JP7017879B2 - A bridge equipped with a function-separated shock absorber and a function-separated shock absorber - Google Patents

Description

The present invention is a bridge provided with a function-separated type shock absorber and a function-separated type shock absorber having excellent deformation ability and energy absorption ability with respect to a load in both tensile and compressive directions in the material axial direction, as compared with a conventional rod-shaped vibration damping member. For example, it can be installed between the end of the bridge girder and the abutment supporting the end of the bridge girder and used as a shock absorbing member at the time of an earthquake.

Various rod-shaped vibration-damping members such as vibration-damping braces that also serve as vibration-damping members and structural members have been developed and commercialized to enhance the seismic performance and vibration-damping performance of structures.

For example, in Patent Document 1 and Patent Document 2, a buckling restraint type axial force bearing member using a core material made of a flat plate or a steel material having a cross section and a restraining material made of angle steel that restrains the buckling deformation thereof is described. Are listed.

Further, in Patent Document 3, the outer circumference of the steel core material is covered with a buckling restraining concrete member via an unbonded layer, and the outer circumference of the buckling restraining concrete member is covered with a steel pipe to reinforce the shaft yield type elasto-plastic history. The improved technique of the brace is described.

FIGS. 20 (a) and 20 (b) show a specific example of a buckling restraint type rod-shaped vibration damping member using a flat plate core material as an example of a conventional rod-shaped vibration damping member.

The basic configuration is to form joints 31 and 32 with enlarged cross sections at both ends of the core material 30 body as an energy absorber made of low yield point steel or ordinary steel, and deform the core material 30 body from all sides. It is held by angle steel as a restraining member 33, and the deformation restraining members 33 are tightened with a high-strength bolt 35 via a spacer 34 so that the core material 30 body does not buckle.

In this example, the core material 30 and the deformation restraining member 33 are provided with high-strength bolts 35 at two locations, the fixed side joint portion 31 on the back side and the movable side joint portion 32 on the front side in FIG. 20 (a). The high-strength bolt 35 of the movable side joint portion 32 is joined in the axial direction along the elongated hole 33a formed in the deformation restraining member 33 when an axial tensile force or a compressive force is applied to the core material 30. It is slidable.

That is, when the axial tensile force acts on the core material 30, the core material 30 extends in the elastic range or the elasto-plastic range, and when the axial compressive force acts on the core material 30, the core material 30 has the elastic range or the elastic range. It shrinks in the elastic plastic range, and the deformation restraint member 33 is substantially free from axial force.

Further, when a compressive force in the axial direction acts on the core material 30, the deformation restraining member 33 restrains the core material 30 body from all sides, so that buckling deformation of the core material 30 body does not occur, so that vibration damping occurs. It is possible to fully demonstrate the energy absorption capacity as a member.

FIGS. 21 (a) and 21 (b) show a specific example of a buckling restraint brace using a cross core material as an example of a conventional rod-shaped vibration damping member, and the cross section of the core material 30 body is referred to as a cross section. The configuration and working effects other than the above points are the same as in the case of the flat plate of FIG. 18, but when the same deformation occurs, the core material 30 has a larger cross section and therefore has a higher energy absorption capacity.

By the way, in bridges such as road bridges, the girder length is sufficient on the substructure side so that the end of the bridge girder, which is the superstructure, does not collapse from the substructure such as the pier or pier that supports the end of the bridge girder during a large-scale earthquake. In addition, the bridge girder end on the superstructure side and the bridge pier and pier on the substructure side are connected with a collapse prevention material, and especially in recent years, the rod-shaped vibration damping member is used as a bridge collapse prevention material. Consideration is being made to combine the functions, and to use it as a single bridge collapse prevention material.

Japanese Unexamined Patent Publication No. 2000-265706 Japanese Unexamined Patent Publication No. 2006-328688 Japanese Unexamined Patent Publication No. 2014-031654

In the conventional design of rod-shaped vibration damping members, the core material was always yielded during a large-scale earthquake to absorb seismic energy by historical damping, but it is also required to take design measures that take into account unexpected earthquakes. There is. In addition, since the compressive load acts alternately with the tensile load on the rod-shaped vibration damping member, the deformation capacity and seismic energy absorption capacity should be doubled by attaching a core material that yields under the compressive load. Can be done.

For example, when used by attaching it between the bridge girder and the abutment that supports the bridge girder, if the core material of the rod-shaped vibration damping member has already broken in the repeated history during a large-scale earthquake, it can be used as a bridge collapse prevention material after that. Seismic energy cannot be absorbed for the deformation behavior of.

Further, when mainly designing a bridge collapse prevention material, as a bridge collapse prevention system, it is not necessary to plastically deform the core material until the function of the bearing is lost, and a structure capable of following the deformation of the bearing is required during that time. Ru. In other words, if the function of the bearing is lost due to unexpected seismic behavior, the core material should be plastically deformed, and the design timing for plastically deforming the core material differs depending on the purpose of use.

The present invention has been made in view of such circumstances, and has extremely high deformation capacity and energy absorption capacity for both tensile and compressive loads during an earthquake, and is the largest earthquake (level 2) within a conceivable range. It is possible to respond not only to earthquake motion) but also to unexpected large earthquakes beyond the range of level 2, for example, bridge collapse prevention installed between the end of the bridge girder and the abutment that supports the end of the bridge girder. It is an object of the present invention to provide a bridge provided with a function-separated type shock absorber and a function-separated type shock absorber suitable as materials.

