JP5055085B2 - Fall bridge prevention connector - Google Patents

Description

  The present invention relates to a fallen bridge prevention connector that connects a main girder of a bridge and a pier.

Conventionally, there has been a problem that the superstructure of the bridge (bridge girder, floor slab, etc.) falls from the pier due to an earthquake or the like. Therefore, in recent years, in order to prevent the bridge superstructure from falling, a bridge-preventing connector for connecting a bridge pier and a bridge girder or connecting bridge girder arranged in series is provided. There is a structure in which a high-strength chain for ships is embedded in weather-resistant rubber as a fallen bridge prevention connector. This falling bridge prevention connector has a generally curved shape or a straight shape. In addition, the above-mentioned drop bridge prevention connector is embedded in the rubber in a relaxed state. Furthermore, in the above-mentioned bridge-falling prevention tool, both ends of the chain protrude from the rubber. For example, when connecting a bridge pier and a bridge girder, the fall bridge prevention connector having the above-described structure is interposed between the bridge pier and the bridge girder by attaching one end of the chain to the bridge pier and the other end of the chain to the bridge girder. The Thereby, a bridge pier and a bridge girder are connected via a connector for preventing a falling bridge. Even if small vibrations are transmitted to the bridge due to temperature changes, etc., the bridge girder without hindering the function of the support that supports the bridge girder by the rubber elastic force of the falling bridge prevention connector and the shape characteristics of the rubber in the case of a curved shape Follow the movement. Further, when a large displacement occurs in the bridge girder due to a large earthquake or the like, the tensile resistance force by the chain works while the cushioning function by the rubber is exerted, and the fall of the superstructure of the bridge can be prevented (for example, see Patent Document 1) .)
Japanese Patent No. 3713313

  However, the above-described conventional drop-bridge preventing connector has a structure in which the chain moves freely, so that the connector itself can be deformed. For this reason, even if the objects to be connected are displaced relative to each other in the direction of the bridge axis due to live loads of large vehicles, small earthquakes, or expansion and contraction of the bridge girder in the direction of the bridge axis due to temperature changes, etc. It cannot be restricted. Therefore, a displacement limiting structure for limiting the displacement described above must be installed separately, which is complicated for the installer.

  The present invention takes the above-described conventional problems into consideration, and provides a connector for preventing a falling bridge having a displacement limiting function for limiting the relative displacement of the objects to be connected, thereby reducing the installation man-hours. The purpose is to simplify.

The fallen bridge prevention connector according to the present invention has a configuration in which an intermediate portion of a relaxed chain is embedded in an elastic body, and both ends of the chain are attached to each connection object, thereby connecting the connection objects. In the fallen bridge prevention connecting tool that is connected and connects the objects to be connected, at least one set of the links constituting the chain is restrained in the relaxed state, and the links are welded together. It is characterized by being restrained .

With such a feature, the links are constrained to restrict the movement of the chain, and the relative displacement between the objects to be connected due to small shaking is limited. On the other hand, when a large shake occurs due to a large earthquake or the like and the above-described restrained portion is broken, the movement of the chain is allowed. At this time, if the objects to be connected are relatively displaced in a direction in which they are separated from each other, the chain is pulled and a tensile resistance force acts, and the relative displacement in the direction in which the objects to be connected are separated is restricted.
Furthermore, the movement of the chain is restricted by the welded portion, and the displacement between the objects to be connected due to small shaking is limited. On the other hand, when a load exceeding the strength of the welded portion is applied, the welded portion is broken. In this case, the strength of the welded portion is appropriately adjusted by adjusting the area of the welded portion.

Moreover, it is preferable that the said link is restrained via the connection member erected between the said links in the elastic body.

  Thereby, the movement of the chain is restricted by the connecting member, and the relative displacement between the objects to be connected due to the small shaking is limited. On the other hand, when a load exceeding the strength of the connecting member is applied, the connecting member is broken.

  According to the drop-bridge preventing connector according to the present invention, a displacement limiting function for limiting the relative displacement of the objects to be connected can be exhibited, and the trouble of separately installing the displacement limiting structure can be saved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a drop-bridge preventing connector according to the present invention will be described based on the drawings.

