JP3853346B2 - Structure of floor slab bridge - Google Patents

Description

  The present invention relates to a structure of a floor slab bridge in a river or land bridge, and more particularly to a structure of a floor slab bridge using columnar H-shaped steel as a main girder.

  In FIGS. 1 and 2 of Japanese Patent Laid-Open No. 9-221717, a steel sheet pile 11 is used as a bottom plate, and T-shaped steel or H-shaped steel (main girder member 13) is welded to the steel sheet pile 11 at intervals. The steel sheet piles 11 are joined together by the claw portions 12 provided in parallel on the left and right end faces of the steel sheet piles 11, and the concrete inlets formed between the upper flanges of each T-shaped steel or H-shaped steel. Concrete is cast in a space between the upper flange of the T-shaped steel or H-shaped steel and the steel sheet pile 11 to form a lower concrete layer, and concrete is cast on the upper flange to It shows a floor slab bridge with an upper concrete layer connected through a concrete inlet.

  Similarly, FIG. 5 shows a floor slab bridge in which a plurality of T-shaped steels or H-shaped steels are juxtaposed to a bottom plate 3 made of a single steel plate and concrete is cast.

  In these floor slab bridges, the side plate 16 is filled on the outer side surface of the side concrete layer placed on the outer side surface of the T-shaped steel or H-shaped steel at the left and right end, and the floor shown in FIGS. In the slab bridge, a PC steel material 18 penetrating from the outer side surface of the side plate 16 through a parallel plate T-shaped steel or H-shaped steel plate, a lower concrete layer, and a block called a cross beam 19 is penetrated. Both ends of the side plate 16 are tightened on the outer side surface of the side plate 16, and the play of the joint portion of the claw portion 12 is maximized to prestress the concrete layer. Inevitably, the PC steel material 18 used as the prestressing means has both ends tightened portions exposed on the outer surface of the side plate 16.

  Thus, in the above conventional structure, the steel sheet pile 11 is formed with the steel sheet pile 11 as described above, and the steel sheet pile 11 is arranged on the bottom plate with T-shaped steel or H-shaped steel arranged at intervals. The play of the joint part of the claw part 12 is maximized, and after the placed concrete is hardened, the PC steel material 18 is fastened on the outer surface of the side plate 16 to prestress the concrete layer. The PC steel material 18 has play in a block called a cross beam 19 and is fastened so as to be fastened to give the prestress. Therefore, the PC steel material 18 is not bonded to concrete at all and does not function as a concrete reinforcing bar.

  Therefore, when a vertical load (live load) due to vehicle traffic is applied to the floor slab bridge, there is a problem that shearing force acts on the concrete layer and induces cracking of the concrete layer.

  Further, since the PC steel material 18 is tightened on the outer side surfaces of the both side plates 16, all loads are applied to the tightening portion of the side plates 16, and there is a problem that the side plates 16 are tilted or distorted.

  In addition, the tightening portion is exposed from the side plate 16, that is, exposed from the concrete layer, and the tightening portion is corroded by wind and rain and has a problem of impairing the function and a problem of impairing the appearance of the floor slab bridge. .

  In addition, the bottom plate 3 and the steel sheet pile 11 each have a very complicated work that requires fillet welding over the entire length of the T-shaped steel or H-shaped steel at regular intervals. Bring.

  In the present invention, a plurality of columnar H-shaped steels, that is, commercially available H-shaped steels of JIS specifications, are juxtaposed while bridging a plurality of bridges between the piers with the lower flanges, and the plates of the lower flanges are arranged in parallel. The bottom plates are formed by butting the lower flanges with the thick side end faces butting each other.

  Then, a concrete inlet is formed between the upper flanges by cutting the upper flanges to be shorter than the lower flanges, and the concrete inlets are defined between the upper flanges, the lower flanges, and the belly plates. Concrete is cast in the formed space to form a lower concrete layer, and concrete is cast on each of the upper flanges to form an upper concrete layer to be coupled to the lower concrete layer through the concrete inlet.

  Further, a reinforcing bar is laid horizontally on the upper flange, and a suspended reinforcing bar suspended from the horizontal reinforcing bar through the concrete inlet is placed in the space, and the horizontal reinforcing bar is embedded in the upper concrete layer. At the same time, the floor slab bridge is constructed with suspended reinforcing bars embedded in the lower concrete layer.

  The above-mentioned horizontal reinforcing bars and the reinforcing bars suspended from the horizontal reinforcing bars appropriately reinforce the bonding strength of the upper concrete layer and the lower concrete layer, especially the lower concrete layer divided by the abdominal plate, Strength can be imparted.

  Therefore, the shear strength of concrete against live load is increased and cracks are effectively prevented.

  In general, a slab bridge can be constructed at low cost and in a short construction period by simply laying the upper flange of the columnar H-section steel of JIS specifications in width and simply placing the lower flange in abutment between the bridge piers in parallel and placing concrete. .

