JP3122612B2 - Falling bridge prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a bridge from falling from a pier of the bridge when an external force such as an earthquake is applied to the bridge.

[0002]

2. Description of the Related Art Conventionally, bridges made of iron, reinforced concrete, or prestressed concrete adjacent to a pier are mounted and connected. For example, bridges for rivers and highways are mainly used as measures against earthquakes. As shown in FIG. 19, a steel plate fall prevention device 4 is fixed between the side walls of the adjacent bridge girders 2 and 3 on the pier 1 with bolts and nuts.

[0003] The fall prevention device 4 prevents the bridge girder from falling off the pier due to shaking in the longitudinal direction of the bridge girder during an earthquake.

[0004]

However, depending on the magnitude of the seismic force, the fall prevention device 4 is broken,
A bridge girder may fall from the pier 1 and cause fatal damage to people, cars, objects, etc. on the ground. Therefore, recently, as shown in FIGS.
Bridge prevention device 5 with a cable bundled with C steel strands
Is attached.

As shown in FIG. 21, the structure of the bridge prevention device 5 is such that the fixing members 6, 7 are rotatably mounted on the side wall surfaces of the bridge girders 2, 3 at appropriate intervals by bolts 6a, 7a. Have been.

A cable 1 is provided between brackets 8 and 9 erected perpendicularly to the side walls of the bridge girders of the fixing devices 6 and 7.
0 is provided, and cushioning materials 11 are interposed at both ends thereof, and are fixed by fixing nuts 12.

At the end of the cable 10, as shown in FIG. 22, a sleeve (hereinafter referred to as an apartment) having a thread groove formed on the outer periphery is fixed to a metal apartment 13 made of, for example, steel. The connection portion is covered with a socket cover 14.

As shown in FIG. 23, even if one of the bridge girders 2 and 3 is displaced from the pier 1 and one of the bridge girders falls as shown in FIG. To protect the bridge girder from reaching the ground.

In this way, the damage caused by the drop of the bridge girder is prevented. However, the above-mentioned bridge fall prevention device 5 has the following problems. That is, not only the case of falling due to the displacement along the longitudinal direction of the bridge girder but also the vibration in the direction perpendicular to the longitudinal direction of the bridge girder becomes complicated due to the shaking at the time of the earthquake, and the fixing devices 6 and 7 rotate. Even if it is movable, it hardly rotates freely in practice, and bending and shearing forces are generated in the fixing tools 6, 7 and the cable 10, which is inconvenient.

For example, when the temperature becomes higher and the temperature rises and the bridge girders 2 and 3 are extended and the gaps between them are reduced as compared with the air temperature when the bridge girder fall prevention device 5 is set, at the same time, the fixing device The brackets 8 and 9 of 6, 7 also approach each other, and the cable 10 loses tension and loosens. Therefore, the cable 10 was not preferable because of looseness.

As described above, the conventional bridge prevention device has problems to be solved in local bending failure and shearing failure of the fixing device and the cable.

[0012]

The gist of the present invention for solving the above-mentioned problems of the bridge fall prevention device according to the present invention is that at least one of the structures is a movable structure, and each pair of opposing structures is provided .
A fixing unit having a fastening member for the cable provided in Kotan side, and the cable was installed between the both said fixing means, said cable
Cable with a through hole and near the fixing end of the cable.
And a deflecting device provided on the
Only in emergencies without being affected by the installed cables.
Cable in an emergency situation
Deflectors that are affected by
On the attachment end side, the cable is
Constructed in a shape that is maintained in an orthogonal direction, facing
On the object side, songs that are suddenly added to the cable
Cables to prevent localized stresses and shear forces
Formed on a curved surface with a radius of curvature greater than the minimum bending radius of
That is.

