JP6132224B2 - Seismic isolation method and base - Google Patents

Description

  The present invention relates to a seismic isolation method and a seismic isolation table for avoiding or reducing the collapse, damage, and fall of articles inside and outside a building, such as furniture, equipment, and products on a shelf, when an earthquake occurs.

  The earthquake not only causes the building itself to collapse or break, but even if the building does not collapse, furniture, fixtures, ornaments, etc. inside or around the building, such as machinery, equipment, It is often seen that fixtures, stores, etc. are shelves, and the products on the shelves (herein, these are collectively referred to as “furniture etc.”) collapse or damage. The countermeasures to these that have been taken in the past have been to physically fix the target furniture and the like. Examples include fixing the shelves to the wall, installing a collapse prevention bar between the ceiling, and fixing the equipment to the floor. However, since the seismic force is composed of a waveform having an undetermined period, acceleration, velocity, and displacement, these fall prevention measures are not always perfect for such a seismic force. Moreover, even if a merchandise shelf can be fixed in a store or the like, it does not prevent the merchandise placed on the shelf from falling.

  As a measure to avoid damage caused by earthquakes, the building itself is made to be earthquake-resistant structure, seismic control structure, seismic isolation structure. However, these technologies can only be applied at the time of new construction of a building and are generally not possible to be retrofitted. On the other hand, to prevent damage to furniture, etc., apart from buildings, in addition to the above-mentioned physical fall prevention measures, technology to prevent vibrations associated with earthquakes from being transmitted directly to furniture, etc. In other words, a device for absorbing the shaking of an earthquake interposed between a floor surface and furniture is also disclosed in the prior art. As specific examples, a device that absorbs the vibration of the floor using a laminated rubber body (see, for example, Patent Document 1), and a device that maintains furniture in a non-contact state using a magnetic floating mechanism (for example, a patent) Reference 2), a device that floats and supports furniture and the like using an air spring (see, for example, Patent Document 3), and a device that slides furniture and the like by using a roller rolling (see, for example, Patent Document 4). Etc. are seen. These are called seismic isolation devices, seismic isolation tables, or vibration isolation devices, vibration isolation tables. In this specification, these are collectively referred to as a “base isolation table”.

JP 2011-099544 A JP 2010-223284 A JP 2010-203594 A JP 2008-309206 A JP 2011-47514 A

  All of the conventional base isolation tables as described in the above prior art documents have complicated and large structures. Although it can be applied to relatively large mechanical devices, it has been difficult to apply to merchandise shelves in stores, furniture in the home, and the like. Therefore, unlike the prior art, the present invention has a simple structure, is easy to install and is advantageous in terms of cost, and can be easily applied from large equipment to household shelves, desks, etc. The purpose is to provide a seismic isolation table with a simple structure.

  In the present invention, a sliding member, that is, a sliding member is interposed between the floor surface and furniture, etc., and the above problem is solved by absorbing the shaking by relative sliding (sliding) between the two. Specifically, the following contents are included. In the prior art, a device using a sliding action has been disclosed (for example, see Patent Document 5). However, according to this, not only a sliding member but also a movable member, a movable support member, and a restoration member are disclosed. It was still difficult to handle because of its complicated structure. The present invention provides a sliding base isolation table having a simpler structure and a base isolation method.

  One aspect of the present invention is a seismic isolation method for protecting furniture or the like arranged in or around a building from collapse or damage in the event of an earthquake, and comprising a sliding sheet made of a low friction material and the slide A pair of sliding members composed of cushion sheets that are overlaid so as to back up a moving sheet are overlapped so that the sliding sheet surfaces of both of the sliding members face each other, the floor surface of the building, the furniture, etc. To reduce vibration caused by an earthquake transmitted from the floor surface to the furniture or the like by a sliding action between the pair of opposed sliding sheets and / or a damping action of the cushion sheet. The seismic isolation method is characterized by

  The pair of sliding members are overlapped and arranged between the floor surface of the building and the furniture, or the plurality of the sliding members are individually arranged between the floor surface of the building and the furniture, etc. You may make it reduce a vibration.

  By connecting at least a part of the periphery of the pair of sliding members, or by tying them with an elastic connecting member, the relative displacement amount between the pair of sliding members is limited or the pair of relative movement is performed. The sliding member can be configured to return to the origin. Further, by attaching a vibration absorbing member to at least one of the pair of sliding members, the vibration in the vertical direction due to the earthquake can be further absorbed.

  Another aspect of the present invention is a seismic isolation table disposed between a floor of a building and the furniture in order to protect the furniture disposed in or around the building from collapse or damage in the event of an earthquake. It is composed of a pair of sliding members composed of a sliding sheet made of a low friction material and a cushion sheet overlaid to back up the sliding sheet, and the surfaces of the sliding sheets of the pair of sliding members are The seismic isolation table is configured to reduce vibration caused by an earthquake by sliding action between the sliding sheets and / or damping action of the cushion sheet.

  Around the sliding member arranged on the floor surface side of the pair of sliding members, the movement allowance for the relative movement of both sliding members is compared with the sliding member arranged on the furniture side. Extra can be provided. The sliding member disposed on the floor surface side is disposed in the frame body, and a cushioning material that cushions the movement of the sliding member disposed on the furniture or the like side relative to the frame body is provided on the movement allowance. It may be provided.

  A releasable restraining mechanism for accepting or restraining relative movement between the pair of sliding members may be further provided.

  A vibration absorbing member that further absorbs vibration in the vertical direction due to an earthquake can be attached to at least one of the pair of sliding members.

