JP2001003316A - Bridge fall prevention buffer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bridge fall prevention buffer capable of effectively making buffer action function even when angle displacement of a joint cable is made in an arbitrary direction by displacement or deformation added to the joint cable by impact force due to earthquake or the like. SOLUTION: A bridge fall prevention buffer 1 is so constituted that it is provided between an abutment 22 and a bridge girder 25 borne on the abutment 22, and both end sections 2a and 2b of a joint cable 2 in the bridge fall prevention buffer 1 are respectively borne on buffer constitutive sections 3 so that both end sections can have buffer action along the direction of its axis. Then, these buffer constitutive sections 3 are respectively pivoted on a bracket 24 provided in the abutment 22 through a base plate 13 as a bearing member and a bracket 26 provided in the bridge girder 25, and one bearing section 6 is formed by combining a bearing 9 providing a spherical shaft 11 to a bearing pin 10 with an outside wheel 7 having a spherical inside sphere fitting the spherical shaft 11 of the bearing 9 thereto in a slidable manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock-absorbing device provided between adjacent bridge girders or between a bridge girder and a pier so that the connecting cable can be freely displaced in an arbitrary direction. .

[0002]

2. Description of the Related Art When an earthquake occurs, an impact force due to its high energy acts on the bridge structure, and the bridge structure is damaged by a vibration based on the impact force, such as a dropped bridge, thereby causing great damage. To cope with this, hitches for preventing a bridge from falling have been conventionally installed between bridge girders or between a bridge girder and a pier. In the conventional shock absorber for preventing a bridge from falling, a buffering component is provided at both ends of a connecting cable such as a PC steel cable, a steel bar, or a tubular connecting rod, and the buffering component is connected to a bridge girder or a pier via a bracket. Is what you do. Also,
The above-mentioned buffer component generally has a configuration in which a spring and a buffer member such as elastic rubber are combined. According to this shock absorber for preventing a bridge from falling, when a horizontal movement occurs in a bridge girder or the like, when an impact force acts in the axial direction of the connecting cable, the shock absorber acts to absorb the impact force. This prevents damage such as a dropped bridge.

[0003]

However, when a large earthquake occurs, a complicated vibration action occurs on a bridge pier or the like, and a displacement or deformation beyond expectation is applied to the bridge girder or the pier. For example, the connecting end of the bridge girder may be displaced vertically or vertically in this horizontal plane with respect to the tension horizontal direction of the connecting cable. At this time, the impact force due to the earthquake is applied in a direction inclined with respect to the axis of the connecting cable, which may cause an angular displacement of the axis of the connecting cable.

In order to cope with this, in the conventional shock absorber for preventing a bridge from falling, support portions are provided at both end portions for fixing the buffer components at both ends thereof, and the support portions are attached to a support shaft (pin) on a bridge of a bridge girder or a pier. In this case, a configuration was adopted in which the shaft was pivotally supported. This conventional pivoting arrangement can deal only with the case where the axis of the connecting cable is angularly displaced in a predetermined direction such as a vertical direction. In particular, bridges such as abutments have no space for installing brackets in the same plane as the flange of the bridge girder, so when connecting from the pier to the bridge girder, the shock absorber for preventing falling bridges is inclined in the vertical plane. The configuration supported by the shaft was adopted.

[0005]

For this reason, in the conventional connection structure of the shock-absorbing device for preventing a bridge from falling, the connecting cable portion can swing through the support shaft in the vertical plane, but it can swing in the horizontal plane. Cannot be moved. However, the displacement and deformation applied to the connection cable due to the impact force due to an earthquake or the like are not necessarily limited to a specific direction,
The angular displacement occurs in any direction. Therefore, when the connecting cable is displaced in a direction other than the set direction, or when an impact force is applied in a direction in which the connecting cable is deformed, the conventional support structure of the shock absorber for preventing falling bridge cannot sufficiently cope. However, it was not possible to avoid damage to the shock absorber for preventing falling bridges, and further, occurrence of falling bridges and the like.

Therefore, according to the present invention, even when the connecting cable portion is angularly displaced in an arbitrary direction due to displacement or deformation applied to the connecting cable portion by an impact force due to an earthquake or the like,
An object of the present invention is to provide a shock-absorbing device for preventing a bridge from falling, which can effectively exhibit the shock-absorbing action.

