JPH09256320A - Intermittent synthetic slab bridge - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: A crack generated in a concrete slab of an intermittent synthetic slab bridge over a plurality of spans in which a steel girder and concrete intermittently form a synthetic slab and a non-synthetic slab in the longitudinal direction. Prevent. SOLUTION: An upper flange 9a of a steel girder at the upper part of the intermediate bearings 4 and 5 of a multi-span intermittent synthetic slab bridge 10 is formed wider than other portions, and upper and lower surfaces of the upper flange 9a of the wide portion. A plate-like rubber 13 is attached to the above to form a non-synthetic floor slab, and a projection 9c for integrating with the concrete 7 is attached to the upper flange 9e other than the wide width to form a synthetic floor slab bridge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic slab bridge in which one part in the longitudinal direction is a synthetic floor slab and the other part is a non-synthetic floor slab, and the bridge is continuous in multiple spans in the longitudinal direction. Regarding the slab bridge. The multispan here means at least two spans or more.

[0002]

2. Description of the Related Art Viaducts are often used in urban areas such as expressways in order to effectively use land and alleviate traffic congestion. In a simple support composite slab bridge that is erected for each span, expansion and contraction joints are installed at each end to accommodate expansion and contraction due to temperature changes in the composite slab bridge and rotation of that end, causing water leakage. , Corrosion of girder ends is required, and repair and maintenance are required. Furthermore, when a vehicle passes through a seam of a simply supported composite deck slab at high speed, vibration and noise are generated, which causes a deterioration of the environment. There is.

For this reason, continuous slab bridges using continuous girders spanning multiple diameters and having a small number of joints are often used for viaducts on expressways. FIG. 4 illustrates a continuous slab bridge having continuous girders with three spans. In this bridge, continuous steel girders 9 are erected on four bridge piers 2, and continuous asphalt pavement 11 is constructed on a composite floor slab that combines concrete 1 and steel girders 9. It has decreased significantly.

Incidentally, Japanese Patent Publication No. 3-48285 or Japanese Utility Model Publication No. 7-39927 discloses a hollow type synthetic slab bridge. This hollow type composite slab bridge has excellent properties because it has a lower girder height, is lighter in weight, can be applied with a larger span distance, and has a greater property than a solid synthetic slab bridge.

[0005]

However, the continuous slab bridge has the following problems. For example, FIG. 3 shows a bending moment diagram when a uniformly distributed load is applied to the continuous beam having three diameters shown in FIG. The continuous beam 21 having three spans is supported by one fixed bearing 4 and three movable bearings 5. When a uniform load 20 simulating an automatic vehicle load is applied to the continuous beam 21, a negative bending moment that a tensile force acts on the upper surface of the continuous beam 21 in the vicinity of the bearings 4 and 5 in the intermediate portion excluding both ends thereof is applied. Occurs. The actual force acting on the continuous composite slab bridge is different from the evenly distributed load 20, but
As shown in FIG. 3, a negative bending moment may be generated due to a tensile force acting on the continuous composite deck slab over the bearings 4 and 5 in the intermediate portion excluding both ends thereof due to an automatic vehicle load or the like. When this negative bending moment is generated, the concrete is weak in tensile force, so there is a problem that cracks occur in the slab concrete of the continuous composite slab bridge.

In the present invention, in view of the above circumstances, the floor slab concrete and the steel girder are continuous in the longitudinal direction,
The purpose of the present invention is to provide an intermittent synthetic slab bridge that prevents cracks from occurring in the slab concrete by making the upper flange of the steel girder and the slab concrete non-synthetic in the section where a negative bending moment occurs. .

[0007]

[Summary of the Invention] An intermittent composite floor slab bridge is, for example, a composite floor in which concrete and steel girder placed above a steel girder are integrated in a positive bending moment section generated by an automatic vehicle load. In the negative bending moment section of the slab, a non-synthetic floor slab is formed without integrating the concrete and the steel girder placed on the top of the steel girder, and a large number of slabs are spread over multiple diameters. It is a continuous bridge supported by bearings and continuous in the longitudinal direction.

