JPH09210129A - Seismic isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent base isolation device which is especially suitable for use in a cold district because of no dependency on temperature in comparison with that including rubber. SOLUTION: The base isolation device comprises an isolator element 1 including a receiving surface 2a of an upper halves having a concave section opposed vertically to a receiving surface 3a of a bottom halve having a concave section, and a flat rotating element 4 interposed between both receiving surface 2a and 3a, each supporting surface 4a and 4b thereof having convex section. The rotating element 4 is divided into an upper rotating member 40 forming the upper supporting surface 4a and lower rotating member 41 forming the lowering supporting surface 4b. And when interposing a rubber member 42 between the upper rotating member 40 and the lower rotating member 41, the upper rotating member 40 and the lower rotating member 41 are integrated so as to be movable in an elastic manner in the vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation device.

[0002]

2. Description of the Related Art As a conventional seismic isolation device, one using rubber is known. In this type of seismic isolation device, for example, it has a structure in which rubber and insert plates are alternately laminated between an upper plate and a lower plate, the lower plate is placed on the base, and the structure is placed on the upper plate. Used in support. According to this seismic isolation device, when an earthquake occurs while the load of the structure is vertically supported by the insert plate, the rubber is subjected to horizontal shear deformation to absorb energy.

However, in such a conventional seismic isolation device, since rubber is the main constituent element, the spring rigidity has a high temperature dependency and is stable when the temperature range in the operating environment is large. It has a technical problem that it is difficult to obtain the seismic isolation effect.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional technical problems, and has the following configuration. According to the invention of claim 1, the receiving surface 2a of the upper shoe 2 having the concave arc-shaped cross section and the receiving surface 3a of the lower shoe 3 having the concave arc-shaped cross section are arranged vertically so as to face each other, and the upper and lower support surfaces 4a and 4b each have a convex arcuate cross section and are provided with a seismic isolation element 1 for interposing a flat rotating member 4 between the receiving surfaces 2a and 3a. Therefore, it is obtained by the resultant force of the horizontal force H acting on the upper shoe 2 and the load V of the support member 11 supported by the upper shoe 2.
While the line of action of the normal force F generated between the receiving surface 2a of the rotating member 4 and the supporting surface 4a on the upper side of the rotating member 4 is directed downward from the rotation center O of the rotating member 4, the rotating member 4 has a predetermined angle range. A rotating seismic isolation device, wherein the rotating member 4 comprises an upper rotating member 40 forming an upper supporting surface 4a and a lower supporting surface 4a.
The upper rotary member 40 and the lower rotary member 41 are separated from each other in the vertical direction with the rubber member 42 interposed between the upper rotary member 40 and the lower rotary member 41. It is a seismic isolation device characterized by being integrated so as to be capable of elastic relative movement. According to a second aspect of the present invention, the upper rotary member 40 and the lower rotary member 41 are integrated by engaging a fitting groove 40a formed on one side with a plurality of protrusions 41a formed on the other side. The seismic isolation device according to claim 1. According to the invention of claim 3, the receiving surface 2a of the upper shoe 2 having the concave arc-shaped cross section and the receiving surface 3a of the lower shoe 3 having the concave arc-shaped cross section are arranged vertically so as to face each other, and the upper and lower support surfaces are arranged. 4a and 4b are provided with seismic isolation elements 1 for interposing a flat rotating member 4 having a convex arc-shaped cross section between both receiving surfaces 2a and 3a. Therefore, it is obtained by the resultant force of the horizontal force H acting on the upper shoe 2 and the load V of the support member 11 supported by the upper shoe 2, and the receiving surface 2a of the upper shoe 2 and the upper support of the rotating member 4 are supported. The line of action of the normal force F generated between the surface 4a and the surface 4a is the center of rotation (O) of the rotating member 4.
A seismic isolation device in which a rotating member 4 rotates in a predetermined angle range while pointing downwards, and a plurality of sliding members are provided on each of the receiving surface 2a of the upper shoe 2 and the receiving surface 3a of the lower shoe 3. 20 and 21 are arranged by embedding a part thereof, and the upper and lower support surfaces 4a and 4b of the rotating member 4 are slidable members 20 and 21, respectively.
It is a seismic isolation device that is in sliding contact with.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 11 show an embodiment in which a seismic isolation device according to the present invention is applied to a bridge. First, the outline of the seismic isolation element 1 will be described. Seismic isolation element 1
As shown in FIG. 7, it has an upper shoe 2, a lower shoe 3, and a rotating member 4 that rotates within a predetermined angle range. Kamitotsu 2 is the center O
Receiving surface 2a forming part of a concave spherical surface with radius R centered at ₁
There is formed, the lower shoe 3 is formed receiving surface 3a forming part of the concave spherical surface of radius R around the center O _2, also the rotating member 4, the upper and lower surfaces some of the convex spherical surface of radius R, respectively The support surfaces 4a and 4b forming the are formed to have a flat shape.

