JP2929923B2 - 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 foregoing, the present invention has been made in view of the above-mentioned conventional problems, and a large propulsion reaction force for a large-capacity jack can be easily obtained on a bridge substructure to which an anchor plate is attached. It is an object of the present invention to provide a structure for correcting a shear deformation of a seismic isolation bearing, which can easily correct the shear deformation of the seismic isolation 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 repair structure for correcting the shear deformation occurring, the bridges lower structure on the anchor plate such the lower plate of the seismic isolation bearings to be mounted slidably in the shear deformation direction against the seismic isolation An engagement frame that locks on one side in the shear deformation direction with the support interposed therebetween, the engagement frame having a lower frame that stands upward from the lower plate and a locking claw that abuts and locks on a side end surface of the lower plate. A gantry, an upper gantry protruding downward from the lower surface of the bridge girder on the other side in the shear deformation direction with the seismic isolation bearing interposed therebetween, and a substantially horizontal erection between the upper gantry and the lower gantry. Telescopic device In shear deformation repair structure of seismic isolation bearing, characterized by comprising a telescopic device which expands and contracts in the shear deformation direction Te.

[0009]

According to the structure for correcting the shear deformation of the seismic isolation bearing of the present invention, the correction of the shear deformation is performed by the lower gantry standing upright from the lower plate of the engaging gantry locked and fixed to the lower plate and the lower portion from the bridge girder. The lower plate is slid by contracting an expansion / contraction device provided between the upper frame and the upper pedestal. In other words, the propulsion reaction force for such sliding movement can be easily obtained from the bridge girder having a large weight via the upper gantry, and the telescopic device is mounted substantially horizontally, and is parallel to the sliding direction of the lower plate. By the expansion and contraction, the expansion and contraction drive of the expansion and contraction device is efficiently used as a driving force for the slide movement.

[0010]

Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, a shear deformation correcting structure 10 of a base-isolated bearing according to this embodiment
Interposed between the bridge girder 31 and the concrete bridge girder 31
For example, when shear deformation occurs due to the movement of the bridge girder 31 due to drying shrinkage or creep of concrete, etc., the seismic isolation bearing 12 that supports It is used to give the bearing 12 a shear deformation in advance.

Here, the seismic isolation bearing 12 comprises a bearing body 13 made of an elastic material such as laminated rubber, an upper plate 14 attached to the upper surface thereof, and a lower plate 15 attached to the lower surface thereof. The seismic isolation bearing 12 is interposed between the pier 30 and the bridge girder 31 by fixing the lower plate 15 to the lower surface of the bridge girder 31 and mounting and fixing the lower plate 15 on the anchor plate 11 installed on the pier 30. The impact load generated between the pier 30 and the bridge girder 31 is reduced by the above-described method.

The shear deformation correcting structure 10 is an engaging base that is locked to the lower plate 15 of the seismic isolation bearing 12 placed on the anchor plate 11 and stands upright from the lower plate 15. An engagement gantry 18 having a locking claw 17 that comes into contact with the side end surfaces of the lower gantry 16 and the lower plate 15, an upper gantry 19 projecting downward from the lower surface of the bridge girder 31, and an upper gantry 19 and the lower gantry 16 And a telescopic device 20 installed substantially horizontally between them.

The anchor plate 11 is a plate member made of steel similar to a known one, and is connected to the pier 30 via an anchor bolt buried in the concrete of the pier 30.
Is firmly fixed. Further, the surface of the anchor plate 11 is subjected to a surface treatment by, for example, galvanizing or the like so as to be slippery and rust-resistant.

The lower plate 15 of the seismic isolation bearing 12 placed on the anchor plate 11 is provided with the seismic isolation bearing 1.
On one side in the shear deformation direction X with the two interposed therebetween, the engaging base 18 is locked. The engagement base 18 surrounds the lower outer periphery of the support main body 13 so as to surround the lower plate 1.
A lower frame 16 having a U-shape in horizontal cross section composed of three side walls erected on the upper surface 5, and is integrally provided on a side wall of the lower frame 16 opposed to the shear deformation direction X and projects rearward and downward. It has a locking claw 17 that extends to contact the side end surface of the lower plate 15. Then, the engagement base 18 is firmly fixed on the lower plate 15 with, for example, bolts or the like.

