JP2002250394A - Base isolation device using slide bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To respond to various kinds of vibration from a minute vibration level to a large vibration level in a large earthquake by a pair of devices. SOLUTION: A base isolation device using a slide bearing comprises: a slide plate 10 fixed to one of upper and lower structures 1, 3; and a slide member 4 fixed to the other upper or lower structure 1 and slidably arranged to the slide plate 10. In this base isolation device using a slide bearing, the slide plate 10 is formed such that a coefficient of friction in a slide surface 12 in the outer peripheral part of the slide member is made smaller than a coefficient of friction in a slide surface 13 which is in the further peripheral part than the outer peripheral part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member having a sliding member and a sliding member provided slidably with respect to the sliding member, and having a seismic isolation function interposed between upper and lower structures. It is related to seismic isolation device by bearing.

[0002]

2. Description of the Related Art In recent years, in order to ensure the safety of a structure against earthquakes, seismic isolation devices are interposed between the foundations of the structures and pillars on the middle floors, etc. Various seismic isolation structures have been developed to attenuate the vibrations that propagate to the structure and reduce the stress and deformation generated in the frame of the structure. Seismic isolation devices used for such structures are roughly classified into those using elastic bearings using laminated rubber or the like and those using sliding bearings or rolling bearings.

Here, the seismic isolation device using the above-mentioned sliding bearing is as follows.
As shown in FIG. 2, a flat sliding plate 2 made of stainless steel or the like mounted on a lower structure 1 such as a foundation, and fixed to the lower surface of an upper structure 3 and slidably mounted on the sliding plate 2. And a sliding material 4 made of a material such as Teflon (registered trademark). The vertical load from the upper structure 3 cooperates with the height adjusting steel pipe 5 in normal times. In addition to the bearing, when the lower structure 1 is horizontally displaced during an earthquake, the sliding member 4 slides on the sliding plate 2, and the frictional force generated at the time of the sliding causes the horizontal structure to act on the upper structure 3. The force is attenuated to ensure the soundness of the upper structure 3.

[0004]

In the above-described seismic isolator using the conventional sliding bearing, the friction coefficient of the sliding surface 2a of the sliding plate 2 on which the sliding member 4 slides becomes substantially uniform over the entire surface. Sliding material 4 for sliding plate 2
Is performed smoothly, and as a result, sufficient seismic isolation performance can be achieved. Therefore, the friction coefficient of the sliding surface 2a is usually set to a small value of 0.1 or less.

However, if the coefficient of friction of the sliding surface 2a is set to be small, there is a problem that the sliding member 4 slides even on a minute level of vibration due to a strong wind or the like. For this reason, when it is not desired to cause sliding of the sliding member 4, that is, displacement movement of the upper structure 3, or to suppress the maximum amplitude of the sliding member 4 at the time of a large earthquake in response to this kind of minute level vibration. In this case, it is necessary to set a large coefficient of friction on the sliding surface 2a.

However, when the coefficient of friction of the sliding surface 2a of the sliding plate 2 is increased, the sliding property of the sliding member 4 is reduced, so that a sufficient seismic isolation effect cannot be exerted, and vibrations are reduced. There is a contradictory problem that the residual displacement of the sliding member 4 after completion is increased.

Therefore, in order to solve the above problems, for example, in order to return the structure to the vicinity of the original position after the earthquake,
Measures such as installing a restoring device such as a horizontal spring separately, or installing a seismic isolation device using the sliding bearing and a seismic isolation device using laminated rubber bearings in parallel have been adopted. The measure for installing the restoration device has a problem that the number of components increases, the construction becomes complicated, and the installation work requires a lot of time and labor and increases the cost.

When a seismic isolation device for a laminated rubber bearing and a seismic isolation device for a sliding bearing are combined, the seismic isolation device for a sliding bearing or a laminated rubber bearing is individually provided for each foundation or column. Because it is interposed, it is difficult to apply it to a structure with a small site area, and even when it is applied to a structure with a large site area, the difference in the amount of settlement due to the difference in vertical rigidity There is a possibility that uneven settlement may occur, and as a result, it is necessary to devise the arrangement of the seismic isolation device for the sliding bearing and the laminated rubber bearing, and thus there is a problem that the design restriction is increased.

The present invention has been made in view of such circumstances, and a set of devices can cope with various vibrations from a minute vibration level to a large vibration level during a large earthquake. It is intended to provide a seismic isolation device using a sliding bearing.

[0010]

According to a first aspect of the present invention, there is provided a seismic isolation device using a sliding bearing according to the present invention, wherein the sliding plate is fixed to one of the upper and lower structures and the sliding plate is fixed to the other. In a seismic isolation device using a sliding bearing having a sliding member slidably provided, a friction coefficient at an outer peripheral portion of the sliding member is changed by a friction coefficient at a further peripheral portion of the outer peripheral portion of the sliding member. It is characterized in that it is formed to be smaller than that.

According to a second aspect of the present invention, in the seismic isolator according to the first aspect, the sliding surface of the sliding plate has a coefficient of friction at an original position of the sliding material.
It is characterized in that it is formed so as to be larger than the friction coefficient at the outer peripheral portion and smaller than the friction coefficient at the peripheral portion.

Here, the above configuration will be described in more detail. The sliding surface of the sliding plate is concentrically partitioned, and the friction coefficient at the original position of the sliding material located at the center is 0.1 to 0.1.
It is preferable that the friction coefficient at the outer peripheral portion of the sliding material located on the outer peripheral side is set to less than 0.1, and the friction coefficient at the peripheral portion is set to 0.2 or more.

