JP5638981B2 - Fall-bridge prevention device and fall-bridge prevention structure - Google Patents

Description

  The present invention relates to a fall-off prevention structure and a fall-off prevention apparatus that prevent a bridge girder from falling from an abutment or a pier due to an earthquake or the like, and specifically, in a chain structure used for the fall-off prevention structure and the fall-off prevention apparatus. Further, the present invention relates to a falling bridge prevention structure and a falling bridge prevention device to which a shock absorber made of an elastic body is attached.

  It has been regarded as a problem for some time that the bridge girder has fallen from the structure that supports the bridge girder such as the abutment and the pier (hereinafter referred to as “supporting frame”). More than ever before, the countermeasures against this fallen bridge have attracted attention. The term “falling bridge” is widely used for various damage phenomena in bridges. In this document, for the sake of convenience, the term “falling bridge” means that a bridge girder falls from a support frame.

  As a measure to prevent the falling bridge, there is a sufficient length of girders. Girder is the part where the bridge girder rests on the support frame, and the length of this part (the wrap length between the bridge girder and the support frame) is called the girder length. The longer the girder length is, the more difficult it is for the bridge girder to fall from the support frame, but the cost for construction increases accordingly. Therefore, in the “Road Bridge Specification / Description (Japan Road Association)” (hereinafter referred to as “Road Bridge Specification”), the minimum value of girder length is “0.7 + 0.005 × span length (m)”. It prescribes.

  However, the calculation standard for the girder length in this road bridge specification is stipulated in consideration of past earthquake magnitudes, and is not guaranteed against earthquakes of a magnitude that cannot be assumed from past experience. Therefore, in the road bridge specifications, in addition to the girder length, a displacement limiting device that limits the displacement of the bridge girder and a fall prevention device that prevents the fall bridge directly (structurally) will be installed. Stipulates to provide a double provision for

  The falling bridge prevention device connects the bridge girder that is going to move by receiving external force in the event of an earthquake by installing a connecting material such as a chain or wire rope in advance between the bridge girder and the abutment. Device. For this reason, connecting materials such as chains and wire ropes are required to have tension that can withstand a load during an earthquake. However, the load acting on this connecting material during an earthquake is not limited to a static tensile force, but includes an impact force that acts instantaneously. Accompanied by. This is because the impact force is unlikely to be compared with a static external force, and it is difficult to analyze when designing materials and the like.

  If an impact force greater than expected acts on the connecting material, for example, the ring constituting the chain breaks beyond the plastic region, i.e., the chain is cut, and as a result, the falling bridge prevention device can serve the purpose of preventing the falling bridge. become unable.

  Therefore, Patent Document 1 proposes a fall-bridge prevention structure in which a buffer material is added to the ring to form a chain, a certain amount of impact force is absorbed by this buffer material, and the remaining energy is received by the ring. .

Japanese Patent Laid-Open No. 9-242019

  The fallen bridge prevention structure shown in Patent Document 1 is a structure in which a plurality of connecting rings are arranged in a straight line and arranged in a mold, and an unsolidified raw material is poured to solidify an elastic body. That is, in the completed form, for example, a cylindrical elastic body corresponding to the shape of the mold is formed. Note that a gap is provided between the ring embedded in the cushioning material. As a result, when an impact force is received during an earthquake, the shock absorbing material (elastic body) first bears the impact force, and after this breaks, the ring is pulled and the rings are brought into contact with each other, and the ring bears the load only after the chain is pulled. It has a structure to do.

  However, the falling bridge prevention structure shown in Patent Document 1 has some problems. In other words, the cushioning material is molded by pouring unsolidified raw material into the mold (especially if the elastic body is rubber, the vulcanization process is also performed), so that it is not at the site of enforcement such as a factory or yard (site of prevention of falling bridges) It will be created in the place of. For this reason, there is a problem that not only a predetermined space and facilities are required, but also it takes a relatively long time to mold the elastic body.

  In addition, the cushioning material has a columnar shape or a rod shape such as a cylindrical shape or a prismatic shape according to the shape of the mold, and since a relatively large amount of material is used, the material cost increases and the weight is moderate, so it is difficult to transport and install. I had the problem of being.

  Furthermore, by providing a gap between the rings embedded in the cushioning material, it is possible to bear the impact force in the order of the cushioning material to the ring, but after forming the cushioning material, between the rings It is impossible to visually confirm whether or not the gap is properly provided. In other words, there was a problem that it was difficult to confirm and inspect the product.

