JP4416337B2 - Construction method of the replacement composite floor slab girder bridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a construction method of a replacement composite slab steel girder bridge in which an existing reinforced concrete floor slab is replaced and a bridge is constructed by a reinforced concrete floor slab that is strength-combined (bonded and reinforced) with a steel plate.
[0002]
[Prior art]
In a steel girder bridge constructed by supporting a slab with a steel main girder extending in the direction of the bridge axis, reinforced concrete slabs (hereinafter referred to as RC slabs) formed of reinforced concrete are often used for the slabs. ing.
[0003]
RC floor slabs are constructed by placing a formwork on the main girder and placing concrete inside the steel bar. The steel main girder is a gibber planted on the upper surface of the steel main girder. It is buried in the plate and coupled so that shear force can be transmitted.
[0004]
Recently, in existing steel girder bridges using such RC slabs, the RC slabs that have been damaged due to the increase in heavy vehicles, lack of floor slab thickness, etc. are positioned along the back side. A so-called under deck panel method is known in which a steel plate is joined to a main girder for reinforcement.
[0005]
That is, as shown in FIG. 9 which is a cross-sectional perspective view of a bridge reinforced by the example, the width direction orthogonal to the bridge axis can cover the lower surface of the RC floor slab 92 excluding the haunch between the main girders 91 and the bridge axis. The under deck panel 93 having a predetermined length is fastened to the belly plate of the main girder 91 via the bracket 94 with a filler such as resin mortar interposed between the upper surface and the lower surface of the RC floor slab 92. It is worn and configured.
[0006]
In the under deck panel 93, a plurality of longitudinal ribs 93B in the bridge axis direction are arranged at predetermined intervals in the direction orthogonal to the bridge axis on the lower surface side of the supporting steel plate 93A having a predetermined plate thickness, and the under deck panel 93 is laterally orthogonal to the bridge axis. The ribs 93C are firmly formed at predetermined intervals in the bridge axis direction, and the side ends of the lateral ribs 93C are fastened and fixed to the bracket 94 with high-strength bolts.
[0007]
By applying such a reinforcing structure by the under deck panel method, it is possible to increase the bending strength and the shear strength and to suppress the progress of damage to the floor slab.
[0008]
[Problems to be solved by the invention]
However, even the RC slab steel girder bridge reinforced by the under deck panel construction method as described above will eventually need to be replaced with a new slab.
[0009]
For RC floor slab replacement, it is common to cut and remove the existing RC floor slab and reconstruct the same RC floor slab on the main girder as before. In addition, it takes a long time to lay concrete with steel bars inside, and for this reason, the construction cost is high and the existing floor assembly is used. There was a problem that it could not be achieved. There is also a problem that the traffic regulation period that must be performed during the work is long.
[0010]
The present invention has been made in view of the above-mentioned problem, and the floor deck of the RC floor slab steel girder bridge to which the reinforcement structure by the under deck panel method is applied is combined with the under deck panel ( strengthened by combining ). Then, it aims at provision of the construction method of the replacement synthetic floor slab steel girder bridge which can be replaced to RC floor slab with high durability at low cost for a short time.
[0011]
[Means for Solving the Problems]
The construction method of the replacement composite floor slab steel girder bridge of the present invention that achieves the above object is that the supporting plate member positioned along the lower surface of the existing reinforced concrete floor slab is coupled to the steel girder, and the existing reinforced concrete floor slab is used. Replacing composite floor slab that removes existing reinforced concrete floor slab of existing reinforced concrete floor slab steel girder bridge having reinforcing structure supported by said steel girder via said support plate member and replaces it with new concrete. In the construction method of steel girder bridge,
The existing reinforced concrete floor slab is removed leaving the support plate member, and a coupling means is disposed on the remaining upper surface of the support plate member, and then concrete is placed on the remaining support plate member. A reinforced concrete slab reinforced by combining the concrete with the support plate member via the coupling means is formed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0014]
FIG. 1 is a transverse cross-sectional view of an RC floor slab steel girder bridge which is an example of the structure of a replaceable composite floor slab girder bridge according to the present invention, and FIG. 2 is a vertical cross-sectional view corresponding to the AA cross section thereof. . Note that FIG. 1 shows a substantially left half, and the right side edge in the figure is omitted. 3 shows the existing reinforced concrete floor slab steel girder bridge before the floor slab replacement in this configuration example, (A) is a cross section before reinforcement by the under deck panel method, and (B) is an under deck. It is a cross section after reinforcement construction by a panel construction method.
