JP6706071B2 - Function-separated damping structure for bridges - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a function-separated vibration control structure for a bridge that reduces horizontal load from an upper structure such as a bridge girder by using a rod-shaped vibration damping member and reliably transmits the load to a lower structure such as an abutment or a pier.

Conventionally, steel bearings have often been used for bridge support structures for abutments and piers, but after the Great Hanshin Earthquake, the seismic structure for bridge support structures was reviewed on a nationwide scale. So-called seismic isolation type bridges using seismic isolation bearings mainly made of elastic material such as rubber bearings with lead plugs have been adopted.

In particular, rubber bearings have been adopted in earnest since the 1996 revision of the road bridge specification. However, vertical bearings, horizontal load bearings, securing horizontal movement amount, and rotation amount due to girder deflection are included in one bearing. In order to have all the functions such as securing the bearing, the bearing size becomes large, and it is often uneconomical including the girder structure.

Against this background, a function-separated type bearing has been developed in order to reduce the size and cost of rubber bearings, and the number of adoptions has increased since it was described in the 2004 revision of the Road Bridge Bearing Manual. .. The function-separated bearing is a general term for bearing systems that separate the function of supporting vertical force and the function of supporting horizontal force during an earthquake.

Regarding the function-separated type support, for example, in Patent Document 1, a sliding support that supports a vertical load of the upper structure so that the upper structure is movable in the horizontal direction and a horizontal support without supporting the vertical load of the upper structure are provided. It is equipped with a horizontal load support mechanism that supports horizontal load of the upper structure by shearing in all directions, and the horizontal load support mechanism is fixed to the upper surface of the lower structure and a gap is formed between the upper load and the upper structure. An elastic body having a rectangular flange plate to be formed, and fixed to the lower surface of the upper structure, engageable with the circumferential surface of the flange plate along the bridge axis direction and the direction perpendicular to the bridge axis, and there is a gap in the lower surface of the flange plate. There is disclosed a function-separated bridge support device including an engagement member which is engageable via the support member and also supports an upper lift force.

In addition, Non-Patent Document 1 discloses the features, merits, types, and points to note when adopting a function-separated type bearing.

As shown in Non-Patent Document 1, when a steel support is used as the (a) vertical support for the function-separated type support, the vertical rigidity is high and there is no sinking due to live load, so it is possible to suppress the occurrence of vibration. (b) Since the horizontal bearing does not support vertical load, the shape is not determined by the vertical load unlike the rubber bearing described above, and the degree of freedom in design is increased by miniaturization, and horizontal rigidity can be set freely. Although it has the advantage that the natural period of the bridge can be adjusted arbitrarily, the space under the girder is narrowed because the height of the vertical bearing is low, and there are multiple vertical bearings and horizontal bearings. The problem that the work space is narrowed due to the installation of the bearings has come to the surface.

In particular, for the vertical type concrete reaction wall type, (1) there is no stopper on the horizontal bearing, so movement cannot be restricted until the concrete reaction wall is completed.(2) Horizontal bearing on the concrete reaction wall Anchor bolt type is often used as a fixing method for the above, but cracks may occur in the concrete reaction wall due to the movement of the horizontal bearing due to the temperature expansion and contraction of the girder. (3) The concrete reaction wall should be constructed. It has become clear that the problem is that it takes time and cost.

On the other hand, many bridges were damaged by the Great East Japan Earthquake that occurred in March 2011, and damage reports such as damage to bearing side blocks and damage to steel brackets for displacement limiting structures have been reported. In particular, it has been regarded as a problem that even the bridges that have undergone earthquake resistance measures were damaged, and it is urged to re-examine it in preparation for a future big earthquake such as the Nankai Trough earthquake.

Regarding the problem of the conventional function-separated type bearing as described above, in addition to this, in the bridge, the reaction force (horizontal load) equivalent to the horizontal force of the upper structure is transmitted to the lower structure. In order to deal with a level 2 or greater large earthquake such as the above, it is necessary to make the reaction walls and the substructure larger or to reinforce them so that they have sufficient proof strength. However, these measures cause a problem that much labor and cost are required for the construction.

On the other hand, the applicant of the present application, as shown in Patent Document 2, in addition to the support for supporting the vertical load from the main girder of the upper structure on the lower structure of the bridge, the fixed column located between the main girders. The vertical load-supporting mechanism and the horizontal load-supporting mechanism are separated by a bar-shaped damping member that suppresses vibration in the axial direction of the member between the fixed column and the main girders on both sides for horizontal load. In this type of damping structure, the main girder is provided with a joint for supporting and fixing the rod-shaped damping member, and a horizontal load support member consisting of a pair of rod-shaped damping members is arranged symmetrically about the fixed column. The rod-shaped damping member has one end attached to the fixed column and the other end fixed to the joint provided on the main girder, and the horizontal load supporting member reduces the horizontal load from the upper structure to lower the lower structure. We are developing a function-separated type vibration control structure for bridges.

