JP2022099538A - Viaduct or bridge corner breakage prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corner breakage prevention device having a wide range of application in terms of installation space and workability, and capable of preventing viaducts and corner breakage of bridges.
SOLUTION: In a viaduct or a bridge, a corner breakage prevention device 2 installed straddling structures 9 installed adjacent to each other in the direction of the bridge axis, at an end where adjacent structures 9 face each other. It has two base plates 21 and 21 arranged respectively, a connecting member 22 for connecting the base plates 21 and 21 to each other, and an anchor bolt 23 for fixing the base plates 21 and 21 to the structure 9.
[Selection diagram] Fig. 2

Description

Application for application of Article 30, Paragraph 2 of the Patent Law is available. Railway Engineering Symposium Proceedings No. 24, published on July 6, 2nd year of Reiwa.

The present invention relates to a corner breakage prevention device mainly used for seismic retrofitting of railway girder viaducts and bridges.

For viaducts and bridges, different types of structures are installed along the direction of the bridge axis, depending on the difference in the supporting ground and the traffic conditions on the ground. In such viaducts and bridges, uneven displacements such as misalignment and corner breaks may occur between adjacent structures during an earthquake. For example, in an overhanging rigid frame viaduct or the like, misalignment is likely to occur, and in a girder type viaduct including a Gerber type rigid frame viaduct or a girder type viaduct, angular breakage is likely to occur due to differences in vibration characteristics between adjacent structures. Suppressing these uneven displacements that occur during an earthquake is important for ensuring the safety of running trains and vehicles.

In existing railway structures, ramen viaducts are usually installed at positions where there are no intersections such as roads, and ramen abutments and bridge girders using piers are installed at positions where there are intersections. FIG. 1 shows an example of an adjustable girder type rigid frame viaduct (overpass) structure 1 around a position where it intersects with a road. The viaduct structure 1 has an adjusting girder 13 at a connecting portion between the bridge girder 11 on the road and the ramen viaduct 12. Both ends of the bridge girder 11 in the front-rear direction are supported by rigid frame abutments 14, and the rigid frame abutment 14 supporting the rigid frame abutment 11 on the road has a different structural form from the rigid frame viaduct 12. Further, the weights of the bridge girder 11 and the adjustment girder 13 are significantly different. That is, at the position where it intersects the road, the structure changes from the rigid frame viaduct 12 to the rigid frame abutment 14, so the vibration properties are different, which causes a phase difference in response displacement during an earthquake, and as shown in FIG. 1, the vertical axis. Corner break 10 which is a deviation of the rotation angle is likely to occur.

Therefore, conventionally, as a method of suppressing the corner bending of an existing railway structure, adjustment of vibration properties between adjacent structures and installation of a device for physically suppressing uneven displacement have been considered.

As a method for adjusting the vibration properties of adjacent structures, Non-Patent Document 1 discloses a method of providing a damper brace. Further, as a device for physically suppressing corner breakage, as disclosed in Non-Patent Document 2, a corner breakage prevention device has been developed in which adjacent structures are connected to each other by a steel member in the line direction. This is a ramen viaduct equipped with a corner breakage prevention device on the fixed bearing side, and its effect has been partially verified by experiments and numerical analysis for railway viaducts.

Further, Patent Document 1 discloses a corner breakage prevention device applied to a connecting portion between an adjusting girder connected via a fixed bearing and a ramen viaduct.

Japanese Unexamined Patent Publication No. 2011-17192

Naoyuki Kita, Koji Yoshida, Motoyuki Okano, Masaki Seki: Practical application of compression type damper brace method for railway RC ramen viaduct, JSCE Proceedings F, Vol.63, No.3, pp.277-pp. 286, 2007.3 Naoki Maruyama, Masamichi Sogabe, Yukihiro Tanimura, Kazuhiro Harada, Toshiyuki Kuroiwa, Ryota Kasakura: Performance Evaluation of Corner Break Prevention Device for Railway Viaducts, Proceedings of Railway Mechanics, pp.162-169, 2009

However, in the method of installing a damper or a brace as in Non-Patent Document 1, it is necessary to secure a sufficient space for installation, and the place where the damper or brace can be installed is limited.