[0015]
The illustrated RC floor slab steel girder bridge 10 is configured to support a floor slab 12 made of reinforced concrete by a main girder 11 extending in a bridge axis direction provided at predetermined intervals in a direction orthogonal to the bridge axis. 11 is supported and installed on a pier (not shown) via a support.
[0016]
The main girder 11 is a steel girder having an I-shaped cross section provided with flanges (upper flange 11U, lower flange 11L) having predetermined widths at the upper and lower end edges of the abdominal plate 11W having a predetermined height, and the lower flange 11L is a bridge pier. It is designed to be supported via a bearing.
[0017]
The floor slab 12 is formed of reinforced concrete having a reinforcing bar 12A disposed therein, and is coupled to the main girder 11 so as to be able to transmit a shearing force by a dowel 11A planted on the upper surface of the upper flange 11U of the main girder 11. . A pavement 14 having a predetermined thickness is constructed on the upper side by asphalt or the like.
[0018]
In addition, an under deck panel 20 as a support plate member is installed between the main girders 11 and a reinforcing structure is provided by an under deck panel construction method. A coupling means is provided on the upper surface of the support steel plate 21 of the under deck panel 20. The under deck panel 20 is combined and integrated with the floor slab 12 so that strength can be combined (bonded and reinforced) .
[0019]
The under deck panel 20 has a plurality of longitudinal ribs 22 in the bridge axis direction arranged at predetermined intervals in the direction orthogonal to the bridge axis on the lower surface side of the support steel plate 21 having a predetermined plate thickness, and the transverse direction orthogonal to the bridge axis. The ribs 23 are disposed firmly at predetermined intervals in the bridge axis direction and are firmly formed, and the ends of the lateral ribs 23 are firmly fastened to the abdomen 11W of the main girder 11 via the brackets 14 with high-strength bolts. It will be installed. In the figure, reference numeral 15 denotes a tilting structure installed between the main girders 11 and arranged at a predetermined interval in the bridge axis direction. The length of the under deck panel 20 in the bridge axis direction is set so as not to interfere with the anti-tilt structure 15.
[0020]
The connecting structural member 30 is planted on the upper surface of the support steel plate 21 of the under deck panel 20 as shown in FIG. 4 (A) which is a partial plan view of the floor slab 12 excluding concrete and (B) which is a side view thereof. It is composed of a provided gibber 31 with a predetermined length and a reinforcing joint steel 32 fastened to the diver 31 with a nut 33.
[0021]
The gibber 31 is a shaft having a predetermined length with a screw formed at the tip, and is arranged in a row at a position where the reinforcing joint shaped steel 32 on the upper surface of the supporting steel plate 21 is to be disposed. In addition, the planting position may be planted other than the position where the reinforced bonded section steel 32 is disposed as required for the bonding strength.
[0022]
The reinforcing joint section 32 is a Z-shaped section section having flanges 32U and 32L having predetermined widths extending in opposite directions on the upper and lower edges of the vertical belly plate 32W, and the lower flange 32L thereof. Is fastened and fixed to the upper surface of the supporting steel plate 21 by a nut 33 screwed into the tip screw portion of the gibber 31 penetrating through. The length of the floor slab 12 extends over the substantially entire width direction of the floor slab 12 and reaches a side end portion that protrudes laterally from the support portion of the main girder 11, thereby providing a separate under deck positioned across the main girder 11. The panel 20 is connected via the reinforcing bonded section 32.
[0023]
When the connecting structural member 30 having the above-described structure is immersed in the concrete of the floor slab 12, the under deck panel 20 fixed to the main girder 11 and the floor slab 12 are combined and integrated so that strength can be combined (bonded and reinforced). And can be made into a highly rigid and highly durable synthetic floor slab. Reinforced joint shaped steel 32 is located inside the floor slab 12 and reinforces it in the direction perpendicular to the bridge axis, which is the longitudinal direction thereof. Since the side edge portion is reached, the rigidity of the side portion protruding from the main girder 11 to the side can be improved.
[0024]
Next, a construction method for replacing the floor slab 12 'of the existing RC floor slab girder bridge 10' shown in FIG.
[0025]
First, the floor slab 12 'of the RC floor slab steel girder bridge 10' reinforced by the under deck panel method shown in FIG. 3 (B) is removed by appropriately subdividing it, and a partial sectional view is shown in FIG. The under deck panel 20 and the main girder 11 remain.