  The at least part of the periphery of the pair of sliding members or the entire periphery is joined, or at least part of the periphery of the pair of sliding members is connected by an elastic coupling member, and the relative displacement amount of the pair of sliding members The relative movement between the pair of sliding members can be returned to the origin.

  By implementing the base isolation table according to the present invention, it is possible to provide a base isolation base and a base isolation method that are much simpler and less expensive than the prior art, and that are easy to install, handle, and manage. In addition, by stacking two or three base isolation bases composed of a pair of sliding members, and a multi-layer base isolation base structure, it is possible to take a large relative movement amount even in an earthquake with a large impact energy, It is possible to add a function to relieve shock and also have an origin return mechanism.

It is a front fragmentary sectional view which shows the base isolation table which concerns on embodiment of this invention. It is a perspective partial cross section which shows the base isolation table which concerns on other embodiment of this invention. It is a perspective fragmentary sectional view which shows the other aspect of the base isolation table shown in FIG. It is a perspective view which shows the seismic isolation table which concerns on other embodiment of this invention. It is a perspective view which shows the seismic isolation table which concerns on other embodiment of this invention. It is a perspective view which shows the other aspect of the base isolation table shown in FIG.

  A base isolation table according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a base isolation table 10 according to the present embodiment, and FIG. 1 shows the base isolation table 10 in a cross section perpendicular to the floor surface. In FIG. 1, the base isolation table 10 includes a first cushion sheet 11 laid on the floor 50 and a first and second pair of low friction materials laid on the first cushion sheet 11. 2 sliding sheets 12 and 13 and a second cushion sheet 14 further laid on both sliding sheets 12 and 13. FIG. 1 shows an example applied to a general house. The floor 50 is a timber floor, a carpet 51 is laid on the base isolation table 10, and a television 52 is placed thereon as an example. A TV stand 53 is mounted. In the drawing, for the sake of convenience, a space is provided between the first and second sliding sheets 12 and 13 constituting the base isolation table 10, but this is for ease of explanation. These are superposed so as to be in close contact with each other. The same applies to each embodiment described below.

  The first cushion sheet 11 is laid so as to be in contact with the floor surface directly or indirectly (for example, via mats or the like), thereby absorbing the unevenness of the floor surface with the flexibility of the cushion sheet 11. Therefore, the cushion sheet 11 is preferably made of a flexible material that is in close contact with the uneven floor surface. In the present embodiment, a rubber waterproof sheet having a thickness of 1.5 mm is used. In addition to the above, other materials that can absorb unevenness on the floor surface, such as asphalt sheets, rubber sheets, rubber mats (ballast mats), and plastic sheets, may be used. The thickness of the cushion sheet 11 may be a necessary and sufficient thickness that can absorb unevenness of the floor surface and does not cause a sense of incongruity during use, and 1.5 mm is merely an example. Due to the action of the cushion sheet 11, the unevenness of the floor surface is absorbed and plays a role of reducing friction between the sliding sheets 12 and 13 described later. In addition, when the floor is made of concrete in a factory or a warehouse, use of a cushion sheet made of a material having alkali resistance increases the durability. In this case, it also serves to prevent moisture from entering from the concrete floor.

  Next, a pair of a first sliding sheet 12 that constitutes a sliding surface on the first cushion sheet 11 and a second sliding sheet 13 that also constitutes a sliding surface on the first cushion sheet 11. Will be laid. At the time of laying, the first sliding sheet 12 positioned on the lower side may be adhered or welded and fixed to the first cushion sheet 11 partially or entirely using an adhesive or an adhesive. The second sliding sheet 13 on the second sliding sheet 13 is slidable with the first sliding sheet 12. The shaking of the earthquake is absorbed between the first and second sliding sheets 12 and 13. For this reason, it is preferable that the static friction coefficient between both the sliding sheets 12 and 13 is as low as possible. In the present embodiment, both sliding sheets 12 and 13 use a fluororesin sheet having a thickness of 0.075 mm. The static friction coefficient between both the sliding sheets 12 and 13 by this can be stored in about 0.2 so that it may mention later.

  As fluororesin materials constituting the fluororesin sheet, tetrafluoroethylene (PTFE), fluorinated ethylene polypropylene copolymer (FEP), tetrafluoroethylene-ethylene polymer (ETFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene- Examples include, but are not limited to, perfluoroalkyl vinyl ether copolymer (PFA).

  As shown in the following [Table 1], according to the experiments of the present inventors, the combination of the fluororesin sheets shows the lowest friction coefficient as the material of the sliding sheet, but as other materials, Use of an ultra high molecular weight polyethylene sheet (preferably having a molecular weight of 1 million or more) is also conceivable. When the pair of sliding sheets is a combination of a fluororesin sheet and an ultra-high molecular weight polyethylene sheet, the friction coefficient between them is about 0.25. If this is a combination of ultra-high molecular weight polyethylene sheets, the friction coefficient decreases to about 0.4. In the future, when a sheet material having a low friction coefficient is newly developed, application to the present invention is easily assumed, and the present invention does not exclude application of these materials. In the present specification, the coefficient of static friction between the sliding sheets is preferably about 0.4 or less.

