JP6872359B2 - Shock absorber - Google Patents

Description

The present invention relates to a shock absorber having enhanced deformation capacity and energy absorption capacity in the material axis direction with respect to a conventional rod-shaped vibration damping member. For example, between an end of a bridge girder and an abutment supporting the end of the bridge girder. It can be installed in and used as a shock absorbing member in the event 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, Patent Document 3 describes a shaft yield type elasto-plastic history in which the outer periphery of a steel core material is covered with a buckling restraining concrete member via an unbonded layer, and the outer periphery of the buckling restraining concrete member is covered with a steel pipe to reinforce it. Brace improvement technology is described.

FIG. 19 shows 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 to prevent the core material 30 body from buckling.

In this example, the core material 30 and the deformation restraint member 33 are formed by 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. 19 (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 an 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 an axial compressive force acts on the core material 30, the core material 30 stretches in the elastic range or the elastic range. It shrinks in the elasto-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. The energy absorption capacity as a member can be fully exhibited.

FIG. 20 shows 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 has a configuration and operation other than the point where the cross section of the core material 30 body is a cross section. The effect is the same as in the case of the flat plate of FIG. 17, but when the same deformation occurs, the core material 30 has a higher energy absorption capacity due to the larger cross section.

By the way, in bridges such as road bridges, the length of the girder is sufficient on the substructure side so that the end of the bridge girder, which is the superstructure, does not fall 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 substructure are connected with a bridge collapse prevention material.

In recent years, studies have been made to make the rod-shaped damping member also function as a bridge collapse prevention material, 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 damping members, the core material is always shaft yielded to absorb seismic energy by historical damping in the event of a large-scale earthquake, but design support that takes into account unexpected earthquakes is also required. Sometimes.

For example, when used by attaching it between a bridge girder and an abutment that supports the bridge girder, if the core material of the rod-shaped 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.

In addition, when designing mainly the bridge collapse prevention material, it is not necessary to plastically deform the core material until the function of the bearing is lost as a bridge collapse prevention system, and during that time, a structure that can follow the deformation of the bearing is required. Will be done. In other words, if the function of the bearing is lost due to unexpected seismic behavior, the core material should be axially yielded and plastically deformed, and the timing of designing the core material to be axially yielded differs depending on the purpose of use. It is.

The present invention has been made in view of such circumstances, and has extremely high deformation capacity and energy absorption capacity at the time of an earthquake, and only for the largest earthquake (level 2 seismic motion) within the conceivable range. It is possible to respond to unexpected large earthquakes beyond the range of level 2, for example, a shock absorber suitable 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. Is intended to provide.

The present invention is an invention of a rod-shaped shock absorbing device having joint portions at both ends in the material axial direction and expanding and contracting in the material axial direction, and in the first displacement section set as a plastic deformation region, the shock absorbing device. The first axially deforming member constituting the above is elastically or plastically deformed to the extent that it does not break, and the displacement is constrained at the upper limit of the first displacement section. In the second displacement section, which is set as the second plastic deformation region, the specific second axially deforming member constituting the shock absorbing device is elastically deformed or plastically deformed. Is.

In the third displacement section where the second axially deforming member exceeds the second displacement section and is set as the third plastic deformation region, a specific third axially deforming member constituting the shock absorbing device is used. It can also be configured to be elastically deformed or plastically deformed.

Further, a displacement section in which a specific axial displacement member constituting the shock absorbing device is set as a clearance region in which the specific axial displacement member is displaced in the axial direction with substantially no resistance in a state where the connection with one of the joint portions is disconnected. It can also be provided. Further, as the material of the axially deformable member, a low yield point steel or a shape memory alloy having excellent deformability can be used in addition to the ordinary steel which is a JIS material, depending on the required performance.

The shock absorber of the present invention can be installed between the substructure and the superstructure of a bridge having a structure that allows the destruction of bearings in a ground motion of level 2 or higher, and further by a ground motion of level 2 or higher. Even if one core material is destroyed, 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.

In the shock absorbing device of the present invention, by separating the core material serving as the absorbing material of the shock absorbing device of the rod-shaped vibration damping member into two, the functions of each can be clarified and the yield load of the core material can be layered. In addition, it is possible to provide a clearance length between the separated core materials, and the structure is capable of adding deformation followability with respect to normal times. In addition, as a bridge collapse prevention structure, it is possible to absorb shock even with a compressive force that cannot be handled by the conventional cable type.