[0026]
Next, as shown in FIG. 6, the gibbers 31, 11 </ b> A are implanted on the upper surface of the support steel plate 21 of the under deck panel 20 and the upper surface of the upper flange 11 </ b> U of the main girder 11. As shown in FIGS. 7A and 7B in enlarged sectional views, a reinforced bonded structural steel 32 is fastened and fixed with a nut 33 to form a bonded structural member 30, and an upper flange of the reinforced bonded structural steel 32 is further formed. After reinforcing bars 12A are arranged on the upper side of 32U to the state shown in FIG. 8, concrete is cast to form the floor slab 12, thereby completing the construction as shown in FIG.
[0027]
According to such a construction method, since the under deck panel 20 functions as a formwork on the lower surface side when placing concrete, it is not necessary to install the formwork, so that the construction time can be shortened. Since the panel 20 and the floor slab 12 are combined with strength (combined and reinforced), the rigidity is significantly improved as compared with before the replacement. For this reason, the floor slab 12 can be configured to be thin and light (with a small dead load) if the load is the same, and the load can be increased if the thickness is the same.
[0028]
In addition, the shape of the reinforced bonded section steel as a coupling means and its fixing structure are not limited to the above configuration example, and can be changed as appropriate, and the reinforced coupled section steel is not necessarily used, and the above configuration example In FIG. 8, a large number of gibber having a large diameter portion at the tip end similar to the gibber 11A planted on the upper flange 11U of the main girder 11 may be planted.
[0029]
【The invention's effect】
As described above, according to the construction method of the replaceable composite slab steel girder bridge according to the present invention, the support plate member positioned along the lower surface of the existing reinforced concrete floor slab is coupled to the steel girder, and the existing girder is installed. The existing reinforced concrete floor slab steel girder bridge having a reinforcing structure for supporting the reinforced concrete floor slab by the steel girder through the support plate member is removed, and the existing reinforced concrete floor slab is removed and replaced with new concrete. In the construction method of the replacement composite slab steel girder bridge, the existing reinforced concrete floor slab is removed leaving the support plate member, and after the coupling means is disposed on the upper surface of the remaining support plate member, the remaining is left Concrete is placed on the support plate member, and the concrete is combined with the support plate member via the coupling means to form a reinforced concrete slab. Then, after removing the reinforced concrete slab and arranging the coupling means on the upper surface of the support plate member, the support plate member is reinforced concrete floor by placing concrete and forming the reinforced concrete floor slab combined with the support plate member. Since it functions as a formwork on the lower surface side when placing concrete during plate construction, it is not necessary to install a formwork, enabling rational construction and shortening the construction period. In addition, since the support plate member is strength-combined (bonded and reinforced) with the reinforced concrete floor slab after construction, the rigidity is greatly improved compared to before replacement. For this reason, the reinforced concrete floor slab can be configured to be thin and light if the load is the same, and the load can be increased if the thickness is the same.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a reinforced concrete floor slab steel girder bridge which is an example of the configuration of a replaceable composite floor slab steel girder according to the present invention.
FIG. 2 is a longitudinal sectional view corresponding to the AA sectional view.
3A is a cross section of an RC floor slab steel girder bridge before reinforcement by the under deck panel method, and FIG. 3B is a cross section after reinforcement work by the under deck panel method.
4A is a partial plan view of a floor slab with concrete removed, and FIG. 4B is a side view thereof.
FIG. 5 is a cross-sectional view illustrating a construction process.
FIG. 6 is a cross-sectional view illustrating a construction process.
FIG. 7 is a partial cross-sectional view illustrating an installation process of a coupling structural member.
FIG. 8 is a cross-sectional view illustrating a construction process.
FIG. 9 is a cross-sectional perspective view of a bridge reinforced by an under deck panel method as a conventional example.
[Explanation of symbols]
10 RC floor slab steel girder bridge (Reinforced concrete floor slab girder bridge)
11 Main girder 12 Floor slab (Reinforced concrete floor slab)
20 Under deck panel (support plate member)
30 Joining structural member (joining means)

Claims (1)

Support plate member positioned along the lower surface of the existing concrete deck is bonded to the steel girder, existing reinforced concrete floor with a reinforcing structure for supporting a reinforced concrete floor slab of the existing by the steel girder through said support plate member In the construction method of the replacement composite floor slab girder bridge in which the existing reinforced concrete floor slab of the plate steel girder bridge is removed and new concrete is placed and replaced,
The reinforced concrete slab of the existing removed leaving the support plate member, after providing the coupling means on the upper surface of the remaining said support plate member, and Da設the concrete remaining the support plate member on construction method threshing replacement synthesis slab steel girder bridges, characterized in that as the concrete to form the reinforced concrete floor slab reinforced in conjunction with the support plate member through said coupling means.

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