JP5324949B2 - Bridge fall prevention device - Google Patents

Description

  The present invention relates to a bridge fall prevention tool that connects two bridge structures such as bridge girders or bridge girders and piers to prevent the bridge from falling.

  In order to prevent the bridge from falling by connecting the bridge girders constituting the bridge or by connecting the bridge girders and the bridge piers, there has been proposed a falling bridge prevention device as described in Patent Document 1. The falling bridge prevention device connects the bridge girders and the like using the connecting cable 4, and cushions the impact when the bridge girders collide with each other by the buffer rubber 16.

  However, the falling bridge prevention device described in Patent Document 1 has a complicated mechanism in which a buffer function and a clearance are provided at both ends of the connection cable 4. Moreover, since the size of the bracket 5 for attachment to a bridge pier etc. becomes large, an attachment position will be restricted. Furthermore, a buffering function is provided using only the compression deformation of rubber.

Japanese Patent No. 3124500

  In consideration of such facts, an object of the present invention is to provide a bridge fall prevention device having a buffering function with a simple configuration.

In order to solve the above-mentioned problem, the bridge fall prevention device according to claim 1 is an elastic body having a curved shape and having one end portion and the other end portion, and a first end side is fixed to the first bridge structure. An end side is fixed to a second bridge structure different from the first bridge structure, the first end side is arranged on the one end portion side of the elastic body, and the second end side is the other end portion of the elastic body. with a PC steel intermediate portion is disposed on the side is embedded in the elastic body, the intermediate portion of the PC steel material, that is embedded is curved by the elastic body, it characterized.

  In the bridge fall prevention device having the above-described configuration, the first end side of the PC steel material is fixed to the first bridge structure, and the second end side is fixed to the second bridge structure different from the first bridge structure. The fixing of the PC steel material to the first bridge structure and the second bridge structure can be performed by any appropriate method according to the fixing position, space, and the like.

  The relative length of the first bridge structure and the second bridge structure due to the constant girder moving body, such as temperature changes, has room for at least one of the lengths of the PC steel material at the first and second ends. By giving, it is possible to follow the relative movement.

  When the first bridge structure and the second bridge structure are separated from each other due to an earthquake or the like and a tensile force acts on the PC steel material, the tensile force acts on the elastic body and the curved portion is deformed so as to be linear. At this time, the impact during pulling can be reduced by the bending deformation resistance of the elastic body.

  The bridge fall prevention tool according to claim 2 is characterized in that the elastic body is U-shaped from the one end to the other end.

  In this way, by making the elastic body U-shaped, it is possible to efficiently relieve the impact when a tensile force acts on both ends of the U-shape. Moreover, it can comprise compactly by using U character.

The bridge fall prevention device according to claim 1 is characterized in that an intermediate portion of the PC steel material is curved and embedded in the elastic body.

  As described above, the PC steel material is also deformed so that the elastic body becomes linear by curving a portion in the elastic body, and then the PC steel material is linearly deformed in the elastic body. At this time, since the elastic body adhered to the PC steel material tries to follow the deformation of the PC steel material, deformation resistance such as compression and tension occurs. Thereby, the impact at the time of a tension | pulling can be relieve | moderated further.

The bridge fall prevention tool according to claim 3 is characterized in that the PC steel material has a coil spring shape at least in an intermediate portion.
The bridge fall prevention tool according to claim 4 is characterized in that the elastic body is curved in a wave shape in a side view.

  Thus, by making the shape of the PC steel material embedded in the elastic body into a coil spring shape, the elasticity that was adhered to the PC steel material during the linear deformation of the PC steel material after the elastic body was deformed so as to be linear. Since the body tries to follow the deformation of the PC steel material, deformation resistance such as bending and twisting occurs in addition to compression and tension. Further, by adopting a coil spring shape, the volume of the PC steel material per unit volume of the elastic body can be increased rather than simply curving, and the above-described deformation resistance can be increased. Thereby, the impact at the time of a tension | pulling can be relieve | moderated further.

  The bridge fall prevention tool of the present invention can have a buffer function with a simple configuration.

It is a figure which shows schematic structure of the bridge fall prevention tool which concerns on 1st Embodiment. (A)-(C) are explanatory drawings which show the manufacturing process of the bridge fall prevention tool which concerns on 1st Embodiment. It is a figure showing the state where the bridge fall prevention tool concerning a 1st embodiment was attached. It is an enlarged view of an attachment part when the bridge fall prevention tool concerning a 1st embodiment is attached. It is a figure which shows schematic structure of the modification (A)-(C) of the bridge fall prevention tool which concerns on 1st Embodiment. It is a figure which shows schematic structure of the bridge fall prevention tool which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the modification (A)-(B) of the bridge fall prevention tool which concerns on 2nd Embodiment.