The first embodiment of the shock absorber of the present invention is illustrated. FIG. 1 (a) shows an initial state, FIG. 1 (b) shows a tensile force acting on the core material on the left side after shaft yielding and then plasticity. FIG. 1 (c) is a perspective view of the final fractured state when the joint portion is tentatively destroyed. 2 (a) and 2 (b) are cross-sectional views taken along the line 1 (a) and FIG. 11 (a), respectively. It is the figure which illustrated the installation example of the shock absorbing device of this invention, and is the side view of the shock absorbing device installed between the bridge girder end portion and an abutment. It is a side view which shows the tensile deformation in the operating state of the shock absorbing device 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 shock absorbing device of this invention installed between the bridge girder end part and an abutment. It is a graph which shows the load-displacement design curve when an axial force (compression and tension force) acted on the shock 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. A second embodiment of the shock absorber of the present invention is illustrated. FIG. 7 (a) shows an initial state, and FIG. 7 (b) shows a tensile force acting on the left core material to yield and operate. FIG. 7 (c) is a perspective view of the final fractured state when the core material on the right side is then plastically deformed after the shaft yields and the joint portion is fractured. It is a graph which shows the load-displacement design curve when an axial force (compression and tension force) acted on the shock absorber of FIG. 7. This is an example of a design in which the divided core materials are subjected to plastic deformation after each shaft yields due to the layering of the yield load and then fractures at the maximum design load. A third embodiment of the shock absorber of the present invention is illustrated. FIG. 9 (a) shows an initial state, and FIG. 9 (b) shows a tensile force acting on the left core material to yield and operate. It is a perspective view of the state. FIG. 5 is a graph showing a load-displacement design curve when an axial force (compression and tensile force) is applied to the shock absorber of FIG. 9. A fourth embodiment of the shock absorbing device of the present invention is illustrated. FIG. 11A shows the initial state, and FIG. 11B shows the left core material repeatedly compressing and tensioning after the shaft yields. After that, it is a perspective view of an operating state in which the tensile load reaches the yield load of the core material on the right side and plastically deforms. It is a graph which shows the load-displacement design curve when an axial force (compression and tension force) are applied to the shock absorber of FIG. A fifth embodiment of the shock absorber of the present invention is illustrated. FIG. 13 (a) shows an initial state, and FIG. 13 (b) shows a repeated displacement of compression / tension after the core material on the left side yields to the shaft. 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 plastically deforms after repeating. It is a graph which shows the load-displacement design curve when an axial force (compression and tension force) are applied to the shock absorber of FIG. A fifth embodiment of the shock absorber of the present invention is illustrated. FIG. 15 (a) shows an initial state, and FIG. 15 (b) shows a core material after shaft yielding and repeated compression / tensile displacements. It is a perspective view of the operating state in which the tensile displacement reaches the set displacement and is further plastically deformed. It is a graph which shows the load-displacement design curve when an axial force (compression and tension force) are applied to the shock absorber of FIG. It is a graph which shows the load-displacement design curve when an axial force (compression and tension force) acted on the shock absorber of the 7th Embodiment of the shock absorber of this invention. This is a design example in the case where a play area that is displaced in the axial direction without resistance is set in the fourth embodiment. It is a graph which shows the stress-strain curve of a typical steel material used as a core material in the shock absorber of this invention. (a) is a partially transparent perspective view showing an example (in the case of a flat plate core material) of a buckling restraint brace as a conventional rod-shaped vibration damping member, and (b) is a cross-sectional view in the direction perpendicular to the axis. (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 damping member, and (b) is a cross-sectional view in the direction perpendicular to the axis.

[Embodiment 1]
1 to 6 are the first embodiment of the present invention, and show a bridge collapse prevention material and an installation example thereof. In the figure, the bridge collapse prevention material 3 and the bearing 4 are attached between the end of the bridge girder 1 and the abutment 2 supporting the end of the bridge girder 1. In each case, a plurality of bridge girders 1 are attached at intervals in the width direction. Reference numeral 17 is a telescopic device.

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

_{Further, a first displacement section L 1} and a second displacement section L ₂ set as elasto-plastic deformation regions between the joint portion 5 and the joint portion 6 are provided adjacent to the bridge collapse prevention material 3 in the material axial direction. Has been done.

More specifically, the first and second displacement sections L ₁ and L ₂ are described. The deformed core material 7 and the displacement core material 8 are adjacent to each other in the material axis direction on the same material axis between the joint portion 5 and the joint portion 6. A plurality of buckling restraint members 9 are arranged outside the deformed core member 7 and the displacement core member 8 in the direction perpendicular to the axis.

The deformed core material 7 is formed in the shape of an elongated long plate between the joint portion 5 and the joint portion 6 in the material axial direction, and has a side view arrow blade shape and a cross section at both ends of the deformed core material 7 in the material axial direction. Expanded diameter portions 7a and 7a forming a cross shape are formed. Further, a flat plate-shaped connecting portion 7b having the same width as the enlarged diameter portion 7a and projecting to the joint portion 5 side is formed at the end portion on the joint portion 5 side, and the connecting portion 7b is rotatably connected to the joint portion 5. ..