In the structure disclosed in Patent Document 2, since it is possible to reduce the horizontal load, it is not necessary to upsize the lower structure because the lower reaction force is also reduced. The advantage is that substructure reinforcement is not required, and reinforcement work against large-scale earthquake motions can be performed efficiently.

Japanese Patent No. 3634288 JP, 2005-031046, A

"Selection of function-separated type bearing and proposal of steel deck slab end structure", Japan Bridge Construction Association Design Subcommittee Structural Technology Subcommittee, 2011 Technology Presentation, P1-1 to P1-14

In a bridge, relative movement may occur in the bridge axial direction between the upper structure and the lower structure due to seismic motion, traffic vibration, thermal expansion, or the like.

On the other hand, in Patent Document 2 described above, the end portion of the rod-shaped damping member is arranged so that the joint between the fixed column and the rod-shaped damping member can follow the relative movement of the lower structure and the upper structure in the bridge axis direction. A mechanism is shown in which the tightly connected connecting bolt slides in the bridge axial direction along a long slot for sliding provided in the connecting plate for attaching to the fixed column side.

However, by providing the sliding mechanism, the integration of the rod-shaped damping members is impaired, and when the connecting plates slide in the sliding direction, the connecting plates do not contact each other when only the connecting bolts are tightened. The initial width cannot be maintained, and the rod-shaped damping members on both sides of the fixed column lose their linear positional relationship (see FIG. 9 ), which may partially impair the original function of the horizontal load supporting mechanism. .

In addition, it is designed so that the side blocks installed on the main girder support can deal with the upper lift and horizontal movement restrictions, but a bar-shaped damping member against horizontal load during a Level 2 earthquake. In order to function, it is necessary to be able to move in the horizontal load direction. The design conditions for horizontal movement are that the displacement constraint function is always and in the horizontal direction during a Level 1 earthquake. In the fixed state and during a level 2 earthquake, it is necessary that the rod-shaped damping member be capable of horizontal movement so that it can exert its damping function.

That is, with respect to upper positive force and horizontal movement restriction, the side block etc. always exert its function at the time of a level 1 earthquake, but need to be designed not to exert its function at the level 2 earthquake. Since the function to suppress the above is also lost, it becomes necessary to supplement the function separately, which leads to an increase in the size of the bearing and impairs the significance of the function-separated type bearing.

On the other hand, it may be possible to separately install a mechanism for suppressing the upper lift force against seismic motions of level 2 or higher between the lower structure and the upper structure. In that case, the upper lift force suppressing mechanism becomes large or the functions are separated. There are problems such as compatibility with mold bearings and tracking of relative movement in the horizontal direction.

The present invention provides a function-separated type vibration damping structure in which a bar-shaped vibration damping member is interposed between a fixed column and main girders on both sides of the fixed column for horizontal loads, and the fixed column and the bar-shaped damping system are provided even for large earthquakes of level 2 or higher. It is an object of the present invention to provide a function-separated vibration control structure for bridges in which the vibration member can follow the movement of the superstructure in the bridge axis direction and further has an efficient upper lift suppressing mechanism using fixed columns. ..

According to the present invention, in addition to a support for supporting a vertical load from a main girder of an upper structure, a fixed column located between main girders is provided in a lower structure of a bridge, and the fixed column and main girders on both sides of the fixed column with respect to a horizontal load. By interposing a rod-shaped damping member that suppresses vibration in the member axial direction between them, in the function-separated type damping structure of the bridge in which the vertical load supporting mechanism and the horizontal load supporting mechanism are separated, the rod-shaped vibration damper is consolidated through a respective connecting plate, connecting plate on both sides and the fixed pillar penetrates the long hole extending in the bridge axis direction formed in the fixed post or the connection plate Are connected by rod-shaped tension members that tightly connect the connecting plates on both sides, and the tension members slide along the long holes in response to relative movement in the bridge axial direction between the lower structure and the upper structure of the bridge. The connecting plates are structured so as to allow relative movement in the bridge axis direction of the fixed columns connected to each other via the connecting plates and the rod-shaped damping members on both sides thereof , and the connecting plates are located on both sides of the fixed columns. Across the upper end of the fixed column, by integrating through the plate-shaped member that connects and fixes the connecting plates on both sides , relative to the relative movement in the bridge axial direction of the lower structure and the upper structure of the bridge, It is characterized in that the linear positional relationship between the rod-shaped damping members on both sides of the fixed column is maintained.