  [First embodiment]

  As shown in FIG. 1, the bridge drop prevention tool 10 of this embodiment includes an elastic body 12 that is curved in a substantially U shape in a side view. The elastic body 12 has a circular cross section, and one end side and the other end side of the U-shape are an end portion 14 and the other end portion 16, respectively. In addition, the cross section of the elastic body 12 does not necessarily need to be circular, and may be a polygon such as a quadrilateral octagon or an elliptical shape. The elastic body 12 can be made of a rubber material such as natural rubber, synthetic rubber or fiber rubber, or a resin material having elasticity.

  An intermediate portion 22 of the PC steel material 20 is embedded in the elastic body 12. The PC steel material 20 can be constituted by a PC steel stranded wire (PC cable), a PC steel bar, or the like. The intermediate portion 22 of the PC steel material 20 has a coil spring shape. The PC steel material 20 has a first end 24 exposed to the outside from one end 14 of the elastic body 12 and a second end 26 exposed to the outside from the other end 16 of the elastic body 12. The PC steel material 20 is composed of a PC steel material 20 in which a first end portion 24, an intermediate portion 22, and a second end portion 26 are continuous. Since the intermediate portion 22 of the PC steel material 20 is embedded in the elastic body 12, the weather resistance can be improved as compared with the case where the PC steel material 20 is exposed. Further, since the intermediate portion 22 of the PC steel material 20 has a coil pulling shape, it is possible to increase the volume of the PC steel material 20 per unit volume of the elastic body 12 rather than simply curving it. In this case, the resistance can be increased.

  The bridge fall prevention tool 10 can be manufactured as follows, for example.

  As shown in FIG. 2A, a two-part mold 36 having a shape corresponding to the shape of the elastic body 12 and the first end 24 and the second end 26 is prepared. ), The PC steel material 20 formed in a coil spring shape in advance is set in the mold 36. Then, as shown in FIG. 2C, rubber is injected from the injection port 36E and vulcanized. In addition, it is not based on injection | pouring, but PC steel material 20 can be arrange | positioned in unvulcanized rubber, and it can also shape | mold by rolling molding.

  In addition, when using a thermoplastic resin as a material of the elastic body 12, it can manufacture by inject | pouring a high temperature thermoplastic resin from the injection port 36E, and cooling. Also,

  When the bridge fall prevention device 10 having the above-described configuration is attached, the first end 24 is fixed to the pier 30 as the first bridge structure, and the second end 26 is fixed to the bridge girder 32 as the second bridge structure. To do. The bridge girder 32 is supported by the pier 30 via the support 31. The fixing method can be selected according to the mounting position, the size of the mounting area, and the like.

  The above attachment can be performed, for example, as shown in FIG. As shown in FIG. 4, first, the tips of the first end portion 24 and the second end portion 26 are fixed to the tip fixture 40 on which the male screw 40N is formed. On the other hand, a support plate 46 to which a mounting plate 42 and two rib plates 44 are welded is fixed to the bridge pier 30 and the bridge girder 32 with an anchor bolt or the like. At the center of the mounting plate 42, a hole 42A through which the PC steel material 20 can be inserted is drilled. The two rib plates 44 are fixed on the back side of the mounting plate 42 so as to be orthogonal to the mounting plate 42.

  Next, the tip fixing tool 40 is inserted into the hole 42A, and the two nuts 47 are screwed into the male screw of the tip fixing tool 40 through a washer 45 having an outer diameter larger than that of the hole 42A. By the nut 47, the PC steel material 20 is prevented from being detached from the mounting plate 42 and fixed. The outside of the attachment portion is covered with a cover 48. The first end portion 24 and the second end portion 26 of the PC steel material 20 have a length that can follow the relative movement between the bridge pier 30 and the bridge girder 32 in advance by loosening or the like.

  As described above, the bridge drop prevention tool 10 of the present embodiment has a simple configuration, and can be appropriately attached according to the attachment position and space.

  Next, the operation of the bridge fall prevention tool 10 in which the first end 24 is fixed to the bridge pier 30 and the second end 26 is fixed to the bridge girder 32 as described above will be described.

  When the pier 30 and the bridge girder 32 expand and contract due to heat or the like and move relative to each other, the first end portion 24 and the second end portion 26 of the PC steel material 20 follow each other by stretching or loosening. According to the present embodiment, the PC steel material 20 is allowed to follow the relative movement of the bridge pier 30 and the bridge girder 32 at normal times with a simple configuration without requiring a complicated configuration such as providing a clearance in the case. Can do.