[0013] Also, the installed cable has an emergency
Cable expands and contracts in response to sudden shocks
Relief means are provided on the fixing end side;
The relaxing means for expanding and contracting the cable includes a fastening member and a cable.
Elastic means provided between the fixing end of the cable and the fixing end;
Further, the elastic means has a conical hole for securing a large amount of expansion and contraction.
Attached to an il spring and a support plate for the conical coil spring.
And said plate-shaped cushioning material;
Is formed in half along the length direction;
The fixing part of the cable is on the outside or inside of the fastening member.
Providing blocking means for preventing detachment; fastening parts
In the through hole for the cable of the material,
Providing a protective cylinder for protecting the thread of the leave;
The through hole of the deflector is an opening at the fixing end of the cable.
There is a relief part to prevent the cable from being scratched.
It includes that it is.

According to the present invention, there is provided an apparatus for preventing a bridge from falling, wherein at least one of the movable structures is a movable structure, and a fixing means having a cable fastening member provided at each end of the opposed structure; It consists of a cable installed between the fixing means,
An elastic means having a large deformation amount for tensioning the cable is provided between an end of the cable and a fixing member of at least one of the fixing means. In addition, the elastic means having a large deformation amount for tensioning the cable is one of a spring and a rubber packing or a combination of both; a spring as the elastic means is a support for contacting both ends thereof. Sandwiched between pressure plates,
A counterbore for the coil spring is provided on at least one of the support plates.

According to the bridge fall prevention device of the present invention, when an external force applied to a bridge girder due to an earthquake or the like, for example, when at least one of the adjacent bridge girder or the girder and the abutment is a movable structure, the bridge girder is prevented from moving. Even when one of the cables moves in the longitudinal direction, the direction perpendicular to the longitudinal direction, or one of the bridge girders falls from the pier, the end of the cable with respect to the fixing member of the fixing device as the fixing means. Since the parts are always maintained substantially orthogonal by the deflecting device, only the axial force in the tensile direction acts without generating bending deformation force or shearing force on the fastening member.

The deflecting device is divided into two parts, which facilitates the work of attaching the cable to the fixing device. In addition, since the deflecting device has a relief portion at one end side opening, the deflecting device can be connected to the edge. Scratching of the cable due to sliding contact is prevented, and furthermore, the threaded portion of the sleeve at the end of the cable is protected by the protective cylinder provided on the fixing member of the fixing device without crushing the thread, Even when the sleeve moves due to expansion and contraction of the bridge girder due to temperature change and external force, it can smoothly slide in the through hole.

By providing an elastic means such as a spring or rubber packing between the end of the cable and the fixing member of the fixing means, the tension of the cable is maintained even when an adjacent bridge girder abnormally approaches. The structure prevents slacking and also supports a large amount of movement until the bridge girder falls.
The impact force when the bridge is dropped is also reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. Note that, for easy understanding, portions corresponding to the conventional example are denoted by the same reference numerals as the conventional example.

The first embodiment of the present invention, as shown in FIGS. 1 to 5, is provided on the side walls of bridge girders 2 and 3 as movable buildings placed adjacent to each other on a pier 1. Fixing means 15 and 16 made of metal (for example, steel) are fixed to each other by bolts 6a and 7a as fixing means. However, when a large rotational force is applied around the axes of the bolts 6a, 7a, the fixing devices 15, 16 become rotatable.

A through hole through which the cable 10 is inserted is provided at substantially the center of the fixing members 15a and 16a of the flat plate members opposed to the fixing members 15 and 16.

Further, a cylindrical protective cylinder 22 made of metal or synthetic resin is fitted into the through-hole with both ends protruding. The protective cylinder 22 and the fastening member 15
The through holes a and 16a are in a loosely fitted state.

A bundle of PC steel strands (for example, φ12.7 m
As shown in FIG. 4, there is an apartment 13 which is a metal sleeve fixed by caulking, as shown in FIG. A thread groove is engraved on the outer periphery of 13.

The apartment 13 has a cable
The half nut 20 and the elastic member 21 as the movement preventing means 19, which are the means for preventing the fixing portion from being detached, are screwed or fitted to the end of the socket cover 14 respectively.

The material of the elastic member 21 is rubber elastic packing, or a coil spring 21a as shown in FIGS. 5A and 5B, or an elastic packing of the elastic member 21 and the coil spring 21a. Is also used.

Then, the fixing devices 15 and 16 disposed opposite to each other.
The cable 1 is attached to the protection cylinder 22 of the fastening members 15a and 16a.
The condominiums 13 at the end of 0 are inserted.

