JPH0696842B2 - Bridge girder expansion and contraction absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to an expansion and contraction absorbing device for a bridge girder of a road bridge.

<Prior art> Bridge girder expands and contracts by several mm to several tens of mm depending on temperature changes. This amount increases as the span of the bridge girder increases and the temperature change amount increases. For this reason, expansion and contraction absorbing devices are used at the ends of road bridges or bridges of each bridge.

As conventional expansion and contraction absorbing devices, there are various structures such as a combination of steel fingers, a special structure of rubber, and a structure of expanding and contracting plates. However, in any structure, discontinuous unevenness remains on the road surface at the end of the bridge, which gives an impact to the vehicle running on it.

This shock not only makes the ride of the car worse,
It will be a source of vibration and noise, and will be a nuisance to the local residents. If it is even more severe, it will cause local damage to the bridge ends, in which case repair work will be difficult,
It has a great influence on it, such as traffic interruption and traffic regulation.

<Problems to be solved by the invention> To solve such a problem that discontinuous unevenness occurs on the running surface, connect the bridged end with an expansion device and add the same asphalt pavement on the surface layer to the road surface. It is possible to give it.
However, since the amount of expansion and contraction of the expansion / contraction device becomes excessive, the asphalt pavement surface is cracked in winter and swells in summer.

Therefore, the present invention distributes the expansion and contraction stress of the road surface pavement portion at the end of the bridge girder over a wide range of several meters in the road running direction, so that concentrated stress does not occur in each component and cracks and swelling occur on the pavement surface. To provide a stretchable absorber for bridge girder that does not occur.

<Means for Solving the Problems> In the expansion / contraction absorbing device for a bridge girder of the present invention, the end face of the bridge girder that opposes the convex portion that penetrates into the gap of the adjacent bridge girder and bulges downward. A steel stretchable plate integrally formed with a fixed portion to be fixed on top, an elastic filler filled in the convex portion, and an engraved upper part opened along the symmetry plane of the filler. The V-shaped cut, the filling material, the elastic sheet adhered to the fixing portion of the expansion plate and the floor surface of the bridge girder on both sides thereof, and having a length of several meters in the road surface direction, and the elastic sheet It is characterized in that it has a road surface pavement portion that is covered with an adhesive agent.

As the filler to be filled in the convex portion of the elastic plate of the present invention,
Synthetic rubber, especially asphalt-based urethane rubber is used.

The elastic sheet of the present invention has a large deformability when a shearing force is applied, and asphalt-based urethane rubber or synthetic rubber such as vulcanized rubber is preferable. The length of this elastic sheet in the running direction is approximately 400 of the amount of expansion and contraction of the bridge.
It is preferable to double or more, for example, in the case of a bridge with a stretch amount of 10 mm
It is about 4m. The thickness of the elastic sheet is preferably thicker as the amount of expansion and contraction increases, and is usually several mm to several tens mm. This may be configured by stacking a plurality of elastic sheets.

<Operation> When the distance between bridges changes due to expansion / contraction, the expansion / contraction plate also expands / contracts accordingly, and in particular, the convex portion elastically deforms, and the upper opening width of the V-shaped cut expands / contracts. In response to this primary expansion and contraction, the elastic sheet undergoes shear deformation to disperse and absorb each strain and stress of the road pavement over a wide range, resulting in local stress on the running surface of the road pavement. No cracking or bulging phenomenon occurs.

<Embodiment> FIG. 1 shows a sectional view in the traveling direction of an embodiment of the present invention.