  An object of the present invention is to provide a falling bridge prevention structure and a falling bridge prevention device that solve the above-described problems.

The falling bridge prevention device of the present invention is a falling bridge prevention device capable of preventing a bridge girder from falling from a support frame that supports the bridge girder, wherein a plurality of rings are connected to both ends of the chain member by a ring coupling portion. And a part or all of the chain member is a buffer chain member having a buffer, and the buffer is made of an elastic body and is disposed between adjacent rings in the ring connecting portion . The connection jig connected to one end side of the chain member can be coupled to a support-side fixture installed on a support housing, and the connection jig connected to the other end side of the chain member is connected to a bridge girder. Ri coupleable der in the installed digit side fixture, a hollow cylindrical protective tube is provided on at least the outer periphery of the buffer chain members of the chain member, fixed to at least the axial direction two or more locations of the protective tube By passing through the inside of the ring of the buffer chain member in the protective tube and connecting the protective tube and the buffer chain member with the stopper, the ring between the rings of the buffer chain member is prevented, and the ring It is possible to prevent the shock absorber from dropping out, and to prevent the protective tube from falling off the shock absorbing chain member .

The fallen bridge prevention device of the present invention may be configured such that in the fallen bridge prevention device, the stopper is penetrated at least at both axial ends of the protective tube . A cap material is provided on both ends or one end side in the axial direction of the protective tube and outside the buffer chain member, and the cap material is attached to the protective tube with a stopper, and is attached to both ends or one end side in the axial direction of the protective tube. The opening may be closed with the cap material.

The fallen bridge prevention device of the present invention is the fallen bridge prevention device, wherein the stopper for attaching the cap material to the protective tube and the stopper for connecting the protective tube and the buffer chain member are combined, and the stopper is the protective tube and the inside thereof. The protective tube, the cap material, and the ring are connected by penetrating through the ring of the cap material and the buffer chain member .

The fallen bridge prevention device of the present invention may be provided with a recessed part that allows the cap material to be placed on the outer side of the rod member of the ring of the buffer chain member in the protective tube in the fallen bridge prevention device . The cap material may be divided into two or more so that it can be individually installed in the protective tube, and each cap material may be provided with a recessed portion that can be put on the outside of the rod member of the ring of the buffer chain member. . A fitting groove into which a part of the ring of the cushioning chain member disposed on the outer surface of the cushioning tool can be fitted may be provided.

The falling bridge prevention structure of the present invention is a falling bridge prevention structure that can prevent a bridge girder from falling from a supporting frame that supports the bridge girder, a falling bridge prevention device, a support-side fixture installed in the support frame, and a bridge girder. And a bridge prevention device is any one of the above-mentioned bridge prevention devices, and a connecting jig provided on one end side of the chain member of the bridge protection device is coupled to the support side fixture . A connection jig provided on the other end side of the chain member is connected to the beam-side fixture.

The falling bridge prevention structure and the falling bridge prevention device of the present invention have the following effects.
(1) Even when a relatively large impact force is applied during an earthquake or the like, a predetermined energy can be absorbed by a shock absorber made of an elastic body, so that the ring is not burdened and is not easily broken. As a result, it is possible to prevent a fallen bridge even when the impact force is greater than that of a ring.
(2) Compared with the prior art, the amount of use of the elastic body, which is the material of the shock absorber, can be remarkably reduced, so that the economy is excellent. Moreover, since the weight is light, it is easy to carry, easy to install, and excellent in workability.
(3) The shock absorbers can be installed in advance at factories, etc., and can also be installed at the construction site (site for preventing fallen bridges). It can be used at any site.
(4) Since the mounting state of the impact tool can be visually confirmed very easily, a safe fall prevention device can be provided reliably, and construction inspection of the fall prevention structure can be performed accurately.
(5) If a protective tube is installed on the outer periphery of the buffer chain member, the buffer device can be protected from a sudden temperature change, intense sunlight, etc., and therefore the deterioration of the buffer device can be prevented over a long period of time.
(6) If a fitting groove in which a part of the ring is fitted is provided on the surface of the shock absorber, the shock absorber once attached is not easily removed even in an unexpected situation, and a more reliable fall prevention structure and a fall prevention device are provided. It becomes.

