JP2015132303A - Lead-plug incorporated laminate rubber type base insulation bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead-plug incorporated laminate rubber type base insulation bearing having a durability improved by preventing the occurrences of cracks or ruptures due to the vibrations of minute amplitudes.SOLUTION: A lead-plug incorporated laminate rubber type base insulating bearing 10 includes: an elastic body 2 having elastic material layers and rigid material layers laminated alternately; and a columnar lead plug 1. The lead plug 1 is arranged in a cylindrical hollow part formed vertically in the elastic body 2, and the lead plug 1 is formed in at least its side face with a film part 11, to which a lubricant is applied.

Description

  The present invention relates to a laminated rubber type seismic isolation bearing with a lead plug used as a seismic isolation apparatus for a structure.

  Various devices having various materials, structures, and functions are used for the seismic isolation device for the structure, and this laminated rubber type seismic isolation bearing with a lead plug is one of them. In this laminated rubber type seismic isolation bearing with lead plugs, columnar lead plugs are arranged in hollow portions inside the laminated rubber bodies, and these lead plugs are restrained by upper and lower mounting steel plates and surrounding laminated rubber bodies. .

  Laminated rubber type seismic isolation bearings with lead plugs are installed in structures such as buildings and bridges, and are arranged between the lower structure and the upper structure on the foundation side of these structures. Generally, the compressive stress in the vertical direction acting on the seismic isolation bearing (the average stress in the vertical direction obtained by dividing the axial force acting on the seismic isolation bearing by the pressure-receiving area) is about 10 MPa or more. When used for a relatively lightweight structure such as a medium- or low-rise building, the compressive stress in the vertical direction may be 10 MPa. In addition, in the structure, when the base isolation is used at a place where the axial force is small, such as under the stairs or the lower house, the compressive stress in the vertical direction acting on the base isolation support may be less than 5 MPa. .

  And this laminated rubber type seismic isolation bearing with lead plug is capable of absorbing the energy received from earthquakes, etc. when the above laminated rubber body is greatly deformed in the horizontal direction and the lead plug disposed inside is deformed. (See Patent Document 1).

  In addition, in a seismic isolation device composed of an elastic-plastic material such as lead, mineral oil such as grease is used as a reinforcing paint on the surface of the seismic isolation damper as a means to suppress cracks and fractures due to metal fatigue. A maintenance method for a seismic isolation device that forms a coating film for reinforcement by coating and thereby suppresses the above-described cracks and breaks is disclosed by the inventors of the present invention (see Non-Patent Documents 1 and 2). ).

JP-A-9-105440

Keiko Morita, Ikuo Takayama, Ryo Yasunaga, “Study on fatigue properties of lead dampers for seismic isolation structures, fatigue suppression effect by surface coating”, Annual Meeting of the Architectural Institute of Japan B-2 Structure II, September 2012 Keiko Morita, Ikuo Takayama, Ryo Yasunaga, “Study on fatigue properties of lead dampers for seismic isolation structures, Part 2 On the effect of grease application on the suppression of metal fatigue”, Annual Meeting of the Architectural Institute of Japan B-2 Structure II, 2013 September

  By the way, the upper structure of the structure where the laminated rubber type seismic isolation bearing with lead plugs is installed has a structure for small and medium earthquakes, wind, traffic vibrations, ground microtremors, etc. in addition to large amplitude vibrations during earthquakes. The vibration of minute amplitude due to the response of the object is repeatedly generated. For this reason, for example, a member that is deformed by vibration, such as a lead plug of a laminated rubber type seismic isolation bearing with a lead plug disclosed in Patent Document 1, is repeatedly deformed by vibration of a minute amplitude during normal times.

  Like this lead plug, a member that absorbs vibration energy by deformation during an earthquake is formed of an elastic-plastic material such as lead. The members formed of these elastic-plastic materials are plastically deformed with respect to vibrations having a large amplitude during an earthquake and absorb vibration energy as described above. On the other hand, members formed of these elastic-plastic materials are elastically deformed to absorb vibration energy with respect to minute amplitude vibration.

  However, a member formed of an elastoplastic material such as lead is cracked due to metal fatigue on the surface when the vibration is repeated, and is broken when the vibration is repeated. When this member breaks, the seismic isolation device cannot absorb vibration energy and cannot exhibit predetermined seismic isolation performance during an earthquake.

