JP2917735B2 - How to install bridge supports - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, in bridge construction for constructing a main girder supported on a pier via a rubber bearing. It relates to the improvement of the installation method of the bridge bearing that was given.

[0002]

2. Description of the Related Art When a concrete main girder is constructed on a large span pier via rubber bearings, the amount of movement of the main girder at a bearing point due to creep and drying shrinkage of the main girder becomes large. The bearing structure is designed in anticipation. In other words, prior to placing the main girder concrete, an appropriate shear deformation is given to the rubber bearing in advance, and the initial deformation of the main girder due to subsequent creep or drying shrinkage reduces the shear deformation of the rubber bearing, The device is designed to minimize the shear deformation of the rubber bearing when the movement stops.

However, when designing the bearing structure, it is necessary to perform a complicated calculation to calculate the initial displacement of the main girder to minimize the shear deformation of the bearing. Has a problem that the main girder does not always move as calculated.

On the other hand, a method has been developed for correcting the distortion of the bearing caused by the amount of movement of the main girder after the initial movement. Specifically, a base plate is fixed to an apex of the pier by an anchor bolt or the like, and a rubber bearing (a structure in which a rubber member is sandwiched between an upper plate and a lower plate) is temporarily fixed thereon. The lower plate of the rubber bearing is superimposed on the base plate and positioned, and the lower plate is temporarily fixed to the base plate by an appropriate mechanism, and a formwork of a main girder is temporarily provided on the upper plate of the rubber bearing to concrete. Cast in. Then, release the temporary fixing of the lower plate, install a horizontal jack between the pier and the lower plate,
The lower plate is displaced by a predetermined distance in the main girder moving direction by the horizontal jack. Since the upper plate is fixed to the main girder, when the lower plate is displaced by the jack, the rubber bearing is sheared. When the lower plate is displaced and positioned at a predetermined position, the lower plate is fixed to the base plate by welding.

[0005]

However, such a conventional method of installing a rubber bearing has the following problems. Since the lower plate is displaced along the base plate by the horizontal jack, a large vertical load of the main girder is applied between the lower plate and the base plate, so that a very large frictional force acts between the two plates. Since the lower plate is displaced against this frictional force,
Large capacity jacks are required. In particular, since the friction coefficient between the two plates is not stable, a large-capacity jack had to be prepared on the assumption that the friction coefficient was the largest. In addition, the mount for installing a large-capacity horizontal jack had to be large, and the work of installing and removing it was troublesome.

Further, since the lower plate of the rubber bearing is finally welded and fixed to the base plate, the welding operation must be performed in a narrow space between the pier top and the main girder, and the workability is poor. Otherwise, there was a fear that the rubber bearing was damaged by the welding spark. Furthermore, it was very difficult to correct the position of the lower plate after welding.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to perform complicated calculations at the stage of designing a bearing, do not require a large-capacity jack, and perform welding work. It is an object of the present invention to provide a method of installing a bridge bearing which can provide the above-described shearing deformation without any difficulty in operation.

[0008]

In order to achieve the above object, the present invention is to fix a base plate on a pier top,
An intermediate plate is slidably disposed on the base plate, a rubber bearing having a rubber member between the upper and lower plates is disposed on the intermediate plate, and a lower plate of the rubber bearing is temporarily fixed to the pier top. At the same time, a formwork of the main girder is installed on the upper plate of the rubber bearing, and concrete is poured into the formwork. Then, the lower plate and the intermediate plate are fixed, and the lower plate and the pier are temporarily Release the fixation, install a vertical jack between the pier top and the main girder to reduce the vertical load acting on the rubber bearing, and provide a horizontal push screw mechanism provided between the base plate and the lower plate. The lower plate and the intermediate plate are integrally displaced in the main girder direction by a predetermined distance, and the intermediate plate is fixed to the bridge pier apex at a position after the displacement by a bolt. It is intended to.

[0009]

Since the vertical load applied to the rubber bearing by the vertical jack is reduced, the frictional force between the base plate and the intermediate plate is reduced, and the intermediate plate can be easily connected to the intermediate plate by a simple horizontal push screw mechanism. The lower plate can be displaced along the base plate.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The main steps of a method of installing a rubber bearing according to an embodiment of the present invention are shown in FIGS. First, Figure 1
As shown in (1), the base plate 3 is fixed to the top of the pier 1 with the anchor bolts 2. The installation portion of the base plate 3 is recessed by the thickness of the plate, and the upper surface of the plate is set so as to be flush with the peripheral pier top surface. The base plate 3 is formed with a bolt hole used for an operation described later.