In the function-separated vibration control structure that has a horizontal load support mechanism separated from the vertical load support mechanism, it is possible to reduce the horizontal load. The advantage is that there is no need to increase the size or the need to reinforce the substructure by rolling up steel sheets, etc., and the reinforcement work against large-scale earthquake motions can be performed efficiently.

In the function-separated vibration damping structure of the present invention, a horizontal load support member including a pair of rod-shaped vibration damping members is used to reduce the horizontal load from the upper structure and transmit the horizontal load to the lower structure. Examples of the rod-shaped damping member include a buckling restraint brace, a friction damper, an oil damper, and the like. By using these rod-shaped damping members, the bridge can be easily damped by reducing the horizontal load from the upper structure and transmitting it to the lower structure without increasing the size of the lower structure or reinforcing it. It can also add earthquake resistance.

Of these, the buckling restraint brace was developed as a sacrificial member of a structure, and when a large-scale earthquake motion acts on the structure, it plastically deforms a region with a brace core material to absorb seismic energy and A rod-shaped vibration damping device capable of controlling vibration damping, for example, JP 2012-013157 A, JP 2003-193699 A, JP 2001-214541 A, and JP 2000-027293 A. And the like. By using this as the rod-shaped damping member of the present invention, even when a large-scale earthquake of level 2 or more occurs, the effect of absorbing the seismic energy can be obtained by concentrating the member damage on the buckling restraint brace. ..

The member length of the rod-shaped damping member is determined by the space where the abutments or piers can be installed. For example, in the case of a two-main girder bridge, the length required for the joints of each main girder and the width of the fixed column is excluded It will be half. Further, in the function-separated type vibration damping structure of the present invention, the bar-shaped vibration damping member (horizontal load) (horizontal load) A fixed column for supporting the support member) is provided.

The fixed column is mainly made of steel, and is not particularly limited as long as the pair of rod-shaped vibration damping members (horizontal load supporting members) have a structure that can be installed horizontally and axisymmetrically around the fixed column and is strong. .. For example, an H-shaped one mainly made of H-shaped steel, a square tube-shaped one using a square steel pipe, and the like. The cross-sectional dimension of the fixed column is determined by the bending strength from the superstructure. For example, if the rod-shaped damping member is installed at a position where the yield axial force is 500 kN and the installation height is approximately 500 mm, the cross-sectional height is approximately 500 mm. is there.

In the function-separated type vibration damping structure of the present invention, the main girder of the bridge is provided with a joint portion for supporting and fixing the rod-shaped vibration damping member, and is composed of a pair of the rod-shaped vibration damping members in line symmetry about the fixed column. A horizontal load supporting member is horizontally arranged in the direction perpendicular to the bridge axis, one end of the rod-shaped damping member is attached to the fixed column via a connecting plate, and the other end is fixed to the joint portion.

By arranging the horizontal load support members horizontally in the direction orthogonal to the bridge axis, the horizontal load from the upper structure can be directly attenuated and transmitted to the lower structure in the seismic design in the same direction. Further, by arranging the pair of rod-shaped damping members in line symmetry around the fixed column, the horizontal load is transmitted from the upper structure by the tension of one rod-shaped damping member and the compression of the other rod-shaped damping member. Are carried out simultaneously, the transfer of horizontal load to the undercarriage is reduced.

In this way, the pair of rod-shaped damping members are provided line-symmetrically in the transmission portion from the upper structure to the lower structure, and the tensile load and the compressive load are simultaneously received, so that the horizontal load supporting member (horizontal load supporting mechanism) The proof strength is increased, and the bridge can be efficiently provided with earthquake resistance without increasing the size of the substructure or significantly reinforcing it.

The joint is a portion provided on the main girder of the bridge to support and fix the rod-shaped damping member.For example, when the joint is a friction joint, a high strength force is applied so that the splice plate can be attached. This is a portion made of a steel member having a structure such as a gusset plate provided with bolt holes.

In such a structure, in the present invention, the fixed column and the rod-shaped damping members on both sides thereof are connected to each other through connecting plates so as to allow relative movement in the bridge axis direction, and are located on both sides of the fixed column. By integrating the connecting plates with the fixing member, the linear positional relationship between the rod-shaped damping members on both sides of the fixed column is relative to the relative movement of the bridge lower structure and the upper structure in the bridge axial direction. I am trying to maintain it.

As a structure that allows relative movement in the bridge axis direction while connecting the fixed column and the rod-shaped damping members on both sides thereof via the connecting plate, for example, as described in Patent Document 2 mentioned above, the fixed column or A long hole extending in the bridge axis direction was formed in the connecting plate, and it was provided at the end of the fixed column and the vibration damping member with a rod-shaped tension member that penetrates this long hole and tightly connects the connecting plates on both sides. There is a structure in which connecting members are connected to each other so that the tension member slides along the long hole with respect to the relative movement of the lower structure and the upper structure in the bridge axis direction.

