JP2011246917A - Bearing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing structure capable of preventing an elastic body from separating when the elastic body is deformed in a vertically upward direction, and further attaining its downsizing.SOLUTION: A bearing structure comprises: a lower shoe 1 disposed on a lower structure 4; an upper shoe 2 disposed above the lower shoe 1 and supporting an upper structure 5; and an elastic body 3 interposed between and adhered to the lower shoe 1 and the upper shoe 2. In the bearing structure with a peripheral wall part 20 being provided on the outer periphery of the elastic body 3, a hollow part 22 adjacent to the outer periphery of the elastic body 3 is formed radially outside the elastic body 3, and at least a part of the hollow part 22 is formed on the peripheral wall part 20 and defined by an opposite face facing the outer periphery of the elastic body 3 with a space therebetween.

Description

  The present invention relates to a support structure interposed between a lower structure and an upper structure.

  Generally, in a bridge such as an elevated road, the main girder expands and contracts due to a change in environmental temperature and the like, and therefore a support structure capable of following a horizontal displacement is interposed between the pier and the main girder. As such a support structure, conventionally, for example, as shown in Patent Document 1 below, a lower gutter arranged on a lower structure such as a bridge pier, and an upper part such as a main girder arranged above the lower gutter. There has been proposed a structure including an upper collar supporting the structure and an elastic body interposed between the lower collar and the upper collar. A cylindrical or columnar (board-like) convex portion is projected on the upper surface of the lower collar, and a cylindrical peripheral wall portion surrounding the outer periphery of the convex section is suspended from the upper collar. The elastic body described above is disposed inside the peripheral wall portion. In such a support structure, since the elastic body is elastically deformed or the sliding structure using the sliding plate allows the lower heel and the upper heel to be relatively horizontally displaced, the main girder described above follows the expansion and contraction. Is possible.

  By the way, in bridges such as elevated roads, if an excessive load is applied to the main girder due to traffic congestion, the main girder bends and deforms, and the portion of the bearing structure that is near the center of the flexure is compressed vertically downward. The opposite portion may be pulled vertically upward. In this case, the elastic body may be peeled off from the lower eyelid or the upper eyelid due to the deformation in the vertical upward direction. Therefore, in the conventional bearing structure described above, the elastic body is compressed in the vertical direction in advance by the initial load (vertical load) input when the bearing structure is interposed between the lower structure and the upper structure. The elastic body is crushed and deformed. As a result, even if the support structure is deformed vertically upward due to the bending deformation of the main girder, if the elastic body is within the range of the amount of crushing deformation of the elastic body, the tensile force does not act on the elastic body. And peeling from the upper eyelid.

  In the conventional support structure described above, a plurality of through holes penetrating in the vertical direction are formed in the elastic body. As a result, when an initial load is input to the support structure, a part of the elastic body bulges inside the above-described through hole and the elastic body is crushed and deformed. The thickness (thickness) is reduced. And when the above-mentioned through-hole is obstruct | occluded with the elastic body, the place which an elastic body escapes disappears, and the crushing deformation of an elastic body is restrained. That is, the precompression amount of the elastic body is limited by the internal volume of the through hole.

JP 2009-79464 A

By the way, in the conventional bearing structure described above, an elastic body having a desired effective area is required in order to resist the tensile load in the vertical upward direction during an earthquake.
However, in the conventional bearing structure described above, since the effective area is lost by the amount of the through-hole formed in the elastic body, it is necessary to enlarge the effective diameter of the elastic body in order to secure a necessary effective area. As a result, there is a problem that the support structure is enlarged.

  The present invention has been made in consideration of the above-mentioned conventional problems, and an object of the present invention is to provide a support structure that can prevent the elastic body from being peeled off due to deformation in the vertically upward direction and can be downsized. It is said.