Next, as shown in FIG. 2, the intermediate plate 4 is overlaid on the base plate 3. The intermediate plate 4 is narrower and longer than the base plate 3. Both plates are subjected to a surface treatment so as to reduce friction between the base plate 3 and the intermediate plate 4. further,
Two lateral push screw mechanisms including a jack base 8 and a jack screw 9 are set on the base plate 3 on both sides of the intermediate plate 4. A pair of claws are formed at both ends of the lower surface of the jack base 8 so as to hold both ends of the base plate 3, and the thickness of a portion placed on the upper surface of the base plate 3 is almost the same as the thickness of the intermediate plate 4. is there. The end of the jack base 8 that protrudes larger than the base plate 3 is bent in an L-shape, and a jack screw 9 is horizontally mounted in a screw hole in that portion.

After setting the intermediate plate 4 and the two lateral push screw mechanisms on the base plate 3 as described above, the rubber bearing 5 is further installed thereon. As is well known, the rubber bearing 5 has a rubber member serving as a bearing main body interposed between the lower plate 6 and the upper plate 7. The lower plate 6 is substantially the same size as the base plate 3, and is placed on the intermediate plate 4 and the jack base 8.
At 0, the lower plate 6 is temporarily fixed to the base plate 3. In addition, a formwork of the main girder 20 is set on the upper plate 7 and concrete is poured into the formwork to construct the main girder 20.

After the main girder 20 is completed, the lower plate 6 is fixed to the intermediate plate 4 by another bolt 11, and the temporary fixing bolt 10 is removed. As a result,
The lower plate 6 and the intermediate plate 4 of the rubber bearing 5 are integrated, and both plates 6 and 4 are slidable on the base plate 3.

Further, although not shown in FIG.
A vertical jack is provided between the top of the main girder 20 and the lower surface of the main girder 20, and the vertical load applied to the rubber bearing 5 by the jack is reduced to reduce the frictional force generated between the intermediate plate 4 and the base plate 3. With the frictional force reduced in this way, the end face of the lower plate 6 is pushed in the direction of the main girder (the direction of the arrow in the drawing) by rotating the jack screw 9 of the lateral push screw mechanism, and the lower plate 6 is interposed with the lower plate 6 The plate 4 is displaced rightward in the figure to a predetermined position. As described above, when the integrated lower plate 6 and intermediate plate 4 are displaced in the direction of the arrow, the upper plate 7 is fixed to the main girder 20, so that the main body portion of the rubber bearing 5 is sheared and its distortion is adjusted. Is done.

Then, with the intermediate plate 4 displaced to a predetermined position, as shown in FIG. 4, the intermediate plate 4 is fixed to the pier 1 with bolts 12 and the vertical jack is removed.

The lateral push screw mechanism can be removed after use and used repeatedly at another place. In this case, it is desirable to fill the gap after removing the screw mechanism with an appropriate member.

[0017]

As described above in detail, according to the present invention, since the vertical jack is used to reduce the vertical load applied to the bearing, when the capacity of the vertical jack is set, there is an instability between the plates. There is no need to take into account any factors of friction, and even a relatively small-capacity vertical jack can reduce the friction between the plates and move the lower plate with a simple horizontal push screw mechanism.

Further, the work of installing a vertical jack between the pier and the main girder is easier than the installation of the horizontal jack in the conventional method, and is easy to remove. Furthermore, since the intermediate plate is fixed to the pier with bolts instead of the conventional welding fixation, fixing work in narrow places is easy, there is no risk of damaging the rubber bearing with welding sparks, and it is compared to changing the fixing position Can be easily dealt with.

[Brief description of the drawings]

FIG. 1 is a front view and a plan view showing a first installation process of a rubber bearing according to one embodiment of the present invention.

FIGS. 2A and 2B are a front view and a plan view showing a second installation process of a rubber bearing according to one embodiment of the present invention.

3A and 3B are a front view and a plan view showing a third installation step of a rubber bearing according to one embodiment of the present invention.

FIG. 4 is a front view and a plan view showing a fourth installation process of the rubber bearing according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bridge pier 2 Anchor bolt 3 Base plate 4 Intermediate plate 5 Rubber bearing 6 Lower plate 7 Upper plate 8 Jack base (lateral push screw mechanism) 9 Jack screw (horizontal push screw mechanism) 10 bolt 11 bolt 12 bolt 20 main girder

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E01D 19/04

Claims (1)

(57) [Claims] 1. A base plate is fixed to the apex of a pier, an intermediate plate is slidably disposed on the base plate, and a rubber bearing having a rubber member between upper and lower plates is disposed on the intermediate plate. A lower plate of the rubber bearing is temporarily fixed to the top of the pier, and a main girder formwork is installed on the upper plate of the rubber support, and concrete is poured into the formwork. While fixing the temporary fixing of the lower plate and the pier, a vertical jack is installed between the pier top and the main girder to reduce the vertical load acting on the rubber bearing, and the base plate and The lower plate and the intermediate plate are integrally displaced by a predetermined distance in the main girder direction by a horizontal push screw mechanism attached between the lower plate and the position after the displacement. A method for installing a bridge bearing, wherein the intermediate plate is fixed to the top of the pier with bolts.