JP6945758B1 - Sliding seismic isolation device and seismic isolation bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slip seismic isolation device and a seismic isolation bearing which are excellent in dustproof property on a sliding surface constituting the slip seismic isolation device and can guarantee a friction coefficient at the time of design. SOLUTION: A pedestal 43 having a sphere 44 having a first concave spherical surface 44a and a first convex spherical surface 45b housed in the first concave spherical surface 44a are provided on the opposite side of the first convex spherical surface 45b. A slip seismic isolation device 40 having a sliding body 45 having a second convex spherical surface 45a and a shoe 41 having a second concave spherical surface 41c on which the second convex spherical surface 45a slides, and the shoe 41 is dustproof. The sheet 50 is attached, and a part of the dustproof sheet 50 extending from the shoe 41 toward the pedestal 43 is in contact with the pedestal 43. [Selection diagram] Fig. 2

Description

The present invention relates to a slip seismic isolation device and a seismic isolation bearing.

In Japan, which is an earthquake-prone country, various structures such as buildings, bridges, elevated roads, and detached houses are subject to various seismic isolation, such as technology to resist seismic force and technology to reduce seismic force entering structures. Technology, seismic isolation technology and vibration control technology have been developed and applied to various structures. Above all, since the seismic isolation technology is a technology for reducing the seismic force itself entering the structure, the vibration of the structure at the time of an earthquake is effectively reduced. To outline this seismic isolation technology, a seismic isolation device is interposed between the substructure and the superstructure to reduce the transmission of the vibration of the substructure to the superstructure due to the earthquake, and the vibration of the superstructure is reduced. It reduces and guarantees structural stability.

There are various types of seismic isolation devices such as lead plug-filled laminated rubber bearing devices, high-damping laminated rubber bearing devices, devices that combine laminated rubber bearings and dampers, and slip seismic isolation devices. Among them, the sliding seismic isolation device includes a flat surface sliding seismic isolation device and a spherical sliding seismic isolation device. The flat surface sliding seismic isolation device does not have a restoring force, but the spherical sliding seismic isolation device has a restoring force and an earthquake. Has a self-centering function at the time. Here, to explain the configuration by taking an example of the spherical sliding seismic isolation device, a pedestal provided with a ball seat, a sliding body (slider) rotatably housed in the ball seat, and a surface of the sliding body. It is a sliding seismic isolation device having a sliding sill, and this type of sliding seismic isolation device is sometimes called a single concave type seismic isolation device (sliding seismic isolation device with single-sided sliding bearings).

By the way, in the sliding seismic isolation device, the restoring force characteristics of the sliding seismic isolation device are adjusted by adjusting the curvature of the sliding surface of the shoe, the curvature of the sliding surface of the sliding body, and the friction coefficient. Therefore, if dust or dirt adheres to the sliding surface of the shoe or the sliding body, the friction coefficient of the sliding seismic isolation device may change from the friction coefficient at the time of design. It is desirable to take measures to prevent dust from adhering.

Here, Patent Document 1 proposes a method of installing a sliding bearing. Specifically, a sliding bearing provided with a sliding plate, a sliding material on which the sliding plate is slidable, and a holder for supporting the sliding material at the bottom is installed between the foundation and the foundation beam of the building. , How to install a slip bearing. In this installation method, the sliding material and the sliding plate are placed at predetermined relative positions, one end is fixed to the holder, and the other end is fixed to the sliding plate, and a fixing member is provided to integrate the sliding bearing in advance. After installing the integrated sliding bearing in a predetermined position, the fixing member is removed from the sliding plate. In this installation method, one end of the fixing member is fixed to the holder and the other end is in contact with the sliding plate to cover the sliding area surrounded by the sliding material, the sliding plate, and the holder. A dustproof sheet is provided.

Japanese Unexamined Patent Publication No. 2007-16433

According to the method of installing the sliding bearing described in Patent Document 1, the dust-proof sheet can prevent dust in the sliding region, so that dust does not adhere to the sliding material or the sliding plate in the sliding region, and the sliding It is said that durability related to dynamic performance can be ensured. By the way, in the installation method described in Patent Document 1, since the sliding region is covered in a manner in which the dustproof sheet is brought into contact with the sliding plate, the dustproof sheet itself may change the friction coefficient of the sliding bearing. In addition, there is a sufficient possibility that the dustproof sheet will be caught in the fixing member in the process of sliding the sliding material, and there are doubts about the performance and reliability of the slip seismic isolation device.

The present invention has been made in view of the above problems, and is a slip seismic isolation device and a seismic isolation bearing that are excellent in dust resistance to the sliding surface constituting the slide seismic isolation device and can guarantee the friction coefficient at the time of design. Is intended to provide.

In order to achieve the above object, one aspect of the slip seismic isolation device according to the present invention is
A pedestal with a tee with a first concave spherical surface,
A sliding body having a first convex spherical surface accommodated in the first concave spherical surface and a second convex spherical surface on the opposite side of the first convex spherical surface.
With a shoe having a second concave spherical surface on which the second convex spherical surface slides,
A dustproof sheet is attached to the shoe, and a part of the dustproof sheet extending from the shoe toward the cradle is in contact with the cradle.