Further, as shown in FIG. 2, an elastic sponge 11c made of a synthetic resin and a rubber sponge 11c are used as a cushioning material 11 at the outer periphery of the apartment 13 projecting from the fastening members 15a and 16a. The hard packing 11b and the metal supporting plate 11a are sequentially fitted.

Thereafter, the fixing nut 12 is screwed into the threaded portion from the end of the outer peripheral portion of the apartment 13 so that the elastic sponge 11c is 3/4 to 2/2 of its unloaded thickness.
Then, the fixing nut 12 is tightened and fastened until the fixing nut 12 is pressed into a state where the fixing nut 12 is compressed to a degree of 3.

Thus, the cable 10 is installed without being loosened by the elastic force of the telescopic sponge 11c. When a large moving amount (deformation amount) is required in place of the telescopic sponge 11c when the bridge is dropped, as shown in FIGS. Press plate 1
A coil spring 11d is interposed between 1a and 11a, a coil spring 11d is interposed between the support plate 11a on the fixing nut 12 side and the cushioning material 11, and a coil spring 11d is used. A rubber packing or a sponge may be used together and interposed in parallel.

After the cable 10 is laid over the fixing devices 15 and 16 as described above, the brackets 15b and 1 of the fixing devices 15 and 16 which are opposed to each other along the cable 10 are provided.
Deflectors 17, 17, which are a kind of guide blocks, are inserted between 5 c, 16 b, 16 c so as to surround the outer periphery of the cable 10, and fixed by bolts 18.

The deflecting device 17 is formed in two parts, as shown in FIGS. 2 and 3, forming a through-hole opened at both ends, and an opening at one end thereof is slightly formed along the outer periphery of the cable 10. The opening at the other end is larger in diameter than the opening at the one end.

The portion whose diameter is increased to the opening on the other end side is a trumpet-shaped curved surface 17a whose diameter increases toward the opening end. In order to prevent scratches due to sliding contact with the edge of the opening end, a relief portion 17b that is difficult to contact with the cable 10 is provided at the opening on one end side of the through hole (see FIG. 14). The shape of the escape portion 17b is tapered or curved in cross section.

Since the deflecting members 17 and 17 are divided into two parts, one of the deflecting members 17 may be attached to the fixing members 15 and 16 in advance when the cable 10 is laid.

The curved surface 17a is connected to at least the cable 1
The curved surface is formed with a minimum radius of curvature R that can be bent without difficulty, or with a radius having a dimension equal to or larger than the minimum radius of curvature R. Further, the curved surface 17a is continuously connected to the one end side opening portion by a tangent line.

Further, the expansion of the diameter by the curved surface 17a is started in the middle of the one end opening and the other end opening in the through hole of the deflector 17 (see FIG. 2). However, this does not prevent the diameter expansion by the curved surface 17a from immediately starting from the one end side opening.

The deflecting device 17 is made of a relatively hard material such as a synthetic resin (for example, polyethylene, polystyrene, or hard rubber) or a metal (for example, iron or steel). In the case of synthetic resin or hard rubber,
It is not always necessary to form the trumpet-shaped curved surface 17a and the relief portion 17b.

The surface of the curved surface 17a may be covered with a rubber cover having a uniform thickness, so that damage to the cable 10 itself such as scratches due to contact of the cable 10 is prevented. It is preferable.

Next, the movement preventing means 19, as shown in FIG. 2 or FIG. 6, to the mobile due to temperature changes of the building
In a normal temperature state (for example, when the temperature is 25 ° C.), a setting is made such that a required gap α is secured between the end face of the fastening member 15 a and the end face of the elastic member 21.

Thus, in a state where the cable 10 is laid on the bridge girders 2 and 3, considering the elongation of each member due to the outside air temperature around the bridge girders, as shown in FIG. A gap α is secured between the elastic member 21 of the fixing member 15 and the elastic sponge 11c.
It is pressed at 5a and contracted by about 1/4 to 1/3 of the entire length to have a length of δ1.

