JP2017223032A - Anchorage fitting for bridge fall prevention device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anchorage fitting for a bridge fall prevention device, which has necessary strength, which dispenses with a burdensome work such as full penetration weld, and which can reduce a manufacturing cost, and a method of manufacturing the anchorage fitting.SOLUTION: An anchorage fitting 1 for a bridge fall prevention device 10 for preventing an upper structure (bridge girder H) of a bridge from falling from a lower structure (abutment B) includes a base plate 2 that is made of a thick-plate steel plate, and a top plate 3 that has a plate surface orthogonal to the base plate 2. The base plate 2 and the top plate 3 are cut out from extremely-thick H-shaped steel, the web of which is almost equal in plate thickness to a flange, and integrally molded.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fall prevention apparatus for preventing a bridge girder from dropping, and more particularly to a fixing bracket for a fall prevention apparatus that is attached and fixed to an upper structure or a lower structure of a bridge and a method for manufacturing the same.

  In general bridges, bridge upper structures such as bridge girders and bridge substructures such as abutments and piers are not rigidly joined, but they are joined by roller bearings or pin bearings via bearing members. It has become a structure. For this reason, from the viewpoint of preventing major accidents involving human lives, the bridge upper structure is connected to the bridge lower structure with a fall prevention device such as a fall prevention chain that prevents the bridge upper structure from falling from the bridge lower structure. Has been.

  2. Description of the Related Art Conventionally, as this kind of falling bridge prevention device, a buffer chain has been proposed in which links are connected by interposing a buffer material such as rubber that absorbs an impact so as not to break due to an impact load transmitted during an earthquake or the like.

  For example, in Patent Document 1, a fixing member 8 fixed to the side surface near the upper end of the pier 1, a fixing member 10 fixed to the lower surface near the end of the girder 2, and the like are arranged between them. A buffer member 5, a connection member 9 that connects one end of the buffer member 5 and the fixing member 8, and a connection member 11 that connects the other end of the buffer member 5 and the fixing member 10. A girder dropping prevention structure 101 provided so as to connect the two is disclosed (claim 1 of patent document 1, paragraphs [0017] to [0022] of the specification, FIG. 1 of the drawings, (See FIG. 2).

  Further, Patent Document 2 discloses a falling bridge prevention device in which a bracket metal member 5 fixed to an abutment or a pier 1 and a bracket metal member 6 fixed to a bridge girder 2 are coupled by a connecting member 7, and the bracket metal members 5 and 6 are combined. Is composed of a combination of a fixing base plate 12 and a bracket 13 that is fixed to the base plate 12 and has a portion to which the connecting member 7 is coupled. The fixing angle of the bracket 13 with respect to the base plate 12 can be selected. (Refer to claim 1 of claim 1 of patent document 1, paragraphs [0025] to [0036] of the specification, and FIGS. 2 and 3 of the drawings).

  The fixing members 8 and 10 of Patent Document 1 and the base plate 12 (+ hinge plate 24) of Patent Document 2 which are fixing brackets of such a fallen bridge prevention device are formed on a base plate made of a thick steel plate having a thickness of 22 mm or more. A top plate made of the same piece of material that was orthogonal to each other was produced by providing a groove at the tip and joining them together by full penetration welding. This is because when a quoting force is applied to the top plate via the connecting member 9 of Patent Document 1 or the connecting member 7 of Patent Document 2, there is a possibility that tensile stress is generated in the weld line that joins the top plate and the base plate. This is because it was necessary to perform complete penetration welding in order to resist the tensile stress.

  However, full penetration welding takes time for both groove processing and welding, and it takes time and effort, and the difficulty of welding is high. . In addition, full penetration welding depends on the skill of the welder's arm, welding defects are likely to occur, and it is difficult to inspect all of them due to cost, and the inspection method for defects is insufficient. there were.

  In addition, although it is conceivable to cast the fixing bracket of such a fallen bridge prevention device, since the casting has a large tolerance of about 5 mm to 10 mm, there is a problem that there is little play for accuracy error and the degree of freedom in mounting. . In addition, casting requires a mold, and there is a problem that the unit price increases in the production with a small lot. In particular, the fixing bracket to be attached to the lower structure changes in shape depending on the position of the hole of the anchor bolt, so that the shape is different each time, resulting in an increase in manufacturing cost.

Japanese Patent Laid-Open No. 9-242019 JP 2008-106451 A

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the object of the present invention is to have the required strength and to eliminate the need for laborious work such as complete penetration welding, thereby reducing the production cost. It is an object of the present invention to provide a fixing bracket for a falling bridge prevention device and a method for manufacturing the same.