  A bearing structure according to the present invention is interposed between a lower rod disposed on a lower structure, an upper collar disposed above the lower collar and supporting the upper structure, and the lower collar and the upper collar. An elastic body bonded to each of the lower and upper collars, and a support structure in which a peripheral wall portion is provided around the outer periphery of the elastic body, and an outer peripheral surface of the elastic body on a radially outer side of the elastic body A hollow portion is formed, and at least a part of a wall surface defining the hollow portion is formed on the peripheral wall portion and faces the outer peripheral surface of the elastic body with a space therebetween. It is said.

  Because of this feature, a space (hollow part) is provided for the elastic body to escape when a vertical load is applied. Therefore, when an initial load (vertical load) is applied to the support structure, the outer peripheral surface of the elastic body Of these, the portion facing the hollow portion bulges inside the hollow portion and the elastic body is crushed and deformed, and the thickness (height) of the elastic body is reduced by the amount bulged into the hollow portion. As a result, even if a vertical upward deformation occurs, a tensile force does not act on the elastic body within the range of the reduced thickness of the elastic body (crush deformation amount). Is prevented from peeling off. In addition, the adhesive surface between the elastic body and the upper arm and the adhesive surface between the elastic body and the lower arm provide resistance to the tensile load in the vertical upward direction during an earthquake, but a hollow portion is formed in the elastic body. In addition, since the effective area of the elastic body that resists the tensile load in the vertically upward direction at the time of the earthquake is not lost, the above-described resistance force is sufficiently exhibited by the small-diameter elastic body.

  Further, since at least a part of the wall surface defining the hollow portion is formed to face the outer peripheral surface of the elastic body, the bulging deformation of the outer peripheral surface of the elastic body is restricted by this surface (opposing surface), and the elastic body is elastic. The amount of crushing deformation of the body is limited. That is, when an initial load is applied to the support structure and the outer peripheral surface of the elastic body bulges into the hollow portion, the bulging portion of the elastic body abuts against the above-described opposing surface, so that the bulging deformation of the bulging portion of the elastic body The amount of crushing deformation of the elastic body due to the initial load is adjusted.

In the support structure according to the present invention, it is preferable that a concave portion opened radially inward is formed on the inner peripheral surface of the peripheral wall portion, and the hollow portion is formed by the concave portion.
Thereby, the crushing deformation amount of the elastic body is adjusted with high accuracy. That is, after the initial load is applied to the support structure and the outer peripheral surface of the elastic body bulges into the hollow portion and comes into contact with the opposing surface, the bulged portion may further bulge in the vertical direction. Since the hollow portion is formed by the above, the above-described bulging in the vertical direction is stopped by the inner surface of the concave portion, and the crushing deformation of the elastic body is suppressed.

Moreover, as for the support structure which concerns on this invention, it is preferable that the said hollow part is formed over the perimeter along the outer peripheral surface of the said elastic body.
Thereby, the outer peripheral surface of the elastic body is easily swelled by the initial load applied to the support structure, and the elastic body is reliably crushed and deformed.

  According to the support structure of the present invention, the elastic body is crushed and deformed by a desired amount due to the initial load. Therefore, even if the support structure is deformed vertically upward, no tensile force acts on the elastic body. Can be prevented from peeling from the lower eyelid or upper eyelid. Moreover, since the hollow part is not formed in the elastic body and the effective area of the elastic body for resisting the tensile load in the vertical direction at the time of an earthquake is not lost, the effective diameter of the elastic body is increased. This is unnecessary, and the bearing structure can be downsized.

It is a half sectional view in plane view of a support structure for describing an embodiment of the present invention. It is a half sectional view in side view of the support structure for describing an embodiment of the present invention. It is a fragmentary longitudinal cross-sectional view of the support structure for describing embodiment of this invention. (A) is a longitudinal cross-sectional view schematically showing the support structure before the initial load is applied, and (b) is a vertical cross-sectional view schematically showing the support structure after the initial load is applied. . It is a fracture | rupture perspective view of the support structure for demonstrating the modification of this invention. It is a fracture | rupture perspective view of the support structure for demonstrating the modification of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a support structure according to the present invention will be described with reference to the drawings.
A chain line O shown in FIG. 2 indicates a central axis of the support structure, and is hereinafter referred to as “axis O”. A direction along the axis O is referred to as an “axial direction”, a direction orthogonal to the axis O is referred to as a “radial direction”, and a direction around the axis O is referred to as a “circumferential direction”. Further, the upper side in FIG. 2 is “upper”, and the lower side in FIG. 2 is “lower”.