The present invention develops and provides a rational structure for such an intermittent synthetic slab bridge. That is, the first invention of the present invention is a multi-span intermittent synthetic slab bridge in which a steel girder and concrete form a non-synthetic slab on the intermediate bearing and a synthetic slab on the other part, The upper flange of the steel girder above the intermediate bearing is formed wider than the upper flanges of other parts, and plate-shaped edging material is attached to the upper and lower surfaces of this wide upper flange. An intermittent synthetic slab bridge characterized by being equipped with a material to prevent slippage with concrete.

A second aspect of the present invention is a multi-span intermittent synthetic slab bridge in which a steel girder and concrete form a non-synthetic slab on an intermediate bearing and a synthetic slab on other portions. , The upper flange of the steel girder above the intermediate bearing is formed thicker than the upper flanges of other parts, and the upper surface and side surfaces of this thick upper flange are covered with a cap-shaped edging material,
This is an intermittent synthetic slab bridge characterized in that top flanges other than thick-walled parts are equipped with a material to prevent slippage with concrete.

In the present invention, the edging material is interposed between the floor slab concrete and the steel girder flange surface, and is easily deformed by shearing force or bearing force acting between the concrete and the steel girder flange, or A material that causes slippage and does not transfer shearing force or bearing force between concrete and steel girders.
Concrete and steel girders can be put together on the composite floor by pasting the plate-shaped edging material on the upper and lower surfaces of the wide upper flange of the steel girder or by covering the upper and side surfaces of the thick upper flange in a cap shape. Forming the plate is prevented. Further, in the present invention, the anti-slip material is a dowel stud that is welded to the surface of the steel girder or a protrusion on the surface of the steel girder in order to mechanically integrate the steel girder and concrete to form a composite floor slab. Refers to rib protrusions, etc. that are provided. Such a slip prevention material has an appropriate shape by welding or other means depending on the actual situation.
It is provided in the array.

In the present invention described above, when the concrete is expanded concrete containing an expansive material,
It is suitable because there is no risk of cracking. Further, as the edging material, one or more materials selected from the group consisting of hard rubber, soft rubber, synthetic resin, fiber material and asphalt viscoelastic material can be used. As the synthetic resin, vinyl chloride resin, polyolefin, polyester, phenol resin, polyurethane, or fluorine resin can be used, and a foam material may be used. As the fibrous material, inorganic fibers such as carbon and steel, non-woven fabric of organic fibers such as aramid, and FRP can be used. As the edging material using two or more materials, a composite material obtained by bonding, mixing raw materials, or other means can be used. The edging material blocks the connection between the steel girder and the concrete, effectively reduces the tensile stress generated in the concrete, and prevents the occurrence of cracks.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows an intermittent synthetic slab bridge according to an embodiment of the present invention. FIG. 1 (a) is a longitudinal sectional view, FIG. 1 (b) is a plan view of a steel girder, and FIG. 1 (c) is FIG. It is an AA arrow sectional drawing of (a). In FIG. 1, the same components as those of the conventional example shown in FIG. 4 are designated by the same reference numerals.

The three-span intermittent synthetic slab bridge 10 is mounted on four bridge piers 2 and supported by one fixed bearing 4 and three movable bearings 5. The lower flange 9b of the steel girder is supported on the bridge pier 2, and a reinforced concrete cross girder 6 is provided above the bridge pier 2 at right angles to the bridge axis. The intermittent synthetic slab bridge 10 of this embodiment is the same as the above-mentioned Japanese Patent Publication No. 3-48.
Like the technique disclosed in Japanese Patent No. 285 or Japanese Utility Model Publication No. 7-39927, the structure of a hollow type synthetic slab bridge is provided. That is, the steel girder between the bridge piers 2 is hollow, and the hollow polystyrene is filled with styrofoam 3. A concrete floor slab 7 is provided on the expanded polystyrene 3 and the reinforced concrete horizontal girder 6.