[First Embodiment]
First, a first embodiment of the present invention will be described. In the following description, the axial direction of the bridge girder 9 (lateral direction in FIG. 1) is defined as the bridge axial direction.
FIG. 1 is a side view of a drop-bridge preventing connector 1 according to the present embodiment, and FIG. 2 is a perspective view illustrating the internal structure of the drop-bridge preventing connector 1 according to the present embodiment.

  As shown in FIGS. 1 and 2, the drop-bridge preventing connector 1 is for connecting a bridge pier 8 and a bridge girder 9 supported on the bridge pier 8 via a movable support (not shown). Yes, it is a connector that allows the bridge girder 9 to move. The fallen bridge prevention connector 1 includes a chain 3 having one end attached to a bridge pier 8 and the other end attached to a bridge girder 9, and a rubber body 2 covering an intermediate portion of the chain 3. That is, the middle part of the chain 3 is embedded in the rubber body 2.

  The chain 3 is a high-strength metal chain having a configuration in which a plurality of links 30 are connected. If it demonstrates in detail, the chain 3 will consist of the structure which connected the five links 30, and is extended in the state curved in the substantially U shape. The chain 3 is disposed in a relaxed state. That is, each link 30 is arranged with a gap so that the links 30 do not contact each other.

  Of the links 30 constituting the chain 3, the links at both ends (terminal links 31 </ b> A and 31 </ b> B) are embedded in the rubber body 2 at the center side of the chain, and the remaining part on the chain end side of the rubber body 2. It protrudes from the end face and is exposed. A portion on the chain end side of one end link 31 </ b> A protruding outside the rubber body 2 is attached to a pier side bracket 10 fixed to a side surface of the pier 8 via a pin 11. Further, the portion on the chain end side of the other end link 31 </ b> B protruding outside the rubber body 2 is attached to a bridge girder side bracket 12 fixed to the bottom surface of the bridge girder 9 via a pin 13.

  On the other hand, the links (intermediate links 32A, 32B, 32C) provided between the terminal links 31A, 31B are embedded in the rubber body 2 throughout. More specifically, in the rubber body 2, the intermediate links 32A, 32B on both sides connected to the terminal links 31A, 31B and the intermediate links 32A, 32B on both sides are arranged between the intermediate links 32A, 32B on both sides. The middle intermediate link 32 </ b> C connected to each is embedded.

  Moreover, a part of one set of links 30 among several links 30 is restrained by the relaxation | loosening state by welding. Specifically, the intermediate links 32A and 32B on both sides are welded to each other. At this time, the intermediate links 32A and 32B on both sides are welded at the closest positions, and the welded portion 4 by this welding is disposed at the center position of the middle intermediate link 32C.

  In the above-described welding, the welding amount (strength) and the welding position are adjusted in accordance with the displacement amount that applies the displacement restriction. Specifically, it is preferable to perform welding so as to be fixed at a strength corresponding to the design seismic force Hs used in the design of the displacement limiting structure defined in the road bridge specification described by the following equation.

  In addition, the design seismic force Hs used for the design of the above displacement limiting structure is smaller than the design seismic force Hf used for the design of the falling bridge prevention structure expressed by the following equation.

  Specifically, the relationship between the design seismic force Hs of the displacement limiting structure and the design seismic force Hf of the falling bridge prevention structure is approximately as follows.

  On the other hand, the rubber body 2 has a shape curved along the chain 3 and is made of a rubber material having excellent weather resistance. The rubber body 2 is filled in the gaps between the links 30 constituting the chain 3 and is covered around the links 30.

  Next, the operation of the fallen bridge prevention connector 1 shown in FIG. 1 interposed between the bridge pier 8 and the bridge girder 9 will be described. FIG. 3 is a load-displacement curve showing the relationship between the load acting on the fallen bridge prevention connector 1 and the relative displacement between the pier 8 and the bridge girder 9.

  When a small shaking occurs due to a temperature change, a live load, a small earthquake, or the like, the both ends of the falling bridge prevention connector 1 are deformed following the small displacement of the bridge girder 9. For example, when the bridge girder 9 is displaced in the direction of the bridge axis, the terminal links 31A and 31B on both sides swing in the direction of the bridge axis, so that both ends of the substantially U-shaped falling bridge prevention connector 1 are expanded or closed. Transforms into On the other hand, when the bridge girder 9 is displaced in the direction perpendicular to the bridge axis, the terminal links 31A and 31B on both sides are swung in the direction perpendicular to the bridge axis, so that both ends of the falling bridge prevention connector 1 are deformed.

