JP2016132927A - Fixing structure between anchor bolt and metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing structure that uniformly conveys force between a plurality of anchor bolts and a metal plate, at the same time preventing deformation of the metal plate.SOLUTION: A fixing structure between a plurality of anchor bolts 2 embedded in a concrete structure 52 and a metal plate 1 installed on a surface of the concrete structure 52 includes: a cylindrical coupler 3 to be embedded in the concrete structure 52, having a tip part of an anchor bolt 2 screwed into a half part on one side of a female screw part 6 formed on an inner periphery of the fixing structure; a tapered ring 4 fitted in a tapered hole 8 formed through the metal plate 1 such that a diameter tapers toward the concrete structure 52 side, the tapered ring having an outer peripheral tapered surface 4a fitted to the tapered hole, and a stepped part 9 with a widened diameter along an inner periphery at an edge part on a front surface side of the metal plate 1; and a bolt 5 having a flange 11 to be engaged with the stepped part 9 at a rear edge part, the bolt being fitted into an inner periphery of the tapered ring 4 and having a tip part screwed into the other half part of the female screw part 6.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a structure for fixing an anchor bolt and a metal plate. More specifically, for example, an anchor bolt embedded in a lower structure in a bridge and a base plate for attaching a support installed between upper and lower structures. It relates to a fixed structure.

  The support installed between the upper and lower structures in the bridge is mounted and fixed on the base plate installed in the lower structure. The base plate is fixed to anchor bolts embedded in the lower structure.

  Conventionally, the base plate is made larger than the lower arm so as to protrude from the lower arm of the support to the four sides. And the upper end part of an anchor bolt penetrates and protrudes from the overhang | projection part of this base plate, and the base plate is being fixed to the anchor bolt by attaching a nut to a protrusion part. Therefore, the base plate can be easily replaced by removing the nut.

  However, the base plate fixing structure as described above requires a large installation space for the support, and the base plate is also large, resulting in high costs. In order to avoid this, a fixing structure is also known in which the size of the base plate is approximately the same as the size of the lower eyelid and is compact with no overhanging portion. In this case, the upper end portion of the anchor bolt is attached to a screw hole provided in the base plate so as not to protrude from the surface of the base plate. However, with such a fixing structure, when replacing the base plate, the concrete around the anchor bolts must be scraped, and replacement is not easy.

  For this reason, a technique has been proposed in which the base plate can be easily replaced in the base plate fixing structure that has been made compact (see Patent Document 1). In this fixing structure, a nut with a flange is fitted into a through hole provided in a base plate, and an upper end portion of an anchor bolt is screwed to the nut. According to this fixing structure, since the nut is detached from the anchor bolt by rotating the nut using a jig, the base plate can be easily replaced.

  However, the following problems can be pointed out regarding this conventional one. That is, since the outer periphery of the nut screwed to the anchor bolt is a straight cylinder, backlash tends to occur between the inner periphery of the through hole due to manufacturing errors and the like. As a result, the transmission of force between the plurality of anchor bolts and the base plate becomes uneven, and the base plate may be deformed when an uplift force acts on the support. Further, if the through hole of the new base plate and the core of the existing anchor bolt are misaligned at the time of replacement, the nut cannot be screwed to the anchor bolt, and it becomes difficult to attach the base plate.

JP 2010-275777A

The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a fixing structure that can make force transmission uniform between a plurality of anchor bolts and a metal plate, and can prevent deformation of the metal plate.
Another object of the present invention is to provide a fixing structure capable of fixing a metal plate to an anchor bolt even if there is a misalignment between the hole of a new metal plate used for replacement and the core of an existing anchor bolt. There is to do.

The present invention employs the following means in order to achieve the above object.
That is, this invention is a fixing structure of a plurality of anchor bolts embedded in a concrete structure and a metal plate installed on the surface of the concrete structure,
A cylindrical coupler in which the tip of the anchor bolt is screwed into one half of the female thread portion formed on the inner periphery, and embedded in the concrete structure;
The metal plate has an outer peripheral tapered surface that is fitted into a tapered hole that penetrates the metal plate so that the diameter gradually decreases toward the concrete structure side, and that fits the inner periphery of the tapered hole. A taper ring having a stepped portion with an enlarged diameter on the inner periphery of the surface side end of
A flanged bolt having a flange engaged with the stepped portion at the rear end portion, the front end portion being screwed into the other half portion of the female threaded portion and being fitted inward of the tapered ring. It is in the fixing structure of the anchor bolt and metal plate characterized by these.

