JP2022010974A - Sliding seismic isolation device and bridge - Google Patents

Abstract

To provide a sliding seismic isolation device, which can suppress relative horizontal displacement and vertical displacement between an upper shoe and a lower shoe during an earthquake, and a bridge having the sliding seismic isolation device on a movable bearing.SOLUTION: A sliding seismic isolation device 40 has an upper shoe 41, a lower shoe 43, and a sliding body 45. A pair of movement direction restricting jigs 47 disposed across the upper shoe 41 and the lower shoe 43 are fixed to either one of the upper shoe and the lower shoe and are not fixed to the other shoe. Horizontal displacement of the other shoe in a predetermined direction is restricted by the movement direction restricting jigs 47. The movement direction restriction jigs 47 have a key part 47b. Vertical displacement of the other shoe is restricted by disposing the key part 47b on a top face or an undersurface of an end of the other shoe. A stopper ring 41d for restricting sliding range of the sliding body 45 and a first sliding surface 41c, which has concave spherical shape and is circular in planar view and located inside the stopper ring 41d, are disposed on the undersurface or the top face of the other shoe.SELECTED DRAWING: Figure 3

Description

The present invention relates to a bridge provided with a slip seismic isolation device and a slip seismic isolation device.

In Japan, which is an earthquake-prone country, various earthquake-resistant structures such as buildings, bridges, elevated roads, and detached houses have various seismic resistance, such as technology to resist seismic force and technology to reduce seismic force entering the structure. Technology, seismic isolation technology and vibration control technology have been developed and applied to various structures. Above all, the seismic isolation technology is a technology for reducing the seismic force itself entering the structure, so that 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-plugged 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 has a flat sliding seismic isolation bearing and a spherical sliding seismic isolation bearing. The flat sliding seismic isolation bearing does not have a restoring force, but the spherical sliding seismic isolation bearing has a restoring force and an earthquake. Has a self-centering function of time. Here, to explain the configuration by taking an example of a spherical sliding seismic isolation bearing, the upper and lower stiles having a sliding surface having a curvature and the upper and lower stiles arranged between the upper and lower stiles are respectively. It is composed of a sliding body (slider) having an upper surface and a lower surface that are in contact with the sliding surface of the sill and have the same curvature as each shoe, and this type of sliding seismic isolation device is a double concave seismic isolation device. It is also called (slip seismic isolation device for two-sided sliding bearings). Further, as another form, for example, there is a sliding seismic isolation device in which a sliding body is fixed to the upper sill and the upper sill and the sliding body slide with respect to the lower sill. It is also called a single concave type seismic isolation device (slip seismic isolation device with single-sided sliding bearings).

By the way, the scale (level) of an earthquake includes Level 1 where the probability of occurrence is high but the damage is small and medium-sized, and Level 2 where the probability of occurrence is not high but there is a possibility of major damage. In addition, recently, it is assumed that an earthquake larger than Level 2 which has an extremely low probability of occurring but may cause great damage is expected. Level 1 and Level 2 earthquakes correspond to medium and large earthquakes, respectively, and although there are no design standards for earthquakes larger than Level 2, they are the largest set when considering the worst. It is positioned as the earthquake level of. Hereinafter, in the present specification, an earthquake larger than level 2 may be referred to as a large earthquake, and an earthquake of both a level 2 earthquake and an earthquake larger than level 2 may be referred to as a large earthquake.

If the slip seismic isolation device is designed assuming up to level 1 earthquake, the level 2 earthquake will be an unexpected earthquake, and if the slip seismic isolation device is designed assuming up to level 2 earthquake, the level An earthquake larger than 2 is an unexpected earthquake, but when an unexpected earthquake occurs in this way, the amount of horizontal relative displacement between the lower structure and the upper structure is the limit deformation in the conventional slip seismic isolation device. May exceed the amount. When the relative displacement amount between the lower structure and the upper structure exceeds the limit deformation amount, there is a risk that, for example, the upper sill and the upper structure may fall off from the lower sill, or the upper structure may fall off from the upper sill. In response to such a problem, in the event of an unexpected earthquake, the sliding body slides on the sliding surface, and the lower and upper sill are largely displaced in the horizontal direction, forming a ring shape on the lower or upper sill. A slip support has been proposed that regulates further relative displacement between the lower sill and the upper sill by abutting the stopper from the outside in the horizontal direction (see, for example, Patent Document 1).

JP 2015-209730A

According to the sliding bearing described in Patent Document 1, when an unexpected earthquake occurs, the amount of horizontal relative displacement between the lower and upper bearings can be regulated by a stopper, so that the sliding bearing is fail-safe. A function can be added, and excessive horizontal displacement of the lower structure and the upper structure can be suppressed, and the upper structure can be eliminated from falling off from the upper bearing.

Here, Patent Document 1 describes an embodiment in which the slip bearing is provided between a pier (lower structure) and a bridge girder (upper structure) of a plate girder bridge. This description example shows an example of movement in the direction perpendicular to the bridge axis, but in general, there are fixed bearings that absorb only the rotation of the superstructure and movable bearings that absorb the rotation and expansion and contraction of the superstructure. Movable bearings and fixed bearings are installed in each of a plurality of piers (including abutments) arranged apart from each other in the direction, and bridge girders are supported by each bearing. With this configuration, the movable bearing responds to expansion and contraction in the bridge axis direction due to temperature changes and live load of the superstructure including the main girder, while the combination of fixed bearing and movable bearing allows the bridge to be in constant service. Performance is guaranteed.