However, in the structure described in Patent Document 2, when the connecting plates slide in the sliding direction, the connecting plates cannot hold the initial width, so that they slide sufficiently smoothly at the fixed column position. However, as shown in FIG. 9, which will be described in detail later, the rod-shaped vibration damping members on both sides of the fixed column cannot hold a linear positional relationship, and thus the essential function as a horizontal load supporting mechanism. May be partially damaged.

On the other hand, in the present invention, by connecting the connecting plates located on both sides of the fixed column via the fixing member, it becomes possible for the connecting plates to maintain their original widths, and The linear positional relationship between the rod-shaped damping members on both sides of the fixed column should be maintained against relative movement of the superstructure in the bridge axis direction so that the original function as a horizontal load support mechanism is not impaired. It is the one.

As one of the forms of the fixing member for integrating the connecting plates located on both sides of the fixed column, it is possible to use a plate-shaped member that straddles the upper end of the fixed column and connects and fixes the connecting plates on both sides. it can. For example, by providing overlapping portions on the connecting plate and the plate-shaped fixing member and bolting them together, or by welding the connecting plate and the plate-shaped fixing member to make a rigid connection, the rod-shaped control members on both sides of the fixed column can be formed. Maintain a linear positional relationship between the vibration members.

When the rigidity cannot be ensured only by the upper side of the fixed column, a plurality of fixing members may be arranged so as to surround the fixed column by further disposing the fixing member also on the lower side of the connecting plate.

In order to smoothly follow the movement of the superstructure in the bridge axis direction, it is desirable that a small gap rather than close contact be made between the fixed column and the connecting plates on both sides. As such, use of a width-holding pipe that straddles a fixed column and holds the space between the connecting plates on both sides and a rod-shaped tension member that penetrates the width-holding pipe and tightly connects the connecting plates on both sides. You can

By using steel pipes, etc. for the width-holding pipes, when the connecting plates on both sides are tightened with the tension material that has passed through the width-holding pipes, an interval corresponding to the length of the width-holding pipe is maintained between the connecting plates on both sides. Therefore, by setting the length of the width holding pipe to be equal to or greater than the width of the fixed column in the direction perpendicular to the bridge axis, the tightening between the fixed column and the connecting plate is relaxed, and the movement of the superstructure in the bridge axis direction is reduced. It can follow smoothly.

The fixing member of each of the above-described forms can be used alone or in combination of two or more depending on the conditions.

Furthermore, in the function-separated vibration damping structure of the bridge of the present invention, when a horizontal girder connecting the main girders is provided between the main girders, relative movement in the vertical direction between the fixed column and the lateral girder is prevented. An upper lift resistance mechanism for restraining may be provided.

This upper lift resistance mechanism is also preferably a structure that can follow the movement of the upper structure in the bridge axis direction. For example, as the above-mentioned fixing member, a plate that straddles the upper ends of the fixed columns and connects and fixes the connecting plates on both sides. When a plate-shaped member is used, this plate-shaped member is joined to the cross beam through a steel material having a predetermined rigidity, and a stiffening member is attached to the cross beam, etc., if necessary, so that The lift resisting mechanism can be easily formed, and can function as an effective upper lift resisting mechanism, for example, in the case where the side blocks of the support portion are not effective against level 2 or higher earthquake motion.

The function-separated type vibration control structure of the bridge of the present invention can be simply installed, and can effectively reduce the horizontal load from the upper structure and transmit it to the lower structure, thus increasing the size and reinforcement of the lower structure. In addition to the effect that it is possible to reduce the damage and effectively add earthquake resistance to the bridge even for a large earthquake of level 2 or higher, the connecting plates on both sides of the fixed column are integrated by the fixing member. , It is possible to follow the movement of the superstructure in the bridge axis direction while maintaining the linear positional relationship of the rod-shaped damping members on both sides of the fixed column, and to fully exert the function of the rod-shaped damping member. it can.

In addition, by installing an upper lift resistance mechanism that restrains the relative movement in the vertical direction between the fixed column and the transverse girder, the fixed column for constructing the function-separated type vibration control structure is installed above the level 2 seismic motion. It can also function as a lift resistance mechanism.