On the other hand, an upper base 19 is provided on the other side of the vibration isolating bearing 12 in the shear deformation direction X. The upper gantry 19 is composed of three side walls protruding downward from the lower surface of the bridge girder 31 so as to surround the upper outer periphery of the support main body 13 like the lower gantry 16, for example, by welding or the like to the lower surface of the bridge girder 31. It is firmly fixed. In addition, since the upper gantry 19 is fixed to the bridge girder with a predetermined width in the shear deformation direction X, particularly on both side walls, the seismic isolation bearing 1 is provided by a later-described telescopic jack 20.
2 corrects the moment applied to the fixed portion by the expansion and contraction of the jack 20 and the propulsion reaction force for the expansion and contraction jack 20
Transmit to 1.

Then, with the seismic isolation bearing 12 interposed therebetween,
A telescopic jack 20 that expands and contracts in the shear deformation direction X is installed substantially horizontally between the lower gantry 16 and the upper gantry 19 arranged on both sides of the seismic isolation bearing 12. The telescopic jack 20 is actuated by, for example, hydraulic pressure to obtain a propulsion reaction force from the bridge girder 31 via the upper gantry 19, draws the engaging gantry 18, and moves the lower plate 15 through the locking claw 17 in the shear deformation direction. Slide to X. Since the telescopic jack 20 is installed substantially horizontally between the upper base 19 and the lower base 16 erected or protruded above and below the seismic isolation bearing 12, it expands and contracts in parallel with the sliding direction of the lower plate 15. Thereby, the expansion / contraction drive of the expansion / contraction jack 20 is efficiently used as a driving force for the slide movement.

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, when the seismic isolation bearing 12 is subjected to a pre-operation or a correction work, the engagement pedestal 18 and the upper pedestal 1
9 and the telescopic jack 20 are installed. As shown in FIG. 1, when the bridge girder 31 is moved by the shrinkage of the bridge girder 31 due to drying shrinkage or creep, etc., the seismic isolation bearing 12 undergoes shear deformation. Modify the deformation. At this time, the locking claw 17 of the engagement base 18 is
1 and draws the lower plate 15 in the direction of the arrow in FIG.
5 is slid to the position shown in FIG. Here, in this embodiment, the lower plate 15
Also, a surface treatment such as galvanizing is performed, which enables a smooth sliding movement between the anchor plate 11 and the lower plate 15, and makes it possible to easily correct the shear deformation of the seismic isolation bearing 12. it can.

In this embodiment, 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 present invention is not limited to this. For example, by applying a shear deformation in the opposite direction to the seismic isolation bearing 12 in advance and fixing the seismic isolation bearing 12, it can be used to cope with shear deformation that occurs later.

[0019]

As described in detail above, 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 bearing is adjusted by the telescopic device to correct the shear deformation of the seismic isolation bearing. When sliding, a large propulsion reaction force can be easily obtained from a heavy bridge girder through the upper gantry provided at the lower part of the bridge girder. The shear deformation of the seismic isolation bearing can be easily corrected by using the drive efficiently as a propulsion force.

[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 shows a situation in which the shear deformation of a base-isolated bearing is corrected by a shear deformation correcting structure.

[Explanation of symbols]

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

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 substructure such as a pier and an abutment and a bridge girder, the anchor being provided on the bridge substructure. plugs for the plate
An engaging base that is locked on a lower plate of a seismic isolation bearing slidably mounted in a shear deformation direction on one side in a shear deformation direction with the seismic isolation bearing interposed therebetween, and is erected upward from the lower plate. An engagement base having a locking claw that abuts against a lower end and a side end surface of the lower plate; and an engagement base protruding downward from a lower surface of the bridge girder on the other side in the shear deformation direction across the seismic isolation bearing. And a telescopic device erected substantially horizontally between the upper gantry and the lower gantry, the telescopic device extending and contracting in the shear deformation direction. Correction structure.