The present invention is a rod-shaped function-separated shock absorber that has joints at both ends in the material axial direction and expands and contracts in the material axial direction by receiving tensile and compressive loads, and is plastically deformed by receiving a tensile load. In the first displacement section on the pulling side set as a region, the upper limit of the first displacement section is while the specific first axially deforming member on the pulling side constituting the shock absorber is elastically deformed or plastically deformed. In the second displacement section on the pulling side, which exceeds the first displacement section and is set as the second plastic deformation region on the pulling side, the displacement is constrained in the above. In the compression section on the compression side, which is configured such that a specific second axially deforming member is elastically deformed or plastically deformed and is set as a plastic deformation region on the compression side by receiving a compressive load, the compression constituting the shock absorber. It is characterized in that the axially deforming member on the side is elastically deformed or plastically deformed.

In the function-separated shock absorber according to claim 1, the second axially deforming member exceeds the second displacement section and is set as a third plastic deformation region under a tensile load. In the section, a specific third axially deforming member constituting the shock absorbing device may be elastically deformed or plastically deformed.

Further, in the function-separated type impact absorbing device according to claim 1 or 2, a specific axial displacement member on the pulling side constituting the shock absorbing device is connected to one of the joint portions by receiving a tensile and compressive load. It is possible to have a configuration having a displacement section set as a gap region in which the displacement is substantially non-resistive in the tensile direction and the compression direction in a separated state.

Further, in the function-separated type impact absorber according to any one of claims 1 to 3, a fracture-inducing portion that breaks under a set tensile load is provided on a specific axially deforming member on the tension side constituting the impact absorber. Thereby, it is possible to prevent the damage from extending to other parts when an unexpected tensile load is applied, and it is possible to recover the damage at an early stage and extremely economically. In this case, the fracture-inducing portion may be a recess or a through hole for the purpose of cross-sectional defect.

As the material of the axially deformable member, low yield point steel or shape memory alloy having excellent deformability can be used in addition to ordinary steel which is a JIS material, depending on the required performance.

The function-separated impact absorber of the present invention can be installed between the substructure and superstructure of a bridge configured to allow the destruction of bearings by seismic motion of level 2 or higher, and further, level 2 seismic motion or higher. Even if one core material is destroyed by the earthquake motion of the above, it can be dealt with by layering the yield load of the core material so that the other core material functions as a shock absorber.

The function-separated type shock absorber of the present invention clarifies each function by separating the core material, which is the absorbent material of the shock absorber of the rod-shaped vibration damping member, into two, and the yield load of the core material can be layered. realizable. In addition, by providing a clearance length between the separated core materials, in addition to adding the ability to follow the deformation at all times, it is possible to absorb the impact even with the compressive force that the conventional cable type could not handle. Become.

Further, it is provided with a compression side displacement section set as a plastic deformation region on the compression side by receiving a compression load, and in the compression side displacement section, the compression side axial deformation member constituting the shock absorbing device is elastically deformed. Or, because it is configured to be plastically deformed, it has excellent deformation capacity and energy absorption capacity in both tensile and compression directions in the material axis direction. It can be used as a shock absorbing member of time.

The first embodiment of the function-separated shock absorber of the present invention is illustrated. FIG. 1 (a) shows an initial state, and FIG. 1 (b) shows a pulling force in the direction of the bridge axis acting on the left core. FIG. 1 (c) is a perspective view of the final fractured state when the joint is tentatively fractured, in which the material is plastically deformed and operated after the shaft yields. It is an exploded perspective view of the function-separated type shock absorber shown in FIG. The end portion of the end portion of the first deformed core material is illustrated, FIG. 3 (a) is a perspective view showing a state before the connecting portion is broken, and FIG. 3 (b) is a perspective view after the connecting portion is broken. It is a perspective view which shows the state. 4 (a) and 4 (b) are cross-sectional views taken along the line 1 (a) and FIG. 15 (a), respectively. An example of installation of the shock absorber of the present invention is illustrated, and it is a side view of the function-separated type shock absorber installed between the end of the bridge girder and the abutment supporting the bridge girder. It is a side view which shows the tensile deformation in the operating state of the function separation type shock absorber of this invention installed between a bridge girder end part and an abutment. It is a side view which shows the compression deformation in the operating state of the function separation type shock absorber of this invention installed between a bridge girder end part and an abutment. It is explanatory drawing which shows the behavior by tension and compression load of the 1st and 2nd deformed core material and displacement core material. It is a graph which shows the load-displacement design curve of FIG. It is a graph which shows the load-displacement design curve when the load (compression and tensile force) in the bridge axis direction are applied to the function-separated type impact absorber of FIG. There is an abutment on the compression side and the displacement is limited. The pull side is an example of a design that breaks at the maximum design load. The second embodiment of the function-separated shock absorber of the present invention is illustrated. FIG. 11 (a) shows an initial state, FIG. 11 (b) shows a tensile force acting on the core material on the left side. FIG. 11 (c) is a perspective view of the final fractured state when the core material on the right side subsequently undergoes plastic deformation after the shaft yields and the joint portion is fractured. It is a graph which shows the load-displacement design curve when the load (compression and tensile force) in the bridge axis direction are applied to the function-separated type impact absorber shown in FIG. This is an example of a design in which the divided core material undergoes axial yielding due to the layering of the yield load, then undergoes plastic deformation, and breaks at the maximum design load. A third embodiment of the function-separated shock absorber of the present invention is illustrated. FIG. 13 (a) shows an initial state, FIG. 13 (b) shows a tensile force acting on the core material on the left side. It is a perspective view of the state in which it was operated. It is a graph which shows the load-displacement design curve when the load (compression and tensile force) in the bridge axis direction are applied to the function-separated type impact absorber shown in FIG. A fourth embodiment of the function-separated shock absorber of the present invention is illustrated. FIG. 15 (a) shows an initial state, and FIG. 15 (b) shows that the core material on the left side is compressed and pulled after the shaft yields. It is a perspective view of the operating state in which the tensile load reaches the yield load of the core material on the right side and is plastically deformed after repeated displacements. It is a graph which shows the load-displacement design curve when the load (compression and tensile force) in the bridge axis direction are applied to the function-separated type impact absorber shown in FIG. It is a graph which shows the load-displacement design curve when the load (compression and tensile force) in the bridge axis direction are applied to the function-separated type shock absorber of the 5th Embodiment of the function-separated type shock absorber of this invention. It is a graph which shows the load-displacement design curve when the load (compression and tensile force) in the bridge axis direction are applied to the shock absorber of the sixth embodiment of the function separation type shock absorber of this invention. It is a graph which shows the stress-strain curve of the typical steel material used as a core material in the function separation type shock absorber of this invention. FIG. 20 (a) is a partially transparent perspective view showing an example of a buckling restraint brace (in the case of a flat plate core material) as a conventional rod-shaped vibration damping member, and FIG. 20 (b) is a cross-sectional view in a direction perpendicular to the axis. FIG. 21 (a) is a partially transparent perspective view showing another example (in the case of a cross core material) of a buckling restraint brace as a conventional rod-shaped vibration damping member, and FIG. 21 (b) is a cross-sectional view in the direction perpendicular to the axis. ..

