JP4096534B2 - Bridge using external cable - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bridge using an external cable and a deflecting device used for a deflecting portion of the bridge.
[0002]
[Prior art]
FIG. 7 shows an example of a bridge using an external cable, which is a case of a PC box girder bridge by a cast-in-place method using an internal / external cable system. In the outer cable system, an outer cable 2 as a tension member subjected to permanent rust prevention treatment is disposed outside the concrete member of the main girder 1 and is permanently attached to the main girder 1 through a fixing part or a deflection part. It is a method to give stress.
[0003]
In the example of FIG. 7, two deflection portions 3 are provided between the fulcrum cross beams 4 and 4 in the inner space of the box girder, and the direction of the outer cable 2 is changed by the deflection portion 3 and the like to deflect the main girder 1 in the vertical direction. Giving power. Note that the fulcrum cross beam 4 is used as a deflection unit or a fixing unit. The inner cable 6 is disposed on the upper floor slab 1a and the lower floor slab 1c.
[0004]
Such an external cable type PC bridge has the following features: ( 1 ) Since the cable is placed outside the concrete, the thickness of the concrete member, especially the web 1b, can be reduced, and the weight can be reduced. ( 2 ) Concrete The installation work of the sheath in the member becomes unnecessary, and at the same time, there is less tension material in the cross section of the concrete, so it is easier to place the concrete, and the workability can be improved and the construction period can be shortened. ( 3 ) Internal cable It is possible to use a large-capacity tendon material compared to ( 4 ) Outer cables are easier to maintain and repair than inner cables, ( 5 ) Outer cables are higher than inner cables There are advantages such as being able to maintain the tension level.
[0005]
The deflection unit 3 has a deflection tube 5 through which the outer cable 2 passes, and is a portion that maintains the arrangement shape of the outer cable and transmits the deflection force to the main beam. It must be integrated with the main girder concrete so that there is no separation. The shape may be a concrete partition type or rib type, or a concrete block or steel projection type. Further, the deflection unit 3 and the members in the vicinity of the deflection unit must be reinforced so as to be sufficiently safe against the force acting from the outer cable 2.
[0006]
FIG. 8 shows an example of a concrete partition type deflecting section 3 in which a plurality of deflecting pipes 5 made of steel pipes are embedded in parallel on the left and right sides of the lower part of the rib 3a. Conventionally, a reinforcing reinforcing bar 50 that resists the deflection force (prestress component force P) of the outer cable is disposed around the deflection pipes 5 for reinforcement. That is, a part against the prestressing force component P bear a shear stress of the rib 3a and the web 1b, rises from the bottom slab 1c against local tensile force T ₁ of the vertical direction generated in the deflection Kanka side reinforced with rebar 50a, it is reinforced with rebar 50b penetrating horizontally with respect to the horizontal direction of the split裂引tension T ₂ that occurs in the upper deflection tube.
[0007]
[Problems to be solved by the invention]
However, in the case of the deflection part reinforcement structure by the conventional rebar as mentioned above, there are the following problems.
[0008]
(1) The deflection tube 5 needs to be installed at the position where the outer cable is disposed, but it is difficult to accurately install the plurality of deflection tubes 5 at predetermined positions.
[0009]
(2) With respect to the deflection force of the outer cable, it is necessary to arrange a large amount of reinforcing bars 50, and the assembling work becomes very complicated.
[0010]
(3) It is difficult to place concrete into the deflecting portion 3 in which a large amount of reinforcing bars 50 are arranged, and there is a high possibility of causing poor placement.
[0011]
The present invention has been made to solve such problems, and the purpose of the present invention is to enable accurate and easy installation of the deflection pipe during construction of the deflection section in an external cable type bridge having the deflection section. Another object of the present invention is to provide a PC bridge using an external cable that can reduce the amount of reinforcing bars arranged in the deflecting portion, facilitates assembly work, and can easily and reliably place concrete. .
