JP2012031687A - Elastic bearing for bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic bearing for a bridge, capable of reducing a surface strain of an elastic body only by providing a protrusion on the elastic body.SOLUTION: An elastic bearing for a bridge, which includes: an elastic support portion 21 that comprises a plurality of reinforcing plates 23 disposed at intervals and an elastic body 22 for covering the respective reinforcing plates 23; a bridge girder coupling plate 24 for coupling the elastic body 22 to the side of a bridge girder 2; and a bridge pier coupling plate 25 for coupling the elastic body 22 to a bridge pier 3, reduces a deformation force applied to the bridge pier 3 from the bridge girder 2. Since protrusions 26 protruding outward are provided on the side of the bridge girder coupling plate 24 and the side of the bridge pier coupling plate 25, respectively, a crack and a wrinkle formed on the sides of the coupling plates 24 and 25 can be reduced.

Description

  The present invention relates to an elastic bearing for a high-damping bridge provided between a bridge girder and a pier.

  As this type of elastic bearing for bridges, the one shown in FIG. 10 is generally known. The bridge elastic support 1 is disposed between the bridge girder 2 and the pier 3 and is subjected to strain applied from the bridge girder 2 to the pier 3, that is, the direction of the bridge axis of the bridge girder 2 according to the change in the outside air temperature (bidirectional in FIG. 10). The shearing force to the arrow), the shearing force in the horizontal direction including the direction perpendicular to the bridge axis direction due to wind, etc. are attenuated.

  The bridge elastic support 1 has a structure in which a sole plate 11, an upper collar 12, an elastic support portion 13, a lower collar 14, and a base plate 15 are sequentially arranged. Further, the upper surface of the elastic support portion 13 is connected to the bridge girder 2 via the sole plate 11 and the upper heel 12, while the lower surface of the elastic support portion 13 is connected to the pier 3 via the lower ridge 14 and the base plate 15, thereby The elastic support portion 13 is integrally connected to the bridge girder 2 and the pier 3.

  The elastic support portion 13 has a plurality of reinforcing plates 13a arranged at intervals and an elastic body 13b covering each of the reinforcing plates 13a, and the strain applied from the bridge girder 2 is absorbed by the elastic force of the elastic body 13b. Yes. The elastic body 13b is composed of rubber inner elastic bodies 13c alternately laminated and vulcanized and bonded to the reinforcing plates 13a, and rubber side walls bonded and vulcanized so as to cover the outer peripheral surfaces of the inner elastic bodies 13c and the reinforcing plates 13a. The side elastic body 13d protects the internal elastic body 13c from the external environment and prevents the internal elastic body 13c from being deteriorated (such as cracks).

  However, in this elastic bearing for bridge, although the internal elastic body 13c is protected by the side wall elastic body 13d, cracks and wrinkles are formed in the side wall elastic body 13d, and the appearance of the elastic bearing for bridge is not only damaged, but remains. There was a risk of local destruction due to distortion.

  In order to solve such problems, the applicant has proposed an elastic bearing described in Japanese Patent Application Laid-Open No. 2009-243652 (Patent Document 1). The elastic bearing described in Patent Document 1 is composed of an inner and outer two layers of a side wall elastic body, and the inner layer is formed of a rubber material giving priority to elongation at break while the outer layer is made of a rubber material giving priority to hardness. . This reduces the shearing force in the inner layer, while preventing the occurrence of cracks and the like in the outer layer.

  The applicant has also proposed an elastic bearing described in Japanese Patent Laid-Open No. 2000-1820 (Patent Document 2) in order to solve the above-mentioned problem. The elastic bearing described in Patent Document 2 uses a reinforcing rubber having a large shear elastic modulus at the peripheral edge of the internal elastic body adjacent to the bridge girder or the pier among the internal elastic bodies alternately laminated with the reinforcing plate, The structure prevents the internal elastic body from cracking.

JP2009-233652 JP2000-1820

  However, in the elastic support of Patent Document 1, it is necessary to prepare two types of elastic bodies as the side wall elastic bodies, and not only the material cost is high, but also when the side wall elastic bodies are bonded to the internal elastic bodies, the internal elasticity There is a problem that the manufacturing process becomes complicated, such as arranging two types of elastic bodies outside the body.

  Moreover, in the elastic support of the said patent document 2, it is necessary to prepare this and two types of elastic bodies as an internal elastic body, and similarly to patent document 1, the cost of a material and the complexity of a manufacturing process will be caused. It was.

  An object of the present invention is to provide an elastic bearing for a bridge that can reduce the surface distortion of the elastic body only by forming a protruding portion on the elastic body in view of the conventional problems.