By the way, in the event of an earthquake, a horizontal force and an upward lift act on the superstructure supported by the upper sill, and the superstructure is displaced horizontally by the horizontal force and upward due to the lift. Can be. However, although Patent Document 1 describes, for example, a ring-shaped stopper that provides a fail-safe function against excessive horizontal displacement of the upper sill, there is no disclosure of a means for suppressing upward displacement (lifting) due to the lifting force. Therefore, it is difficult to suppress both the horizontal displacement and the vertical displacement of the upper sill during an earthquake.

The present invention has been made in view of the above problems, and is a slip seismic isolation device capable of suppressing both the relative horizontal displacement and the vertical displacement between the upper and lower bearings at the time of an earthquake, and this slip seismic isolation device. The purpose is to provide a bridge with the device in a movable bearing.

In order to achieve the above object, one aspect of the slip seismic isolation device according to the present invention is
A slip seismic isolation device having an upper sill and a lower sill and a sliding body slidable between the upper sill and the lower sill.
A pair of moving direction regulating jigs straddling the upper shoe and the lower shoe are fixed to one of the upper shoe and the lower shoe, and to the upper shoe or the other shoe of the lower shoe. The horizontal displacement of the other shoe in a predetermined direction is regulated by the movement direction regulating jig.
The movement direction regulating jig is provided with a key portion, and the key portion is arranged on the upper surface or the lower surface of the end portion of the other shoe to regulate the vertical displacement of the other shoe.
On the lower surface or the upper surface of the other shoe, a stopper ring that defines the sliding range of the sliding body and a concave spherical and circular first sliding surface inside the stopper ring shall be provided. It is characterized by.

According to this aspect, a pair of moving direction regulating jigs are fixed to either one of the upper and lower stiles, and a pair of moving direction regulating jigs are attached to either of the upper and lower stiles. Since it is not fixed and can be freely displaced (moved) in the horizontal direction using the pair of movement direction regulating jigs as a guide, it is possible to move in a predetermined direction among the horizontal relative movements of the upper and lower sill. It can be regulated (restricted). This aspect can be applied to any structure such as a bridge, an elevated road, and a house, but when this aspect is applied to a movable bearing of a bridge, the above-mentioned "predetermined direction" is, for example, a bridge axis. The direction perpendicular to the bridge axis is an example. For example, the movement of the upper bearing in the direction perpendicular to the bridge axis is permitted, 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), for example, it is permissible to freely horizontally displace the upper sill in the direction of the bridge axis with respect to the lower sill.

Further, in this embodiment, the movement direction regulating jig is provided with a key portion, and the upper surface (upper surface of the upper shoe) or the lower surface (lower surface of the lower shoe) of the end portion of the other shoe to which the movement direction regulating jig is not fixed is provided. By disposing the key portion on the seat, the vertical displacement (vertical displacement) of the other shoe can be regulated. Therefore, for example, when a lifting force caused by a level 2 or higher earthquake (a level 2 earthquake and an earthquake larger than level 2) acts on the upper shoe, the upper shoe comes into contact with the key portion of the movement direction regulating jig and is moved upward. It is possible to suppress the lifting of the shoe (an example of vertical displacement). By suppressing the floating of the upper sill, it is possible to prevent the upper sill 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 first sliding surface on which the sliding body slides in the other shoe to which the moving direction regulating jig is not fixed. Due to this stopper ring, when a horizontal force due to an unexpected earthquake (such as when an earthquake larger than level 2 acts when assuming a level 2 earthquake) acts on the upper sill, for example, the upper sill is 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 to which the movement direction regulating jig is not fixed, and this columnar shape can be mentioned. A curved first sliding surface is provided inside the stopper ring of the groove. Further, as another example of the stopper ring, among the other shoes, there is a form consisting of a ring-shaped protrusion provided on the surface on which the sliding body slides, and the inside of the ring-shaped protrusion has a curved shape. A first 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 upper and lower stiles, and the other of the upper and lower stiles (first). A stopper ring, which is a second fail-safe mechanism, is provided for the shoe) to which the fail-safe mechanism is not fixed. With these configurations, while the movement direction in the horizontal plane of the 沓 where the movement direction regulation jig is not fixed is regulated by the movement direction regulation jig, the vertical displacement such as lifting due to the lifting force is regulated by the movement direction regulation jig. It can be suppressed, and further, excessive horizontal displacement of the stile that is not fixed with the movement direction regulating jig and is provided with the stopper ring can be suppressed by the sliding body coming into contact with the stopper ring. can.

Further, in another aspect of the slip seismic isolation device according to the present invention, an engaging groove in which the key portion is arranged is provided at the end portion of the other shoe.
At least a vertical gap is provided between the engaging groove and the key portion.
The sliding body has a convex spherical second sliding surface, and the sliding body has a convex spherical second sliding surface.
When the first sliding surface of the other shoe slides on the second sliding surface, the gap is eliminated and the engaging groove engages with the key portion. ..

According to this aspect, the key portion of the moving direction regulating jig has a vertical gap with respect to the engaging groove at the end of the other stile to which the moving direction regulating jig is not fixed. Arranged, for example, when the other sword (for example, the upper sword) slides on the sliding body during an earthquake and the gap is eliminated according to the sliding of the other sword, the engaging groove becomes the key part. By engaging, excessive lifting of the upper sill is suppressed by the movement direction regulating jig fixed to the lower sill.

That is, at all times or in the event of a small earthquake such as a level 1 earthquake, the vertical gap between the engagement groove and the key is maintained and the two do not engage. In addition, as a design concept, the assumed earthquake is up to level 2 earthquake, and the length of the gap is set so that the vertical gap is eliminated and the engagement groove and the key part are engaged in the case of the largest assumed earthquake. Can be set. Further, even when the engagement groove and the key portion are engaged due to the largest assumed earthquake, the wall surface of the stopper ring provided by the other shoe sliding on the convex spherical second sliding surface of the sliding body. The length of the gap and the position of the stopper ring may be set so that the sliding body does not reach. Here, "at least a vertical gap is provided" means that there is a horizontal gap in addition to the vertical gap between the engaging groove and the key portion. Includes.