[Embodiment 1]
1 to 10 are the first embodiments of the present invention, and show a function-separated shock absorber (hereinafter referred to as “collapse prevention material”) and an installation example thereof. In the figure, a plurality of bridge collapse prevention materials 3 and bearings 4 are installed between the end of the bridge girder 1 and the abutment 2 supporting the end of the bridge girder 1 (see FIGS. 5, 6 and 7), and both of them are bridge girders 1. It is installed at right angles to the bridge axis. Reference numeral 17 is a telescopic device that expands and contracts according to the behavior between the bridge girder 1 and the abutment 2.

The bridge collapse prevention material 3 is configured in a rod shape that expands and contracts in the material axis direction of the bridge collapse prevention material 3 (hereinafter, “bridge axis direction of bridge girder 1”), and joint portions 5 and joint portions 6 are attached to both ends in the bridge axis direction, respectively. Has been done. The joint portion 5 is fixed to the side surface of the abutment 2, and the joint portion 6 is fixed to the lower end surface of the end portion of the bridge girder 1.

Further, the first displacement section L ₁ on the tension side that is elasto-plastically deformed by the load in the bridge shaft tensile direction between the joint portion 5 and the joint portion 6 and the compression side that is elasto-plastically deformed by the load in the bridge shaft compression direction. Displacement sections L ₃ are provided respectively (see FIGS. 1 and 8). The first displacement section L ₁ on the tension side is provided on the joint portion 5 side, and the displacement section L ₃ on the compression side is provided on the joint portion 6 side.

Between the displacement section L ₃ on the compression side and the joint portion 6, there is a displacement section L ₂ set as a clearance region in which the displacement core material 8 receives a tensile and compressive load and is displaced in the axial tension direction and the axial compression direction . It is provided. The displacement section L ₂ is provided adjacent to each other on the same material axis as the first displacement section L ₁ on the pulling side and the displacement section L ₃ on the compression side (see FIGS. 1 and 8). The displacement core member 8 is displaced in the axial tension direction and the axial compression direction with substantially no resistance in a state where the connection with the joint portion 5 is disconnected .

The first deformed core material 7A and the second deformed core material 7B are installed in the first displacement section L ₁ on the tension side and the displacement section L ₃ on the compression side, respectively, and the displacement core is in the displacement section L ₂ set as the clearance region. Material 8 is installed.

The first and second deformed core materials 7A and 7B are formed in the shape of a single elongated flat plate continuous in the bridge axis direction, and the enlarged diameter portions 7a and 7b and the first deformed core material 7A are formed at both ends in the bridge axis direction. An enlarged diameter portion 7c is formed between the second deformed core material 7B and the second deformed core material 7B, respectively. The enlarged diameter portions 7a, 7b, and 7c are all formed in a substantially cross-shaped cross section.

Further, a flat plate-shaped connecting portion 7d extending to the joint portion 5 side with the same width as the enlarged diameter portion 7a is formed at the end portion of the first deformed core material 7A on the joint portion 5 side, and the connecting portion 7d rotates to the joint portion 5. It is freely connected. Further, a fracture-inducing recess 7e and a buckling restraint rib 7f are formed at the boundary between the enlarged diameter portion 7a and the connecting portion 7d (see FIGS. 3 (a) and 3 (b)).