  When a large vibration is input to the bridge pier 30 and the bridge girder 32 due to an earthquake or the like and the bridge girder 32 is relatively moved in the direction of dropping from the pier 30, first, the first end portion 24 and the second end portion 26 of the PC steel material 20 Is stretched. Next, the U-shape of the elastic body 12 is expanded and deformed into a rod shape. At this time, a bending deformation resistance (first deformation resistance) of the elastic body 12 is generated. After the elastic body 12 is deformed into a rod shape, the intermediate portion 22 of the PC steel material 20 is stretched and deformed into a linear shape. At this time, the elastic body 12 bonded to the intermediate portion 22 follows the deformation and locally generates deformation resistance (second deformation resistance) such as compression, tension, bending, and twisting.

  As described above, a high buffering function can be obtained by the two-stage deformation resistances of the first deformation resistance and the second deformation resistance.

  In the present embodiment, only the intermediate portion 22 of the PC steel material 20 has a coil spring shape. However, as shown in FIG. 5A, the first end portion 24 and the second end portion 26 also have a coil spring shape. It is good. Thus, by making the first end portion 24 and the second end portion 26 into a coil spring shape, the extended portion of the PC steel material 20 at the normal time can be made compact.

  Moreover, in this embodiment, although the intermediate part 22 of PC steel material 20 was made into the coil spring shape, as shown to FIG. 5 (B), it is good also as the curved intermediate part 22A curved.

  Further, as shown in FIG. 5C, the intermediate portion 22 of the PC steel material 20 may be simply an intermediate portion 22 </ b> A having a shape along the U shape of the elastic body 12.

  [Second Embodiment]

  Next, a second embodiment will be described. In the present embodiment, the description of the same parts as those in the first embodiment is omitted.

  As shown in FIG. 6, the bridge drop prevention tool 50 of this embodiment includes an elastic body 52 that is curved in a wave shape having a predetermined amplitude in a side view. The elastic body 52 has a circular cross section, and one end side and the other end side of the wavy form are one end portion 54 and the other end portion 56, respectively. The cross section of the elastic body 52 is not necessarily circular, but may be a polygon such as a quadrilateral octagon or an elliptical shape. The elastic body 52 can be made of a rubber material such as natural rubber, synthetic rubber or rubber containing fiber, or a resin material having elasticity.

  An intermediate portion 62 of the PC steel material 60 is embedded in the elastic body 52. The PC steel material 60 can be composed of a PC steel strand (PC cable) or the like. The intermediate portion 62 of the PC steel material 60 has a coil spring shape. The PC steel material 60 has a first end portion 64 exposed to the outside from one end portion 54 of the elastic body 52, and a second end portion 66 exposed to the outside from the other end portion 56 of the elastic body 52. The PC steel material 60 is composed of a PC steel material 60 in which a first end portion 64, an intermediate portion 62, and a second end portion 66 are continuous.

  Manufacture and attachment of the bridge drop prevention tool 50 can be performed in the same manner as in the first embodiment. Further, the action of the bridge fall prevention tool 50 is the same as that of the first embodiment.

  In the present embodiment, only the intermediate portion 62 of the PC steel material 60 has a coil spring shape. However, as shown in FIG. 7A, the first end portion 64 and the second end portion 66 also have a coil spring shape. It is good. As described above, by forming the first end portion 64 and the second end portion 66 in a coil spring shape, the extended portion of the PC steel material 60 at the normal time can be made compact.

  In the present embodiment, the intermediate portion 62 of the PC steel material 60 has a coil spring shape. However, as shown in FIG. 7B, the intermediate portion 62A having a shape along the wave shape of the elastic body 52 may be used.

DESCRIPTION OF SYMBOLS 10 Bridge fall prevention tool 12 Elastic body 14 One end part 16 Other end part 20 PC steel material 22 Intermediate part 24 1st end part 26 2nd end part 50 Bridge fall prevention tool 52 Elastic body 54 One end part 56 Other end part 60 PC steel material 62 Intermediate part 64 First end part 66 Second end part

Claims (4)

An elastic body that is curved and has one end and the other end;
The first end side is fixed to the first bridge structure, the second end side is fixed to a second bridge structure different from the first bridge structure, and the first end side is arranged on the one end side of the elastic body. A PC steel material in which the second end side is disposed on the other end side of the elastic body and an intermediate portion is embedded in the elastic body;
With
The bridge fall prevention tool , wherein the intermediate portion of the PC steel material is curved and embedded in the elastic body .   The bridge fall prevention tool according to claim 1, wherein the elastic body has a U shape extending from the one end to the other end.   The bridge fall prevention tool according to claim 1 or 2, wherein the PC steel material has a coil spring shape at least in an intermediate portion. The bridge drop prevention tool according to claim 1, wherein the elastic body is curved in a wave shape in a side view.

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