The displacement core material 8 is adjacent to the deformed core material 7 on the joint portion 6 side, and is connected to the joint portion 5 with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. Is arranged so as to be displaced in the direction of the material axis with substantially no resistance in a separated state.

The displacement core material 8 will be described in more detail. The displacement core material 8 is formed to be long in the material axis direction between the joint portion 5 and the joint portion 6 and has a substantially cross-shaped cross section. Further, enlarged diameter portions 8a and 8a having a side view arrow blade shape and a cross-sectional cross shape are formed at both ends of the displacement core material 8 in the material axial direction.

Further, a flat plate-shaped connecting portion 8b having the same width as the enlarged diameter portion 8a and projecting to the joint portion 6 side is formed at the end portion of the displacement core material 8 on the joint portion 6 side, and the connecting portion 8b can rotate to the joint portion 6. Is connected to. Further, a clearance W having a constant length in the material axial direction between the joint portion 5 and the joint portion 6 is provided between the enlarged diameter portions 8a and 8a and the spacer 11 interposed between the enlarged diameter portions 8a and 8a.

Further, the cross-sectional area between the enlarged diameter portions 7a and 7a is formed to be smaller than that of the connecting portion 7b so that the diameter-expanded portions 7a and 7a of the deformed core material 7 are elastically deformed or plastically deformed before the connecting portion 7b. Further, the deformed core material 7 is formed of low yield point steel (for example, LY225 standard, etc.), and the displacement core material 8 is formed of ordinary steel (for example, SM400) (see FIG. 18).

The buckling restraining material 9 is continuous in the material axis direction of the deformed core material 7 and the displacement core material 8, has a length substantially equal to the total length of the deformed core material 7 and the displacement core material 8, and has a substantially equilateral cross section. It is formed in a shape. Further, the deformed core material 7 and the displacement core material 8 are arranged so as to sandwich the deformed core material 7 and the displacement core material 8 from all sides on the outside in the direction perpendicular to the axis of the deformed core material 7 and the displacement core material 8.

Further, each buckling restraining member 9 is joined to each side surface of the enlarged diameter portions 7a and 7a of the deformed core material 7 and the enlarged diameter portions 8a and 8a of the displacement core material 8 by a plurality of tightening bolts 10a and guide bolts 10b. In addition, spacers 11 are interposed between the enlarged diameter portions 7a and 7a and between the enlarged diameter portions 8a and 8a, and are joined to each other by a plurality of tightening bolts 10a and guide bolts 10b. Further, the bolt holes 9a of the guide bolts 10b formed at both ends of each buckling restraining member 9 in the material axial direction are formed into elongated holes having a long axis in the material axial direction of the buckling restraining member 9.

In such a configuration, the displacement core material 8 and the buckling restraining material 9 are in the range of the elongated holes of the bolt holes 9a with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. Relative displacement in the material axis direction. As a result, it is possible to absorb seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 (the largest earthquake within the conceivable range) (load-displacement design curve in FIG. 6 (Fig. 6). 1)-(2)-(3)). In addition, in the event of an unexpected large earthquake exceeding level 2, the deformed core material 7 undergoes elasto-plastic deformation in the material axis direction (load-displacement design curve (3)-(4)-(5) in FIG. 6), and further. The connecting portion 7b on the joint portion 5 side of the deformed core material 7 is elastically or plastically deformed (load-displacement design curve (5)-(6) in FIG. 6).

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 axial force acting between the joint portion 5 and the joint portion 6 is the buckling restraining material 9. It is transmitted to the displacement core material 7 via. Further, with respect to the compressive force acting between the joint portion 5 and the joint portion 6, the end portion of the enlarged diameter portion 8a of the displacement core material 8 touches the end portion of the enlarged diameter portion 7a of the deformed core material 7. As a result, the load is transmitted through the core materials of the deformed core material 7 and the displacement core material 8.

[Embodiment 2]
7 and 8 show a second embodiment of the present invention. In the figure, each buckling restraining material 9 is composed of two buckling restraining material units 9A and 9B in the material axial direction between the joint portion 5 and the joint portion 6, and each buckling restraining material 9 is formed. The configuration is different from the bridge collapse prevention material of the first embodiment in that the rod-shaped stopper 12 is attached to the outside of the material units 9A and 9B.

By dividing the buckling restraining material 9 into 9A and 9B, the displacement core material 8 can function as a plastic deformed core material in the event of an unexpected earthquake.