The rupture-inducing recess 7e is provided when a tensile load in the bridge axial direction acts between the joint portions 5 and 6 in excess of the design value.
It is provided to prevent damage such as breakage from reaching other parts by intentionally breaking the fracture-inducing recess 7e. In addition to the recess as shown in the figure, even if it is simply a through hole. good.

Further, the buckling restraint rib 7f is formed so that the connecting portion 7d does not buckle due to the compressive load acting between the joint portions 5 and 6 in the bridge axial direction. The buckling restraint rib 7f is in contact with the end faces of the enlarged diameter portions 7a, 7a in the same vertical plane as the enlarged diameter portions 7a, 7a of the first deformed core material 7A at the center of both the upper and lower surfaces of the connecting portion 7d. It is formed in and transmits only the axial compressive load and not the tensile load.

Further, the first and second deformable core materials 7A and 7B are formed so as to be elasto-plastically deformed before the connecting portion 7d with respect to the tensile load acting in the bridge axial direction, and for example, the cross section having a smaller diameter than the connecting portion 7d. It is either formed or made of low yield point steel (eg, LY225 standard, etc.) (see Figure 19).

The displacement core material 8 is formed in a substantially cross-shaped cross section that is elongated and continuous in the bridge axis direction, and diameter-expanded portions 8a and 8a are formed at both ends in the bridge axis direction. The enlarged diameter portion 8a is formed in a substantially cross-shaped cross section having a larger diameter than the displacement core material 8. Further, a flat plate-shaped connecting portion 8b having the same width as the enlarged diameter portion 8a and extending to the joint portion 6 side is formed at the end portion on the joint portion 6 side, and the connecting portion 8b is rotatably connected to the joint portion 6.

Further, the displacement core material 8 is formed so as not to yield and fracture before the connecting portion 7d with respect to a tensile load in the bridge axis direction. For example, it is formed from SM400) (see Fig. 19).

The buckling restraining material 9 is continuous in the bridge axis direction of the first and second deformed core materials 7A and 7B and the displacement core material 8, and is the total length of the first and second deformed core materials 7A and 7B and the displacement core material 8. It has almost the same length and is formed in a substantially equilateral mountain shape in cross section.

Further, the first and second deformed core materials 7A, 7B and the displacement core material 8 are installed so as to sandwich the first and second deformed core materials 7A, 7B and the displacement core material 8 on the outside in the direction perpendicular to the axis. There is. Then, a plurality of tightening bolts 10a and guide bolts 10b are joined to both side surfaces of the enlarged diameter portions 7a, 7c of the first and second deformed core materials 7A, 7B and the enlarged diameter portions 8a, 8a of the displacement core material 8. , Between the enlarged diameter portions 7a and 7c, between the enlarged diameter portions 7b and 7c and between the enlarged diameter portions 8a and 8a, respectively, with spacers 11 interposed therebetween, which are joined to each other by a plurality of tightening bolts 10a.

The bolt hole 9a of the guide bolt 10b is formed as a long hole long in the bridge axis direction. Further, wide clearance Lt and Lc are provided between the enlarged diameter portions 8a and 8a and the spacer 11 and between the enlarged diameter portions 8a and 7b, respectively, in the direction of the bridge axis.

In such a configuration, the large-scale seismic energy up to level 2 (the largest possible range) with respect to the load (tensile and compressive load) in the bridge axis direction acting between the joint portion 5 and the joint portion 6. With respect to seismic energy), the displacement core material 8 is displaced in the direction of the bridge axis with substantially no resistance in a state where the connection with the joint portion 5 is disconnected, and the length of the bolt hole 9a of the buckling restraining material 9 is obtained. Relative displacement in the direction of the bridge axis within the range of the hole (see Figures 8 (a), (b), (c), Figures 9 and 10). The reference numerals Lt and Lc indicate the gaps in which the displacement core material 8 can be displaced without any resistance.

As a result, tensile and compressive loads are not transmitted between the bridge girder 1 and the abutment 2, and large-scale seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 can be absorbed (Fig. 10). Load-displacement design curve (1)-(2)-(2)'see).

Further, in response to an unexpected seismic energy (major earthquake) exceeding level 2, the displacement core material 8 is displaced relative to the buckling restraining material 9 in the joint portion 5 direction with respect to a compressive load, and the displacement core material 8 is displaced. The end of the enlarged diameter portion 8a touches the end of the enlarged diameter portion 7b of the second deformed core material 7B (see FIG. 8 (c)).

Then, the compressive load is transmitted between the joint portion 5 and the joint portion 6, that is, between the end portion of the bridge girder 1 and the abutment 2 via the displacement core material 8, the second deformable core material 7B, and the buckling restraining material 9. 2 Deformation core material 7B is elastically or plastically deformed in the compression direction of the bridge axis (Fig. 8 (d), (e), load-displacement design curve (2)'-(3)'-(4) in Fig. 9 and 10. See'-(5)'). This makes it possible to absorb unexpected seismic energy (compressive load) exceeding level 2.

At that time, since a plurality of buckling restraining materials 9 are installed outside the first deformed core material 7A and the displacement core material 8, the first deformed core material 7A and the displacement core material 8 are seated under a compressive load. Never give in. Further, since the buckling restraining rib 7f is formed on the upper and lower surfaces of the connecting portion 7d, the connecting portion 7d also does not buckle due to the compressive load.

