JP3911673B2 - Seismic control structure of ramen viaduct - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a viaduct damping structure that maintains the seismic performance of a ramen viaduct without providing underground beams.
[0002]
[Prior art]
Conventionally, the ramen viaduct 1 maintains the earthquake resistance performance by connecting the piers 3 with underground beams. However, when the underground beam is provided, in addition to the construction of the pier, it is necessary to excavate the ground around the pier, which causes problems such as a longer construction period and an increased cost.
Therefore, for the purpose of eliminating the underground beam, as shown in FIG. 3, the ramen viaduct 1 is supported by the pier 3 and the pier 3 in a direction allowing deformation in the direction perpendicular to the bridge axis. A seismic control device 11 is arranged so as to connect the superstructure 7 to absorb the energy at the time of the earthquake.
[0003]
[Problems to be solved by the invention]
When a seismic response analysis was performed on the representative cross section of the ramen viaduct 1 equipped with such a vibration control device 11 using the presence or absence of underground beams and the presence or absence of the vibration control device as parameters, as shown in FIG. It was found that the bending curvature increases at the upper part of the pier 3 in any case. By the way, although the said damping device 11 will show the damping effect more by installing in the site | part with a large bending curvature, as FIG. 4 also shows, the ramen viaduct 1 which provided the damping device 11 is shown. It can be seen that the pier 3 has a smaller bending curvature than the others and does not fully utilize the function of the vibration control device 11.
[0004]
In view of the above circumstances, an object of the present invention is to provide a viaduct damping structure that has good workability and maintains the seismic performance of a ramen viaduct at low cost.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, the seismic control structure for the ramen viaduct includes a lower end portion of the superstructure of the ramen viaduct and a predetermined pier made of reinforced concrete. It is provided so as to connect the side surface of the height, and the bridge pier uses a torsional reinforcing bar as a main reinforcement extending from the upper end portion to the vicinity of the upper portion of the predetermined height , and the vibration control device is a surface. A first plate member and a second plate member arranged in parallel with each other facing each other, and a viscoelastic body disposed so as to be sandwiched between the first plate member and the second plate member, The plate material is arranged so as to stand in the vertical axis direction with the surface facing the direction perpendicular to the bridge axis, and one end portion is fixed to the lower end portion of the superstructure, and the second plate material is attached to the pier A side surface having a predetermined height and parallel to a surface in the vicinity of the other end of the first plate member. It is characterized by being secured to so that.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the vibration control structure of the ramen viaduct of the present invention will be described in detail with reference to FIGS. The present invention forms a part with low bending rigidity at the upper part of the pier that constitutes the ramen viaduct, and provides a seismic control device connected to the superstructure that constitutes the viaduct on the side of this part, thereby improving the efficiency of the seismic control function. It aims to make it easier.
[0008]
As shown in FIG. 1, the ramen viaduct 1 is composed of a substructure 2 including a support pile 4 and a pier 3, and a superstructure 7 including a floor slab 8, a main girder 9, and a cross girder 10. As shown in FIG. 2, the pier 3 is composed of a reinforced concrete structure including a main reinforcement 5 a, a main reinforcement 5 b, a band reinforcement 5 c, and concrete 6.
Moreover, the support pile 4 which supports this pier 3 is comprised by the reinforced concrete structure or concrete filling steel pipe structure etc. similar to the pier 3, The said pier 3 is distribute | arranged coaxially with the support pile 4, and both are rigid. It is joined to. As described above, the substructure 2 is configured such that the pier 3 is directly supported by the support pile 4, and no underground beam connecting the pier 3 is provided.
[0009]
On the other hand, as shown in FIG. 1, the main girder 9 and the horizontal girder 10 provided in the superstructure 7 connect the piers 3 in which the main girder 9 is arranged in parallel with a predetermined distance in the bridge axis direction. At the same time, the cross beam 10 connects the bridge piers 3 arranged in pairs with a predetermined distance in the direction perpendicular to the bridge axis. These are both disposed at the upper end of the pier 3 and are provided so that the main reinforcement 5a constituting the pier 3 protrudes upward, and the protruding main reinforcement 5a is accommodated inward so that the reinforced concrete structure is formed. By constructing the main girder 9 and the cross girder 10, the pier 3 and the main girder 9 and the cross girder 10 are rigidly joined. The floor slab 8 is arranged so as to be supported by the main girder 9 and the horizontal girder 10 having such a configuration, and the upper work 7 is configured.