As shown in FIG. 8, the seismic isolation element 1 as described above is interposed between a foundation 10 which is a base and a bridge body 11 to be used for supporting the bridge. That is, the lower shoe 3 is fixed on the foundation 10 so that the receiving surface 3a faces upward, and the lower shoe 3 is fixed on the lower surface of the bridge body 11 so that the receiving surface 2a faces downward. Receiving surface 2a of shoe 2 and receiving surface 3 of lower shoe 3
They are arranged vertically so as to face a. And both receiving surfaces 2
The support surfaces 4a and 4b are received in the a and 3a, and the rotating member 4 is closely interposed. In this way, each bridge body 11
Each seismic isolation element 1 supported by a plurality of (four or more front, rear, left and right) seismic isolation elements 1 and interposed between the foundation 10 and the bridge body 11 constitutes a seismic isolation device.

A predetermined friction coefficient is given to the sliding surfaces between the receiving surface 2a of the upper shoe 2 and the receiving surface 3a of the lower shoe 3 and the respective support surfaces 4a and 4b of the rotating member 4. More specifically, as shown in FIGS. 1 and 6, a plurality of sliding members 20 and 21 are partially embedded in the receiving surfaces 2a and 3a, respectively. 4a and 4b are in sliding contact with the sliding members 20 and 21, respectively. Each of the sliding members 20 and 21 is formed of a resin having a low coefficient of friction, for example, a fluorocarbon resin (Teflon (registered trademark)) into a short tubular shape, and has a spherical receiving surface 2a, as shown in FIG. It is arranged on the center line of 3a and around the center line so as to be on the same circumference, and adjacent sliding members 20, 21 form a slight gap.

The sliding members 20 and 21 are mounted by cold fitting in consideration of usage conditions.
That is, by setting the cold fitting temperature of the sliding members 20 and 21 to be equal to or lower than the encounter temperature at the installation location of the seismic isolation device, the loosening of the sliding members 20 and 21 is favorably suppressed.
In addition, the sliding members 20 and 21 are the support surfaces 4 of the rotating member 4.
It is installed so as to occupy 40 to 50% of the area of the sliding surface between a and 4b, so that both stable support and smooth operation of the rotating member 4 are achieved. On the other hand, the supporting surfaces 4a, 4 of the rotating member 4
b is formed by top finishing and is plated with stainless steel or hard chrome if necessary. The contact surfaces of the sliding members 20 and 21 that come into contact with the support surfaces 4a and 4b of the rotary member 4 are adapted to the support surfaces 4a and 4b that are spherical surfaces.