[0012]
[Means for Solving the Problems]
Claim 1 of the present invention is an external cable system in which a tension member is arranged along the bridge axis direction outside the cross section of the member of the main girder, and prestress is applied to the main girder through the fixing portion and the deflection portion of the tension member. In the bridge, a deflection pipe embedded in the deflection portion and through which the tension material is inserted is attached to a reinforcing plate that intersects the axial direction of the deflection pipe, and a plurality of the reinforcing plates are arranged at intervals in the bridge axis direction, A bridge using an external cable, characterized in that the main body part through which the deflection pipe of each reinforcing plate is attached is embedded in the deflecting portion, and the end of each reinforcing plate is embedded in the concrete member of the main girder It is.
[0013]
In this claim 1, the outer cable method is a method in which the tension material is arranged by being deflected in the vertical direction outside the member cross section of the main girder, and includes the combined method of the inner cable and the outer cable, and the all outer cable method. Furthermore, a large eccentric outer cable system (extra-dosed bridge) in which the outer cable is eccentric beyond the range of the girder height is also included. Further, the present invention is applied to a concrete bridge, a mixed bridge of concrete and steel plate, a composite bridge, or the like.
[0014]
In the deflection portion of the outer cable type bridge according to claim 1, a deflection pipe through which the tension material is inserted is attached to a reinforcing plate that intersects the axial direction of the deflection pipe, and the reinforcing plate is spaced in the axial direction of the deflection pipe. It is possible to use a deflecting device that is arranged in a plurality of units and has a deflecting tube penetratingly attached to each reinforcing plate and unitized .
[0015]
In Claim 1 , the deflection part is a concrete partition type, rib type, or projection type, and a tension material (PC steel wire, PC steel strand, PC steel bar, fiber) is formed below or above the deflection part. Reinforcement plastic (such as reinforced plastic), that is, a reinforcing plate (steel plate, etc.) attached through the outer pipe deflection pipe (steel pipe, etc.) is placed, the body is embedded in the deflection section, and the end is in the concrete member of the main girder To be buried. This reinforcing plate is arranged vertically so as to be orthogonal to the bridge axis, and a plurality of reinforcing plates are arranged at a predetermined interval in the bridge axis direction, penetrated by the deflection pipe, fixed by welding or the like, and the deflection pipe unit. To do.
[0016]
Claim 2 of the present invention, the reinforcing plate, bridges of claim 1, characterized in that the reinforcing plate is displaced stop to achieve an body of the concrete of the deflecting unit and the main girder is provided It is.
[0017]
The stopper is a number of dowel holes drilled in the reinforcing plate, a number of stud gibbles protruding by welding or the like on the surface of the reinforcing plate, or irregularities formed by wave machining on the surface of the reinforcing plate. And integration of the deflection part and the concrete of the main girder.
[0018]
In the configuration as described above, when the main girder is manufactured, the deflection tube and the reinforcing plate are arranged in the deflecting portion, the deflecting tube is embedded in the concrete of the deflecting portion, and the reinforcing plate is embedded in the concrete of the deflecting portion and the main girder. To do. At the same time as the deflection pipe is disposed in the deflecting portion, the portion through which the outer cable of the deflecting portion passes and the main girder portion around the portion are reinforced by the reinforcing plate.
[0019]
Prestress is introduced into the main girder by inserting the outer cable through the deflection tube and fixing it to the fixing unit. A part of the prestress component force P acting on the deflecting portion by changing the direction of the outer cable is borne by the shear stress of the partition walls, ribs and web, and the local tensile force T ₁ in the vertical direction generated below the deflecting tube. On the other hand, it resists by the displacement of the integrated deflection tube and the reinforcing plate and the reinforcing plate, and the reinforcing plate resists the horizontal split tensile force T ₂ generated on the upper side of the deflecting tube (FIG. 1 (d)). See).