  In the fixing structure, a configuration in which an eccentric ring in which an inner diameter center and an outer diameter center are eccentric is fitted between the inner periphery of the taper ring and the outer periphery of the bolt can be employed.

  In the fixed structure, for example, the concrete structure is a lower structure in a bridge, and the metal plate is a base plate for installing a support between the upper and lower structures.

According to this invention, transmission of force between a plurality of anchor bolts and the metal plate can be made uniform, and deformation of the metal plate can be prevented.
Moreover, according to this invention, even if there is a shift in the core between the hole of a new metal plate used for replacement and the existing anchor bolt, the metal plate can be fixed to the anchor bolt.

It is the fragmentary sectional view which showed the installation state of the support in the bridge where the fixed structure by this invention is applied, and was seen to the bridge axis direction. It is sectional drawing which shows embodiment of the fixing structure by this invention. It is a top view which shows the same embodiment. The jig | tool used for attachment / detachment of a bolt with a flange is shown, (a) is a top view, (b) is a front view.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view showing the installation state of a support in a bridge to which a fixing structure according to the present invention is applied, as viewed in the direction of the bridge axis. A rubber bearing 50 is shown as the bearing. The rubber bearing 50 is installed between a girder (the steel girder in the illustrated example) that is the upper structure 51 and a concrete pier (or abutment) that is the lower structure 52.

  The rubber bearing 50 is well known and includes an upper collar 53, a lower collar 54, and a rubber collar 55 disposed between the upper and lower collars 53, 54. The rubber cage 55 is composed of thick upper and lower steel plates 56 and 57, rubber layers 58 and thin inner steel plates 59 that are alternately stacked between them. The upper steel plate 56 is fixed to the upper rod 53, and the lower steel plate 57 is fixed to the lower rod 54 by a plurality of bolts 60, respectively.

  A sole plate 61 is fixed to the lower surface of the upper structure 51 by welding or the like. The sole plate 61 is provided with a fitting hole 63 of a shear key 62 in the center thereof, and the upper end portion of the shear key 62 attached to the upper collar 53 is fitted into the fitting hole 63. With the shear key 62 fitted, the upper collar 53 is fixed to the upper structure 51 (steel girder flange) by a plurality of set bolts 64.

  The lower rod 54 is provided with a fitting hole 66 for a shear key 65 at the center, and the shear key 65 attached to the lower steel plate 57 of the rubber rod 55 is fitted in the fitting hole 66. The lower collar 54 is fixed to the base plate 1 having the same size as the lower collar 54 installed on the upper surface of the lower structure 52 by a plurality of bolts 67. The base plate 1 is fixed to a plurality of anchor bolts 2 embedded in the lower structure 52. The upper collar 53, the lower collar 54, the sole plate 61, the base plate 1 and the like described above are all made of steel and rectangular.

  2 and 3 show a fixing structure between the anchor bolt 2 and the base plate 1, FIG. 2 is a sectional view, and FIG. 3 is a plan view. The fixing structure includes a tubular coupler 3, a tapered ring 4, a flanged bolt 5, and an eccentric ring 12.

  The coupler 3 is embedded in the lower structure 52 so that the upper end surface thereof is substantially flush with the upper surface of the lower structure 52. An internal thread portion 6 is formed on the inner periphery of the coupler 3. A male screw portion 7 formed at the upper end portion of the anchor bolt 2 is screwed into the lower half portion of the coupler 3. The anchor bolt 2 is embedded in the lower structure 52 in a state where the coupler 3 is mounted when the concrete of the lower structure 52 is applied.

  The base plate 1 is provided with a tapered hole 8 having a diameter gradually decreasing toward the lower structure 52 side, penetrating the base plate 1. The tapered ring 4 is fitted into the tapered hole 8, and the tapered ring 4 has an outer peripheral tapered surface 4 a that fits the inner periphery of the tapered hole 8. When the taper ring 4 is fitted in the taper hole 8, the upper end surface thereof is substantially flush with the surface of the base plate 1. The tapered ring 4 is formed with a stepped portion 9 whose diameter is increased on the inner periphery of the upper end (the inner periphery of the surface side end of the base plate 1).

  The bolt 5 with a flange has a male screw portion 10 at the front end portion and a flange 11 at the rear end portion. The flanged bolt 5 is fitted inside the taper ring 4, and its tip 10 is screwed into the upper half of the coupler 3. With the flanged bolt 5 screwed into the coupler 3, the flange 11 is engaged with the stepped portion 9 of the taper ring 4, and the upper end surface of the flange 11 and the upper end surface of the taper ring 4 are flush with each other.

