JPH0378884B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a forced sliding type rubber bearing device used for supporting concrete bridge girders.

[Prior art]

Conventionally, as a sliding rubber bearing device for supporting a bridge girder, a fixed rubber bearing is equipped with a hard layer fixed to the upper surface of the soft rubber layer and a lower sliding bearing plate fixed to the upper surface of the hard layer. A structure is known in which a movable support body is fixed to the upper part of a support structure such as an abutment, and has an upper sliding support plate placed on the lower sliding support plate, and is fixed to a bridge girder (for example, (Refer to Utility Model Publication No. 51-32259).

As the lower sliding support plate and the upper sliding support plate, for example, tetrafluoroethylene or stainless steel plates are used, and the friction coefficient between the tetrafluoroethylene plates is 0.05 to 0.08, and the friction coefficient between the tetrafluoroethylene plates and the stainless steel plate is The friction coefficient is 0.07-0.09. In addition, when constructing a bridge girder using a sliding rubber bearing device, it is easy for foreign matter such as dirt to adhere to the upper surface of the lower sliding bearing plate and the lower surface of the upper sliding bearing plate during the construction period. When a bridge girder is constructed on top of a sliding rubber bearing device with foreign matter such as dirt trapped between the sliding bearing plate and the upper sliding bearing plate, the coefficient of friction between the lower sliding bearing plate and the upper sliding bearing plate is It will be larger than the above value.

In the case of a sliding rubber bearing device, when the bridge girder contracts due to drying shrinkage, creep, shrinkage due to prestress, etc., the rubber layer first undergoes shear deformation toward the middle of the bridge girder, and then the movable bearing slides on the fixed rubber bearing. do.

[Problem that the invention seeks to solve]

The amount of shear deformation of the rubber layer before the movable support slides is proportional to the coefficient of friction between the lower sliding support plate and the upper sliding support plate. For example, if a load of 100 tons is acting on a rubber bearing device combined with a slide,
The coefficient of friction between the lower sliding bearing plate and the upper sliding bearing plate is
0.05, when the movable support starts sliding, the shearing force acting on the rubber layer is 5 tons. When a shear force of 5 tons is applied, the rubber layer is sheared by about 12-15% of its thickness. Further, when foreign matter such as dirt is trapped between the lower sliding support plate and the upper sliding support plate and the coefficient of friction increases, the shear deformation of the rubber layer becomes even larger.

On the other hand, if the ratio of the amount of shear deformation to the thickness of the rubber layer becomes too large, the durability of the rubber material will be shortened, so it is necessary to increase the thickness of the rubber layer in proportion to the amount of shear deformation. However, increasing the thickness of the rubber layer increases the amount of rubber material used, which is uneconomical.

[Purpose and structure of the invention]

The object of the present invention is to provide a forced sliding rubber bearing device that can advantageously solve the above-mentioned problems. A fixed rubber bearing 4 comprising an upper metal plate 2 and a lower sliding bearing plate 3 fixed to the upper surface of the upper metal plate 2 is placed on the upper part of the support structure 5, and the lower sliding bearing plate In the sliding rubber bearing device in which a movable support body 7 having an upper sliding support plate 6 slidably placed on the upper metal plate 3 is fixed to the lower part of a concrete bridge girder 8, the bridge girder intermediate part in the upper metal plate 2 This forced sliding rubber bearing device is characterized in that a stopper 10 having a locking portion 9 facing the side surface is detachably fixed to a support structure 5.

〔Example〕

Next, the present invention will be explained in detail using illustrated examples.

1 to 5 show a first embodiment of the present invention, in which a lower metal plate 11 made of a steel plate is shown.
A rubber layer 1 and an upper metal plate 2 made of a steel plate are placed on the top surface of the
and a lower sliding support plate 3 made of tetrafluoroethylene are sequentially laminated and fixed to form a fixed rubber support 4.
The lower metal plate 11 of the fixed rubber support 4 is placed on top of a support structure 5 such as a concrete abutment or pier, and a plurality of anchor bolts embedded in the support structure 5 are installed. 12
Fixed by

An upper sliding support plate 6 made of a stainless steel plate is fixed to the lower surface of a movable support body 13 made of a steel plate to constitute a movable support body 7, and the lower ends of a plurality of anchor bars 14 are welded to the upper surface of the movable support body 13. etc., each anchor bar 14 is embedded in the concrete bridge girder 8, the upper surface of the movable support 7 is brought into contact with the lower surface of the bridge girder 8, and the upper sliding bearing plate 6 is fixed to the lower sliding bearing plate 3. It is placed.

A plurality of steel lateral pressure bearing members 15 are arranged at intervals in the bridge girder width direction and fixed by welding to the upper surface of the end of the bridge girder intermediate side of the lower metal plate 11, and the bridge girder intermediate side of the upper metal plate 2 A plurality of steel stoppers 10 having locking portions 9 facing each other in close proximity to the side surfaces thereof are placed on the lower metal plate 11 between the lateral pressure bearing member 15 and the rubber layer 1, and The rubber layer side portion of the seat plate 16 of 15 is fixed by a plurality of bolts 17 inserted through the seat plate 16 and screwed to the lower metal plate 11, and the end of the seat plate 16 is fixed to the lateral pressure support member 15. is in contact with.

Concrete bridge girder 8 suffers from drying shrinkage, creep,
As it contracts due to prestress etc., the rubber layer 1
As shown in FIG. 4, the side surface of the upper metal plate 2 on the intermediate side of the bridge girder abuts against the locking part 9 of the stopper 10, causing further shear deformation. is prevented, and the bridge girder 8 contracts in this state.