[0020]
Since the deflection tube of the outer cable can be attached to the reinforcing plate with high accuracy in advance at a factory or the like, installation of the deflection tube during construction of the deflection unit can be easily performed with high accuracy. In addition, by integrating the deflection pipe and the reinforcing plate and adding a stopper to the reinforcing plate, it is possible to use the reinforcing plate as a substitute for the reinforcing reinforcing bar of the deflecting portion, thereby reducing the amount of reinforcing bars disposed on the deflecting portion. And assembly work is facilitated. Furthermore, since the amount of reinforcing bars to be arranged is reduced, it is possible to easily and surely place concrete, and it is possible to construct dense concrete.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiment. This embodiment is an example in which the present invention is applied to a PC box girder bridge by a cast-in-place method using both internal and external cable systems. 1 to 3 show a first embodiment of the present invention. 4 to 6 show a second embodiment of the present invention.
[0022]
As shown in FIG. 1, a main girder 1 of a PC box girder bridge is composed of an upper floor slab 1a, a pair of left and right webs 1b, and a lower floor slab 1c. ) Is an external cable system. The deflection part 3 disposed between the fulcrum cross beams (not shown) of the main girder 1 is a concrete rib type, and a deflection pipe 5 made of a steel pipe and a hole are respectively provided on the left and right sides of the lower part of the rib 3a. A reinforcing plate 10 made of a steel plate is disposed.
[0023]
The reinforcing plates 10 are arranged vertically so as to be orthogonal to the bridge axis, and a plurality of reinforcing plates 10 are arranged at intervals in the bridge axis direction. Further, the reinforcing plate 10 is disposed such that the main body is embedded in the lower portion of the rib 3a, and the side end portion and the lower end portion are embedded in the lower floor slab 1c and the web 1b, respectively. As shown in FIG. 1 (a), the rib 3a is formed with a beam portion whose lower portion is thick in the bridge axis direction, and a reinforcing plate having a low height on both sides of the beam portion in the bridge axis direction. 10 and two high-strength reinforcing plates 10 projecting upward from the beam portion are disposed in the central portion.
[0024]
As shown in FIGS. 2 and 3, a number of deflection pipes 5 corresponding to the number of outer cables arranged on one side of the main beam are attached through a plurality of reinforcing plates 10. The deflection tube 5 and the reinforcing plate 10 are assembled with high precision by welding or the like at a factory or the like to form a deflection tube unit. The deflection tube 5 is a curved tube.
[0025]
Further, the reinforcing plate 10 is provided with a large number of dowel holes 10a, and the dowel holes 10a function as a stopper and are integrated with the concrete of the rib 3a, the web 1b, and the lower floor slab 1c. Note that the portion of the gibber hole 10a embedded in the web 1b and the lower floor slab 1c can also be used as an insertion hole for reinforcing bars arranged in the lower floor slab 1c and the web 1b.
[0026]
Next, in 2nd Embodiment of FIGS. 4-6, the reinforcement board 11 which consists of a steel plate with which the stud dowel 12 protruded is used. Other configurations are the same as those of the first embodiment shown in FIGS.
[0027]
The stud dowel 12 is fixed to both surfaces of the reinforcing plate 11 by resistance welding or the like, and the reinforcing plate 11 and the deflection tube 5 are assembled with high accuracy by welding or the like at a factory or the like to form a deflection tube unit.
[0028]
The means for preventing the displacement of the reinforcing plate is not limited to the illustrated example as described above, and may be irregularities formed on the surface of the reinforcing plate by wave processing or the like.
[0029]
In the configuration as described above, the main girder 1 is manufactured by a cast-in-place method (extrusion method, overhanging method, support construction, etc.), and when the main girder 1 is manufactured, the deflection pipe 5 and the reinforcing plate 10 or 11 are deflected. It arrange | positions in the part 3, the deflection | deviation pipe | tube 5 is embed | buried in the concrete of the rib 3a, and the reinforcement board 10 or 11 is embed | buried in the concrete of the rib 3a, the web 1b, and the lower floor slab 1c. At the same time as the plurality of deflecting tubes 5 are disposed on the rib 3a, the portion of the rib 3a through which the outer cable passes, the surrounding web 1b, and the lower floor slab 1c are reinforced by the reinforcing plate 10 or 11.