The whole figure which looked at the bridge to which the fallen bridge prevention structure of the invention of this application was attached from the side. The partial side view which shows the detail of the fall-bridge prevention structure of this invention. The detailed drawing which cut virtually a part of the fall bridge prevention device of the present invention. (A) is a detailed view for explaining details of mounting a shock absorber between adjacent rings, (b) is a cross-sectional view taken along the line XX of (a), and (c) is a fitting groove on the surface of the cylindrical body. FIG. 4D is a detailed view showing a shock absorber provided with a fitting, and FIG. 4D is a detailed view showing the shock absorber provided with a fitting groove on the surface of a sphere. (A) is a perspective view explaining a cap material, (b) is a sectional view of the cap material attached to a protective tube, (c) is a perspective view explaining another example cap material, and (d) is another example cap. Sectional drawing which attached the material to the protective tube.

[Embodiment]
One embodiment of a fall-bridge prevention structure and fall-bridge prevention apparatus of the present invention will be described with reference to the drawings. FIG. 1 is an overall view of a bridge to which a falling bridge prevention structure of the present invention is attached as viewed from the side, FIG. 2 is a partial side view showing details of the falling bridge prevention structure of the present invention, and FIG. It is the detail drawing which cut a part virtually.

(overall structure)
The bridge shown in FIG. 1 is a three-span bridge composed of three bridge girders 2, and each bridge girder 2 is supported by an abutment 3 and a pier 4. The falling bridge prevention device 1 is installed at a place where the abutment 3 supports the bridge girder 2 (left side in the figure), and connects the abutment 3 and the bridge girder 2. In addition, as shown in the figure, the falling bridge prevention device 1 can be installed to connect the bridge girder 2 and the bridge pier 4 or to connect the bridge girder 2 and the bridge girder 2 to each other. Moreover, in order to connect the bridge girder 2 with the other structure which can support the bridge girder 2, the falling bridge prevention apparatus 1 can also be installed. Of course, the falling bridge prevention device 1 of the present invention can be installed not only on the three-span bridge shown in FIG. 1 but also on any type of bridge. It can be applied to various girders such as factory girders such as PC girders. Of course, the fall prevention device 1 can be installed on a new bridge, or the fall prevention device 1 can be attached to an existing bridge.

  As described above, the falling bridge prevention device 1 can be attached to a frame (hereinafter referred to as “supporting frame”) that can support the bridge girder 2 such as an abutment 3, a pier 4, and other structures. The case where the support frame is attached to the abutment 3 will be described. Furthermore, as described above, the falling bridge prevention device 1 is not limited to the bridge girder 2 and the abutment 3, but can be installed to connect the bridge girder 2 and other supporting frame, the bridge girder 2 and the bridge girder 2, or in a cross section perpendicular to the bridge axis. Although it can be installed at one place or two or more places, in the present embodiment, for convenience, description will be made on the case where the bridge girder 2 and the abutment 3 are connected and installed at one place in a cross section perpendicular to the bridge axis.

  As shown in FIG. 2, the bridge girder 2 is placed on a support 5 installed on the abutment 3, and is connected to the abutment 3 by the falling bridge prevention device 1. The falling bridge prevention device 1 includes a chain member 101 and connecting jigs provided at both ends of the chain member 101. One of the connection jigs is connected to a girder-side fixture 6 installed on the bridge girder 2, and the other of the connection jigs is connected to a support-side fixture 7 installed on the abutment 3. Here, for the sake of convenience, the connecting jig connected to the bridge girder 2 at the end of the chain member 101 is referred to as the girder side connecting jig 102a, and the connecting jig connected to the abutment 3 is referred to as the support side connecting jig 102b. . That is, the girder-side connecting jig 102 a and the girder-side fixture 6 are connected, and the support-side connecting jig 102 b and the support-side fixing tool 7 are connected, so that the falling bridge prevention device 1 is placed between the bridge girder 2 and the abutment 3. Installed.

  The chain member 101 is formed by connecting a large number of rings 103, and includes a buffer chain member 101a and a general chain member 101b. As will be described later, the buffer chain member 101a is provided with a shock absorber 8 (FIG. 3) made of an elastic body between the ring 103 and the ring 103 to be connected. For example, the chain member 101 is tensioned by an impact force during an earthquake. Then, the shock absorber 8 sandwiched between the rings 103 can absorb a part of the energy of the impact force. On the other hand, the general chain member 101b is a chain member to which the shock absorber 8 is not attached and is a normal chain 103 connection. In FIG. 2, the chain member 101 is composed of the buffer chain member 101a and the general chain member 101b. However, the chain member 101 can be entirely composed of the buffer chain member 101a.