Further, the corner breakage prevention device described in Non-Patent Document 2 is installed on the upper surface of the cantilever slab, and the installation space is limited in the ballast track, and the construction in the daytime becomes difficult. There is a difficulty in workability.

Further, the corner breakage prevention device described in Patent Document 1 is applied only to fixed bearings, and in this case, although a certain effect can be obtained for the entire viaduct, it is directly applied to the girder on the movable bearing. Since it is not installed in, there is a problem that the corner break on the movable bearing becomes relatively large.

As described above, in either case, there is a problem that the applicable range is limited, and it can be constructed without hindering the running of the railway on the track, and it can be used for railway ramen abutments, etc. where corner breaks are noticeable. There is a need for an applicable corner breakage prevention device.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a corner breakage prevention device having a wide range of application in terms of installation space, workability, etc., and capable of preventing viaducts and corner breaks in bridges. And.

In order to solve the above problems, the present invention is a corner breakage prevention device installed across structures installed adjacent to each other in the direction of the bridge axis in a viaduct or a bridge, and the adjacent structures are connected to each other. It is characterized by having two base plates arranged at opposite ends, a connecting member for connecting the base plates to each other, and an anchor bolt for fixing the base plate to the structure.

The corner breakage prevention device may have a bracket for connecting the two base plates and the connecting member.

When the corner breakage prevention device is provided on the viaduct or the movable bearing side of the bridge, a clearance corresponding to the displacement of the structure in the bridge axial direction is provided. In that case, the clearance may be provided by making the bolt hole for the anchor bolt formed in one of the base plates a long hole long in the bridge axis direction. Alternatively, the clearance may be provided by connecting the connecting portion between the connecting member and one of the base plates with a gap provided in the bridge axis direction.

It is preferable that the yield strength Py in the tensile direction of the connecting member satisfies the formula (1).
Py = My / 2L ... (1)
My: Rotational strength required to suppress corner breakage of the structure L: Distance from the center of the structure to the corner breakage prevention device

The rotation proof stress My is obtained by a simulation modeling the structure, and is preferably the rotation proof stress when the amount of angular bending of the structure becomes a certain value or less. When mounted at a position 4.5 m from the center of the structure having the overpass, it is preferable that the connecting member has a horizontal strength of 400 kN or more in the direction of the bridge axis. Further, it is preferable that the total shear strength of the anchor bolt is larger than the horizontal strength of the connecting member.

Further, according to the present invention, the corner breakage prevention device can be installed on the outside of the track of the viaduct or the structure of the bridge.

According to the present invention, adjacent structures are connected to each other with a simple structure, each structure having a different structure is suppressed from vibrating at a different natural period, and the relative displacement between adjacent structures is physically determined. Can be suppressed. Moreover, since it can be installed on a viaduct or the lower surface or side surface of a bridge, it can be installed without requiring a large space and without hindering the running of a railway or the like on an orbit on the bridge.

It is a perspective view which shows the example of a viaduct structure. It is a plan view of the corner bending prevention device as an example of an embodiment of this invention, (a) is for fixed bearings, (b) is for movable bearings. It is a side view of the corner bending prevention device as a different example of an embodiment of this invention, (a) is for a fixed bearing, (b) is for a movable bearing. It is a perspective view which shows the installation example of the corner bending prevention device shown in FIG. It is a perspective view which shows the different installation example of the corner bending prevention device shown in FIG. It is a perspective view which shows the further different installation example of the corner bending prevention device shown in FIG. It is a perspective view which shows the installation example of the corner fold prevention device shown in FIG. It is a figure which shows the example of the analysis modeling of a viaduct structure. It is a graph which modeled the behavior of the corner break prevention device, (a) is the case of the corner break prevention device for fixed bearings, and (b) is the case of the corner break prevention device for movable bearings. It is a graph of the simulation result which shows the relationship between the rotational yield strength and the corner bending. It is a graph of the simulation result which shows the relationship between the tensile yield strength of the corner break prevention device and the corner break occurrence ratio.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, the elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