Further, in another aspect of the slip seismic isolation device according to the present invention, a friction material is attached to the second sliding surface.
A mating material having a circular shape in a plan view is attached to the first sliding surface.
The mating material has a diameter equal to or larger than the length of an arc passing through the center of the first sliding surface in the stopper ring, and the mating material is fitted in the stopper ring. The mating material is characterized in that it has a compressive force in the radial direction in the stopper ring.

According to this aspect, the other shackle (eg, the upper shackle) to which the movement direction regulating jig is not fixed has a diameter equal to or larger than the length of the arc passing through the center of the first sliding surface in the stopper ring. The mating material is provided with the mating material, and the mating material is deformed into a curved shape and fitted in the stopper ring. In this fitted state, the mating material is elastically deformed and contracted, and a compressive force is applied in the radial direction thereof. Will be in a state of having. Since the mating material is fitted into the stopper ring in a state where the mating material has a compressive force in the radial direction, the reaction force of the compressive force in the radial direction acts on the inner peripheral surface of the stopper ring, and the reaction force is applied to the stopper ring. The mating material is firmly attached. Further, since the mating material can be attached in close contact with the first sliding surface, no adhesive or the like is required when attaching the mating material to the first sliding surface. In principle, this "elastic deformation" means that the mating material is completely elastically deformed, but it also includes a state in which plastic deformation is slightly advanced in addition to elastic deformation.

Here, the mating material is, for example, a stainless steel mating material, and the thickness of the mating material can be set to 1 mm or more. When the thickness of the mating material made of stainless steel is 1 mm or more, it is possible to suppress wrinkles that may occur on the mating material when the mating material is elastically deformed into a curved shape and fitted into the first sliding surface. Further, even in the process in which the sliding body repeatedly slides along the mating material fitted to the first sliding surface after the sliding seismic isolation device is put into service, wrinkles that may occur on the mating material can be suppressed.

To give one design example, when the diameter of the first sliding surface is 2000 mm and the radius of curvature is 2500 mm, the diameter of the mating material is 2057 mm, and therefore the mating material is larger than the diameter of the inner circumference of the stopper ring having a diameter of 2000 mm. The diameter of is set to be 57 mm larger. When the diameter of the first sliding surface is 500 mm and the radius of curvature is 4500 mm, the diameter of the mating material is 500.25 mm, and the diameter of the mating material is 0.25 mm rather than the diameter of the inner circumference of the stopper ring having a diameter of 500 mm. It is set large. A compressive force acts in the radial direction on the mating material that is deformed into a curved shape and is fitted into the stopper ring in a plan view, and the reaction force acts on the inner peripheral surface of the stopper ring. Therefore, the mating material can be firmly attached to the stopper ring by deforming the mating material into a curved shape and fitting it into the stopper ring.

Here, the inner wall surface of the stopper ring may be a vertical wall surface, a tapered wall surface, or a wall surface in which a vertical surface and a tapered surface are combined. Here, for example, in the sliding seismic isolation device of the present embodiment for forming a single-sided sliding seismic isolation device, the shoe to which the mating material is fitted is either an upper shoe or a lower shoe.

Further, in another aspect of the slip seismic isolation device according to the present invention, the moving direction regulating jig is fixed to one of the shoes with bolts, and has one of the following two configurations. Is what you have
(1) The breaking strength of the bolt is set so that the bolt breaks when a horizontal force larger than the horizontal force for eliminating the gap acts on the slip seismic isolation device. When the sliding body is broken, the sliding body does not reach the stopper ring, the bolt is broken, and the sliding body further slides so that the sliding body reaches the stopper ring.
(2) When a horizontal force larger than the horizontal force for eliminating the gap acts on the slip seismic isolation device, the movement direction regulation control is performed so that at least a part of the movement direction regulation jig is broken. When the tool is configured and at least a part of the moving direction regulating jig is broken, the sliding body does not reach the stopper ring, and at least a part of the moving direction regulating jig is broken. As the sliding body further slides, the sliding body reaches the stopper ring.

According to this aspect, for example, when an earthquake up to level 2 is assumed and an earthquake larger than level 2 is larger than that, with respect to the convex spherical second sliding surface of the sliding body. As a result of the concave spherical first sliding surface of the other shoe (for example, the upper shoe) further slides, for example, the upper shoe is lifted upward and the gap between the engagement groove and the key portion is eliminated (to zero). Will be). Then, as the upper sill moves further, the bolt fixing the moving direction regulating jig breaks, or a part of the moving direction regulating jig (for example, the key part) breaks, and as a result, the moving direction regulating jig is controlled. The tool can be disengaged from the lower sill, the restraint of the upper sill by the movement direction regulating jig can be released, and the horizontal displacement of the upper sill in the horizontal direction of 360 degrees is allowed. Even at this stage, the sliding body has not reached the wall surface of the stopper ring. Then, due to the horizontal force at the time of the earthquake, the upper sill is further horizontally displaced with respect to the sliding body, but when the horizontally displaced sliding body reaches the inner wall of the stopper ring, the upper sill is further horizontally displaced. (Excessive horizontal displacement) is suppressed. In this way, the plane dimension of the first sliding surface (or the distance from the center of the first sliding surface to the stopper ring), the plane dimension of the second sliding surface of the sliding body, the breaking strength of the bolt, etc. By appropriately setting according to the assumed earthquake and the unexpected earthquake, it is guaranteed to suppress the horizontal displacement such as the upper sill and the suppression of the lift in the case of the assumed earthquake such as the level 2 earthquake. Further, it is guaranteed to suppress excessive horizontal displacement such as a shoe shoe in the event of an unexpected earthquake larger than level 2.