A bridge girder 1 whose end face supported on a pier or abutment (not shown) expands and contracts in the traveling direction and a bridge girder or abutment upper floor slab 2 are constructed with a predetermined space a, for example, 10 cm, and bridged 1
The upper surface of the floor slab 2 and the like are flush with each other. The steel stretchable plate 3 includes a convex portion 4 having a substantially semicircular shape that is convex downward to enter a gap between bridge surfaces such as bridge girders facing each other, and one fixing portion 5 fixed on the bridge girder 1. The other fixing portion 6 fixed to another floor slab 2 or the like is integrally formed. An elastic filler 7 such as asphalt urethane rubber is filled inside the convex portion 4 of the elastic plate 3.
A V-shaped cut having an opening at the top is cut along the symmetry plane of the filling material 7. The elastic sheet 8 is adhered over a wide range having a length b in the traveling direction of about 4 m centering on the center of the elastic plate 3 and the filling in the convex portion 4. In the elastic sheet 8 in this embodiment, for example, unit sheets having a thickness of 5 mm and a size of 50 cm square are laid side by side, and the thickness of the central portion is maximized by sequentially increasing the number of laminated layers toward the central portion. A rubber asphalt-based synthetic resin is used as an adhesive between unit sheets and between bridges. An iron plate 9 is placed as a holding plate on the thickest part of the center of the elastic sheet 8. An asphalt road pavement is formed on these. This road pavement consists of a lower first layer 10 and an upper second layer 11
The wire mesh 12 is embedded between the first layer and the second layer in order to prevent fine cracks on the asphalt pavement surface. The first layer 10 and the elastic sheet 8 are joined by a rubber asphalt synthetic resin during asphalt pavement construction.

FIG. 2 shows another embodiment of the present invention. This embodiment is the first
What is different from the one shown in the figure is that the elastic sheet 8A is composed of one sheet in the traveling direction. The first
The same parts as those in the figure are designated by the same reference numerals.

<Effects of the Invention> According to the present invention, the elastic plate 3 having a convex portion in the center, the filling material 7 with the V-shaped cut filling the convex portion and opening upward, the elastic sheet 8, the asphalt road surface. The pavement parts 10 and 11 and the laminated structure of the adhesive layer that bonds or joins these together forms the stretchable part of the bridge, and the road surface is continuous on the bridge and on the slab, and there are no irregularities between them. So
The stress due to the expansion and contraction of the bridge is dispersed and absorbed in each part of the laminated structure, there are no places where concentrated stress occurs, and neither cracks nor bulges occur on the road surface. In particular, since a V-shaped cut is engraved on the upper surface of the filling material 7, according to an experiment, the distance a of the bridge girder a
Despite the expansion and contraction, the vertical fluctuation of the upper surface of the filler 7 was hardly recognized. On the other hand, as a comparative example, an experiment was conducted on a device without a V-shaped cut,
The vertical fluctuation of the upper surface of the filler 7 was recognized. In addition, both the lower and upper surfaces of the elastic sheets 8 and 8A are bridged 1,
Since it is adhered and joined to the upper surface of 2 and the lower layer 10 of the road pavement portion, no lateral slippage occurs at the interface, and therefore the concentrated load due to expansion and contraction does not act on the road surface pavement portions 10 and 11, and The road surface pavement will not be internally destroyed by the load.

[Brief description of drawings]

 FIG. 1 is a sectional view in the traveling direction of an embodiment of the present invention. 1,2 ...... Bridge girder or abutment floor slab 3 ...... Expansion plate 4 ... Convex part of expansion plate 5, 6 ...... Expansion plate fixed part 7 ...... Filler 8 ...... Elastic sheet 10 ...... Road surface pavement part Lower layer 11 …… Upper layer of road pavement 12 …… Kinzou

Claims (3)

[Claims] 1. A steel body integrally formed with a convex portion whose end faces are opposed to each other and enter a gap between adjacent bridge girders and bulge downward and a fixing portion fixed onto the opposed bridge girders. An elastic plate, and an elastic filler filled in the convex portion,
V that is engraved along the symmetry plane of the filling material and opens at the top
An elastic sheet having a character-shaped cut and a length of several meters in the direction of the line, the central portion that is above the elastic plate is thickest, and the thickness is gradually reduced toward both ends, and road surface pavement that covers the elastic sheet. And a bridge girder expansion and contraction absorbing device having an adhesive layer for bonding the upper and lower surfaces of the elastic seed to the bridge and the road pavement. 2. The elastic sheet according to claim 1, wherein the elastic sheet is composed of unit sheets, and the number of laminated sheets is sequentially increased toward the central portion, and the unit sheets are adhered to each other with an adhesive. Expansion and absorption device for bridge girder. 3. An expansion and contraction absorbing device for a bridge girder according to claim 1 or 2, wherein a pressing plate made of a substantially rigid body is provided on a central portion of said elastic sheet having the largest thickness.