  As shown in FIGS. 1 and 2, the support structure in the present embodiment is a support structure interposed between the upper end surface of a bridge pier 4 (lower structure) and the lower surface of a main girder 5 (upper structure). It is. The support structure includes a lower rod 1 fixed to the bridge pier 4, an upper rod 2 fixed to the main girder 5, and an elastic body 3 interposed between the lower rod 1 and the upper rod 2. Yes.

  The lower rod 1 is a flat steel member fixed to the upper end surface of the pier 4 by a plurality of (four in FIG. 1) anchor bolts 6. If it demonstrates in detail, the lower collar 1 is provided with the baseplate part 12 and the convex part 11 protrudingly provided by the upper surface of the baseplate part 12. As shown in FIG. The bottom plate portion 12 is a plate portion having a rectangular shape in plan view arranged perpendicular to the axis O, and bolt holes 10 through which the anchor bolts 6 are inserted are formed at the four corners of the bottom plate portion 12, respectively. Yes. The convex portion 11 is a disc-shaped convex portion disposed with the axis O as the central axis, and is disposed on the inner side of the peripheral wall portion 20 described later, and is locked to the peripheral wall portion 20 via the elastic body 3. It is a locking part.

  The upper rod 2 is disposed above the lower rod 1 and supports the main beam 5, and is a steel member that is fixed to the lower surface of the main beam 5 with bolts 7. More specifically, the upper collar 2 has a configuration in which a concave portion having a circular shape in plan view is formed on the lower surface thereof. As a schematic configuration, the top plate 21 and the outer edge of the top plate 21 are suspended downward. A peripheral wall portion 20. The top plate portion 21 is a plate portion having a circular shape in plan view disposed perpendicularly to the axis O, and is disposed above the convex portion 11 with a space therebetween. The peripheral wall portion 20 is a cylindrical wall portion extending over the entire periphery of the top plate portion 21 along the outer edge of the top plate portion 21, and is provided around the outer periphery of the elastic body 3 and has an axis O. Are arranged on the same axis as the convex portion 11. The inner diameter of the peripheral wall portion 20 is larger than the outer diameter of the convex portion 11, and a space is provided between the inner peripheral surface of the peripheral wall portion 20 and the outer peripheral surface of the convex portion 11. A sole plate 8 having a bolt hole (not shown) through which the bolt 7 is passed is interposed between the upper rod 2 fixed by the bolt 7 and the main beam 5.

  The elastic body 3 is an elastically deformable object made of rubber or a thermoplastic elastomer, and various known materials can be used. The elastic body 3 includes an elastic body main body 30 interposed between an upper end surface of the lower collar 1 (upper surface of the convex portion 11) and a lower end surface of the upper collar 2 (lower surface of the top plate portion 21), a convex The buffer part 31 interposed between the outer peripheral surface of the part 11 and the inner peripheral surface of the surrounding wall part 20 is provided. The elastic body main body 30 is a disk-shaped plate portion disposed perpendicular to the axis O, and the upper and lower surfaces of the elastic body main body 30 are on the upper surface of the convex portion 11 and the lower surface of the top plate portion 21. On the other hand, they are bonded by vulcanization molding. The buffer portion 31 is a cylindrical cylindrical portion that is suspended from the outer edge of the elastic body main body 30, and is provided around the entire circumference along the inner periphery of the peripheral wall portion 20. The inner and outer peripheral surfaces of the buffer portion 31 are bonded to the inner peripheral surface of the peripheral wall portion 20 and the outer peripheral surface of the convex portion 11 by vulcanization molding.

