JP2842192B2 - Shear deformation correction structure of base-isolated bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for correcting a shear deformation of a seismic isolation bearing, and more particularly to a method for correcting a shear deformation occurring in a seismic isolation bearing installed between a bridge substructure such as a pier or an abutment and a bridge girder. Correction structure for seismic isolation bearings used for the purpose.

[0002]

2. Description of the Related Art When constructing a bridge, bearings are provided between bridge substructures such as piers and abutments and bridge girders. In other words, this bearing plays the role of transmitting the deformation and load of the bridge superstructure such as the bridge girder to the lower trench structure without difficulty and following the deformation of the lower structure so as not to affect the superstructure as much as possible. For example, pin bearings, roller bearings, rubber bearings and the like are known. Also, various types of so-called seismic isolation bearings have been developed for efficiently mitigating shock loads such as seismic force. Such a seismic isolation bearing is composed of an elastic body such as a laminated rubber, and an upper plate and a lower plate which are attached with the elastic body interposed therebetween.The upper plate is attached to the upper structure, and the lower plate is attached to the lower groove. The impact load is reduced by the action of an elastic body interposed between the upper structure and the lower groove structure.

On the other hand, such seismic isolation bearings may cause shear deformation due to temperature expansion and contraction of the bridge girder installed thereon, and particularly when the bridge girder is made of concrete,
After the concrete is cast, the bridge girder moves horizontally due to the effects of drying shrinkage and creep, which causes large shear deformation, which may impair the seismic isolation function of the elastic body such as laminated rubber.

As a method for addressing such a problem,
A method has been proposed in which the amount of shear deformation is calculated when designing the structure of the bearing and the displacement is given to the bearing in advance, but it is difficult to accurately grasp the actual travel of the bridge girder, The work of installing the bridge girder while giving displacement to the bearing in advance becomes difficult.

On the other hand, a method has been developed in which, after the bridge girder moves, the shear deformation of the bearing caused by the movement amount is directly corrected on site. In other words, this method involves temporarily fixing a seismic isolation bearing on an anchor plate installed on a bridge substructure such as a pier, and moving the bridge girder above it by drying shrinkage or creep of concrete. If shear deformation occurs on the bearing, release the temporary fixation, slide the lower plate of the seismic isolation bearing along the anchor plate using a horizontal jack, etc., remove the shear deformation, and weld or fix in this state The anchor plate and the base isolation bearing are permanently fixed by bolts.

[0006]

However, the conventional method for directly correcting the above-mentioned shear deformation on site has the following problems. In other words, a large vertical load is applied to the seismic isolation bearing by the weight of the bridge girder,
As a result, an extremely large frictional force acts between the lower plate of the seismic isolation bearing and the anchor plate. Therefore, a large-capacity jack is required to slide the lower plate against such a large frictional force, but a strong base for obtaining the propulsion reaction force of the large-capacity jack is provided on a narrow bridge lower part. There was a problem that the work of attaching to the upper part of the structure was troublesome.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and a propulsion reaction force for a jack can be obtained with a simple structure on a bridge substructure to which an anchor plate is attached, and a seismic isolation bearing is provided. It is an object of the present invention to provide a structure for correcting a shear deformation of a base-isolated bearing which can easily correct the shear deformation of the bearing.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and its gist is to provide a seismic isolation bearing installed between a bridge substructure such as a pier or an abutment and a bridge girder. A shear deformation correcting structure for correcting a generated shear deformation, comprising: a side surface of a seismic isolation bearing mounted on an anchor plate installed on an upper surface of the bridge substructure adjacent to a side thereof. A telescopic device installed diagonally,
Upper locking means for pivotally attaching one end of the telescopic device to the end of the upper plate of the seismic isolation bearing in one of the shear deformation directions sandwiching the seismic isolation bearing, and the other end of the telescopic device And a lower locking means for axially attaching the seismic isolation bearing to the end of the lower plate of the seismic isolation bearing in the other direction of shear deformation sandwiching the seismic isolation bearing. .