In addition, in the fallen bridge preventing connector 1 having the above-described configuration, the intermediate links 32A and 32B on both sides are restrained in a relaxed state by welding, and the intermediate portion of the chain 3 is restrained. For this reason, in the case of small shaking, the welded portion 4 resists the displacement of the bridge girder 9, the deformation of the intermediate portion of the falling bridge prevention connector 1 is restricted, and the displacement of the bridge girder 9 is limited. That is, as shown in FIG. 3, the load of the displacement limiting structure is borne by the welded portion 4.
Moreover, in the case of a small-scale displacement, the buffer function by the bending deformation of the rubber body 2 acts.

On the other hand, when a large shake occurs due to a large earthquake or the like, a large load is applied to the welded portion 4. And if the load exceeding the intensity | strength of the welding part 4 is applied, the welding part 4 will be fractured | ruptured and the restraint of the chain 3 intermediate part will be cancelled | released. As a result, the entire falling bridge preventing connector 1 is deformed following the large displacement of the bridge girder 9. At this time, if the bridge girder 9 moves greatly in a direction away from the pier 8, the chain 3 is pulled and a tensile resistance force acts. Thereby, the displacement of the bridge girder 9 is regulated. That is, as shown in FIG. 3, when a load greater than the design seismic force Hs used for the design of the displacement limiting structure is applied to the welded portion 4, the welded portion 4 is pulled and broken, and when the predetermined amount of movement is reached, the fall prevention function Works.
Further, in the case of a large-scale displacement, a buffer function acts due to the bending deformation of the rubber body 2 and the tensile resistance / compression resistance of the rubber body 2 between the links 30.

According to the falling bridge prevention connector 1 having the above-described configuration, first, the displacement of the bridge girder 9 is limited by the welded portion 4, and after the welded portion 4 is broken, the displacement of the bridge girder 9 is caused by the tensile strength of the chain 3. It is regulated and the bridge girder 9 can be prevented from falling from the pier 8. In other words, the drop-bridge preventing connector 1 can exhibit not only a function of preventing a drop-bridge by the chain 3 but also a displacement limiting function by the welded portion 4. Thereby, it is not necessary to separately install a displacement limiting structure, the number of mounting steps can be reduced, and the construction can be simplified.
Moreover, the fall bridge prevention connector 1 exhibits a buffering function by the rubber body 2, and can reduce an impact when the fall bridge is prevented.

  In addition, in the above-described fallen bridge prevention connector 1, the intermediate links 32A and 32B on both sides are restrained in a relaxed state by welding. Therefore, by adjusting the area of the welded portion 4, the strength of the welded portion 4 is appropriately adjusted. Adjusted. Therefore, it is possible to adjust the amount of displacement for applying the displacement limit only by adjusting the welding amount.

  Furthermore, in the above-described bridge-bridge prevention connector 1, the welded portion 4, which is a displacement limiting structure, is embedded in the rubber body 2, so that the bridge-bridge prevention connector 1 or the bridge-bridge prevention connector 1 is attached. The brackets 10 and 12 and the pins 11 and 13 do not increase in size. Moreover, since the welding part 4 which is a displacement restriction | limiting structure is the structure which cannot be seen from the outside, the coupler 1 for a fall bridge prevention becomes a simple external appearance. Therefore, the landscape of the bridge to which the falling bridge prevention connector 1 is attached can be improved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, about the structure similar to 1st Embodiment mentioned above, the description is abbreviate | omitted by attaching | subjecting the same code | symbol.
FIG. 4 is a side view of the fallen bridge prevention connector 101 according to the present embodiment, FIG. 5 is a plan view of the fallen bridge prevention connector 101 according to the present embodiment, and FIG. 6 is a fall bridge prevention according to the present embodiment. It is a perspective view showing the internal structure of the connector 101 for an object.