According to this aspect, a dustproof sheet is attached to the shoe (which may be the upper shoe or the lower shoe) that constitutes the single concave type (single type) sliding seismic isolation device, and the dustproof sheet is attached from the shoe toward the cradle. Since a part of the extended dustproof sheet is in contact with the cradle, the sliding surface provided by the shoe (second concave spherical surface) and the sliding surface provided by the sliding body (first convex spherical surface or second convex spherical surface). , There is no risk that the dustproof sheet will get caught in all the sliding surfaces such as the first concave spherical surface provided by the ball seat of the cradle, and further, the adhesion of dust etc. to each sliding surface is suppressed, and friction at the time of design It is a slip seismic isolation device with a guaranteed coefficient.

Here, the "dustproof sheet extending from the shoe to the cradle" means that the dustproof sheet attached to the upper shoe reaches the cradle in the form where the cradle is below and the shoe is the upper sill. It means that it is hung down, and this form further includes a form in which the lower part of the dustproof sheet is in contact with the cradle and a form in which the lower part of the dustproof sheet is fixed to the cradle. On the other hand, in the form in which the cradle is on the upper side and the shoe is the lower shoe, one end of the dustproof sheet is fixed to the lower shoe and the other end of the dustproof sheet is fixed to the cradle. Further, "a part of the dustproof sheet is in contact with the cradle" means, for example, that when the shoe is an upper shoe, the lower part of the dustproof sheet is in contact with the side surface of the cradle, or the cradle. It includes a form in contact with the outer region of the sphere on the upper surface of the ball. Further, as the dustproof sheet, a resin sheet or the like represented by rubber such as synthetic rubber or natural rubber is applied.

When the plan view shape of the shoe is rectangular, for example, by attaching dustproof sheets to four side surfaces (all side surfaces), the inside of the slip seismic isolation device can be completely surrounded by the dustproof sheets. When the plan view shape of the shoe is circular or elliptical, a dustproof sheet is attached to the entire circumference of the side surface of the shoe, and for example, by providing slits in the dustproof sheet at regular intervals, the edges are cut by the slits. A part of each dustproof sheet can be brought into contact with the cradle while guaranteeing good deformability of each dustproof sheet.

In addition, another aspect of the slip seismic isolation device according to the present invention is
It is characterized in that a part of the dustproof sheet is pressed against the side surface of the shoe with a pressing plate.

According to this aspect, since a part of the dustproof sheet is pressed against the side surface of the shoe with the pressing plate, the connection strength of the dustproof sheet to the shoe is increased and the dustproof sheet is attached. It is possible to suppress the fluttering and peeling of the dustproof sheet in the part.

In addition, another aspect of the slip seismic isolation device according to the present invention is
The dustproof sheet is attached to both the shoe and the cradle.
It is characterized in that the dustproof sheet is broken when the shoe is displaced relative to the cradle by the action of a horizontal load due to a predetermined seismic motion.

According to this aspect, in the form in which the dustproof sheet is attached to both the shoe and the cradle, the dustproof sheet is always broken when a horizontal load due to a predetermined seismic motion acts and the shoe is relatively displaced. The internal space between the shoe and the cradle (the space where the sliding surface exists) is closed (or sealed) from the outside, and while having high dust resistance, the dustproof sheet is used when a predetermined earthquake motion acts. By breaking it, it is possible to prevent the dustproof sheet from hindering the relative displacement between the cradle and the shoe.

Here, the predetermined seismic motion is a level 2 seismic motion that occurs extremely rarely (about once every 500 years), or a level 3 seismic motion that is the largest unexpected earthquake and has a larger scale than the level 2 seismic motion. Seismic motion and the like can be mentioned. When a horizontal load due to such a large-scale earthquake motion acts and the shoe is displaced relative to each other, the resin sheet such as rubber and the dustproof sheet such as a fiber-based sheet will naturally break due to insufficient strength. .. In addition, a break line or the like may be provided at an intermediate position of the dustproof sheet so that the dustproof sheet breaks around the break line when a horizontal load is applied.

In addition, another aspect of the slip seismic isolation device according to the present invention is
A pair of movement direction regulating jigs straddling the shoe and the pedestal are fixed to either the shoe and the pedestal, and are not fixed to the other of the shoe and the pedestal. The horizontal displacement of the other shoe or cradle in a predetermined direction is regulated by the movement direction regulating jig.
The movement direction regulating jig includes a key portion, and the key portion is arranged at the end of the other shoe or cradle to regulate the vertical displacement of the other shoe or cradle.
The other shoe or pedestal is provided with a stopper ring that defines the sliding range of the sliding body, and a concave spherical and circular sliding surface inside the stopper ring.
The dustproof sheet is attached to at least the side surface of the shoe where the movement direction regulating jig does not exist.

According to this aspect, a pair of moving direction regulating jigs are fixed to either one of the stile and the pedestal, and the moving direction regulating jig is not fixed to either one of the stile and the pedestal. By freely shifting (moving) in the horizontal direction using the movement direction regulating jig as a guide, it is possible to regulate (restrict) the movement in a predetermined direction among the horizontal relative movements of the sill and the cradle. can. On top of that, the dustproof sheet is attached to the side surface where the movement direction regulation jig does not exist in the shoe, so that the pair of movement direction regulation jigs and the dustproof sheet block the internal space between the shoe and the cradle. Therefore, a slip seismic isolation device having high dust resistance can be formed. Here, "at least the dustproof sheet is attached to the side surface where the movement direction regulation jig does not exist" means that the dustproof sheet is attached only to the side surface where the movement direction regulation jig does not exist, and the movement direction regulation. In addition to the side surface where the jig does not exist, the meaning includes a form in which the dustproof sheet is attached to the side surface where the movement direction regulating jig exists.