[0030]
Prestress is introduced into the main girder 1 by inserting the outer cable 2 through the deflection tube 5 and fixing it to a fixing part such as a fulcrum bridge girder. Part of the prestress component force P acting on the deflecting portion 3 by changing the direction of the outer cable 2 is borne by the shear stress of the rib 3a and the web 1b, and the local tensile force in the vertical direction generated below the deflecting tube. A horizontal split tension generated on the upper side of the deflection tube by resisting T ₁ by a plurality of integrated deflection tubes 5, the reinforcing plates 10 and 11, the diverging holes 10 a of the reinforcing plates 10 and 11, the stud diver 12, and the like. reinforcing plates 10 and 11 to resist against a force T _2.
[0031]
In the above, the PC box girder bridge by the cast-in-place method has been described. However, the present invention is not limited to this. Can be applied. Also, not only the combined method of the inner cable and the outer cable, but also the all-outer cable method, and also the large eccentric outer cable method (extra-dosed bridge) where the outer cable is eccentric to the outside of the range of the girder height. Can do. Moreover, the deflection | deviation part 3 may be not only a rib format but a concrete partition format or a projection format.
[0032]
【The invention's effect】
(1) In an external cable type bridge with a deflection part, the outer cable deflection pipe is attached to a reinforcing plate, and this reinforcement plate is embedded in the concrete part of the deflection part and the main girder. The tube can be attached to the reinforcing plate with high accuracy in advance at a factory or the like, and the deflection tube can be installed with high accuracy and accuracy when the deflection unit is constructed.
[0033]
(2) By integrating the deflection pipe and the reinforcing plate and adding a stopper to the reinforcing plate, it is possible to use the reinforcing plate as an alternative to the reinforcing bar of the deflecting part, reducing the amount of reinforcing bars placed on the deflecting part. This makes it easy to assemble.
[0034]
(3) Since the amount of reinforcing bars to be arranged is reduced, concrete can be driven easily and reliably, and dense concrete can be constructed.
[0035]
(4) As described above, it is possible to economically construct an external cable type PC bridge having a sound deflection portion reinforced reliably.
[Brief description of the drawings]
1A and 1B show a first embodiment of a deflector structure according to the present invention, in which FIG. 1A is a side view, FIG. 1B is a plan view, and FIG. 1C and FIG.
FIG. 2 is a perspective view showing a deflection pipe and reinforcing plate unit used in FIG. 1;
FIG. 3 is a perspective view showing a deflection pipe and reinforcing plate unit used in FIG. 1;
4A and 4B show a second embodiment of the deflecting portion structure of the present invention, in which FIG. 4A is a side view, FIG. 4B is a plan view, and FIG. 4C and FIG.
FIG. 5 is a perspective view showing a deflection pipe and reinforcing plate unit used in FIG. 2;
6 is a perspective view showing a deflection pipe and reinforcing plate unit used in FIG. 2. FIG.
FIG. 7 is a perspective view showing an external cable type PC bridge.
8A and 8B show a conventional deflector structure, in which FIG. 8A is a side view, FIG. 8B is a plan view, and FIG. 8C and FIG.
[Explanation of symbols]
1 ... Main girder 1a ... Upper floor slab 1b ... Web 1c ... Lower floor slab 2 ... Outer cable (tension material)
3 ...... deflecting portion 3a ... rib 4 ...... fulcrum cross beam 5 ...... deflection tube 6 ...... the cable 10 ...... reinforcing plate 10a ... dowel hole 11 ...... reinforcing plate 12 ...... Sutaddoji Bell

Claims (2)

  An external cable type bridge that prestresses the main girder via a tension member fixing part and a deflecting part, and is embedded in the deflecting part. The deflecting tube through which the tension material is inserted is attached to a reinforcing plate that intersects the axial direction of the deflecting tube, and a plurality of reinforcing plates are arranged at intervals in the bridge axial direction, and the deflecting tubes of each reinforcing plate penetrate A bridge using an outer cable, characterized in that a main body portion to be attached is embedded in a deflection portion, and an end portion of each reinforcing plate is embedded in a concrete member of a main girder. The bridge according to claim 1 , wherein the reinforcing plate is provided with a stopper for integrating the reinforcing plate with the deflection portion and the concrete of the main girder .

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