On the other hand, with respect to the tensile load, the first deformed core material 7A undergoes elasto-plastic deformation in the bridge axis tensile direction (load-displacement design curves (2) in FIGS. 8 (f), (g), 9 and 10). -(3)-(4)), the connecting portion 7d of the first deformed core material 7A is elastically or plastically deformed as the tensile load increases (load-displacement design curves (4)-(5) in FIGS. 9 and 10). reference). This makes it possible to absorb unexpected seismic energy (tensile load) exceeding level 2. In addition, when the tensile load reaches Pmax, the connecting portion 7d breaks (see Fig. 8 (h), load-displacement design curve in Fig. 9 and 10 (see (5)), resulting in fatal damage. Can be prevented in advance.

The connecting portion 7d can be systematically broken at the fracture-inducing recess 7e when the tensile load acting between the joint portions 5 and 6 in the bridge axial direction exceeds a preset load.

[Embodiment 2]
11 and 12 illustrate a second embodiment of the present invention. In the figure, each buckling restraining material 9 is approximately in the middle of the displacement core material 8, and is divided into buckling restraining material units (hereinafter referred to as “units”) 9A and 9B in the bridge axis direction, and the units 9A and 9B are rod-shaped. The structure is different from that of the bridge collapse prevention material of the first embodiment in that the structure is connected by the stopper 12. With such a configuration, the displacement core material 8 can also function as a plastically deformed core material against unexpected seismic energy acting between the joint portions 5 and 6.

More specifically, each buckling restraining material 9 is formed of two units, a unit 9A on the joint portion 5 side and a unit 9B on the joint portion 6 side, with the substantially intermediate portion of the displacement core material 8 as a boundary. Each unit 9A is joined to the side surface of the enlarged diameter portions 7a and 7c of the first and second deformed core materials 7A and 7B by a plurality of tightening bolts 10a and guide bolts 10b, and between the enlarged diameter portions 7a and 7c and expanded. A spacer 11 is interposed between the diameter portions 7b and 7c, and the spacers 11 are joined to each other by a plurality of tightening bolts 10a.

The unit 9B is joined to the side surface of the enlarged diameter portion 8a located on the joint portion 6 side of the displacement core material 8 by a guide bolt 10b, and a spacer 11 is interposed between the enlarged diameter portions 8a and 8a to accommodate a plurality of tightening bolts 10a. Joined to each other by.

The rod-shaped stopper 12 is a control member for controlling the separation distance between the units 9A and 9B, and is installed on the outside of each unit 9A and the unit 9B in the direction perpendicular to the axis direction substantially parallel to the bridge axis direction, and the unit 9A and the unit 9B. It is extended by a predetermined length in both directions of 9B.

The end portion 12b on the unit 9B side of each rod-shaped stopper 12 is fixed to the fixing rib 13 projecting from the side portion of the unit 9B, and the end portion 12a on the unit 9A side projects from the side portion of the unit 9A. A loose hole (not shown) formed in the fixing rib 14 is penetrated, and a retaining stopper 15 is attached to the tip portion 12a.

A long bolt is used for the rod-shaped stopper 12, and a nut is used for the retaining stopper 15. Further, by attaching a cushioning material such as rubber (not shown) to the retaining stopper 15, the cushioning effect can be enhanced when the separation between the units 9A and 9B is restricted.

In such a configuration, the displacement core material 8 is used for seismic energy up to level 2 with respect to the load (tensile and compressive load) in the bridge axis direction acting between the joint portion 5 and the joint portion 6. With the connection with the joint portion 5 disconnected, the displacement is substantially non-resistive in the direction of the bridge axis, and the displacement is relatively displaced in the direction of the bridge axis within the range of the elongated hole of the bolt hole 9a of the buckling restraining material 9 (FIG. 8 (a), (b), (c)).

As a result, tensile and compressive loads are not transmitted between the bridge girder 1 and the abutment 2, and seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 can be absorbed (Fig. 12). Load-displacement design curve (1)-(2)-see (2)').

Further, for unexpected seismic energy (major earthquake) exceeding level 2, the displacement core material 8 is displaced relative to the buckling restraining material 9 in the joint portion 5 direction with respect to the compressive load, and the diameter expansion portion 8a The end of the second deformed core material 7B touches the end of the enlarged diameter portion 7b (see FIG. 8 (c)).

Then, the compressive load is transmitted between the joint portion 5 and the joint portion 6, that is, between the end portion of the bridge girder 1 and the abutment 2 via the displacement core material 8, the second deformable core material 7B, and the buckling restraining material 9. 2 Deformation The core material 7B is elastically or plastically deformed in the compression direction of the bridge axis (see the load-displacement design curve (2)'-(3)'-(4)'-(5)'-(6)' in Fig. 12). ). This makes it possible to absorb unexpected seismic energy (compressive load) exceeding level 2.

On the other hand, with respect to the tensile load, the first deformed core material 7A undergoes elasto-plastic deformation in the bridge axis tensile direction (load-displacement design curve (2)-(3)-(4) in Fig. 12), and further. When the tensile load reaches the design load Py2 (load-displacement design curve (4)-(5) in FIG. 12), the displacement core material 8 yields and plastically deforms, which contributes to shock absorption. In addition, when the tensile load reaches the design maximum load Pmax, the connecting portion 7d on the joint portion 5 side breaks (see the load-displacement design curve (5)-(6) in Fig. 12), resulting in fatal damage. Can be prevented in advance.