It is a perspective view showing roughly an example of the functional separation type damping structure of the present invention. It is a perspective view which shows an example of the rod-shaped damping member by a buckling restraint brace. It is a perspective view which shows the detail of the fixed pillar part fixed on the lower structures, such as a bridge pier. It is a perspective view which shows the detail at the time of fixing a fixed pillar to the upper side surface of a lower structure. It is a perspective view which shows the detail at the time of providing an upper lift force resistance mechanism in a fixed pillar part. It is a perspective view which shows the other example at the time of providing an upper lift force resistance mechanism in a fixed pillar part. It is explanatory drawing which showed notionally the behavior when the level 1 seismic motion always acts on the function separation type damping structure of this invention. It is explanatory drawing which showed notionally the behavior when the level 2 seismic motion acts on the function separation type damping structure of this invention. It is explanatory drawing which showed notionally the behavior when a rapid seismic motion acts on the conventional function separation type damping structure. It is explanatory drawing which showed notionally the case of the function isolation type damping structure of this invention contrasted with FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below.

FIG. 1 schematically shows an example of the function-separated vibration damping structure of the present invention. The bridge 1 in this example comprises a main girder 6, 6 in the bridge axis direction, a transverse girder 3 in the direction perpendicular to the bridge axis, a floor slab 2 installed on these, on a substructure 5 such as an abutment/pier. A superstructure 4 consisting of

This bridge 1 has a function-separated type vibration control structure, and a horizontal load support including fixed columns 7, a pair of rod-shaped vibration control members 8 and 8 (horizontal load support members) composed of buckling restrained braces, and a joint portion 9 and the like. The mechanism is provided in the direction perpendicular to the bridge axis. The vertical load support mechanism depends on the bearing 12. Examples of the bridge 1 include a steel bridge, an RC bridge, a PC bridge and the like.

A fixed column 7 for supporting the rod-shaped vibration damping members 8, 8 is provided on the upper part of the intermediate lower structure 5 in the direction perpendicular to the bridge axis between the main girders 6, 6 which are parallel to each other and parallel to each other in the bridge axis direction. Each main girder 6 is provided with a joint 9 for supporting and fixing the rod-shaped damping member 8, and a horizontal load supporting member composed of a pair of rod-shaped damping members 8 is arranged symmetrically about the fixed column 7 as a bridge. The rod-shaped vibration damping members 8 are arranged horizontally in the direction orthogonal to the axis, one end of each rod-shaped damping member 8 is attached to the fixed column 7 via the connecting plate 14, and the other end is fixed to the joint 9.

In this example, the fixed column 7 has an H shape mainly made of H-shaped steel, and is mounted on the upper surface of the lower structure 5 (abutment/pier). The joint 9 is intended to be integrated with the upper structure 4, and is made of a steel plate, high-strength bolt, or the like, and is provided on the side surface of each main girder 6 in this example.

Then, the horizontal load supporting member reduces the horizontal load from the upper structure 4 and transmits it to the lower structure 5. Specifically, for example, when the bridge 1 shakes due to a large-scale earthquake or the like and the axial force of the rod-shaped damping member 8 reaches the set load, the damper function is exerted so that the horizontal load from the superstructure 4 remains unchanged. It is possible to reduce these loads without transmitting them to the lower structure 5.

In such a structure, as shown in FIG. 5 which will be described in detail later, by connecting the connecting plates 14 located on both sides of the fixed column 7 through the fixed plate 41 serving as a fixing member, the fixed column 7 is fixed. The tightening between the connecting plate 14 and the connecting plate 14 is relaxed, and the rod-shaped damping members 8, 8 on both sides of the fixed column 7 are linear with respect to the relative movement of the lower structure 5 and the upper structure of the bridge in the bridge axial direction. The positional relationship is maintained, and an upper lift resistance mechanism 61 for restraining relative movement in the vertical direction is provided between the fixed column 7 and the horizontal girder 3 by using the fixed plate 41. In a situation where the side block 13 resisting the lift force at the bearing 12 position against the earthquake motion does not work, the lift force resistance function is exerted.

FIG. 2 shows an example of the rod-shaped vibration damping member 8 using the buckling restraint brace. The buckling restraint brace shown in the figure consists of a load bearing part made of low yield point steel with a cross-shaped fin cross section, and a load bearing part made of general steel in which the width and thickness of each fin are made larger than the load bearing part. Has a core member 21 including an end member welded and fixed to one end of the load receiving portion and an end member welded and fixed to the other end of the load receiving portion.

At each of the four corners of the core member 21, buckling prevention members 22 made of chevron steel having a width equal to the width of each fin of the end member of the core member 21 are arranged. , Has a length that spans the end member and a part of the end member.

A spacer having a thickness equal to the thickness of the fin of the end member is arranged outside each fin of the load receiving portion of the core member 21, and the buckling prevention member 22 separates a part of the end member from the spacer. The assembly bolt 23 (high-strength bolt) and the assembly nut are sandwiched and tightened with an assembly nut to be integrally assembled.