  As shown in FIG. 2, a protection tube 104 can be installed on the buffer chain member 101a. The shock absorber 8 is made of, for example, chloroprene rubber, and may be deteriorated by the influence of heat from sunlight, ultraviolet rays, heat from a firearm, etc., long-term wind and rain, and the like. Therefore, the protection tube 104 can be installed on the buffer chain member 101a to protect the buffer 8. It should be noted that the installation of the protective tube 104 is not essential for the fallen bridge prevention device 1 of the present invention, and can be omitted, and it is desirable to design whether or not the protective tube 104 can be installed in consideration of the use environment, the use period, and the like. .

  The girder-side fixture 6 is a so-called bracket type in which steel plates or the like are combined, and is fixed to the bridge girder 2 using a conventional method such as bolt fixing or welding fixing. Similarly, the support-side fixture 7 is also a bracket type that combines steel plates or the like, and is fixed to the abutment 3 using a conventional method such as bolt fixing. Of course, the girder-side fixture 6 and the support-side fixture 7 are not limited to those of the bracket type, and can be fixed to the bridge girder 2 or the abutment 3, and the connection jig (girder side connection jig 102a) of the chain member 101 can be used. As long as it can be connected to the support-side connecting jig 102b), various types conventionally used can be adopted.

  In FIG. 2, the falling bridge prevention device 1 is bent (provided with a sag) between the bridge girder 2 and the abutment 3. By providing this sag, a slight displacement of the bridge girder 2 is allowed until the function of the falling bridge prevention device 1 is exhibited. As described above, the fallen bridge prevention device 1 can be installed with a sag. However, the fallen bridge prevention device 1 can be provided with tension (that is, in a straight line) from the beginning, and can quickly exhibit the function of the fallover prevention device 1. It is desirable to design the sag amount (or presence / absence) of the falling bridge prevention device 1 according to the amount of displacement of the bridge girder 2 that is allowed in design.

  Hereinafter, each component will be described in detail.

(Chain member)
As described above, the chain member 101 is formed by connecting a large number of rings 103. As shown in FIG. 3, the ring 103 is connected by being inserted into a ring of the adjacent ring 103, and the chain member 101 is configured by repeating this many times. Since each ring 103 is inserted into the ring of the adjacent ring 103, when a tensile force (force applied in the left-right direction in FIG. 2) acts on the chain member 101, a part of the ring 103 is adjacent to the ring 103. Contact with some of the. The chain member 101 is tensioned by transmitting a force at a connecting portion between the rings 103 (hereinafter referred to as “ring connecting portion”).

  The dimensions and standards of the ring 103 used for the chain member 101 are selected according to the allowable load (the load at which the chain member 101 breaks). For example, assuming that the load acting during an earthquake is 825 kN, it is possible to select a ring 103 having a ring diameter of 38 mm, an inner space (oval size of a ring in the ring) of 57 mm × 266 mm, and a material standard of SCM435H. . The surface of the ring 103 is preferably subjected to rust prevention processing such as hot dip galvanization.

  As shown in FIG. 2, the chain member 101 includes a buffer chain member 101 a and a general chain member 101 b, which are connected by a shackle 9. In addition, the size of the ring 103 constituting the buffer chain member 101a, the chain length, etc. (hereinafter referred to as “chain dimension”) are determined by the size and shape of the shock absorber 8, while the general chain The chain dimension of the member 101b has one aspect that is determined by the total installation length of the chain member 101. Therefore, the chain dimensions of the buffer chain member 101a and the general chain member 101b may be the same or different. Of course, not only the shackle 9 but also the ring 103 can be used to connect the buffer chain member 101a and the general chain member 101b.

(Buffer chain member)
As shown in FIG. 3, the buffer 8 is attached to the buffer chain member 101a. FIG. 4A is a detailed diagram illustrating details of mounting the shock absorber 8 between adjacent rings 103. As shown in this figure, a gap (hereinafter referred to as “gap portion”) is provided between one ring 103 and the other ring 103 in the connecting portion 103 a to which the adjacent rings 103 are connected. A shock absorber 8 made of an elastic body is attached to the gap.