  As shown in FIG. 3, a hollow portion 22 adjacent to the outer peripheral surface of the elastic body 3 is formed on the radially outer side of the elastic body 3 described above. The hollow portion 22 is formed by a concave portion 23 formed on the inner peripheral surface of the peripheral wall portion 20 described above. The concave portion 23 is a groove portion that is U-shaped in the longitudinal sectional view and is opened in the radial direction and extends in the circumferential direction. The hollow portion 22 that is a space inside the concave portion 23 extends in the circumferential direction. Yes.

  More specifically, the recess 23 is formed between the upper wall surface 23a, the lower wall surface 23b opposite to the lower surface of the upper wall surface 23a, and the outer edge of the upper wall surface 23a and the outer edge of the lower wall surface 23b. And an opposing surface 23c facing the outer peripheral surface (the bulging surface 3a) with a gap in the radial direction. The upper wall surface 23 a is a planar wall surface formed along a virtual plane perpendicular to the axis O, and is formed flush with the lower surface of the top plate portion 21. The lower wall portion 23a is a flat wall surface formed along a virtual plane that is parallel to the upper wall surface 23a, that is, perpendicular to the axis O. The facing surface 23c is a wall surface perpendicular to the upper wall surface 23a and the lower wall surface 23b described above, and is formed in parallel to the outer peripheral surface (the bulging surface 3a) of the elastic body 3. The above-described hollow portion 22 is defined by the upper wall surface 23a, the lower wall surface 23b, the facing surface 23c, and the bulging surface 3a of the elastic body 3.

  Moreover, the hollow part 22 is formed over the perimeter along the outer peripheral surface (swelling surface 3a) of the elastic body 3, and is formed in planar view annular shape. Further, the hollow portion 22 is disposed at a height position corresponding to an elastic body main body 30 to be described later in the elastic body 3, and is disposed at a radially outer position of the upper end portion of the elastic body 3. Has been.

  Next, the operation of the support structure having the above-described configuration will be described.

  As shown in FIGS. 3A and 4A, when the main girder 5 is not installed on the support structure and a vertical load (initial load) is not applied to the support structure, the elastic body 3 The outer peripheral surface (the bulging surface 3a) is not bulged inside the hollow portion 22, and the hollow portion 22 (the inside of the recess 23) is hollow. At this time, a gap larger than at least a crushing deformation amount d described later is provided between the upper surface of the bottom plate portion 12 of the lower rod 1 and the lower end surface of the peripheral wall portion 20 of the upper rod 2.

  On the other hand, as shown in FIG. 3B and FIG. 4B, when the main girder 5 is installed on the support structure and a vertical load (initial load) is applied to the support structure, the hollow portion 22 causes the elastic body. Since the space for escaping 3 is secured, the upper part (bulging surface 3a) of the outer peripheral surface of the elastic body 3 bulges into the hollow portion 22, and the elastic body main body 30 is crushed and deformed accordingly. The thickness of the part 30 is reduced. Then, the position of the upper collar 2 sinks by the amount of deformation d of the elastic body 3, and the lower end surface of the peripheral wall portion 20 approaches or contacts the upper surface of the bottom plate portion 12 of the lower collar 1.

  At this time, since the facing surface 23c facing the bulging surface 3a of the elastic body 3 is formed as a part of the wall surface defining the hollow portion 22, the bulging deformation of the bulging surface 3a is regulated by the facing surface 23c. Thus, the amount of crushing deformation of the elastic body 3 is limited. That is, when an initial load is applied to the support structure and the bulging surface 3a of the elastic body 3 is bulged into the hollow portion 22, the bulging surface 3a comes into contact with the above-described facing surface 23c, so that the elastic body 3 The bulging of the bulging surface 3a is stopped, and the crushing deformation amount d of the elastic body 3 is adjusted.