  As shown in FIG. 4 to FIG. 6, the falling bridge prevention connecting device 101 in the present embodiment has a configuration in which the links 30 are restrained in a relaxed state via a connecting member 104. The connecting member 104 is a concave metal plate and is embedded in the rubber body 2. Every other link 30 is constrained via the connecting member 104. Specifically, between one terminal link 31A and the middle intermediate link 32C, between the middle middle link 32C and the other middle link 32B, and between one middle link 32A and the other middle link 32B. In between, the connection member 104 is interposed, respectively.

  More specifically, the connecting member 104A interposed between one terminal link 31A and the middle intermediate link 32C has one hooking portion 104a at the chain center side of the one terminal link 31A (FIG. 4). The other latching portion 104b is latched to one end (left side in FIG. 4) of the middle intermediate link 32C. The connecting member 104A is disposed along the lower surface (the lower side surface in FIG. 4) of one intermediate link 32A.

  In addition, the connecting member 104B interposed between the middle intermediate link 32C and the other terminal link 31B has one hooking portion 104a at the end on the other side (right side in FIG. 4) of the middle intermediate link 32C. The other hook 104b is hooked to the end of the other terminal link 31B on the chain center side (lower side in FIG. 4). The connecting member 104B is disposed along the lower surface (lower side surface in FIG. 4) of the other intermediate link 32B.

  In addition, the connecting member 104C interposed between the one intermediate link 32A and the other intermediate link 32B has one hooking portion 104a at the chain center side of the one intermediate link 32A (lower right in FIG. 4). The other hook 104b is hooked to the end of the other middle link 32B on the chain center side (lower left side in FIG. 4). The connecting member 104C is disposed along the side surface (lower side surface in FIG. 5) of the middle intermediate link 32C.

  The plurality of connecting members 104A, 104B, and 104C described above are alternately arranged. More specifically, the connecting members 104A and 104C on both sides are hung from the back side (upper side in FIG. 5) of the middle intermediate link 32C, whereas the middle connecting member 104B is on the front side of the intermediate link 32C ( It is arranged on the lower side in FIG. Further, the connecting members 104A and 104C on both sides are arranged below the intermediate links 32A and 32B on both sides (lower side in FIG. 4), whereas the middle connecting member 104B is the end of the intermediate links 32A and 32B on both sides. It is hung from the upper side of the part (upper side in FIG. 4).

  Next, the operation of the falling bridge prevention connector 101 having the above-described configuration will be described.

  When a small shaking occurs due to a temperature change or the like, the falling bridge prevention connector 101 is deformed following the small displacement of the bridge girder 9. At this time, every other link 30 is restrained by the coupling member 104 in a relaxed state and the chain 3 is restrained in the above-described structure 101 for preventing the falling bridge, so that the link 3 is connected to the displacement of the bridge girder 9. The member 104 resists, the deformation amount of the fallen bridge prevention connector 101 is limited, and the displacement of the bridge girder 9 is limited.

  On the other hand, when a large shake occurs due to a large earthquake or the like and a load exceeding the strength is applied to the connecting member 104, the connecting member 104 is broken and the restriction of the chain 3 is released. As a result, the falling bridge prevention connector 101 is greatly deformed following the large displacement of the bridge girder 9. At this time, if the bridge girder 9 moves greatly in a direction away from the pier 8, the chain 3 is pulled and a tensile resistance force acts. Thereby, the displacement of the bridge girder 9 is regulated.

  According to the fallen bridge prevention connector 101 having the above-described configuration, the fallen bridge prevention function 1 as well as the fallen bridge prevention function 1 in the first embodiment described above, the displacement limit is limited by the connection member 104. Function can be demonstrated. And since welding is unnecessary, it is hard to produce a construction defect and the displacement restriction | limiting function can be exhibited reliably. Further, since the strength of the connecting member 104 is determined by the material and shape, the amount of displacement for applying the displacement restriction can be adjusted only by selecting the shape and material of the connecting member 104.

As described above, the first and second embodiments of the coupler for preventing a fallen bridge according to the present invention have been described. However, the present invention is not limited to the above-described embodiments, and may be appropriately selected within the scope of the present invention. It can be changed.
For example, in the first embodiment described above, the links 30 are restrained in a relaxed state by welding. However, in the present invention, the links may be restrained by other methods. For example, the links may be screwed together. It can also be restrained by a stop.