[0010]
By the way, as shown in FIG. 2, the bridge pier 3 used here is provided with a torsional reinforcing bar in the main reinforcing bar 5a extending from the upper end portion to the vicinity of the upper portion of the predetermined height 3a, and has a predetermined reinforcing bar 5b made of bar steel. Compared to the main body of the bridge pier 3 extending from the vicinity of the upper portion of the height 3a to the lower end portion, the bending rigidity is reduced. This is performed for the purpose of guiding a plastic hinge near the upper part of the predetermined height 3a where the seismic control device 11 is provided later. When the seismic force in the direction perpendicular to the bridge axis acts on the upper work 7, the predetermined height is increased. In the vicinity of the upper portion of the slab 3a, stress can be concentrated on the portion where the main bar 5b made of steel bar changes to the main bar 5a made of torsional reinforcing bars, and the plastic hinge can be guided, and the bending curvature in the vicinity of the predetermined height 3a of the pier 3 increases. It is.
The main reinforcement 5a and the main reinforcement 5b of the pier 3 are, for example, a set of two, and the main reinforcement 5b extending from the vicinity of the upper portion of the predetermined height 3a to the lower end portion is arranged on a straight line, and the upper portion of the predetermined height 3a. For the main reinforcing bar 5a extending from the vicinity to the upper end portion, it is conceivable to form a twisted reinforcing bar by knitting these two reinforcing bars. In this way, the number of main bars 5a and main bars 5b, the arrangement configuration thereof, and the like are not particular, and any may be used as long as the main bar 5a is formed as a torsional bar having lower bending rigidity than the main bar 5b. .
[0011]
The reinforced concrete ramen viaduct 1 described above is provided with a vibration control device 11 corresponding to a horizontal force acting in a direction perpendicular to the bridge axis when an earthquake occurs. As shown in FIG. 2, the vibration control device 11 used in the present embodiment includes a first plate member 12, a second plate member 13, and a viscoelastic body 14, and the first plate member 12, and The second plate member 13 is made of a plate material such as a highly rigid steel material that is not easily deformed by an external force, and the viscoelastic body 14 is a material having damping performance such as asphalt, synthetic rubber, acrylic resin, silicone, or the like. Is used. The first plate member 12 and the second plate member 13 are arranged in parallel with the surfaces facing each other, and the viscoelastic body 14 is filled so as to fill the gap between the two, so that the vibration control device 11 is Composed. When the first plate member 12 and the second plate member 13 are relatively displaced in the plane due to the occurrence of an earthquake or the like, the vibration control device 11 is subjected to vibration energy by the viscous resistance force generated in the viscoelastic body 14 sandwiched therebetween. It absorbs.
[0012]
In the present embodiment, as shown in FIG. 1, the second plate member 13 has a predetermined height 3 a of the pier 3 such that one surface 13 a faces the direction perpendicular to the bridge axis of the ramen viaduct 1. The other surface 13b is fixed to the side surface via fixing means. Further, the first plate member 12 has a long member length and has a length that reaches the predetermined height 3a of the bridge pier 3 from the lower end portion of the superstructure 7, and faces the second plate member 13 face to face. At the same time, it is arranged so as to stand in the vertical direction, and one end 12 a is fixed to the lower end surface of the main girder 9 constituting the upper work 7. As a result, the surface in the vicinity of the other end portion 12b of the first plate member 12 and the one surface 13a of the second plate member 13 face each other, and the viscoelastic body 14 is filled in the gap between the two, thereby controlling the surface. A seismic device 11 is configured.
[0013]
Thus, in the present embodiment, the main reinforcing bar 5a extending from the upper end of the pier 3 to the vicinity of the upper part of the predetermined height 3a to which the second plate member 13 of the vibration control device 11 is fixed is a torsional reinforcing bar, and the main reinforcing bar made of bar steel. It was set as the structure with low bending rigidity compared with the pier 3 from the upper part vicinity of the predetermined height 3a provided with 5b to a lower end part. As a result, when an earthquake or the like occurs and a horizontal force acts in the direction perpendicular to the bridge axis of the ramen viaduct 1, the pier 3 has a plastic hinge in the vicinity where it changes from a main bar 5b made of steel bar to a main bar 5a made of torsional reinforcement. Occurs, and the bending curvature in the vicinity of the predetermined height 3a of the pier 3 increases. Thereby, although the bridge pier 3 retains the bearing strength for supporting the superstructure 7, the pier 3 above the predetermined height 3a is deformed following the superstructure 7, and the bending curvature is increased accordingly. In the vibration control device 11 provided at the height 3a, the first plate member 12 and the second plate member 13 are also relatively displaced in the direction perpendicular to the bridge axis in the plane, and the viscoelastic body 14 sandwiched between them has a viscous resistance. Force is generated and vibration energy is effectively absorbed, and the vibration of the ramen viaduct 1 is attenuated to ensure safety.