  Moreover, since the hollow part 22 is formed by the recessed part 23 formed in the internal peripheral surface of the surrounding wall part 20, the bulging surface 3a of the elastic body 3 bulges in the hollow part 22, and contact | abuts to the said opposing surface 23c. Thereafter, the bulging portion of the bulging portion of the elastic body 3 in the vertical direction is stopped by the upper wall surface 23 a and the lower wall surface 23 b of the recess 23. Thereby, the crushing deformation of the elastic body 3 is reliably suppressed, and the crushing deformation amount of the elastic body 3 is adjusted with high accuracy.

  Further, since the hollow portion 22 (concave portion 23) described above is formed over the entire circumference along the outer peripheral surface of the elastic body 3, the bulging surface 3a of the elastic body 3 extends over the entire circumference. The bulging surface 3a of the elastic body 3 tends to bulge due to the initial load acting on the support structure, and the elastic body 3 is reliably crushed and deformed.

  Further, when the main girder 5 is bent and deformed, and the deformation in the vertical upward direction occurs in the portion of the support structure on the opposite side of the center side of the deformed branch, the upper rod 2 moves upward with respect to the lower rod 1. To do. At this time, as described above, since the elastic body 3 is crushed and deformed by the initial load in advance, the elastic body 3 can be deformed in the vertical direction as long as it is within the range of the crush deformation amount d. Tensile force does not work.

In addition, since the elastic body main body 30 of the elastic body 3 is bonded to the upper surface of the convex portion 11 of the lower rod 1 and the lower surface of the top plate portion 21 of the upper rod 2, the adhesive force causes the above-described earthquake at the time of the earthquake. Demonstrates resistance to tensile loads. Therefore, it is possible to expect a restriction on the tensile deformation in the vertically upward direction at the time of the earthquake by the resistance force.
At this time, since the hollow body or the like is not formed in the elastic body main body 30 and the effective area of the elastic body 3 that resists the tensile load in the vertical upward direction at the time of an earthquake is not lost, the elastic body The resistance force is sufficiently exerted by the small diameter elastic body 3 without increasing 3. Therefore, it is not necessary to increase the effective diameter of the elastic body 3, and the bearing structure can be downsized.

  When a horizontal displacement occurs between the bridge pier 4 and the main girder 5, the elastic body 3 of the elastic body 3 is shear-deformed in the horizontal direction and the buffer 31 of the elastic body 3 is crushed and deformed. The lower rod 1 and the upper rod 2 are relatively horizontally displaced. And the convex part 11 and the surrounding wall part 20 are mutually latched via the buffer part 31 of the elastic body 3, and a stopper function is exhibited, The said horizontal displacement is controlled. At this time, the shock at the time of engagement between the convex portion 11 and the peripheral wall portion 20 is reduced by the buffer portion 31 described above.

  According to the above-described support structure, the elastic body 3 is crushed and deformed by the initial load. Therefore, if the elastic body 3 falls within the range of the crushing deformation amount d, the elastic body 3 can be deformed even if it is deformed vertically upward. A tensile force does not act and it can prevent that the elastic body 3 peels from the lower eyelid 1 or the upper eyelid 2. FIG. Therefore, the main girder 5 is bent and deformed due to the passage of a large vehicle, etc. Even if the vertical deformation occurs in the portion of the support structure on the opposite side of the center side of the deformed branch, It can sufficiently follow the upward displacement.

  Further, a facing surface 23c facing the bulging surface 3a of the elastic body 3 is formed as a wall surface defining the hollow portion 22, and the bulging deformation of the bulging portion of the elastic body 3a is stopped by the facing surface 23c. Since the crushing deformation of the elastic body 3 is limited, the crushing deformation amount of the elastic body 3 due to the initial load can be adjusted. Thereby, the elastic body 3 can be crushed and deformed by a desired height, and the main girder 5 can be arranged at a predetermined height level.

