JP4493222B2 - Laminated rubber bearing and structure for fixing the bearing to a structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated rubber bearing and a structure for fixing the bearing to a structure, and more particularly to a laminated rubber bearing installed between an upper structure and a lower structure in a bridge.
[0002]
[Prior art]
A laminated rubber bearing widely known as a horizontal force dispersion bearing in a bridge generally has a structure as shown in FIG. That is, the laminated rubber bearing 50 is fixed to the rubber bearing main body 51 in which the rubber layers 56 and the intermediate steel plates 57 are alternately laminated between the upper steel plate 54 and the lower steel plate 55, and to the upper and lower portions thereof by the bolts 60. It consists of an upper rod 58 and a lower rod 59.
[0003]
In the laminated rubber bearing 50, an upper collar 58 is fixed by a bolt 63 to a sole plate 62 fixed to the lower surface of the upper structure 52 via an anchor bar 61. Further, a lower collar 59 is fixed to the base plate 65 fixed to the upper surface of the lower structure 53 via the anchor bolt 64 by the bolt 66, and the laminated rubber bearing 50 is thus installed between the upper and lower structures 52, 53. . The shear keys 67 and 68 are for transmitting a horizontal force between the rubber bearing body 51 and the upper and lower collars 58 and 59.
[0004]
This structure for fixing the bearing is because the replacement of the rubber bearing is taken into consideration. However, since an upper collar and a lower collar are required, the weight is increased and the number of holes is increased, resulting in an increase in cost. Therefore, a rubber bearing that eliminates the upper and lower collars has been proposed as a replacement of the bearings.
[0005]
However, in this case, the following problem occurs. That is, if the anchor bolt is screwed directly into the lower steel plate, the lower steel plate needs to have a plate thickness equivalent to the required screw length (anchor bolt screw diameter x 0.8 mm or more), and the anchor bolt is usually large in diameter. The plate thickness is also increased and the manufacturing cost is increased.
[0006]
[Problems to be solved by the invention]
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 laminated rubber bearing and a structure for fixing the bearing to a structure that can reduce the weight and reduce the number of processing steps to reduce the cost.
Another object of the present invention is to provide a laminated rubber bearing that can be easily replaced in addition to the above object, and a structure for fixing the bearing to a structure.
[0007]
[Means for Solving the Problems]
The present invention employs the following means in order to achieve the above object.
That is, this invention is a laminated rubber bearing having upper and lower steel plates at the upper and lower ends, and a plurality of rubber layers and intermediate steel plates are alternately laminated between the upper and lower steel plates,
In a plurality of mounting holes provided in the lower steel plate, a cylindrical coupler having a screw formed on the inner periphery is inserted and fixed,
These couplers have protrusions that protrude downward from the mounting holes ,
In the laminated rubber bearing, the outer periphery of the coupler and the inner periphery of the mounting hole are provided with stepped portions that engage with each other .
[0008]
The coupler is screwed with a retaining ring having a thread formed on the outer periphery. The retaining ring has a stepped portion on the inner periphery, and is supported by the stepped portion inside the retaining ring and accommodates an inner nut. It is good also as the aspect currently performed.
[0009]
Further, the present invention is fixedly installed between the upper structure and the lower structure, and has upper and lower steel plates at upper and lower ends, and a plurality of rubber layers and intermediate steel plates are alternately laminated between the upper and lower steel plates, respectively. A laminated rubber bearing fixing structure,
In a plurality of mounting holes provided in the lower steel plate, a cylindrical coupler having a screw formed on the inner periphery is inserted and fixed,
These couplers have protrusions that protrude downward from the mounting holes ,
Stepped portions that engage with each other are provided on the outer periphery of the coupler and the inner periphery of the mounting hole,
The lower steel sheet is fixed to the lower structure by anchor bolts screwed to the coupler and embedded in the lower structure.
[0010]
More specifically, the upper steel plate is detachably fixed to a sole plate fixed to the upper structure. The coupler is screwed with a retaining ring having a thread formed on the outer periphery. The retaining ring has a stepped portion on the inner periphery, and is supported by the stepped portion inside the retaining ring and accommodates an inner nut. It is good also as the aspect currently performed.