The corner breakage prevention device 2 according to the embodiment of the present invention can be constructed from the outside of the viaduct or the track of the bridge to solve the problem of the above-mentioned prior art installed on the upper surface of the cantilever slab. FIG. 2A shows a corner breakage prevention device 2 as an example of the embodiment of the present invention. The corner break prevention device 2 is installed in the viaduct structure 1 shown in FIG. 1, for example, straddling the bridge girder 11 and the adjustment girder 13 on the road, and is applied to prevent the corner break 10. In the following description, the rigid frame viaduct 12, the adjusting girder 13, the rigid frame abutment 14, and the like are collectively referred to as a structure 9.

The corner breakage prevention device 2 includes two flat plate-shaped base plates 21 and 21, connecting members 22 for connecting the base plates 21 and 21 to each other, and anchor bolts 23 for fixing the base plates 21 and 21 to the structure 9. is doing. The base plate 21 is provided with a bolt hole 31 for inserting the anchor bolt 23. As the anchor bolt 23, various general post-installed anchors can be used, but an adhesive anchor is desirable in consideration of the influence of vibration and the like. As the connecting member 22, a member having a predetermined cross-sectional performance, which will be described later, such as H-shaped steel is used, and is fixed to the base plates 21 and 21 by welding or the like.

The corner breakage prevention device 2 shown in FIG. 2A is an example when it is used on the fixed bearing side, and when it is used on the movable bearing side, it is an adjacent structure as shown in FIG. 2B. When the distance between the 9 base plates changes, a clearance (play space) is used so that the distance between the base plates 21 and 21 can be changed. That is, in the example of FIG. 2B, the bolt hole 31 of one of the base plates 21 is a long hole long in the bridge axis direction, and it is possible to cope with the case where the adjacent structures 9 are horizontally displaced and the spacing is changed. It has become like. This is effective because the movable bearing does not restrain the expansion and contraction of the structural member due to a temperature change or the like.

FIG. 3 shows a different embodiment of the corner breakage prevention device 2, in which two flat plate-shaped base plates 21 and 21 and a connecting member 22 are connected via a bracket 24, respectively. The bracket 24 has a surface that abuts on the base plate 21 and the flange 32 of the connecting member 22, respectively, and the bracket 24 and the connecting member 22 are connected by bolts 25. Alternatively, the base plate 21 and the bracket 24 may be integrally molded. FIG. 3A is an example of the case where it is used on the fixed bearing side, and when the horizontal distance is variable such as a movable bearing, the connecting member 22 and the bracket 24 are shown as shown in FIG. 3B. By connecting with bolts 6 with a gap provided in the direction of the bridge axis, there is a clearance that can be used when the distance between the structures 9 changes due to a temperature change or the like.

4 to 7 show an installation example of the corner breakage prevention device 2 shown in FIG. 2 or FIG. As described above, the corner breakage prevention device 2 according to the embodiment of the present invention is characterized in that it can be constructed from the outside of the viaduct or the track of the bridge.

FIG. 4 shows an installation example of the corner breakage prevention device 2 of FIG. The corner breakage prevention device 2 is installed so as to straddle the tips of adjacent cantilever slabs 41, and the base plate 21 is in contact with the lower surface of the cantilever slab 41 of the viaduct or bridge structure 9. In this example, first, a hole for the anchor bolt 23 is formed on the lower surface of the cantilever slab 41 at a position where the base plate 21 is attached so as to match the bolt hole 31 of the base plate 21. Then, by abutting the base plate 21 at a predetermined position and driving the anchor bolts 23, the two base plates 21 and 21 are fixed to the lower surfaces of the adjacent cantilever slabs 41, respectively, and the corner breakage prevention device 2 and the structure 9 are fixed. And are integrated. As a result, the phase difference between adjacent structures 9 is suppressed, and corner breakage is prevented. For example, in the case of a girder with a small number of main girders, since the overhang length of the cantilever slab 41 is relatively large, it is often possible to secure a space for connecting the lower surfaces of the cantilever slabs 41 of adjacent girders. Such a construction method is useful. As described above, according to the present embodiment, by attaching the corner breakage prevention device 2 to the lower surface of the viaduct structure, it is possible to carry out the construction in the daytime without affecting the track of the viaduct.