  By providing a gap between adjacent rings 103 and providing the buffer 8 in this gap, when a tension force acts on the chain member 101, the buffer 8 becomes a buffer and a part of energy ( Absorb the whole). This point will be specifically described by taking the case of an earthquake as an example. When an earthquake occurs, an instantaneous dynamic load (impact force) acts, and the bridge girder 2 moves in the direction of falling from the abutment 3 (rightward in FIG. 2) due to the horizontal component of the impact force. As the movement of the bridge girder 2 proceeds, the chain member 101 of the falling bridge prevention device 1 is pulled into a linear shape, and when further pulled, the chain member 101 tends to extend. At this time, a force acts in the connecting portion 103a in a direction in which both adjacent rings 103 are in contact with each other. On the other hand, a gap portion is provided in the connecting portion 103a between the rings 103, and the shock absorber 8 is attached to the gap portion. Therefore, in this state, the adjacent rings 103 are still indirectly connected to each other. That is, the shock absorber 8 sandwiched between both the rings 103 receives a compressive force. When this compressive force further increases, the shock absorber 8 made of an elastic body may be broken due to deformation in the elastic region (from the elastic region to the plastic region, and eventually break. In this case, the shock absorber 8 breaks. Part of the impact force due to the earthquake is reduced, and the remaining impact force acts on the chain member 101 and resists it by the strength of the ring 103.

  Thus, the shock absorber 8 functions by receiving a load from the ring 103, and is preferably installed in contact with the ring 103. For example, as shown in FIG. 4A, the shock absorber 8 may be inserted and mounted so as to fill a gap provided in the connecting portion 103a. FIG. 4B is a diagram illustrating a close contact state between the shock absorber 8 and the ring 103, and is a cross-sectional view taken along the line XX in FIG. As can be seen from FIG. 4 (b), in the gap where the adjacent rings 103 intersect, four rod members 103 b forming the ring 103 (one two and the other two) contact the shock absorber 8. ing.

  A fitting groove 8 a (FIG. 4C) can also be provided on the surface of the shock absorber 8 so that the shock absorber 8 is in reliable contact with the ring 103. The fitting groove 8 a has a shape such that a part of the rod member 103 b forming the ring 103 is just fitted. Also in the cross-sectional view of FIG. 4B, a part of the four rod members 103b are respectively fitted in the fitting grooves 8a. The cushioning tool 8 shown in FIG. 4C has a shape including two fitting grooves 8a cut out in an elliptical shape on the surface of the cylindrical body. As shown in d), the shape can be any shape such as a shape in which the fitting groove 8a is provided on the surface of the sphere, a prismatic shape, a polyhedral shape, etc., and the fitting groove 8a can be omitted. it can.

  The shock absorber 8 can be made of rubber of various materials such as chloroprene rubber, and other elastic materials including various resins can be selected. Further, the shock absorber 8 can be manufactured in advance at a factory or the like and mounted at the site (installation site of the fallen bridge prevention device 1). Depending on the local situation, the buffer 8 is not solidified in the gap portion of the connecting portion 103a. The material can be poured and solidified, that is, the shock absorber 8 can be manufactured and installed on site. In order to prevent the shock absorber 8 from falling off, the shock absorber 8 is fixed to the ring 103 or adhered by keeping the length of the shock absorber chain member 101a constant (that is, suppressing expansion and contraction due to loosening) as described later. It is desirable to bond the shock absorber 8 to the ring 103 using an agent or the like, attach the shock absorber 8 to the ring 103 with a tape or the like, or fix the shock absorber 8 using various means.

(Protection tube)
The protection tube 104 protects the shock absorber 8 from deterioration due to the influence of heat from sunlight, ultraviolet rays, heat from firearms, and long-term wind and rain, and is installed to protect the outer periphery of the buffer chain member 101a. The As shown in FIG. 3, the protective tube 104 has a hollow columnar shape (cylindrical shape). Of course, the shape is not limited to a cylindrical shape, and an arbitrary shape such as a hollow prism shape can be selected. However, a hollow shape that can cover the entire outer periphery of the buffer chain member 101a is desirable. The reason why the hollow is desirable is to reduce the material cost and facilitate the construction by reducing the weight. Further, by installing the protective tube 104, there is an effect that the shape (posture) of the buffer chain member 101a in the tube can be maintained and the buffer 8 can be prevented from falling off.