To explain in detail, each buckling restraining material 9 consists of two buckling restraining material units 9A on the joint portion 5 side and a buckling restraining material unit 9B on the joint portion 6 side with the substantially intermediate portion of the displacement core material 8 as a boundary. It is composed of a buckling restraint unit.

Each buckling restraint unit 9A is joined to the side surface portions of the enlarged diameter portions 7a and 7a of the deformed core material 7 by a plurality of tightening bolts 10a and guide bolts 10b, and a spacer 11 is provided between the enlarged diameter portions 7a and 7a. It is intervened and joined to each other by a plurality of guide bolts 10b.

Further, the buckling restraining material unit 9B is joined to the side surface portion of the enlarged diameter portion 8a located on the joint portion 6 side of the displacement core material 8 by the guide bolt 10b, and further, the buckling restraining material units 9A are joined to each other and the seat. The bending restraint unit 9B is joined by a plurality of tightening bolts 10a and guide bolts 10b with a spacer 11 interposed between the enlarged diameter portions 8a and 8a of the displacement core material 8.

The rod-shaped stopper 12 is a stopper material for controlling the separation distance between the buckling restraining material units 9A and 9B, and it can be expected that the impact interference effect will be further enhanced if an interfering material is interposed when the displacement is limited. The buckling restraint units 9A and 9B are arranged outside the buckling restraint unit 9A and the buckling restraint unit 9B in the direction perpendicular to the axis, and along the material axial direction of the buckling restraint unit 9A and 9B. It is extended by a predetermined length almost symmetrically in both directions.

Further, the end portion 12b of the rod-shaped stopper 12 on the buckling restraint unit 9B side is fixed to the fixing rib 13 projecting from the side of the buckling restraint unit 9B, and is fixed to the buckling restraint unit 9A side. The end portion 12a penetrates a loose hole formed in a fixing rib 14 projecting from the side portion of the buckling restraint unit 9A, 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.

In such a configuration, the displacement core material 8 and the buckling restraining material 9 are in the range of the elongated holes of the bolt holes 9a with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. Relative displacement in the material axis direction. As a result, it is possible to absorb seismic energy up to level 2 (the largest earthquake within the conceivable range) acting between the end of the bridge girder 1 and the abutment 2 (load-displacement design curve in FIG. 8 (FIG. 8). 1)-(2)-(3)).

Further, in the event of an unexpected large earthquake exceeding level 2, the deformed core material 7 undergoes elasto-plastic deformation (load-displacement design curve (3)-(4)-(5) in FIG. 8) in the material axis direction, and is further set. When the load Py2 is reached, the displacement core material 8 yields on the shaft and contributes to shock absorption by plastically deforming, and when the maximum design load Pmax is finally reached, the connecting portion 7b on the joint portion 5 side breaks (Fig. Load-displacement design curve of 8 (5)-(6)-(7)).

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 axial force acting between the joint portion 5 and the joint portion 6 is the buckling restraining material 9. It is transmitted to the displacement core material 7 via. Further, since the rod-shaped stopper 12 is arranged between the buckling restraining material units 9A and 9B, the displacement core material 8 does not break before the connecting portion 7b of the deformed core material 7. However, it is possible to break the shaft portion of the rod-shaped stopper 12 by layering the yield strength as design control.

Further, with respect to the compressive force acting between the joint portion 5 and the joint portion 6, the end portion of the diameter-expanded portion 8a of the displacement core material 8 touches the end portion of the diameter-expanded portion 7a of the deformed core material 7. As a result, the load is transmitted through the core materials of the deformed core material 7 and the displacement core material 8.

[Embodiment 3]
9 and 10 illustrate a third embodiment of the present invention. In the figure, each buckling restraining material 9 is composed of two buckling restraining material units 9A and 9B in the material axial direction between the joint portion 5 and the joint portion 6, and each buckling restraining material unit 9A and 9B. The structure is different from the bridge collapse prevention material of the first embodiment in that the rod-shaped stopper 12 is attached to the outside.

To explain in detail, each buckling restraining material 9 consists of two buckling restraining material units 9A on the joint portion 5 side and a buckling restraining material unit 9B on the joint portion 6 side with the substantially intermediate portion of the deformed core material 7 as a boundary. It is composed of a buckling restraint unit.

Each buckling restraint unit 9A is joined to the side surface portions of the enlarged diameter portions 7a and 7a of the deformed core material 7 by a plurality of tightening bolts 10a, and is joined to each other by a plurality of tightening bolts 10a via a spacer 11. There is.

