JP2004019385A - Structure of joining steel-concrete combined floor panel to its unit steel skeleton - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of joining a steel-concrete combined floor panel to its unit steel skeletons, allowing easy construction and preventing cracking resulting in corrosive deterioration without causing the shortage in filling a concrete. <P>SOLUTION: The unit steel skeletons 20A of the floor panel 20 are constructed with grooved-steel joint reinforcing beams 30 directed sideways to open to the side and fixed to the upper face of a bottom steel plate 21 at predetermined intervals approximately perpendicularly to a bridge shaft. The adjacent unit steel skeletons 20A are joined with a plurality of fastening mechanisms 40 provided at predetermined intervals along a joint line 20B. The fastening mechanisms fasten fastening plates erected on the joint edges of the bottom steel plate 21 and having a preset width in the direction perpendicular to the bridge shaft with fastening bolts. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steel-concrete composite slab that is a floor slab that constitutes a bridge or an elevated road, and is formed by integrating a steel skeleton and concrete into a strength composite.
[0002]
[Prior art]
As a floor slab that constitutes a bridge or an elevated road, an RC concrete layer having a predetermined thickness is formed on the upper side of a steel plate substrate member (steel skeleton) on which a synthetic coupling member such as a stud is erected, and the substrate member and the concrete layer A steel-concrete composite slab constructed by strength-synthesized is known.
[0003]
Such a steel-concrete composite slab is usually manufactured in a factory by manufacturing a unit steel skeleton body in which the steel skeleton is divided at least in the direction of the bridge axis, and the unit steel skeleton body is transported to the installation site and aligned on the girder. After the installation and arrangement, each unit steel skeleton is joined by a joining means, and a reinforcing bar is placed, and concrete is placed by a so-called half precast method.
[0004]
As a steel skeleton structure, in order to correspond to a long span recently, as shown in a conceptual perspective view of a steel concrete composite slab girder bridge 20 'to which one example is applied, FIG. A structure in which a reinforcing beam 30 'in a direction orthogonal to the bridge axis is disposed on the upper surface has been proposed.
[0005]
The steel skeleton of the illustrated steel-concrete composite slab 20 'has a large number of unillustrated dowels implanted by welding on the upper surface of the substrate member 21', and a reinforcing beam 30 'made of T-shaped steel orthogonal to the bridge axis. The substrate member 21 ′ functions as a mold, and the reinforcing beam 30 ′ is provided with a plurality of openings (not shown) formed in the abdominal plate, and the concrete layer 22 ′. It works as a strength member in the direction of the bridge. With such a structure, when placing the concrete forming the concrete layer 22 ′, there is no need for a lower formwork, and it is necessary to provide a support in order to maintain the shape on the girder with high rigidity. No construction is easy.
[0006]
In addition, as a coupling structure for coupling adjacent unit steel frame bodies during the construction of the steel frame, as shown in FIG. 9, a superposed arrangement is provided between the substrate members 21 ′ of the adjacent unit steel frame bodies 20 A ′. A steel plate coupling plate 22 ′ and a substrate member 21 ′ are fastened by a fastening member 23 ′ such as a bolt and a nut, and are coupled by a frictional force acting between the coupling plate 22 ′ and the substrate member 21 ′ (friction coupling) Structure) and, as shown in FIG. 10, the connecting ribs 21A 'each having a predetermined height standing on the edge of the substrate member 21' of the unit steel frame are fastened by fastening members 24 'such as bolts and nuts. There is something to do (tensile coupling structure: this is called because a tensile force acts on the fastening member).
[0007]
[Problems to be solved by the invention]
However, the conventional steel-concrete composite slab as described above tends to be insufficient in filling the lower portion of the upper flange of the reinforcing beam 30 'with the T-shaped steel fixed to the upper surface of the substrate member 21'. There was a problem of becoming. This tendency is particularly remarkable in the part on the hill side indicated by X in the figure when there is a gradient in the bridge axis direction as shown in FIG.
[0008]
Further, if a frictional coupling structure is adopted as the coupling structure of the unit steel frame, a scaffold is required, which is extremely troublesome. When the tensile coupling structure shown in FIG. 10 is applied, the coupling rib 21A ′ is in the direction perpendicular to the bridge axis. In order to be continuous, the thickness of the concrete layer 22 'on the upper side is reduced only at the relevant portion (tx <ta), so that there is a problem that cracks are likely to occur due to stress concentration. When cracks occur, the rainwater that enters from the cracks causes corrosion deterioration of the joints.