After the shrinkage of the bridge girder 8 due to drying shrinkage, creep, prestress, etc., that is, the shrinkage not caused by a drop in temperature, is completely or almost completely completed, the stopper 10 is removed and the state shown in FIG. 5 is reached.

6 to 9 show a second embodiment of the present invention, in which an upper metal plate 2 is integrally fixed to the upper surface of a rubber layer 1.
A lower sliding support plate 3 made of tetrafluoroethylene is integrally fixed to the upper surface to constitute a fixed rubber support 4, and a rubber layer 1 in the fixed rubber support 4 is formed.
is placed on the upper surface of the concrete support structure 5, and the steel support plate 18 on which the stopper 10 is placed is
placed on the support structure 5 and the support structure 5
The lateral pressure support member 15 is fixed to the support plate 18 by welding, and the seat plate 16 of the stopper 10 is fixed to the support plate 18 by bolts 17. is the same as in the first embodiment.

In the case of the second embodiment as well, after the contraction of the bridge girder 8 that is not caused by a drop in temperature is completely or almost completely completed, the stopper 10 is removed and the state shown in FIG. 9 is reached.

When carrying out this invention, FIGS. 10 and 1
As shown in FIG.
A mounting plate, which is bent and continuous on both sides of the stopper 10, may be fixed to the side surface of the stopper 10 with screws 21.

〔Effect of the invention〕

According to the invention, the fixed rubber support 4 comprising the upper metal plate 2 fixed to the upper surface of the rubber layer 1 and the lower sliding support plate 3 fixed to the upper surface of the upper metal plate 2 is a support structure. A movable support 7 is fixed to the lower part of the concrete bridge girder 8, and has an upper sliding support plate 6 placed on the upper part of the body 5 and slidably placed on the lower sliding support plate 3. In the sliding rubber bearing device, a stopper 10 having a locking portion 9 facing the side surface of the intermediate side of the bridge girder in the upper metal plate 2 is detachably fixed to the support structure 5, so that dry shrinkage of the bridge girder is prevented. The upper metal plate 2 is directly or indirectly engaged with the locking part 9 of the stopper 10 until the contraction due to creep and prestress is almost completed, so that the rubber layer 1 is positioned at the middle side in the longitudinal direction of the bridge girder. Therefore, even if the bridge girder 8 contracts due to a drop in temperature after the stopper 10 is removed after drying shrinkage, creep, and prestress shrinkage of the bridge girder has finished, the rubber layer Since the amount of shear deformation of 1 is extremely small, the thickness of the rubber layer can be made thinner, and the stopper 10 that only prevents the upper metal plate 2 from moving toward the middle side of the bridge girder in the fixed rubber support 4 can be installed in the support structure. The structure is simple as it only needs to be provided removably to the body 5. Therefore, the rubber bearing device combined with the slide can be manufactured at low cost, and the stopper 10
After removing the rubber layer 1, the rubber layer 1 can be freely sheared and deformed in accordance with the expansion and contraction of the bridge girder 8 due to temperature changes.

[Brief explanation of drawings]

1 to 5 show a forced sliding rubber bearing device according to a first embodiment of the present invention, in which FIG. Figure 2 is an enlarged partial longitudinal side view of a portion of the same, Figure 3 is a plan view showing the relationship between the fixed rubber support and the stopper, and Figure 4 shows the upper metal plate of the fixed rubber support attached to the stopper. FIG. 5 is a partially longitudinal side view showing the abutted state, and FIG. 5 is a partially longitudinal side view showing the rubber bearing device combined with a slide after the stopper is removed. 6 to 9 show a forced sliding rubber bearing device according to a second embodiment of the present invention, in which FIG. 6 is a partially longitudinal side view showing the state immediately after the bridge girder is constructed; FIG. 7 is a longitudinal front view, FIG. 8 is a plan view showing the relationship between the fixed rubber support and the stopper, and FIG. 9 is a partially longitudinal side view showing the slide rubber bearing device after the stopper has been removed. Fig. 10 is a partially longitudinal side view showing a state in which a spacer is attached to a locking part of a stopper in a rubber bearing device combined with a slide;
FIG. 1 is a plan view showing a state in which a spacer is attached to a locking portion of a stopper. 1 is a rubber layer, 2 is an upper metal plate, 3 is a lower sliding support plate, 4 is a fixed rubber support, 5 is a support structure, 6
is the upper sliding support plate, 7 is the movable support, 8 is the bridge girder,
9 is a locking portion, 10 is a stopper, 11 is a lower metal plate, 12 is an anchor bolt, 13 is a movable support body, 15 is a steel lateral pressure support member, 17 is a bolt, 1
8 is a steel support plate, 19 is an anchor bolt.

Claims (1)

[Claims] 1 A fixed rubber support 4 comprising an upper metal plate 2 fixed to the upper surface of the rubber layer 1 and a lower sliding support plate 3 fixed to the upper surface of the upper metal plate 2 is mounted on the upper part of the support structure 5. placed on the lower sliding support plate 3
In a sliding rubber bearing device in which a movable support 7 having an upper sliding support plate 6 that is slidably placed on a concrete bridge girder 8 is fixed to the lower part of a concrete bridge girder 8, the middle side of the bridge girder in the upper metal plate 2 A stopper 10 having a locking portion 9 facing the side surface of the stopper 10
is removably fixed to the support structure 5. A forced sliding rubber bearing device.