  According to a first aspect of the present invention, there is provided a fixing bracket of the fall prevention device according to the first aspect of the present invention, wherein the fixing bracket of the fall prevention device prevents the upper structure of the bridge from falling from the lower structure. A top plate having orthogonal plate surfaces, and the base plate and the top plate are integrally formed by cutting out from an extremely thick H-shaped steel having a web thickness equal to that of the flange. It is characterized by.

  According to a second aspect of the present invention, there is provided the fixing bracket of the falling bridge prevention device according to the first aspect, wherein a bending reinforcing rib having a plate surface orthogonal to the base plate and the top plate is formed.

  According to a third aspect of the present invention, there is provided a method for manufacturing a fixing bracket of a fall prevention device according to the third aspect of the present invention, which is a manufacturing method of a fixing bracket for a fall prevention device that prevents the upper structure of a bridge from falling from the lower structure. A base plate and a top plate having a plate surface perpendicular to the base plate are cut out from an extremely thick H-shaped steel having a web thickness equal to that of the flange, and are integrally formed.

  The fallen bridge prevention member according to a fourth aspect of the invention includes the step of welding a bending reinforcement rib for resisting bending stress acting on the top plate so as to be orthogonal to the base plate and the top plate in the third aspect of the invention. Features.

  According to the first to fourth inventions, since the base plate and the top plate are cut out from an extremely thick H-section steel whose web thickness is about the same as the flange thickness, it is integrally formed. This eliminates the need for troublesome work such as welding, and can reduce the production cost. In addition, since the base plate and the top plate are made of an extremely thick H-section steel formed by continuous rolling, the ultra-thick H-section steel can be obtained when the top plate is pulled in the out-of-plane direction of the base plate as compared with full penetration welding. Since a haunch with R is formed at the corner between the flange and the web, stress is not concentrated and resistance to bending of the base plate is large, so no examination is required. .

  In particular, according to the second and fourth inventions, since the bending reinforcement rib is formed, the performance against the out-of-plane bending stress of the top plate is further enhanced, and the strength of the fixing bracket is improved.

It is a perspective view which shows the case where the fallen bridge prevention apparatus which concerns on embodiment of this invention is connected between the bridge abutment B made from concrete, and the bridge girder H which consists of H steel, and is bridged. It is a perspective view which shows the fixing metal fitting which concerns on embodiment of this invention. It is a front view which shows the fixing bracket same as the above. It is a left view which shows the fixing bracket same as the above. It is a top view which shows the fixing metal fitting same as the above. It is a perspective view which shows the cutting position of the extra-thick H-section steel at the time of cutting out the fixing metal fitting same as the above.

  Hereinafter, a fixing bracket of a fallen bridge prevention device according to an embodiment of the present invention will be described with reference to the drawings.

[Fixing bracket of the fallen bridge prevention device]
First, the fixing bracket of the falling bridge prevention device according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a falling bridge prevention device 10 according to an embodiment of the present invention. As shown in FIG. 1, the falling bridge prevention device 10 according to the embodiment of the present invention is a state in which a bridge lower structure such as an abutment or a pier and a bridge upper structure such as a bridge girder are slackened with a margin of length. To prevent the upper structure from falling from the lower structure. The illustrated form illustrates a case where a reinforced concrete abutment B is connected to a bridge girder H made of a section steel such as an H-section steel or an I-section steel.

  As shown in FIG. 1, the fallen bridge prevention device 10 according to the embodiment of the present invention mainly includes a pair of fixing brackets 1, 1 ′ according to the embodiment of the present invention and a connecting member 11 that connects them. These are connected by a shackle S which is a distribution product.

  The connecting member 11 includes a general chain 12 composed of a chain in which a plurality of ring-shaped steel materials manufactured by quenching and tempering heat treatment from chromium molybdenum steel (SCM420H or SCM430), and natural rubber around the chain. A hard rubber mixed with a synthetic rubber is composed of a buffer chain 13 and the like covered in a columnar shape, and these are connected by a shackle S that is a distribution product.

  The steel material exposed portions of the general chain 12 and the buffer chain 13 are hot dip galvanized for rust prevention.