  The protective tube 104 is preferably made of a relatively hard material in terms of maintaining the posture of the buffer chain member 101a, and STK400 is preferably used in consideration of weather resistance and the like. Of course, the present invention is not limited to this, and other materials can be used, and a bellows type made of FRP can be used for the purpose of following the deformation of the buffer chain member 101a. In addition, when using STK400 etc. for the protective tube 104, it is desirable to give antirust processing, such as hot dip galvanization.

  As a method of installing the protective tube 104 on the buffer chain member 101a, a method of fixing the protective tube 104 by sewing it with a bolt and penetrating it into the ring 103, or an annealing iron wire (numbered wire) between the protective tube 104 and the ring 103 is used. Various methods conventionally used, such as a method for tying them together, can be adopted. In this case, a cap material 104a shown in FIG. 5A can also be used. 5A is a perspective view illustrating the cap material 104a, FIG. 5B is a cross-sectional view of the cap material 104a attached to the protective tube 104, and FIG. 5C illustrates another example of the cap material 104a. FIG. 5D is a cross-sectional view in which another example cap member 104a is attached to the protective tube 104. FIG.

  The cap material 104a is attached by being fitted to both ends (or only one end) of the protective tube 104. Considering that the cap material 104a is attached after the buffer chain member 101a is inserted into the protective tube 104, FIG. Further, it is desirable to be divided as shown in FIG. The cap material 104a is provided with a through hole through which the rod member 103b of the ring 103 can pass. In FIG. 5B, one set (two) of the through holes is provided. However, as shown in FIG. 5D, two sets of through holes (four) may be provided. The cap material 104a is preferably an elastic body that can be easily deformed, such as rubber or resin. The number of divisions of the cap material 104a is not limited to two, and can be three or more.

  Depending on the cross-sectional area of the cap material 104 a and the cross-sectional area of the protective tube 104, the protective tube 104 can be fixed simply by fitting the cap material 104 a to the end surface of the protective tube 104. Alternatively, as shown in FIG. 5B and FIG. 5D, after the cap material 104a is fitted to the end surface of the protective tube 104, the cap material 104a and the protective tube 104 are sewn with the bolt 104b to ensure more certainty. It is also possible to fix the protective tube 104. In this case, if the cap member 104a is tightened with the bolt 104b at both ends of the protective tube 104, the length of the buffer chain member 101a can be kept constant, so that the above-mentioned "drop off of the buffer 8" can be prevented. The effect that it can be produced. To illustrate the procedure for fixing the protective tube 104, the buffer chain member 101 a is inserted into the protective tube 104, and a split piece of the cap material 104 a is attached to the end surface of the protective tube 104. At this time, the cap member 104a is attached while the rod member 103b is inserted into the through hole, and then the remaining pieces of the cap member 104a are similarly attached. The cap material 104a is also attached to the end face of the other protective tube 104, and the cap material 104a attached to both ends is sewn to the protective tube 104 with bolts 104b. The bolt 104b may be one that penetrates the protective tube 104 as shown in FIG. 5B, or may be a plurality of bolts that do not penetrate as shown in FIG. 5D (four in the figure). Further, the cap material 104a can be provided with a through hole for the bolt 104b in advance (FIG. 5A), or can be directly sewed with the bolt 104b without providing a hole for the bolt 104b. In any case, it is desirable to provide a hole for the bolt 104b in the protective tube 104 in advance. Sealing the attached cap material 104a is preferable because it can prevent intrusion of rainwater or the like.

(Connection jig)
The connecting jig is a part of the falling bridge prevention device 1 and is provided at both ends of the chain member 101 and connected to the girder-side fixing tool 6 is a girder-side connecting jig 102a. What is coupled to the support side connection jig 102b. As these girder side connecting jig 102a and supporting side connecting jig 102b, shackles 9 can be used as shown in FIG. Of course, the present invention is not limited to this, and various conventional jigs can be used as long as the end ring 103 of the chain member 101 can be connected to the support side fixture 7 and the girder side fixture 6. Can be used.

(Fixture)
As described above, the girder-side fixture 6 and the support-side fixture 7 are of a so-called bracket type in which steel plates or the like are combined, and are fixed to the bridge girder 2 or the abutment 3 by bolt fixing or the like. In FIG. 2, the girder-side fixture 6 is fixed to the side surface of the bridge girder 2, but the girder-side fixture 6 can also be fixed to an arbitrary place such as the bottom surface of the bridge girder 2. Similarly, in FIG. 2, the support-side fixture 7 is fixed to the wall surface on the front side of the abutment 3. However, the support-side fixture 7 is not limited to this and is fixed to any place such as the wall surface on the side surface side of the abutment 3. You can also.