FIG. 5 shows different installation examples of the corner breakage prevention device 2 of FIG. 2, and the corner breakage prevention device 2 is installed so as to straddle the main beams 42 of the adjacent cantilever slabs 41. In the example of FIG. 5, a hole for the anchor bolt 23 is formed on the side surface of the main beam 42 of the structure 9 at a position where the base plate 21 is attached so as to match the bolt hole 31 of the base plate 21. Then, by abutting the base plate 21 at a predetermined position and driving the anchor bolts 23, the two base plates 21 and 21 are fixed to the side surfaces of the main beam 42, respectively, and the corner breakage prevention device 2 and the structure 9 are integrated. Will be done.

FIG. 6 shows a further different installation example of the corner breakage prevention device 2 of FIG. 1, in which the corner breakage prevention device 2 is installed so as to straddle the ground coverings 43 of the adjacent cantilever slabs 41. In the example of FIG. 6, a hole for the anchor bolt 23 is formed on the outer surface of the ground cover 43 at a position where the base plate 21 is attached so as to match the bolt hole 13 of the base plate 21. Then, by abutting the base plate 21 at a predetermined position and driving the anchor bolts 23, the two base plates 21 and 21 are fixed to the outer surfaces of the ground cover 43, respectively, and the corner breakage prevention device 2 and the structure 9 are integrated. Be made. In many viaduct structures, since the ground cover 43 is continuous at the tip of the cantilever slab 41, it is possible to construct the ground cover 43 in this way.

Further, FIG. 7 shows a construction example in which the base plates 21 and 21 are attached to different structural members. 7 (a) shows one attached to the lower surface of the main beam 42 and the other attached to the side surface of the girder 44 of the ramen abutment 14, FIG. 7 (b) shows one to the lower surface of the cantilever slab 41 and the other to the wall type. This is the case when it is attached to the frame of the abutment 15. In the case of the rigid frame abutment 14 and the wall-type pier 15, the installation location is considered to have a relatively large degree of freedom, so the installation position in the paired superstructure is assumed to be the cantilever slab 41, main beam 42, etc. Ru. In this case, since the mounting directions of the two base plates 21 and 21 are different, the base plate 21 and the connecting member 22 are connected via a bracket 24 having a corresponding shape. Also in the case of FIG. 7, it is possible to carry out the construction without affecting the track of the viaduct.

In the embodiment of FIGS. 4 to 7, the corner breakage prevention device 2 can be applied regardless of the presence or absence of clearance.

As described above, according to the present invention, the viaduct for railways and the corner breakage prevention device 2 for bridges can be installed without being installed on the track. In each of the above embodiments, it is preferable to use a net, a chain, or the like to provide means for preventing the broken corner breakage prevention device 2 from falling downward when the corner breakage prevention device 2 is damaged during an earthquake or the like.

Next, the specifications required for applying the corner breakage prevention device 2 of the present invention to a railroad rigid frame abutment or a railroad pier will be described.

Numerical analysis using a model of a typical overhead bridge structure group consisting of a rigid frame viaduct 12 for railways, a PC girder (bridge girder 11), a rigid frame abutment 14, an adjustment girder 13, etc. as shown in FIG. From the analysis results, the specifications of the corner fold prevention device 2 and the effect of suppressing corner folds were quantitatively clarified. As a result, the specifications of the optimum corner breakage prevention device 2 applicable to structures such as viaducts and bridges including the rigid frame abutment 14 were obtained.

FIG. 8 shows an example of modeling the viaduct structure 1. The ramen abutment RA is installed at a position straddling the central road, and the ramen viaduct R is installed before and after the ramen abutment RA in the direction of the bridge axis. F in FIG. 8 represents a fixed bearing, and M represents a movable bearing. This model is a typical pattern of viaduct structures.

