JPH0235852Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a bridge fall prevention device used in structures such as bridges, especially a bridge fall prevention device suitable for use at the fixed end of a bridge girder, and more specifically a bridge fall prevention device that is effective for uneven subsidence of the ground. This invention relates to a prevention device.

Here, the fixed end of a bridge girder is a pier with a support configured to support the bridge girder and release displacement such as deflection of the bridge girder, but restrain displacement such as expansion and contraction, so-called the origin of expansion and contraction of the bridge girder. For example, if the type of bridge is a simple girder, one of the piers is a fixed end, the other piers support the girder, and are configured to release displacement such as deflection and expansion/contraction of the bridge girder. If the girder is a continuous girder, one pier is generally provided with a fixed end, and the other piers are used as movable ends.

In addition, bridge fall prevention devices are installed when the supports that support the bridge girder on the bridge piers do not have a function to prevent the bridge girder from falling, or when the distance between the bridge girder and the pier is narrow and it is difficult to install it, and generally rubber is used as the support. Rubber bearings with multiple layers of elastic body and reinforcing plate, wire bearings without fall prevention function, base plate bearings,
This is applied when using sealed rubber bearings, etc.

BACKGROUND OF THE INVENTION Conventionally, bridge fall prevention devices used at fixed ends of structures such as bridges often have structures as shown in FIGS. 1 to 4.

That is, the bridge collapse prevention device L includes a casing 2 having a circular cross-sectional shape and an opening 1 at one end, and one end of which is fitted into the casing 2 so as to form a gap 33 that can allow the deflection of the bridge girder G. Rod-shaped body 4
The casing 2 is embedded and fixed in the bridge girder G so that the opening 1 is flush with the lower surface of the bridge girder G, one end of the rod-shaped body 4 is inserted into the casing 2, and the other end is inserted into the bridge pier B. It is installed by burying and fixing it in the ground.

The excessive horizontal force acting on the bridge girder G is restrained by the contact between the casing 2 and the rod-shaped body 4, thereby preventing the bridge girder G from falling.

Note that the vertical and horizontal loads that normally act on the bridge girder G are supported by the supports S, and the bridge collapse prevention device L does not support these loads.

In addition, displacements such as deflection of the bridge girder G are also released by the bearings S, and even when these displacements are released, the bridge fall prevention device L allows this movement in the gap 3 between the casing 2 and the rod-shaped body 4, so there is no need to do anything. There will be no problem.

However, such bridge collapse prevention device L also
There are problems that make it difficult to apply this method to bridges whose location conditions have become harsher in recent years.

Specifically, due to problems such as securing construction sites and pollution, roads and railways are increasingly being constructed on poor ground such as reclaimed land, river areas, and wetlands, avoiding urban areas.

As a result, it is inevitable that bridges will undergo some uneven settlement over time, and when such a situation occurs, prevent damage to the bridge girder G and vehicles traveling on the bridge girder G. pier B
A method has been adopted in which the bridge girder G is restored to its normal state by raising the height of the bridge girder G.

This will be explained in FIGS. 5 and 6. In other words, as shown in Figure 5, when the pier B lowers due to uneven ground subsidence, the bridge girder G also lowers its position from its normal position H to H' according to the amount of subsidence (as shown by the broken line in the figure). Its function as a bridge will be impaired.

Therefore, if such a situation occurs, as shown in Figure 6, the bridge girder G will be raised to the normal position H and the pier B will be raised, in other words, the pier B will be raised by the amount of settlement X (X = HH'). By doing so, work is being done to restore normal conditions.

However, although these operations restore the bridge's function, raising the height of the piers B causes a new problem in the bridge collapse prevention device L.

That is, by raising the height of the bridge pier B, the bridge collapse prevention device L reduces the length of the rod-shaped body 4 located inside the casing 2, in other words, the pressure receiving (contact) area decreases.

In addition, the contact position between the casing 2 and the rod-shaped body 4, in other words, the point of application of the load is before sinking (arrow K in the figure).
This changes after the elevation is raised (arrow K' in the figure), and the action of excessive horizontal force such as during an earthquake causes deformation of the rod-shaped body 4, and even damage and falling of the bridge girder G, resulting in uneven settlement. There is a problem that it is difficult to apply this method to bridges where it is predicted that

The present invention was developed to solve these problems, and even after the bridge is elevated due to subsidence, the pressure receiving area of the casing and rod-shaped body against horizontal force makes the point of load application the same as before subsidence. The technical challenge is to obtain a bridge collapse prevention device that can prevent bridges from falling.

In order to solve the above problems, the present invention adopts the following technical means (configurations).

That is, in a bridge fall prevention device used at a fixed end of a bridge girder, which consists of a casing that is buried and fixed in the bridge girder, and a rod-shaped body that has one end fitted into the casing and the other end that is buried and fixed in the bridge pier, the casing has one end The casing has an opening in the casing and is formed into a box shape with a rectangular cross-sectional shape, and a holding plate is disposed at the end of the opening to hold the pressure-bearing material arranged in the casing at a predetermined position, Further, the rod-shaped body is formed into a columnar shape with a rectangular cross-sectional shape.