When the ambient outside air temperature is low, for example, in winter, as shown in FIG. 7, the bridge girders 2 and 3 shrink to each other to increase the interval, and the elastic sponge 11c is
It is pressed by the fastening member 15a that moves to the side 1b, and contracts to about の of the entire length to have a length of δ2. Further, the gap between the movement preventing means 19 and the elastic member 21 is wider than α.

Further, in the case where the ambient outside air temperature is high, for example, in the summer season, as shown in FIG. 8, the bridge girders 2 and 3 extend from each other to reduce the interval therebetween, and the fastening member 15a moves toward the movement inhibiting means 19. The telescopic sponge 11c is fully extended to have an overall length of δ3.

Then, the end surface of the fastening member 15a and the end surface of the elastic member 21 of the movement preventing means 19 are in contact with each other, and the gap α is substantially zero.

As described above, the bridge girders 2 and 3 repeat expansion and contraction due to changes in the ambient temperature such as seasons, but the cable 10 is loosened between the fixing members 15 and 16 by the elastic force of the expansion and contraction sponge 11c of the cushioning material 11. There is no thing.

Even if one of the bridge girders 2 and 3 slips off the pier 1 due to the occurrence of a large earthquake by the bridge fall prevention device according to the first embodiment, as shown in FIG. The bridge girder 3 is held by the cable 10 without falling to the ground, and the end of the cable 10 is maintained in an orthogonal state with respect to the fastening members 15a, 16a by the deflecting members 17, 17, so that the fixing device 15 , 16 and the fastening members 15a, 16a only act on the axial force.

Therefore, the fixing members 15 and 16 and the fastening member 1
No bending force is generated at 5a and 16a, only axial force acts,
The cable 10 is not subjected to an excessive bending force or shearing force, but is subjected to an axial tensile force.
This is a preferable state without any obstacle such as scratching or crushing of the screw portion on the outer peripheral portion of the apartment 13 at the end of 0.

Further, since the protective cylinder 22 is provided in the through holes of the fastening members 15a and 16a, the movement of the fastening members 15a and 16a due to a change in ambient temperature may cause the apartment 1 to move.
The crush of the screw thread of the screw portion at the outer peripheral portion of 3 is prevented.

Also, in the deflecting device 17, the relief of the opening at one end of the through hole is provided, so that the cable 10 is prevented from being scratched due to the sliding contact.

Even when the bridge girders 2 and 3 approach abnormally due to irregular shaking during an earthquake, or when the temperature is high in summer, the so-called severe heat, the apartment 13 and the socket cover 14 of the cable 10 are all fixed. Member 15
The apartment 13 and the socket cover 14 come out of the through holes of the a and 16a, and the fastening member 1
The movement preventing means 19 prevents the through holes 5a and 16a from being returned to the original position by being caught by the edges of the through holes.

Further, as shown in FIGS. 5A and 5B,
If the coil spring 11d is used, the structure corresponding to the large moving amount of the bridge girder is prevented, the slack of the cable 10 is prevented, and the impact force at the time of dropping the bridge is reduced. In addition,
If the coil spring 11d is a conical coil spring as shown in FIGS.
Since the coils do not overlap each other when d is compressed, a large moving amount is secured, which is preferable.

As a second embodiment of the present invention, as shown in FIG. 10, for example, when there is a parking zone on a part of a motorway, the bridge girders 2 and 3 are bridged by being relatively shifted. There is.

Also in this case, the cable 10 is fixed to the fixing members 15a, 16 by the deflection members 17 of the fixing members 15, 16.
a is maintained perpendicular to the fixing member 1.
It can be set so that only the axial force of 5a, 16a and the cable 10 acts. The same operation and effect as those of the first embodiment can be obtained.

Next, according to a third embodiment of the present invention, as shown in FIG.
In the case where there is a hole 5, since it is troublesome and difficult to provide a through hole in the cross beam, fixing devices 15 and 24 are provided on the side walls of the main beams 23 and 24.
At the same time, the guide members 26 are attached to the lower surfaces of the cross beams 25, 25, and the cable 10 is inserted through the guide members 26 so as to bridge between the fixing members 15, 16.