When the relative displacement between the displacement core material 8 and the buckling restraining material 9 exceeds the range of the elongated hole of the bolt hole 9a, the tensile load in the bridge axial direction acting between the joint portion 5 and the joint portion 6 is determined. It is transmitted to the displacement core material 8 via the buckling restraining material 9. Further, since the rod-shaped stopper 12 is installed between the units 9A and 9B, the displacement core material 8 does not break before the connecting portion 7d of the first deformed core material 7A. However, it is possible to break the shaft portion of the rod-shaped stopper 12 by layering the yield strength as design control.

[Embodiment 3]
13 and 14 illustrate a third embodiment of the present invention. In the figure, each buckling restraining material 9 is approximately in the middle of the first deformed core material 7A, and is divided into buckling restraining material units (hereinafter referred to as “units”) 9A and 9B in the bridge axis direction, and the units 9A and 9B are divided into units 9A and 9B. The configuration is different from the bridge collapse prevention material of the first embodiment only in that the configuration is connected by the rod-shaped stopper 12.

More specifically, each buckling restraining material 9 is formed of two units, a unit 9A on the joint portion 5 side and a unit 9B on the joint portion 6 side, with the substantially intermediate portion of the first deformed core material 7A as a boundary. ..

Each unit 9A is joined to the side surface of the enlarged diameter portion 7a on the joint portion 5 side of the first deformed core material 7A by a plurality of tightening bolts 10a, and a spacer 11 is interposed between the enlarged diameter portions 7a and 7c. They are joined to each other by the tightening bolts 10a of.

Each unit 9B has a plurality of tightening bolts 10a on the side surface of the enlarged diameter portion 7c between the first and second deformed core materials 7A and 7B and on the side surface of the enlarged diameter portion 8a located on the joint portion 6 side of the displacement core material 8. The spacer 11 is interposed between the enlarged diameter portions 7b and 7c of the second deformed core material 7B and between the enlarged diameter portions 8a and 8a of the displacement core material 8 and is joined to each other by a plurality of tightening bolts 10a. It is joined. The bolt hole 9a of the guide bolt 10b is formed in a long hole having a long axis in the direction of the bridge axis.

The rod-shaped stopper 12 is a control member for controlling the separation distance between the units 9A and 9B, and is installed on the outside of each unit 9A and the unit 9B in the direction perpendicular to the axis direction substantially parallel to the bridge axis direction, and the unit 9A and the unit 9B. It is extended by a predetermined length in both directions of 9B.

The end portion 12b on the unit 9B side of each rod-shaped stopper 12 is fixed to the fixing rib 13 projecting from the side portion of the unit 9B, and the end portion 12a on the unit 9A side projects from the side portion of the unit 9A. A loose hole (not shown) formed in the fixing rib 14 is penetrated, and a retaining stopper 15 is attached to the tip portion 12a thereof.

A long bolt is used for the rod-shaped stopper 12, and a nut is used for the retaining stopper 15. Further, by attaching a cushioning material such as rubber (not shown) to the retaining stopper 15, the cushioning effect can be enhanced when the displacement is limited.

In such a configuration, the displacement core material 8 is used for seismic energy up to level 2 with respect to the load (tensile and compressive load) in the bridge axis direction acting between the joint portion 5 and the joint portion 6. With the connection with the joint portion 5 disconnected, the displacement is substantially non-resistive in the direction of the bridge axis, and the displacement is relatively displaced in the direction of the bridge axis within the range of the elongated hole of the bolt hole 9a of the buckling restraining material 9 (FIG. 8 (a), (b), (c)).

As a result, tensile and compressive loads are not transmitted between the bridge girder 1 and the abutment 2, and seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 can be absorbed (Fig. 14). Load-displacement design curve (1)-(2)-see (2)').

Further, in response to an unexpected seismic energy (major earthquake) exceeding level 2, the displacement core material 8 is displaced relative to the buckling restraining material 9 in the joint portion 5 direction with respect to a compressive load, and the displacement core material 8 is displaced. The end of the enlarged diameter portion 8a touches the end of the enlarged diameter portion 7b of the second deformed core material 7B (see FIG. 8 (c)).

Then, the compressive load is transmitted between the joint portion 5 and the joint portion 6, that is, between the end portion of the bridge girder 1 and the abutment 2 via the displacement core material 8, the second deformable core material 7B, and the buckling restraining material 9. As a result, the second deformed core material 7B is elastically or plastically deformed in the compression direction of the bridge axis (see the load-displacement design curve (2)'-(3)'-(4)'-(5)' in FIG. 14).

On the other hand, with respect to the tensile load, the first deformed core material 7A and the displacement core material 8 are elasto-plastically deformed in the bridge axis tensile direction (load-displacement design curve (2)-(3)-(4) in FIG. 14). (See), and when the separation distance between the units 9A and 9B is controlled by displacement, the load rises, and when the maximum design load Pmax is finally reached, the connecting part 7d on the joint part 5 side breaks (Fig.). 14 Load-Displacement Design Curves (4)-(5)), can prevent fatal damage.

When the relative displacement between the displacement core material 8 and the buckling restraining material 9 exceeds the range of the elongated hole of the bolt hole 9a, the tensile load in the bridge axial direction acting between the joint portion 5 and the joint portion 6 is determined. It is transmitted to the displacement core material 8 via the buckling restraining material 9. Further, since the rod-shaped stopper 12 is installed between the units 9A and 9B, the first deformable core material 7A does not break before the connecting portion 7d.