The bearing pressure material and the rod-shaped body are disposed in the casing so as to face each other to the bridge axis and the inner wall in the direction perpendicular to the bridge axis, and the rod-shaped body is fitted with its end beyond the bearing pressure material. It adopts a structure in which it is inserted.

By adopting the above-mentioned means, the present invention has the following effects.

By interposing a bearing material between the rod-shaped body and the casing, and by inserting the rod-shaped body into the casing beyond the bearing pressure material, the load application point and pressure-receiving area can be kept subsidence even after the pier has been raised due to subsidence. The distance between the rod-shaped pier and the bridge girder, in other words, the distance from the load application point, can be made the same as before by embedding the amount of settlement during elevating the rod-shaped body. This can prevent bending deformation and damage to bridge girders.

Further, since the pressure-bearing material is supported by a retaining plate disposed at the opening end of the casing, it is possible to prevent the pressure-bearing material from falling off.

Furthermore, since the normal displacement that occurs in the bridge girder is followed by the deformation of the bearing pressure material, it has great effects such as not impeding the function of the bearing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

10 is a bridge collapse prevention device M buried and fixed in the bridge girder G
The casing 10 is formed into a box shape with an opening 11 at one end and a rectangular cross section.

12 is a rod-shaped body whose one end is fitted into the casing 10 so as to form a predetermined gap with the inner wall thereof, and whose other end is embedded and fixed in the pier B;
is formed into a columnar shape with a rectangular cross section. Reference numeral 13 denotes a retaining plate disposed at the end of the opening 11 of the casing, and the retaining plate 13 is disposed so that the rod-shaped body 12 does not come into contact with it when allowing the bridge girder G to deflect.

14 is a pressure-bearing material arranged inside the casing 10;
The bearing pressure member 14 is composed of a laminate of a rubber elastic body 15 and a reinforcing plate 16, and the casing 10 and the rod-shaped body 1
It is supported by the holding plate 13 and disposed in the gap between the two in the bridge axis and in the direction perpendicular to the bridge axis.

17 is a sealing material disposed between the pressure-bearing material 14 and the holding plate 13.

The bridge collapse prevention device M of the present invention has one end of a rod-shaped body 12 placed in a casing 10 in which bearing pressure members 14 are arranged to face each other in the direction perpendicular to the bridge axis and the bridge axis. In other words, a length commensurate with the amount of subsidence is made to protrude from the bearing pressure member 14 and is inserted.

Next, a holding plate 1 is attached to the end of the opening 11 of the casing.
3 and supporting the pressure bearing material 14, it is assembled.

Then, the casing 10 is buried and fixed in the bridge girder G so that the end of the opening 11 thereof is substantially flush with the lower surface of the bridge girder G, and the rod-shaped body 12 protruding from the casing 10 is buried and fixed in the bridge pier B. Then,
This is something that must be installed on a bridge.

With this configuration, even if the pier B sinks unevenly and the pier B is raised, the load application point and pressure receiving area for the horizontal force of the rod-shaped body 12, casing 10, and bearing material 14 will not change. Therefore, the same function as when installed is emitted.

Further, the displacement of the bridge girder G, that is, the slight deflection in the bridge axis direction and in the direction perpendicular to the bridge axis, is allowed by the pressure deformation of the bearing members 14, respectively.

In this embodiment, the bearing pressure member 14 is constructed from a laminate of a rubber elastic body 15 and a reinforcing plate 16, but is not limited to this, and a spring elastic body such as a leaf spring may also be used. In cases where deflection in the right angle direction can be ignored, a plate-shaped body made of synthetic resin, metal, or the like may be used as the bearing member 14 disposed in that direction.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the installation state of a conventional bridge fall prevention device, Fig. 2 is a longitudinal front view showing the conventional bridge fall prevention device, Fig. 3 is a longitudinal sectional side view thereof, and Fig. 4 is a longitudinal sectional view showing the conventional bridge fall prevention device. 2, FIGS. 5 and 6 are explanatory diagrams of the submerged state and raised state of the bridge pier, FIG. 7 is a longitudinal sectional front view showing the bridge collapse prevention device of the present invention, and FIG. 8 is a vertical side view thereof, FIG. 9 is a sectional view taken along line C-C in FIG. 7, FIG. 10 is a sectional view taken along line D-D in FIG. 7, and FIG. 11 is a section E section in FIG. The enlarged view, FIG. 12, is an enlarged view of section F in FIG. 10...Casing, 11...Opening, 12...
... Rod-shaped body, 13 ... Holding plate, 14 ... Bearing material.

Claims (1)

[Scope of utility model registration request] In a bridge fall prevention device used at a fixed end of a bridge girder, which is composed of a casing buried and fixed in a bridge girder, and a rod-shaped body having one end fitted into the casing and the other end buried and fixed in a bridge pier, the casing has an opening at one end. It is formed into a box shape with a rectangular cross section, and a holding plate is arranged at the opening end of the casing to hold the pressure-bearing material arranged inside the casing in a predetermined position. is formed into a columnar shape with a rectangular cross-sectional shape, and the bearing pressure material and the rod-like body are arranged in the casing so that the bearing pressure material faces the bridge axis and the inner wall in the direction perpendicular to the bridge axis, respectively, A bridge collapse prevention device used at a fixed end of a bridge girder, characterized in that the end of the rod-shaped body is inserted beyond the bearing material.