In the intermittent synthetic slab bridge of the embodiment shown in FIG.
The upper flange 9a of the steel girder above the intermediate bearings 4 and 5 is formed wide to form an amplifying flange 9d. The upper flanges other than this amplifying flange 9d (hereinafter referred to as ordinary flange portion 9
It is formed wider than the plate width of (e). Further, plate-like rubber 13 is attached to the upper and lower surfaces of the amplification flange 9d. Further, on the surface of the ordinary flange portion 9e, rib projections 9c are projected on the surface of the flange portion 9e in order to integrate the floor slab concrete 7 and the ordinary flange portion 9e. The protrusion 9c may be the stud 15, or the stud 15 may be provided on the lower surface of the flange.

The plate-shaped rubber 13 is an edging material, and is shear-deformed by a shearing force acting on the boundary between the concrete and the steel girder or slips to prevent integration of the steel girder and the concrete. is there. In this example,
As the width of the upper flange is made wider, the stress of concrete near the width change portion of the upper flange may be disturbed. In order to prevent this disorder and to prevent cracking of concrete, wire mesh rebar 1 such as expanded metal
It is advisable to place the floor slab concrete 7 after arranging 2 above the amplification flange 9d as a precautionary bar. In addition, as the floor slab concrete 7, it is preferable to use expansive concrete in which an expansive admixture is added to the mix of ordinary concrete, for the purpose of suppressing the occurrence of cracks due to the drying and shrinking of the concrete.

In this intermittent synthetic floor slab bridge 10, the amplification flange 9d is disconnected from the floor slab concrete by the plate-shaped rubber 13, and a non-synthetic state of so-called flange and floor slab concrete appears to cause concrete generated in the floor slab concrete. Pulling force of the floor plate becomes almost zero, and the slab concrete 7
Prevents cracks from forming. In addition, because of the non-synthesis, the upper flange of this section is subjected to a larger stress than the normal flange portion 9e, but due to the large bending resistance rigidity formed by the amplification flange 9d and the lower flange 9b formed in this section. Therefore, the stress can be suppressed to the extent that it normally occurs in the flange portion 9e section.

Next, another embodiment of the present invention will be described with reference to FIG. In the intermittent composite slab bridge of another embodiment shown in FIG. 2, the upper flange 9a of the steel girder above the intermediate bearings 4 and 5 is formed thick to form a thickened flange portion 9f. It is formed thicker than the plate thickness of the normal flange portion 9e other than the thick flange 9f. Furthermore, the upper surface and the side surface of the thickening flange 9f are covered with a cap-shaped rubber plate 14 (edge cutting material). Further, on the surface of the ordinary flange portion 9e, studs 15 are attached to the surface of the flange portion 9e by welding in order to integrate the slab concrete 7 and the ordinary flange portion 9e. In FIG. 2, this stud 15 is
It is hung on the lower surface of the flange. The stud 15 may be provided not only on the lower surface of the flange but also on the upper surface, and a protrusion such as a rib may be used instead of the stud 15. However, the stud 15 hung vertically on the lower surface of the upper flange does not lift the slab concrete 7 upwardly. On the other hand, since the shear resistance surface of the floor slab concrete 7 is increased and the floor slab concrete resists in cooperation with the upper flange, there is an advantage of improving the sliding fracture resistance of the floor slab concrete 7.

The cap-shaped rubber plate 14 which is an edging material is
Shear deformation or slippage due to the shearing force acting on the boundary between the upper surface and concrete, and
Reversible deformation occurs due to the bearing force acting on the side surface,
Prevents the integration of steel girder and concrete. This rubber plate 1
4 may be a hard rubber plate, a soft rubber plate, a synthetic resin plate, a polystyrene foam plate, an asphalt viscoelastic body, or the like.

