JP4176928B2 - Sliding bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sliding bearing that is used in an extrusion method in which a part or all of a concrete bridge girder is manufactured at a girder manufacturing position and then moved to a predetermined position, and supports the bridge girder so as to be slidable.
[0002]
[Prior art]
One method of erection of concrete bridges is the extrusion method. In this method, part or all of a bridge girder is manufactured at a girder production position, and this is pushed out to a predetermined position and installed. And as one method of pushing out the bridge girder, there is a method of sliding the bridge girder by supporting the bridge girder on a plurality of bearings and applying a propulsive force. As the support for supporting the bridge girder, a slide support processed so that the upper surface can be easily slid is used, and is replaced with a permanent use after erection is completed.
[0003]
Extrusion erection as described above is performed in the following steps.
As shown in FIG. 5, this construction method is a construction method suitable for erection of the bridge girder 102 so as to straddle the position where it is necessary to reduce the work on the railway line 101 or the like as much as possible. Produce behind. In the case shown in FIG. 5, a girder production yard is provided on the pier 103 and the temporary support column 104.
[0004]
As shown in FIG. 6B, the bridge girder 102 manufactured in the girder manufacturing yard is pulled by the jack 106 supported on the pier 103 via the tension member 105 and moves on the pier 103 and the temporary support column 104. . The sliding support 110 when pushing out the bridge girder 102 is provided under the web of the bridge girder 102 as shown in FIG. 6A, and is installed avoiding the position where the permanent support 111 is provided.
Note that a steel hand girder 107 is attached to the end of the bridge girder 102 in order to reduce a bending moment generated when the bridge girder is extended.
[0005]
The bridge girder 102 continued to be pulled by the jack 106 by changing the fixing position of the tension material 105 as the extrusion proceeded, and the hand girder 107 reached the existing girder 108 as shown in FIG. Thereafter, the hand girder 107 is further pushed out while being supported by the girder 108.
Then, after the bridge girder 102 to be pushed out moves to a predetermined position, as shown in FIG. 5 (c), concrete 109 is placed between the existing girder 108 and prestress is introduced to connect with the existing girder 108. To do. Thereby, the extrusion construction of the bridge girder 102 is completed.
[0006]
Generally, the sliding bearing used in the extrusion method as described above is made of concrete in a block shape, and a sliding surface such as stainless steel is attached to the upper surface, and there is a sliding plate between this upper surface and the lower surface of the girder. Is inserted.
[0007]
[Problems to be solved by the invention]
However, the conventional sliding bearings have the following problems.
When the bridge girder is pushed out, a deflection angle occurs on the bridge girder on the sliding bearing. In particular, as shown in FIG. 5B, when the bridge girder 102 is greatly extended from the pier 103a, the deflection angle of the bridge girder on the pier 103a is increased. Further, when the hand girders are supported by the existing girders 108 that are cantilevered, the existing girders 108 may bend to cause a large deflection angle of the bridge girders 102 on the pier 103a.
In general, it is difficult for the sliding bearing to have a structure that absorbs the rotation angle. When a large deflection angle is generated in the bridge girder, the weight of the bridge girder is unbalanced before and after the sliding bearing.
[0008]
On the other hand, at the time of extrusion, since the bridge girder is supported in the absence of the cross beam, as shown in FIG. 6, it is necessary to place the sliding support directly under the web, and further avoid the position where the permanent support 111 is provided. In order to support the load, the shape of the sliding bearing must be long in the direction of the bridge axis. Thus, when it becomes a long shape in the axial direction of the bridge girder, the influence of the above-mentioned offset load becomes remarkably large. And when a big unloading load arises, there exists a possibility that a sliding bearing may be damaged locally.
[0009]
Also, the bottom surface of the bridge girder supported by the sliding bearing is difficult to finish completely flat and has some unevenness. For this reason, as the portion supported by the sliding bearing moves during extrusion, the reaction force of the sliding bearing may fluctuate greatly and may differ greatly from the designed reaction force. In addition, the reaction force may vary greatly between the left and right fulcrum of the bridge girder.
As described above, the reaction force fluctuates irregularly, which may cause excessive stress on the bridge girder.
[0010]
The present invention has been made in view of the above-described problems, and the purpose of the present invention is to deviate reaction force due to the deflection angle of the bridge girder, change in reaction force due to manufacturing error of the bridge girder, etc. It is to provide a sliding bearing that can push out and move the bridge girder safely and reliably.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 is a sliding bearing in which the bridge girder to be extruded and supported is supported from below and the upper surface of the bridge girder slides.
