JP2017122365A - Function separation type vibration damping structure for bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a function separation type motion damping structure for a bridge that can follow up a movement of an upper structure in a bridge axial direction even in a case of large earthquake motion of level 2 or higher, and also comprises an efficient lift force suppressing mechanism.SOLUTION: A vertical load bearing mechanism and a horizontal load bearing mechanism are separated by providing a lower structure 5 of a bridge 1 with a fixed column 7 located between main girders 6 of the upper structure 4 in addition to a support 12 supporting a vertical load from the girders 6, and also interposing a rod-like motion damping member 8 which suppresses motion in a member axial direction between the fixed column 7 and girders 6 on both sides thereof against a horizontal load. The fixed column 7 and the rod-like motion damping members 8 on both the sides thereof are so coupled as to allow relative motion in a bridge axial direction through coupling plates 14 respectively. Further, the coupling plates 14 on both the sides of the fixed column 7 are united together through a fixing board 41 so as to maintain linear position relation between the rod-like motion damping members 8 on both the sides of the fixed column 7 against relative motion of the upper structure 4 in the bridge axial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a function-separated type damping structure for a bridge that uses a rod-shaped damping member to reduce a horizontal load from an upper structure such as a bridge girder and reliably transmits it to a lower structure such as an abutment or a pier.

  Conventionally, steel bearings have been used for bridge support structures for abutments and piers. However, after the Great Hanshin Earthquake, the earthquake resistance structure for bridge support structures has been reviewed nationwide. Bridges of so-called seismic isolation structures using seismic isolation bearings mainly composed of elastic bodies such as rubber bearings with lead plugs have been adopted.

  In particular, rubber bearings have been adopted in earnest since the revision of the specifications for road bridges in 1996, but vertical load support, horizontal load support, securing of horizontal movement, and the amount of rotation due to deflection of the girder in one support. In order to provide all functions such as securing, the bearing dimensions have become large, and it has become uneconomical, including the girder structure.

  Against this background, a function-separated type bearing has been developed to reduce the size and cost of rubber bearings, and the number of adoption has been increasing since it was described in the revision of the road bridge bearing manual in 2004. . The function separation type bearing is a general term for a bearing system in which a function for supporting a vertical force and a function for supporting a horizontal force in an earthquake are separated.

  With regard to the function-separated type bearing, for example, in Patent Document 1, a sliding bearing that supports the vertical load so that the upper structure can move in the horizontal direction, and a horizontal bearing without supporting the vertical load of the upper structure. A horizontal load support mechanism that supports the horizontal load of the superstructure by shear deformation in all directions.The horizontal load support mechanism is fixed to the upper surface of the lower structure, and a gap is formed between the upper structure and the upper structure. An elastic body having a square flange plate to be formed, and fixed to the lower surface of the superstructure, engageable with the circumferential surface along the bridge axis direction and the bridge axis perpendicular direction of the flange plate, and a gap in the lower surface of the flange plate A function-separated bridge support device is disclosed that includes an engagement member that can be engaged via the engagement member and that also supports a lifting force.

  Non-Patent Document 1 discloses the features, merits, types, and points to be noted when adopting the function-separated type support.

  As shown in Non-Patent Document 1, (a) When a steel bearing is used as a vertical bearing, since the vertical rigidity is high and there is no sinking due to a live load, the occurrence of vibration can be suppressed. (b) Since the horizontal bearings do not support vertical loads, the shape is not determined by the vertical loads like the rubber bearings described above, the degree of freedom in design is increased by downsizing, and the horizontal rigidity is set freely. Although there is an advantage that the natural period of the bridge can be adjusted arbitrarily, the height of the vertical bearing is reduced, so that the space under the girder becomes narrower, and there are multiple vertical and horizontal bearings. The problem that the working space is narrowed due to the installation of the bearings has surfaced.

  In particular, for the vertical type concrete reaction wall type, (1) Since there is no stopper in the horizontal bearing, movement cannot be restricted until the completion of the concrete reaction wall, (2) Horizontal bearing to the concrete reaction wall Anchor bolt type is often used as the fixing method of the wall, but cracks may occur in the concrete reaction wall because the horizontal bearing moves due to the temperature expansion and contraction of the girder. (3) To construct the concrete reaction wall The problem that it takes time and money is becoming clear.