As shown in FIG. 1, the rotary member 4 is divided into an upper rotary member 40 and a lower rotary member 41 which respectively form upper and lower support surfaces 4a and 4b.
0 and the lower rotary member 41 with a disc-shaped rubber member 42 interposed therebetween, the upper rotary member 40 and the lower rotary member 41
And are elastically integrated. That is, the upper rotary member 40 and the lower rotary member 41 have a plurality of protrusions 41a formed on one side in the annular fitting groove 40a formed on the other side.
Are engaged and integrated. Specifically, the fitting groove 4
0a is formed concentrically around the circular convex surface 40c at the center of the lower surface of the upper rotating member 40 as shown in FIGS. 2 and 3, and the protrusion 41a is the upper surface of the lower rotating member 41 as shown in FIGS. A short tubular portion 41d that defines a circular recess 41b in the central portion
A plurality (three) are formed on the outer diameter surface of the fitting groove 40a at predetermined intervals, and notches 40b corresponding to the protrusions 41a are formed at predetermined intervals in the circumferential direction of the fitting groove 40a.

As shown in FIG. 4, the rotary member 4 has a rubber member 42 inserted into the circular recess 41b of the lower rotary member 41, and the protrusions 41a are inserted from the notches 40b. 42 is the circular convex surface 4 of the upper rotary member 40
The upper and lower rotating members 40, 41 are appropriately elastically pressed by 0c so that the protrusions 41a are engaged with and integrated with the fitting groove 40a. is there. In the state where the rotary member 4 is integrated, the inner peripheral wall 40d of the fitting groove 40a is vertically slidably fitted to the outer peripheral wall 41c of the circular recess 41b of the lower rotary member 41 as shown in FIG. In addition, the protrusion 41a fits into the groove 4
The rubber member 42 is initially compressed by being locked to the lower wall 40e of the rubber member 0a. Further, in the state in which the rotary member 4 is integrated, as shown in FIG. 11, the short tubular portion 41d and each protrusion 4 are formed.
A slight gap is formed above 1a, and the upper rotation member 40
Further, the rubber member 42 is allowed to elastically compress and downward relative movement is allowed, which allows elastic upper and lower relative movement between the upper rotary member 40 and the lower rotary member 41. The rubber member 42 is made of vibration-proof rubber or natural rubber.

Further, as shown in FIG. 1, the space between the upper shoe 2 and the lower shoe 3 is covered with annular first and second seal rings 50 and 51 to prevent dust. First seal ring 50
Has an upper end fixed to the lower surface of the upper shoe 2, and a lower end fixed to the annular peripheral surface of the lower shoe 3. The second seal ring 51 has an upper end fixed to the annular outer peripheral surface of the upper shoe 2, and an annular support member 53 fixed to the upper surface of the outer peripheral portion of the lower shoe 3.
The lower end is fixed to the outer peripheral surface of the upper end of the. Note that 54
Are bolts for fixing the lower shoe 3 to the foundation 10.

Next, the operation will be described. When the horizontal force H'from the earthquake acts on the lower shoe 3 via the foundation 10 in the leftward direction in FIG. 7, the horizontal force H acts on the upper shoe 2 in the rightward direction, and the upper shoe 2 moves downward. Relative movement to the right with respect to the shoes 3 is started. The relative movement of the upper shoe 2 is continuously performed while the rotating member 4 is rotated in a predetermined angle range in the counterclockwise direction. As shown in FIG. 9, when the upper shoe 2 horizontally moves by the length U (maximum length), the center O ₁ becomes the center O _1.
Moved to ₁ ', the upper shoe 2 rises by δ from its original vertical position. δ is given by Equation 1 as the rising length of the center O ₁ .

[0013]

[Formula 1]

On the other hand, when the upper shoe 2 horizontally moves by the length U, the rotating member 4 moves in the counterclockwise direction by α = sin ^-1 (U /
L) and the center of rotation O is raised by δ / 2.
Here, L is the distance between the centers of curvature of the receiving surfaces 2a, 3a of the upper shoe 2 and the lower shoe 3, that is, the distance between the centers O _{1 and} O ₂ .