A lower steel plate having a steel plate material placed almost horizontally on the foundation structure or the erected structure, and a side restraint portion raised over the entire periphery at the periphery of the steel plate material; A rubber plate material for support that is divided into a plurality of portions and arranged at intervals in the side restraint portion, and has a flat sliding surface at the top, a flat bottom surface, and a bottom portion in the side restraint portion. It is fitted to be able to move up and down almost in the whole area, and has an upper collar placed on the rubber plate material, and the rubber plate material is divided into a plurality of sizes and intervals when arranged, When a predetermined load in the vertical direction is applied to the upper collar, the upper steel sheet is determined to be filled in a space surrounded by the steel plate material, the inner side surface of the lateral restraint portion, and the bottom surface of the upper collar. It provides sliding bearings.
[0012]
In such a sliding support, a lower rod is placed on a foundation structure such as an abutment or an abutment, or a temporary structure such as a temporary support or a support, and the upper rod is supported via a rubber plate material. A bridge girder is supported on the upper rod, and is slid on the upper surface of the upper rod and pushed out to a predetermined position. At this time, the upper arm supports the bridge girder in an elastically depressed state due to the deformation of the rubber plate material. Therefore, even if the deflection angle of the bridge girder occurs, the reaction force bias in the sliding bearing accompanying this is slightly suppressed. The bridge girder will be supported by the whole sliding bearing. This prevents a large reaction force from being generated locally, and ensures the safety of the sliding bearing.
[0013]
Also, if there is some unevenness on the bottom surface of the bridge girder, or if there is a manufacturing error on the bottom surface of the bridge girder, the excessive reaction force locally due to the deformation of the rubber plate or the reaction force bias of the left and right sliding bearings Is alleviated. Further, the reaction force at the time of extrusion can be prevented from greatly fluctuating from the calculation reaction force (design at the time of installation) due to the manufacturing error of the bottom surface of the bridge girder. As a result, it is possible to eliminate the risk of crushing of the sliding bearing at the time of extrusion erection and the possibility of excessive stress being generated in the bridge girder.
[0014]
In addition, since the rubber plate material is divided into a plurality of portions and arranged at intervals, the distribution of the bearing stress of the rubber plate material becomes nearly equal, and a predetermined deformation can be reliably generated.
In addition, when a propulsive force is applied to the bridge girder and it slides on the upper gutter, a horizontal force acts on the upper gutter due to friction, but the bottom is fitted inside the side restraint part of the lower gutter. Therefore, the movement in the horizontal direction is restrained by the lower arm.
[0015]
Further, in such a sliding bearing, when the weight of the bridge girder acts on the upper heel, the upper heel sinks and the rubber plate material is deformed so as to swell laterally. And when the side surface of this rubber plate material is brought into contact with the inner side surface of the side restraint portion or the side surface of another rubber plate material arranged adjacent thereto, the bottom surface of the upper collar, the upper surface of the lower collar, and the side restraint portion It will be in the state where the rubber board material was filled up in the space enclosed by the inner surface of. As a result, the rubber plate material is restrained from further deformation, and the upper plate is less likely to sink. That is, when a predetermined load or more is applied, deformation hardly occurs, and excessive settling of the upper eyelid is prevented. Further, along with this, the compression failure of the rubber plate material hardly occurs, and it becomes possible to support a large reaction force.
[0016]
The invention according to claim 2 is a sliding support in which the bridge girder to be extruded and supported is supported from below and the upper surface of the bridge girder slides, and is mounted substantially horizontally on the foundation structure or the erected structure. A steel plate and a lower rod having a lateral restraint portion that is raised all around the periphery of the steel plate material, and is divided into a plurality of and arranged at intervals in the lateral constraint portion of the lower cage A rubber plate material for support, and a flat sliding surface at the top and a flat bottom surface, and the bottom portion is fitted into almost the entire area in the side restraint portion so that it can be moved up and down. And a sliding bearing provided with a step for regulating the amount of subsidence of the upper saddle at the inner lower portion of the side restraint portion .
[0017]
In such a sliding bearing, when the bridge girder sinks due to the weight of the bridge girder and the amount of settlement exceeds a predetermined amount, the bottom surface of the upper collar comes into contact with the horizontal surface of the step and the settlement is restrained.
Therefore, excessive deformation is prevented even when an excessive load is applied to the sliding bearing.