  On the other hand, in the Great East Japan Earthquake that occurred in March 2011, many bridges were damaged, and damages such as damage to support side blocks and damage to steel brackets for displacement limiting structures have been reported. In particular, bridges that have undergone earthquake-resistant measures are considered to have been damaged, and there is an urgent need to revisit them in preparation for a huge earthquake such as the Nankai Trough earthquake that is expected in the future.

  In addition, regarding the problem of the conventional function-separated type bearing as described above, in addition to this, a reaction force (horizontal load) equivalent to the horizontal force of the superstructure is transmitted to the substructure in the bridge. In order to cope with such a large earthquake of level 2 or higher, it is necessary to increase the size of the reaction wall or the lower structure or to reinforce it so as to have a corresponding strength. However, these measures cause a problem that much labor and cost are required for construction more than ever.

  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 girder The vertical load support mechanism and the horizontal load support mechanism are separated by interposing a rod-shaped damping member that suppresses vibration in the member axial direction between the fixed column and the main girders on both sides of the fixed column with respect to the horizontal load. The main girder is provided with a joint for supporting and fixing the rod-shaped damping member on the main girder, and the horizontal load supporting member consisting of a pair of rod-shaped damping members symmetrically about the fixed column is perpendicular to the bridge axis Horizontally arranged in the direction, one end of the rod-shaped damping member is attached to the fixed column, the other end is fixed to the joint provided on the main girder, and the horizontal load from the upper structure is reduced by the horizontal load support member to lower structure Developed a segregated function damping structure for bridges That.

  In the structure disclosed in Patent Document 2, it is possible to reduce the horizontal load, and accordingly, the lower work reaction force is also reduced, so there is no need to increase the size of the lower structure, or due to steel sheet winding or the like The advantage that substructure reinforcement is unnecessary is obtained, and reinforcement work against large-scale earthquake motion can be performed efficiently.

Japanese Patent No. 3634288 Japanese Patent Laying-Open No. 2015-031046

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

  In a bridge, there may be a relative movement in the direction of the bridge axis between the upper structure and the lower structure due to seismic motion, traffic vibration or thermal elongation.

  On the other hand, in Patent Document 2 described above, the end of the rod-shaped damping member is provided 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 a connecting bolt to be tightened slides in the direction of the bridge axis along a long slot for sliding provided in a connecting plate for attaching to the fixed column side.

  However, the provision of the sliding mechanism impairs the integration of the rod-shaped damping members, and when the connecting plates are slid in the sliding direction only with the connecting bolts, the connecting plates are not connected. The original width cannot be maintained, the rod-like damping members on both sides sandwiching the fixed column are broken in the linear positional relationship (see FIG. 10), and the original function as a horizontal load support mechanism may be partially impaired. .

  In addition, it is designed so that the lifting force and horizontal movement restrictions can be dealt with by side blocks provided in the main girder support, but it is a rod-shaped damping member against horizontal load in the event of a level 2 earthquake. In order to function, it is necessary to be able to move in the horizontal load direction. As a design condition for horizontal movement, as a displacement restraint function at all times and in the horizontal direction during a level 1 earthquake In the fixed state and level 2 earthquake, it is necessary to be able to move horizontally so that the rod-shaped damping member can exhibit the damping function.

  In other words, the side blocks, etc. should always function in response to upper positive forces and horizontal movement restrictions, but they must be designed so that they do not function during level 2 earthquakes. As a result, the function to suppress the function is lost, so that it becomes necessary to supplement the function separately. This leads to an increase in the size of the bearing and impairs the significance of the function separation type bearing.

  On the other hand, it is conceivable that a mechanism for suppressing the lifting force against level 2 or higher earthquake motion is separately incorporated between the lower structure and the upper structure. There is a problem of following with respect to the relative movement in the horizontal direction, such as engagement with the mold support.

  The present invention is a function-separated type damping structure in which a rod-shaped damping member is interposed between a fixed column and main girders on both sides of the fixed column with respect to a horizontal load. The purpose of the present invention is to provide a bridge-function-separated vibration control structure in which the vibration member can follow the movement of the superstructure in the direction of the bridge axis, and further has an efficient lifting force suppression mechanism using a fixed column. .