  Next, the second cushion sheet 14 is laid on the second sliding sheet 13. Similar to the first cushion sheet 11, the second cushion sheet 14 has the flexibility to absorb unevenness on a plane such as furniture that will be placed on the cushion sheet 11 later. In the present embodiment, the same rubber sheet as the first cushion sheet 11 is used and the plate thickness is set to 1.5 mm, but this is merely an example. When the second cushion sheet 14 is laid on the second sliding sheet 13, the two cushion sheets 14 may be adhered or fixed partially or entirely using an adhesive material or an adhesive material. As a result, the first and second sliding sheets 12 and 13 have a sandwich structure sandwiched between the first and second cushion sheets 11 and 14 that back them up. The first and second cushion sheets 11 and 14 have a damping action due to the characteristics of the material, and this also has the effect of absorbing the vibration in the vertical direction during an earthquake. In this specification, a combination of a sliding sheet and a cushion sheet is referred to as a “sliding member”. A pair of sliding members form the base isolation table 10 by overlapping the surfaces of the sliding sheets of the sliding members facing each other.

  The carpet 51 placed on the base isolation table 10 is arbitrary. However, it is preferable to use the carpet 51 in order to prevent dust from entering the gap between the sliding sheets 12 and 13 and to avoid a sense of incongruity of the base isolation table 10 disposed on the floor. In FIG. 1, the seismic isolation table 10 is depicted thick for ease of explanation, but the thickness of the entire base isolation table 10 with the above configuration is only about 3.15 mm. Even if the carpet 51 is laid on top, there is no sense of incongruity.

  In FIG. 1, the entire TV base 53 is supported by a single large base 10, but the load is such that the supporting furniture is heavy and is on the legs 53 a of the TV base 53 illustrated. In the case where the pressure is concentrated on several points instead of on the plane, it is considered that stress is locally concentrated on the base 10 and the sliding between the sliding sheets 12 and 13 is not smooth. It is done. As a countermeasure in such a case, one is to place a rigid support plate such as a plywood board in place of the carpet 51 or in addition to the carpet 51, and place furniture on it to distribute the load. You may make it make it. As an alternative to this, a plurality of small seismic isolation tables 10 may be prepared, and a small support plate placed thereon may be interposed between each leg 53a and the floor surface 50.

  The base isolation table 10 according to the present embodiment configured as described above operates as follows. Due to the occurrence of the earthquake, the vibration is first transmitted to the floor 50. This shaking is transmitted to the first cushion sheet 11 and then transmitted to the first sliding sheet 12 that is tightly fixed thereto. However, since the friction coefficient between the first sliding sheet 12 and the second sliding sheet 13 is low, the latter follows the former up to a certain limit. , 13 occurs. The second sliding sheet 13 is tightly fixed to the second cushion sheet 14, and the shaking of the floor surface 50 is not transmitted as it is to the television stand 53 located above due to the occurrence of sliding.

The strength of an earthquake is generally expressed in “seismic intensity”. According to the “Earthquake Damage Assumption Support Manual” published by the Cabinet Office, there is the following relationship between “seismic intensity” and “acceleration (gal)” of an earthquake.
Seismic intensity: ~ 4 ~ 5 weak ~ 5 strong ~ 6 weak ~ 6 strong ~ 7
Acceleration (gal): ~ 100 ~ 240 ~ 520 ~ 830 ~ 1470 1471 ~

  According to the experiments conducted by the inventors of the present application, when the base isolation table 10 shown in the present embodiment is used, the slip between the sliding sheets 12 and 13 until the input acceleration (acceleration of earthquake) is about 200 gal. Although very little, a significant slip begins when the input acceleration exceeds about 200 gal. For example, when the input acceleration is 500 gal, the response acceleration in the upper TV stand 53 is reduced to about 200 gal. That is, even when an earthquake with a seismic intensity of about 5 is generated, the seismic intensity transmitted to the TV stand 53 is reduced to about 5 or less. This means that even if the input acceleration is 200 gal or more, the response acceleration is almost maintained at 200 gal. As a result, there is a possibility that the TV 52 that may have collapsed may be maintained without collapsing in the event of an earthquake with a seismic intensity of 5 or higher.

When viewed in terms of earthquake frequency, it is said that the dominant frequency (frequency with the largest amplitude) of most earthquakes is 1 Hz to 6 Hz. Among them, earthquakes with a dominant frequency of 1 Hz to 3 Hz have led to the fall of furniture and the collapse of houses. The results of calculating the seismic intensity and the amplitude (cm) at frequencies of 1 Hz, 2 Hz, and 3 Hz according to the above-mentioned manual using the acceleration and frequency equations by sine waves are shown below.
Seismic intensity: ~ 4 ~ 5 weak ~ 5 strong ~ 6 weak ~ 6 strong ~ 7
Amplitude (1Hz): ~ ± 2.5 ~ ± 6.0 ~ ± 13 ~ ± 21 ~ ± 37 ± 37 ~
Amplitude (2Hz): ~ ± 0.6 ~ ± 1.5 ~ ± 3.3 ~ ± 5.3 ~ ± 9.5 ± 9.5 ~
Amplitude (3Hz): ~ ± 0.3 ~ ± 0.7 ~ ± 1.5 ~ ± 2.3 ~ ± 4.2 ± 4.2 ~
According to this, when the seismic isolation table 10 according to the present invention is used, when an earthquake having a seismic intensity of 5 or higher occurs in the above example, if the frequency is 1 Hz, the television 52 shown in FIG. It can be seen that the amplitude due to an earthquake of 13 cm can be reduced to 6 cm, which is less than half of that. Even if the frequency is 2 Hz or 3 Hz, it is the same that the frequency becomes less than half (3.3 cm → 1.5 cm, 1.5 cm → 0.7 cm, respectively). It turns out that it is remarkable.

