JP2001303516A - Shift restriction device for bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift restriction device preventing the excessive uplifting displacement and horizontal displacement of an upper structural body of a bridge and capable of being simply constructed at a low cost. SOLUTION: The lower section of a cable 22 made of flexible and high- strength stranded wires is buried and integrally fixed in a concrete lower structural body of the bridge, and the upper section is fixed to the upper structural body 12. The lower structural body 10 and the upper structural body 12 are vertically connected via the cable 22 to prevent the excessive uplifting displacement and horizontal displacement of the upper structural body 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movement restricting device for preventing an upper structure in a bridge from being lifted and displaced in a horizontal direction more than an allowable amount with respect to a lower structure.

[0002]

2. Description of the Related Art Conventionally, a rubber bearing is interposed between a lower structure and an upper structure in a bridge, and the upper structure is elastically supported by the rubber bearing. Is being done. FIG. 4 shows a state in which the upper structure is elastically supported by a rubber bearing interposed between the upper structure and the lower structure in the bridge.

[0003] In the figure, 200A and 200B are piers, respectively.
Reference numeral 204 denotes an abutment, and reference numeral 204 denotes a bridge girder. Reference numeral 206 denotes a rubber bearing interposed between a lower structure including the piers 200A and the abutment 200B and an upper structure including the bridge girder 204.

Conventionally, as such a rubber bearing, a lower end and an upper end are attached and fixed to a lower structure and an upper structure, respectively, and a so-called B in which the lower structure and the upper structure are connected via a rubber bearing. A rubber bearing called a type, and is simply sandwiched between the lower structure and the upper structure,
Pad-type rubber bearings (the rubber bearings belong to the A type) which do not connect the lower structure and the upper structure are used, respectively.

For example, in a bridge, the upper structure expands and contracts due to various factors such as loading of a load, temperature change, creep of concrete, and prestressing force, and also contracts after the upper structure is erected. In the case of the former B type rubber bearing, the upper structure and the lower structure are moved integrally with the upper structure and the lower structure, respectively, in addition to supporting the vertical load of the upper structure, and the upper structure is deformed by shear elastic deformation of the rubber. Absorbs the horizontal relative displacement between the upper structure and the lower structure, and keeps the upper structure and the lower structure in a connected state even when an upward lift acts on the upper structure, so that the upper structure It has the function of preventing relative displacement upwards beyond a certain level, and is mainly used for important bridges such as large bridges and long bridges.

On the other hand, the latter pad-type rubber bearing is the former B-type rubber bearing.
In addition to supporting the vertical load of the upper structure as well as the rubber bearing of the type, when the horizontal displacement between the upper structure and the lower structure is relatively small, it itself shears elastically deforms within a certain range. Absorbs horizontal displacement between the structure and the substructure.

[0007] The upper structure bends due to the loading of the load, thereby causing a rotational movement about the support portion of the rubber bearing. Both the former B-type rubber bearing and the latter pad-type rubber bearing have a function of absorbing the rotational movement of the rubber by deformation of the rubber.

Incidentally, the former type B rubber bearing, that is, a rubber bearing in which the upper structure and the lower structure are connected vertically and horizontally, is inevitably complicated in structure and large in size. There was a problem that the weight was heavy and the price was high.

FIG. 5 shows an example of the former type B rubber bearing. In the drawing, reference numeral 208 denotes an upper structure including a bridge girder and the like, 210 denotes a lower structure including an abutment, a pier, and the like, and 206A denotes a B type rubber bearing.

[0010] The lower end of the rubber bearing 206A is fixedly connected to the lower structure 210 via a lower shoe 214 and a base plate 216, both of which are made of steel, and the upper shoe 218 and the sole plate 220, both of which are made of steel at the upper end. And is fixedly connected to the upper structure 208 via the.

An anchor bar 221 for fixing extends from the base plate 216, and the anchor bar 221 is embedded in the lower structure 210.
Although not shown, a fixing anchor bar extends upward from the sole plate 220, and the upwardly extending anchor bar is embedded in the upper structure 208.