A plurality of buckling restraint unit 9Bs are provided on the side surface of the enlarged diameter portion 7a located on the joint portion 6 side of the deformed core material 7 and on the side surface portion of the enlarged diameter portion 8a located on the joint portion 6 side of the displacement core material 8. It is joined by the guide bolts 10b of the above, and further, a spacer 11 is interposed between the enlarged diameter portions 8a and 8a of the displacement core member 8 and is joined to each other by a plurality of tightening bolts 10a. In particular, the bolt holes 9a formed at the end of each buckling restraint unit 9B on the joint portion 6 side are formed into elongated holes having a long axis in the material axis direction of the buckling restraint unit 9B.

The rod-shaped stopper 12 is a stopper material for controlling the separation distance between the buckling restraint unit 9A and 9B, and is arranged outside the buckling restraint unit 9A and the buckling restraint unit 9B in the direction perpendicular to the axis. In addition, along the material axial direction of the buckling restraint unit 9A and 9B, the buckling restraint unit 9A and 9B are extended by a predetermined length substantially symmetrically in both directions.

Further, the end portion 12b of the rod-shaped stopper 12 on the buckling restraint unit 9B side is fixed to the fixing rib 13 projecting from the side of the buckling restraint unit 9B, and is fixed to the buckling restraint unit 9A side. The end portion 12a penetrates a loose hole formed in a fixing rib 14 projecting from the side portion of the buckling restraint unit 9A, and a retaining stopper 15 is attached to the tip portion 12a thereof.

In such a configuration, the displacement core material 8 and the buckling restraining material 9 are in the range of the elongated holes of the bolt holes 9a with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. Relative displacement in the material axis direction. This makes it possible to absorb large-scale seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 (load-displacement design curve (1)-(2)-(3) in Fig. 10). ..

Further, in the event of an unexpected large earthquake exceeding level 2, the deformed core material 7 and the displacement core material 8 are elasto-plastically deformed in the material axial direction (load-displacement design curve (3)-(4)-(5) in FIG. 10). ) Further, when the separation distance between the buckling restraint unit 9A and 9B is displacement-controlled, the load rises, and when the design maximum load Pmax is finally reached, the connecting portion 7b on the joint portion 5 side breaks. (Load-displacement design curve (5)-(6) in Fig. 10).

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 axial force acting between the joint portion 5 and the joint portion 6 is the buckling restraining material 9. It is transmitted to the displacement core material 7 via. Further, since the rod-shaped stopper 12 is arranged between the buckling restraining material units 9A and 9B, the deformed core material 7 does not break before the connecting portion 7b of the deformed core material 7.

Further, with respect to the compressive force acting between the joint portion 5 and the joint portion 6, the end portion of the diameter-expanded portion 8a of the displacement core material 8 touches the end portion of the diameter-expanded portion 7a of the deformed core material 7. As a result, the load is transmitted through the core materials of the deformed core material 7 and the displacement core material 8.

[Embodiment 4]
11 and 12 are the fourth embodiment of the present invention, in which the deformed core material 16 is replaced with the deformed core material 7 on the same material axis between the joint portion 5 and the joint portion 6. It is different from the bridge fall prevention materials of the first to third embodiments in that the function of the damper is imparted by being arranged adjacent to each other and setting the elasto-plastic region of the deformed core material 7 to be long.

More specifically, the first deformed core material 7 and the second deformed core material 16 are arranged adjacent to each other in the material axis direction on the same material axis between the joint portion 5 and the joint portion 6, and the deformed core material 16 is deformed. It is arranged on the joint portion 6 side of the core material 7.

The deformed core material 7 is formed in the shape of an elongated long plate between the joint portion 5 and the joint portion 6 in the material axial direction, and has an expanded side view arrow blade shape and a cross-sectional cross shape at both ends in the material axial direction. The diameters 7a and 7a are formed. Further, a flat plate-shaped connecting portion 7b having the same width as the enlarged diameter portion 7a and projecting to the joint portion 5 side is formed at the end portion on the joint portion 5 side, and the connecting portion 7b is rotatably connected to the joint portion 5. ..

The second deformed core member 16 is formed to be long in the material axial direction between the joint portion 5 and the joint portion 6, and is formed in a substantially cross-shaped cross section. Further, enlarged diameter portions 16a and 16a having a side view arrow blade shape and a cross-sectional cross shape are formed at both ends of the deformed core material 16 in the material axial direction. Further, a flat plate-shaped connecting portion 16b having the same width as the enlarged diameter portion 16a and projecting to the joint portion 6 side is formed at the end portion of the deformed core material 16 on the joint portion 6 side, and the connecting portion 16b can rotate to the joint portion 6. Is connected to.