In the above description, the structure in which the end of the telescopic device is axially mounted on the upper plate or the lower plate by the upper locking means or the lower locking means is directly mounted on the upper plate or the lower plate. In addition to the above-mentioned case, the present invention also includes a configuration in which the shaft is attached via a mounting member that is engaged with an end of the upper plate or the lower plate.

[0010]

According to the structure for correcting the shear deformation of the seismic isolation bearing of the present invention, the shear deformation is corrected before and after the seismic isolation bearing with the seismic isolation bearing interposed therebetween. This is performed by extending or contracting a telescopic device erected on a diagonal line on the side surface of the seismic isolation bearing, and sliding the lower plate. That is, the telescopic device is pivotally attached to the upper plate and the lower plate via the upper locking means and the lower locking means, and the reaction force for the telescopic drive of the telescopic device is directly obtained from the bridge girder via the upper plate. The expansion and contraction device can be installed diagonally across the shear deformation direction of the seismic isolation bearing, so the expansion and contraction device can be extended or contracted while pressing the upper and lower plates against the bridge girder and the bridge substructure, or By contracting the telescopic device so that the distance between the end of the lower plate and the end of the lower plate is minimized,
The shear deformation of the seismic isolation bearing is easily corrected.

[0011]

Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a shear deformation correcting structure 10 of a base-isolated bearing according to this embodiment, which is interposed between a pier 30 and a concrete bridge girder 31 to correct the shear deformation of a base-isolated bearing 12 supporting the bridge girder 31. In order to show the situation installed on the seismic isolation bearing 12,
Is a state in which the bridge girder 31 has moved in the direction of the arrow in the figure due to, for example, drying shrinkage or creep of concrete, and shear deformation has occurred.

Here, the seismic isolation bearing 12 comprises a bearing body 13 made of an elastic material such as laminated rubber, for example, and an upper plate 14 attached to the upper surface thereof and a lower plate 15 attached to the lower surface thereof. The lower plate 15 is firmly fixed to the lower surface of the bridge girder 31 and the lower plate 15 is
By mounting and fixing on the anchor plate 11 installed at 0, the seismic isolation bearing 12 is interposed between the pier 30 and the bridge girder 31, and the shock generated between the pier 30 and the bridge girder 31 due to seismic force or the like. This is to relieve a heavy load.

The shear deformation correcting structure 10 according to this embodiment includes a telescopic jack 20 as a telescopic device installed on the side of the seismic isolation bearing 12 and one end of the telescopic jack 20. An upper pin structure 16 serving as an upper locking means which is axially attached to an end of the upper plate 14 behind the shear deformation direction (the direction of the arrow in FIG. 12) of the upper 12 and the other end of the telescopic jack 20 are connected to the seismic isolation bearing 12. And a lower pin structure 17 serving as lower locking means for axially attaching to the end of the lower plate 15 in the front of the shear deformation direction.

The telescopic jack 20 is driven, for example, by hydraulic pressure, and includes a jack portion 20a and a jack portion 20a.
Rod portions 20b, 20b extending from both ends of the rod portion 20b. Pin holes 2 for attaching upper and lower pin bolts 16 ', 17' are formed in the ends of the rod portions 20b, 20b.
1 and 22 are respectively formed. On the other hand, the upper and lower pin bolts 16 'and 17' are bolt members projecting outward from the side surfaces of the upper plate 14 and the lower plate 15, and are provided integrally with the upper and lower plates 14 and 15, respectively. Can be

The telescopic jack 20 is connected to the rod 2
0b, 20b through the pin holes 21, 22 drilled,
The upper and lower pin bolts 16 ′, 17 ′ are axially mounted at both ends so that they are installed adjacent to the side of the seismic isolation bearing 12 and diagonally on the side surfaces thereof. That is, one end of the telescopic jack 20 is located on the end of the upper plate 14 behind the seismic isolation bearing 12 in the shear deformation direction, and the other end is located on the front side in the shear deformation direction with the seismic isolation bearing 12 therebetween. By locking to the end of the lower plate 15, respectively, it is installed on the diagonal line of the side surface of the seismic isolation bearing 12.