Further, one aspect of the bridge according to the present invention is
The slip seismic isolation device and
The slip seismic isolation device has an upper structure and a lower structure intervening as movable bearings.
The pair of facing movement direction regulating jigs are arranged in the direction perpendicular to the bridge axis of the lower structure or the upper structure.

According to this aspect, by forming a movable bearing by the slip seismic isolation device of the present invention, for example, suppression of horizontal displacement such as a bridge at all times or in the event of an assumed earthquake and suppression of lifting are guaranteed, and further, unexpected. It is guaranteed to suppress excessive horizontal displacement such as bearings in the event of an earthquake, and it is possible to provide a bridge that can exhibit sufficient vibration damping performance against earthquakes of all sizes.

As can be understood from the above explanation, according to the slip seismic isolation device and the bridge of the present invention, both the relative horizontal displacement and the vertical displacement between the upper and lower stiles at the time of an earthquake can be suppressed.

It is a side view of an example of a bridge which concerns on embodiment. It is a perspective view which shows the state which an example of the slip seismic isolation device which concerns on embodiment is fixed to the top end of a pier. FIG. 2 is a vertical cross-sectional view of an example of a sliding seismic isolation device fixed to the top end of a pier, which is a view taken along the line III-III in FIG. It is an exploded perspective view of an example of the slip seismic isolation device which concerns on embodiment. FIG. 5 is a vertical cross-sectional view of a state in which the slip seismic isolation device according to the embodiment is interposed between the upper structure and the lower structure as a movable bearing as viewed from the direction of the bridge axis. It is a schematic diagram which saw from the bridge axis direction the state which the movement direction regulation jig suppresses the lifting of the upper sill when the horizontal force acts on the slide seismic isolation device which concerns on embodiment. .. A schematic diagram of a state in which the stopper ring suppresses excessive horizontal displacement of the upper sill when a horizontal force is applied to the slip seismic isolation device according to the embodiment in the direction perpendicular to the bridge axis. be. A schematic diagram of a state in which the stopper ring suppresses excessive horizontal displacement of the upper sill when a horizontal force acts on the slip seismic isolation device according to the embodiment in the direction perpendicular to the bridge axis from the direction of the bridge axis. be. It is a perspective view explaining an example of the manufacturing method of the upper sill which constitutes the slip seismic isolation device which concerns on embodiment. It is a vertical sectional view explaining an example of the manufacturing method of the upper sill which constitutes the slip seismic isolation device which concerns on embodiment. Following FIG. 9, it is a perspective view explaining an example of the manufacturing method of the upper sill which constitutes the slip seismic isolation device. Following FIG. 11, it is a vertical cross-sectional view illustrating an example of a method of manufacturing an upper shoe that constitutes a slip seismic isolation device, and shows a state in which the mating material is gradually pushed along the inner peripheral surface of the stopper ring. It is a figure which shows both. It is a perspective view of an example of the upper stool which constitutes the slip seismic isolation device which concerns on embodiment, and is the figure which shows the state which the compressive force acts in the radial direction of the mating material.

Hereinafter, the bridge according to the embodiment and the slip seismic isolation device according to the embodiment for forming the movable bearing of the bridge will be described with reference to the attached drawings together with the manufacturing method of the upper sill that constitutes the slip seismic isolation device. In the present specification and the drawings, substantially the same components may be designated by the same reference numerals to omit duplicate explanations.

[Bridge and sliding seismic isolation device according to the embodiment]
First, an example of a bridge according to an embodiment and an example of a slip seismic isolation device according to an embodiment will be described with reference to FIGS. 1 to 8. Here, FIG. 1 is a side view of an example of a bridge according to an embodiment. Further, FIG. 2 is a perspective view showing a state in which an example of the sliding seismic isolation device according to the embodiment is fixed to the top end of the pier, and FIG. 3 is a view taken along the line III-III of FIG. It is a vertical sectional view of an example of a sliding seismic isolation device fixed to the top end of a pier, and FIG. 4 is an exploded perspective view of an example of a sliding seismic isolation device according to an embodiment. Further, FIG. 5 is a vertical cross-sectional view of a state in which the slip seismic isolation device according to the embodiment is interposed between the upper structure and the lower structure as a movable bearing in the direction of the bridge axis.

As shown in FIG. 1, the bridge 100 is a sliding seismic isolation device 30 which is 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 via a sliding seismic isolation device 40 which is a movable bearing. In the illustrated example, one continuous superstructure 10 is supported by five piers 20, and a fixed bearing 30 is arranged at the top end of one of the five piers 20. The movable bearings 40 are arranged at the top ends of the other four piers 20, but the number of piers 20 supporting one superstructure 10 and the number of fixed bearings 30 and the like are various.

As shown in FIGS. 2 to 4, the slip seismic isolation device 40 forming the movable bearing of the bridge 100 includes an upper shoe 41 (an example of the other shoe), a lower shoe 43 (an example of one shoe), and a lower one. It is a one-sided sliding bearing slip seismic isolation device having a sliding body 45 that is rotatable with respect to the shoe 43, and the upper shoe 41 is configured to be slidable 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, and the lower sill 43 is provided with respect to the sliding body 45. It may be a sliding seismic isolation device having a single-sided sliding bearing that is slidably configured.

