to make the reaction force mechanism compact. Furthermore, considering that the reaction force mechanism needs to cope with displacement in two orthogonal directions at least in the horizontal plane, it can be said that seismic isolation bearings using coil springs are unrealistic.

[0039]

[Effect of device]

 The seismic isolation bearing of the present invention has excellent durability and can be downsized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a base isolation bearing of the present invention.

2 (a) is a plan view of the seismic isolation bearing of FIG. 1, and FIG. 2 (b) is a partial sectional front view.

FIG. 3 is a partially sectional front view showing another embodiment of the seismic isolation bearing of the present invention.

FIG. 4 shows an example of a conventional seismic isolation bearing, FIG. 4 (a) is a plan view thereof, and FIG. 4 (b) is a front view thereof.

[Explanation of symbols]

 1 ... Seismic isolation bearing 4 ... Slip bearing 5 ... Torsion bar 5a ... Engagement part 6 ... Elongation hole 11 ... Seismic isolation bearing 25 ... Torsion bar 35 ...・ Torsion bar S ・ ・ ・ Structure B ・ ・ ・ Basic

Claims (4)

[Scope of utility model registration request] 1. A seismic isolation bearing which is interposed between a structure and a foundation and / or between two structures,
A first member fixed to any one of the upper structure side and the foundation or the lower structure side, and a second member fixed to the other and capable of sliding relative to the first member, A plurality of torsion bars radially fixed to a side surface of the first member, a first engaging portion is formed at a free end of the torsion bar, and the first engaging portion is The second engaging portion of the two members is engaged, and the engagement allows relative movement between the first engaging portion and the second engaging portion only in the longitudinal direction of the torsion bar, and A seismic isolation bearing configured so that the torsion bar is twisted by relative movement in the direction of. 2. The first member has a substantially cylindrical shape, and the plurality of torsion bars are provided on a side surface of the first member in a direction substantially tangential to the first member. Seismic isolation bearing described in 1. 3. The first member has a substantially cylindrical shape, and the plurality of torsion bars are provided on a side surface of the first member in a substantially radial direction of the first member. Seismic isolation bearing described in 1. 4. The first engaging portion is formed so as to extend from the free end of each torsion bar toward the second member side, and the second engaging portion is engaged with the first engaging portion. The seismic isolation bearing according to claim 1, wherein the seismic isolation bearing is formed of a long hole for fitting, and the long axis direction of the long hole is formed to coincide with the longitudinal direction of the torsion bar.