  In fact, if a laminated rubber type base-isolated bearing with lead plugs is installed in a state where a strong compressive stress is applied in the vertical direction due to the load of the structure, the above-mentioned elastic-plastic material will not be deformed by the above-mentioned small amplitude deformation. No tensile stress acts on the metal, only the compressive stress always acts, and the repetition of the tensile / compressive stress does not occur. Therefore, the metal fatigue is unlikely to occur. However, as described above, laminated rubber type seismic isolation bearings with lead plugs may be used for relatively light structures such as steel structures and medium to low-rise buildings where the compressive stress in the vertical direction is less than 10 MPa. . In such a usage mode, since the compressive stress in the vertical direction due to the load of the structure is small, the tensile stress acts on the elastic-plastic material even during the minute vibration, and the tensile / compressive stress repeats, leading to lead. It becomes a state in which metal fatigue of the material is likely to occur.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lead plug-containing laminated rubber type seismic isolation bearing that has improved durability by preventing the occurrence of cracks and fractures due to minute amplitude vibrations.

  (1) An elastic body in which a plurality of elastic material layers and rigid material layers are alternately stacked, and a columnar lead plug are provided, and the lead plug is formed in the vertical direction inside the elastic body. A laminated rubber type seismic isolation bearing with a lead plug, which is disposed in a cylindrical hollow portion, and a coating portion formed by applying a lubricant is formed on at least a part of a side surface of the lead plug.

  Here, the lead forming the lead plug has an excellent performance as an energy absorbing member because of its excellent plastic deformation ability. In addition, lead has no stress amplitude limit point (fatigue limit) when it is repeatedly oscillated as compared with steel materials such as carbon steel, and therefore it is said that cracks are caused by metal fatigue even at low stress amplitude. In the case of laminated rubber type seismic isolation bearings with lead plugs, the lead plug made of lead plastically deforms and absorbs vibration energy for vibrations with large amplitudes such as those caused by earthquakes. It absorbs vibrational energy by elastically deforming vibrations of minute amplitude caused by the response of the structure to vibrations, microtremors of the ground, etc.

  According to the invention of (1), the surface of the lead plug caused by repetition of the above-mentioned vibration with the small amplitude is obtained by forming the coating portion by applying a lubricant to at least a part of the side surface of the lead plug. Generation of cracks due to metal fatigue can be prevented. Therefore, durability and reliability as a seismic isolation device of the laminated rubber type seismic isolation bearing with lead plug can be remarkably improved.

  (2) The lead-plug laminated rubber mold exemption according to (1), wherein a concavo-convex surface is formed on at least a part of a side surface of the lead plug, and the coating portion is formed on at least the concavo-convex surface. Seismic support.

  According to the invention of (2), the lubricant can be easily applied, and the lubricant can be prevented from flowing downward due to gravity, thereby improving the stability and fixability of the coating portion. In addition, the above-described effect of the invention of (1) can be more preferably expressed by increasing the surface area of the coating portion per unit area on the surface of the lead plug or the amount of coating per unit area.

  (3) The laminated rubber type seismic isolation bearing with a lead plug according to (1) or (2), wherein the lubricant is petrolatum.

  According to the invention of (3), by applying petrolatum to the surface of the lead plug, it is possible to more effectively prevent the occurrence of cracks and breaks due to minute amplitude vibration.

  (4) The laminated rubber type seismic isolation bearing with lead plug according to (1) or (2), wherein the grease is a grease having a mineral oil as a base oil.

  According to the invention of (4), by applying grease based on mineral oil to the surface of the lead plug, it is possible to more effectively prevent the occurrence of cracks and fractures due to minute amplitude vibrations. .

(5) The laminated rubber type seismic isolation bearing with lead plug according to (4), wherein the grease has a consistency number of 00 to 4.
Here, the “consistency number” in the present invention is a consistency number classified in JIS K2220, and indicates the external hardness of the grease. Consistency numbers No. 00 to No. 4 indicate that the state of appearance hardness at normal temperature is a range from soft to hard in a range from semi-fluid (concentration 000) to extremely hard (concentration 6). It is.

  According to the invention of (5), it is easy to apply the grease by forming the coating portion with grease having a consistency number of No. 00 to No. 4, and the grease flows downward due to gravity. Can be prevented.