Both the upper sill 41 and the lower sill 43 are formed of rolled steel material for welded steel (SM490A, B, C, or SN490B, C, or S45C), SUS material, cast steel material, cast iron, etc., and have different planar dimensions from each other. It has a rectangular shape in a plan view. In the illustrated example, the plane dimension of the lower shoe 43 is relatively large.

The upper surface of the upper sill 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 lower shoe 43, two moving direction regulating jigs 47 including a block-shaped main body portion 47a and a key portion 47b protruding toward the upper 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. 3, there is a gap between the engaging groove 41b of the upper sill 41 and the key portion 47b of the moving direction regulating jig 47, and there is a gap between the lower surface of the key portion 47b and the bottom surface of the engaging groove 41b. A gap 41f having a length t1 in the vertical direction is provided between them, and a gap 41g having a length t2 in the horizontal direction is provided between the main body portion 47a and the outer peripheral surface of the upper sill 41. As shown in FIG. 3, at all times, the pair of left and right movement direction regulating jigs 47 and the upper shoe 41 are completely trimmed with gaps 41f and 41g from each other, and therefore, as shown in FIG. In addition, the upper shoe 41 that supports the upper structure (not shown) is movable in the direction of the bridge axis.

On the other hand, as shown in FIGS. 3 and 4, a stopper ring 41d formed of a columnar groove is provided on the lower surface of the upper shoe 41, and a curved first sliding surface is provided inside the stopper ring 41d. 41c is provided. A mating material 42 (sliding plate) made of stainless steel and having a circular shape in a plan view is fitted to the first sliding 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 dimension of the stopper ring 41d and the first sliding surface 41c, and the mating material 42 having a relatively large plan-viewing dimension passes through the stopper ring 41d. By being fitted into one sliding 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 cause the first sliding. The mating material 42 is firmly fixed to the surface 41c. The production method will be described in detail below.

As shown in FIG. 4, a ball seat 44 provided with a concave spherical surface 44a is fixed to the upper surface of the lower shoe 43 by a plurality of bolts 49, and the ball seat 44 is detachably fixed to the lower shoe 43. It is a cradle. Here, the ball seat 44 is also made of the same material as the upper shoe 41 and the lower shoe 43.

Further, as shown in FIG. 4, the lower shoe 43 has a plurality of anchor bolt holes 43a through which a plurality of anchor bolts 22 (see FIGS. 2 and 3) projecting upward from the top end of the pier 20 are inserted. A plurality of bolt holes 43b corresponding to the plurality of bolt holes 47c of the moving direction regulating jig 47 are provided. As shown in FIGS. 2 and 3, the anchor bolt 22 is inserted into the anchor bolt hole 43a of the lower pier 43, and the anchor bolt 22 protruding from the upper surface of the lower pier 43 is tightened with the nut 23 to form the lower pier 43. It is fixed to the upper surface of the foot seat 21 of the bridge pier 20. It should be noted that a mortar or the like (not shown) is filled between the lower surface of the lower shoe 43 and the upper surface of the shoe seat 21, and a gap that may occur between them is eliminated.

The concave spherical surface 44a of the ball seat 44 rotatably accommodates the lower convex spherical surface 45b of the sliding body 45. The sliding body 45 has a second sliding surface 45a having the same curvature as the first sliding surface 41c of the upper shoe 41 above the sliding body 45, and has the above-mentioned convex spherical surface 45b below the second sliding surface 45a. A friction material 46 is attached to the second sliding 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, "fibers having higher tensile strength than PTFE fibers" include polyamides such as nylon 6.6, nylon 6, nylon 4.6, polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene na. Examples include polyester such as phthalate and fiber such as paraaramid. Further, 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 material, 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 and a friction material made of another resin may be used.

As shown in FIGS. 2 to 4, the sliding body 45 is rotatably housed in the ball seat 44 fixed to the upper surface of the lower shoe 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 upper sill 41 is arranged so that the mating material 42 fitted to the sliding surface 41c comes into contact with the sliding surface 41c. In this state, the key portion 47b is loosely fitted into the left and right engaging grooves 41b of the upper sill 41, and a pair of moving direction regulating jigs 47 having an inverted L-shaped cross-sectional view is provided by a plurality of bolts 48 to the lower sill 43. A slip seismic isolation device 40 that is fixed to and constitutes a movable bearing is formed. Here, the moving direction regulating jig 47 is also formed of the same material as the upper shoe 41 and the lower shoe 43. Although not shown, the fixed bearing shown in FIG. 1 has, for example, a configuration in which the key portion 47b of the moving direction regulating jig 47 shown in FIG. 2 and the engaging groove 41b of the upper sill 41 are fixed by bolts. This configuration restricts the movement of the upper bearing in the direction of the bridge axis at all times.

As shown in FIG. 3, 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 upper sill 41, for example, it is large. When the upper sill 41 is lifted upward in the process of horizontal displacement during an earthquake, the upper key portion 47b acts as a stopper, so that the upper sill 41 that supports the superstructure is excessively lifted upward. It is suppressed.

As shown in FIG. 5, in the movable bearing 40, the pair of movement direction regulating jigs 47 fixed to the lower shoe 43 in a state where the upper shoe 41 can be moved in the direction of the bridge axis is the bridge pier 20 which is a lower structure. It is arranged in the direction perpendicular to the bridge axis via the lower sill 43 on the upper surface of the sill 21 at the top end. The pair of moving direction regulating jigs 47 may be fixed to the upper stile 41. In this form, the pair of moving direction regulating jigs 47 have the upper stile 41 on the lower surface of the upper structure. It is arranged in the direction perpendicular to the bridge axis.