It is desirable that these members are appropriately selected or used in combination according to the required performance of the design. For example, even with the same steel material, there are differences in the yield stress and elongation performance of ordinary steel, low yield point steel, and shape memory alloy (see Fig. 18). For example, when receiving repeated low strains, it is desirable to select 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 deformed core material 7 is the smallest, followed by the deformed core material 16 and the connecting portion 7b of the deformed core material 7, and the cross-sectional area of the connecting portion 16b is larger. By forming so as to be the largest, these members can be plastically deformed in this order. Further, by lengthening the length of the deformed core material 7 and widening the elasto-plastic deformation region, it is possible to impart the function of a damper that attenuates the seismic motion acting between the joint portions 5 and 6.

The buckling restraining material 9 is continuous in the material axis direction of the deformed core material 7 and the deformed core material 16, has a length substantially equal to the total length of the deformed core material 7 and the deformed core material 16, and has a substantially equilateral cross section. It is formed in a shape. Further, the deformed core material 7 and the deformed core material 16 are arranged so as to sandwich the deformed core material 7 and the deformed core material 16 from all sides on the outside in the direction perpendicular to the axis.

Further, each buckling restraining member 9 has a plurality of guide bolts on the side surface portions of the enlarged diameter portions 7a and 7a of the deformed core material 7 and the side surface portions of the enlarged diameter portion 16a located on the joint portion 6 side of the deformed core material 16. It is joined by 10b, and a spacer 11 is interposed between the enlarged diameter portions 7a and 7a of the deformed core material 7 and between the enlarged diameter portions 16a and 16a of the deformed core material 16 by a plurality of tightening bolts 10a and guide bolts 10b. They are joined to each other. Further, the bolt holes 9a of the guide bolts 10b formed at both ends of the buckling restraint member 9 are formed into elongated holes having a long axis in the material axis direction of the buckling restraint member 9.

In such a configuration, the deformed core material 7 is elasto-plastically deformed in the material axial direction within the range of the elongated holes of the bolt holes 9a with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. (Expand and contract). This makes it possible to absorb large-scale seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 (load-displacement design curve (1)-(2)-(3)-in Fig. 12). (4)-(5)-(6)-(7)).

In addition, in the event of an unexpected large earthquake exceeding level 2, the deformed core material 16 elastically deforms in the direction of the material axis within the range of the elongated hole 16a (load-displacement design curve (3)-(8)-(in FIG. 12). 9)) Further, the connecting portion 7b on the joint portion 5 side of the deformed core material 7 is elastically or plastically deformed (load-displacement design curve (8)-(9)-(10) in FIG. 12).

When the elasto-plastic deformation (elongation) of the deformed core material 7 exceeds the range of the elongated hole of the bolt hole 9a, the axial force acting between the joint portion 5 and the joint portion 6 is transmitted through the buckling restraining material 9. It is transmitted to the deformed core material 16. Further, with respect to the compressive force acting between the joint portion 5 and the joint portion 6, the end portion of the enlarged diameter portion 16a of the deformed core material 16 touches the end portion of the enlarged diameter portion 7a of the deformed core material 7 in a surface manner. As a result, the load is transmitted through the core materials of the deformed core material 7 and the deformed core material 16.

[Embodiment 5]
13 and 14 illustrate a fifth embodiment of the present invention. In the figure, each buckling restraining material 9 is composed of two buckling restraining material units 9A and 9B in the material axial direction, and a rod-shaped stopper 12 for controlling the separation distance between the buckling restraining material units 9A and 9B is installed. However, the configuration is different from that of the bridge collapse prevention material of the fourth embodiment.

Hereinafter, to be described in more detail, each buckling restraining member 9 has a buckling restraint unit 9A on the joint portion 5 side and a buckling restraint on the joint portion 6 side with a substantially intermediate portion in the material axial direction of the deformed core material 16 as a boundary. It is composed of two buckling restraint material units of the material unit 9B.

Each buckling restraint unit 9A has a plurality of tightening bolts 10a and a plurality of tightening bolts 10a on the side surface portions of the enlarged diameter portions 7a and 7a of the deformed core material 7 and the side surface portions of the enlarged diameter portion 16a located on the joint portion 5 side of the deformed core material 16. It is joined by a guide bolt 10b, and a spacer 11 is interposed between the enlarged diameter portions 7a and 7a of the deformed core material 7 and is joined to each other by a plurality of tightening bolts 10a. Further, the bolt holes 9a of the guide bolts 10b formed at the end of the buckling restraining material unit 9A on the joint portion 5 side are formed in elongated holes having a long axis in the material axial direction of the buckling restraining material unit 9A. ..

Each buckling restraint unit 9B is joined to the side surface portion of the enlarged diameter portion 16a located on the joint portion 6 side of the deformed core material 16 by a plurality of tightening bolts 10a, and a spacer 11 is interposed, and the plurality of tightening bolts 10a are interposed. Are joined to each other by.