Further, as the behavior of the corner breakage prevention device 2, the relationship between the horizontal displacement δ and the horizontal force P was modeled as shown in FIG. FIG. 9A shows a model of behavior when a corner breakage prevention device without a clearance is provided, and FIG. 9B shows a behavior model when a clearance is provided.

The effect of the corner break prevention device 2 differs depending on the installation position in the direction perpendicular to the bridge axis from the center of the structure 9, but if the corner break prevention device 2 has a certain degree of rotational rigidity, the corner break prevention device 2 is prevented. It is known that the effect can be grasped by the rotational yield strength (yield moment) My of the device 2.
My = 2Py × L ・ ・ ・ (1')
Py: Yield strength in the tensile direction of the connecting member of the corner breakage prevention device L: Distance from the center of the structure to the corner breakage prevention device

FIG. 10 shows a simulation result of response analysis by applying a seismic wave when the corner breakage prevention device 2 showing the behavior shown in FIG. 9 is used in the viaduct structure shown in FIG. From FIG. 10, it can be seen that the decrease in the amount of corner folds reaches a plateau when the rotational proof stress My is about 4000 kN · m, and even if the rotational proof stress My is further increased, the effect of preventing corner folds hardly increases. That is, in the corner fold prevention device 2 according to the embodiment of the present invention, the rotational proof stress obtained by the yield strength Py of the connecting member 22 and the distance L from the center of the structure to the corner fold prevention device 2 may be a predetermined value. On the premise that the model behaves as shown in FIG. 9, the rotational yield strength My is, for example, about 4000 kN · m, and the effect of the corner breakage prevention device 2 can be efficiently exhibited. As a result, when the corner breakage prevention device 2 changes the construction position for some reason, or when it is diverted to a structure having substantially the same structure, the design can be easily changed by using the formula (1'). ..

An example of specific specifications of the corner breakage prevention device 2 will be described. For example, when the distance L from the center of the structure to the corner breakage prevention device 2 when installed at the position shown in FIG. 4 is 4.5 m, the yield of the connecting member 3 of the corner breakage prevention device 1 is determined from the formula (1'). The bearing capacity (load) Py is
Py = My / 2L ... (1)
My: Rotational strength required to suppress corner breakage of the structure L: Obtained by the distance from the center of the structure to the corner breakage prevention device. Further, FIG. 11 shows the results of obtaining the corner break ratios in the case of no reinforcement and in the case of reinforcement with the corner break prevention device 2 having a rotational strength by simulation. From FIG. 11, when the tensile yield strength (load) Py of the connecting member 22 of the corner breakage prevention device 2 is about 400 kN, the corner breakage occurrence ratio becomes remarkably low, and even if the yield strength Py exceeds 400 kN, the corner breakage prevention effect changes. It turns out that there is no such thing. That is, when the yield strength Py is 400 kN, the effect of the corner breakage prevention device can be efficiently exhibited. As an example of the connecting member 22 having a yield strength (load) Py of about 400 kN, H-shaped steel of H-100 × 100 (SS400) can be used. The material of the connecting member 22 may be, for example, CFT or the like as long as it has the required strength, in addition to the steel material.

In addition, when a member other than the connecting member 22 yields when a large horizontal force such as an earthquake acts, it is assumed that the load-displacement relationship becomes complicated, and repair is difficult if the viaduct or the slab of the bridge structure is destroyed. Therefore, it is preferable to design the corner breakage prevention device 2 so that the base plate 21 and the anchor bolt 23 do not yield before the connecting member 22.

That is, the cross-sectional area and the number of anchor bolts 23 are designed so that the total shear strength of the anchor bolts 23 is larger than the tensile strength of the connecting member 22. The tensile strength of the anchor bolt 23 may be sufficient to support the weight of the corner breakage prevention device 2. When the connecting member 22 and the bracket 24 are connected by the bolt 25, the cross-sectional area and the number of the bolt 25 are designed so that the tensile strength of the bolt 25 does not fall below the tensile strength of the connecting member 22. The plate thickness of the base plate 21 and the bracket 24 may be determined based on the strength design of a normal steel structure. In the present invention, steel materials are suitable for the base plate 21, bracket 24, bolts 25, and the like, but other materials having the same characteristics and strength as the steel materials are not excluded.