[0011]
In the present invention, the anchor bolt is not directly fixed to the lower steel plate, but is fixed via a coupler attached to the lower steel plate. For this reason, since the required thread length of the anchor bolt can be adjusted by the length of the coupler, the lower steel plate can be made thin, and the weight of the entire laminated rubber bearing can be reduced. And since the coupler used for such a purpose has the protrusion part which protrudes from the attachment hole, this protrusion part can be utilized as a shear key for the shear test at the time of factory shipment.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view along the bridge axis direction showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. The laminated rubber bearing 1 is installed between an upper structure 2 and a lower structure 3 in a bridge. In this embodiment, a concrete girder (RC girder or PC girder) is shown as the upper structure 2, and a concrete pier is used as the lower structure 3. It is shown.
[0013]
The laminated rubber bearing 1 has a thick upper steel plate 4 and a lower steel plate 5, and a plurality of rubber layers 6 and thin intermediate steel plates 7 are alternately laminated between the upper and lower steel plates 4, 5. Is formed. The upper and lower steel plates 4 and 5, the rubber layer 6 and the intermediate steel plate 7 are integrally formed by vulcanization adhesion. As the rubber material of the rubber layer 6, natural rubber, chloroprene rubber, high damping rubber obtained by adding damping to natural rubber, and the like can be used as in the conventional laminated rubber bearing.
[0014]
The upper steel plate 4 is of a flange type projecting from the laminated rubber portion where the rubber layer 6 and the intermediate steel plate 7 are laminated to the outer periphery, and a concave portion 9 for fitting the shear key 8 is formed on the upper surface. Is formed. The lower steel plate 5 has the same outer dimensions as the intermediate steel plate 7 and is provided with a plurality of coupler mounting holes 10 into which cylindrical couplers 11 are inserted and fixed.
[0015]
FIG. 3 is an enlarged cross-sectional view showing the attachment state of the coupler 11. The coupler 11 shown in FIG. 3 is a bag-like one having a screw 12 formed on the inner periphery, and an annular stepped portion 13 is formed on the upper outer periphery. On the other hand, an annular stepped portion 14 is also formed on the inner periphery of the mounting hole 10, and the stepped portions 13, 14 of the coupler 11 are engaged with each other with the coupler 11 inserted into the mounting hole 10. Yes. The coupler 11 has a protruding portion 15 that protrudes downward from the mounting hole 10 in a state of being inserted into the mounting hole 10. Thereby, as the length of the screw 12 of the coupler 11, it is possible to ensure a necessary screw length corresponding to the length of the screw 17 of the anchor bolt 16 screwed thereto.
[0016]
The outer periphery of the coupler 11 is fixed to the lower steel plate 5 by welding 18. In this case, as will be described later, the uplift force acting on the laminated rubber bearing is transmitted through the stepped portions 13 and 14, so that the welding allowance is considered only considering the detent between the coupler 11 and the anchor bolt 16. Therefore, it is possible to minimize the occurrence of distortion due to welding in the lower steel plate 5. In the illustrated example, the groove processing for the weld 18 is performed on the coupler 11, but may be performed on the lower steel plate 5 (the same applies to the examples shown in other drawings).
[0017]
The laminated rubber bearing 1 is fixed to the upper structure 2 and the lower structure 3 as follows. Referring again to FIG. 1, a sole plate 20 is fixed to the lower surface of the upper structure 2 by a plurality of anchor bars 21. A recess 22 is formed on the lower surface of the sole plate 20, and the upper steel plate 4 is fixed to the sole plate 20 with a bolt 23 in a state where the shear key 8 is fitted in the recess 22. On the other hand, the lower steel plate 5 is fixed to the lower structure 3 by embedding the anchor bolts 16 screwed to the coupler 11 when the lower structure 3 is poured into the concrete.
[0018]
In the laminated rubber bearing 1 fixed as described above, the earthquake horizontal force acting between the upper and lower structures 2 and 3 is transmitted between the upper structure 2 and the laminated rubber bearing 1 through the shear key 8. Then, the lower structure 3 and the laminated rubber support 1 are transmitted to each other via the coupler 11, and the laminated rubber support 1 undergoes shear deformation. The shear key 8 for transmitting the horizontal force is also used for setting in a testing machine in a shear test performed before shipment at a factory.