  As described above, the base isolation table 10 according to the present embodiment can be configured with a very simple structure using the action of “sliding” and can obtain an effective base isolation effect. In FIG. 1, the first cushion sheet 11 and the first sliding sheet 12 are longer than the second sliding sheet 13 and the second cushion sheet 14 because of the amplitude at the time of the earthquake. The movement allowance s in which both of them move relative to each other is anticipated. The magnitude of the movement allowance s can be estimated from the above-described relationship between seismic intensity and amplitude. When the frequency of the seismic wave is increased, the amplitude is very small. Conversely, when the frequency is decreased, the amplitude is increased. The travel allowance s that can be handled by any earthquake is thought to be about 40 cm. However, because there are restrictions on the installation location of furniture, etc., the travel allowance s is set to 15 cm in the example shown. For earthquakes with a frequency of 2 Hz or higher up to 5+, seismic intensity 7 is also available. After the earthquake has settled, if a residual displacement occurs between the two and the origin is restored, the original position can be easily restored by moving the carpet 51 together with the TV stand 53. It is desirable that the carpet 51 has a size that covers a movement allowance portion of the first cushion sheet 12 that is opened upward, in order to prevent foreign matter from entering between the sliding surfaces.

  It should be noted that in high-rise buildings, the secondary mode and the tertiary mode may sway, so when using such indoors, it is one countermeasure to keep the moving allowance s large. However, there is no particular problem even if the second sliding sheet 13 on the furniture side moves further beyond the movement allowance s. As other measures, it is conceivable to use two or more base isolation tables 10 as described above, thereby securing a movement amount, which will be described later. The base 10 using the sliding action mainly absorbs vibrations in the X (for example, north-south) and Y (same as east-west) directions with the ground surface as the coordinate plane. It has been clarified through experiments conducted by the inventors of the present application that an effect of absorbing vibrations in the Z direction perpendicular to the ground surface can be obtained by the damping action of this, and this will also be described in a later embodiment. .

When the base isolation table using the sliding action according to the present invention is compared with the base isolation table according to the prior art, the following significant advantages are observed.
1) The structure is simple and the cost is greatly reduced as compared with the prior art.
2) Installation, removal and management are extremely easy.
3) Therefore, it can be used for a wide range of objects from small items such as desks in general households to factory equipment.
4) Since the sliding is simple, there is no mechanical failure, the durability of the sliding sheet (especially the fluororesin sheet) is high, it is maintenance-free and can be used stably for many years.

  Next, a base isolation table according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a base isolation table 20 according to the present embodiment (the front half is cut to show a cross section). Here, the base isolation base 20 is shown as a unitized product. In FIG. 2, the base isolation table 20 includes a first cushion sheet 11, a first sliding sheet 12, a second sliding sheet 13, and a second cushion sheet 14. This configuration is the same as the previous implementation. This is the same as the base isolation table 10 according to the form. In addition to this, the base isolation table 20 according to the present embodiment includes a frame body 21, an optional support plate 22 that covers the second cushion sheet 14, the first cushion sheet 11, and the first slide. It further includes a cushioning material 23 that covers the movement allowance provided around the moving sheet 12. The first cushion sheet 11 and the first sliding sheet 12 are dimensioned so that they fit snugly within the frame body 21. The second sliding sheet 13 and the second cushion sheet 14 having a small area corresponding to the movement allowance, and the support plate 22 are laid thereon, and a plate-shaped cushioning material is placed on the movement allowance remaining on the entire circumference. 23 is arranged.

  The frame body 21 holds sheets and determines the limit of the relative sliding. The frame 21 has a rigid structure that can be manufactured from, for example, metal, plastic, wood, or the like. The support plate 22 transmits a load of equipment or the like to be placed on the support plate 22 so that the load is equally distributed to the second cushion sheet 14, thereby local stress concentration on the second cushion sheet 14. It is something to avoid. For example, when a thing with legs, such as a desk or a piano, is mounted, it is preferable to provide the support plate 22. However, in the case of a box or a device having a flat bottom surface, it is directly on the second cushion sheet 14 as it is. The bearing plate 22 can be treated as an option. The support plate 22 can be manufactured from metal, plywood, particle board, plastic, or the like.

  Although it is conceivable that the frame body 21 and the support plate 22 are partially fixed with a string-like low-hardness rubber, mixing of dust is inevitable. The cushioning material 23 makes the base 10 smoothly move during an earthquake, prevents dust, dirt and foreign matter from entering the sliding surface, and has a function of returning to the origin. The buffer material 23 is preferably made of a weather-resistant rubber material. In FIG. 2, an example of the cross-sectional shape of the buffer material 23 is shown. Here, groove-like dents are alternately provided on the front and back sides of the belt-like cross section, and the cross section has a so-called bellows shape. The planar rectangular base 20 shown in the figure is configured such that the plate-like cushioning material 23 divided into four parts on the left and right and top and bottom is arranged with no gap corresponding to each side. You may shape | mold integrally according to the inner side shape of the body 21. FIG. In FIG. 2, the cushioning material 23 is displayed thick. This is because the sheets 11 to 14 are depicted thick for display purposes. The width direction is much longer than the thickness direction in the figure (in the example of the previous embodiment, the thickness is about 10 mm (the thickness of the support plate 22 is about 8 mm), while the width is Is about 150 mm (width s in FIG. 1). In addition, the thickness of the support plate 22 and the buffer material 23 can be set in consideration of various conditions. For example, when the width of furniture or the like is wide and it protrudes from the width of the support plate 22, the obstacle plate is prevented from being restrained at the bottom of the furniture or the like by the cushioning material 23 being compressed by an earthquake and folded in a bellows shape. It is desirable to expect the thickness of 23 to be large.