  The present invention provides the lower structure of the bridge in addition to the support for supporting the vertical load from the main girder of the upper structure, in addition to the fixed columns located between the main girders. In the function-separated vibration control structure for a bridge in which the vertical load support mechanism and the horizontal load support mechanism are separated by interposing a rod-shaped vibration suppression member that suppresses vibration in the member axial direction between the fixed column and the both sides thereof The rod-shaped damping members are connected via a connecting plate in a state allowing relative movement in the bridge axis direction, and the connecting plates located on both sides of the fixed column are integrated via a fixing member. The linear positional relationship between the rod-shaped damping members on both sides of the fixed column is maintained with respect to the relative movement of the bridge lower structure and the upper structure in the bridge axis direction. is there.

  In the function-separated vibration control structure with a horizontal load support mechanism separated from the vertical load support mechanism, it is possible to reduce the horizontal load. There is a merit that it is not necessary to increase the size or that there is no need to reinforce the substructure by winding a steel plate, and the reinforcement work for large-scale earthquake motion 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 it to the lower structure. Examples of the rod-shaped damping member include a buckling restrained brace, a friction damper, and an oil damper. By using these rod-shaped damping members, the bridge structure can be easily damped by reducing the horizontal load from the upper structure and transmitting it to the lower structure without enlarging or reinforcing the lower structure. Can also provide earthquake resistance.

  Among these, buckling-restrained braces were developed as sacrificial members for structures, and when large-scale earthquake motions act on the structures, the areas where the brace core material is plastically deformed to absorb seismic energy, A rod-like vibration damping device capable of damping control, for example, Japanese Patent Application Laid-Open No. 2012-013157, Japanese Patent Application Laid-Open No. 2003-193699, Japanese Patent Application Laid-Open No. 2001-214541, and Japanese Patent Application Laid-Open No. 2000-027293. Etc. are mentioned. By using this as a rod-shaped damping member of the present invention, even when a large-scale earthquake of level 2 or higher occurs, the effect of absorbing seismic energy by concentrating member damage on this buckling restrained brace can be obtained. .

  The member length of the rod-shaped damping member is determined by the space where the abutment or pier can be installed. For example, in the case of a two-main girder bridge, the length required for the joint of each main girder and the width of the fixed column are deducted. It becomes half. In the function-separated type damping structure of the present invention, the rod-like damping member (horizontal load) is placed on the upper part of the intermediate lower structure in the direction perpendicular to the bridge axis between the main girders that face each other in parallel with each other in the bridge axis direction. 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 damping members (horizontal load support members) are strong and have a structure that can be installed horizontally and symmetrically about the fixed column. . For example, there are an H shape mainly composed of an H-shaped steel, and a rectangular tube shape using a square steel pipe. The cross-sectional dimension of the fixed column is determined by the bending strength from the superstructure. For example, when the rod-shaped damping member is installed at a position where the yield axial force is 500 kN and the installation height is about 500 mm, the cross-sectional height is about 500 mm. is there.

  In the function-separated vibration damping structure of the present invention, the main girder of the bridge is provided with a joint for supporting and fixing the rod-shaped damping member, and is composed of a pair of rod-shaped damping members symmetrically about the fixed column. A horizontal load support member is disposed horizontally in a 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.

  By arranging the horizontal load support member horizontally in the direction perpendicular to the bridge axis, it is possible to obtain an effect that the horizontal load from the upper structure is 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 symmetrically about the fixed column, the transmission of the horizontal load from the upper structure is caused by the tension by one rod-shaped damping member and the compression by the other rod-shaped damping member. Are carried out simultaneously, the transmission of the horizontal load to the substructure is reduced.

  In this way, a pair of rod-shaped damping members are provided symmetrically in the transmission portion from the upper structure to the lower structure, and the tensile load and the compressive load are received at the same time, so that the horizontal load support member (horizontal load support mechanism) Strength is increased, and it is possible to efficiently give earthquake resistance to bridges without increasing the size of the substructure or remarkably reinforcing it.

  The joint is a portion provided on the main girder of the bridge for supporting and fixing the rod-shaped damping member. For example, when the joint is a friction joint, a high strength is attached so that the attachment plate can be attached. It is a portion made of a steel member having a structure in which a gusset plate provided with bolt holes is installed.

  In such a configuration, in the present invention, the fixed column and the rod-shaped damping members on both sides thereof are connected to each other via a connecting plate so as to allow relative movement in the bridge axis direction, and are positioned on both sides of the fixed column. By integrating the connecting plates through a 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 and upper structures in the bridge axis direction. To be maintained.