<Fixing bracket>
As shown in FIG. 1, the fixing bracket 1 according to the present embodiment is a bracket that is fixed to an abutment B that is a lower structure of a bridge with an anchor bolt, and the fixing bracket 1 ′ is an upper structure of a bridge. A metal fitting fixed to the bridge girder H with high-strength bolts. The difference between the fixing bracket 1 and the fixing bracket 1 ′ is only the position of the bolt hole through which the bolt is inserted, and the other configurations are substantially the same. Therefore, the fixing bracket 1 fixed by the anchor bolt is illustrated as an example. explain. Anchor bolts installed on the abutment B, which is a concrete structure, are often post-installed anchors such as chemical anchors, and the position error during construction is large. For this reason, the fixing bracket 1 is often drilled with a bolt hole after measurement at the site, and the fixing bracket 1 ′ is drilled as designed.

  2 is a perspective view showing the fixing metal fitting 1 according to the present embodiment, FIG. 3 is a front view showing the fixing metal fitting 1, FIG. 4 is a left side view thereof, and FIG. 5 is a plan view thereof.

  2 to 5, the fixing bracket 1 according to the present embodiment includes a base plate 2, a top plate 3 having a plate surface orthogonal to the base plate 2, and a plate surface orthogonal to the base plate 2 and the top plate 3. It is comprised from the four reinforcement ribs 4 in total which have.

(Base plate)
The base plate 2 is a rectangular plate having a width of 230 mm and a length of 520 mm made of a thick steel plate having a thickness of 25 mm, and a total of ten bolt holes 20 through which bolts are inserted are drilled at five locations on one side. Of course, it goes without saying that the plate dimensions, the number of bolt holes 20 and the like may be appropriately set according to the structural design.

(Top plate)
The top plate 3 is a triangular plate made of a thick steel plate having a thickness of 25 mm, which is the same material as the base plate 2, and has a rounded apex and a circular shape, and a connecting hole 30 through which a shackle connected to the connecting member 11 is inserted in the center. Is drilled. In addition, a disc-like (record disc-like) ring plate 31 is mounted around the connection hole 30 in order to distribute the supporting pressure acting on the shackle pin.

  Further, the base plate 2 and the top plate 3 are cut out from an extremely thick H-shaped steel in which a flange and a web are continuously rolled by a universal molding machine and are integrally formed. In addition, in many cases, the extremely thick H-section steel refers to an H-section steel having a flange thickness of 30 mm or more. However, in this specification, the thickness of the web generally used for a building column is generally a flange plate. It refers to H-section steel of the same thickness.

  In the fixing bracket 1 according to the present embodiment, the extremely thick H-shaped steel to be cut out has a width of 500 mm, a height of 500 mm, a web thickness of 25 mm, and a flange thickness of 25 mm made of rolled steel SN400B (JIS G 3136) for building structure, In the corner portion between the web and the web, one having a haunch with R (R = 40 mm) was used (see FIG. 6). Of course, the dimensions and the like of the extra-thick H-shaped steel may be appropriately selected according to the structural design of the fixing bracket 1, and the material of the steel material may be a general structural rolled steel (JIS G 3101) or a welded structural rolled steel (JIS). Other types of steel materials such as G3106) may be used.

(Reinforcing rib)
The reinforcing rib 4 is a halved trapezoidal plate made of a thick steel plate having a thickness of about 22 mm, and the base plate 2 and the top plate 3 have corners so that the plate surface is orthogonal to the base plate 2 and the top plate 3. Joined by meat welding or the like. In addition, the code | symbol 40 is a scallop provided so that the welding line of a reinforcement rib may not cross | intersect an R process part.

[Manufacturing method of fixing bracket of fallen bridge prevention device]
Next, a specific method for manufacturing the fixing bracket 1 will be described with reference to FIG. FIG. 6 is a perspective view showing a cutting position of the extremely thick H-section steel.

  First, as shown in FIG. 6, an unnecessary portion of the flange is cut along the length direction of the thick H-shaped steel according to the width of the base plate 2, and the above-mentioned thick H-shaped steel is fixed at the same time. Cut to a predetermined length according to the number and length of the metal fittings 1. Then, the top plate 3 is cut up and down alternately along the alternate long and short dash line in the figure corresponding to the shape of the top plate 3 to cut unnecessary portions of the web, and the top plate 3 is processed into a triangular shape with a rounded apex. To do. Of course, the cutting procedure may be reversed.

  The ultra-thick H-shaped steel is cut by locally heating and melting the steel material such as gas cutting or plasma cutting. Of course, as long as the extremely thick H-section steel can be easily cut in a short time, the cutting method is not limited to fusing, and other cutting methods may be used.