  The operation of the base isolation table 20 configured as described above is basically the same as that of the base isolation table 10 in the previous embodiment. The seismic isolation table 20 according to the present embodiment makes it possible to carry out commercial transactions in units using the entire elements shown in FIG. 2 as a kit. The purchaser only needs to obtain a unit of the required size and shape and install it at the required location inside or outside the building. After that, furniture to be protected is placed on the base isolation table 20. When an earthquake occurs, the support plate 22 and the second sliding sheet 13 and the second cushion sheet 14 move relative to the frame body 21 by the sliding action in the base isolation table 20. Accordingly, the buffer material 23 is compressed and expanded. Particularly on the compression side, the cushioning material 23 is compressed between the support plate 22 and the frame body 21. Since the cushioning material 23 has a substantially bellows cross-sectional shape, the resistance increases as it is compressed, which may cause an unnecessary impact load due to the shaking of the earthquake to be applied to the furniture arranged on the support plate 22. It can be avoided and return to origin is also possible. In addition, the structure can prevent dust and dirt from entering the sliding surface.

  In the example shown in FIG. 2, a locking tool 24 indicated by a broken line connecting the frame body 21 and the support plate 22 is provided. The locking tool 24 is fixed to the frame body 21 side, and is configured to be detachable from the support plate 22. The locking tool 24 is a restraining mechanism provided on the base isolation table 20. When this is set, the sliding between the sliding sheets 12 and 13 is restrained. For locking, a fitting mechanism, an insertion mechanism, a magic tape (registered trademark: Magic Band), or the like can be used. The locking tool 24 is used for temporarily avoiding the sliding motion on the base isolation table 20 when, for example, a pallet with products placed on the base isolation base 20 is picked up by a fork lifter. Is done. This may be used similarly in the base isolation table shown in other embodiments. At this time, the first cushion sheet 11 and the second cushion sheet 14, or the first sliding sheet, even if the frame body 21 and the support plate 22 are not included as shown in the first embodiment. A locking tool 24 such as Velcro (registered trademark) that fixes the second sliding sheet 13 and the second sliding sheet 13 can be used.

  It should be noted that the term “inside and outside of the building” is not limited to the use of the seismic isolation table according to the present invention only inside the building. It means that it can be used for storage. However, it is excluded for application to the anti-vibration measures of the building itself.

FIG. 3 shows another aspect of the base isolation table 20 according to the present embodiment. Here, the base 20 is formed in a substantially circular plane, and the first cushion sheet 11 and the first sliding sheet 12 are arranged so as to fit inside the substantially circular frame body 21. A second sliding sheet 13 having a small area, a second cushion sheet 14, and an optional support plate 22 are arranged on the top. An annular cushioning material 23 is arranged above the movement allowance between the two, thereby forming a unit. A locking tool 24 indicated by a broken line may be further provided.

  As is clear from FIGS. 2 and 3, the size and shape of the base isolation table 20 according to the present embodiment can be arbitrarily selected. In the form shown in FIG. 2, it can be applied to a desk in an office or equipment in a factory, and further to the entire floor of a building. In the form shown in FIG. 3, one small thing may be arrange | positioned to each leg, such as equipment, or a large thing may be used independently for equipment.

  Next, a base isolation table according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 4A shows the base isolation table 30 according to the present embodiment, and the base isolation base 30 is the same as that shown in FIG. 1 in the first cushion sheet 11 and the first sliding sheet 12. The second sliding sheet 13 and the second cushion sheet 14 are formed to overlap in that order. The figure schematically shows an example in which a rubber-based waterproof sheet having a thickness of 1.5 mm, which is rich in flexibility, is used as the cushion sheets 11 and 14. The base isolation table 30 of the present embodiment is characterized in that each of these sheets is joined at least at a part of the periphery, preferably at the entire periphery. The joining method is arbitrary as long as a predetermined joining strength can be obtained, such as adhesion and fusion. A support plate 31 is preferably placed on the base isolation table 30, and furniture and the like are disposed on the support plate 31.

  FIG. 4B shows the situation of the base isolation table 30 when an earthquake occurs. Due to the shaking of the earthquake, the support plate 31 located on the furniture or the like (not shown) side is the second sliding sheet relative to the first cushion sheet 11 and the first sliding sheet 12 located on the floor surface side. It slides in the direction shown by arrow A in the figure together with 13 and the second cushion sheet 14, and moves relative to each other. At this time, there is no restriction on relative movement as long as the two are simply in contact as shown in FIG. 1, but in the base isolation table 30 according to the present embodiment in which the sheets are joined together, As shown in FIG. 4 (b), each sheet is lifted up and deformed while the surrounding joints are restrained by the relative movement of the two. The larger the relative movement amount, the larger the deformation, and the greater the deformation, the greater the resistance against sliding. This resistance exerts an effect of suppressing the amount of movement of furniture or the like placed on the upper side to a certain limit. In addition, a force that causes the deformation caused by the relative movement to return to the original state acts, and this becomes a constant origin return force that attempts to return the relative movement amount to the original state.

A further advantage of the base isolation table 30 according to the present embodiment configured as described above is that moisture and dust enter the sliding surface from the periphery, particularly when the periphery of each sheet is joined. And good low coefficient of friction can be maintained over a long period of time. In addition, since the unit only in a sheet material having flexibility is Ru is configured, wound, and the like that facilitates commercial distribution even relatively large size due to bending. The planar shape of the base isolation table 30 is not limited to the illustrated rectangular shape, and can be arbitrarily selected, such as a circular shape.