[0007]

In order to achieve the above-mentioned object, the present invention provides a shock-absorbing device for preventing a bridge from falling, which is provided between adjacent bridge girders or between a bridge girder and a pier. The connecting cable in the shock absorber for dropping bridge prevention is supported by a buffering component so that both ends thereof can receive a buffering action along the axial direction, and these buffering components are connected via a bearing member. A bracket is provided on the bridge girder or the pier, and at least one of these bearings is provided with a support shaft having a spherical shaft and a spherical surface on which the spherical shaft of the support shaft is slidably fitted. The outer ring having a shaped inner spherical surface is combined with the outer ring, and the spherical axis slides on the inner spherical surface of the outer ring so that the axis of the connection cable can be angularly displaced in any direction. And butterflies.

In the shock absorber for preventing a bridge from falling according to the present invention, the shock absorbing component acting in the axial direction of the connection cable is absorbed by the shock absorbing component provided with respect to the displacement and deformation applied to the connection cable, and the connection is prevented. With respect to the angular displacement of the cable shaft in an arbitrary direction, a combination of a support shaft having a spherical shaft and an outer ring having a spherical inner spherical surface on which the spherical shaft of the support shaft is slidably fitted. By the supporting shaft part,
The impact force is prevented from being applied to the drop-prevention shock absorber.

The position of the spherical shaft on the above-mentioned support shaft is not particularly limited as long as the above-mentioned function is exerted. It is preferably provided at the center. The support shaft can be formed by inserting a support pin into a through hole provided in the spherical shaft member. In this case, the spherical shaft member does not need to be particularly fixedly provided on the spindle pin, and may be in a floating state.

The outer ring may be configured such that the support shaft is integrated with the spherical shaft previously fitted in the inner spherical surface, but the outer ring portion divided into two is combined. It may be configured to be integrated. In this two-part configuration of the outer ring, a semi-spherical inner spherical surface can be formed in a symmetrical shape on each of the opposing surfaces of the outer ring portion.

[0011] In addition, the support shaft structure according to the combination of the support shaft having the spherical axis and the outer ring is sufficient if at least one of the support shaft portions is provided in the shock absorber for preventing a bridge from falling. When provided on both of the support shafts, it is possible to cope with a wider range of angular displacement. Further, it is preferable that the angular displacement of this one support shaft is set so that the opening angle is 30 ° or more.

[0012] Further, the shock-absorbing component of the shock-absorbing device for preventing a bridge from falling
For the support shaft portion according to the above combination, the support shaft may be connected and fixed to the support shaft via a connecting member, but the support shaft connected to the outer ring via the connection member and having a spherical shaft is provided. It may be configured to be fixedly supported by the bracket. According to the latter configuration, it is possible to separately handle the main body portion of the shock-absorbing device for preventing a bridge from falling while the long support shaft is attached to the bracket, so that the installation work is facilitated. There are advantages.

[0013] In addition, in the structure in which only one support shaft structure is provided for the fall-prevention shock absorber, the support shaft structure relating to the combination of the support shaft having a spherical shaft and the outer ring is provided. What is necessary is just to make it the pivot support structure which can swing only in the specific direction similar to the conventional structure mentioned above.

In the present invention, the pier is a broad concept including an abutment. In addition, as for the buffer component of the shock absorber for dropping bridge prevention, as long as the function of absorbing the impact force acting in the axial direction of the connection cable described above is used, the conventional spring and the buffer member such as elastic rubber are used. Various configurations including a combined configuration can be adopted. The connection cable includes various types such as a PC steel cable, a steel rod, and a tubular connection rod.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a dropping prevention buffer according to an embodiment of the present invention will be described with reference to the drawings. The shock-absorbing device 1 for preventing a bridge shown in FIGS. 1 and 2 is a shock-absorbing device for preventing a bridge from being provided between an abutment 22 and a bridge girder 25 supported by the abutment 22.

The connecting cable 2 of the shock-absorbing device 1 for dropping bridge is supported by a shock-absorbing component 3 so that both ends 2a and 2b can be shocked along its axial direction. The component 3 is supported by a bracket 24 provided on the abutment 22 and a bracket 26 provided on the bridge girder 25 via base plates 4 and 13 as bearing members, respectively. A support shaft 9 having a spherical shaft 11 provided thereon and an outer ring 7 having a spherical inner spherical surface 7c on which the spherical shaft 11 of the support shaft 9 is slidably fitted.