  (6) A seismic isolation structure comprising the laminated rubber type seismic isolation bearing with lead plug according to any one of (1) to (5), wherein the laminated rubber type seismic isolation bearing with lead plug is the lead A seismic isolation structure arranged at a position where the compressive stress in the vertical direction acting on the laminated rubber type seismic isolation bearing with plug is 5 MPa or more and less than 10 MPa.

  Here, since seismic isolation devices such as seismic isolation bearings support the building load, generally a compressive stress in the vertical direction of about 10 MPa is always applied. Therefore, in this case, in the case of laminated rubber type seismic isolation bearings with lead plugs, there is actually little tensile stress acting on the lead plugs due to other minute vibrations during the earthquake. Metal fatigue of the plug is unlikely to occur.

  However, for example, when used in places where the compressive stress in the vertical direction is less than 10 MPa and relatively low in the compressive stress in the vertical direction, such as steel frames and medium to low-rise buildings, a laminated rubber mold with a lead plug is used. In the seismic isolation bearing, metal fatigue of the lead material due to the minute vibration is likely to occur.

  According to the invention of (6), even when used in places where the compressive stress in the vertical direction is less than 10 MPa and relatively low in the compressive stress in the vertical direction, such as steel structures and medium- and low-rise buildings. Since durability and reliability of the laminated rubber type seismic isolation bearing with lead plug can be sufficiently improved, a seismic isolation structure having excellent durability and reliability can be formed even in such a place.

  (7) A seismic isolation structure including the laminated rubber type seismic isolation bearing with lead plug according to any one of (1) to (5), wherein the laminated rubber type seismic isolation bearing with lead plug includes the lead plug. Seismic isolation structure arranged at a position where the compressive stress in the vertical direction acting on the laminated rubber type seismic isolation bearing is less than 5 MPa.

  According to the invention of (7), the compressive stress in the vertical direction of the structure, such as under the stairs and the lower house, is used in a small place, the compressive stress in the vertical direction is less than 5 MPa, The durability and reliability of laminated rubber-type seismic isolation bearings with lead plugs can be sufficiently improved even when they are used in places where the compressive stress is even smaller. A seismically isolated structure with excellent reliability and reliability can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated rubber type seismic isolation bearing with a lead plug which prevented generation | occurrence | production of the crack and fracture | rupture resulting from a vibration of minute amplitude, and improved durability can be provided.

It is a perspective view of a laminated rubber type seismic isolation bearing with a lead plug according to the present invention. It is a schematic diagram with which it uses for description of the internal structure of the laminated rubber type seismic isolation bearing with a lead plug which concerns on this invention. 1 is a perspective view of a preferred embodiment of a lead plug constituting a laminated rubber type seismic isolation bearing with a lead plug according to the present invention. It is a surface expansion schematic diagram with which it uses for description of the surface shape of the side surface of the lead plug of FIG.

  Hereinafter, although embodiment of this invention is described, this invention is not limited to this. In the description of the following embodiments, the same constituent elements are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  First, the whole structure of the laminated rubber type seismic isolation bearing 10 with a lead plug according to the present invention will be described with reference to FIG. 1 and FIG.

  The laminated rubber type seismic isolation bearing 10 with a lead plug is an example of a seismic isolation bearing, and is installed between a lower structure and an upper structure of the structure, and absorbs vibration energy. As shown in FIGS. 1 and 2, the laminated rubber type seismic isolation bearing 10 with lead plug includes an elastic body 2 in which a plurality of elastic material layers and rigid material layers are alternately laminated, a columnar lead plug 1, The lead plug 1 is disposed in a cylindrical hollow portion formed in the vertical direction inside the elastic body 2 in a manner that is constrained to the inner surface of the hollow portion without a gap. Further, the laminated rubber type seismic isolation bearing 10 with lead plugs has a lower flange 3 and an upper flange 4 which are in contact with the lower and upper surfaces of the lead plug 1 and are attached to the lower and upper surfaces of the elastic body 2 with bolts or the like, respectively. Prepare. For example, the lower flange 3 side is fixed to one structure such as a foundation, the other structure such as a building is placed on the upper flange 4 side, and a vertical load is applied from the building or the like via the upper flange 4. Installed and used to receive.