Further, a plurality of rod-shaped stoppers 12 are arranged along the material axis direction of the buckling restraint unit 9A and 9B on the outside of each buckling restraint unit 9A and the buckling restraint unit 9B in the direction perpendicular to the axis. The rod-shaped stopper 12 is a stopper material for controlling the separation distance between the buckling restraining material units 9A and 9B, and is extended by a predetermined length substantially symmetrically in both directions of the buckling restraining material units 9A and 9B. Then, the end portion 12a of the rod-shaped stopper 12 on the buckling restraint unit 9A side is fixed to the fixing rib 13 projecting from the side of the buckling restraint unit 9A, and is fixed to the buckling restraint unit 9B side. The end portion 12b penetrates loose holes provided in a plurality of fixing ribs 14 projecting from the side portion of the buckling restraint unit 9B, and a retaining stopper 15 is attached to the tip portion.

In such a configuration, the deformed core material 7 is elasto-plastically deformed in the material axial direction within the range of the elongated holes of the bolt holes 9a with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. (Expand and contract). This makes it possible to absorb large-scale seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 (load-displacement design curve (1)-(2)-(3)-in Fig. 14). (4)-(5)-(6)-(7)).

In addition, in the event of an unexpected large earthquake exceeding level 2, the deformed core material 16 elastically deforms in the direction of the material axis within the range of the elongated hole 16a (load-displacement design curve (3)-(8) in FIG. 14). Further, the connecting portion 7b on the joint portion 5 side of the deformed core material 7 is elastically or plastically deformed (load-displacement design curve (8)-(9)-(10) in FIG. 14).

When the elasto-plastic deformation (elongation) of the deformed core material 7 exceeds the range of the elongated hole of the bolt hole 9a, the axial force acting between the joint portion 5 and the joint portion 6 is transmitted through the buckling restraining material 9. It is transmitted to the deformed core material 16. Further, since the rod-shaped stopper 12 is arranged between the buckling restraining material units 9A and 9B, the deformed core material 16 does not break before the connecting portion 7b of the deformed core material 7.

Further, with respect to the compressive force acting between the joint portion 5 and the joint portion 6, the end portion of the enlarged diameter portion 16a of the deformed core material 16 touches the end portion of the enlarged diameter portion 7a of the deformed core material 7 in a surface manner. As a result, the load is transmitted through the core materials of the deformed core material 7 and the deformed core material 16.

[Embodiment 6]
15 and 16 illustrate a sixth embodiment of the present invention. In the figure, the deformed core material 7 is arranged as a single unit between the joint portion 5 and the joint portion 6, and the buckling restraining material 9 is a buckling restraining material unit on the joint portion 5 side with the substantially intermediate portion of the deformed core material 7 as a boundary. It is composed of two buckling restraint units, 9A and the buckling restraint unit 9B on the joint portion 6 side, and is further equipped with a rod-shaped stopper 12 that controls the separation distance between the buckling restraint unit 9A and 9B. However, the configuration is different from that of the fall-prevention material of the fifth embodiment.

Hereinafter, to be described in more detail, the deformed core material 7 is arranged on the material axis between the joint portion 5 and the joint portion 6, and a plurality of buckling restraining members 9 are arranged outside the deformed core material 7 in the direction perpendicular to the axis. There is.

The deformed core material 7 is formed in the shape of an elongated long plate between the joint portion 5 and the joint portion 6 in the material axial direction, and has a side view arrow blade shape at both ends of the deformed core material 7 in the material axial direction. Enlarged diameter portions 7a and 7a having a cross-shaped cross section are formed.

Further, plate-shaped connecting portions 7b and 7b having the same width as the enlarged diameter portion 7a and projecting to the joint portion 5 side and the joint portion 6 side are formed at both ends in the material axis direction, respectively, and the connecting portions 7b and 7b are joints. It is rotatably connected to the portion 5 and the joint portion 6, respectively.

Each buckling restraining material 9 has two buckling restraining materials, a buckling restraining material unit 9A on the joint portion 5 side and a buckling restraining material unit 9B on the joint portion 6 side, with the substantially intermediate portion of the deformed core material 7 as a boundary. It is composed of units, each of which is joined to the side surface of the enlarged diameter portion 7a of the deformed core material 7 by a plurality of tightening bolts 10a and guide bolts 10b, and a spacer 11 is interposed between the enlarged diameter portions 7a and 7a. They are joined to each other by tightening bolts 10a and guide bolts 10b. Further, the bolt hole 9a of the guide bolt 10b formed at the end portion on the joint portion 5 side is formed in a long hole having a long axis in the material axis direction of the buckling restraining material unit 9A.