This aspect can be applied to any structure such as a bridge, an elevated road, a house, etc. However, when this aspect is applied to a movable bearing of a bridge, the above-mentioned "predetermined direction" is, for example, a bridge shaft. The direction perpendicular to the bridge axis is an example. For example, the movement of the bearing in the direction perpendicular to the bridge axis is allowed, and the movement in the direction perpendicular to the bridge axis is restricted. For example, in the above-mentioned level 2 or lower earthquakes (level 1 earthquake and level 2 earthquake), it is permissible to freely horizontally displace the shoe in the direction of the bridge axis with respect to the cradle.

Further, in this embodiment, the moving direction regulating jig is provided with a key portion, and the key portion is arranged at the end of the other sill or the end of the cradle to which the moving direction regulating jig is not fixed. Therefore, the vertical displacement (vertical displacement) of the other jig or cradle can be regulated. Therefore, for example, when a lift force caused by a level 2 or higher earthquake (level 2 earthquake and an earthquake larger than level 2) acts on the shoe (upper shoe), the shoe comes into contact with the key part of the movement direction regulating jig. , Lifting of the shoe (an example of vertical displacement), etc. can be suppressed. By suppressing the lifting of the shoe, it is possible to prevent the shoe and the upper structure from falling off from the lower structure.

This aspect further includes a stopper ring that defines the sliding range of the sliding body on the sliding surface on which the sliding body slides on the other shoe or pedestal to which the moving direction regulating jig is not fixed. With this stopper ring, when a horizontal force due to an unexpected earthquake (such as when an earthquake larger than level 2 acts when assuming up to a level 2 earthquake) acts on the shoe (upper shoe), for example, the shoe Excessive horizontal displacement can be suppressed by the stopper ring. Here, as an example of the stopper ring, there is a form consisting of a columnar groove formed on the surface on which the sliding body slides among the other shoes or pedestals to which the movement direction regulating jig is not fixed. A concave spherical sliding surface is provided inside the stopper ring of the columnar groove. When the other shoe is an upper shoe, the second concave spherical surface described above becomes a concave spherical sliding surface. Further, as another example of the stopper ring, there is a form consisting of a ring-shaped protrusion provided on the surface on which the sliding body slides in the other shoe or pedestal, and inside the ring-shaped protrusion, A concave spherical sliding surface is provided.

As described above, in the slip seismic isolation device of this embodiment, the movement direction regulating jig, which is the first fail-safe mechanism, is fixed to one of the shoe or the cradle, and the other of the shoe or the cradle (the first fail). A stopper ring, which is a second fail-safe mechanism, is provided for the shoe or cradle on which the safe mechanism is not fixed. With these configurations, the movement direction regulation jig is used to regulate the movement direction of the cradle or cradle in the horizontal plane to which the movement direction regulation jig is not fixed, and the vertical displacement such as lifting due to the lifting force is regulated by the movement direction regulation. In addition, the sliding body can prevent excessive horizontal displacement of the stile or cradle on which the movement direction regulating jig is not fixed and the stopper ring is provided. It can be suppressed by contacting with.

Moreover, one aspect of the seismic isolation bearing according to the present invention is
The slip seismic isolation device is installed on the abutment or pier of the bridge.
The pair of movement direction regulating jigs are arranged in a direction perpendicular to the bridge axis, and the dustproof sheet is attached to a pair of side surfaces of the shoe in the bridge axis direction.

According to this aspect, the sliding seismic isolation device of the present invention forms a seismic isolation bearing on a bridge pedestal or a bridge pedestal, so that, for example, horizontal displacement such as a sill at all times or during an assumed earthquake can be suppressed and lifting can be suppressed. At the time of design, it is guaranteed, and while the suppression of excessive horizontal displacement such as the upper bridge in the event of an unexpected earthquake is guaranteed, the adhesion of dust, etc. to the sliding surface of the slip seismic isolation device is suppressed. The friction coefficient is guaranteed, and it is possible to provide a bridge that can exhibit sufficient seismic isolation performance against earthquakes of all sizes.

As can be understood from the above description, according to the sliding seismic isolation device and the seismic isolation bearing of the present invention, it is possible to have excellent dust resistance to the sliding surface constituting the sliding seismic isolation device and guarantee the friction coefficient at the time of design. can.

It is an exploded perspective view which shows by removing the dustproof sheet from the slip seismic isolation device in the state which an example of the slide seismic isolation device which concerns on embodiment is fixed to the top end of a pier. It is a perspective view which shows the state which an example of the sliding seismic isolation device which concerns on embodiment is fixed to the top end of a pier. It is a perspective view which shows the state which another example of the sliding seismic isolation device which concerns on embodiment is fixed to the top end of a pier. FIG. 1 is a vertical cross-sectional view of an example of a sliding seismic isolation device fixed to the top of a pier, which is a view taken along the line IV-IV of FIG. FIG. 5 is a vertical cross-sectional view of a state in which the seismic isolation bearing according to the embodiment is interposed between the upper structure and the lower structure as viewed from the direction of the bridge axis. FIG. 5 is a vertical cross-sectional view showing a state in which a horizontal force acts on the sliding seismic isolation device according to the embodiment in the direction of the bridge axis and the shoe is displaced relative to the cradle.