  In order to solve the above-mentioned problems, the invention of claim 1 is directed to a plurality of reinforcing plates arranged at intervals and an elastic support portion formed of an elastic body covering each of the reinforcing plates, and the elastic body on the bridge girder side. In the elastic support for bridges, which has a bridge girder connection plate that connects to the bridge pier and a bridge pier connection plate that connects the elastic body to the pier, the elastic body is on the bridge girder connection plate side and the pier connection plate side. It has the structure which has the protrusion part which protrudes outward.

  According to the first aspect of the present invention, even if a horizontal shearing deformation force is applied from the bridge girder to the elastic support portion, the bridge girder connection plate side and the pier connection plate side have the protruding portions protruding outward, so that these connection Cracks and wrinkles generated on the plate side can be reduced.

  The protruding portion may be formed on the side wall elastic body as in the invention of claim 2 or may be formed by protruding the internal elastic body as in the invention of claim 3.

  According to a fourth aspect of the present invention, in the elastic bearing for a bridge according to the first to third aspects, the projecting portion has a structure having at least a side surface orthogonal to the bridge axis direction among the side surfaces of the elastic support.

  In general, distortion caused by changes in the outside air temperature is generated particularly in the direction of the bridge axis. Therefore, it is necessary to form the distortion at least on the side surface perpendicular to the direction of the bridge axis.

  According to a fifth aspect of the present invention, in the elastic bearing for a bridge according to the first to fourth aspects, the elastic body on the side of each reinforcing plate is formed thinner as the distance from the bridge girder connection plate and the bridge pier connection plate increases.

  Of the shear stress applied to the elastic body, the vicinity of each connection plate is large, and the shear stress is reduced as the distance from each connection plate increases. Therefore, the thickness dimension of the elastic body on the side of each reinforcing plate may be designed according to the shear stress applied to each part.

  According to the present invention, since the surface distortion of the elastic body can be reduced only by forming the protruding portion on the elastic body, an extremely simple shear force damping structure is obtained.

Cross-sectional view in the direction of the bridge axis of the elastic bearing for bridges according to the first embodiment The principal part expanded sectional view of 1st Embodiment Cross-sectional view in the direction of the bridge axis showing the deformation state of the elastic bearing for bridges according to the first embodiment Sectional drawing which shows the amount of distortion deformation corresponding to the thickness dimension of a protrusion part Sectional view showing surface strain analysis by FEM model Bridge axis direction sectional view in which a part of the bridge elastic bearing according to the second embodiment is omitted. Cross-sectional view in the direction of the bridge axis of the elastic bearing for bridges according to the third embodiment Cross section in the direction of the bridge axis of the elastic bearing for bridges according to the fourth embodiment Cross-sectional view in the direction of the bridge axis of the elastic bearing for bridges according to the fifth embodiment Cross-sectional view in the axial direction of a conventional elastic bearing for bridges

  FIGS. 1 to 3 show an elastic bearing for a bridge according to the present invention. FIG. 1 is a cross-sectional view of the elastic bearing for a bridge according to the first embodiment, and FIG. 2 is an enlarged view of a main part of the first embodiment. Sectional drawing and FIG. 3 are bridge axial direction sectional drawings which show the deformation | transformation state of the elastic bearing for bridges concerning 1st Embodiment. The same components as those of the conventional example shown in FIG. 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The bridge elastic bearing 20 according to the present embodiment is arranged between the bridge girder 2 and the bridge pier 3 in the same manner as in the conventional example, and the structure of the bridge elastic bearing 20 is higher than the bridge girder 2 in the same manner as in the conventional example. A sole plate 11, an upper rod 12, an elastic support portion 21, a lower rod 14 and a base plate 15 are sequentially arranged toward the lower pier 3. Further, the sole plate 11 and the upper rod 12 connected to the upper surface of the elastic support portion 21 are connected to the bridge girder 2 by bolts 16a and 16b, while the lower rod 14 and the base plate 15 connected to the lower surface of the elastic support portion 21 are bolts 16c and 16b. The elastic support portion 21 connects the bridge girder 2 and the pier 3 by connecting to the pier 3 by 16d.

  The elastic support 20 for bridges according to the present embodiment is characterized by the structure of the elastic support part 21 and does not have a characteristic structure as described above, and the structure of the elastic support part 21 will be described in detail below.

  The elastic support portion 21 is formed in a rectangular parallelepiped shape as a whole, for example, an elastic body 22 that reduces a shearing force transmitted from the bridge girder 2 to the pier 3, and a plurality of steel reinforcing plates 23 that are arranged at intervals in the vertical direction. And a steel bridge girder connection plate 24 disposed on the upper portion of the elastic body 22 and a steel bridge pier connection plate 25 disposed on the lower portion of the elastic body 22.