  Next, a base isolation table according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 5A shows a base isolation table 40 according to the present embodiment, and the base isolation table 40 includes a first cushion sheet 11 and a first sliding sheet 12 similar to those shown in FIG. A first sliding member 41 comprising: a second sliding member comprising the second sliding sheet 13 and the second cushion sheet 14; and an elastic connecting member 43 (43a) for connecting both of them together. 43b, 43c, 43d). The thickness x width x length of the ultra-low hardness rubber of the elastic connecting member 43 is determined so that the impact energy determined by the weight of furniture and the speed of the earthquake, which will be described later, and the absorbed energy of the elastic connecting member 43 have the same value. be able to. In addition, the size can be determined after experimentally determining the effect. In the present embodiment, a gel-like sheet having an elongation at break of about 1600% is used as the elastic connecting member 43. More specifically, low hardness styrene / butadiene elastomer (TPS), urethane elastomer ( TPU) and EPDM vulcanized rubber can be used. Both ends of the elastic connecting member 43 are joined to the first and second sliding members 41 and 42 by appropriate means such as adhesion and fusion. The joining at this time may be such that the first and second sliding members 41 and 42 are joined indirectly through another member.

  The operation of the base isolation table 40 configured as described above at the time of earthquake occurrence is as follows: the first sliding member 41 placed on the floor surface side and the second sliding member 42 placed on the furniture side or the like. However, the sliding movement between the sliding sheets 12 and 13 causes relative movement as shown by the arrows in FIG. The direction of the arrow shown in the figure is an example, and actually moves relative to any direction. The operation during this time is the same as in the previous embodiments. In the base isolation table 40 according to the present embodiment, the elastic connecting member 43 disposed around the base is pulled and extended by the sliding members 41 and 42 that move relative to each other. For example, if the thickness of each of the first and second sliding members 41 and 42 is 5 mm, the side surface height of the elastic connecting member 43 is about 10 mm in total, and if the breaking elongation is 1600%, the maximum is 16 cm. It will be allowed to elongate. With this extension allowance, it is possible to sufficiently cope with the 15 cm transfer allowance shown in the example of the first embodiment. As a matter of course, a larger stretch allowance can be obtained by making the height portion of the elastic connecting member 43 longer. Further, 1600% of the elongation at break is an example, and may be more or less as long as a desired elongation can be obtained.

  In the case where the base isolation table 10 is composed of only a pair of sliding members as in the example shown in the first embodiment, the amount of movement increases due to inertia or movement because of the free movement due to relative sliding. Later, both sliding members remain in a relatively displaced position. In the base isolation table 40 according to the present embodiment, the first and second sliding members 41 and 42 are connected by the elastic connecting member 43, so that the elastic connection is increased as the relative movement amount of both the sliding members 41 and 42 increases. A reaction force is exerted in the direction in which the member 43 contracts, and a vibration damping function for limiting the relative movement amount is achieved (see Example 3).

  A further advantage of providing the elastic connecting member 43 is to provide a restoring force for returning the sliding members 41 and 42 after the relative movement to the original position without any initial deviation. Especially when the weight of furniture etc. is excessively heavy, even if the return to origin is not performed instantaneously, the return to the origin is gradually restored due to vibrations caused by some factors in the surroundings by continuously acting the restoring force. (See Example 3).

  The elastic connecting member 43 is not necessarily divided into four parts (43a to 43d) as illustrated, and may be configured as a pair of connecting members facing a pair of opposite sides as long as sufficient strength can be obtained. Good. Or it is also possible to shape | mold as an integral member with the annular collar which covers the whole circumference | surroundings of the base isolation table 40 with a slip. By configuring in this way, the planar shape of the base isolation table 40 is not limited to a rectangle. For example, even if it is substantially circular, the same effect can be obtained by covering the periphery with a substantially circular elastic connecting member 43. be able to. When the periphery of the base isolation table 40 is completely covered by the elastic connecting member 43, an effect of preventing dust and dirt from entering between the sliding sheets 12 and 13 can be obtained. Even if the periphery is not completely covered and the elastic connecting member 43 is divided as shown in the figure, the width of each elastic connecting member 43a to 43d is the length of the corresponding side of both sliding members 41 and 42. By taking close to and broadening, almost the same effect can be obtained.

  FIG. 6 shows another application example of the base isolation table 40 according to the present embodiment. Here, a vibration absorbing material 45 for absorbing vertical vibration is fixed on the second sliding member 42 of the base isolation table 40. Fixing is possible, for example, by adhesion. As the material of the vibration absorbing material 45, rubber can be used, but considering the damping capacity, a used rubber tire chip board shape obtained by grinding a used waste tire or industrial rubber parts into a flat plate shape. The body is preferably used as a vibration absorbing material. In the illustrated example, a vibration absorbing material 45 made of a tire chip having a thickness of 10 mm is used. Even in the base isolation table 10 shown in the first embodiment, the first and second cushion sheets 11 and 14 alone have a vibration absorption effect in the vertical direction. By adding the absorbent material 45, it is possible to more effectively absorb the vertical vibration associated with the earthquake and enhance the effect of reducing the damage. The horizontal vibration absorption is the same as in the fourth embodiment described above. The use of tire chips, which are waste materials, also contributes to environmental protection.

  The above-described use of the vibration absorbing material 45 that absorbs vibration in the vertical direction can be similarly applied to the first to third embodiments described above. In the above-described example, the vibration absorbing material 45 is provided on the second sliding member 42 side on the furniture side, but this is provided on the first sliding member 41 side on the floor surface side. Even if it is provided on both sides, the same effect can be obtained.