  As a structure that allows the relative movement in the bridge axis direction while connecting the fixed pillar and the rod-shaped damping members on both sides thereof via the connecting plate, for example, as described in Patent Document 2 described above, the fixed pillar or A long hole formed in the connecting plate extending in the direction of the bridge axis is formed, and provided at the end of the fixed column and the rod-shaped damping member with a rod-shaped tension material that penetrates the long hole and fastens the connecting plates on both sides. There is a structure in which the connecting plate is connected so that the tension material 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 original width, so that they slide sufficiently smoothly at the fixed column position. As shown in FIG. 9, which will be described in detail later, the rod-like damping members on both sides sandwiching the fixed column cannot maintain a linear positional relationship, and the original function as a horizontal load support mechanism May be partly damaged.

  On the other hand, in the present invention, the connecting plates positioned on both sides of the fixed column are integrated with each other through the fixing member, so that the connecting plates can maintain the original width, and the bridge lower structure The relative position in the bridge axis direction of the superstructure is maintained so that the linear positional relationship between the rod-shaped damping members on both sides of the fixed column is maintained, so that the original function as a horizontal load support mechanism is not impaired. It is a thing.

  One form of the fixing member for integrating the connecting plates located on both sides of the fixed column is to use a plate-like 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 parts on the connecting plate and plate-like fixing member and bolting them together, or by welding the connecting plate and plate-like fixing member to make a rigid connection, the rod-like restraints on both sides of the fixed column are fixed. The linear positional relationship between the vibrating members is maintained.

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

  In order to smoothly follow the movement of the superstructure in the direction of the bridge axis, it is desirable that the fixed columns and the connecting plates on both sides do not adhere to each other, but rather a slight gap is generated. As such, use a width holding pipe that holds the interval between the connecting plates on both sides across the fixed column and a bar-shaped tension member that penetrates the width holding pipe and is tightly connected to the connecting plates on both sides. Can do.

  By using a steel pipe or the like for the width holding pipe, when the connecting plates on both sides are tightened with a tension material passed through the width holding pipe, 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 eased, and the superstructure moves in the bridge axis direction. It can be made to follow smoothly.

  The fixing member of each form described above can be used alone or in combination of two or more according to conditions.

  Furthermore, in the function-separated vibration control structure for a bridge according to the present invention, when a horizontal girder connecting the main girders is provided between the main girders, relative movement in the vertical direction is performed between the fixed column and the cross girder. An upper lift resistance mechanism for restraining can be provided.

  The upper lift resistance mechanism is also preferably a structure that can follow the movement of the upper structure in the direction of the bridge axis. For example, a plate that straddles the upper end of the fixing column as the fixing member described above and connects and fixes the connecting plates on both sides. When a plate-like member is used, the plate-like member and the cross beam are joined via a steel material having a predetermined rigidity, and a stiffening member is attached to the cross beam as necessary. The lift resistance mechanism can be easily formed. For example, when the structure is such that the side block of the support portion does not work against level 2 or higher earthquake motion, it can function as an effective upper lift resistance mechanism.

  The function separation type vibration control structure of the bridge according to the present invention can be easily constructed and can effectively reduce the horizontal load from the upper structure and transmit it to the lower structure. In addition to the effect of being able to reduce and effectively giving 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 members. In a state where the linear positional relationship of the rod-shaped damping members on both sides of the fixed column is maintained, it is possible to follow the movement of the superstructure in the bridge axis direction, and to fully exhibit the function of the rod-shaped damping member it can.

  Furthermore, by providing an upper lift resistance mechanism that restrains the relative movement in the vertical direction between the fixed column and the cross beam, the fixed column for constructing the function-separated vibration control structure can It can also function as a lift resistance mechanism.

It is the perspective view which showed roughly an example of the function separation type | mold damping structure of this 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 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 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 resistance mechanism in the fixed pillar part. It is explanatory drawing which showed notionally the behavior when a level 1 earthquake motion acts on the function-separated type damping structure of this invention normally or. It is explanatory drawing which showed notionally the behavior at the time of a level 2 seismic motion acting on the function isolation | separation type damping structure of this invention. It is explanatory drawing which showed notionally the behavior at the time of a sudden earthquake motion acting on the conventional function-separated type damping structure. FIG. 10 is an explanatory diagram conceptually showing the case of the function-separated vibration damping structure of the present invention in contrast to FIG. 9.