As shown in FIG. 12, the structure of the guide member 26 is such that a guide tube 27 having an inner diameter larger than the diameter of the cable 10 to be erected and the condominium 13 is welded to the column 28 and supported. To the base 29 by welding.

Then, the guide member 26 is connected to the horizontal beam 25,
It is fixed to the lower surface of the bolt 25 with bolts 30. Further, one end of the guide tube 27 is projected from the side surface of the cross beam, and the projected portion is bent along the minimum bending radius of the cable 10.

Further, as shown in FIG. 13A, a slit 27a is provided at the opening end of the portion of the guide tube 27 protruding from the side surface of the cross beam, so that the opening end can be freely formed by the cable 10. You may bend.

As another example of the third embodiment, FIG.
As shown in (b), instead of the guide tube 27, a guide tube 31 is fixed to the guide member 26 in advance as a split guide tube 31 and 32, and is placed on the cable 10 after disposing the cable 10. The guide tube 32 is mounted as described above, and bolts and nuts are fastened to the flange portion to fix the guide tubes 31, 32.

According to this other example, since the cable erection work can be performed without inserting the apartment 13 of the cable 10 into the guide tube, work efficiency is improved, and the inner diameter of the guide tubes 31 and 32 is adjusted to the outer diameter of the cable 10. Apartment 1 larger than the outer diameter of the cable 10
It is not necessary to make the inside diameter large according to 3, and it becomes compact.

A fourth embodiment of the present invention will be described with reference to FIGS.
As shown in the figure, between the fixing nut 12 and the fixing member 15a, between the fixing nut 12 and the fixing member 15a, outside the fixing member 15a of each of the fixing devices 15 provided at the opposite ends of the adjacent bridge girders,
In order to improve the work of mounting the coil spring 11d (in this example, a conical coil spring) sandwiched between 1a, 11a, counterbore plates 11e, 11f for the coil spring are provided on the support plates 11a, 11a.

After the condominium 13 of the cable 10 is inserted into the through hole of the fastening member 15a by the counterbore 11e, 11f, the hard packing 11b as the cushioning material 11 and the supporting plate 11a are moved toward the fastening member 15a. Then, the coil spring 11 d is inserted into the apartment 13.
At the time of mounting, the end of the coil spring 11d fits in the counterbore 11f, and can be easily positioned and mounted without being shifted with respect to the axis of the apartment 13.

Then, the next support plate 11a (smaller one) is fitted into the apartment 13 and this also has a counterbore 11e.
Is fixed to the end of the coil spring 11d, and the fixing nut 12 is tightened to a required position.
A hexagonal screw 12a is screwed from the side of the fixing nut 12 to prevent the nut from rotating. The present invention is not limited to this embodiment, and a double nut may be used as a detent (not shown).

In this embodiment, the counterbore is provided on both the support plates. However, the present invention is not limited to this. For example, at least the support plate 11f is provided only on the support plate 11a of the cushioning material 11. A counterbore may be provided on one of 11a and 11a.

The hard packing 11b and the supporting plate 11a
May be integrated beforehand by baking or using an adhesive or the like to reduce the number of assembly work steps and facilitate component management.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
The present invention relates to improvement in workability when the apartment 13 of No. 0 is inserted into, for example, the fastening member 15a of one fixing tool 15.

For example, as shown in FIGS.
Brackets 15b and 15 arranged opposite to fixing device 15
c and the brackets 15h, 15f, 15g, which are bridged between them and fixed by means such as welding,
A rectangular space is formed, and the deflectors 17 and 1 are formed in the space.
7 and the deflectors 17, 17 and the bracket 15
b and 15c are fixed with bolts.

The brackets 15f and 15g are:
Brackets 15b and 15c are not integrated but separate.
And a notch 15j is provided so as to be opposed to each other.

The notch 15j is formed to have a width that allows the cable 10 (including the apartment 13) to be moved in and out.

FIG. 17 (a) is formed by the notch 15j.
When the cable 10 is installed between the fixing devices 15 and 16 fixed to the ends of the adjacent bridge girders, for example, first, one end of the cable 10 (a condominium 13) is first fixed to the fixing device 16 side as shown in FIG. The member 16a is inserted.