[0014]
This embodiment is merely an example, and it goes without saying that any form can be adopted without being limited to the present embodiment unless departing from the gist of the present invention.
[0015]
According to the above-described configuration, the torsion bar is used for the main reinforcement 5a extending from the upper end portion of the pier 3 of the ramen viaduct 1 to the vicinity of the upper portion of the predetermined height 3a, and at the predetermined height 3a of the pier 3, The connected vibration control device 7 was fixed. As a result, when an earthquake or the like occurs, the plastic hinge can be guided near the upper portion of the predetermined height 3a of the pier 3 and the vibration control device 11 is provided near the plastic hinge occurrence location. The seismic control performance of the seismic device 11 can be improved, and the seismic performance of the ramen viaduct 1 can be improved without the use of underground beams. It is possible to greatly contribute to the reduction of construction costs.
[0016]
The ramen viaduct 1 uses a vibration control device 11 composed of a first plate member 12, a second plate member 13, and a viscoelastic body 14, so that the workability is good with a simple structure and the construction period is shortened and the construction cost is reduced. It is possible to greatly contribute to
[0017]
【The invention's effect】
According to the vibration control structure of the ramen viaduct according to claim 1, the vibration control device arranged so as to be freely deformable in the direction perpendicular to the bridge axis includes the lower end of the superstructure of the ramen viaduct and the pier made of reinforced concrete. When the occurrence of an earthquake or the like, the bridge pier uses a torsional reinforcing bar for the main reinforcement that extends from the upper end to the vicinity of the upper part of the predetermined height. Can guide the plastic hinge in the vicinity of the upper part of the predetermined height of the pier, and because the structure is provided with a vibration control device at the location where the plastic hinge is generated, it becomes possible to improve the vibration control performance of the vibration control device, It is possible to improve the seismic performance of the ramen viaduct without providing underground beams, and it has a simple structure and good workability, and can greatly contribute to shortening the construction period and cost.
[0018]
In addition, the vibration control device is disposed so as to be sandwiched between the first plate member and the second plate member, and the first plate member and the second plate member arranged in parallel with the faces facing each other. Comprising a body, the first plate is arranged so as to stand in the vertical axis direction with the surface facing the direction perpendicular to the bridge axis, and one end is fixed to the lower end of the upper work, Since the second plate material is fixed to the side surface of the predetermined height of the pier so as to be parallel to the vicinity of one end of the first plate material, the workability is good with a simple configuration and the work period is shortened. It is possible to greatly contribute to the reduction of construction costs.
[Brief description of the drawings]
FIG. 1 is a diagram showing a seismic structure of a ramen viaduct according to the present invention.
FIG. 2 is a view showing a mounting part of a vibration control device for a ramen viaduct according to the present invention.
FIG. 3 is a view showing a conventional vibration control structure of a ramen viaduct.
FIG. 4 is a diagram showing the maximum deformation when an earthquake occurs on a conventional ramen viaduct.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ramen viaduct 2 Substructure 3 Bridge pier 3a Predetermined height 4 Support pile 5a Main reinforcement 5b Main reinforcement 5c Band reinforcement 6 Concrete 7 Superstructure 8 Floor slab 9 Main girder 10 Cross girder 11 Damping device 12 First plate 12a One end 12b The other end 13 Second plate 13a One surface 13b The other surface 14 Viscoelastic body

Claims (1)

A vibration control device arranged so as to freely deform in the direction perpendicular to the bridge axis is provided to connect the lower end of the superstructure of the ramen viaduct and the side surface of the bridge pier made of reinforced concrete. And
The bridge pier uses a torsional reinforcing bar for the main reinforcement from the upper end to the vicinity of the upper part of the predetermined height ,
The vibration control device includes a first plate member and a second plate member arranged in parallel with each other facing each other, and a viscoelastic body arranged so as to be sandwiched between the first plate member and the second plate member. Prepared
The first plate is arranged so as to stand in the vertical axis direction with the surface facing the direction perpendicular to the bridge axis, and one end is fixed to the lower end of the upper work,
A second plate member is fixed to a side surface of the pier at a predetermined height so as to be parallel to a surface near the other end of the first plate member.

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