Now, ignoring the friction between the upper shoe 2 and the lower shoe 3 and the rotating member 4, the upper shoe 2 on which the load V of the bridge body 11 acts downward is moved to the right from the neutral position shown in FIG. When it is moved by the length U, the force is transmitted via the rotating member 4 on both receiving surfaces 2a, 3a. This force is transmitted by matching the radius R of the receiving surface 2a of the upper shoe 2 and the radius R of the upper supporting surface 4a of the rotating member 4 with the radius R of the receiving surface 3a of the lower shoe 3 and the lower portion of the rotating member 4. Since the radius R of the support surface 4b on the side is matched, the left half of the receiving surface 2a of the upper shoe 2 and the lower shoe 3
And the right half of the receiving surface 3a. Force F transmitted
Are opposite to each other in the normal direction of the curved receiving surfaces 2a and 3a, and the vertical component thereof is equal to the load V. Also,
The right horizontal component (horizontal force H) of the force transmitted when the upper shoe 2 moves rightward by the length U is the rotation angle α.
With reference to FIG.

[0016]

[Formula 2]

Considering the moment when the horizontal component (horizontal force H) of the normal force F (shown in FIG. 10) is loaded on the upper shoe 2 in the neutral position as shown in FIG. The counterclockwise rotation moment M of the rotating member 4 is given by
Then, the rotating member 4 starts to rotate.

[0018]

[Equation 3]

As shown in FIG. 9, the rotation of the rotating member 4 is such that the line of action of the normal force F passes through the rotation center O of the rotating member 4 at an angle α = sin ⁻¹ (U / L). It can be continued until. In this way, the line of action of the normal force F generated between the receiving surface 2a of the upper shoe 2 and the upper supporting surface 4a of the rotating member 4 is directed downward from the rotation center O of the rotating member 4. As long as transmission of force by normal force F occurs at
While the upper shoe 2 acting on the upper body moves upward together with the bridge body 11, the horizontal force H acting on the upper shoe 2 due to the earthquake, that is, the vibration is absorbed. Thus, the bridge body 11 and foundation 1
By constructing the seismic isolation device by interposing a plurality of seismic isolation elements 1 between the seismic isolation elements 1 and 0, the natural period of vibration originally possessed by the bridge is changed by the spring rigidity of the seismic isolation element 1. That is, the natural period of the bridge body 11 can be lengthened to prevent resonance and suppress the energy (impact force) transmitted to the bridge body 11 with an earthquake.

Although omitted in the above description, the frictional force existing between each receiving surface 2a, 3a and each supporting surface 4a, 4b actually acts as a resistance against the rotation of the rotating member 4. Due to this frictional force, energy is absorbed until the upper shoe 2 reaches the rising height δ, and rotation of the rotating member 4 in the clockwise direction is suppressed when the upper shoe 2 moves downward due to its own weight. Will be gradually dampened. Therefore, the friction between the receiving surfaces 2a and 3a and the supporting surfaces 4a and 4b of the rotating member 4 is preferably about 0.001 to 0.3. This static friction coefficient of about 0.001 to 0.3 is determined by the plurality of sliding members 20, 2
Given by 1.

Thus, the receiving surface 2a of the upper shoe 2 and the lower shoe 3
A plurality of sliding members 20, 21 on the receiving surface 3a of
Are arranged, the upper and lower support surfaces 4a and 4b of the rotating member 4 are arranged.
Are in sliding contact with the sliding members 20 and 21, respectively,
The smooth movement of the rotating member 4 is ensured, and the size is reduced as compared to the case where one large sliding member 20, 21 is arranged, and the influence of expansion and contraction deformation due to temperature is reduced to improve durability. Can be made. Further, since the adjacent sliding members 20 and 21 form a slight gap, the drainage of the condensed water is good from the drain hole 3b formed in the central portion of the lower shoe 3 as shown in FIG. Done

A receiving surface 2a of the upper shoe 2 and a receiving surface 3 of the lower shoe 3
In the state where a is closely engaged with each of the support surfaces 4a and 4b of the rotating member 4, the spring rigidity or the natural period of the seismic isolation element 1 is as shown in FIG.
The thickness t of the rotating member 4 shown in FIG. If the shape constant C = t / R, the range of C = 0.5 to 1.0 is preferable as the shape constant C for an earthquake.