  Further, a plurality of columnar H-shaped steels are juxtaposed while bridging between the piers with the lower flange, and the juxtaposed end surfaces of the thicknesses of the lower flanges are brought into contact with each other, and then arranged in parallel. An abdominal threading rod is inserted into the abdominal plate of the columnar H-shaped steel, and a large number of the abdominal threading rods are arranged at narrow intervals in the bridge length direction. A stopper such as a nut that abuts the outer surface of the shape steel belly plate is provided.

  Each upper flange is made shorter than each lower flange to form a concrete inlet between the upper flanges. Within the space defined by the upper flange, each lower flange, and each belly plate from the concrete inlet. Concrete is cast on the upper flange to form a lower concrete layer, and concrete is cast on each upper flange to form an upper concrete layer that is connected to the lower concrete layer through the concrete inlet. A side in which the rod is embedded in the lower concrete layer cast in the space to be a concrete reinforcing bar, and both ends and stoppers of the belly bar are placed on the outer side surface of the columnar H-shaped steel at the left and right end. A floor slab bridge is formed by embedding it in the concrete layer.

  The above-mentioned abdominal threading rod uses a headed rod having a head (stopper) at one end, and a nut (stopper) is screwed to the other end to fasten it to the outer side surface of the columnar H-shaped steel at the left and right end. Alternatively, the above-mentioned belly bar is screwed onto both ends of the rod and fastened to the outer side surface of the columnar H-shaped steel plate at the left and right end.

  This tightening force is a fastening force that does not give a butting force to the butting portion of the lower flange of each columnar H-shaped steel. That is, the lower flanges of the columnar H-shaped steels are only in free contact with each other (there is no problem even if there is a slight gap).

  The above-mentioned belly bar is embedded in the lower concrete layer and functions as a concrete reinforcement, enhances the shear strength against the active load applied to the concrete layer, and effectively prevents cracks in the concrete. In addition, by embedding both ends of the stopper and the belly bar in the side concrete layer, corrosion due to wind and rain is prevented, and the appearance is not impaired.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, a plurality of columnar H-section steels 1 in which a lower flange 2 and an upper flange 4 are joined by a belly plate 3, that is, a commercially available H-section steel 1 of JIS specifications are used. 3, as shown in FIG. 6, each columnar H-section steel 1 is juxtaposed with a plurality of bridges between the bridge piers 5 with the lower flange 2, and the juxtaposed end faces of the lower flanges 2 are arranged side by side. 2a is brought into butt contact with each other.

  As shown in FIGS. 3 and 6, both ends of the columnar H-section steel 1 are bridged and supported on the bearing surfaces of the bridge piers 5 and 5 via rubber bearings 6 and the like, and both ends of the lower flange 2 are bridge piers by anchor bolts 7. Attach to 5.

  As shown in FIG. 4, the upper flanges 4 are made shorter than the lower flanges 2, and the concrete inlets 8 shown in FIG. 1 are formed between the upper flanges 4.

  The columnar H-section steel 1 uses a steel column of a JIS specification (JISG3101 steel, JISG3106 steel, JISG3114 steel, etc.) composed of a lower flange 2, an upper flange 4 and a belly plate 3, and as shown in FIG. Both ends of the upper flange 4 of the steel 1 are cut out at equal widths so as to be narrower than the lower flange 2, and this is prepared in advance and carried into the site.

  Alternatively, as shown in FIG. 5, one half of the upper flange 4 of the columnar H-section steel 1 is cut off from the joint with the abdomen plate 3, and the lower flange 2 is formed while arranging a large number of the columnar H-section steels 1 in parallel. The concrete inflow port 8 is formed in a butted state.

  As shown in FIG. 1, concrete 9 is placed in a space S defined between each upper flange 4, each lower flange 2, and each belly plate 3 from the concrete inlet 8 to form a lower concrete layer 10. To do.

  Further, concrete 9 is placed on each upper flange 4 to form an upper concrete layer 11 that is connected to the lower concrete layer 10 through the concrete inlet 8.

  As the columnar H-section steel 1, the outer surface is plated with zinc or the like, or is coated with a paint.

  In the embodiment shown in FIG. 1, the upper flange 4 of the columnar H-section steel 1 of JIS specifications is cut into widths, and the bridge piers 5 are simply bridged in parallel, and the concrete slabs 9 are used to make the floor slab bridge inexpensive. It can be built in a short construction period.

  Further, as shown in FIG. 1, a formwork side plate 14 is assembled on the outer side of each columnar H-shaped steel 1 'at the left and right ends (the left and right ends in the bridge width direction) in the parallel columnar H-shaped ropes 1 to form the same columnar shape. Concrete 9 is cast on the outer side of the H-shaped rope 1 'to form a side concrete layer 10'.