In FIG. 1, reference numeral 222 denotes a shear key.
Lower shoe 214, upper shoe 218 and corresponding base plate 2
16, and between the sole plates 220. The shearing keys 222 receive a large force in the shearing direction. Reference numeral 224 denotes a shearing key, which is disposed over the lower end and the upper end of the rubber bearing 206A and between the corresponding lower and upper shoes 214 and 218.

In the case of the B type rubber bearing 206A,
When a horizontal relative displacement occurs between the upper structure 208 and the lower structure 210, the structure itself is sheared and elastically deformed in the same direction, and the horizontal relative displacement between the upper structure 208 and the lower structure 210 is increased. It not only absorbs the displacement, but also suppresses a certain or more horizontal displacement between the upper structure 208 and the lower structure 210 by its own elastic deformation resistance. Also, when an upward lift acts on the upper structure 208, the upper structure 208 acts to suppress a relative upward displacement (floating displacement) of the upper structure 208 by its own elastic deformation resistance.

For this function, the rubber bearing 206A of this type can be formed by increasing the thickness of the upper and lower reinforcing plates inside the rubber bearing 206A, or by interposing the sole plate 220 and the base plate 216 via the upper and lower shoes 218 and 214. To the base plate 216, the fixing bar is extended from the sole plate 220, and the shearing keys 222 and 224 and the fitting recesses for them are provided. Furthermore, rubber bearing 20
It is necessary to increase the amount of deformation of the 6A main body, and as a result, the rubber bearing 206A is inevitably complicated in structure and large in size, thereby making the price of the 206A extremely high.

On the other hand, in the case of the pad type rubber bearing,
It is merely set in a state of being sandwiched between the upper structure and the lower structure, and the upper structure and the lower structure are not connected via rubber bearings. It is simple and light in weight and can therefore be constructed inexpensively.

However, in the case of the pad-type rubber bearing, since the lower structure and the upper structure are not connected to each other, the floating cannot be prevented when an upper lift is applied to the upper structure. Is included. In particular, when the degree of floating is severe, unless a special bridge-fall preventing device capable of suppressing the upward lift is provided, a risk of falling is caused.

Further, in the case of the pad-type rubber bearing, the rubber bearing itself has a movement limiting function when the horizontal displacement becomes larger than a certain value, which is not shown, but is seen in the B-type rubber bearing. It is difficult.

[0018]

SUMMARY OF THE INVENTION The device for limiting movement of a bridge according to the present invention has been devised to solve such a problem. According to a first aspect of the present invention, there is provided a movement restricting device provided separately from a bearing for elastically supporting an upper structure of a bridge, wherein a lower portion of a flexible and high-strength stranded wire is made of concrete made of the bridge. While being embedded and fixedly integrated in the lower structure, the upper part is fixed to the upper structure, and the lower structure and the upper structure are vertically connected via the stranded wire. The present invention is characterized in that the lower structure is prevented from being lifted and horizontally displaced more than an allowable amount.

According to a second aspect of the present invention, in the first aspect, the movement restricting device is combined with a pad-type rubber bearing interposed between the upper structure and the lower structure in a sandwiched state and in a non-coupled state. And a displacement absorption device that elastically supports the upper structure while restricting the upper structure from moving relative to each other.

According to a third aspect of the present invention, in the second aspect, the upper structure and the lower structure are moved up and down with the stranded wire bending a portion between the upper structure and the lower structure. And the amount of flexing thereof is set to an amount such that the pad-type rubber bearing can be effectively elastically deformed and the stranded wire is in a tensioned state at least after exceeding the effective elastic range. I do.

According to a fourth aspect of the present invention, in the third aspect, a mortar-shaped concave portion is formed in a lower surface portion of the upper structure and an upper surface portion of the lower structure, and the stranded wire is formed in the concave portion. It is characterized in that an elastic member which keeps its shape in a bent state and elastically deforms itself when tensioned is filled so as to surround the stranded wire.