  As mentioned above, although the base isolation table which concerns on each embodiment of this invention has been demonstrated, various improvement is possible for each base isolation base. For example, the carpet 51 shown in FIG. 1 can be removed by applying decoration on the upper surface of the second cushion sheet 14 positioned on the upper side, for example, by flocking. In addition, without providing the support plates 22 and 31 as separate elements on the second cushion sheet 14, it is possible to bak the rubber material as the cushion sheet on the support plate itself so as to be integrated. Alternatively, in the example shown in FIG. 1, the base isolation table 10 according to the present invention can be included between the outer surface and the lining of the carpet, and configured as a carpet having a base isolation effect.

  Furthermore, the present invention also includes a seismic isolation method using the configuration of the base isolation table according to each aspect described above. That is, the seismic isolation method according to the present invention comprises a base isolation base by overlapping a pair of sliding members related to a combination of a sliding sheet made of a low friction material and a cushion sheet so that the sliding sheets face each other. The base isolation table is interposed between the floor of the building and the furniture, etc., and is transmitted from the floor to the furniture by the sliding action between the pair of sliding sheets and by the damping action of the pair of cushion sheets. The method is characterized by reducing vibration caused by an earthquake. The pair of sliding sheets may be installed so as to substantially cover the floor surface inside the building and provide a seismic isolation effect for all furniture and the like in the building.

  Moreover, the seismic isolation base which consists of a pair of sliding member is not restricted to single, and it can also use plurally and can heighten the seismic isolation effect. In particular, in a high-rise building, the amplitude in the left-right direction may be amplified by resonance or by long-period vibration. By laying a plurality of seismic isolation tables, it is possible to further reduce the degree of influence on furniture and the like accompanying such an increase in amplitude. In the case of the structure of the base isolation table provided with the elastic coupling member shown in the fourth embodiment, the stress balance displacement can be increased by stacking the base isolation tables in multiple layers (see Example 4). .

上記結果より、いずれの組み合わせにおいても、鉛直荷重によって摩擦係数は大きな差はないことが確認できた。中でも、フッ素樹脂シート／フッ素樹脂シートの組み合わせによる摩擦係数が最も良好であり、次いで僅かな差ではあるがフッ素樹脂トート／超高分子樹脂シートの組み合わせが挙げられる。超高分子樹脂シート同士の組合せは摩擦係数が０．４を上回るものとなり、摺動効果はやや劣るものとなる。なお、本明細書でいう「低摩擦係数」、もしくは「低摩擦材」における摩擦係数は、この超高分子樹脂シート同士の組合せを限度とするもので、具体的には静摩擦係数が０．４３以下であることを意味するものとする。 The static friction coefficient by the combination of the fluororesin sheet and the ultra high polymer resin sheet was measured using a test piece and verified.
1. Sample size 300x300mm
2. Configuration Sliding sheet (0.2mm) (1) Fluororesin sheet Made by Honda Sangyo Co., Ltd.
(2) Ultra high molecular weight polyethylene sheet Atsugi Hutec

From the above results, it was confirmed that the friction coefficient was not significantly different depending on the vertical load in any combination. Among them, the friction coefficient by the combination of the fluororesin sheet / fluororesin sheet is the best, and then the combination of the fluororesin tote / ultra high molecular resin sheet is mentioned with a slight difference. The combination of the ultra-polymer resin sheets has a friction coefficient exceeding 0.4, and the sliding effect is slightly inferior. In addition, the friction coefficient in the “low friction coefficient” or “low friction material” in this specification is limited to the combination of the ultrahigh polymer resin sheets, and specifically, the static friction coefficient is 0.43. It shall mean the following.

The input acceleration and response acceleration of the base isolation table according to the present invention were measured in the Tohoku-Pacific Ocean Earthquake of March 11, 2011 and the aftershocks thereafter. Asphalt sheet (1.5 mm thickness), fluororesin sheet (0.075 mm thickness) / fluororesin sheet (0.075 mm thickness), ballast mat (25 mm thickness), which is almost the same as the base isolation table according to the first embodiment A sensor was installed on a seismic isolation table with a sliding structure consisting of a combination of the above, and input acceleration and response acceleration were measured using a PC-connected seismometer (manufactured by Mathematical Design Laboratory). In Sagamihara City, Kanagawa Prefecture where the test equipment was installed, the seismic intensity of each earthquake was less than 5, so the acceleration difference (vibration absorption) in the horizontal direction (north-south X direction and east-west Y direction) is not always clear. Although not captured, a vibration absorption effect in the vertical direction (Z direction) was observed. This seems to be the effect of laying a ballast mat (25 mm thick) as a cushion sheet. Tables 2 to 4 shown below show the measurement results at that time.

The reduction function and the restoration function by the elastic connecting member 43 of the base isolation table 40 according to the fourth embodiment were verified.
It is important that the performance required for the elastic connecting member is designed to increase the amount of displacement while suppressing the reaction force. In the case of the base isolation table 40 fixed with the elastic connecting member 43 made of ultra-low hardness rubber having a thickness of 2 mm × 4 cm on all four sides, and the elastic connecting member made of ultra-low hardness rubber having a thickness of 2 mm × 8 cm on all four sides. The reaction force and the amount of displacement when the base isolation table 40 fixed at 43 (see FIG. 5) is separately arranged at the lower corner portion of the support platform on which a weight of 40 kg is placed were obtained from the following relational expressions.
Relational expression between the collision energy of the floor and the absorbed energy of the base isolation table ½ · mv ² = ½ · kx ² (m: loading amount, v: speed, k: stress per unit elongation, x : Displacement amount), the amount of expansion displacement of both elastic connecting members 43 is calculated as follows assuming that the input acceleration is 500 gal and the frequency is 1.67 Hz.
2 mm thick × 8 cm wide elastic connecting member 43: 8.9 cm
2 mm thick × 4 cm wide elastic connecting member 43: 12.6 cm
As a result, the amount of displacement of elongation changes by changing the width, but by using a low-hardness elastic connecting member, the reaction force is suppressed, the amount of displacement is increased, the absorbed energy is increased, and the damping effect We were able to confirm that At the same time, the residual displacement was almost zero, and it was confirmed that there was a function to return to origin.