  In other words, concrete 9 is placed in the space S ″ defined by the lower flange 2, the abdominal plate 3, the upper flange 4, and the mold side plate 14 of each columnar H-section steel 1 ′ at the left and right ends, and the side concrete. Layer 10 'is formed.

  The formwork side plate 14 is removed after the concrete is hardened. Actually, the lower concrete layer 10, the upper concrete layer 11, and the side concrete layer 10 ′ are not separately cast concrete, but are continuously cast, and the side concrete layer 10 is placed on both ends of the upper concrete layer 11. Strike ′ together. A balustrade 21 is integrally raised at the upper end of the side concrete layer 10 '.

  Further, a reinforcing bar is horizontally provided on the upper flange 4, and a suspended reinforcing bar 13 is assembled to the horizontal reinforcing bar 12, and the suspended reinforcing bar 13 is suspended in the space S through the concrete inlet 8. . Then, the horizontal reinforcing bars 12 are embedded in the upper concrete layer 11 and the suspended reinforcing bars 13 are embedded in the lower concrete layer 10 to construct a floor slab bridge.

  A suspended reinforcing bar 13 is suspended in the space S ″ on the left and right outer sides of the columnar H-shaped rope column 1 ′ at the left and right ends, and the suspended reinforcing bar 13 is embedded in the side concrete layer 10 ′.

  As shown in FIG. 1, the suspended reinforcing bar 13 is U-shaped in the bridge width direction or U-shaped in the bridge length direction, and both upper ends are suspended from the horizontal reinforcing bar 12.

  The horizontal reinforcing bars 12 are supported on the upper surface of each upper flange 4 and receive the horizontal reinforcing bars 12 and the suspended reinforcing bars 13. Of course, a large number of the reinforcing bars 12 and 13 are arranged in the bridge length direction of the H-section steel 1 through narrow intervals.

  Further, the vertical reinforcing bars 12 'extending in the bridge length direction are combined with the horizontal reinforcing bars 12 and the suspended reinforcing bars 13, and the entire vertical reinforcing bars 12' are assembled in a bowl shape. It is supported by a horizontal reinforcing bar 12 that is supported horizontally.

  The horizontal reinforcing bars 12 and the suspended reinforcing bars 13 suspended from the horizontal reinforcing bars 12 appropriately reinforce the bonding strength of the upper concrete layer 11 and the lower concrete layer 10, particularly the lower concrete layer 10 separated by the stomach plate 3. Strength is given to the entire floor slab bridge.

  Therefore, the shear strength of the concrete 9 with respect to the live load is increased, and cracks in the upper and lower concrete layers 11 and 10 are effectively prevented.

  As another example, as shown in FIG. 1, a through hole 3a is provided in the abdominal plate 3 of the full columnar H-section steel 1 which is arranged side by side and directly contacts the lower flange 2, and the abdominal threading rod is provided in the through hole 3a. 3 and 6, as shown in FIGS. 3 and 6, a large number of the abdominal threading rods 16 are arranged at narrow intervals in the bridge length direction. A stopper 17 such as a nut that abuts on the outer surface of the belly plate 3 of the columnar H-section steel 1 ′ is provided.

  As shown in FIG. 3, a large number of the abdominal threading rods 16 are arranged in a single row at narrow intervals in the bridge length direction. Alternatively, as shown in FIG. 6, the rows of the abdominal threading bars 16 are arranged in a double row in the upper and lower stages.

  Each of the abdominal threading rods 16 is buried in the lower concrete layer 10 placed through the concrete inflow port 8 to form a concrete reinforcing bar.

  On the other hand, both ends of the abdominal threading rod 16 and the stopper 17 are embedded in the side concrete layer 10 'which is placed on the outer side surface of the columnar H-section steel 1' at the left and right end.

  The abdominal bar 16 is a headed bar having a head (stopper 17) at one end, and a nut (stopper 17) is screwed to the other end to externally face the abdominal plate 3 of the columnar H-shaped steel 1 'at the left and right ends. Tighten to. Alternatively, the abdominal threading rod 16 is fastened to the outer surface of the abdominal plate 3 of the columnar H-section steel 1 'at the left and right ends by screwing nuts to both ends.

  This fastening force is a fastening force that does not give a butt force to the butt portion of the lower flange 2 of each columnar H-section steel 1. That is, the lower flanges 2 of the columnar H-sections 1 are only in free contact with each other (there is no problem even if there is a slight gap).

  The belly bar 16 is embedded in the lower concrete layer 10 and functions as a concrete reinforcing bar as described above. That is, as shown in FIG. 1, when a vertical load A due to vehicle traffic or the like is applied to the floor slab bridge, a parallel joint portion between the columnar H-section steel 1 under the load and the adjacent columnar H-section steel 1; Although the shear force B acts on the concrete layers 10 and 11 corresponding to the joints, the belly bar 16 effectively prevents the problem of inducing cracks (shearing) in the concrete layers 10 and 11 due to the vertical load A. To do.