  In the laminated rubber type seismic isolation bearing 10 with the lead plug having such an overall configuration, it is necessary that the lead plug 1 disposed in the hollow portion of the elastic body 2 is constrained to the elastic body 2 without a gap. It is. However, on the other hand, when the elastic body 2 is restrained in such a manner that the lead plug 1 is excessively pressed, a problem may arise in the durability of the elastic body 2. Therefore, in the laminated rubber type seismic isolation bearing 10 with the lead plug, the lead plug 1 is arranged in a state where an appropriate pressure is applied from the inner peripheral surface of the hollow portion of the elastic body 2 to the side surface of the lead plug 1. It is preferable to do so.

  The lead plug 1 is made of lead having a purity of 99.99% or more as an elastic-plastic material. The lead plug 1 is preferably an annular body or a cylindrical body, but may have other shapes such as an ellipse or a rectangular body and an ellipse or a rectangular body. In addition, one lead plug 1 may be provided for the elastic body 2, but instead, a plurality of hollow portions are formed in one elastic body 2, and the lead plugs 1 are disposed in the plurality of hollow portions, respectively. And you may comprise the laminated rubber type seismic isolation bearing 10 containing a lead plug. The height of the lead plug 1 is generally about 300 mm to 600 mm, but can be set to any height depending on the required seismic isolation performance and the installation space of the structure. Further, the lead plug 1 can have any dimensions including the cross-sectional diameter and the balance with the size of the elastic body 2 according to the required seismic isolation performance and the installation space of the structure.

  Furthermore, as shown in FIG. 3, the lead plug 1 preferably has a concavo-convex surface 111 formed on at least a part or substantially the entire side surface thereof. By forming the uneven surface 111 on the side surface of the lead plug 1, it is easy to apply a lubricant, which will be described in detail later, and the lubricant is prevented from flowing downward due to gravity. Stability and fixability can be improved. Among the various seismic isolation devices, the laminated rubber type seismic isolation bearing with lead plugs is particularly suitable for use in a mode in which the lead surface, which is prone to metal fatigue due to micro vibrations, is not exposed to the outside and is stored in an elastic body. For this reason, when the lubricant is inserted into the elastic body after the application of the lubricant, if the stability of the coating portion is poor, the production stability is significantly lowered. Therefore, in the laminated rubber type seismic isolation bearing with lead plug, high stability of the coating is required from the manufacturing stage. In the laminated rubber type seismic isolation bearing 10 with a lead plug according to the present invention, an uneven surface 111 is formed on the side surface of the lead plug 1, and a lubricant is applied to the uneven surface 111 to thereby form such a coating portion. It can meet the demand for stability.

  Further, by forming the uneven surface 111 on the side surface of the lead plug 1, the surface area of the coating portion 11 per unit area on the surface of the lead plug 1 or the increase in the amount of lubricant applied per unit area can lead to the lead plug 1. The durability and reliability of the laminated laminated rubber type seismic isolation bearing 10 can be further improved.

  The elastic body 2 is a cylindrical or prismatic elastic body in which a plurality of elastic material layers made of an elastic material and a rigid material layer made of a rigid material are alternately laminated.

  Examples of the material of the elastic material layer include natural rubber, silicon rubber, high damping rubber, urethane rubber, chloroprene rubber, and the like, and natural rubber is preferable. The thickness of each layer of the elastic material layer is preferably about 1 mm to 30 mm in an unloaded state, but is not limited thereto.

  Examples of the material of the rigid material layer may include a fiber reinforced synthetic resin plate such as a steel plate, carbon fiber, glass fiber, or aramid fiber, or a fiber reinforced hard rubber plate, and the thickness thereof is 10 mm for each thick rigid plate. About 50 mm, and each other layer is preferably about 1 mm to 6 mm, but is not limited thereto, and the number of layers is not particularly limited. Also, for the lower flange 3 and the upper flange 4, a plate-like member made of a rigid material such as the above steel plate can be appropriately selected and used.

  The laminated rubber type seismic isolation bearing 10 with lead plug of the present invention further has a coating 11 formed on at least a part, preferably substantially all, of the side surface of the lead plug 1. As a specific example of the coating part 11, what is formed by apply | coating petrolatum with the thickness of 160 micrometers in the surface of the side surface of the lead plug 1 can be mentioned. In this case, as petrolatum, any white petrolatum manufactured by Kenei Pharmaceutical Co., Ltd. can be used as long as it is a chemical called petrolatum. When the uneven surface 111 is formed on a part of the lead plug 1, the coating portion 11 is particularly formed at least in a portion including the uneven surface 111. The coating portion 11 is formed by applying petrolatum to the side surface of the lead plug 1 after warming petrolatum from 38 ° C. to 60 ° C.

