JP3662854B2 - How to replace bridge bearings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for exchanging bridge supports, and to construction for replacing an existing steel bearing with a rubber bearing.
[0002]
[Prior art]
Conventionally, when newly installing a bridge support or replacing an existing support, a saddle mortar is placed on the upper surface of the abutment, and the support is installed on the mortar after it reaches a predetermined strength. It was.
[0003]
In recent years, maintenance work for existing bridges has become widespread, and the number of bridge supports has increased. In particular, a technique for replacing an existing steel bearing with a rubber bearing to improve vibration characteristics and earthquake resistance characteristics of a vehicle has been widely used. Conventionally, when a bearing is newly installed or replaced, it is common to first construct a saddle mortar on which the bearing is placed, and then install the bearing thereon. Also, in the case of existing bridges, there is a problem that the clearance between the existing girders and the abutment upper surface is small and workability is very bad. There was a problem that voids and the like were formed on the surface.
[0004]
[Problems to be solved by the invention]
When the present inventors install a bridge support, particularly when replacing an existing bridge support with a new support, there is a problem that the above workability is poor or a gap is generated between the support and the girder. We have developed a technology that does not have such problems, and can be constructed quickly, accurately and in a short construction period. The present invention aims to provide such a new technology.
[0005]
[Means for Solving the Problems]
The present invention has been made to solve the above-mentioned problems, and technical means thereof are as follows. That is, in the present invention, when replacing the bridge support, jack up the existing girder and remove the existing support, then place the new support on the abutment via the spring on the lower surface, and install the new support with the spring. While pushing upward, jack down the existing girder to the specified height, assemble the scorpion formwork of the new bearing on the abutment, place the mortar in the scorpion formwork, and remove the jack after mortar hardening This is a characteristic method for replacing bridge bearings.
[0006]
In this case, the jack should be placed on a bracket attached to the side of the abutment. If the gap between the abutment and the girder is small and the workability will be hindered, the upper surface of the abutment will be removed. Therefore, it is preferable to place the new bearing after removing the existing bearing and adjusting the top surface of the abutment with mortar.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a side view of a support portion of an existing bridge, and is an explanatory view showing an initial stage of the method of the present invention. The existing girder 1 is placed on the abutment 2 via the support 3. In exchanging the support 3, the existing girder 1 is jacked up. The jack 12 is placed on a bracket 11 attached to the side surface of the abutment 2. A hole for embedding the anchor bolt 14 for attaching the bracket 11 is formed, and the bracket 11 is attached. A hydraulic jack 12 is placed on the bracket 11 and the girder 1 is jacked up. As a result, a working space is secured, and the load on the support is replaced with a jack to facilitate the removal of the existing support. When the gap between the beam 1 and the abutment 2 is narrow and difficult to work, the upper surface 13 of the abutment 2 is suspended by a core drilling hole or the like. This suspending operation can be easily performed from the side surface of the abutment using a drilling machine or the like.
[0008]
After jacking up the girder 1, if necessary, hang concrete around the support and remove the existing support 3. After removal, the concave portion of the removal part on the upper surface of the abutment is refined, and a non-shrink mortar is placed to flatten the upper surface of the abutment.
[0009]
FIG. 1 shows technical means in the latter part of the embodiment of the present invention. The new bearing 5 is placed on a lower surface of the existing girder 1 that has been jacked up (substantially the same position as the position of the bearing before replacement) via a spring 6. The spring 6 is biased so as to push the new bearing 5 upward, and presses the new bearing 5 against the bottom surface 4 of the beam 1. The dimensions, number of springs, number of springs used, arrangement, etc. of the spring 6 are determined by design according to the size, weight, etc. of the new bearing. The spring 6 functions to push up the new bearing so as to be in close contact with a predetermined portion of the existing girder.
[0010]
Next, the jack 12 is jacked down to a predetermined height, and the girder 1 and the support 5 are positioned at the proper positions. The scorpion mold 7 of the new bearing is assembled around the support 5 on the abutment, and mortar is placed in the scorpion mold 7. The mortar is preferably a non-shrink mortar. The spring 6 is embedded in the mortar. After the mortar has hardened and has reached a predetermined design strength, the hydraulic jack 12 is opened and removed to complete the construction.
[0011]
FIG. 3 is a flowchart showing the process of the present invention. After the anchor drilling hole 21 of the bracket supporting the jack, the bracket installation 22 is performed, and the hydraulic jack set 23 is performed thereon. Next, the existing girder is jacked up 24, the support portion is suspended 25, and the existing support removal 26 is performed. A non-shrink mortar placement 27 is performed on the upper surface of the abutment of the bearing removal site, and a new bearing installation 28 is performed. At this time, a spring is interposed on the lower surface of the new bearing. Next, the entire process of the present invention is completed by jacking down 29 to place the girders and new bearings in their proper positions and removing the hydraulic jack 32 after the saddle mold installation 30 and the saddle mortar placement 31. To do.
[0012]
【The invention's effect】
According to the present invention, for example, when replacing a steel bearing of an existing bridge with a rubber bearing, the existing girder is raised to a predetermined height while jacking up the existing girder, removing the existing bearing, and lifting the rubber bearing with a spring. Jacking down, assembling the scorpion formwork and setting up the mortar makes it easy to replace the bearing, and the new bearing can be accurately placed in the correct position without creating a gap in the contact surface between the mortar and the bearing. It can be installed and has the excellent effect of greatly contributing to the rationalization of the replacement work of the bearing.
[Brief description of the drawings]
FIG. 1 is a front view of a support portion for explaining an embodiment.
FIG. 2 is a side view of a support portion for explaining an embodiment.
FIG. 3 is a flowchart of the embodiment.
[Explanation of symbols]
1 Girder 2 Abutment 3 Existing support 4 Bottom surface 5 New support 6 Spring 7 Mold 11 Bracket 12 Jack 13 Upper surface 14 Anchor bolt 21 Anchor hole drilling hole 22 Bracket installation 23 Jack set 24 Jack up 25 Support part is removed 26 Existing support removal 27 Mortar Placing 28 Support installation 29 Jack down 30 Formwork installation 31 Mortar placement 32 Jack removal

Claims (3)

When replacing the bridge support, jack up the existing girder, remove the existing support, place the new support on the abutment via a spring on the lower surface of the new support, and urge the new support upward with the spring While the existing girder is jacked down to the specified height, the stool formwork of the new bearing is assembled on the abutment, the mortar is placed in the stool formwork, and the jack is removed after the mortar is hardened. Exchange method. 2. The method for replacing a bridge support according to claim 1, wherein the jack is placed on a bracket attached to a side surface of the abutment. 3. The method of replacing a bridge support according to claim 1 or 2, wherein the existing support is removed by holding the upper surface of the abutment, the upper surface of the abutment is adjusted with a mortar, and then the new support is placed.

Images