[0022]

As described above, the present invention embeds the lower part of a flexible and high-strength stranded wire inside a concrete lower structure of a bridge to fix and integrate it.
The upper part is fixed to the upper structure and they are connected up and down.According to this movement restriction device, even when an upper lift acts on the upper structure, the upper structure exceeds the allowable amount. Excessive floating can be prevented. Further, according to the movement restriction device, it is possible to prevent the upper structure from being excessively displaced in the horizontal direction with respect to the lower structure.

This movement restricting device prevents the upper structure from floating due to the tension of the flexible and high-strength stranded wire, and has a sufficient resistance and blocking against the floating of the upper structure. Have power. Therefore, the function of the conventionally installed bridge prevention device can be performed by the movement restriction device. That is, the use of the movement restriction device of the present invention makes it possible to omit the conventional bridge prevention device.

The flexible high-strength stranded wire can be a steel wire stranded wire. The upper part of the stranded wire can be fixed to the upper structure in a dry manner with bolts, nuts, or the like, or can be wet-fixed by embedding in the upper structure in some cases.

Heretofore, as a bridge fall prevention device, a device in which a long steel anchor bar is deeply embedded in a concrete lower structure has been used. The reason for using such a long anchor bar and burying it deeply in the lower structure is to secure a sufficient adhesive force between the anchor bar and the lower structure. If a long steel bar is used and deeply buried in the inside of the lower structure, its handling becomes difficult and the cost becomes high. Further, there is a case where the vertical dimension of the embedded portion of the steel anchor bar in the lower structure cannot be sufficiently secured.

On the other hand, in the movement restricting device of the present invention, since a flexible stranded wire is used as a connecting member between the lower structure and the upper structure, the lower portion is embedded in the lower structure. In bonding and integrating, a sufficient adhesive force can be secured without deeply embedding the steel anchor bar as in the case of embedding the steel anchor bar. This is because, in the case of a flexible stranded wire, a large contact area and a close contact area with the lower structure can be ensured, so that a sufficient necessary adhesive force can be ensured even if the wire is not deeply embedded.

Therefore, according to the present invention, the embedded structure in the lower structure can be fixedly integrated with the lower structure without substantially being restricted by the vertical dimension of the embedded portion, and can be firmly joined and integrated with each other. In addition, the device is lightweight and has good workability, and the cost required for the device can be reduced.

The movement restricting device of the present invention has a function of suppressing the floating of the upper structure of the rubber bearing of the B type described above. Therefore, if the movement restricting device of the present invention is used, the rubber bearing is provided. There is no need to use an expensive B-type rubber bearing, and a simple and inexpensive pad-type rubber bearing is sufficient.

That is, when the movement restricting device of the present invention is used, the function of the B type rubber bearing can be achieved by combining with the pad type rubber bearing, and the cost as a whole is lower than that of the B type rubber bearing. And the cost can be reduced (claim 2).

In this case, the portion of the stranded wire between the upper structure and the lower structure is bent, and the amount of bending is adjusted so that the pad type rubber bearing can effectively elastically deform and at least exceed the effective elastic range. After that, it can be set to such an amount that the bent portion becomes in a tensioned state (claim 3). In this way, the function of the pad-type rubber bearing is not impaired by the connection between the lower structure and the upper structure by the stranded wire, that is, by providing the movement restricting device, and in an area where the relative displacement is small, The pad-type rubber bearing can work well, and the movement limiting device can perform functions that cannot be achieved with the pad-type rubber bearing.

When the portion of the stranded wire between the upper structure and the lower structure is bent as described above, when it is necessary to replace the rubber bearing, the upper structure is easily lifted up. The rubber bearing in the installed state can be removed and a new rubber bearing can be installed. That is, the replacement of the rubber bearing can be easily performed, and the cost at that time can be reduced.

In the present invention, a mortar-shaped recess is formed on the lower surface of the upper structure and the upper surface of the lower structure, and the recess is filled with an elastic member so as to surround the stranded wire. The twisted wire can be kept in the above-mentioned bent state while being elastically deformed at the time of its tension (claim 4).