A long hole 25 is formed at a position where one end of the buckling prevention member 22 is attached to a part of the end member by the assembly bolt 23. Therefore, when the assembly bolts 23 are tightened, a gap is formed between the load receiving portion of the core member 21 and the buckling prevention member 22, and thus a tensile or compression load is applied between the end members of the core member 21. When the force acts, the load receiving portion undergoes tensile deformation or compression deformation. At this time, the buckling prevention member 22 allows the length change of the load receiving portion by the long hole 25, and the buckling prevention member 22 acts so as to resist the load which the load receiving portion tries to buckle. ..

A connecting plate 14 having a top end hanging plate 15 at the upper end is provided at one end of the core member 21. The buckling restraint brace (bar-shaped damping member 8) is attached to the fixed column via the connecting plate 14. In the installed state, the connecting plate 14 is in surface contact with the fixed column main body (flange portion) at the time of compression to transmit the load, and at the time of pulling, the connecting plate 14 penetrates the fixed column to connect the connecting plates 14 on both sides via the connecting bolt. And the top end hanging plate 15 at the upper end of the connecting plate 14 supports the self-weight of the rod-shaped damping member 8 on the fixed column, and the rod-shaped damping member 8 has a function of transmitting the axial force from the other connecting plate 14. It plays a role in smooth movement in the direction perpendicular to the axis.

In the present invention, as one form, a fixed plate that integrates the connecting plates 14 on both sides of the fixed column can be attached to the upper surface of the top plate 15, and in the illustrated example, the fixed plate is attached to the top plate 15. A mounting hole 16 is provided so that the fixed plate 41 (see FIGS. 1 and 3 to 6) can be bolted.

Further, the connecting plate 14 is provided with a long slide hole 17 as shown in the drawing. The long hole 17 for sliding plays a role of performing a movable function in the bridge axis direction to follow the movement of the superstructure in the bridge axis direction.

Further, in the illustrated example, a tension bolt 52 is formed in the lower portion of the connecting plate 14 in the front-back direction in the bridge axis direction, and a tension bolt 52 is passed through a width holding pipe 51 described later in the overhang portion (see FIGS. 3, 4, and 6). Is provided with a bolt hole 18 for fixing.

FIG. 3 shows details of a fixed column 7 portion fixed on a lower structure 5 such as a bridge pier.

The fixed column 7 is composed of a base plate 29 and a fixed column main body made of H-shaped steel that is placed and fixed on the base plate 29, and an anchor bolt is provided on the upper surface of the lower structure 5 such as an abutment or a pier via a height adjusting mortar 28. It is installed by being fixed to the lower structure 5 at 30. In addition, the flange of the H-section steel is provided with a hole for inserting the connecting bolt 27 in addition to the elongated slide hole 17 provided in the connecting plate 14.

The mounting structure of the pair of rod-shaped vibration damping members 8, 8 (in this example, the buckling restraint brace) to the fixed column 7 is as shown in the figure. That is, in the rod-shaped damping member 8 having the long hole 17 for sliding, the connecting plate 14 at the end of the rod-shaped damping member 8 is superposed on the flange of the H-shaped steel that is the main body of the fixed column 7 and is fixed by the connecting bolt 27. It is attached to 7.

As described above, the slide long hole 17 has a function of performing a function of moving in the bridge axis direction to follow the movement of the superstructure in the bridge axis direction. Specifically, for example, a rectangular nut 31 with a protrusion is installed in the sliding long hole 17 provided in the connecting plate 14, so that the long hole 17 serves as a guide rail and is movable in the following direction.

According to the present invention, in such a configuration, the connecting plates 14 located on both sides of the fixed column 7 are integrated with each other through the fixing member, so that the tightening between the fixed column 7 and the connecting plate 14 is relaxed. With respect to the relative movement of the lower structure 5 and the upper structure of the bridge in the bridge axial direction, the linear positional relationship between the rod-shaped damping members 8 on both sides of the fixed column 7 is maintained to support the horizontal load. The original function of the mechanism is kept intact.

In the example of FIG. 3, specifically, as a fixing member, a fixed plate 41 that straddles the upper end of the fixed column 7 and connects and fixes the connecting plates 14 on both sides to each other is used. The width holding pipe 51 made of steel is interposed at the position of the overhanging portion, and the connecting plates 14 on both sides are tightly connected with the tension bolt 52 passing through the width holding pipe 51 to surround the fixed column 7. The connecting plates 14, 14 on both sides are integrated with each other by the tension bolts 52 passing through the upper fixed plate 41 and the lower width holding pipe 51, which are arranged in FIG.