Further, since the rotary member 4 is divided into the upper rotary member 40 and the lower rotary member 41, the workability is improved and the rotary member 4 is easily manufactured. Further, the rubber member 42 interposed between the integrated upper rotating member 40 and the lower rotating member 41 is received between the circular concave portion 41b and the circular convex surface 40c and is not easily deteriorated. The inner peripheral wall 40d of the engaging groove 40a is slidably fitted in the outer peripheral wall 41c of the circular recess 41b of the lower rotary member 41 in the vertical direction, so that shear deformation does not occur, and only in the vertical direction when receiving support pressure. Since the structure is subject to deformation, the temperature dependence is smaller than that in the case of being subjected to shear deformation. Therefore, the spring rigidity of the rubber member 42 changes due to the change of the ambient temperature, and if the natural period of the seismic isolation device changes due to this, no trouble occurs. In addition, while ensuring the above-described operation of the rotating member 4 during an earthquake, the rubber member 42 favorably absorbs the vertical impact force that acts on the rotating member 4 from the bridge body 11 during a non-earthquake.

It should be noted that the space between the upper shoe 2 and the lower shoe 3 is the first and the second.
Since it is covered with the seal rings 50 and 51 to prevent dust, it is possible to favorably prevent the smooth movement of the rotating member 4 from being obstructed by the dust over a long period of time.

By the way, although the bridge main body 11 is supported by the seismic isolation device in the above-mentioned one embodiment, it is possible to support not only the bridge but also various supporting members such as structures and mechanical devices. Of course there is. Further, the receiving surface 2a of the upper shoe 2 and the receiving surface 3a of the lower shoe 3 and the supporting surfaces 4a and 4b of the rotating member 4 are provided with spherical surfaces, but both receiving surfaces 2a,
3a is provided with a concave arc-shaped cross section, and the supporting surface 4a of the rotating member 4 is
It suffices if a convex arc-shaped cross section is given to 4b.
It is also possible to give a concave cylindrical surface to a and to give the support surfaces 4a and 4b of the rotating member 4 a convex cylindrical surface. As a result, the seismic isolation function cannot be exerted for all relative movements in the horizontal radial direction including the front-back direction like the spherical surface, but resonance is caused for the relative movements in the left-right direction in FIG. The seismic isolation function is suppressed.

[0026]

As will be understood from the above description,
According to the present invention, since it does not have temperature dependency as compared with the one using rubber, it is excellent as a seismic isolation device particularly suitable for cold regions. Further, according to the invention of claim 1, since the rotating member is divided and the rubber member supports the upper rotating member so as to be elastically movable in the vertical direction with respect to the lower rotating member, Not only is the manufacturing of the rotating member easier, but the impact force associated with the vertical movement during a non-earthquake is also buffered.

According to the third aspect of the invention, a plurality of sliding members are partially embedded in the receiving surface of the upper shoe and the receiving surface of the lower shoe, and the upper and lower support surfaces of the rotating member are arranged. Since the sliding members are in sliding contact with each other, durability of the sliding members can be ensured while giving a predetermined friction coefficient to the sliding surfaces between the sliding members and the respective supporting surfaces of the rotating member. As a result, smooth and stable movement of the seismic isolation device is ensured for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing a seismic isolation device according to a first embodiment of the present invention.

FIG. 2 is a half sectional view showing an upper rotary member of the same.

FIG. 3 is a bottom view showing a half part of the upper rotating member.

FIG. 4 is a half sectional view showing a lower rotating member of the same.

FIG. 5 is a plan view showing a half portion of the lower rotating member.

FIG. 6 is a view showing a sliding member for upper and lower shoes as well.

FIG. 7 is a schematic view showing a seismic isolation element.