Hereinafter, the slip seismic isolation device and the seismic isolation bearing according to the embodiment will be described with reference to the attached drawings. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Sliding seismic isolation device and seismic isolation bearing according to the embodiment]
A plurality of examples of the sliding seismic isolation device and an example of seismic isolation bearings according to the embodiment will be described with reference to FIGS. 1 to 6. Here, FIG. 1 is an exploded perspective view showing an example of the sliding seismic isolation device according to the embodiment with the dustproof sheet removed from the sliding seismic isolation device in a state where the example is fixed to the top end of the pier. , Is a perspective view showing a state in which an example of the slip seismic isolation device according to the embodiment is fixed to the top end of a pier. Further, FIG. 3 is a perspective view showing a state in which another example of the sliding seismic isolation device according to the embodiment is fixed to the top end of the pier, and FIG. 4 is a view taken along the line IV-IV of FIG. It is a vertical cross-sectional view of an example of a slip seismic isolation device fixed to the top of a pier. Further, FIG. 5 is a vertical cross-sectional view of a state in which the seismic isolation bearing according to the embodiment is interposed between the upper structure and the lower structure as viewed from the direction of the bridge axis, and FIG. 6 is a vertical cross-sectional view of the embodiment. It is a vertical cross-sectional view which shows the state which the horizontal force acts on the said slip seismic isolation device in the direction of a bridge axis, and the bearing is relatively displaced with respect to a cradle.

In the illustrated example, the sliding seismic isolation device 40 and the seismic isolation bearing 60 formed by the sliding seismic isolation device 40 will be described as an example of forming a movable bearing or a fixed bearing of a bridge. The slip seismic isolation device 40 and the seismic isolation bearing 60 can be applied to various buildings such as elevated roads, buildings and condominiums in addition to bridges.

The bridge (not shown) to which the sliding seismic isolation device 40 is applied is a fixed bearing or a fixed bearing for a plurality of piers 20 (substructures) made of reinforced concrete, for example, which are arranged at intervals in the direction of the bridge axis. It is formed by supporting the superstructure 10 (see FIG. 5) via a sliding seismic isolation device 40 which is a movable bearing.

As shown in FIGS. 1 and 2, the sliding seismic isolation device 40 includes an upper shoe 41 (an example of a shoe), a lower shoe 43 (an example of a cradle), and a sliding body that is rotatable with respect to the pedestal 43. It is a sliding seismic isolation device having a single-sided sliding bearing, which has 45 and the shoe 41 is slidably configured with respect to the sliding body 45. Although not shown, in the slip seismic isolation device, in addition to the form shown in the illustrated example, the sliding body 45 is rotatably arranged with respect to the upper sill 41 (the upper sill is a pedestal), and the sliding body 45 is slid. The lower sill 43 may be slidably configured with respect to the moving body 45 (the lower sill is a sill), and a single-sided sliding bearing sliding seismic isolation device having a configuration that is upside down from the illustrated example may be used.

Both the shoe 41 and the cradle 43 are formed of rolled steel for welding steel (SM490A, B, C, or SN490B, C, or S45C), SUS material, cast steel material, cast iron, etc., and have different plane dimensions from each other. It has a viewing rectangle. In the illustrated example, the plane dimension of the cradle 43 is relatively large.

The upper surface of the shoe 41 is a flat structure support surface 41a that supports the upper structure. Engagement grooves 41b are provided on a pair of end sides of the structure support surface 41a. Further, on the upper surface of the cradle 43, two moving direction regulating jigs 47 including a block-shaped main body portion 47a and a key portion 47b protruding toward the shoe 41 in the upper part of the main body portion 47a are provided. Then, the key portion 47b of each movement direction regulating jig 47 is loosely fitted to the corresponding engaging groove 41b.

As is clear from FIG. 4, there is a gap between the engaging groove 41b of the stile 41 and the key portion 47b of the moving direction regulating jig 47, and between the lower surface of the key portion 47b and the bottom surface of the engaging groove 41b. Is provided with a gap 41f having a length t1 in the vertical direction, and a gap 41g having a length t2 in the horizontal direction is provided between the main body 47a and the outer peripheral surface of the key 41.

As shown in FIG. 4, at all times, the pair of left and right movement direction regulating jigs 47 and the shoe 41 are completely trimmed with gaps 41f and 41g from each other, and therefore, as shown in FIG. The shoe 41 that supports the superstructure (not shown) is movable in the direction of the bridge axis.

On the other hand, as shown in FIG. 4, a stopper ring 41d formed of a columnar groove is provided on the lower surface of the shoe 41, and the inside of the stopper ring 41d is a concave spherical sliding surface in a circular shape in a plan view. , A second concave spherical surface 41c is provided. A mating material 42 (sliding plate) made of stainless steel and having a circular shape in a plan view is fitted into the second concave spherical surface 41c. Further, the sliding surface of the mating material 42 is mirror-finished. The mating material 42 has a plan-viewing dimension larger than the plan-viewing dimensions of the stopper ring 41d and the second concave spherical surface 41c, and the mating material 42 having a relatively large plan-viewing dimension is second via the stopper ring 41d. By being fitted into the concave spherical surface 41c, a compressive force is generated in the mating material 42 in the radial direction, and the reaction force of this compressive force pushes the stopper ring 41d radially outward to form the second concave spherical surface 41c. On the other hand, the mating material 42 is firmly fixed.