  In the second embodiment described above, both ends of the connecting member 104 are hooked to the link 30, respectively. However, the end of the connecting member can be welded to the link, or It is also possible to screw the end of the connecting member to the link.

  In the second embodiment described above, the connecting member 104 made of a concave metal plate is used. However, the shape and material of the connecting member can be changed as appropriate, and a rod-like connecting member is used. It is also possible to use a resin-made connecting member.

In the first embodiment described above, the intermediate links 32A and 32B on both sides are constrained by welding, and in the second embodiment described above, the intermediate links 32A and 32B on both sides are in the middle. The intermediate link 32C and the one terminal link 31A, and the middle intermediate link 32C and the other terminal link 31B are respectively restrained via the connecting member 104. However, the present invention provides at least one pair of links. As long as the link is constrained, the combination of links constrained by welding, a connecting member, or the like can be appropriately changed. For example, the terminal links 31A, 31B and the intermediate links 32A, 32B on both sides may be constrained, or the terminal links 31A, 31B and the middle intermediate link 32C may be constrained, and the intermediate links 32A, 32B and the middle intermediate link 32C may be constrained, and further, combinations of all the links 30 described above may be constrained.
Furthermore, the present invention can also combine restraint by welding and restraint via a connecting member. That is, a configuration in which some links are constrained by welding and other links are constrained via a connecting member.

  In the first and second embodiments described above, the drop-bridge preventing couplers 1 and 101 that connect the bridge pier 8 and the bridge girder 9 with a movable support (not shown) interposed therebetween are described. The bridge prevention joints 1 and 101 are configured to allow a small displacement of the bridge girder 9. However, the bridge prevention pipe according to the present invention allows the bridge pier and the bridge girder having a fixed support interposed therebetween. It is also possible to connect them, and it may be a falling bridge preventing connecting device configured to restrict small displacement of the bridge girder. More specifically, by restraining the links so that both ends of the chain are not relatively displaced, the link for preventing a falling bridge is not deformed, and a small displacement of the bridge girder is restricted. For example, the terminal links 31A and 31B on both sides and the middle intermediate link 32C are fixed by welding. Alternatively, the terminal links 31A and 31B on both ends, the intermediate links 32A and 32B on both sides, and the intermediate links 32A and 32B on both sides are fixed by welding.

  Further, in the first and second embodiments described above, the drop-bridge preventing couplers 1 and 101 are generally curved in a substantially U shape. The shape of can be changed as appropriate. For example, it may be a fallen bridge preventing connector such as an I shape, a substantially V shape, an arc shape, or a U shape.

  Moreover, in the first and second embodiments described above, the bridge pier 8 and the bridge girder 9 are connected by the drop-bridge preventing couplers 1 and 101. However, the bridge girder is connected to each other by the drop-bridge preventing coupler according to the present invention. It is also possible to connect.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

It is a side view of the coupler for preventing a fallen bridge for explaining the first embodiment of the present invention. It is a perspective view showing the internal structure of the coupler for fallen bridge prevention for demonstrating the 1st Embodiment of this invention. It is a graph showing the load-displacement curve of the coupler for fallen bridge prevention for demonstrating the 1st Embodiment of this invention. It is a side view of the coupler for fallen bridge prevention for demonstrating the 2nd Embodiment of this invention. It is a top view of the coupler for fallen bridge prevention for demonstrating the 2nd Embodiment of this invention. It is a perspective view showing the internal structure of the coupler for fallen bridge prevention for demonstrating the 2nd Embodiment of this invention.

Explanation of symbols

1, 101 Falling bridge prevention connector 2 Rubber body (elastic body)
3 Chain 4 Welded part 8 Bridge pier (object to be connected)
9 Bridge girder (consolidated object)
30 link 104 connecting member

Claims (2)

Consists of a configuration in which the middle part of the relaxed chain is embedded in the elastic body,
In both ends of the chain attached to each connection object is interposed between the connection objects, in the fall prevention bridge connecting tool connecting the connection objects,
At least one set of links among the plurality of links constituting the chain is restrained in the relaxed state ,
A link for preventing a falling bridge, wherein the links are restrained by welding . The fallen bridge prevention connector according to claim 1 ,
The link for preventing a falling bridge, wherein the links are constrained via a connecting member provided between the links in the elastic body.

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