In such a configuration, since the fixed plate 41 as the fixing member and the width holding pipe 51 hold a space corresponding to the length of the width holding pipe 51 between the connecting plates 14 on both sides, the width holding pipe 51. By making the length of the fixed column more than the width of the fixed column in the direction perpendicular to the bridge axis, the tightening between the fixed column 7 and the connecting plate 14 can be relaxed and smoothly follow the movement of the superstructure in the bridge axis direction. You can

FIG. 4 shows details of the case where the fixed column is fixed to the upper side surface of the lower structure. In this example, the fixed column 7 is composed of a fixed column body made of H-shaped steel and two fixing plates 32, 32 having holes for passing the anchor bolts 30. Then, the flange of the H-section steel has a hole for inserting the connecting bolt 27 together with the long hole 17 for sliding provided in the connecting plate 14, and the H-section web has a hole for inserting the anchor bolt 30. Each is provided.

As shown in the figure, the fixed column 7 is installed by sandwiching H-shaped steel between two fixing plates 32, 32 and fixing it to the upper side surface of the lower structure 5 with anchor bolts 30.

The mounting structure of the pair of rod-shaped vibration damping members 8, 8 (in this example, the buckling restraint brace) to the fixed column 7 is the same as that in the case of FIG.

FIG. 5 shows details of the fixed column 7 portion in the embodiment of FIG. 1 described above. As described with reference to FIG. 1, the connecting plates 14 located on both sides of the fixed column 7 are integrated with each other via the fixed plate 41, and the fixed plate 41 is used between the fixed column 7 and the cross beam 3. An upper lift force resistance mechanism 61 for restraining relative movement in the vertical direction is provided.

In this example, the width holding pipe 51 and the tension bolt 52 used in the embodiments of FIGS. 3 and 4 are not provided, but a more stable structure is provided by providing the width holding pipe 51 and the tension bolt 52 as in FIG. Becomes

By integrally connecting the connecting plates 14 and 14 via the fixed plate 41, the tightening between the fixed column 7 and the connecting plate 14 is relaxed, and the bridge lower structure 5 and the upper structure are relatively opposed to each other in the bridge axial direction. With respect to the movement, it is possible to smoothly follow the relative movement in the bridge axis direction while maintaining the linear positional relationship between the rod-shaped damping members 8 on both sides of the fixed column 7.

In the illustrated example, as the upper lift resistance mechanism 61, steel plates are combined, and the lower joining plate of the connecting block 62 having upper and lower joining plates is bolted to the fixed plate 41 to join the upper portion of the connecting block 62. The plate is bolted to the lower flange of the cross beam 3, and rib-shaped stiffening members 63 and 64 are attached to the web portion of the cross beam 3 to which the stress of the connecting block 62 is transmitted.

As described above, for example, in a situation where the side block 13 resisting the lift force at the bearing 12 position does not work against seismic motion of level 2 or higher, the fixed column 7 and the cross beam 3 are connected via the lift force resistance mechanism 61. Since they are indirectly joined, the upper lift resistance function can be exerted.

Further, since the fixed plate 41 can move relative to the fixed column 7 in the bridge axis direction, substantially only the vertical force acts on the upper lift resistance mechanism 61.

FIG. 7 shows the behavior when the function-separated vibration control structure of the present invention is constantly or when level 1 seismic motion is applied, and FIG. 8 is the behavior when the level 2 seismic motion is applied to the function-separated vibration control structure of the present invention. It is shown in the figure.

As shown in Fig. 7, the bearing that receives the main girder bears vertical vibrations at all times or against level 1 seismic motion, and the bearing is in a substantially fixed state even for lift. It can resist by the stopper function of the position side block.

With respect to the relative movement in the bridge axis direction due to constant heat expansion, etc., the structure is such that the fixed column position can follow the displacement as described above.

In Fig. 8(a), the upper structure is largely displaced horizontally to the right in the figure due to a level 2 or higher earthquake motion, a tensile axial force acts on the right bar-shaped damping member being fixed, and the left bar-shaped damping member is compressed. It shows how the axial force acts.

In this state, the support portion of the support portion is released from the stopper function of the side block and can be slid. The lifting force at this time is borne by the fixed column connected to the cross beam (in the case of the embodiments of FIGS. 1, 5, and 6).

Similarly, Fig. 8(b) shows that the upper structure is largely displaced horizontally to the left in the figure due to seismic motion of level 2 or higher, and a tensile axial force acts on the right bar-shaped damping member that is being fixed, and the left bar-shaped damping member is 8A and 8B are repeated, the horizontal vibration is attenuated by absorption of vibration energy by the rod-shaped damping member. ..