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. Reinforcing ribs (not shown) may project from the web, and the reinforcing ribs and the cross girder 12 may be bolted to each other via a splice plate (not shown), and 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 movable bearing 40, the upper shoe 41 is not fixed to the pair of movement direction regulating jigs 47, and the pair of moving direction regulating jigs 47 is used as a guide to move the upper shoe 41 relative to the lower shoe 43 in the bridge axis direction. It is allowed. 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 upper sill 41 moves relative to the lower sill 43 in the bridge axis direction, thereby causing this upper structure. It is possible to cope with the expansion and contraction of the body 10 in the direction of the bridge axis.

As shown in FIG. 5, a horizontal force during an earthquake can act on the movable bearing 40. In addition, the movable bearing 40 has lift due to the vertical seismic motion and the accompanying deflection vibration, and the overturning moment at the top of the pier 20 caused by the center of gravity becoming an eccentric point, for example, as in a curved girder. Can work. In the movable bearing 40 shown in the figure, 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 upper shoe 41. Since it is arranged in such a state that the upper sill 41 is excessively lifted from the lower sill 43 against the upper lift force that can act due to these various factors, it is possible to suppress the risk of the upper sill 41 falling off. ..

Next, with reference to FIGS. 6 and 7, 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. An example of the operation of the slip seismic isolation device 40 when an earthquake larger than, for example, level 2 acts in the direction perpendicular to the bridge axis will be described with reference to FIG. Here, FIG. 6 shows a state in which the movement direction regulating jig suppresses the lifting of the upper sill when a horizontal force is applied in the bridge axis direction to the slip seismic isolation device according to the embodiment in the bridge axis direction. FIG. 7 is a schematic view seen from the above, and FIG. 7 is a state in which the stopper ring suppresses the excessive horizontal displacement of the upper sill when a horizontal force is similarly applied in the direction of the bridge axis, as viewed from the direction perpendicular to the bridge axis. It is a schematic diagram. Further, FIG. 8 shows a schematic view from the bridge axis direction in which the stopper ring suppresses excessive horizontal displacement of the upper sill when a horizontal force acts on the slip seismic isolation device in the direction perpendicular to the bridge axis. It is a figure. When a horizontal force during an earthquake acts in the direction opposite to the illustrated example, the horizontal displacement direction of the upper stile 41 supporting the superstructure (not shown) and the rotation direction of the sliding body 45 are as shown in the illustrated example. Of course, is the opposite.

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 upper stile 41 that supports the superstructure is horizontal. Horizontal displacement in the direction of force action. When a level 2 earthquake, which is the maximum assumed earthquake, occurs, as shown in FIG. 6, the upper shoe 41 is lifted upward in the X1 direction in the process of horizontal displacement in the bridge axis direction. Then, the vertical gap 41f (see FIG. 3) between the left and right engaging grooves 41b of the upper sill 41 and the key portion 47b of the moving direction regulating jig 47 disappears, and both of them come into contact with each other. The upward rise of the 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 upper sill 41 does not occur to the extent that the gap 41f disappears.

On the other hand, when the horizontal force in the bridge axis direction due to the earthquake larger than level 2 acts in the same manner, as shown in FIG. 6, the engaging groove 41b of the upper sill 41 and the key portion 47b of the moving direction regulating jig 47 Contact, and the lifting of the upper sill 41 is suppressed. However, due to an earthquake larger than level 2, the engaging groove 41b of the upper sill 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 lowered. The bolt fixed to the stile 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. 7, the upper shoe 41 may be further horizontally displaced in the X2 direction in the bridge axis direction, but the sliding body 45 is a stopper ring because the stopper ring 41d is provided on the lower surface of the upper shoe 41. It abuts on 41d and can suppress further excessive horizontal displacement of the upper shoe 41.

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 upper sill 41 is in the direction perpendicular to the bridge axis. Due to the horizontal displacement, the horizontal gap 41g (see FIG. 3) between the main body 47a of the moving direction regulating jig 47 and the outer peripheral surface of the upper sill 41 disappears, and both of them come into contact with each other. Further 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 upper squeeze 41 further pushes the moving direction regulating jig 47 in the direction perpendicular to the bridge axis to regulate the moving direction. The bolt fixing the jig 47 to the lower sill 43 may be broken, the bolt may be pulled out, or the moving direction regulating jig 47 may be broken by plastic deformation or the like.

Then, as shown in FIG. 8, the upper shoe 41 may be further horizontally displaced in the X3 direction in the direction perpendicular to the bridge axis, but the sliding body 45 is a stopper due to the stopper ring 41d provided on the lower surface of the upper shoe 41. It abuts on the ring 41d and can suppress further excessive horizontal displacement of the upper shoe 41.

In this way, by having the slip seismic isolation device 40 having the movement direction regulating jig 47, it is possible to effectively suppress the excessive lifting of the upper shoe 41 in the event of a large earthquake such as a level 2 earthquake. Can be done. Further, since the slip seismic isolation device 40 has the stopper ring 41d, it is possible to effectively suppress the excessive horizontal displacement of the upper shoe 41 in the event of an unexpected large earthquake such as an earthquake larger than level 2. .. That is, since the slip seismic isolation device 40 has two types of fail-safe mechanisms, it is possible to suppress both excessive vertical displacement (particularly floating) and excessive horizontal displacement, and of course, for an assumed earthquake. In addition, it is possible to guarantee the vibration damping performance of the bearing even in the event of an earthquake of an unexpected scale.