Furthermore, in this embodiment, since the thickness of the upper flange is made thicker, the stress of the concrete near the portion where the thickness of the upper flange changes may be disturbed, and cracks may occur in the floor slab concrete. To prevent
It is preferable to place the floor slab concrete 7 after arranging the wire mesh rebar 12 such as expanded metal as a precautionary rebar above the thickened flange portion 9f. Further, as the floor slab concrete 7, it is preferable to use expansive concrete to which an expansive admixture is added, and to suppress the occurrence of cracks due to drying shrinkage of the concrete.

In the intermittent synthetic slab bridge 10 of the embodiment, the thickened flange portion 9f is cut off from the slab concrete by the cap-shaped rubber plate 14, and the flange and the slab concrete are non-synthesized. No tensile force is generated in Therefore, the floor slab concrete 7 is prevented from cracking. Further, because of non-synthesis, a larger stress is generated in the upper flange of this section than in the normal flange section 9e, but a large bending resistance rigidity formed by the thickened flange section 9f and the lower flange 9b formed in this section. With this, the magnitude of the stress generated in the normal flange portion 9e can be made approximately the same.

[0021]

EFFECTS OF THE INVENTION According to the intermittent synthetic slab bridge of the present invention, corrosion and noise due to the seam of the slab of the simple girder bridge are prevented, and the occurrence of cracks that may occur in the slab concrete of the continuous girder bridge is prevented. It was possible to improve the durability.

[Brief description of drawings]

FIG. 1A is a vertical sectional view of an intermittent synthetic floor slab according to an embodiment of the present invention, FIG. 1B is a plan view of an upper flange, and FIG.
It is sectional drawing in the -A arrow direction.

FIG. 2A is a longitudinal sectional view of an intermittent synthetic floor slab bridge of another embodiment, FIG. 2B is a plan view of an upper flange, and FIG.
FIG.

FIG. 3A is a load diagram and FIG. 3B is a bending moment diagram when a uniformly distributed load is applied to a continuous beam having three spans.

FIG. 4 is a side view of an intermittent synthetic slab bridge.

[Explanation of symbols]

1 Concrete 2 Bridge Pier 3 Styrofoam 4 Fixed Bearing 5 Movable Bearing 6 Reinforced Concrete Horizontal Girder 7 Concrete 9 Steel Girder 9a Upper Flange 9b Lower Flange 9c Rib Protrusion 9d Amplification Flange 9e Normal Flange 9f Thickened Flange 10 Intermittent Composite Floor Bridge 11 12 Asphalt Pavement Wire mesh rebar 13 Plate rubber 14 Cap rubber 15 Stud

Claims (3)

[Claims] 1. In a multi-span intermittent synthetic slab bridge in which a steel girder and concrete form a non-synthetic slab on the intermediate bearing and a synthetic slab on the other part, the steel girder above the intermediate bearing The upper flange is formed to be wider than the upper flange of other parts, and plate-like edging material is attached to the upper and lower surfaces of the wide upper flange, and the upper flange other than the wide portion is prevented from shifting with concrete. An intermittent synthetic slab bridge characterized by having timber. 2. In a multi-span intermittent synthetic slab bridge in which a steel girder and concrete form a non-synthetic slab on the intermediate bearing and a synthetic slab on the other part, the steel girder above the intermediate bearing While forming the upper flange thicker than the upper flange of other parts, the upper surface and side surfaces of the thick upper flange are covered with a cap-shaped edging material, and the upper flange other than the thick part is made of concrete. An intermittent synthetic slab bridge that is equipped with anti-slip material. 3. The edging material is hard rubber, soft rubber,
The intermittent synthetic floor slab according to any one of claims 1 to 3, which is one or more materials selected from the group consisting of synthetic resins, fiber materials, and asphalt viscoelastic materials.