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

  FIG. 1 schematically shows an example of a function-separated vibration damping structure of the present invention. The bridge 1 in this example has a main girder 6 and 6 in the direction of the bridge axis, a horizontal girder 3 in the direction perpendicular to the bridge axis, a floor slab 2 installed on these, etc. An upper structure 4 is provided.

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

  A fixed column 7 for supporting the rod-shaped damping members 8 and 8 is provided on the upper portion of the intermediate lower structure 5 in the direction perpendicular to the bridge axis between the main girders 6 and 6 arranged parallel to each other in parallel with each other in the bridge axis direction. Each main girder 6 is provided with a joint portion 9 for supporting and fixing the rod-like damping member 8, and a horizontal load supporting member comprising a pair of rod-like damping members 8 and 8 is symmetrical with respect to the fixed column 7 as a bridge. The rod-shaped damping members 8 are disposed horizontally in the direction perpendicular to the axis, and one end of each rod-like 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 composed of H-section steel, and is placed on the upper surface of the lower structure 5 (abutment / pier). Further, the joint portion 9 is intended to be integrated with the upper structure 4 and is made of a steel plate, a high-strength bolt, or the like, and is provided on the side surface of each main beam 6 in this example.

  Then, the horizontal load from the upper structure 4 is reduced by the horizontal load support member and transmitted to the lower structure 5. Specifically, for example, when the bridge 1 is shaken 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 upper structure 4 is maintained as it is. These loads can be reduced without transmitting to the lower structure 5.

  In such a structure, as shown in FIG. 5, which will be described in detail later, the connecting plates 14 located on both sides of the fixed column 7 are integrated with each other through a fixed plate 41 as a fixed member, thereby fixing the fixed column 7. Tightening between the connecting plate 14 and the connecting plate 14 is reduced, and the linear vibrations between the rod-like damping members 8 and 8 on both sides of the fixed column 7 with respect to the relative movement of the bridge lower structure 5 and the upper structure in the bridge axis direction. The positional relationship is maintained, and an upper lift resistance mechanism 61 for restraining the relative movement in the vertical direction between the fixed column 7 and the cross beam 3 using the fixed plate 41 is provided. In a situation where the side block 13 resisting the upper lifting force at the position of the bearing 12 against the earthquake motion does not work, the upper lifting resistance function is exhibited.

  FIG. 2 shows an example of a rod-shaped damping member 8 using a buckling restrained brace. The buckling-restrained brace shown in the figure includes a load receiving portion made of a low yield point steel material having a cross-fin cross section, and a load receiving portion formed by forming a width dimension and a thickness of each fin larger than that of the load receiving portion by using a general steel material. The core member 21 includes an end member welded and fixed to one end of the load member 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 material 21, buckling prevention materials 22 made of angle steel having a width equivalent to the width of each fin of the end member of the core material 21 are disposed. The end member has a length straddling a part of the end member.

  A spacer having a thickness equivalent to the thickness of the fin of the end member is disposed outside each fin of the load receiving portion of the core member 21, and a part of the end member and the spacer are placed by the buckling prevention member 22. The assembly bolts 23 (high-strength bolts) and the assembly nuts are clamped and clamped together to assemble them integrally.

  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 bolt 23 is tightened, a gap is formed between the load receiving portion of the core material 21 and the buckling prevention material 22, and thus a tensile or compressive load is applied between the end members of the core material 21. When is applied, the load receiving portion undergoes tensile deformation or compression deformation. At this time, the buckling prevention member 22 allows the load receiving portion to change its length by the long hole 25 and acts so that the buckling prevention member 22 resists a load that the load receiving portion is 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. A buckling restrained 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 brought into surface contact with the fixed column main body (flange portion) during compression to transmit the load, and during tension, via a connecting bolt that penetrates the fixed column and tightly connects the connecting plates 14 on both sides. The top end hanging plate 15 at the upper end of the connecting plate 14 supports the weight of the rod-like damping member 8 on the fixed column, and the rod-like damping member 8 It plays a role of smooth movement in the direction perpendicular to the axis.

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

  Further, as shown in the figure, the connecting plate 14 is provided with a long slot 17 for sliding. The long slot 17 for sliding serves a role of moving in the bridge axis direction for following the movement of the superstructure in the bridge axis direction.