Next, the other end of the cable 10 is connected to the fixing member 1.
As shown in FIG. 17 (b), when the user intends to insert the apartment 5a, the end of the apartment 13 is brought as close as possible to the fastening member 15a because of the notch 15j.

Then, the cable 10 can be bent gently and lowered as shown by the arrow in the figure, and the apartment 13 can be easily inserted into the through hole of the fastening member 15a.

Therefore, the worker can perform the insertion work without bending the cable 10 greatly, so that the burden is reduced and the workability is improved.

On the other hand, for example, as shown in FIG.
When the bridge is bridged by an integral object (when the brackets 15f and 15g are integrated and the notch 15j is not provided), the tip of the apartment 13 at the other end of the cable 10 is a space between the bracket 15m and the bracket 15h. Therefore, it is necessary to draw the condominium 13 on the other end side toward the fixing device 16 by the length L in the drawing.

Therefore, since the cable 10 is bent and inserted so that the cable 10 is inserted, the operation is intensive for the operator, and the work efficiency is reduced. Thus, by providing the notch 15j in the fifth embodiment, the workability of the cable erection work is improved.

In the sixth embodiment of the present invention, as shown in FIG. 18, the fastening members 15a,
A metal adjusting cap 20a is provided outside the cable 16a as a cable movement preventing means 19a, surrounding the fixing nut, the cushioning material 11, the coil spring 11d, etc., with a required gap from the front end surface of the apartment 13. It is.

The adjustment cap 20a is fixed to the fastening member 15a by a bolt or the like at a flange portion provided at an end thereof, and is a circular or rectangular cylindrical body. Good.

A packing 21b made of rubber or the like is attached to the inside of the adjustment cap 20a at a position where the end of the condominium 13 abuts. Note that the fixing cap 20a and the packing 2 are similarly provided on the fixing unit 16 side.
1b is mounted.

The movement preventing means 19a allows the part of the apartment 13 and the socket cover 14 to be fixed to each other even if the adjacent bridge girder approaches abnormally due to the extreme heat in summer or abnormally approaches due to an earthquake or the like. It is prevented from going outward from the through hole of the fixing member 15a or the fastening member 16a.

As described above, the movement preventing means 19a according to the sixth embodiment is provided outside the fastening members 15a, 16a with respect to the movement preventing means 19 in the first embodiment. There is a cross girder between the bridge girder where
When making a hole in the cross beam and inserting the cable 10,
The movement preventing means 1 of the first embodiment is provided in the apartment 13 part.
This is because if there is a 9, there is a disadvantage that it is difficult to insert the hole into the cross beam and the hole must be enlarged.

The movement preventing means 19 in the sixth embodiment.
In the case of a, the cable 10 can be attached after being laid between the fixing tools 15 and 16. As a result, the workability of erection of the cable is improved.

As described above, the first to sixth embodiments have been described. However, when the fixing members 15 and 16 are mounted on the bridge girder, they may be rotatably mounted with pins as in the conventional case. Alternatively, it may be fixed by a plurality of bolts and nuts so as not to rotate.

[0079]

As described above, in the bridge fall prevention device according to the present invention, at least one of the movable structures is a movable structure, and the cable stopper provided on each of the opposed ends of the opposed structure is provided. Fixing means having a fixing member, a cable provided between the fixing means , and a through-hole through which the cable is inserted.
And a deflector provided near the fixing end of the cable.
The deflection device is always affected by the cable
Affected by cables only in emergency without being affected
Deflector installed in the emergency room and affected by the cable in an emergency
The through hole is on the fixing end side of the cable,
Maintain the cable in a direction substantially perpendicular to the fastening member
On the opposite side of the building
Bending stress and shear force that are suddenly applied to
To avoid over-concentration.
Since it is formed on a curved surface with a radius of curvature, even if an external force such as an earthquake applies bending force to the cable of the bridge prevention device,
The cable bends along the curved surface of the deflector, so that no excessive bending stress or shearing force is generated on the cable, preventing the bridge girder from falling to the ground and preventing the cable end from being scratched or broken. It has excellent effects.