At the same time, the side portion of the rubber plate is constrained by the vertical surface of the step, and compression failure is prevented in a state where the space is filled between the bottom surface of the upper collar and the upper surface of the lower collar.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the invention according to the present application will be described with reference to the drawings.
FIG. 1 is a schematic perspective view showing a sliding bearing which is an embodiment of the present invention. 2 and 3 are cross-sectional views.
This sliding bearing supports the bridge girder so that it can slide when the concrete bridge girder is pushed out and installed, and is mounted on a foundation structure such as a pier or an abutment or a temporary structure such as a temporary strut 1 The main part is composed of a rubber plate 2 divided and arranged on the lower plate 1 and an upper plate 3 supported on the rubber plate 2.
[0019]
The lower gutter 1 includes a rectangular steel plate material 11 that is long in the direction in which the bridge girder 51 is pushed out, and a side restraint portion 12 that is raised upward at the peripheral edge of the steel plate material 11. This side restraint part 12 is formed by welding and joining a steel member, is provided in the whole circumference | surroundings of the lower collar 1, and surrounds the range where the rubber plate material 2 is arrange | positioned. As shown in FIG. 3, a step-like step 12 a is provided at the inner lower portion of the side restraint portion 12, and the horizontal surface of the step 12 a faces the bottom surface of the upper bowl 3.
[0020]
Moreover, the latching | locking part 13 with the upper collar 3 is provided on the side restraint part 12 in the front end side of the extrusion direction of a bridge girder. The function of the locking portion 13 will be described later.
[0021]
The rubber plate 2 is a plate made of chloroprene rubber, cut into a square, and arranged in the longitudinal direction of the lower collar 1.
[0022]
The upper plate 3 is welded and joined by combining steel plates, and includes a bottom plate 31 that is disposed substantially horizontally, a top plate 32 that is disposed substantially parallel to the bottom plate 31, and the bottom plate 31 and the top plate 32. And a vertical plate 33 in the vertical direction.
[0023]
The bottom plate 31 has a flat bottom surface, and the planar shape corresponds to the inner surface of the side restraint portion 12 of the lower collar 1. Thereby, it is possible to fit the bottom portion of the upper collar inside the lateral restraint portion 12 with the inner surface and a slight gap surface over the entire circumference.
A plurality of the vertical plates 33 are arranged in the pushing direction of the bridge girder 51 and in a direction perpendicular thereto, and are assembled in a lattice shape, supporting the weight of the bridge girder 51 acting on the upper plate 32, and from the bottom plate 31 to the rubber A load is transmitted to the lower rod 1 through the plate material 2.
[0024]
The upper plate 32 is rounded at the top side and the rear side in the pushing direction of the bridge girder 51 so that the sliding plate 4 can be inserted between the upper plate 32 and the bridge girder 51 when the bridge girder 51 is pushed out. I have to.
Further, a stainless steel plate (not shown) having a thickness of 1 mm is attached to the upper surface of the upper plate 32 so that the sliding plate 4 can easily slide.
[0025]
The sliding plate 4 is formed by alternately laminating hard rubber and steel plates and bonding a fluororesin plate to the lowermost layer, and reduces friction between the fluororesin plate and the upper surface of the stainless steel plate. In addition, sliding is easily generated even when a large load is applied.
[0026]
Such a sliding bearing acts as follows when the tip of the bridge girder that is pushed out and moves reaches the sliding bearing and slides forward on the upper arm.
When the front end of the bridge girder reaches the rear end of the upper girder, the sliding plate 4 is inserted between the bottom surface of the bridge girder 51 and the upper surface of the upper girder 3 from the cutting portion of the upper plate 32, and the sliding plate 4 together with the bridge girder 51 is inserted. Slide on the upper arm 3. When the tip of the bridge girder 51 is placed on a part of the rear side of the sliding bearing, a reaction force is generated only on the rear side, and the front end of the upper rod 3 tries to jump up. The locking portion 13 is locked to the upper surface of the bottom plate 31 of the upper collar 3 to prevent the front end of the upper collar 3 from jumping up. Further, the rear end of the upper collar 3 is brought into contact with the horizontal surface of the step 12a provided in the side restraint portion 12 so that excessive deformation does not occur.
[0027]
Thereafter, when the pushing out of the bridge girder 51 proceeds, the bridge girder 51 is placed over the entire sliding support that is long in the pushing direction, and slides on the upper surface of the upper rod 3 and moves.
At this time, the sliding plate 4 is sequentially inserted between the bridge girder 51 and the upper eaves 3 at the rear end, and is collected at the front end side and used repeatedly.