In this way, the stranded wire is directly or locally strongly hit or rubbed against the embedment hole or the insertion hole of the stranded wire of the stranded wire in the lower structure or the upper structure, thereby forming the stranded wire. In addition, it is possible to prevent the upper and lower structures from being partially damaged, and to obtain an effective flexible deformation length between the upper structure and the lower structure in the stranded wire.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 10 denotes a concrete lower structure including a bridge pier, an abutment, etc., 12 denotes a concrete upper structure including a bridge girder, and 14 denotes a pad-type rubber bearing interposed therebetween. Reference numeral 16 denotes a pad-type rubber bearing which connects the lower structure 10 and the upper structure 12 to prevent the upper structure 12 from being lifted excessively beyond a certain level and displaced in the horizontal direction. 14 together with a displacement absorbing device.

FIG. 2 is an enlarged view of the interposed portion of the pad-type rubber bearing 14 and its periphery. As shown in FIG. 2, the pad-type rubber bearing 14 has a plurality of rubber layers 18 and internal reinforcement. Plates (steel plates) 20 are alternately stacked up and down, and they are integrally vulcanized and bonded.

The pad-type rubber bearing 14 has a lower surface and an upper surface which are not connected to the lower structure 10 and the upper structure 12 (in a state of being cut off), respectively, and the lower structure 10 and the upper structure It is installed in a state sandwiched between the twelve.

FIG. 3 shows a specific configuration of the movement restricting device 16. In the figure, reference numeral 22 denotes a PC steel cable (strand) which is a main component of the movement restricting device 16, the lower portion of which is embedded in the concrete lower structure 10 over a certain length, and the lower structure is formed in the same portion. It is integrated with the body 10. In FIG. 3 (A), D is the embedded portion 22A.
Represents the top and bottom dimensions.

On the other hand, a bolt 24 is provided at the upper end of the cable 22.
Are fixed to the upper structure 12 through bolts 24, nuts 28 screwed into the bolts 24, and plates 30 after passing through the insertion holes 26 of the upper structure 12. Here, the upper part of the cable 22 is
Although it is dry-fixed with a nut 28 or the like, it is also possible to embed the upper part inside the concrete upper structure 12 and fix and integrate it in some cases.

The lower surface of the upper structure 12 and the lower structure 10
Are formed on the upper surface of the elastic member 34. The concave portions 32 are formed of elastic members 34 made of rubber or the like.
It is buried in. Here, the elastic member 34 is the cable 2
2 so as to be elastically deformed when tensed.

In the present embodiment, the cable 22 is bent at a portion between the upper structure 12 and the lower structure 10, more precisely, at a portion between the upper end and the lower end of each concave portion 32. The elastic member 34 holds the portion of the cable 22 between the upper end and the lower end of each recess 32 in a bent state. As shown in FIG. 3B, the portion of the cable 22 excluding the embedded portion 22A is covered with a covering material 36 such as rubber.

In the case of the movement restricting device 16 of the present embodiment, the portion between the upper structure 12 and the lower structure 10, more precisely, the portion between the upper end and the lower end of each recess 32 is the effective flexible portion 2.
2B, and the entire effective flexible portion 22B is bent in advance by a predetermined amount in the installation state of the upper structure 12. The amount of deflection is set to such an amount that the pad-type rubber bearing 14 can be effectively elastically deformed and the effective flexible portion 22B becomes in a tensioned state at least after exceeding the effective elastic range.

More specifically, the pad-type rubber bearing 14 is elastically deformed up and down vertically when the upper structure 12 is installed. Therefore, when an upward lift acts on the upper structure 12, the pad-type rubber bearing 14 is somewhat deformed. Is able to follow a slight vertical displacement of the upper structure 12 by restoring the shape in the vertical direction. Furthermore, the horizontal displacement of the upper structure 12 can be followed by the horizontal shear elastic deformation. In this example, the effective flexible portion 22 is previously set so that the elastic deformation of the pad-type rubber bearing 14 is not hindered.
The amount of deflection of B is determined.

When the upward relative displacement and the relative displacement in the left-right direction of the upper structure 12 are about to become larger than the permissible amount, the effective flexible portion 22B is in a tensioned state at that point, and further. Acts to prevent the upper structure 12 from being displaced.