As shown in FIG. 4, a ball seat 44 having a first concave spherical surface 44a (sliding surface) is detachably fixed to the upper surface of the pedestal 43 by a plurality of bolts (not shown). .. Here, the ball seat 44 is also made of the same material as the shoe 41 and the cradle 43.

Further, as shown in FIG. 4, the cradle 43 has a plurality of anchor bolt holes 43a through which a plurality of anchor bolts 22 protruding upward from the top end of the pier 20 are inserted, and a movement direction regulating jig 47. A plurality of bolt holes (not shown) corresponding to a plurality of bolt holes (not shown) are provided. As shown in FIG. 4, the anchor bolt 22 is inserted into the anchor bolt hole 43a of the pedestal 43, and the anchor bolt 22 protruding from the upper surface of the pedestal 43 is tightened with the nut 23 so that the pedestal 43 becomes the pier 20. It is fixed to the upper surface of the anchor seat 21. A mortar or the like (not shown) is filled between the lower surface of the cradle 43 and the upper surface of the seat 21 to eliminate a gap that may occur between them.

The lower first convex spherical surface 45b (sliding surface) of the sliding body 45 is rotatably housed in the first concave spherical surface 44a of the ball seat 44. The sliding body 45 has a second convex spherical surface 45a (sliding surface) having the same curvature as the second concave spherical surface 41c of the shoe 41 above the sliding body 45, and has the first convex spherical surface 45b described above below the second convex spherical surface 45a. There is. A friction material 46 is attached to the second convex spherical surface 45a.

Here, the friction material 46 is, for example, a friction material made of at least PTFE as a material. The friction material 46 is formed of a double woven fabric, and the double woven fabric is formed of PTFE fibers (polytetrafluoroethylene) and fibers having a higher tensile strength than PTFE fibers (high-strength fibers). Here, as "fiber having higher tensile strength than PTFE fiber", polyamide such as nylon 6.6, nylon 6, nylon 4.6, polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene na Examples include polyesters such as phthalate and fibers such as paraaramid. In addition, fibers such as metaalamide, polyethylene, polypropylene, glass, carbon, polyphenylene sulfide (PPS), LCP, polyimide, and PEEK can be mentioned. Further, heat-sealed fibers and fibers such as cotton and wool may be applied. Among them, PPS fibers having excellent chemical resistance and hydrolysis resistance and extremely high tensile strength are desirable.

The friction material 46 made of at least PTFE may be a woven material containing PTFE fibers other than the double woven fabric, a friction material made of only PTFE as a material, and a friction material made of a composite material of PTFE and another resin. , A friction material having a laminated structure of a friction material made of PTFE as a material and a friction material made of another resin as a material may be used.

As shown in FIGS. 2 and 4, the sliding body 45 is rotatably housed in the spherical seat 44 fixed to the upper surface of the pedestal 43, and the sliding body 45 is rotatably accommodated with respect to the friction material 46 at the top end of the sliding body 45. The friction 41 is arranged so that the mating material 42 fitted in the biconcave spherical surface 41c comes into contact with the mating material 42. In this state, the key portion 47b is loosely fitted into the left and right engaging grooves 41b of the shoe 41, and a pair of moving direction regulating jigs 47 having an inverted L-shaped cross section are attached to the pedestal 43 by a plurality of bolts 48. A sliding seismic isolation device 40 that is fixed and constitutes a movable bearing or a fixed bearing is formed. Here, the moving direction regulating jig 47 is also formed of the same material as the shoe 41 and the cradle 43.

As shown in FIG. 4, although there is a gap 41f having a length t1 in the vertical direction between the key portion 47b of the moving direction regulating jig 47 and the bottom surface of the engaging groove 41b of the shoe 41, for example, a large earthquake When the shoe 41 is lifted upward in the process of horizontal displacement at times, the key portion 47b above serves as a stopper, so that the shoe 41 supporting the superstructure is suppressed from being excessively lifted upward. ..

Returning to FIG. 1, the dustproof sheet 50 is attached to each of the pair of side surfaces 41j of the shoe 41 to which the movement direction regulating jig 47 is not attached.

The front view shape of the side surface 41j of the shoe 41 is a polygonal shape in which two rectangles having different widths and different widths are laminated because the engagement grooves 41b are provided on the left and right. In other words, the front view is horizontally long. The upper left and right corners of the rectangle are cut out in a rectangular shape. With respect to the dustproof sheet 50 attached to the side surface 41j, the upper 51, which is a region corresponding to the side surface 41j, has a shape complementary to the side surface 41j, and has notches 53 at the upper left and right ends, and the lower 52 thereof has notches 53. It extends to the cradle 43.

Here, as the dustproof sheet 50, a resin sheet typified by synthetic rubber such as EPDM (ethylene propylene diene rubber) and rubber such as natural rubber, and sheets of various materials such as fiber-based sheets, woven sheets, and non-woven fabrics are used. Applies.

A plurality of bolt holes 41k (three in the illustrated example) into which bolts 58 for attaching the dustproof sheet 50 are screwed are provided on the side surface 41j of the shoe 41. On the other hand, a plurality of (three in the illustrated example) through holes 54 are also provided above the dustproof sheet 50 at positions corresponding to the respective bolt holes 41k.