  Similarly, the horizontal reinforcing bars 12 and the suspended reinforcing bars 13 are combined with the concrete 9 (concrete layers 10 and 11) to improve the shear prevention effect. The combined use of the reinforcing bars 12 and 13 and the abdominal threading rod 16 is not hindered.

  Further, both ends of the stopper and the belly bar are embedded in the side concrete layer, so that corrosion due to wind and rain is prevented, and the belly bar 16 functions soundly over time without damaging the appearance.

  As another example, as shown in FIG. 6, a lightweight material 20 such as foamed resin or foamed concrete is disposed in each space S defined between the upper flange 4, the abdomen 3, and the lower flange 2. And embedded in the lower concrete layer 10.

  The lightweight material 20, preferably a rectangular block-shaped lightweight material 20, is interposed between the abdominal plates 3 and is brought into close contact with the abdominal plates 3.

  As shown in FIG. 6, a large number of the lightweight materials 20 are arranged in the bridge length direction so as not to interfere with the abdominal threading rods 16, and the thickening of the lower concrete layer 10, that is, the large columnar H-section steel 1 having a high height is provided. While being used, the lightweight material 20 is embedded to reduce the weight (reduce the dead load) while increasing the thickness of the entire floor slab.

  The lightweight material 20 is embedded in the center of the lower concrete layer 10, and the belly bar 16 is separated by the lightweight material 20 from the lower concrete layer portion on the upper flange 4 side and the lower concrete layer portion on the lower flange 2 side. Intrude each inside.

  The suspension rebar 13 and the belly bar 16 are provided in the space above the lightweight material 20, and the concrete 9 is placed and embedded in the lower concrete layer portion on the upper flange 4 side.

  In addition, a large number of reinforcing bars formed in a ring shape or the like in the space below the lightweight material 20 are arranged in the bridge width direction and the bridge length direction, and the vertical reinforcing bars are combined with the ring reinforcing bar to form a hook shape. It is embedded in the concrete layer filled in the space, that is, the lower concrete layer portion on the lower flange 2 side.

The cross-sectional view which shows the structure of the floor slab bridge formed by columnar H-section steel and concrete placement. The top view shown with the bridge | crosslinking juxtaposition state of the columnar H-section steel before concrete placement. The same side view. The cross-sectional view which shows the example which forms a concrete inflow port in the said columnar H shape rope. The cross-sectional view which shows the other example which forms a concrete inflow port in the said columnar H shape rope. The side view of the floor slab bridge which shows the example which applied the lightweight material.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1 '... Columnar H-section steel, 2 ... Lower flange, 2a ... Plate thickness side end surface of lower flange, 3 ... Abdominal plate, 3a ... Through hole of abdominal plate, 4 ... Upper flange, 5 ... Bridge pier, 6 ... Rubber Support, 7 ... Anchor bolt, 8 ... Concrete inlet, 9 ... Concrete, 10 ... Lower concrete layer, 10 '... Side concrete layer, 11 ... Upper concrete layer, 12 ... Horizontal reinforcing bar, 12' ... Vertical reinforcing bar, DESCRIPTION OF SYMBOLS 13 ... Reinforcing bar, 14 ... Formwork side plate, 16 ... Stomach rod, 17 ... Stopper, 20 ... Lightweight material, 21 ... Parapet, A ... Vertical load, B ... Shear force, S, S "... Space

Claims (2)

A plurality of columnar H-shaped steel juxtaposed with bridges between piers drives out the bottom flange, to one another butt condition the thickness end surface of each lower flange by said parallel set, each of the respective columnar H-shaped steel The upper flange is made shorter than each lower flange to form a concrete inlet between the upper flanges, and the concrete is put into the space defined between the upper flange, the lower flange, and the belly plate from the concrete inlet. Casting to form a lower concrete layer, placing concrete on each upper flange to form an upper concrete layer to be coupled to the lower concrete layer through the concrete inlet, and further on each upper flange A horizontal reinforcing bar that is horizontally installed, and a suspended reinforcing bar that is suspended from the horizontal reinforcing bar in the space through the concrete inflow port. With burying the lateral 設鉄 muscle cleat layer, the structure of the floor slab bridge, characterized in that embedded the suspending 設鉄 muscle in the lower concrete layer. An abdominal threading rod is inserted through the columnar H-shaped steel bellows arranged side by side, and a large number of the abdominal threading bars are arranged at narrow intervals in the bridge length direction. A stopper such as a nut that abuts the outer surface of the columnar H-shaped steel plate at the end is provided, and the respective through-rods are embedded in a lower concrete layer cast in the space. Structure of floor slab bridge as described.

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