  Further, in the illustrated example, an extension portion is formed in the lower portion of the connecting plate 14 in the longitudinal direction of the bridge axis, and a tension bolt 52 that is passed through a width holding pipe 51 described later in the extension portion (see FIGS. 3, 4, and 6). Bolt holes 18 are provided for fixing the bolts.

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

  The fixed column 7 includes a base plate 29 and a fixed column main body made of H-shaped steel, which is placed and fixed on the base plate 29, and anchor bolts are attached to 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 H-shaped steel flange is provided with holes for passing the connecting bolts 27 in addition to the slide long holes 17 provided in the connecting plate 14.

  The attachment structure of the pair of rod-shaped damping members 8 and 8 (in this example, buckling restrained braces) to the fixed column 7 is as shown in the figure. That is, the rod-shaped damping member 8 having the sliding long hole 17 is fixed to the fixed column by overlapping the connecting plate 14 at the end of the rod-shaped damping member 8 on the flange of the H-shaped steel, which is the main body of the fixed column 7 7 is attached.

  As described above, the long slot 17 for sliding serves a function of moving in the bridge axis direction to follow the movement of the superstructure in the bridge axis direction. Specifically, for example, by installing a square nut 31 with a projection in a long slot 17 for sliding provided in the connecting plate 14, the long hole 17 becomes a guide rail, and the structure is movable in the following direction.

  In the present invention, in such a configuration, the coupling plates 14 located on both sides of the fixed column 7 are integrated with each other through a fixing member, thereby reducing the tightening between the fixed column 7 and the coupling plate 14. The horizontal load support is achieved by maintaining the linear positional relationship between the rod-like damping members 8 on both sides of the fixed column 7 with respect to the relative movement of the bridge lower structure 5 and the upper structure in the bridge axis direction. The original function as a mechanism is not impaired.

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

  In such a configuration, since the fixed plate 41 as the fixing member and the width holding pipe 51 hold an interval corresponding to the length of the width holding pipe 51 between the connecting plates 14 and 14 on both sides, the width holding pipe 51 By making the length of the column not less 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 eased and the superstructure can smoothly follow the movement in the bridge axis direction. Can do.

  FIG. 4 shows the details when the fixed column is fixed to the upper side surface of the lower structure. In this example, the fixed column 7 includes a fixed column main body made of H-shaped steel and two fixed plates 32 and 32 having holes for passing anchor bolts 30. The H-shaped steel flange has a hole for allowing the connecting bolt 27 to pass along with the slide long hole 17 provided in the connecting plate 14, and the H-shaped steel web has a hole for allowing the anchor bolt 30 to pass. Each is provided.

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

  The mounting structure of the pair of rod-like damping members 8 and 8 (in this example, buckling-restrained braces) to the fixed column 7 is the same as 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 through the fixed plate 41, and further, between the fixed column 7 and the cross beam 3 using the fixed plate 41. An upper lift resistance mechanism 61 that restrains the relative movement in the vertical direction is provided.

  In this example, the width holding pipe 51 and the tension bolt 52 used in the embodiment 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 shown in FIG. It becomes.

  By integrating the connecting plates 14 and 14 via the fixed plate 41, the tightening between the fixed column 7 and the connecting plate 14 is eased, and the bridge lower structure 5 and the upper structure in the direction of the bridge axis are relaxed. With respect to the movement, it is possible to smoothly follow the relative movement in the direction of the bridge axis while maintaining the linear positional relationship between the rod-like damping members 8 and 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 connection plate 62 having the upper and lower connection plates is bolted to the fixed plate 41, and the upper connection portion 62 is connected. 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 where the stress of the connecting block 62 is transmitted.

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

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

  FIG. 7 shows the behavior when a level 1 earthquake motion is applied to the function-separated damping structure of the present invention at all times or FIG. 8 conceptually shows the behavior when a level 2 earthquake motion acts on the function-separated damping structure of the present invention. It is shown as an example.

  For normal or level 1 ground motion, the bearing receiving the main girder bears the vertical vibration as shown in Fig. 7, and the bearing is also fixed in the uplift force. Can be resisted by the stopper function of the position side block.

  With respect to relative movement in the direction of the bridge axis due to normal thermal elongation, the fixed column position can follow the displacement as described above.

  In Fig. 8 (a), the superstructure is greatly displaced in the horizontal right direction in the figure due to the earthquake motion of level 2 or higher, the tensile axial force acts on the right-hand bar-shaped damping member being fixed, and the left-hand bar-like damping member is compressed. It shows how the axial force acts.

