JP3579786B2 - Bridge expansion joints - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bridge expansion joint.
[0002]
[Prior art]
As an expansion joint for bridges, for example, there is one as shown in FIG. 3, and as shown in this figure, grooves 10, 11 extending at right angles to the bridge axis direction of the bridge H are formed on the upper and lower surfaces. The elastic band 1 having a substantially constant thickness is formed, and the elastic band between the adjacent upper surface side groove 10 and lower surface side groove 11 serves as a shear deformation portion 12. In this expansion joint, as shown in FIG. 3, a load receiving plate 2 buried in a portion between the grooves 11, 11 in the elastic band 1 is bridged between the bridges H, H and the elastic band. 1 is installed in such a manner that an end portion side of the groove 10 closer to the endmost end is fixed to the bridge H by an anchor bolt (not shown) so that the wheel load is received by the load receiving plate 2 and a change in environmental temperature is caused. The expansion and contraction of the bridge H is absorbed by the deformation of the shear deformation portion 12.
[0003]
However, in the above expansion joint, there is a problem that the elastic portion on the load receiving plate 2 has a large thickness as shown in FIG.
[0004]
As a method for solving the above problem, it is conceivable to arrange a narrow thick steel plate 9 on the load receiving plate 2 as shown in FIG. 4 or to make the entire load receiving plate 2 thick. In the method, the weight of the expansion joint increases, and in particular, in the latter method, the shear deformation rate of the shear deformation portion increases.
[0005]
[Problems to be solved by the invention]
In view of the above, an object of the present invention is to provide an expansion joint for a bridge in which (1) the weight is not increased, (2) the sinking due to the wheel load is small, and (3) the shear deformation rate of the shear deformation portion is small. .
[0006]
[Means for Solving the Problems]
(Invention of claim 1)
In the expansion joint for bridges of the present invention, grooves 10, 11 extending at right angles to the bridge axis direction of the bridge are formed on the upper and lower surfaces, and shear deformation between adjacent grooves 10 on the upper surface and grooves 11 on the lower surface is performed. The elastic band-shaped body 1 serving as the portion 12 and the load receiving plate 2 embedded in the lower layer of the elastic band-shaped body 1 so as to straddle the play U and having both ends in the bridge axis direction leading to the shear deformation portions 12 respectively. In the expansion joint for a bridge provided so that the end of the elastic strip 1 is fixed to the bridge H by the anchor bolt AB, the center of the load receiving plate 2 is raised to form a substantially bow shape. The entire elastic band corresponding to the central portion of the load receiving plate 2 is set to be thin, and both ends of the load receiving plate 2 reaching the shear deforming portion 12 are made thin, so that the height of the shear deforming portion 12 is reduced. Is set large.
(Invention of claim 2)
The expansion joint for a bridge according to the present invention relates to the invention according to the above-mentioned claim 1, wherein the elastic band-shaped body 1 has a substantially constant thickness, and the elastic band-shaped body 1 maintains the substantially constant thickness while maintaining the load receiving plate 2 The center portion of the corresponding elastic band 1 is submerged from the other end portions, and when the bridge H is installed between the bridges H, the central portion of the elastic band 1 is deformed by the shear deformation portion 12. An internal reaction force is generated downward.
[0007]
The function of the expansion joint for bridges of the present invention will be described in the following embodiments of the present invention.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 shows an expansion joint J for a bridge according to an embodiment of the present invention in a state where no external force is applied. FIG. 2 shows the expansion joint J for a bridge installed between the bridges H, H. It shows the state where it was turned on. In FIG. 2, what is indicated by reference numeral U is a play space.
[Overall configuration of expansion joint J for bridges]
As shown in FIG. 1, this expansion joint J for a bridge includes an elastic band 1 and four grooves 10 formed on the upper surface of the elastic band 1 and extending in a direction perpendicular to the bridge axis direction of the bridge H. And two grooves 11 formed on the lower surface of the elastic strip 1 and extending in a direction perpendicular to the bridge axis direction of the bridge H, and a load receiving plate 2 buried in the lower center of the elastic strip 1. A load receiving plate 13 buried above the elastic band 1 and bolting plates 14 buried at both ends of the elastic band 1. The elastic band-shaped portion between them is a shear deformation portion 12.
[0010]
In this joint J, as shown in FIG. 1, the elastic band 1 corresponding to the load receiving plate 13 is sunk from the other end portions while maintaining the elastic band 1 at a substantially constant thickness. (In the figure, the sinking amount is indicated by a symbol FI).
[Installation of bridge expansion joint J on bridges H, H]
As shown in FIG. 2, the expansion joint J for bridge is installed via an anchor bolt AB in a recess h formed at an end of the bridge H, H, and in this installed state, the load receiving plate 13 sinks. The corresponding elastic band 1 is pushed up by the sinking amount FI, and the concrete surface CL of the bridges H, H and the entire upper surface of the bridge expansion joint J are so-called flush.
[0011]
Therefore, in the above-mentioned state in which the bridge expansion joint J is installed on the bridges H, H, in addition to the weight of the load receiving plate 13, the central portion of the elastic strip 1 corresponding to the load receiving plate 13 is subjected to shear deformation. Due to the deformation of the portion 12, a downward internal reaction force is generated in the central portion of the elastic band-shaped body 1.
[About elastic band 1]
The above-mentioned elastic strip 1 is a strip that is long in a direction perpendicular to the bridge direction, and is entirely made of rubber (for example, chloroprene rubber).
[About the load receiving plate 2, the load receiving plate 13, and the bolt fixing plate 15 ]
As shown in FIG. 2, the load receiving plate 2 is formed in a substantially arcuate shape with a raised central portion, and both ends reaching the shear deformation portion 12 are thinned. Therefore, as compared with the expansion joint for bridges described in the section of the prior art, the portion of the elastic strip 1 above the central region of the load receiving plate 2 is thinner, and the height of the shear deformation portion 12 is larger. Here, as described above, both ends of the load receiving plate 2 reaching the shear deformation portion 12 can be made thinner because this portion may be designed in consideration of only the shear load. The load receiving plate 2 can be made of cast steel, spheroidal graphite cast steel, hot pressed steel, or the like.
[0012]
The load receiving plate 13 and the bolting plate 14 are made of a steel plate.
[Functions of this bridge expansion joint J]
{Circle around (1)} In addition to the weight of the load receiving plate 2, the central portion of the elastic band 1 corresponding to the load receiving plate 2 is deformed by the shear deformation portion 12 so as to face the central portion of the elastic band 1 downward. Since the force is generated, even when the bridge H extends due to an increase in environmental temperature or the like and the distance between the bridges H, the distance between the bridges H decreases, the central portion of the elastic strip 1 becomes difficult to float from the floor of the bridge H. Therefore, it is possible to largely suppress the generation of the impact sound when the vehicle passes.
{Circle around (2)} Since the elastic band-shaped body 1 above the center area of the load receiving plate 2 is thin, sinking due to wheel load is small. Therefore, the vehicle traveling performance is improved and noise generation can be suppressed.
{Circle over (3)} Since the height of the shear deformation portion 12 is large, the shear deformation rate of the shear deformation portion 12 is small, and therefore, the following ability of the bridges H, H with respect to approaching / separating from each other is excellent.
(4) Unlike the ones described in the section of the prior art, the load receiving plate 2 is formed in a substantially bow shape with its central portion raised, and the both ends are thin, so that the weight is large. No.
[0013]
【The invention's effect】
Since the present invention has the above configuration, it has the following effects.
[0014]
From the contents described in the above-mentioned embodiment of the invention, (1) the weight is not increased, (2) the sinking due to the wheel load is small, and (3) the shear deformation rate of the shear deformation portion is small for bridge expansion joints. Could be provided.
[Brief description of the drawings]
FIG. 1 is a sectional view of an expansion joint for a bridge according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a state in which the bridge expansion joint is installed between opposing bridges.
FIG. 3 is a cross-sectional view of a preceding bridge expansion joint.
FIG. 4 is a cross-sectional view of a preceding bridge expansion joint.
[Explanation of symbols]
H Bridge U Play space AB Anchor bolt 1 Elastic band 2 Load receiving plate 10 Groove 11 Groove 12 Shear deformation part