[Example of how to make the upper sword]
Next, with reference to FIGS. 9 to 13, an example of a method for manufacturing the upper sill that constitutes the slip seismic isolation device forming the movable bearing 40 will be described. Here, FIGS. 9, 11, and 12 are perspective views illustrating, in order, an example of a method of manufacturing a shoe shoe constituting the slip seismic isolation device according to the embodiment. Further, FIG. 10 is a vertical cross-sectional view illustrating an example of a method of manufacturing the upper stile that constitutes the slip seismic isolation device according to the embodiment, and FIG. 13 is a vertical sectional view illustrating the upper stile that constitutes the slip seismic isolation device according to the embodiment. It is a perspective view of one example, and is the figure which shows the state which the compressive force acts on the mating material in the radial direction together.

As shown in FIG. 9, the upper shoe 41 constituting the slip seismic isolation device 40 (see FIGS. 2 to 4) has a shoe body provided with a concave spherical first sliding surface 41c and a first sliding surface 41c. It has a mating material 42 (sliding plate) to be installed. The mating material 42 is a mating material of the friction material 46 attached to the convex spherical second sliding surface 45a of the sliding body 45 (see FIGS. 3 and 4).

On one wide surface of the upper shoe 41, a stopper ring 41d formed of a circular and cylindrical groove in a plan view that defines the sliding range of the sliding body is provided, and inside the stopper ring 41d, a circular shape in a plan view is provided. The first sliding surface 41c is provided.

The mating material 42 is made of a stainless steel material (SUS material) and has a thickness of 1 mm or more. Since the thickness of the mating material 42 made of stainless steel is 1 mm or more, as described below, when the mating material 42 is elastically deformed into a curved shape and fitted into the first sliding surface 41c, wrinkles are formed on the mating material 42. Can be suppressed. Further, even in the process in which the sliding body 45 repeatedly slides along the mating material 42 fitted to the first sliding surface 41c after the sliding seismic isolation device 40 is put into service, wrinkles are suppressed from being generated on the mating material 42. can.

As is clearly shown in FIG. 10, a notch 41e continuous in the circumferential direction is provided at the base of the bottom of the stopper ring 41d (the interface with the first sliding surface 41c).

As shown in FIGS. 9 and 10, the mating material 42 having a circular shape in a plan view has a diameter larger than the diameter of the inner circumference of the stopper ring 41d, and more specifically, the first slide in the stopper ring 41d. It has a diameter L2 (diameter passing through the center O2 of the mating material 42) having a length L1 or more of an arc passing through the center O1 on the moving surface 41c. Here, the length L2 is set to be the same as the length L1 or slightly longer than the length L1. More specifically, when the mating material 42 is elastically deformed in a curved shape and fitted into the stopper ring 41d, the mating material 42 is elastically deformed and contracted, but the length is within this elastic deformation range. The length L2 of the diameter is set longer than the length L1 by the amount.

In the method of manufacturing the upper sill, as described above, a mating material 42 having a diameter of L2 having a length L1 or more of an arc passing through the center O1 in the first sliding surface 41c in the stopper ring 41d is prepared, and the mating material 42 is prepared. The material 42 is placed in the Y1 direction with respect to the stopper ring 41d, and both are aligned concentrically.

Next, as shown in FIG. 11, the mating material 42 placed on the stopper ring 41d is pressed toward the first sliding surface 41c in the Y2 direction by the pressing jig 50.

Here, as shown in FIGS. 11 and 12, the pressing jig 50 is provided with a plurality of pressing pieces 52 having a pressing surface 53 having the same curvature as the first sliding surface 41c, radially centered on the central shaft 51. It is a linear body. Although not shown, a surface material having the same curvature as the first sliding surface 41c may be attached to the surface of the plurality of pressing pieces 52. Further, as another form of the pressing jig, a hollow or solid block body having the same curvature as the first sliding surface may be used.

As shown in FIG. 12, when the mating material 42 is pressed in the Y2 direction by the pressing jig 50, the mating material 42 is elastically deformed in a curved shape along the stopper ring 41d, and the root of the stopper ring 41d is cut. It fits into the notch 41e. By pressing the pressing jig 50 with a pressing force of, for example, about 5t (≈50kN) to 10t (≈100kN), the mating material 42 can be elastically deformed into a curved shape and fitted into the stopper ring 41d.

As shown in FIG. 13, in a state where the mating material 42 is elastically deformed in a curved shape and fitted into the stopper ring 41d to form an upper sill, a compressive force Q1 acts on the mating material 42 in the radial direction thereof. is doing. Then, due to this radial compression force Q1, a reaction force Q2 on the outer side in the radial direction is generated and acts on the inner peripheral surface of the stopper ring 41d (the inner peripheral surface of the notch 41e), and elastically deforms in the stopper ring 41d in a curved manner. The mating material 42 is firmly attached by this reaction force Q2. At this time, the end portion of the mating material 42 is fitted into the notch 41e continuous in the circumferential direction provided at the base of the inner peripheral surface of the stopper ring 41d, so that the mating material 42 deformed into a curve is on the outside. It is possible to prevent the stopper ring 41d from engaging and disengaging in an attempt to swell and return to its original position.

In addition to the form in which the notch is provided as shown in the illustrated example, the stopper ring is located at a position below the inner peripheral surface of the stopper ring (a position slightly above the first sliding surface 41c) in the circumferential direction of the stopper ring. A plurality of bolts may be attached at intervals so as to project inward in the radial direction. In this embodiment, the mating material is locked to the plurality of bolts, so that the mating material can be prevented from engaging and disengaging from the stopper ring. Further, the stopper ring 41d may be in a form in which a notch or the like is not provided at the base of the inner peripheral surface of the stopper ring 41d.