[0028]
Further, the upper collar 3 is abutted against the lateral restraining portion 12 of the lower collar 1 and is restrained from moving at the time of extrusion, but the rubber plate 2 is deformed and sinks. As shown in FIG. 4, the rubber plate 2 is filled in a space surrounded by the bottom surface of the upper collar 3, the upper surface of the lower collar 1, and the side restraint portion 12 when the upper collar 3 sinks by a predetermined amount. Thus, further lateral bulging is restricted, yield strength is increased, and collapse is prevented.
Further, when the deformation further progresses, the bottom surface of the upper collar 3 comes into contact with the horizontal surface of the step 12a inside the side restraint portion, and further sinking is restrained.
[0029]
As described above, when the pushing movement of the bridge girder 51 supported by the sliding bearing advances, the distribution of the bending moment acting on the bridge girder 51 always moves, and a deflection angle may be generated on the sliding bearing. However, the upper collar 3 is supported via the rubber plate 2 and the deformation of the rubber plate 2 reduces the reaction force bias in the sliding bearing. Even if there are irregularities or manufacturing errors on the bottom surface of the bridge girder 51, the reaction force bias between the left and right bearings and the reaction force distribution in the bearing are reduced, and the reaction force acting on the sliding bearing is Large variations with design values are avoided.
[0030]
【The invention's effect】
As described above, in the sliding bearing of the present invention, when a concrete bridge girder is extruded and installed, even if there is a deflection angle on the bearing due to deformation of the bridge girder, irregularities on the bottom face of the bridge girder or manufacturing errors, the bearing caused by this. In addition to reducing the reaction force bias in the interior or between the left and right bearings, avoid the fluctuation of the sliding bearing reaction force from the calculated reaction force that is expected to occur during installation. Can do.
As a result, even if the bearing area of the sliding bearing is increased, the reaction force is less biased, and a sliding bearing capable of supporting a large load can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a sliding bearing according to an embodiment of the present invention.
2 is an elevational sectional view and a plan sectional view of the sliding bearing shown in FIG. 1. FIG.
FIG. 3 is a vertical sectional view of the sliding bearing shown in FIG. 1 in a direction perpendicular to the pushing direction of the bridge beam.
4 is a cross-sectional view showing a state in which the upper collar of the sliding bearing shown in FIG. 1 has been sunk. FIG.
FIG. 5 is a diagram showing a construction procedure when a concrete bridge girder is extruded and installed.
FIGS. 6A and 6B are a front view and a side view showing an installation state of a sliding bearing when a concrete bridge girder is extruded and installed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lower rod 2 Rubber plate material 3 Upper rod 4 Sliding plate 11 Steel plate material 12 Side restraint part 13 Locking part 31 Bottom plate 32 Upper board 33 Vertical board 51 Bridge pier 52 Bridge girder

Claims (2)

A sliding bearing on which the bridge girder is supported from below while the bridge girder slides on the upper surface,
A steel plate material placed almost horizontally on the foundation structure or the erection structure, and a lower armature having side restraints raised over the entire circumference on the periphery of the steel plate material,
In the side restraint portion of the lower collar, a rubber plate material for support that is divided into a plurality and arranged at intervals,
An upper ridge that has a flat sliding surface at the top, has a flat bottom surface, and that the bottom portion is fitted so as to be able to move up and down almost all over the side restraint portion, and is placed on the rubber plate material, With
The rubber plate material is divided into a plurality of dimensions and intervals when arranged, and when a predetermined load in the vertical direction acts on the upper collar, the steel plate material and the inner side surface of the side restraint portion A sliding bearing, characterized in that the sliding bearing is defined so as to be filled in a space surrounded by the bottom surface of the upper collar. A sliding bearing on which the bridge girder is supported from below while the bridge girder slides on the upper surface,
A steel plate material placed almost horizontally on the foundation structure or the erection structure, and a lower armature having side restraints raised over the entire circumference on the periphery of the steel plate material,
In the side restraint portion of the lower collar, a rubber plate material for support that is divided into a plurality and arranged at intervals,
An upper ridge that has a flat sliding surface at the top, has a flat bottom surface, and that the bottom portion is fitted so as to be able to move up and down almost all over the side restraint portion, and is placed on the rubber plate material, With
A sliding bearing , characterized in that a step for regulating the amount of subsidence of the upper eyelid is provided at an inner lower portion of the side restraint portion.

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