As described above, according to the movement restricting device 16 of this embodiment, the excessive lifting displacement and the horizontal displacement of the upper structure 12 can be prevented, and there is a sufficient resistance and stopping force against the displacement. are doing. Therefore, it is possible to omit the conventional fall prevention device.

In addition, in this embodiment, a flexible and high-strength cable 2 is used as a connecting member between the lower structure 10 and the upper structure 12.
2, a large contact area and close contact area with the lower structure 10 can be ensured.
Sufficient adhesive strength can be ensured even if it is not deeply embedded in the substrate.

Therefore, according to the present embodiment, the lower structure 10 can be fixedly integrated with the lower structure 10 without substantially being restricted by the vertical dimension of the embedded portion in the lower structure 10, and the apparatus is lightweight and workability is improved. And the cost required for the apparatus can be reduced.

Further, according to the present embodiment, the pad-type rubber bearing 14 can be sufficiently operated in a region where the relative displacement is small, and the movement restricting device 16 can exhibit functions that cannot be achieved by the pad-type rubber bearing 14.

Further, when it becomes necessary to replace the pad-type rubber bearing 14, the pad-type rubber bearing 14 can be easily replaced by lifting the upper structure 12, and the cost at that time can be reduced. it can.

Further, in this embodiment, since the concave portion 32 is formed in the lower surface of the upper structure 12 and the upper surface of the lower structure 10 and the concave 32 is filled with the elastic member 34, the lower structure 10, When the edge of the hole in the burial hole or insertion hole of the cable 22 in the upper structure 12 and the cable 22 locally strongly hit or rub against each other, the cable 2
2 to the lower structure 10 and the upper structure 12 can be prevented from being partially damaged, and an effective flexible deformation length (effective flexible portion) between the upper structure 12 and the lower structure 10 in the cable 22 can be prevented. 22B) can be secured long.

Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be configured in variously modified forms without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing a movement restricting device according to an embodiment of the present invention together with a peripheral portion thereof.

FIG. 2 is an enlarged view showing a pad-type rubber bearing and its peripheral portion in FIG. 1;

FIG. 3 is an enlarged view showing the movement restriction device and its peripheral portion in FIG. 1;

FIG. 4 is a view showing a conventional support device using a rubber bearing in a bridge.

FIG. 5 is a diagram showing an example of a conventional rubber bearing in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lower structure 12 Upper structure 14 Pad-type rubber bearing 16 Movement restriction device 22 Cable (stranded wire) 22A Embedding part 22B Effective flexible part 32 Depression 34 Elastic member

Claims (4)

[Claims] 1. A movement restricting device provided separately from a bearing for elastically supporting an upper structure of a bridge, wherein a lower portion of a flexible and high-strength stranded wire is provided inside a concrete lower structure of the bridge. The upper structure is fixed to the upper structure, and the lower structure and the upper structure are vertically connected to each other through the stranded wire, and the upper structure is attached to the lower structure. A movement restricting device for a bridge, wherein floating displacement and horizontal displacement are prevented from exceeding an allowable amount. 2. The movement limiting device according to claim 1, wherein the movement limiting device is used in combination with a pad-type rubber bearing interposed between the upper structure and the lower structure in a non-connected state. And a displacement absorbing device that elastically supports the upper structure while restricting the upper structure from moving relative to each other. 3. The upper structure and the lower structure according to claim 2, wherein the stranded wire flexes a portion between the upper structure and the lower structure, and connects the upper structure and the lower structure vertically. And the amount of deflection thereof is set to such an amount that the pad-type rubber bearing can be effectively elastically deformed and the stranded wire is in a tensioned state at least after exceeding the effective elastic range. apparatus. 4. The mortar according to claim 3, wherein a mortar-shaped recess is formed in a lower surface of the upper structure and an upper surface of the lower structure, and the stranded wire is held in a bent state in the recess. A movement restricting device for a bridge, characterized in that an elastic member, which elastically deforms itself when tensioned, is filled in a state surrounding the stranded wire.