As shown in FIG. 3, the outer race 7 has an outer race 7a.
And an outer ring portion 7b. These outer ring portions 7
A semi-spherical inner spherical surface 7c is provided at the center of the opposing surface of the outer ring portion 7b, and a concave groove 7d extending between the opposing surfaces through the inner spherical surface 7c is formed in a symmetrical shape.

Further, the support shaft 9 is provided at the center position of the support pin 10 in a floating state by simply inserting the support pin 10 into the through hole 11b of the spherical shaft 11. . 11a is a bearing part which protects the edge of the through-hole 11b. Also, screw portions 10a are formed at both ends of the support pin 10, and these screw portions 10a are formed.
Are screwed with locking nuts 12, respectively.

Further, the support shaft 9 is inserted into the bracket 24, is fixed with the washer and the nut 12, and is further secured with a split pin as a slack stop. The support shaft 9 thus supported is supported by the bracket 24 in a state where it does not rotate. Further, the support nut 9 is formed by each locking nut 12.
Is prevented from moving in its axial direction.

The support shaft 9 has its spherical shaft 11 fitted into the inner spherical surface 7c and the support shaft pin 10 located in the through hole formed by each groove 7d. The parts 7a and 7b are combined and further integrated by the connecting member 8 to form the outer race 7. Thus, the support shaft 6 is configured. In the configuration of the support shaft 6, the outer ring 7 slides on the spherical shaft 11 within the inner spherical surface 7c, so that the axis of the connecting rod 2 can be angularly displaced in any direction.

FIG. 4 shows a displacement state of the outer ring 7 caused by sliding.
This is shown in FIGS. The state shown by the two-dot chain line in FIG.
This is a case where the outer ring 7 is angularly displaced in a vertical plane including the support shaft 9. The state shown in FIG. 5 is a case where the outer ring 7 is angularly displaced in a plane perpendicular to the support shaft 9, and corresponds to a state where the bridge girder 25 is displaced as shown by a two-dot chain line in FIG. Further, the state shown by the two-dot chain line in FIG. 5 is a case where the above-mentioned state is further angularly displaced in a vertical plane including the support shaft 9. Also,
The state shown in FIG. 6 is a case where the outer ring 7 is angularly displaced in a horizontal plane, and corresponds to a state where the outer ring 7 is displaced as shown by a two-dot chain line in FIG.

A base plate 4 is connected to the outer ring 7 side of the outer ring 7 via a connecting portion 5, and the buffering portion 3 is provided in the connecting portion 5. That is, a cylindrical buffer box 17 is provided on the inner surface side of the base plate 4, and a disk-shaped buffer plate 18 is provided in the buffer box 17. The end 2a of the connecting rod 2 is
A coil spring 19 is inserted into the penetrated end 2a, and a support plate 20 is inserted with the coil spring 19 sandwiched between the buffer plate 18 and the end 2a. Further, the support plate 20 is a nut 21
, The buffering component 3 is configured.

Also in the connecting portion 14 connected to the other base plate 13, the buffering component 3 is arranged in the same manner as described above in relation to the end 2b of the connecting cable 2. Therefore, the connection cable 2 is in a state of being bridged between these buffer components 3. The intermediate portion of the connection cable 2 is held by guides 16 provided on the outer surfaces of the base plates 4 and 13, respectively, so that the linear state is maintained.

Therefore, when an impact force is applied in a direction to separate the connecting portion between the abutment 22 and the bridge girder 25, the connecting cable 2
Is in a tension state. In this case, the support plate 20 moves along the axial direction of the connection cable 2 and the coil spring 19 is compressed accordingly. When this impact is relatively weak, the impact is applied to the coil spring 19.
Is absorbed by When the impact force is excessive due to a large earthquake or the like, the support plate 20 collides with the buffer plate 18, but the pressing force at the time of the collision is reduced by the elastic action of the buffer plate 18.

A bracket 26 is provided on the surface of the web portion 25a of the bridge girder 25.
The connecting portion 17 of the base plate 13 is supported by a support shaft 15. 25b is a flange portion of the bridge girder 25. For this reason, the end 2 b of the connection cable 2 is swingable in a horizontal plane by the support shaft 15. This connection 1
The swing configuration in 7 is combined with the above-described configuration in which the support shaft 6 can be angularly displaced in any direction, and enables the entire bridge-fall prevention buffer 1 including the connection cable 2 to be freely angularly displaced. I have.