The effect of using multiple layers of seismic isolation tables was verified.
The first sliding member 41 of 5 mm thickness × 10 cm square and the second sliding member 42 of the same size are combined to constitute one seismic isolation table. Prepare one layer using one of these bases and two layers of bases.
An elastic connecting member having a thickness of 2 mm and a width of 4 cm is attached to the four sides of the base isolation table, and each of the first sliding member and the second layer of the base isolation base having two layers and the base isolation base having two layers are attached. The sliding member is connected with four sides. In this state, when a force in the sliding direction was applied to both under the same conditions and compared, it was found that the amount of displacement of the elongation stress was larger in the two-layer base isolation table than in the base isolation table having only one layer. That is, it was found that the amount of displacement of the stress balance can be increased by making the base isolation table provided with the elastic connecting member in multiple layers. As a result, it was confirmed that even if the amount of displacement due to the earthquake increases, the shock is small and it is possible to secure absorbed energy commensurate with the impact energy.

  The seismic isolation method and the base isolation table according to the present invention can be widely used in industrial fields where development, manufacture, sale, and use of seismic isolation members are planned.

10, 20, 30. 10. Base isolation table, 11. first cushion sheet, 12. first sliding sheet; Second sliding sheet, 14. Second cushion sheet, 21. Frame, 22, 31. Base plate, 23. Cushioning material, 24. Locking device, 40. Base isolation table, 41. First sliding member, 42. Second sliding member, 43. Elastic connecting member, 45. Vibration absorbing material, 50. Floor surface, 51. carpet.

Claims (8)

In the seismic isolation method to protect furniture, etc. arranged in or around the building from collapse or damage in the event of an earthquake,
The sliding sheet surfaces of both of the sliding members are opposed to each other in a pair of sliding members composed of a sliding sheet made of a low friction material and a cushion sheet stacked to back up the sliding sheet. The furniture is placed between the floor surface of the building and the furniture or the like by being overlapped with each other, and from the floor surface by the sliding action between the pair of opposed sliding sheets or by the damping action of the pair of cushion sheets. While reducing vibration caused by earthquakes transmitted to
By the pair of slide members are joined in all ambient, or by between the pair of sliding members are connected by elastic coupling members consisting of ultra low hardness rubber, relative displacement between the pair of slide members A seismic isolation method, wherein the amount is limited and the pair of sliding members moved relative to each other is returned to the origin.   A plurality of the pair of sliding members are overlapped and arranged between the floor surface of the building and the furniture, or the plurality of the sliding members are individually arranged between the floor surface of the building and the furniture, etc. The seismic isolation method according to claim 1, which is reduced.   The seismic isolation method according to claim 1 or 2, wherein a vibration absorbing member is attached to at least one of the pair of sliding members to further absorb vertical vibration due to an earthquake. In order to protect furniture or the like arranged in or around the building from collapse or damage in the event of an earthquake, a seismic isolation table arranged between the floor of the building and the furniture,
A pair of sliding members consisting of a sliding sheet made of a low friction material and a cushion sheet overlaid to back it up;
An elastic connecting member made of ultra-low hardness rubber connecting at least a part of the periphery of the pair of sliding members;
The surfaces of the sliding sheets of the pair of sliding members are overlapped so as to face each other, and the sliding action between the sliding sheets or the damping action of the cushion sheet reduces vibration caused by an earthquake,
The base isolation table, wherein the elastic connecting member limits a relative displacement amount of the pair of sliding members, and returns a relative movement between the pair of sliding members to return the origin. In order to protect furniture or the like arranged in or around the building from collapse or damage in the event of an earthquake, a seismic isolation table arranged between the floor of the building and the furniture,
Consists of a pair of sliding members consisting of a sliding sheet made of a low friction material and a cushion sheet that is overlaid to back it up,
The surfaces of the sliding sheets of the pair of sliding members are overlapped so as to face each other, and the sliding action between the sliding sheets or the damping action of the cushion sheet reduces vibration caused by an earthquake,
Around the sliding member arranged on the floor surface side of the pair of sliding members, the movement allowance for the relative movement of both sliding members is relative to the sliding member arranged on the furniture etc. side Extra,
The sliding member arranged on the floor surface side is arranged in the frame body, and a cushioning material that cushions the movement of the sliding member arranged on the furniture side with respect to the frame body is put on the movement allowance. A base-isolated table characterized by   The base isolation table according to claim 4, further comprising a releasable restraint mechanism that accepts or restrains relative movement between the pair of sliding members.   The immunity according to any one of claims 4 to 6, wherein a vibration absorbing member that further absorbs vertical vibration caused by an earthquake is attached to at least one cushion sheet of the pair of sliding members. Shaking table. In order to protect furniture or the like arranged in or around the building from collapse or damage in the event of an earthquake, a seismic isolation table arranged between the floor of the building and the furniture,
Consists of a pair of sliding members consisting of a sliding sheet made of a low friction material and a cushion sheet that is overlaid to back it up,
The surfaces of the sliding sheets of the pair of sliding members are overlapped so as to face each other, and the sliding action between the sliding sheets or the damping action of the cushion sheet reduces vibration caused by an earthquake,
The circumferential囲全member of the pair of slide members are joined to limit the relative displacement amount between the pair of sliding members, the pair of slide members move relative characterized in that to homing MenShindai .

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