FIG. 9 conceptually shows the behavior when a sudden seismic motion acts on the conventional function-separated type vibration control structure, and FIG. 10 shows the function-separated type vibration control structure of the present invention in comparison with FIG. This is a conceptual illustration of the case.

As described above, in the structure of FIG. 9A in which the connecting plates 14 on both sides of the fixed column 7 are tightly connected to each other with the connecting bolts 27, and the connecting plate 14 is directly pressed against the fixed column 7. It is difficult to sufficiently follow the movement of the superstructure in the bridge axis direction even if the sliding structure is slid along the long slot for sliding, and as shown in Fig. 9(b), the rod-shaped rods on both sides at the fixed column 7 position. There is a risk that the vibration damping members 8, 8 will not be in a straight line and will be bent at an angle, and the function of the rod-shaped vibration damping member 8 cannot be fully exerted.

On the other hand, in the structure of the present invention, the connecting plates 14 on both sides of the fixed column 7 are rigidly integrated by the fixing members such as the fixed plate 41 and the width holding pipe 51, so that the rod-shaped control on both sides of the fixed column 7 is controlled. Since the relative movement of the upper structure can be made to follow in a state where the linear positional relationship between the vibration damping members 8 is maintained, the function of the rod-shaped vibration damping member 8 can be sufficiently exerted.

DESCRIPTION OF SYMBOLS 1... Bridge, 2... Floor slab, 3... Horizontal girder, 4... Upper structure, 5... Lower structure, 6... Main girder, 7... Fixed column, 8... Rod damping member, 9... Main girder side joint part,
12... Support, 13... Side block (stopper), 14... Connecting plate, 15... Top end hanging plate, 16... Fixed plate mounting hole, 17... Sliding long hole, 18... Bolt hole,
21... Core material, 22... Buckling restraint material, 23... Assembly bolt, 25... Long hole,
27... Connection bolts, 28... Height adjusting mortar, 29... Base plate, 30... Anchor bolts, 31... Grooved square nuts, 32... Fixed plate 41... Fixed plate,
51... Width holding pipe, 52... Tension bolt,
61... Upper lift resistance mechanism, 62... Connection block, 63... Stiffening member, 64... Stiffening member

Claims (4)

In addition to the support that supports the vertical load from the main girder of the superstructure, the bridge substructure is provided with fixed columns located between the main girders. In a function-separated vibration control structure of a bridge in which a vertical load support mechanism and a horizontal load support mechanism are separated by interposing a rod-shaped vibration control member that suppresses vibrations in the direction, the fixed column and the bar-shaped vibration control on both sides of the fixed column member is consolidated through a respective connecting plate, connecting plate on both sides of the fixed column, the sides of the through long hole extending in the bridge axis direction formed in the fixed post or the connection plate The connecting plates are connected by a rod-like tension member that tightly connects the connecting plates, and the tension member slides along the long hole in response to relative movement in the bridge axial direction of the lower structure and the upper structure of the bridge, so that the connecting plate is Has a structure that allows relative movement in the bridge axis direction between the fixed column and the rod-shaped damping members on both sides of the fixed column , and the connecting plates located on both sides of the fixed column are fixed to each other. Straddling the upper end of the bridge, and integrating them through the plate-shaped members that connect and fix the connecting plates on both sides, so that both sides of the fixed column are supported against relative movement in the bridge axial direction between the lower structure and the upper structure of the bridge. A function-separated vibration control structure for bridges, characterized in that the linear positional relationship between the rod-shaped vibration control members of FIG. Function separation type damping smell of bridges according to claim 1 wherein Te, straddling the upper portion of said fixed column, adding both sides of the connecting plate to each other in the plate-like member to be connected and fixed, further bridge axis direction of the fixed pillar and tendons of the across front and rear sides respectively before Symbol fixed pillar through the width holding pipe for holding the interval of the connecting plate to each other on both sides of the width maintaining pipe to the connecting plate to each other Tightened on both sides rod-like A function-separated vibration control structure for a bridge, characterized in that the connection plates located on both sides of the fixed column are enhanced in integrity by providing a fixing member made of . The function-separated vibration damping structure for a bridge according to claim 2, wherein the length of the width-maintaining pipe is equal to or greater than the width of the fixed column in a direction perpendicular to the bridge axis. The function-separated vibration control structure for a bridge according to claim 1, 2 or 3 , wherein a transverse girder connecting the main girders is provided between the main girders , straddling the upper end portion of the fixed pillar , and Between the plate-shaped member and the cross girder for connecting and fixing the connecting plates to each other, the plate- shaped member and the cross girder are connected to each other to restrain the vertical movement of the lower structure and the upper structure of the bridge. A function-separated vibration control structure for bridges, which is equipped with a lift resistance mechanism.