  Here, the bridge girder connection plate 24 is connected to the upper bridge 12 via the bolt 16e, while the pier connection plate 25 is connected to the lower bridge 14 via the bolt 16f, whereby the elastic body 22 is connected to the bridge girder. It is connected to the bridge girder 2 side via the plate 24 and connected to the pier 3 side via the pier connection plate 25.

  The elastic body 22 has an internal elastic body 22a formed by alternately laminating with the reinforcing plates 23, and the internal elastic body 22a attenuates the shearing force transmitted from the bridge girder 2 or the pier 3 side. As the material of the internal elastic body 22a, a material suitable for absorbing a shearing force, that is, a high damping rubber already proposed by the applicant in Patent Document 1 or the like is used. Examples thereof include natural rubber (NR), isoprene rubber (IR), styrene butadiene copolymer rubber (SBR), butadiene rubber (BR), acrylonitrile butadiene rubber (NBR), and silicone rubber. These rubbers are blended with additives such as a filler, a plasticizer, an anti-aging agent, a vulcanizing agent, a vulcanization accelerator, and a vulcanizing auxiliary as necessary.

  The elastic body 22 has a side wall elastic body 22b. The side wall elastic body 22b covers the side surfaces of the internal elastic body 22a, the reinforcing plates 23, the bridge girder connection plate 24 and the pier connection plate 25, and protects the internal elastic body 22a and the like from external impacts and the like. The material of the side wall elastic body 22b is preferably an elastic material formed in the same manner as the internal elastic body 22a and is excellent in weather resistance and external impact. For example, butyl rubber, acrylic rubber, ethylene propylene rubber (EPDM) and the like.

  Further, the thickness dimension of the side wall elastic body 22b is not uniform, and as shown in FIG. 2, the thickness dimension W1 on the bridge girder connection plate 24 and pier connection plate 25 side is the thickness dimension W2 on the reinforcing plate 23 side. Further, it is designed to be twice as large, and a protruding portion 26 protruding outward is formed on the side of each connecting plate 24, 25.

  In the elastic bearing 20 for a bridge according to the present embodiment, the protruding portion 26 is provided based on the following analysis or the like.

  That is, as shown in FIG. 3, when the bridge elastic support 20 is displaced in the direction of the bridge axis, as shown in FIGS. 4 (a) and 4 (b), each internal elastic body 22a and each reinforcing plate 23 are in the direction of the bridge axis. The elastic support portion 21 as a whole extends obliquely. As a result, distortion occurs between the internal elastic bodies 22a adjacent to the reinforcing plates 23, and this distortion is a factor for forming the recesses B1 and B2 on the outer surface of the side wall elastic body 22b.

  Here, as shown in FIG. 4A, when the thickness dimension of the side wall elastic body 22b is small, it can be understood that the dent of the recess B1 is large and the amount of shear deformation is large. On the other hand, as shown in FIG. 4B, when the thickness dimension of the side wall elastic body 22b is large, it can be understood that the recess of the recess B2 is small and the amount of shear deformation is small.

  Further, as shown in FIG. 5, the applicant conducted a surface strain analysis using an FEM model. Similar to the present embodiment, the model 100 has the reinforcing plates 103 and the internal elastic bodies 104 alternately stacked between the bridge girder connecting plates 101 and the pier connecting plates 102, and the reinforcing plates 103 and the internal elastic bodies 104. A side wall elastic body 105 is arranged on the side surface of each of these members, and these members 101 to 105 are vulcanized and bonded.

  Here, as shown in FIG. 5A, the model 100 was deformed by applying a shearing force in the direction of the bridge axis. Here, the amount of shear deformation generated on the left and right side surfaces of the model 100 was verified. As shown in FIGS. 5B and 5C, the bridge girder connection plate 101 and the pier connection plate 102 out of the outer surface of the side wall elastic body 10. It was found that the amount of shear deformation was concentrated on the side.

  Based on the above analysis and the like, the following technical structure that cannot be conceived from the inventions described in Patent Documents 1 and 2 was created. That is, in the elastic body 22, the amount of distortion deformation of the side wall elastic body 22b can be efficiently reduced by projecting the bridge girder connection plate 24 and the pier connection plate 25 side outward.

  According to the bridge elastic support 20 according to the present embodiment, the elastic body 22 has the protruding portions 26 protruding outward from the connecting plates 24 and 25 side of the elastic body 22, so that the surface distortion of the elastic body can be reduced. The projecting portion 26 is simply provided, and a very simple shear force damping structure is obtained.

  FIG. 6 shows a second embodiment of an elastic bearing for a bridge according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The bridge elastic support 30 according to the present embodiment is obtained by improving the structure of the side wall elastic body 32 b of the elastic body 32.