  Moreover, the hollow part 22 is formed by the recessed part 23 formed in the internal peripheral surface of the surrounding wall part 20, and the swelling of the bulging part of the elastic body 3 to the up-down direction is carried out by the upper wall surface 23a and the lower wall surface 23b of the recessed part 23. Is stopped and the amount of crushing deformation of the elastic body 3 is adjusted with high accuracy, so that the main girder 5 can be accurately arranged at a desired height level.

  Further, the hollow portion 22 is formed over the entire circumference along the outer peripheral surface of the elastic body 3, and the bulging surface 3a of the elastic body 3 is easily bulged by the initial load, so that the elastic body 3 is reliably crushed and deformed. Therefore, peeling of the elastic body 3 from the lower eyelid 1 and the upper eyelid 2 can be reliably prevented.

  Further, since the buffer portion 31 of the elastic body 3 is also interposed between the outer peripheral surface of the convex portion 11 and the inner peripheral surface of the peripheral wall portion 20, the relative horizontal displacement between the lower rod 1 and the upper rod 2. A buffering function is exhibited. Thereby, horizontal force can be absorbed and horizontal displacement can be controlled well. Further, the buffer portion 31 is crushed and deformed with respect to the relative horizontal displacement between the lower rod 1 and the upper rod 2, so that it is possible to follow the horizontal displacement. Thereby, it is possible to cope with expansion and contraction of the main beam 5.

Although the embodiment of the support structure according to the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope of the present invention.
For example, in the above-described embodiment, the lower collar 1 is provided with the disk-shaped convex portion 11, and the upper collar 2 is provided with the peripheral wall portion 20 that is provided around the outer periphery of the convex portion 11. The invention may be configured such that a cylindrical (annular) convex portion is disposed inside the peripheral wall portion 20 instead of the disk-shaped convex portion 11.

  Further, the present invention may have a configuration in which a peripheral wall portion is provided on the lower collar 1 and a convex portion is provided on the upper collar 2. That is, a cylindrical peripheral wall portion is erected on the upper surface of the bottom plate portion 12 of the lower rod 1, and a convex portion that is inserted inside the peripheral wall portion is vertically disposed on the lower surface of the top plate portion 21 of the upper rod 2. It may be a configuration. In this case, the elastic body 3 is interposed between the upper surface of the bottom plate portion 12 and the lower end surface of the convex portion, and a concave portion 23 (hollow portion 22) is formed on the inner peripheral surface of the lower end portion of the peripheral wall portion.

  Moreover, the structure provided with the surrounding wall part separate from the lower arm and the upper arm may be sufficient as this invention. For example, as shown in FIG. 5, an upper collar 102 having the same diameter as that of the projection 11 is disposed above the projection 11 of the lower collar 1, and the lower surface of the upper collar 102 and the upper end surface of the projection 11 The elastic body 103 may be interposed between them, and the cylindrical body 120 (peripheral wall portion) may be provided around the outer periphery of the upper collar 102, the elastic body 103, and the convex portion 11. The cylinder 120 described above is a separate member from the lower rod 1 and the upper rod 102, and is a highly rigid cylinder having a height from the lower rod 1 (convex portion 11) to the upper rod 102. The cylindrical body 120 is mounted on the outer periphery of the convex portion 11, the elastic body 103, and the upper collar 102 by forming the elastic body 103 between the convex section 11 and the upper collar 102 and then covering it from above the upper collar 102. Is done. Further, a concave portion 123 extending in the circumferential direction is formed in a portion corresponding to the elastic body 103 in the inner peripheral surface of the cylindrical body 120 described above, and a hollow portion 122 is formed by the concave portion 123.