The rod-shaped stopper 12 is arranged outside the buckling restraint unit 9A and the buckling restraint unit 9B in the direction perpendicular to the axis along the material axis direction of each buckling restraint unit 9A and the buckling restraint unit 9B. In addition, the buckling restraint unit 9A and 9B are extended by a predetermined length substantially symmetrically in both directions.

Further, the end portion 12a of the rod-shaped stopper 12 on the buckling restraint unit 9A side is fixed to the fixing rib 13 projecting from the side of the buckling restraint unit 9A, and the end on the buckling restraint unit 9B side. The portion 12b penetrates a loose hole provided in a plurality of fixing ribs 14 projecting from the side portion of the buckling restraint unit 9B, and a retaining stopper 15 is attached to the tip portion 12a thereof.

In such a configuration, the deformed core material 7 is elasto-plastic in the material axial direction within the range of the elongated hole of the bolt hole 9a with respect to the axial force (tensile force and compressive force) acting between the joint portion 5 and the joint portion 6. Repeat deformation (expansion and contraction). This makes it possible to absorb large-scale seismic energy up to level 2 acting between the end of the bridge girder 1 and the abutment 2 (load-displacement design curve (1)-(2)-(3)-(Fig. 16)-. (4)-(5)-(6)-(7)).

In addition, in the event of an unexpected large earthquake exceeding level 2, the deformed core material 7 elastically deforms in the material axial direction within the range of the elongated holes of the bolt holes 9a (load-displacement design curve (3)-(8) in FIG. 16). )) Further, the connecting portion 7b on the joint portion 5 side of the deformed core material 7 is elastically or plastically deformed (load-displacement design curve (8)-(9) in FIG. 16).

In this way, if there is no design problem even if the cumulative fatigue damage degree of the deformed core material 7 is repeatedly subjected to low strain, in the subsequent unexpected earthquake motion, the remaining capacity of the cumulative fatigue damage degree is used to prevent the collapse of the bridge. It becomes possible to function as a structure.
[Embodiment 7]
FIG. 17 is a seventh embodiment of the present invention, and is a design example in the case where a play area that is displaced in the axial direction without resistance is set in the fourth embodiment. The load-displacement design curve is shown.

The present invention has extremely large deformation capacity and energy absorption capacity during an earthquake, and is not only for the largest earthquake (level 2 seismic motion) within the conceivable range, but also unexpectedly large beyond the range of level 2. It can also respond to earthquakes, and can be used as a bridge collapse prevention material that is attached 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 Bridge collapse prevention material (shock absorber)
4 Bearings 5 Joints 6 Joints 7 Deformation core material (axially deformable member)
7a Enlarged diameter part
7b Connecting part 8 Displacement core material (axial displacement member)
8a Enlarged diameter part
8b Connection 9 Buckling restraint
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 deformed member)
16a Enlarged diameter part
16b connection
17 Telescopic device

Claims (5)

A rod-shaped shock absorbing device having joints at both ends in the material axial direction and expanding and contracting in the material axial direction, and in a first displacement section set as a plastic deformation region, a specific first displacement device constituting the shock absorbing device. While the axially deforming member 1 is elastically deformed or plastically deformed within a range that does not lead to breakage, the displacement is constrained at the upper limit of the first displacement section, and the second displacement section is exceeded and the second plasticity is exceeded. In the second displacement section set as the deformation region, the specific second axially deforming member constituting the shock absorbing device is elastically or plastically deformed, and the specific axial displacement constituting the shock absorbing device is formed. A shock absorbing device comprising a displacement section in which a member is set as a clearance region that is displaced in the axial direction with substantially no resistance in a state where the connection with one of the joint portions is disconnected. In the shock absorbing device according to claim 1, the second axially deforming member exceeds the second displacement section, and the third displacement section set as the third plastic deformation region constitutes the shock absorbing device. A shock absorbing device characterized in that a specific third axially deforming member is elastically deformed or plastically deformed. In the shock absorbing device according to claim 2 , the material of the first axial deforming member, the second axial deforming member and / or the third axial deforming member is a shape memory alloy or a low yield point steel. A shock absorber characterized by using. The shock absorber according to any one of claims 1 to 3 is interposed between the substructure and the superstructure of the bridge having a structure that allows the breakage of the bearing due to a ground motion of level 2 or higher. A bridge equipped with a shock absorber. In the bridge provided with the shock absorbing device according to claim 4, the shock absorbing device is set so as to allow the shock absorbing device to be destroyed by a ground motion of level 2 or higher and less than or equal to the ground motion that the bearing destroys. A bridge equipped with a shock absorber characterized by being present.

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