  Next, a bolt hole 20 is drilled at a predetermined position of the base plate 2 by cutting, and a connecting hole 30 is drilled at the center of the top plate 3 and the ring plate 31 by cutting.

  After that, the reinforcing rib 4 cut out from the thick steel plate different from the ultra-thick H-shaped steel into the above-mentioned half-cut trapezoidal shape so that the plate surface is orthogonal to the plate surfaces of the base plate 2 and the top plate 3, The base plate 2 and the top plate 3 are welded by fillet welding or the like.

  Finally, fillet welds the ring plate 31 to the top plate 3. Of course, the welding of the ring plate 31 to the top plate 3 may be performed in parallel with the welding of the reinforcing rib 4 or may be performed before or after the welding of the reinforcing rib 4.

  According to the fixing bracket 1 and the manufacturing method of the fixing bracket 1 according to the present embodiment described above, since the base plate 2 and the top plate 3 are cut out from the extremely thick H-shaped steel and integrally formed, complete melting is achieved. This eliminates the need for troublesome work such as welding, and can reduce the production cost.

  On the other hand, conventionally, the base plate and the top plate are joined by cutting out a thick steel plate having a thickness of about 22 mm into a predetermined shape, and applying a K-shaped groove to the joint edge of the top plate to complete penetration welding. It was given. For this reason, work time has been required, which has been a factor in increasing product costs.

  Further, according to the fixing bracket 1 and the manufacturing method of the fixing bracket 1, the base plate 2 and the top plate 3 are made of an extremely thick H-section steel formed by continuous rolling. A haunch with R is formed at the corner between the two. For this reason, a haunch with an R is also formed at the corner of the fixing bracket 1 between the base plate 2 and the top plate 3. Therefore, when the top plate is pulled in the out-of-plane direction of the base plate, stress is not concentrated on the corner portion between the base plate 2 and the top plate 3, and the resistance against bending of the base plate is large. It becomes unnecessary.

  On the other hand, when welding a conventional base plate and top plate, if a tensile stress acts in a direction perpendicular to the plate surface of the top plate, a tensile stress perpendicular to the weld line will work. The base plate could be bent and broken by being pulled out of the plane along the weld line.

  Furthermore, according to the fixing bracket 1 and the method of manufacturing the fixing bracket 1, since the reinforcing rib 4 is formed, the performance against the bending stress of the fixing bracket 1 is further enhanced, and the strength of the fixing bracket 1 is improved.

  As described above, the fixing bracket of the fallen bridge prevention device and the manufacturing method thereof according to the embodiment of the present invention have been described in detail. However, each of the above-described or illustrated embodiments is a specific embodiment for carrying out the present invention. However, the technical scope of the present invention should not be construed in a limited manner. In particular, although the dimensions and the like of the fixing bracket are described, this is merely an embodiment, and it is needless to say that it can be appropriately changed according to the design.

1, 1 ': Fixing bracket (fixing bracket of the fallen bridge prevention device)
2: Base plate 20: Bolt hole 3: Top plate 30: Connection hole 31: Ring plate 4: Reinforcement rib 40: Scallop 10: Fall bridge prevention device 11: Connection member 12: General chain (connection member)
13: Buffer chain (connection member)
S: Shackle B: Abutment (under structure)
H: Bridge girder (superstructure)

Claims (4)

A fixing bracket of a fall prevention device for preventing the upper structure of the bridge from falling from the lower structure,
A base plate made of a thick steel plate and a top plate having a plate surface perpendicular to the base plate, and the base plate and the top plate have an extremely thick H shape in which the thickness of the web is about the same as the thickness of the flange. A fixing bracket for a falling bridge prevention device, characterized by being cut out from steel and integrally molded. The fixing bracket for a falling bridge prevention device according to claim 1, wherein a bending reinforcing rib having a plate surface orthogonal to the base plate and the top plate is formed. A method of manufacturing a fixing bracket for a fall prevention device for preventing an upper structure of a bridge from falling from a lower structure,
A base plate made of thick steel plate and a top plate having a plate surface orthogonal to the base plate are cut out from an extremely thick H-shaped steel whose web thickness is about the same as the thickness of the flange, and is integrally formed. A method of manufacturing the fixing bracket of the apparatus. The fixing bracket of the falling bridge prevention device according to claim 3, further comprising a step of welding a bending reinforcing rib to oppose the bending stress acting on the top plate so as to be orthogonal to the base plate and the top plate. Manufacturing method.

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