  Further, the present invention may have a configuration in which a laminated body composed of an elastic body and a rigid plate is interposed between a lower collar and an upper collar. For example, as shown in FIG. 6, a plurality of elastic layers 203 (elastic body) and steel plate layers 209 are alternately stacked between the upper end surface of the convex portion 11 of the lower rod 1 and the lower end surface of the upper rod 102. Alternatively, the laminated body 200 may be interposed. The cylindrical body 120 described above is provided around the outer periphery of the laminated body 200, the convex portion 11, and the upper collar 102. Of the inner peripheral surface of the cylindrical body 120, a portion corresponding to the laminated body 200 is provided. A recess 223 extending in the circumferential direction is formed, and the hollow 222 is formed by the recess 223. In addition, it is also possible to form a recess for each elastic layer 203 on the inner peripheral surface of the cylinder 120. That is, the structure which formed in the axial direction the some recessed part which adjoins each elastic layer 203 intermittently in the internal peripheral surface of the cylinder 120 may be sufficient.

  In the above-described embodiment, the bulging surface 3a of the elastic body 3 and the facing surface 23c of the hollow portion 22 are formed in parallel. However, in the present invention, the facing surface of the hollow portion 22 is the bulging surface of the elastic body 3. It may be inclined with respect to the exit surface 3a, and the opposing surface of the hollow portion 22 may be a curved surface having a curved shape in longitudinal section.

  Further, in the above-described embodiment, the annular recess 23 is formed on the inner peripheral surface of the peripheral wall portion 20 so as to extend over the entire circumference, and the hollow portion 22 is formed by the recess 23. The hollow part in the invention is not limited to the configuration described above. For example, the recess 23 does not have to be extended over the entire circumference, and a hollow portion is formed by a plurality of recesses divided in the circumferential direction, or a hollow portion is formed by a C-shaped recess in plan view. May be. Further, a hollow portion may be formed by other than the concave portion 23, and the elastic body 3 is formed with a gap between the outer peripheral surface and the inner peripheral surface of the peripheral wall portion 20, and this gap is not a hollow portion. May be.

Further, in the above-described embodiment, the lower gutter 1 is directly arranged on the pier 4 and the main girder 5 is supported on the upper gutter 2 via the sole plate 8. The lower rod 1 may be disposed on the pier 4 via an intermediate member such as a plate, and the upper rod 2 may directly support the main girder 5.
In the present invention, the upper surface of the upper rod 2 is provided with a sliding material for relatively displacing the upper rod 2 and the upper structure such as the main girder 5 in the horizontal direction, or the lower surface of the lower rod 1. Further, a configuration may be provided in which a sliding material is provided for relatively displacing the lower arm 1 and the lower structure such as the pier 4 in the horizontal direction.

  In the above-described embodiment, the upper and lower surfaces of the elastic body main body 30 of the elastic body 3 are formed by vulcanization molding on the upper surface of the convex portion 11 of the lower rod 1 and the lower surface of the top plate portion 21 of the upper rod 2. Each elastic body is bonded, but the elastic body in the present invention may be bonded to the lower iron 1 or the upper iron 2 by a method other than the above-described bonding by vulcanization molding. 1 or upper collar 2 may be adhered.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

1 Lower rod 2, 102 Upper rod 3, 103, 203 Elastic body 4 Bridge pier (lower structure)
5 Main girder (superstructure)
20 peripheral wall 120 cylinder (peripheral wall)
22, 122, 222 Hollow part 23, 123, 223 Recess 23c Opposing surface

Claims (3)

A lower arm disposed on the lower structure, an upper arm disposed above the lower arm and supporting the upper structure, and interposed between the lower arm and the upper arm, respectively on the lower arm and the upper arm A bonded elastic body,
In a support structure in which a peripheral wall portion is provided around the outer periphery of the elastic body,
On the radially outer side of the elastic body, a hollow portion adjacent to the outer peripheral surface of the elastic body is formed,
At least a part of the hollow portion is defined by an opposing surface that is formed on the peripheral wall portion and faces the outer peripheral surface of the elastic body with a space therebetween. In the bearing structure according to claim 1,
A support structure in which a concave portion opened radially inward is formed on an inner peripheral surface of the peripheral wall portion, and the hollow portion is defined by the concave portion. In the support structure according to claim 1 or 2,
The support structure according to claim 1, wherein the hollow portion is formed over the entire circumference along the outer peripheral surface of the elastic body.

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