Further, on the outer side of the dustproof sheet 50, a pressing plate 55 for pressing and attaching the dustproof sheet 50 to the side surface 41j of the shoe 41 is arranged.

The front view shape (plan view shape) of the pressing plate 55 in the illustrated example is the same as the front view shape of the side surface 41j of the shoe 41, and the dustproof sheet 50 is provided with notches 56 at the upper left and right ends of the horizontally long rectangle. A plurality of through holes 57 (three in the illustrated example) are provided at positions corresponding to the through holes 54 provided in the above.

Here, the pressing plate 55 is formed of an iron plate, a stainless steel plate, a hard resin plate, or the like.

By disposing the dustproof sheet 50 and the pressing plate 55 on the side surface 41j of the shoe 41, inserting the bolt 58 into the corresponding through holes 57 and 54, and screwing the bolt 58 into the corresponding bolt hole 41k. , As shown in FIG. 2, the dustproof sheet 50 is attached to the side surface 41j of the shoe 41.

As shown in FIG. 2, the dustproof sheet 50 attached to the side surface 41j of the shoe 41 extends from the shoe 41 toward the cradle 43, and is 52 below the dustproof sheet 50 (a part of the dustproof sheet 50). Is in contact with the cradle 43 from the upper surface to the side surface.

As described above, in the slip seismic isolation device 40, the movement direction regulating jig 47 is provided on each side surface corresponding to the pair of end sides of the four corresponding end sides of the rectangular stile 41 and the cradle 43 in a plan view. A dustproof sheet 50 is disposed on each side surface 41j corresponding to the other pair of end edges, and the internal space 49 of the slip seismic isolation device 40 (sliding seismic isolation device 40) is provided by the movement direction regulating jig 47 and the dustproof sheet 50. (See FIG. 4) is blocked from the outside, so that high dust resistance is achieved.

As a result, dust and dirt floating on the outside enter the internal space 49 of the sliding seismic isolation device 40, and dust and the like adhere to the sliding surfaces 41c, 44a, 45a and 45b to design the sliding seismic isolation device 40. It is possible to prevent the friction coefficient of time from changing.

Further, since the dustproof sheet 50 is attached while being pressed by the pressing plate 55 having the same front view shape as the side surface 41j of the shoe 41, the connection strength of the attachment portion of the dustproof sheet 50 is enhanced. It is possible to suppress fluttering and peeling of the dustproof sheet 50 at the mounting portion.

On the other hand, the slip seismic isolation device 40A shown in FIG. 3 is a slip seismic isolation device in that the lower 52 of the dustproof sheet 50 not only contacts the pedestal 43 but is also fixed to the side surface of the pedestal 43 by bolts 59. Different from 40.

In the sliding seismic isolation device 40A, the dustproof sheet 50 is fixed to both the shoe 41 and the pedestal 43, but a horizontal load due to a predetermined seismic motion acts on the sliding seismic isolation device 40A, and the pedestal 43 is subjected to a horizontal load. When the shoe is relatively displaced (see, for example, FIG. 6), the dustproof sheet 50 is designed to break.

The predetermined seismic motion is, for example, a level 2 seismic motion or a level 3 seismic motion which is a maximum seismic motion. As a result, the internal space 49 between the displacement 41 and the cradle 43 is normally closed from the outside to have high dustproof properties, and the dustproof sheet 50 is broken when a predetermined earthquake motion acts. , It is possible to prevent the dustproof sheet 50 from obstructing the relative displacement between the cradle 43 and the sill 41. Here, a breaking line (not shown) may be provided at an intermediate position of the dustproof sheet 50 so that the dustproof sheet 50 breaks around the breaking line when a horizontal load is applied.

The front view shape and mounting form of the dustproof sheet are not limited to the illustrated examples, and there are various shapes and forms. Although not shown, for example, the dustproof sheet may be attached to the horizontally long rectangular area of the lower side 41j of the side surface 41j of the shoe 41 (hence, the form without a notch), and the pressing plate may be a shoe. The shape may be different from the front view shape of the side surface 41j of 41. Further, the dustproof sheet may be attached to the side surface to which the movement direction regulating jig is attached in addition to the side surface 41j of the shoe 41. Further, in the slip seismic isolation device having no moving direction regulating jig, for example, dustproof sheets are attached to all the side surfaces (four side surfaces) of the rectangular stile in a plan view, and the four dustproof sheets are used. The internal space of the slip seismic isolation device is blocked from the outside.

Next, an example of the seismic isolation bearing according to the embodiment will be described with reference to FIG.

For example, the seismic isolation bearing 60, which is a movable bearing, includes a pair of movement direction regulating jigs 47 fixed to the pedestal 43 in a state where the stile 41 can be moved in the direction of the bridge axis, and is a substructure of the bridge pier 20. On the upper surface of the seismic isolation seat 21 at the top end, the pair of movement direction regulating jigs 47 are arranged in the direction perpendicular to the bridge axis via the pedestal 43. When the pair of moving direction regulating jigs 47 are fixed to the shoe 41, the pair of moving direction regulating jigs 47 are arranged on the lower surface of the upper structure in the direction perpendicular to the bridge axis via the shoe 41. Will be.