Claims (2)

Grooves (10) and (11) extending at right angles to the bridge axis direction of the bridge (H) are formed on the upper and lower surfaces and shear between the adjacent upper surface side groove (10) and lower surface side groove (11). An elastic band (1) serving as a deformable portion (12), and both ends in the bridge axis direction are buried in a lower layer of the elastic band (1) so as to straddle a play (U), and both ends in the bridge axis direction are sheared portions (12). ), And a load receiving plate (2), and an elastic joint for a bridge which is installed such that the end of the elastic strip (1) is fixed to the bridge (H) by an anchor bolt (AB). The entire elastic band corresponding to the central portion of the load receiving plate (2) is set to be thin by raising the central portion of the load receiving plate (2) to form a substantially arcuate shape. The height of the shear deformation portion (12) is set large by making the both ends of the load receiving plate (2) reaching (12) thin. Bridges for the expansion joint to be. The elastic band (1) has a substantially constant thickness, and the central part of the elastic band (1) corresponding to the load receiving plate (2) is maintained while maintaining the substantially constant thickness of the elastic band (1). It is sunk from the other end portions, and when installed between the bridges (H) and (H), the shear deformation portion (12) deforms downward into the central portion of the elastic strip (1). The expansion joint for a bridge according to claim 1, wherein a reaction force is generated.

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