  In the first embodiment, only the side of each connecting plate 24, 25 is considered in the thickness dimension of the side wall elastic body, but in this embodiment, the thickness dimension on the reinforcing plate 23 side in addition to the protruding portion 36. Is also taken into consideration. In other words, the thickness dimension on the reinforcing plate 23 side is improved as the distance from the connecting plates 24 and 25 decreases. Thereby, the side wall elastic body 32b can be set to an appropriate thickness dimension without excess or deficiency according to the shear stress.

  FIG. 7 shows a third embodiment of an elastic bearing for a bridge according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the first embodiment, the protruding portion is formed on the side wall elastic body. However, the bridge elastic support 40 according to the present embodiment has the protruding portion 46 formed on the internal elastic body 42a.

  That is, as shown in FIG. 7, a protruding portion 46 is formed by protruding the bridge girder connecting plate 24 and the pier connecting plate 25 side of the inner elastic body 42 a of the elastic body 42 in the outward direction. The side wall elastic body 42b is bonded substantially uniformly to the outer surface of the internal elastic body 42a.

  Also in the bridge elastic support 40 according to the present embodiment, since the thickness dimension on the side of each of the connecting plates 24 and 25 is large, a damping effect can be sufficiently exerted against the shear deformation applied to the elastic body 42. .

  FIG. 8 shows a fourth embodiment of an elastic bearing for a bridge according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the first embodiment, the bridge girder connection plate 24 and the bridge pier connection plate 25 are arranged above and below as the plates for holding the elastic body 22 and the reinforcing plate 23. However, as shown in FIG. 8, the bridge according to this embodiment is provided. In the elastic bearing 50 for use, each of the connecting plates 24 and 25 is also used as the upper rod 12 and the lower rod 14. According to the present embodiment, the structure is simplified because the connecting plates 24 and 25 are removed.

  FIG. 9 shows a fifth embodiment of an elastic bearing for a bridge according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The elastic body 22 according to the first embodiment is configured by the internal elastic body 22a and the side wall elastic body 22b, but the bridge elastic support 60 according to the present embodiment includes the elastic body 62 only by the internal elastic body 62a. ing. That is, even in the bridge elastic bearing 60 of the type having no side wall elastic body, by forming the protruding portion 66 on the internal elastic body 62a, the same operation effect as the first embodiment is exhibited.

  In each of the above embodiments, the protrusions 26, 36, 46, 66 are formed not only on the surface of the elastic body facing the bridge axis direction, but also on the side surface along the bridge axis direction adjacent thereto. Since the portion that greatly deforms due to temperature or the like is the side surface facing the bridge axis direction, it is necessary to provide at least the facing side surface.

  20, 30, 40, 50, 60 ... elastic support for bridge, 21 ... elastic support, 22 ... elastic body, 22a ... internal elastic body, 22b ... side wall elastic body, 23 ... reinforcing plate, 24 ... bridge girder connection plate, 25 ... Abutment connection plate, 26, 36, 46, 66 ... Projection.

Claims (5)

A plurality of reinforcing plates arranged at intervals, an elastic support portion constituted by an elastic body covering each of the reinforcing plates, a bridge girder connecting plate for connecting the elastic body to the bridge girder side, and connecting the elastic body to the pier In an elastic bearing for a bridge comprising a pier connection plate and reducing deformation force applied to the pier from the bridge girder,
The elastic support for bridges, wherein the elastic body has a protruding portion that protrudes outward from the bridge girder connecting plate side and the pier connecting plate side. The elastic body includes an internal elastic body that is alternately laminated and bonded to the reinforcing plates, and a side wall elastic body that covers side surfaces of the internal elastic bodies, the reinforcing plates, the bridge girder connecting plate, and the pier connecting plate. The elastic bearing for bridge according to claim 1, wherein the protruding portion is formed on the side wall elastic body. The elastic body includes an internal elastic body that is alternately laminated and bonded to the reinforcing plates, and a side wall elastic body that covers side surfaces of the internal elastic bodies, the reinforcing plates, the bridge girder connecting plate, and the pier connecting plate. The elastic bearing for a bridge according to claim 1, wherein the protruding portion is formed on the internal elastic body and the side wall elastic body is formed so as to substantially uniformly cover a side surface of the internal elastic body. The elastic support for a bridge according to any one of claims 1 to 3, wherein the protruding portion has at least a side surface orthogonal to a bridge axis direction among the side surfaces of the elastic support body. The elastic bearing for a bridge according to any one of claims 1 to 4, wherein the elastic body on the side of each reinforcing plate is formed to be thinner as the distance from the bridge girder connection plate and the bridge pier connection plate is increased.

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