  The eccentric ring 12 is fitted between the outer periphery of the shaft portion of the flanged bolt 5 and the inner periphery of the tapered ring 4. As shown in FIG. 3, the eccentric ring 12 has its inner diameter center and outer diameter center eccentric by δ.

  FIG. 4 shows a jig used when the flanged bolt 5 is screwed into or removed from the coupler 3, (a) is a plan view, and (b) is a front view. The jig 20 is formed by fixing a flange 22 to the lower end of the hexagon nut 21 by welding or the like. A plurality of protrusions 23 (four in the illustrated example) are provided on the lower surface of the flange 22. On the other hand, the upper surface of the flange 11 of the flanged bolt 5 is provided with a plurality of recesses 24 corresponding to the protrusions 23 (see FIGS. 2 and 3). When attaching / removing the flanged bolt 5, the projection 23 of the jig 20 is fitted into the recess 24 of the flange 11, and a wrench is applied to the nut 21 to rotate the bolt 5.

  According to the fixing structure as described above, when the flanged bolt 5 is screwed into the coupler 3, the flange 11 presses the taper ring 4 downward. As a result, the tapered ring 4 is brought into close contact with the base plate 1 by pressing the outer peripheral tapered surface 4 a against the inner periphery of the tapered hole 8 by the wedge action. Thereby, transmission of force between the plurality of anchor bolts 2 and the base plate 1 can be made uniform, and deformation of the base plate 1 can be prevented.

  When the base plate 1 is replaced, the bolt 64 and the bolt 67 shown in FIG. 1 are removed, the upper structure 51 is jacked up, and the rubber bearing 50 is pulled out from between the sole plate 61 and the base plate 1 in the horizontal direction. As a result, the base plate 1 is exposed. Then, the flanged bolt 5 is removed to remove the existing base plate 1, and the new base plate 1 is fixed to the existing anchor bolt 2 via the coupler 3 using the taper ring 4 and the flanged bolt 5.

  At this time, there is a possibility that the inner diameter center of the taper ring 4 and the inner diameter center of the coupler 3 (core of the anchor bolt 2) are decentered due to a processing error of the plurality of tapered holes 8 provided in the base plate 1. However, in the present invention, since the eccentric ring 12 is fitted between the outer periphery of the flanged bolt 5 and the inner periphery of the taper ring 4, the center of the inner diameter of the eccentric ring 12 is coupled to the coupler by appropriately rotating the eccentric ring 12. 3 can coincide with the center of the inner diameter. That is, the flanged bolt 5 can be screwed into the coupler 3 through the eccentric ring 12.

  The above embodiment is merely an example, and the present invention can take various aspects. For example, in the above embodiment, the present invention is applied to a fixing structure of a base plate and an anchor bolt for installing a support in a bridge. However, the present invention is not limited to this, and the present invention is an anchor bolt embedded in a concrete structure. It is generally applicable to a fixed structure between a metal plate installed on the surface of a concrete structure.

1: Base plate 2: Anchor bolt 3: Coupler 4: Tapered ring 5: Bolt with flange 6: Female thread portion 8: Tapered hole 9: Stepped portion 11: Flange 12: Eccentric ring

Claims (3)

A fixed structure of a plurality of anchor bolts embedded in a concrete structure and a metal plate installed on the surface of the concrete structure,
A cylindrical coupler in which the tip of the anchor bolt is screwed into one half of the female thread portion formed on the inner periphery, and embedded in the concrete structure;
The metal plate has an outer peripheral tapered surface that is fitted into a tapered hole that penetrates the metal plate so that the diameter gradually decreases toward the concrete structure side, and that fits the inner periphery of the tapered hole. A taper ring having a stepped portion with an enlarged diameter on the inner periphery of the surface side end of
A flanged bolt having a flange engaged with the stepped portion at the rear end portion, the front end portion being screwed into the other half portion of the female threaded portion and being fitted inward of the tapered ring. An anchor bolt and metal plate fixing structure.   2. An anchor bolt and a metal according to claim 1, wherein an eccentric ring having an inner diameter center and an outer diameter center eccentric is fitted between an inner circumference of the taper ring and an outer circumference of the flanged bolt. Fixed structure with plate.   3. The anchor bolt and the metal plate are fixed to each other according to claim 1, wherein the concrete structure is a lower structure in a bridge, and the metal plate is a base plate for installing a support between upper and lower structures. Construction.

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