FIG. 8 is a schematic view showing a bridge also provided with a seismic isolation device.

FIG. 9 is an explanatory view of the operation of the seismic isolation element.

FIG. 10 is an explanatory view of the action of the seismic isolation element.

FIG. 11 is a sectional view showing an essential part of the rotary member.

[Explanation of symbols]

1: seismic isolation element, 2: upper shoe, 2a: receiving surface, 3: lower shoe, 3
a: receiving surface, 4: rotating member, 4a, 4b: supporting surface, 1
0: foundation (base), 11: bridge body (support member), 2
0, 21: sliding member, 40: upper rotating member, 40a: fitting groove, 41: lower rotating member, 41a: protrusion, 42:
Rubber member, H: Horizontal force, V: Support member load, F:
Normal force, O: center of rotation of the rotating member.

Front page continuation (72) Inventor Shin Ono, 4 Chatsu-cho, Muroran-shi, Hokkaido Inside Japan Steel Works, Ltd. (72) Inventor Akihiko Atami 4 Chazu-cho, Muroran-shi, Hokkaido Inside Japan Steel Works, Ltd.

Claims (3)

[Claims] 1. A receiving surface (2a) having a concave arc-shaped cross section of an upper shoe (2) and a receiving surface (3a) having a concave arc-shaped cross section of a lower shoe (3) are arranged facing each other. Then, the seismic isolation element (where the upper and lower support surfaces (4a, 4b) each have a convex arc-shaped cross section and a flat rotating member (4) is interposed between the receiving surfaces (2a, 3a) ( 1), the rotation of the rotating member (4) causes the horizontal force (H) acting on the upper shoe (2) due to the earthquake and the load (11) of the support member (11) supported by the upper shoe (2). V) resulting from the resultant force between the receiving surface (2a) of the upper shoe (2) and the upper supporting surface (4a) of the rotating member (4), the acting line of the normal force (F) Is a seismic isolation device in which the rotating member (4) rotates within a predetermined angle range while pointing downward from the rotation center (O) of the rotating member (4), and the rotating member (4) The upper rotary member (40) forming the support surface (4a) and the lower rotary member (41) forming the lower support surface (4b) are divided into the upper rotary member (40) and the lower rotary member (41). Between the rubber member (4
A seismic isolation device characterized in that the upper rotary member (40) and the lower rotary member (41) are integrated so as to be capable of elastic relative movement in the vertical direction in a state in which 2) is interposed. 2. The upper rotating member (40) and the lower rotating member (41) are integrally formed by engaging a fitting groove (40a) formed on one side with a plurality of protrusions (41a) formed on the other side. The seismic isolation device according to claim 1, wherein the seismic isolation device is characterized. 3. A receiving surface (2a) having a concave arc-shaped cross section of the upper shoe (2) and a receiving surface (3a) having a concave arc-shaped cross section of the lower shoe (3) are arranged facing each other. Then, the seismic isolation element (where the upper and lower support surfaces (4a, 4b) each have a convex arc-shaped cross section and a flat rotating member (4) is interposed between the receiving surfaces (2a, 3a) ( 1), the rotation of the rotating member (4) causes the horizontal force (H) acting on the upper shoe (2) due to the earthquake and the load (11) of the support member (11) supported by the upper shoe (2). V) resulting from the resultant force between the receiving surface (2a) of the upper shoe (2) and the upper supporting surface (4a) of the rotating member (4), the acting line of the normal force (F) Is a seismic isolation device in which the rotating member (4) rotates within a predetermined angle range while pointing downward from the rotation center (O) of the rotating member (4), and the receiving surface (2a) of the upper shoe (2) is ) And the receiving surface (3a) of the lower shoe (3) respectively, a plurality of sliding members (20, 2).
1) is arranged by embedding a part thereof, and the upper and lower support surfaces (4a, 4b) of the rotating member (4) are respectively slidable members (20,
21) A seismic isolation device characterized by sliding contact with the seismic isolation device.