[0019]
The uplift force acting between the upper and lower structures 2 and 3 is transmitted from the anchor bolt 16 to the lower steel plate 5 through the coupler 11, more specifically through the stepped portions 13 and 14, and further to the laminated rubber portion 6. , 7, the upper steel plate 4, the sole plate 20, and the anchor bar 21 are transmitted to the upper structure 2. At this time, the bolt 23 has a function of transmitting an uplift force between the upper steel plate 4 and the sole plate 20. However, the bolt 23 can be designed to receive a horizontal force.
[0020]
According to the laminated rubber bearing 1 as described above, the anchor bolt 16 is not directly fixed to the lower steel plate 5, but is fixed via the coupler 11 attached to the lower steel plate 5, so that the necessary screw length of the anchor bolt 16 is increased. Can be adjusted by the length of the coupler 11, and the lower steel plate 5 can be made thin. Therefore, the weight of the entire laminated rubber support can be reduced. And the coupler 11 used for such a purpose will have the protrusion part 15 which protrudes from the attachment hole 10, and this protrusion part 15 can be utilized as a shear key for the shear test at the time of factory shipment.
[0021]
4 to 6 are cross-sectional views each showing another embodiment of a coupler. In the example shown in FIG. 4, the screw hole 12 of the coupler 11 is a through hole, and a cover plate 25 that closes the through hole is welded to the upper surface of the coupler 11. In the example shown in FIG. 5, the coupler 11 has a bag shape like the one shown in FIG. 3, and the annular stepped portion that engages the lower surface of the lower steel plate 5 on the outer periphery of the protruding portion 15 from the mounting hole 10 26 is provided.
[0022]
Further, in the embodiment shown in FIG. 6, in the coupler 11 having the stepped portion 26 similar to that shown in FIG. It is a thing. In the example shown in FIG. 5 and FIG. 6, the welding portion bears the lifting force, so that a welding allowance that can withstand the lifting force is required. For this reason, there is a possibility that distortion due to welding may occur in the lower steel plate 5. From the viewpoint of preventing the occurrence of this distortion, as shown above, the one shown in FIGS. 3 and 4 is a preferable embodiment.
[0023]
<Replacement of bearing>
Since the upper steel plate 4 is fixed to the upper structure 2 via the sole plate 20, the upper steel plate 4 can be easily released by removing the bolts 23. On the other hand, although the lower steel plate 5 is interposed via the coupler 11, as a result, the lower steel plate 5 is directly fixed to the lower structure 3 by the anchor bolts 16. It's not easy. That is, if the laminated rubber support 1 is to be replaced, the concrete of the lower structure 3 must be pulled until the anchor bolts 16 are exposed, and the jack-up amount at that time increases, which is a difficult task.
[0024]
FIG. 7 shows an example of a coupler structure that can be easily replaced. A retaining ring 27 having a screw 26 on the outer periphery is screwed onto the inner peripheral screw 12 of the coupler 11. Inside the holding ring 27, an inner nut 29 is accommodated while being supported by an annular stepped portion 28 formed on the inner periphery thereof. The anchor bolt 16 is screwed to the inner nut 29. A parallel portion 30 for hanging a tool such as a spanner is formed on the outer periphery of the stepped portion 28 of the holding ring 27.
[0025]
When the laminated rubber support 1 is replaced, the following is performed. The concrete on the lower surface side of the lower steel plate 5 is suspended to a depth that allows the retaining ring 27 to come out, and the retaining ring 27 is rotated with a tool and extracted. Thereby, since the edge of the anchor bolt 16 and the coupler 11 is cut, the rubber support 1 can be pulled out in the lateral direction by jacking up the upper structure 2 and raising the rubber support 1 upward. Therefore, it is not necessary to completely suspend the concrete for the length of the anchor bolt 16. Further, the jack-up amount is only required for the fitting length of the shear key 8 to the sole plate 20 and the length of the inner nut 29, so that the replacement can be easily performed.