Even if the cable is bent in any direction, the cable is always maintained perpendicular to the fixing member of the fixing device by the deflecting device, and the bending force due to the external force is applied to the fixing member of the fixing device. It has an excellent effect that only the axial force is transmitted without being transmitted.

The deflecting device extends along the length direction of the deflecting device.
By splitting into two parts, an excellent effect that the construction of the bridge prevention device becomes easy can be achieved.

Since the radius of curvature of the curved surface of the deflecting device is equal to or larger than the minimum bending radius of the cable, even if a bending force is applied to the cable, no large bending stress is generated, and a local shear stress acts. Since it does not, it has an excellent effect of improving the proof stress at the time of breaking.

A relief portion is provided at one end of the through hole of the deflector so that the cable is not damaged by scratches or the like due to sliding contact due to movement of the bridge girder. It has an excellent effect of improving.

In addition, since the movement preventing means for preventing the cable from being pulled out is provided at the end of the cable on the side opposite to the fixing member of the fixing means, even if the adjacent bridge girder abnormally approaches during an earthquake. In addition, there is provided an excellent effect that an adverse effect such that the apartment and the socket cover at the end of the cable do not come out of the through hole of the fastening member and do not return to the original state is prevented.

Further, if the movement preventing means is provided on the outside of the facing fixing member, even if there is a cross beam between the fixing tools, the movement preventing means can be easily attached after the cable is laid, and the workability is improved. The effect is improved.

Since the fixing member of the fixing means is provided with a protective cylinder for protecting the thread portion of the sleeve (mansion) fixed to the end of the cable, when the bridge girder expands and contracts due to a temperature change,
Alternatively, even when the bridge girder is complicatedly shaken by an external force, the condominium can smoothly move through the through-hole through the protective cylinder without the screw coming into contact with the fastening member, and the screw portion and the fastening member can pass through. This provides an excellent effect that the collapse of the screw thread due to the collision with the wall surface of the hole can be prevented.

[0087] An apparatus for preventing a bridge from falling according to the present invention comprises: a fixing means having at least one movable structure and a cable fastening member provided at each end of the opposing structure;
An elastic means having a large deformation amount for tensioning the cable is provided between an end of the cable and a fixing member of at least one of the fixing means. Therefore, for example, even if the adjacent bridge girder approaches abnormally, the tension of the cable is maintained to prevent loosening, and the structure is designed to cope with a large amount of movement until the bridge girder falls, It has an excellent effect of reducing power.

Further, the elastic means having a large amount of deformation for tensioning the cable may be a spring or a rubber packing or a combination of both, so that the design is adapted to alleviate the impact force at the time of dropping a bridge. the degree of freedom is an excellent effect say that to increase.

[Brief description of the drawings]

FIG. 1 is a partial side view of a first embodiment of a bridge prevention device according to the present invention.

FIG. 2 is an enlarged side view of a fixing portion of the bridge fall prevention device according to the first embodiment.

FIG. 3 is an enlarged front view of a fixing portion of the bridge fall prevention device according to the first embodiment.

FIG. 4 is a front view of a cable end;

FIG. 5 is a front view of the embodiment, in which the cushioning material and the elastic material are coil springs, and FIG. (B) is a front view in the case where.

FIG. 6 is an explanatory view showing a stretched state of a stretchable sponge of the cushioning material according to the first embodiment.

FIG. 7 is an explanatory view showing a stretched state of a stretchable sponge of the cushioning material according to the first embodiment.

FIG. 8 is an explanatory view showing an expanded and contracted state of an elastic sponge of the cushioning material according to the first embodiment.

FIG. 9 is an explanatory diagram illustrating an operation of the device for preventing a fallen bridge according to the first embodiment during an earthquake.

FIG. 10 is a plan view of a bridge prevention device according to a second embodiment of the present invention.

FIG. 11 is a side view according to a third embodiment of the present invention.

FIG. 12 is a longitudinal sectional view of a guide member in the third embodiment.

FIG. 13 is a front view (a) of an end portion of a guide tube and a vertical cross-sectional view (b) of a guide tube according to another embodiment.

