JP3883659B2 - Box girder support - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a box girder support, and more particularly to a support having a plurality of divided support parts, and particularly an easy work when exchanging the support for repair.
[0002]
[Prior art]
Bridges such as roads are provided between superstructures including box girders, substructures including piers or abutments (hereinafter abbreviated as piers), and between these superstructures and substructures. It consists of a bearing that relaxes and absorbs vibrations. The bearing has a sole plate connected to the box girder of the superstructure, a rectangular base plate attached to the bridge pier of the substructure, etc., and a bearing such as a rubber bearing mounted between them. In particular, the four corners of the base plate are fixed to the pier by fixing them with anchor bolts.
[0003]
FIG. 3 is a view for explaining a conventional type of support in which a box girder is supported by a plurality of support portions arranged in the width direction of the bridge in the above-described bridge pier or the like, and is a perspective view seen from above. In the illustrated example, each of the two supports (1) has one support part (2), and each support part (2) is fixed on the base plate (3). The base plate (3) has its four corners fixed to the piers (21) by anchor bolts (5a, 5b), and the two support portions (2) provided on the corners (11) I support it.
[0004]
As can be seen from FIG. 3, the sides facing each other in the bridge width direction of each base plate (3) are located below the box girder (11) (in the downward projection region) and are secured by two inner anchor bolts (5a). It is fixed to the pier etc. (21) at the apex. On the other hand, the opposite side portion extends to the outside (outside the lower projection area) from the box girder (11), and the apex angle portion of the extended portion is fixed by two anchor bolts (5b). ing. Normally, when building a new bridge or the like, since the box girder (11) is constructed after assembling the support (1) on the upper surface of the pier (21) or the like, the inner anchor bolt (5a) is attached to the pier or the like ( When placing in 21), the box girder (11) is not disturbed.
[0005]
By the way, in general, the service life of a bearing is designed for bridges and other facilities and is not expected to be replaced. However, it is necessary to replace the bearing when a large stress is applied due to an earthquake, etc. It may become. However, when exchanging the above-described bearings of an existing bridge in this way, the repair (restoration) work becomes extremely troublesome work with the same bearing structure as the existing structure.
[0006]
In such a support, since each support part is arranged below the box girder and supports the box girder, at least a part of the anchor bolt for fixing each support part to the bridge pier is located below the box girder. Therefore, when the structure described above is restored as it is, the distance between the lower surface of the box girder (11) and the upper surface of the bridge pier (21) is very small. In order to cope with this, the anchor bolt insertion hole (work hole) is opened at the bottom of the box girder and the inner anchor bolt (5a) is driven using this through hole. Must be set up.
[0007]
In other words, when exchanging and restoring this type of support of an existing bridge, the support replacement work is generally performed by lifting it with a large jack that can support the superstructure. The distance between the lower surface of the box girder and the upper surface of the bridge pier is very narrow. Therefore, in this type of bearing structure in which the anchor bolt is located below the box girder as described above, the inner anchor bolt is driven in the usual way. Could not do. As a result, as described above, a work hole is conventionally required, and an operator enters the box girder to form a work hole at the bottom of the box girder, and the inner anchor bolt is driven using this work hole. I had to. In particular, when drilling holes and when carrying anchor bolts, workers must enter and work inside the box girder, and it is quite difficult to handle anchor bolts that are heavy and have a certain length in a narrow space inside the box girder. This is a difficult task, and the exchange of the bearings is complicated and takes a great burden on the operator and requires a considerable work period. In addition, the above-mentioned repair method also has a problem that the strength of the box girder is reduced as a result of opening a hole in the box girder.
[0008]
[Problems to be solved by the invention]
As described above, when the existing bridge support replacement work is restored with exactly the same structure, the work is complicated, a heavy burden is placed on the operator, and a construction period is required. It has been pointed out that the strength of the box girder is reduced by making a hole in the box.
[0009]
The present invention has been made in view of the above problems, and the purpose of the present invention is to easily replace and reinforce work when repairing a broken or obsolete bearing, shorten the construction period, and solve the above problems. The object is to provide a structural support.
[0010]
[Means for Solving the Problems]
The present invention includes a long plate-like base plate (3) that is fixed to an abutment / abutment and that extends at the both ends in the longitudinal direction of the box girder to be supported, and extends to the outside. A plurality of support portions (2) fixed in the lower projection region of the box girder in the longitudinal direction, and a base plate (3) in a portion extending out of the lower projection region at both longitudinal ends of the base plate (3) The box girder support has attachment means (5) including anchor bolts for fixing only to the pier / abutment.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view of the support (1) of the present invention as viewed from above at a box girder height, and FIG. 2 is a front view of the same support. This support (1) is composed of two support portions (2), a base plate (3) and attachment means (5), and in particular, the attachment means (5) is provided outside the lower projection area of the box girder to be supported. Yes.
[0012]
In the support (1), two support parts (2) are fixed to a single long base plate (3), and this base plate (3) serves as a mounting means (5) at its longitudinal end. Each is fixed to a bridge pier (21) by four anchor bolts. In this case, anchor bolts (attachment means) are not required below the box girder (11) in the prescribed engagement state with the piers (21), and all anchor bolts to be driven are in the lower projection area of the box girder. Since it is located outside, the placing operation can be easily performed.