[0026]
The laminated rubber bearing 1 according to the present invention is applicable not only when the superstructure 2 is a concrete girder but also when it is a steel girder. FIG. 8 is a cross-sectional view along the bridge axis direction showing the fixing structure. In this case, both the upper steel plate 4 and the lower steel plate 5 have the same outer dimensions as the intermediate steel plate 7, and the upper steel plate 4 is fixed by a bolt 32 penetrating the web 31 of the steel girder 2 and the sole plate 20 welded thereto. Is done. The other structure is the same as that of the concrete girder.
[0027]
【The invention's effect】
As described above, according to the present invention, since the necessary screw length of the anchor bolt can be adjusted by the length of the coupler, the lower steel plate can be made thin, and the overall weight can be reduced. . In addition, since the number of hole drilling steps as in the prior art is small, the cost can be reduced. Furthermore, replacement can be easily performed.
[Brief description of the drawings]
FIG. 1 is a sectional view along a bridge axis direction showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an enlarged cross-sectional view showing a mounting state of a coupler.
FIG. 4 is a cross-sectional view showing another embodiment of a coupler.
FIG. 5 is a cross-sectional view showing still another embodiment of a coupler.
FIG. 6 is a cross-sectional view showing still another embodiment of a coupler.
FIG. 7 is a cross-sectional view showing still another embodiment of a coupler.
FIG. 8 is a cross-sectional view showing an embodiment in which the present invention is applied when the superstructure is a steel girder.
FIG. 9 is a sectional view along a bridge axis direction showing a conventional example.
[Explanation of symbols]
1: Laminated rubber support 2: Upper structure 3: Lower structure 4: Upper steel plate 5: Lower steel plate 6: Rubber layer 7: Intermediate steel plate 8: Shear key 10: Coupler mounting hole 11: Coupler 12: Screw 13: Stepped portion 14: Stepped portion 15: Protruding portion 16: Anchor bolt 20: Sole plate 21: Anchor bar 25: Cover plate 26: Screw 27: Retaining ring 28: Stepped portion 29: Inner nut

Claims (5)

A laminated rubber bearing having upper and lower steel plates at the upper and lower ends, and a plurality of rubber layers and intermediate steel plates laminated alternately between the upper and lower steel plates,
In a plurality of mounting holes provided in the lower steel plate, a cylindrical coupler having a screw formed on the inner periphery is inserted and fixed,
These couplers have protrusions that protrude downward from the mounting holes ,
A laminated rubber bearing, wherein stepped portions that engage with each other are provided on an outer periphery of the coupler and an inner periphery of the mounting hole, respectively . The coupler is screwed with a retaining ring having a thread formed on the outer periphery. The retaining ring has a stepped portion on the inner periphery, and is supported by the stepped portion inside the retaining ring and accommodates an inner nut. The laminated rubber bearing according to claim 1, wherein the laminated rubber bearing is provided. The laminated rubber bearing is fixedly installed between the upper structure and the lower structure, and has upper and lower steel plates at the upper and lower ends, and a plurality of rubber layers and intermediate steel plates are alternately laminated between the upper and lower steel plates. A fixed structure,
In a plurality of mounting holes provided in the lower steel plate, a cylindrical coupler having a screw formed on the inner periphery is inserted and fixed,
These couplers have protrusions that protrude downward from the mounting holes ,
Stepped portions that engage with each other are provided on the outer periphery of the coupler and the inner periphery of the mounting hole,
A structure for fixing a laminated rubber bearing, wherein the lower steel plate is fixed to the lower structure by anchor bolts screwed to the coupler and embedded in the lower structure. 4. The laminated rubber bearing fixing structure according to claim 3, wherein the upper steel plate is detachably fixed to a sole plate fixed to the upper structure. The coupler is screwed with a retaining ring having a thread formed on the outer periphery. The retaining ring has a stepped portion on the inner periphery, and is supported by the stepped portion inside the retaining ring and accommodates an inner nut. The laminated rubber bearing fixing structure according to claim 3 or 4, wherein the anchor bolt is screwed onto the inner nut.

Images