As described above, according to the corner breakage prevention device according to the embodiment of the present invention, in the case of viaducts for railways, bridges, etc., it is possible to suppress the vibration of each structure having a different structure in a different natural period at the time of an earthquake, and to prevent the adjacent structure from vibrating. By physically suppressing the relative displacement between the structures, it is possible to prevent corner breaks that occur between adjacent structures and improve the runnability of trains and the like.

Moreover, it can be applied to an overpass where corner bending is remarkable, and it can be attached to the lower surface or the side surface of a structure, and has a lot of freedom in the installation position. Therefore, the construction work can be performed during the daytime without affecting the track of the viaduct and without hindering the running of the railway or the like.

Further, by clarifying the strength required for the member of the corner breakage prevention device 2 and the corner breakage prevention effect, measures for reinforcing viaducts and bridges are promoted.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical idea described in the claims, and of course, the technical scope of the present invention also includes them. It is understood that it belongs to.

The present invention is useful as a corner breakage prevention device at positions of different types of structures adjacent to each other in the bridge axial direction, such as viaducts and bridges.

1 Viaduct structure 2 Corner break prevention device 9 Structure 10 Corner break 11 Bridge girder 12 Rahmen viaduct 13 Adjustment girder 14 Rahmen pier 15 Wall type pier 21 Base plate 22 Connecting member 23 Anchor bolt 24 Bracket 25 Bolt 31 Bolt hole 32 Flange 41 Cantilever Slab 42 Main beam 43 Underpass 44 Girder

Claims (10)

A corner breakage prevention device installed across structures installed adjacent to each other in the direction of the bridge axis in a viaduct or a bridge.
Two base plates arranged at the ends where the adjacent structures face each other, and
A connecting member that connects the base plates to each other,
An anchor bolt for fixing the base plate to the structure, and an angle breakage prevention device for a viaduct or a bridge. The viaduct or bridge corner breakage prevention device according to claim 1, further comprising a bracket for connecting the two base plates and the connecting member. The viaduct or angle breakage prevention device for a bridge according to claim 1 or 2, wherein a clearance corresponding to a displacement in the bridge axial direction of the structure is provided. The viaduct or bridge according to claim 3, wherein the clearance is provided by forming a bolt hole for the anchor bolt formed in one of the base plates into a long hole long in the bridge axis direction. Anchor break prevention device. The third aspect of the present invention, wherein the connecting portion between the connecting member and one of the base plates is connected with a gap provided in the direction of the bridge axis to provide the clearance. Anti-breaking device for viaducts or bridges. The viaduct or corner breakage prevention device for a bridge according to any one of claims 1 to 5, wherein the yield strength Py in the tensile direction of the connecting member satisfies the formula (1).
Py = My / 2L ... (1)
My: Rotational strength required to suppress corner breakage of the structure L: Distance from the center of the structure to the corner breakage prevention device The rotational proof stress My is obtained by a simulation modeling the structure, and is characterized by the rotational proof stress when the amount of angular bending of the structure becomes a certain value or less, according to claim 6. Anti-breaking device for viaducts or bridges. Any of claims 1 to 7, wherein the connecting member has a horizontal strength of 400 kN or more in the direction of the bridge when it is attached at a position 4.5 m from the center of the structure having an overpass. The breakage prevention device for viaducts or bridges according to item 1. The viaduct or corner breakage prevention device for a bridge according to any one of claims 1 to 8, wherein the total shear strength of the anchor bolt is larger than the horizontal strength of the connecting member. A method for preventing an angular break in a viaduct or a bridge, which comprises installing the corner break prevention device according to claims 1 to 9 on the outside of the track of the viaduct or the structure of the bridge.

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