[0013]
The base plate (3) is made of long plate-like iron or other metal and extends to the outside of the lower projection area of the box girder to be supported at both ends in the longitudinal direction when it is fixed to a pier or abutment at a specified position. It is set to the length to be issued. And four through-holes for anchor bolts as attachment means (5) for fixing to the pier / abutment are provided outside the lower projection region at both longitudinal ends of the base plate (3). Corresponding to the through hole, a box opening hole for an anchor bolt is provided on the pier side. Further, two support portions (2) are fixedly arranged in the longitudinal direction in the lower projection region of the box girder on the upper surface side of the base plate.
[0014]
The length of the long base plate (3) in the width direction is determined according to the dimensions of the support, and the length in the longitudinal direction is the box girder at both ends when this base plate is installed under the box girder. It is determined so that the anchor bolt (5) can be attached to the extended portion. The number of anchor bolts (5) is determined in relation to the length and diameter depending on the design conditions (reaction force, mobility, etc.) of the support portion.
[0015]
The number of anchor bolts (5) for fixing one end of the base plate (3) is determined depending on the length and diameter of each anchor bolt so as to maintain the strength that can withstand the reaction force applied to both supports. For example, when the reaction force applied to the bearing is set to 220 tf, sufficient strength can be obtained by using four anchor bolts having a length of about 650 mm and a diameter of about 50 mm to fix one end of the base plate. .
[0016]
The procedure for replacing the bearing when the bearing (1) of the embodiment is used will be briefly described. The bearing replacement work is performed by lifting it with a large jack or the like that can support the superstructure as in the conventional case. Hereinafter, (A) First, the outer anchor bolt (5) is temporarily installed. The installation position is outside the lower projection area of the box girder, and the long anchor bolt (5) is not obstructed by the box girder (11). It can be easily placed on the pier (21). Needless to say, there is no need to cast the inner anchor bolt by making a hole in the bottom of the box girder, and naturally the strength of the box girder is not impaired.
[0017]
Subsequently, (B) after the base plate (2) is set at a specified position, and a nut is screwed to the tip of the anchor bolt (5) protruding through the through hole described above and securely fixed to the pier (21). Return the superstructure and place it. The order of the operations (A) and (B) can be reversed. After the positioning is completed, the anchor bolt (5) and the seat surface are driven.
[0018]
As described above, when the support (1) of the embodiment is used, when exchanging the support, the anchor bolt (5) can be easily placed on the bridge pier (21) without being obstructed by the box girder (11). In addition, the number of man-hours can be reduced without the need for opening the box girder bottom.
[0019]
A sole plate is disposed on the upper surface of the rubber bearing as an example, and a long base plate is disposed on the lower surface, and the rubber bearing, the base plate and the sole plate are respectively locked by a shear key. Of course, locking means or fixing means other than the shear key may be used. Note that side blocks for suppressing lateral displacement of the rubber bearing with respect to the bridge shaft are provided on both lateral sides of the illustrated rubber bearing with respect to the bridge shaft. It is fixed by.
[0020]
Supporting the present invention approval is shall be fixed plurality of bearing a pier or the like by the same in the longitudinal direction both end portions of the plurality of anchor bolts to fix onto the box girder in the lower projected area in elongated base plate Therefore, the bearing portion of the present invention can use, for example, a steel bearing instead of a rubber bearing depending on the purpose. Furthermore, it goes without saying that those appropriately using auxiliary members (such as side blocks) that can be provided on the base plate of the present invention also belong to the scope of the present invention.
[0021]
In other words, the support of the present invention is extremely effective when used for replacement purposes, and there is no inconvenience even when it is used when building a new bridge. Since the inner anchor bolt can be driven on the bridge pier and the like without being disturbed by the beam, it is appropriate to use the conventional bearing from the viewpoint of saving the base plate material, and it is not necessary to use the bearing of the present invention. .
[0022]
【The invention's effect】
Bearing of the present invention, is fixed to the box girder in the lower projected area a plurality of bearing on the same long base plate, the outer portion of the lower projection region of the extension portion or box girder of the base plate with anchor bolts Since it is configured to be fixed to a bridge pier or the like, it is possible to drive the anchor bolt at a predetermined position without being obstructed by the box girder when the support is exchanged. That is, it is not necessary to make a hole at the bottom of the box girder as in the prior art, and the replacement work can be simplified. This reduces the burden on the operator, shortens the work period, and reduces the cost. At the same time, the strength reduction of the box girder due to the bottom opening can be avoided.
[Brief description of the drawings]
FIG. 1 is a perspective view of a support portion of the present invention.
FIG. 2 is a front view of a support portion of the present invention.
FIG. 3 is a perspective view showing a conventional structure when a box girder is supported by two support portions.
[Explanation of symbols]
1 Support 2 Support 3 Base Plate 4 Sole Plate 5 Anchor Bolt 6 Side Block 11 Box Girder 21 Bridge Pier / Abutment

Claims (1)

And is fixed to the pier, abutments its longitudinal both end portions extending to an elongated plate-like base plate beneath the projection area of the box girder to be supported to the outer (3), the longitudinal direction at once on said base plate A plurality of support portions (2) fixed in the lower projection area of the box girder, and only the base plate (3) of the portion extending out of the lower projection area at both longitudinal ends of the base plate (3) A box girder support having attachment means (5) including anchor bolts for fixing to the abutment.

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