In this way, the mating material 42 is pressed against the first sliding surface 41c by the pressing jig 50, the mating material 42 is elastically deformed into a curved shape, and the mating material 42 is fitted into the stopper ring 41d. You can make a jig. Then, by applying a pressing jig 50 having a plurality of pressing pieces 52 having a pressing surface 53 having the same curvature as the first sliding surface 41c in a radial manner, the pressing jig 50 having a simple structure can be used as a flat surface. The entire surface of the mating material 42 having a circular shape can be pressed as uniformly and efficiently as possible against the first sliding surface 41c of the shoe body of the upper shoe 41.

In addition, the form opposite to the illustrated example, that is, the ball seat is fixed to the lower surface of the upper shoe, the stopper ring is provided on the upper surface of the lower shoe, and the first sliding surface is provided inside the stopper ring. In the form, the lower sill is manufactured by fitting the mating material into the stopper ring of the lower sack by the manufacturing method shown in FIGS. 9 to 13.

[Design example of the first sliding surface of the shoe and the mating material]
Next, a design example of the first sliding surface of the shoe and the mating material fitted in the first sliding surface will be described. When the radius of curvature of the first sliding surface of the arc is 4500 mm, the diameter of the projected surface of the first sliding surface (the length of the chord with respect to the spherical surface of the first sliding surface) is 669 mm, which is the length of the first sliding surface. The arc length (the length of the arc passing through the center of the first sliding surface of the circular shape in a plan view) is 670.6 mm. The distance between the center of the first sliding surface (center of the arc) and the center of the projection surface (depth of the center of the first sliding surface) is 12.47 mm.

On the other hand, the present inventors model a mating material having a diameter of 670.6 mm in a computer, and have a radius of 0.8 mm in the radial direction on the outer circumference of the mating material until the diameter reaches 669.0 mm. An analysis was performed to apply forced displacement.

As a result of the analysis, it was found that the mating material model was elastically deformed in a curved shape, and its center was displaced by 14.96 mm in the vertical direction. It has been verified that the first sliding surface is in close contact with the sliding surface while applying pressure.

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: Cross girder 20: Lower structure (pier)
21: Shoe seat 22: Anchor bolt 23: Nut 30: Sliding seismic isolation device (fixed bearing)
40: Sliding seismic isolation device (movable bearing)
41: Upper shoe (the other shoe)
41a: Structure support surface 41b: Engagement groove 41c: First sliding surface 41d: Stopper ring 41e: Fitting groove 41f, 41g: Gap 42: Mating material 43: Lower sill (one sill)
43a: Anchor bolt hole 43b: Bolt hole 44: Ball seat 44a: Concave spherical surface 45: Sliding body 45a: Second sliding surface 45b: Convex spherical surface 46: Friction material 47: Movement direction regulating jig 47a: Main body 47b: Key Parts 48, 49: Bolt 50: Pushing jig 51: Central shaft 52: Pushing piece 53: Pushing surface 100: Bridge O1: Center of first sliding surface O2: Center of mating material L1: Arc of first sliding surface Length L2: Diameter of mating material Q1: Compressive force in the radial direction Q2: Reaction force

Claims (5)

A slip seismic isolation device having an upper sill and a lower sill and a sliding body slidable between the upper sill and the lower sill.
A pair of moving direction regulating jigs straddling the upper shoe and the lower shoe are fixed to one of the upper shoe and the lower shoe, and to the upper shoe or the other shoe of the lower shoe. The horizontal displacement of the other shoe in a predetermined direction is regulated by the movement direction regulating jig.
The movement direction regulating jig is provided with a key portion, and the key portion is arranged on the upper surface or the lower surface of the end portion of the other shoe to regulate the vertical displacement of the other shoe.
On the lower surface or the upper surface of the other shoe, a stopper ring that defines the sliding range of the sliding body and a concave spherical and circular first sliding surface inside the stopper ring shall be provided. A slip seismic isolation device featuring. An engaging groove in which the key portion is arranged is provided at the end of the other shoe.
At least a vertical gap is provided between the engaging groove and the key portion.
The sliding body has a convex spherical second sliding surface, and the sliding body has a convex spherical second sliding surface.
When the first sliding surface of the other shoe slides on the second sliding surface, the gap is eliminated and the engaging groove engages with the key portion. , The slip seismic isolation device according to claim 1. A friction material is attached to the second sliding surface, and a friction material is attached.
A mating material having a circular shape in a plan view is attached to the first sliding surface.
The mating material has a diameter equal to or larger than the length of an arc passing through the center of the first sliding surface in the stopper ring, and the mating material is fitted in the stopper ring. The slip seismic isolation device according to claim 2, wherein the mating material has a compressive force in the radial direction in the stopper ring. The movement direction regulating jig is fixed to one of the shoes with bolts.
The slip seismic isolation device according to claim 3, further comprising any of the following two types of configurations.
(1) The breaking strength of the bolt is set so that the bolt breaks when a horizontal force larger than the horizontal force for eliminating the gap acts on the slip seismic isolation device. When the sliding body is broken, the sliding body does not reach the stopper ring, the bolt is broken, and the sliding body further slides so that the sliding body reaches the stopper ring.
(2) When a horizontal force larger than the horizontal force for eliminating the gap acts on the slip seismic isolation device, the movement direction regulation control is performed so that at least a part of the movement direction regulation jig is broken. When the tool is configured and at least a part of the moving direction regulating jig is broken, the sliding body does not reach the stopper ring, and at least a part of the moving direction regulating jig is broken. As the sliding body further slides, the sliding body reaches the stopper ring. The slip seismic isolation device according to any one of claims 1 to 4.
The slip seismic isolation device has an upper structure and a lower structure intervening as movable bearings.
A bridge, characterized in that a pair of facing movement direction regulating jigs are arranged in a direction perpendicular to a bridge axis of the lower structure or the upper structure.

Images