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

  Similarly, in Fig. 8 (b), the superstructure is greatly displaced in the horizontal left direction in the figure due to the earthquake motion of level 2 or higher, and the tensile axial force acts on the fixed rod-like damping member on the right side, and the rod-like damping member on the left side. Fig. 8 shows how the compression axial force acts. While the states of Fig. 8 (a) and Fig. 8 (b) are repeated, the vibration in the horizontal direction is attenuated by the absorption of the vibration energy by the rod-shaped damping member. .

  FIG. 9 conceptually shows the behavior when a sudden seismic motion is applied to the conventional function-separated vibration control structure, and FIG. 10 is a diagram of the function-separated vibration control structure of the present invention in contrast to FIG. The case is shown conceptually.

  As described above, in the structure of FIG. 9A in which the connecting plates 14 and 14 on both sides of the fixed column 7 are fastened together with the connecting bolt 27 and the connecting plate 14 is directly pressed against the fixed column 7, the connecting bolt 27 Even if it is configured to slide along the long slot for sliding, it is difficult to follow the movement of the superstructure in the direction of the bridge axis sufficiently, as shown in FIG. The damping members 8, 8 are not in a straight line but have a bent angle, and the function of the rod-like damping member 8 may not be sufficiently exhibited.

  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 a fixing member 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 obtained. Since it is possible to follow the relative movement of the superstructure while maintaining the linear positional relationship between the vibration members 8 and 8, the function of the rod-shaped vibration damping member 8 can be sufficiently exhibited.

DESCRIPTION OF SYMBOLS 1 ... Bridge, 2 ... Floor slab, 3 ... Cross girder, 4 ... Superstructure, 5 ... Bottom structure, 6 ... Main girder, 7 ... Fixed column, 8 ... Bar-shaped damping member, 9 ... Main girder side junction,
DESCRIPTION OF SYMBOLS 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 ... Connecting bolt, 28 ... Height-adjusting mortar, 29 ... Base plate, 30 ... Anchor bolt, 31 ... Slotted square nut, 32 ... Fixed plate 41 ... Fixed plate,
51 ... Width retaining pipe, 52 ... Tension bolt,
61 ... Uplift resistance mechanism, 62 ... Connection block, 63 ... Stiffening member, 64 ... Stiffening member

Claims (5)

  In the lower structure of the bridge, in addition to the support that supports the vertical load from the main girder of the upper structure, a fixed column located between the main girders is provided, and the member axis between the fixed column and the main girder on both sides thereof is provided for horizontal load In the function separation type 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 damping member that suppresses vibrations in the direction, the fixed column and the rod-shaped damping on both sides thereof The members are connected via a connecting plate in a state allowing relative movement in the direction of the bridge axis, and the connecting plates located on both sides of the fixed column are integrated with each other through the fixing member, thereby The functional separation type control of the bridge is characterized in that the linear positional relationship between the rod-shaped damping members on both sides of the fixed column is maintained with respect to the relative movement of the lower structure and the upper structure in the bridge axis direction. Shaking structure.   2. The function separation type vibration damping structure for a bridge according to claim 1, wherein the fixed columns and the connection plates on both sides penetrate the long holes formed in the fixed columns or the connection plates and extend in the bridge axis direction. It is connected with a bar-like tension material that binds the connecting plates together, and the tension material can slide along the long hole with respect to the relative movement of the bridge lower structure and the upper structure in the bridge axis direction. A segregated function-damping structure for bridges.   3. The function separation type vibration damping structure for a bridge according to claim 1, wherein at least one of the fixing members is a plate-like member that straddles the upper end of the fixing column and connects and fixes the connecting plates on both sides. A segregated function-damping structure for bridges.   The function separation type vibration damping structure for a bridge according to claim 1, 2, or 3, wherein at least one of the fixing members spans the fixing column and holds a gap between the connecting plates on both sides, A function-separated type vibration damping structure for a bridge, comprising a bar-like tension member penetrating a width maintaining pipe and tightly connecting the connecting plates on both sides.   In the function-separated type vibration damping structure for a bridge according to any one of claims 1 to 4, a cross beam connecting between the main beams is provided between the main beams, and the fixed column, the cross beam, A function separation type vibration damping structure for a bridge, characterized in that an uplift resistance mechanism for restraining relative movement in the vertical direction is provided in between.