[Embodiment 4]
15 and 16 are the fourth embodiments of the present invention. In the figure, the first modified core material 7A is provided with a damper function by setting a wide elasto-plastic deformation region in place of the deformed core material 16 instead of the displacement core material 8. It is different from the bridge collapse prevention material.

More specifically, the first deformed core material 7A is formed to be longer than the second deformed core material 7B and the deformed core material 16, whereby the elasto-plastic deformation region of the first deformed core material 7A becomes wider, and the joint portion 5 It has a damper function that attenuates the seismic energy that acts between and 6. Other than that, it is basically formed in the same shape as the first deformable core material 7A.

Further, the deformed core material 16 is formed in a substantially cross-shaped cross section that is elongated and continuous in the bridge axis direction, and enlarged diameter portions 16a and 16a are formed at both ends in the bridge axis direction, and basically the displacement core material 8 is formed. It is formed in almost the same shape as.

Further, the deformed core material 16 is installed adjacent to the second deformed core material 7B on the joint portion 6 side of the second deformed core material 7B, and is joined at the end portion on the joint portion 6 side with the same width as the enlarged diameter portion 16a. A flat plate-shaped connecting portion 16b extending to the portion 6 side is formed, and the connecting portion 16b is rotatably connected to the joint portion 6.

Further, it is formed so as not to yield and break before the connecting portion 7d of the first deformed core material 7A with respect to the tensile load in the bridge axis direction acting between the joint portion 5 and the joint portion 6, for example, from the connecting portion 7d. It is formed to have a large cross-sectional diameter or is made of ordinary steel (eg, SM400) (see FIG. 19).

It is desirable to select or combine these members as appropriate according to the required performance of the design. For example, even if the same steel material is used, the yield stress and elongation performance of the steel material can be improved with ordinary steel, low yield point steel, and shape memory alloy. There is a difference (see Figure 18). In addition, when receiving repeated low strains, it is desirable to select based on the degree of cumulative damage.

Further, by layering the strength of these member cross sections, it is possible to design and control the order of plasticization. For example, when the same steel material is selected, the cross-sectional area of the first deformed core material 7A is the smallest, followed by the deformed core material 16 and the connecting portion 7d of the first deformed core material 7A, in that order, and the connecting portion 16b. By forming the members so as to have the largest cross-sectional area, these members can be elasto-plastically deformed in this order.

In such a configuration, for seismic energy up to level 2, the first deformed core material is subjected to the axial force (tensile and compressive load) in the bridge axial direction acting between the joint portion 5 and the joint portion 6. 7A undergoes elasto-plastic deformation (see Load-Displacement Design Curve (1)-(2)-(3) (4)-(5)-(6)-(7) in Fig. 16). As a result, it is possible to absorb a large-scale seismic energy up to level 2 acting between the joint portion 5 and the joint portion 6.

Further, for unexpected seismic energy exceeding level 2, the deformed core material 16 is displaced relative to the buckling restraining material 9 in the joint portion 5 direction within the range of the elongated hole of the bolt hole 9a with respect to the compressive load. As a result, the end of the enlarged diameter portion 16a of the deformed core material 16 touches the end of the enlarged diameter portion 7b of the second deformed core material 7B (see FIG. 8 (c)).

Then, the compressive load is transmitted between the joint portion 5 and the joint portion 6, that is, between the end portion of the bridge girder 1 and the abutment base 2 via the deformable core material 16, the second deformable core material 7B, and the buckling restraining material 9. 2 Deformation The core material 7B is elastically or plastically deformed in the compression direction of the bridge axis (see the load-displacement design curve (8)'-(9)'-(10)' in Fig. 16). This makes it possible to absorb unexpected seismic energy (compressive load) exceeding level 2.

On the other hand, with respect to the tensile load, the deformed core material 16 elastically deforms in the bridge axis tensile direction within the range of the elongated hole 16a (see the load-displacement design curve (3)-(8)-(9) in Fig. 16). ), Further, the connecting portion 7d of the first deformed core material 7A is elastically or plastically deformed (see the load-displacement design curve (9)-(10) in FIG. 16). This makes it possible to absorb unexpected seismic energy (tensile load) exceeding level 2. Further, when the tensile load reaches Pmax, the connecting portion 7d breaks, so that it is possible to prevent fatal damage from occurring.

When the elasto-plastic deformation of the first deformed core material 7A exceeds the range of the bolt hole 9a , the tensile load acting between the joint portion 5 and the joint portion 6 is applied to the deformed core material 16 via the buckling restraining material 9. Is transmitted to.

[Embodiment 5]
FIG. 17 is a fifth embodiment of the present invention. In the fourth embodiment, each buckling restraining material 9 is placed at a substantially intermediate portion of the deformed core material 16 and two buckling restraining units are provided in the bridge axial direction. It is a design example in the case where each unit is connected to each other by a rod-shaped stopper that controls the separation between the units, and the load-displacement design curve is shown.

[Embodiment 6]
FIG. 18 is a sixth embodiment of the present invention. In the fourth embodiment, the displacement core material 8 in the first embodiment is installed in place of the deformed core material 16, so that the displacement core material 8 is displaced in the axial direction without resistance. This is a design example when the clearance area is set, and the load-displacement design curve is shown.