The superstructure 10 is composed of a steel main girder 11 formed of I-shaped steel having upper and lower flanges and webs, and a steel cross girder 12 connecting the webs of the left and right main girders 11. .. Here, a reinforcing rib (not shown) may project from the web, and the reinforcing rib and the cross girder 12 may be bolted via a splice plate (not shown), or the main girder 11 may be bolted in the longitudinal direction thereof. Reinforcing ribs may be attached at intervals. Further, the superstructure 10 is not limited to the combination of the main girder 11 and the cross girder 12 made of I-shaped steel in the illustrated example, and may be formed of a main girder, a box girder, a concrete girder, or the like of a truss structure.

In the seismic isolation bearing 60, the shoe 41 is not fixed to the pair of moving direction regulating jigs 47, and the pair of moving direction regulating jigs 47 is used as a guide to allow the shoe 41 to move relative to the pedestal 43 in the bridge axis direction. Has been done. Therefore, when the upper structure 10 including the main girder 11 expands and contracts in the bridge axis direction due to a temperature change, the shoe 41 moves relative to the pedestal 43 in the bridge axis direction, whereby this upper structure It is possible to cope with expansion and contraction in the direction of the bridge axis of 10.

As shown in FIG. 5, the horizontal force during an earthquake can act on the seismic isolation bearing 60. In addition, the seismic isolation bearing 60 is above the seismic isolation bearing 60 due to the vertical seismic motion and the accompanying deflection vibration, and the overturning moment at the top of the pier 20 due to the center of gravity becoming an eccentric point such as a curved girder. Lift can act. In the seismic isolation bearing 60 shown, the key portion 47b of the pair of movement direction regulating jigs 47 having an inverted L-shaped cross section has a gap with respect to the engagement grooves 41b at the left and right ends of the shoe 41. Therefore, it is possible to suppress the risk that the stile 41 will be excessively lifted from the cradle 43 and fall off against the lift force that can act due to these various factors.

Next, with reference to FIG. 6, an example of the action of the slip seismic isolation device 40 when, for example, a level 2 earthquake or an earthquake larger than level 2 (an earthquake of an unexpected scale) acts in the direction of the bridge axis will be described. When a horizontal force during an earthquake acts in the opposite direction to the illustrated example, the horizontal displacement direction of the shoe 41 supporting the superstructure (not shown) and the rotation direction of the sliding body 45 are different from those shown in the illustrated example. Of course, the opposite is true.

First, when a horizontal force in the direction of the bridge axis due to a level 2 earthquake acts on the sliding seismic isolation device 40 that supports the superstructure, the sliding body 45 rotates and the stile 41 that supports the superstructure has a horizontal force. Horizontally displaced in the direction of action of. When a level 2 earthquake, which is the maximum possible earthquake, acts, the shoe 41 is lifted upward in the process of horizontal displacement in the direction of the bridge axis. Then, the vertical gap 41f (see FIG. 4) between the left and right engaging grooves 41b of the shoe 41 and the key portion 47b of the movement direction regulating jig 47 disappears, and both of them come into contact with each other. Lifting to is suppressed. When a horizontal force in the direction of the bridge axis due to a level 1 earthquake acts on the slip seismic isolation device 40, the horizontal displacement of the stile 41 does not occur to the extent that the gap 41f disappears.

On the other hand, when a horizontal force in the bridge axis direction due to an earthquake larger than level 2 acts in the same manner, the engaging groove 41b of the 沓 41 and the key portion 47b of the movement direction regulating jig 47 come into contact with each other, and the 沓 41 Lifting is suppressed. However, due to an earthquake larger than level 2, the engaging groove 41b of the upper bolt 41 pushes the key portion 47b of the moving direction regulating jig 47 upward due to an excessive horizontal force, so that the moving direction regulating jig 47 is received. The bolt fixed to the base 43 may be broken, the bolt may be pulled out, or the moving direction regulating jig 47 (for example, the key portion 47b) may be broken by plastic deformation or the like.

Then, as shown in FIG. 6, the shoe 41 can be further horizontally displaced in the X2 direction in the bridge axis direction, but since the stopper ring 41d is provided on the lower surface of the shoe 41, the sliding body 45 becomes the stopper ring 41d. It is possible to abut and suppress a further excessive horizontal displacement of the shoe 41.

Further, as is clear from FIG. 6, regarding the dustproof sheet 50 which hangs down from the cradle 41 and the lower portion 52 is in contact with the pedestal 43, the 沓 41 is displaced relative to the pedestal 43. There is no risk of being caught in the 41 or the cradle 43, and there are no problems such as deterioration of the performance and reliability of the slip seismic isolation device and fluctuation of the friction coefficient due to such involvement.

On the other hand, when a horizontal force in the direction perpendicular to the bridge axis due to a level 2 earthquake (which may include a level 1 earthquake) acts on the slip seismic isolation device 40 that supports the superstructure, the 沓 41 moves in the direction perpendicular to the bridge axis. Due to the horizontal displacement, the horizontal gap 41g (see FIG. 4) between the main body 47a of the moving direction regulating jig 47 and the outer peripheral surface of the 沓 41 disappears, and both of them come into contact with each other. Horizontal displacement is suppressed.