[Other Embodiments]
In the above-described embodiment, the case where the falling bridge prevention device 1 is installed in the direction of the bridge axis has been described, but instead of this, or in addition, the falling bridge prevention device 1 can be installed in the direction perpendicular to the bridge axis. .

  The falling bridge prevention structure and the falling bridge prevention device of the present invention can be used for various bridges such as road bridges, railway bridges, river bridges and viaducts. Further, the present invention is not limited to the connection between a supporting girder and a bridge girder such as a bridge girder and an abutment, and can be applied by attaching between various structures such as a tunnel gate, a retaining wall, or a building structure such as a building.

DESCRIPTION OF SYMBOLS 1 Falling bridge prevention apparatus 2 Bridge girder 3 Abutment 4 Bridge pier 5 Support 6 Girder side fixing tool 7 Support side fixing tool 8 Buffering tool 8a Fitting groove 9 Shackle 101 Chain member 101a Buffer chain member 101b General chain member 102a Girder side connection jig 102b Support Side connection jig 103 Ring 103a Connecting portion 103b (between rings) Bar member 104 Protective tube 104a Cap material 104b Bolt

Claims (8)

In the falling bridge prevention device that can prevent the bridge girder from falling from the support frame that supports the bridge girder,
A chain member in which a plurality of rings are connected by a ring connecting portion, and a connection jig connected to both ends of the chain member,
A part or all of the chain member is a buffer chain member having a buffer,
The shock absorber is made of an elastic body and is disposed between adjacent rings in the ring connecting portion,
The connection jig connected to one end side of the chain member can be connected to a support-side fixture installed on a support housing, and the connection jig connected to the other end side of the chain member is installed on a bridge girder. Ri coupleable der in number of digits side fixture,
A hollow cylindrical protective tube is provided on at least the outer periphery of the buffer chain member of the chain members, and a stopper is passed through at least two locations in the axial direction of the protective tube so that the inside of the ring of the buffer chain member in the protective tube is also provided. By connecting the protective tube and the buffer chain member with the stopper, the buffer chain member can be prevented from loosening between the rings, and the buffer can be prevented from falling off between the rings. Can prevent the protective tube from falling off,
A fallen bridge prevention device characterized by that. The fallen bridge prevention device according to claim 1,
The stopper was penetrated at least at both axial ends of the protective tube,
A fallen bridge prevention device characterized by that. In the fallen bridge prevention device according to claim 1 or claim 2,
A cap material is provided on both ends or one end side in the axial direction of the protective tube and outside the buffer chain member, and the cap material is attached to the protective tube with a stopper, and is attached to both ends or one end side in the axial direction of the protective tube. The opening was closed with the cap material,
A fallen bridge prevention device characterized by that. In the fallen bridge prevention device according to claim 3,
The stopper that attaches the cap material to the protective tube is combined with the stopper that connects the protective tube and the buffer chain member, and the stopper penetrates through the ring of the protective tube, the cap material inside the buffer tube and the buffer chain member. The protective tube, the cap material and the ring are connected by
A fallen bridge prevention device characterized by that. In the fallen bridge prevention device according to claim 3 or claim 4,
The cap material has a recess that can be put on the outside of the rod member of the ring of the buffer chain member in the protective tube,
A fallen bridge prevention device characterized by that. The fallen bridge prevention device according to claim 5,
The cap material is divided into two or more so that it can be individually installed in the protective tube, and each cap material is provided with a recessed portion that can be put on the outside of the rod member of the ring of the buffer chain member.
A fallen bridge prevention device characterized by that. In the fallen bridge prevention device according to any one of claims 1 to 6 ,
A fitting groove into which a part of the ring of the cushioning chain member disposed on the outer surface of the cushioning tool can be fitted is provided.
A fallen bridge prevention device characterized by that. In the fall prevention structure that can prevent the fall of the bridge girder from the support frame that supports the bridge girder,
A falling bridge prevention device, a support-side fixture installed on the support housing, and a girder-side fixture installed on the bridge girder,
The falling bridge prevention device is the falling bridge prevention device according to any one of claims 1 to 7,
A connection jig provided on one end side of the chain member of the falling bridge prevention device is coupled to the support-side fixture, and a connection jig provided on the other end side of the chain member is coupled to the girder-side fixture. The
A fallen bridge prevention structure characterized by that.

Images