FIG. 14 is a side view showing, on an enlarged scale, a portion of a bridge prevention device according to a fourth embodiment of the present invention.

FIG. 15 is a perspective view of a bridge prevention device according to a fourth embodiment and a fifth embodiment of the present invention.

FIG. 16 is a side view of a fixing device in a bridge-fall prevention device according to a fifth embodiment of the present invention.

FIGS. 17 (a), (b), and (c) are illustrations showing the use state of the bridge prevention device according to the fifth embodiment of the present invention.

FIG. 18 is a side view of a bridge prevention device according to a sixth embodiment of the present invention.

FIG. 19 is a side view of a bridge-fall prevention device according to a conventional example.

FIG. 20 is a perspective view of a fall prevention device according to the conventional example.

FIG. 21 is a side view of the fall prevention device according to the conventional example.

FIG. 22 is a longitudinal sectional view of an end of the cable.

FIG. 23 is an explanatory diagram of an operation state at the time of an earthquake by the fall prevention device according to the conventional example.

[Explanation of symbols]

1 bridge pier, 2, 3 bridge girder, 10 cable, 11 cushioning material, 11a supporting plate, 11b hard packing, 11c telescopic sponge, 11d coil spring, 11e, 11f counterbore, 12 fixing nut, 13 sleeve (mansion), 14 socket cover , 15, 16 fixing device, 15a, 16a fastening member, 15b, 15c, 15f, 15g, 15h bracket, 15j notch, 17 deflecting device, 17a curved surface, 19, 19a movement inhibiting means, 20a adjustment cap, 21 elastic material , 21a coil spring, 21b packing, 22 protective cylinder, 23, 24 main girder, 25 horizontal girder, 26 guide member, 31, 32 guide tube.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akiyoshi Suzuki 1-3-6 Nishikanda, Chiyoda-ku, Tokyo Intranet Co., Ltd. (72) Inventor Koichi Oikawa 1-3-6 Nishikanda, Chiyoda-ku, Tokyo (56) References JP-A-4-258403 (JP, A) JP-B-52-34135 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) E01D 19 / 04 E01D 19/04 101

Claims (8)

(57) [Claims] At least one is a movable building, and a fixing unit having a cable fastening member provided on each of the opposed end sides of the opposed building; A cable provided with a through-hole through which the cable is inserted , and
It consists of a deflecting device provided near the end, and the deflecting device is not always affected by the installed cable.
In an emergency only installed in the condition affected by the cable
The deflector, which is affected by the cable in an emergency,
However, on the fixing end side of the cable,
It is formed in a shape that is maintained in a direction substantially perpendicular to the fastening member.
On the opposite building side,
Extremely applied bending and shear forces are not locally concentrated
Cable with a radius of curvature equal to or greater than the minimum bending radius of the cable.
A bridge prevention device characterized by being formed on a curved surface . 2. The cable which has been erected in an emergency, against a sudden impact which is suddenly applied.
A relaxation means for expanding and contracting is provided on the fixing end side.
Girder prevention device according to claim 1, wherein the door. 3. A resilient means provided between a fastening member and a fixing end of a cable , the relieving means for expanding and contracting the cable.
The fall prevention device according to claim 2, wherein: 4. An elastic means comprising : a conical coil spring for ensuring a large amount of expansion and contraction; and a plate-shaped buffer attached to a support plate for the conical coil spring.
The material according to claim 3, wherein the material is made of a material.
Bridge collapse prevention device. 5. The deflecting device is formed in two parts along the length direction.
The bridge fall prevention device according to claim 1 . 6. A cable outside or inside the fastening member.
Blocking means to prevent the fixing portion of the
It, girder prevention device according to claim 1, wherein the. 7. A cable is provided in a through hole for a cable of a fastening member.
Protective sleeve to protect the thread of the sleeve fixed to the end
The provided things, girder prevention device according to claim 1, wherein the. 8. The through hole of the deflecting device is provided at a fixing end of the cable.
Openings on the side prevent the cable from being scratched
The fall prevention device according to claim 1 , wherein a relief portion is provided .