On the other hand, when a horizontal force in the direction perpendicular to the bridge axis due to an earthquake larger than level 2 acts in the same manner, the shackle 41 further pushes the movement direction regulating jig 47 in the direction perpendicular to the bridge axis to regulate the movement direction. The bolt fixed to the cradle 43 of the tool 47 may be broken, the bolt may be pulled out, or the moving direction regulating jig 47 may be plastically deformed.

Further, even when the stile 41 is displaced relative to the pedestal 43 in the direction perpendicular to the bridge axis, there is no possibility that the dustproof sheet 50 is entangled in the stile 41, the pedestal 43, etc. There are no problems such as deterioration of performance and reliability of the slip seismic isolation device due to this, and fluctuation of friction coefficient.

It should be noted that the configuration or the like described in the above embodiment may be another embodiment in which other components are combined, and the present invention is not limited to the configuration shown here. This point can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form thereof.

10: Upper structure 11: Main girder 12: Horizontal girder 20: Lower structure (pier)
21: Shoe seat 22: Anchor bolt 23: Nut 40, 40A: Sliding seismic isolation device 41: Slip (slip)
41a: Structure support surface 41b: Engagement groove 41c: Second concave spherical surface (sliding surface)
41d: Stopper ring 41f, 41g: Gap 41j: Side surface 41k: Bolt hole 42: Mating material 43: Lower shoe (cradle)
43a: Anchor bolt hole 43b: Bolt hole 44: Ball seat 44a: First concave spherical surface (sliding surface)
45: Sliding body 45a: Second convex spherical surface (sliding surface)
45b: First convex spherical surface (sliding surface)
46: Friction material 47: Movement direction regulation jig 47a: Main body 47b: Key 48: Bolt 49: Internal space 50: Dustproof sheet 51: Upper 52: Lower 53: Notch 54: Through hole 55: Pressing plate 56 : Notch 57: Through hole 58, 59: Bolt 60: Seismic isolation bearing

Claims (6)

A slip seismic isolation device installed between the upper structure of a building and the lower structure that is the foundation of the building.
A pedestal with a tee with a first concave spherical surface,
A sliding body having a first convex spherical surface accommodated in the first concave spherical surface and a second convex spherical surface on the opposite side of the first convex spherical surface.
With a shoe having a second concave spherical surface on which the second convex spherical surface slides,
A dustproof sheet is attached to the shoe, and a part of the dustproof sheet extending from the shoe toward the cradle is in contact with the cradle.
When the horizontal load due to the predetermined seismic motion is not applied, a part of the dustproof sheet is not fixed to the cradle but is in contact with it.
When a horizontal load due to a predetermined seismic motion is applied, a part of the dustproof sheet comes into contact without being fixed to the pedestal, and a part other than the part comes into contact without being fixed to the pedestal. A slip seismic isolation device that does not. A slip seismic isolation device installed between the upper structure of a building and the lower structure that is the foundation of the building.
A pedestal with a tee with a first concave spherical surface,
A sliding body having a first convex spherical surface accommodated in the first concave spherical surface and a second convex spherical surface on the opposite side of the first convex spherical surface.
With a shoe having a second concave spherical surface on which the second convex spherical surface slides,
A dustproof sheet is attached to the shoe, and a part of the dustproof sheet extending from the shoe toward the cradle is in contact with the cradle.
When the horizontal load due to the predetermined seismic motion is not applied, a part of the dustproof sheet is not fixed to the cradle but is in contact with it.
When a horizontal load due to a predetermined seismic motion is applied, a part of the dustproof sheet is not fixed to the pedestal and comes into contact with the dustproof sheet, and a part other than the part is not fixed to the pedestal. A slip seismic isolation device characterized by contact. A pedestal with a tee with a first concave spherical surface,
A sliding body having a first convex spherical surface accommodated in the first concave spherical surface and a second convex spherical surface on the opposite side of the first convex spherical surface.
With a shoe having a second concave spherical surface on which the second convex spherical surface slides,
A pair of movement direction regulating jigs straddling the shoe and the pedestal are fixed to either the shoe and the pedestal, and are not fixed to the other of the shoe and the pedestal. The horizontal displacement of the other shoe or cradle in a predetermined direction is regulated by the movement direction regulating jig.
The movement direction regulating jig includes a key portion, and the key portion is arranged at the end of the other shoe or cradle to regulate the vertical displacement of the other shoe or cradle.
The other shoe or pedestal is provided with a stopper ring that defines the sliding range of the sliding body, and a concave spherical and circular sliding surface inside the stopper ring.
A dustproof sheet is attached to the shoe, and a part of the dustproof sheet extending from the shoe toward the cradle is in contact with the cradle.
A slip seismic isolation device, characterized in that the dustproof sheet is attached to a side surface of the shoe where the movement direction regulating jig does not exist. The invention according to any one of claims 1 to 3, wherein a part of the dustproof sheet is attached to the side surface of the shoe in a pressed state via a pressing plate. Sliding seismic isolation device. The dustproof sheet is attached to both the shoe and the cradle.
3. The slip seismic isolation device according to claim 4. The slip seismic isolation device according to any one of claims 4 and 5, which is subordinate to claim 3 and claim 3, is installed on the abutment or pier of the bridge.
A seismic isolation bearing, characterized in that the pair of movement direction regulating jigs are arranged in a direction perpendicular to the bridge axis, and the dustproof sheet is attached to a pair of side surfaces of the shoe in the bridge axis direction.

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