The anchor plate 11 on which the seismic isolation bearing 12 is mounted is a steel plate member similar to a known one, and is provided via an anchor bolt 32 buried and installed in the concrete of the pier 30. It is firmly fixed to the pier 30. In the present embodiment, the surface of the anchor plate 11 is subjected to a surface treatment by, for example, zinc plating so that the surface is easy to slip and rust-resistant. On the other hand, the lower plate 15 is also subjected to a surface treatment such as galvanization, so that the anchor plate 11 and the lower plate 15 can slide smoothly.

The shear deformation correcting structure 1 having the above configuration
According to 0, the shear deformation of the seismic isolation bearing 12 is corrected as follows. That is, upper and lower pin bolts 16 ′ and 17 ′ are integrally provided on the upper plate 14 and the lower plate 15 of the seismic isolation bearing 12 in advance or at the time of performing a repair work, and these are drilled at both ends of the telescopic jack 20. The telescopic jack 20 is erected and installed by locking through the provided pin holes 21 and 22. Then, by extending the telescopic jack 20, the lower plate 15 is slid to the position directly below the upper plate 14 so that the lateral shape of the support body 13 becomes rectangular, and the seismic isolation bearing 12 is moved.
To remove shear deformation. At this time, the telescopic jack 20
Is directly locked to the upper plate 14 via the upper pin structure 16, so that the propulsion reaction force for sliding the lower plate 15 can be obtained directly from the bridge girder 31 to which the upper plate 14 is fixed. Since the telescopic jack 20 is mounted diagonally on the side of the seismic isolation bearing, the upper and lower plates 14 and 15 are respectively connected to the bridge girder 3.
The shear deformation of the seismic isolation bearing 12 is easily corrected by extending the telescopic jack 20 while pressing the lower surface of the base 1 and the upper surface of the pier 30.

FIG. 2 shows another embodiment of the upper locking means and the lower locking means constituting the shear deformation correcting structure 10 of the seismic isolation bearing of this embodiment. That is,
According to the locking means and the lower locking means, the upper plate 14 and the lower plate 15 are surrounded by outer frame plates 40 and 41 as attachment members which are locked and fixed to the upper and lower plates 14 and 15. Both ends of the telescopic jack 20 are pivotally attached to ends of the upper plate 14 or the lower plate 15.

That is, the outer frame plates 40, 41
Is, as shown in FIG.
Opening 43 large enough to accommodate lower plates 14 and 15
In the outer frame plate 40 attached to the upper plate 14, the outer frame plate 41 attached to the lower plate 15 is provided at the rear end in the shear deformation direction. The portion has an upper pin bolt 16 'or a lower pin bolt 17' protruding laterally, similar to that shown in FIG.

The outer frame plates 40 and 41 are temporarily fixed to the upper plate 14 and the lower plate 15 by temporary fixing bolts 42. That is, the outer frame plate 40,
At the side of 41, mounting holes 44 into which the temporary fixing bolts 42 are inserted are formed so as to penetrate the outer frame plate, and the mounting holes 44 on the side surfaces of the upper plate 14 and the lower plate 15. A bolt hole 45 into which the temporary fixing bolt 42 is screwed is provided at a position where the outer frame plates 40 and 41 are installed so as to surround the upper plate 14 or the lower plate 15. In this case, the temporary fixing bolt 42 is attached to the outer frame plate 4.
The outer frame plates 40 and 41 are inserted into the mounting holes 44 of the outer frame plates 40 and 41 and screwed into the bolt holes 45.
Are temporarily fixed to the upper plate 14 and the lower plate 15.