Further, as another specific example of the coating part 11 of the laminated rubber type seismic isolation bearing 10 with the lead plug of the present invention, the coating part 11 is coated with grease based on mineral oil on the side surface of the lead plug 1. What is formed by doing can be mentioned as a more preferable specific example. In this case, the coating portion 11 is preferably formed by applying grease (for example, lithium composite soap grease) at a thickness of 80 g / m ² . In this embodiment, the lithium composite soap base grease is used as the grease. However, any grease such as calcium soap base grease, aluminum complex soap base grease, lithium complex soap base grease may be used as long as the grease is based on mineral oil. The grease can be used. As the grease, greases whose consistency numbers classified in JIS K2220 are included in No. 00 to No. 4 can be used.

  Each of the lubricants described above is formed by applying to the surface of the lead plug 1 with a brush or a roller. Alternatively, the grease or the like may be diluted and sprayed on the side surface of the lead plug 1 by spraying or the like.

  As described above, the laminated rubber type seismic isolation bearing 10 with the lead plug is provided with the coating portion 11, so that the lead plug 1 that absorbs the vibration energy by being deformed is cracked or broken due to the vibration of the minute amplitude. Can be prevented.

  It has already been confirmed by the present inventors that metal fatigue of a member made of lead can be suppressed by forming a coating portion with grease or the like, and the result has already been disclosed in Non-Patent Documents 1 and 2. That's right. However, application of this to a laminated rubber type seismic isolation bearing with lead plugs, which is a seismic isolation device that is relatively easy to reduce in size according to the location, is a completely new seismic isolation structure that has been overlooked by those skilled in the art. It is the composition. That is, by allowing the laminated rubber type seismic isolation bearing 10 with lead plug of the present invention to be placed in a relatively low vertical compressive stress as described above while maintaining its durability, The fact that it is possible to form a seismic isolation structure that is extremely excellent in durability, reliability, and economic efficiency is an advantageous effect unique to the present invention that is difficult even for those skilled in the art.

  Furthermore, in view of the configuration in which the lead plug 1 is restrained by the elastic body 2, an uneven surface 111 is formed on the side surface of the lead plug 1 in order to improve the workability when forming the coating portion 11 and the stability of the formed coating portion 11. By providing the above, the above-described effect is more remarkably and surely expressed.

DESCRIPTION OF SYMBOLS 1 Lead plug 11 Coating part 111 Uneven surface 2 Elastic body 3 Lower flange 4 Upper flange 10 Laminated rubber type seismic isolation bearing with lead plug

Claims (7)

An elastic body in which a plurality of elastic material layers and rigid material layers are alternately laminated;
A columnar lead plug; and
The lead plug is disposed in a cylindrical hollow portion formed in the vertical direction inside the elastic body,
A laminated rubber type seismic isolation bearing with a lead plug in which a coating portion formed by applying a lubricant is formed on at least a part of a side surface of the lead plug.   The laminated rubber type seismic isolation bearing with lead plug according to claim 1, wherein an uneven surface is formed on at least a part of a side surface of the lead plug, and the coating portion is formed on at least the uneven surface.   The laminated rubber type seismic isolation bearing with a lead plug according to claim 1 or 2, wherein the lubricant is grease or petroleum jelly.   The laminated rubber type seismic isolation bearing with a lead plug according to claim 3, wherein the grease is a grease based on mineral oil.   The laminated rubber type seismic isolation bearing with lead plug according to claim 4, wherein the grease has a consistency number of No. 00 to No. 4. A base-isolated structure comprising the laminated rubber type base-isolated bearing with a lead plug according to any one of claims 1 to 5,
The lead-plug laminated rubber type seismic isolation bearing is a seismic isolation structure arranged at a position where the compressive stress in the vertical direction acting on the lead plug-containing laminated rubber type seismic isolation bearing is 5 MPa or more and less than 10 MPa. A base-isolated structure including the laminated rubber type base-isolated bearing with a lead plug according to any one of claims 1 to 5,
The lead-plug laminated rubber type seismic isolation bearing is a seismic isolation structure arranged at a position where the compressive stress in the vertical direction acting on the lead plug-containing laminated rubber type seismic isolation bearing is less than 5 MPa.

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