According to the seismic isolation device using the sliding bearing according to the first or second aspect, the sliding property of the sliding material is improved by setting the friction coefficient of the sliding surface located on the outer peripheral portion of the sliding material to be small. A sufficient seismic isolation effect is obtained, and the residual displacement is suppressed. In addition, since the coefficient of friction of the sliding surface in the peripheral portion of the outer peripheral portion is set to be larger than that of the outer peripheral portion, when the sliding amplitude of the sliding material increases due to a large earthquake, the above-described peripheral portion has Excessive amplitude is suppressed.

In particular, in the seismic isolation device according to the second aspect, the friction coefficient of the sliding surface at the original position of the sliding material is set to be larger than the friction coefficient of the outer peripheral portion. As a result, against a minute level of vibration that the seismic isolation device does not want to act on, the sliding surface at the original position of the sliding material having a large friction coefficient has a locking function, so that the seismic isolation effect can be suppressed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a seismic isolation device using a sliding bearing according to the present invention, and other components are the same as those shown in FIG. In the following, the same reference numerals are given and their illustration is omitted. In FIG. 1, reference numeral 10 denotes a sliding member made of stainless steel or the like fixed to the lower structure 1, and the sliding member 4 is slidably provided on sliding surfaces 11 to 13 of the sliding plate 10. I have.

In this embodiment, the sliding plate 1
0 is concentrically sectioned into three portions having different friction coefficients, and the friction coefficient of the sliding surface 11 at the original position of the sliding material 4 at the center is within the range of 0.1 to 0.2. The coefficient of friction of the sliding surface 12 at the outer peripheral portion of the sliding material 14 is 0.1
And the friction coefficient of the sliding surface 13 in the peripheral portion located on the outer peripheral side of the sliding surface 12 is formed to be 0.2 or more. As a result, the friction coefficient of the sliding surface 11 is set to be larger than the friction coefficient of the sliding surface 12 and smaller than the friction coefficient of the sliding surface 13.

As a method of forming the sliding surfaces 11 to 13 with different friction coefficients from each other, for example,
A method of changing the surface roughness of 0 or performing a different surface treatment on each of the sliding surfaces 11 to 13 so as to be on the same plane is applicable. Further, the sliding surfaces 10 to 11 can be formed without forming the entire sliding plate 10 with the same metal material such as stainless steel.
The sections corresponding to 13 may be made of materials having different friction coefficients from each other.

According to the seismic isolation device using the sliding bearing having the above configuration, the sliding surface 1 located on the outer peripheral portion of the sliding member 10 is provided.
By setting the friction coefficient of No. 2 to a small value, the slidability of the sliding member 4 can be enhanced, a sufficient seismic isolation effect can be obtained, and the residual displacement can be suppressed. In addition, since the coefficient of friction of the sliding surface 13 in the peripheral portion of the outer peripheral portion is set to be larger than that of the sliding surface 12, when the sliding amplitude of the sliding material 4 increases due to a large earthquake, Excessive amplitude can be suppressed.

In addition, since the friction coefficient of the sliding surface 11 at the original position of the sliding material 4 is set to be larger than the friction coefficient of the sliding surface 12 in the outer peripheral portion, it is desired to operate the seismic isolation device in a strong wind or the like. With respect to vibration of a minute level that is not present, the sliding surface 11 having a large coefficient of friction exerts a locking function, so that seismic isolation can be suppressed. As a result, according to the seismic isolation device, various vibrations from a minute vibration level to a large vibration level at the time of a large earthquake can be handled by only one set.

In the above embodiment, the sliding plate 10 has a rectangular shape in plan view. However, the present invention is not limited to this. The same applies to various shapes such as a circular shape in plan view. Applicable to Further, the seismic isolation device using the sliding bearing according to the present invention fixes the sliding plate to the upper structure,
Even when the sliding material is fixed to the substructure and used,
A similar effect can be obtained.

Furthermore, in the above-described embodiment, only the case where the sliding plate 10 is concentrically partitioned into three portions having different friction coefficients has been described, but the present invention is not limited to this. May be formed so that one coefficient of friction gradually changes to the other coefficient of friction.

[0022]

As described above, claim 1 or claim 2
According to the seismic isolation device using the sliding bearing described in (1), a sufficient seismic isolation effect can be obtained in the outer peripheral portion of the sliding material, and the residual displacement can be suppressed. Can be suppressed from becoming excessive. In particular, according to the seismic isolation device of the second aspect, it is possible to suppress the seismic isolation effect for a minute level of vibration at the original position of the sliding member. As a result, a single set of devices can cope with various vibrations from a minute vibration level to a large vibration level during a large earthquake.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sliding plate in an embodiment of a seismic isolation device using a sliding bearing according to the present invention.

FIG. 2 is a front view showing an installed state of a seismic isolation device using a general sliding bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower structure 3 Upper structure 4 Sliding material 10 Sliding plate 11 Sliding surface in the original position of sliding material 12 Sliding surface in the outer peripheral part of sliding material 13 Sliding surface in peripheral part

Claims (2)

[Claims] 1. A seismic isolation device with a sliding bearing comprising a sliding plate fixed to one of upper and lower structures and a sliding member fixed to the other and slidably disposed with respect to the sliding plate. A sliding surface of the sliding plate is formed such that a friction coefficient at an outer peripheral portion of the sliding material is smaller than a friction coefficient at a further peripheral portion of the outer peripheral portion. 2. The sliding surface of the sliding plate is formed such that a friction coefficient at an original position of the sliding member is larger than a friction coefficient at the outer peripheral portion and smaller than a friction coefficient at the peripheral portion. Claim 1 characterized by the following:
The seismic isolation device using the sliding bearing described in.