Then, the outer frame plates 40, 4 having the above configuration
According to the shear deformation correcting structure 10 provided with 1, the shear deformation of the seismic isolation bearing 12 is corrected as follows. That is, the outer frame plates 40 and 41 as the upper and lower portion locking means are temporarily fixed to the upper and lower plates 14 and 15 of the seismic isolation bearing 12 in advance or at the time of the correction work by the above-described means. The telescopic jack 20 is erected between the upper and lower pin bolts 16 ′, 17 ′ of the frame plates 40, 41, and the upper and lower outer frame plates 40, 41 are pressed against the lower surface of the bridge girder 31 and the lower surface of the pier 30.
Is extended to slide the lower plate 15. Thereby, the upper plate 1 of the seismic isolation bearing 12
As a result, the lower plate 15 is pushed out to a position directly below the position 4, and the shear deformation of the seismic isolation bearing 12 is removed.

In each of the above embodiments, after the seismic isolation bearing 12 undergoes shear deformation due to drying shrinkage of the bridge girder 31 or the like, the shear deformation correcting structure 10 is used to correct the shear deformation. The seismic isolation bearing 12 is given a shear deformation in the opposite direction in advance by extending the expansion jack 20 in the direction opposite to the direction in which the bridge girder 31 is expected to move due to drying shrinkage of the concrete. By fixing the seismic isolation bearing 12 in this way, it can also be used to cope with shear deformation that occurs later.

Furthermore, in the present embodiment, the seismic isolation bearing is modified by extending the telescopic jack. However, the present invention is not limited to this.
The deformation can also be corrected by attaching the telescopic jack 20 on a diagonal line crossing the diagonal line to which the zero is attached and contracting the telescopic jack 20.

[0024]

As described above in detail, according to the structure for correcting the shear deformation of the seismic isolation bearing of the present invention, the lower plate of the seismic isolation support is corrected by the telescopic device in order to correct the shear deformation of the seismic isolation bearing. When sliding, the expansion and contraction means
Since it is attached to the upper plate and the lower plate of the seismic isolation bearing, the reaction force for the expansion and contraction drive of the expansion and contraction device can be obtained directly from the upper plate with a simple configuration.
The telescopic jacks are mounted diagonally on the sides of the seismic isolation bearings, so the telescopic device is extended while pressing the upper and lower plates against the bridge girder and the bridge undercarriage, or the ends of the upper and lower plates are The shear deformation of the seismic isolation bearing can be easily corrected by extending and retracting the telescopic jack so that the tied distance becomes the shortest.

[Brief description of the drawings]

FIG. 1 is a side view showing a shear deformation correcting structure according to an embodiment of the present invention, showing a state where a shear deformation has occurred in a seismic isolation bearing installed between a pier and a bridge girder.

FIG. 2 is a side view showing another embodiment of the shear deformation correcting structure of the present invention.

FIG. 3 is a plan view showing an outer frame plate constituting a shear deformation correcting structure according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shear deformation correction structure 11 Anchor plate 12 Seismic isolation bearing 15 Lower plate 16 Lower stand 17 Engagement claw 18 Engagement stand 19 Upper stand 20 Telescopic jack 30 Bridge pier 31 Bridge girder

Claims (1)

(57) [Claims] 1. A shear deformation correcting structure for correcting a shear deformation occurring in a seismic isolation bearing installed between a bridge pier, an abutment, etc., and a bridge substructure, and a bridge girder, wherein a shear deformation correction structure is provided on an upper surface of the bridge substructure. A telescopic device is installed adjacent to the side of the seismic isolation bearing placed on the installed anchor plate and diagonally on the side surface thereof, and one end of the telescopic device is attached to the seismic isolation bearing. Upper locking means for pivotally attaching to the end of the upper plate of the seismic isolation bearing in one of the sandwiched shear deformation directions, and the other end of the telescopic device in the other of the shear deformation directions sandwiching the seismic isolation bearing. A structure for correcting a shear deformation of a seismic isolation bearing, characterized by comprising a lower locking means which is attached to an end of a lower plate of the seismic isolation bearing.