The present invention has extremely large deformation capacity and energy absorption capacity for loads in both tensile and compressive directions during an earthquake, and is not only for the largest possible earthquake (level 2 seismic motion) but also for level 2 earthquakes. It can respond to unexpected large earthquakes that exceed the range, and can be used as a bridge collapse prevention material installed between the end of the bridge girder and the abutment that supports the end of the bridge girder, for example.

1 End of bridge girder 2 Abutment 3 Collapse prevention material (function separation type shock absorber)
4 Bearings 5 Fittings 6 Fittings
7A 1st deformable core material (axially deformable member)
7B 2nd deformable core material (axially deformable member)
7a Enlarged diameter part
7b Enlarged diameter part
7c Enlarged diameter part
7d connection
7e Break-inducing recess (break-inducing part)
7f Buckling restraint rib 8 Displacement core material (axial displacement member)
8a Enlarged diameter part
8b Connection 9 Buckling restraint
9A unit (buckling restraint unit)
9B unit (buckling restraint unit)
9a bolt holes
10a tightening bolt
10b guide bolt
11 Spacer
12 Rod stopper
13 Fixing rib
14 Fixing ribs
15 Retaining stopper
16 Deformed core material (axially deforming member)
16a Enlarged diameter part
16b Connection
17 Telescopic device

Claims (7)

The deformed core material as an energy absorbing material has joints with enlarged cross sections at both ends in the axial direction, and the deformed core material excluding the joints is sandwiched between buckling restraining materials from all sides to form the deformed core material. The deformed core material and the buckling restraining material are joined by a tightening bolt penetrating in the direction perpendicular to the material axis to restrain the relative movement in the material axis direction, and the buckling. The elongated hole formed in the restraining material is joined by a guide bolt penetrating in the direction perpendicular to the material axis, and is provided with a movable portion that allows relative movement in the material axis direction within the range of the length of the elongated hole. In a rod-shaped shock absorber that expands and contracts in the direction of the material axis in response to the tensile and compressive loads acting between the joints.
The first displacement section on the tension side is configured so that the displacement is constrained at the preset upper limit displacement while being elasto-plastically deformed on the same material axis of the deformed core material by receiving a tensile load in the material axis direction. And, in a state where the displacement in the first displacement section on the tension side is constrained by the displacement of the set upper limit, the second displacement on the tension side undergoes elastic deformation or elasto-plastic deformation by receiving a tensile load in the material axial direction. Set the displacement section and the displacement section on the compression side that undergoes elasto-plastic deformation by receiving a compressive load in the material axis direction.
At one end of the first displacement section on the pulling side, a fixing portion is formed by being joined to the buckling restraining material by a tightening bolt penetrating in the direction perpendicular to the material axis to restrain the relative movement in the material axis direction, and at the other end. Is joined by a guide bolt penetrating the long hole formed in the buckling restraining material in the direction perpendicular to the material axis, and the long hole is allowed to move relative to the material axis within the range of the length of the long hole. A movable part is formed at the end where the displacement in the material axis direction is constrained.
At one end of the second displacement section on the pulling side, a fixing portion is formed by being joined to the buckling restraining material by a tightening bolt penetrating in the direction perpendicular to the material axis to restrain the relative movement in the material axis direction, and at the other end. Is formed with a movable part that allows relative movement in the material axis direction.
One end of the displacement section on the compression side is joined to the buckling restraining material by a tightening bolt penetrating in the direction perpendicular to the material axis to form a fixing portion that restrains the relative movement in the material axis direction, and the other end is the material shaft. A movable part that allows relative movement in the direction is formed,
A function-separated shock absorber characterized by being In the function-separated type shock absorber according to claim 1 , the second displacement section of the deformed core material is configured to be elastically deformed by receiving a tensile load, and the displacement is constrained at a preset upper limit displacement. And, in a state where the second displacement section is constrained by the preset upper limit displacement, the third displacement section on the tension side which is elastically deformed or elasto-plastically deformed by receiving a tensile load in the material axial direction is described above. A function-separated shock absorber characterized by being provided on the same material axis of the deformed core material . In the function-separated type impact absorber according to claim 1 or 2, the displacement core material constituting the impact absorber is substantially disconnected from one of the joint portions by receiving a tensile and compressive load. A function-separated impact absorbing device characterized in that a displacement section set as a clearance region that is displaced in the axial tension direction and the axial compression direction without resistance is provided on the same material axis of the deformed core material . In the function-separated impact absorbing device according to any one of claims 1 to 3, a fracture-inducing portion that breaks with a set tensile load in the first, second, or third displacement sections of the deformed core material. A function-separated shock absorber characterized by being provided with. In the function-separated shock absorber according to any one of claims 1 to 4, a shape memory alloy or a low yield point steel is used as a material for the first, second and / or third displacement sections of the deformed core material. A function-separated shock absorber characterized by being used. The function-separated shock absorber according to any one of claims 1 to 5 is interposed between the substructure and the superstructure of the bridge having a structure that allows the destruction of the bearing due to a ground motion of level 2 or higher. A bridge equipped with a function-separated shock absorber. In the bridge provided with the function-separated shock absorber according to claim 6, the function-separated shock absorber is destroyed by a ground motion of level 2 or higher and a ground motion equal to or less than the ground motion destroyed by the bearing. A bridge provided with a function-separated shock absorber, characterized in that the displacement section of the deformed core material is set to allow it.

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