As shown in FIG. 1, two of the above-mentioned bridge-preventing shock absorbers 1 are provided symmetrically on both side surfaces of the web portion 25a of the bridge girder 25, thereby connecting and buffering the both sides of the bridge girder 25. Is balanced. As shown in FIG. 7 and FIG. 8, such an installation configuration of the dropping prevention buffer 1 is provided for each connecting portion between the bridge girder 25 and the abutment 22 for the entire bridge structure. Further, as shown in FIGS. 6 and 7, the shock absorber 1 for preventing a bridge from falling is a bracket capable of pivotally supporting the support shaft 9 perpendicularly to the surface of the web 25 a of the bridge girder 25 instead of the bracket 24 described above. It can be similarly installed between adjacent bridge girders 25 supported on the piers 23.

[0027]

As described above, since the present invention is constituted, the following effects are exhibited. First, a dropping prevention buffer provided between adjacent bridge girders or between a bridge girder and a pier, and both ends of the connection cable in the bridge hitting prevention buffer are subjected to a buffering action along the axial direction. Respectively, so that they can be supported by a bracket provided on the bridge girder or the pier via a bearing member, and at least one of these bearings is Since the support shaft provided with the spherical axis and the outer ring having a spherical inner spherical surface in which the spherical axis of the support shaft is slidably fitted are formed, the spherical axis is formed by the inner spherical surface of the outer ring. By sliding, the axis of the connecting cable can be angularly displaced in any direction.

Therefore, even if adjacent bridge girders or bridge girders and piers are displaced from each other in an arbitrary direction, the shock-absorbing device for preventing bridges according to the present invention does not cause damage to the connecting structure, and the straight line of the connecting cable is not damaged. In a state where the state is maintained, the buffering action of the buffering component can be effectively functioned.

Further, in particular, according to the structure in which the shock-absorbing component of the shock-absorbing device for preventing a bridge from being dropped is connected to the outer ring via the connecting member, and the support shaft having the spherical shaft is fixedly supported by the bracket. In addition, since the structure of the shock absorber for dropping prevention is reduced in size, the work of installing the shock absorber for bridge dropping in a bridge structure is facilitated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing an installation configuration of a shock absorber for preventing a bridge from falling according to the present invention.

FIG. 2 is a partial cross-sectional plan view of the shock-absorbing device for preventing a bridge from falling;

FIG. 3 is an exploded perspective view of a support shaft portion of the shock absorber for preventing falling bridge according to the first embodiment.

FIG. 4 is a partial vertical cross-sectional side view for explaining the function of a spindle in the shock-absorbing device for preventing a bridge from falling.

FIG. 5 is a partial side view for explaining a function of a spindle in the shock-absorbing device for preventing a bridge from falling.

FIG. 6 is a partial side view for explaining a function of a support shaft portion of the shock absorber for preventing a bridge from falling.

FIG. 7 is a fragmentary cross-sectional side view of the bridge structure provided with the above-mentioned shock absorber for preventing falling of a bridge.

FIG. 8 is a fragmentary cross-sectional plan view of the bridge structure provided with the above-mentioned shock absorber for preventing falling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Falling prevention buffer 2 Connecting cable 3 Buffering component 4 Base plate 6 Support shaft 7 Outer ring 7a, 7b Outer ring 7c Inner spherical surface 7d Groove 9 Support shaft 10 Support pin 11 Spherical shaft 13 Base plate 15 Support shaft 22 Abutment 25 Bridge girder

Claims (2)

[Claims] The present invention relates to a shock-absorbing device for preventing a bridge from falling between adjacent bridge girders or between a bridge girder and a pier. Each of them is supported by a buffering component so as to be able to receive an action, and these buffering components are respectively supported by a bracket provided on the bridge girder or the pier via a bearing member, and at least one of these bearings is supported. One is formed by a combination of a support shaft provided with a spherical shaft and an outer ring having a spherical inner spherical surface on which the spherical shaft of the support shaft is slidably fitted. Wherein the shaft of the connecting cable can be angularly displaced in any direction by sliding. 2. The structure according to claim 1, wherein the shock-absorbing component of the shock-absorbing device for preventing a bridge from falling is connected to the outer race via a connecting member, and a support shaft having a spherical shaft is fixedly supported by the bracket. Shock absorber for falling bridge prevention.