[0009]
The present invention has been made in view of the above problems, and does not cause a shortage of concrete filling, is easy to construct, and can prevent the occurrence of cracks that cause corrosion degradation. It aims at providing the connection structure of a floor slab and its unit steel frame.
[0010]
[Means for solving the problems]
In the steel-concrete composite slab of the present invention that achieves the above object, the unit steel frame bodies are arranged side by side on the main girder and joined together by a coupling means, and the concrete layer is integrated with the unit steel frame bodies to provide strength. A steel-concrete composite floor slab formed by synthesis, wherein the unit steel skeleton body is configured by fixing coupling reinforcing members at predetermined intervals on an upper surface of a substrate member constituting a lower surface of the floor slab. A plurality of fastening mechanisms, each of which is formed by fastening fastening plate members each having a predetermined width erected on the adjacent board member with fastening bolts, are provided along the coupling portion.
[0011]
In addition, the fastening mechanism includes a reinforcing rib that extends from both ends of the fastening plate member to the anti-bonding side.
[0012]
Furthermore, a disc-like spacer member is interposed between the opposing fastening plate members of the fastening mechanism.
[0013]
The combined structure of unit steel frames in the steel-concrete composite slab is that the unit steel frames are arranged side by side on the main girder and are connected by a connecting means, and the concrete layer is integrated with the unit steel frames and the strength is increased. In the combined steel-concrete composite slab, the coupling means is configured by arranging a plurality of fastening mechanisms along the coupling portion, and the fastening mechanism includes reinforcing ribs extending from both end edges of the fastening plate member. Fastening fasteners formed in this manner are fixed to the unit steel skeleton bodies that are coupled so that the fastening plate members face each other, and the fastening plate members of the opposing fastening fittings are fastened by fastening bolts. It is characterized by being.
[0014]
Further, a disc-shaped spacer member is interposed between the opposing fastening plate members of the fastening mechanism.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0016]
1 is a conceptual perspective view showing a bridge to which an example of a combined structure of a steel-concrete composite floor slab and its unit steel skeleton according to the present invention is applied, excluding a concrete layer, FIG. 2 is an enlarged view of a portion A, FIG. Is a cross-sectional view of the bridge (only one side is shown from the center), and FIG. 4 is a vertical cross-sectional view of the bridge.
[0017]
The illustrated bridge 1 includes a floor slab 20, which is a steel-concrete composite floor slab, supported by a girder set 10 including a steel main girder 11 and a cross girder 12.
[0018]
The girder 10 is configured such that a horizontal girder 12 is disposed at a predetermined interval between a pair of steel main girders 11 (only one is shown in FIG. 2) arranged on the left and right in the width direction. The steel main girder 11 and the cross girder 12 are each formed in an I-shaped cross section with a predetermined height by a steel plate, and the cross girder 12 is fixed to the belly plate of the steel main girder 11 at the end. A large number of stud dowels 13 are erected on the upper surface of the upper flange of the steel main girder 11, and these stud divers 13 are immersed in a concrete layer 22 (to be described later) of the floor slab 20 so that the steel main girder 11 (that is, the girder group 10). ) And the floor slab 20.
[0019]
The floor slab 20 is configured by integrally forming a concrete layer 22 having a predetermined thickness on a bottom steel plate 21 as a substrate member made of a steel plate having a predetermined thickness.
[0020]
The bottom steel plate 21 forms the lower surface of the floor slab 20 including the haunch portions on both sides of the support portion by the steel main girder 11, and on the upper surface, the coupling reinforcing beam 30 as a coupling reinforcing member is fixed at a predetermined interval in the bridge axis direction. A large number of stud dowels 23 are erected and these coupled reinforcing beams 30 and stud dowels 23 are immersed in the concrete layer 22 so as to be combined and integrated with the concrete layer 22 so that strength can be combined. The part corresponding to the steel main girder 11 is divided and divided into three parts (center plate 21C, side plates 21L, 21R) in the width direction. These divided center plate 21C, side plate 21L, 21R is connected and integrated by a joint reinforcing beam 30 continuous in the width direction.
[0021]
The opposed edges of the central plate 21C and the side plates 21L and 21R form a haunch portion 21a, and the outermost edge is placed on the upper surface of the side edge of the upper flange of the steel main girder 11 via a sealing material. ing. The leg portions of the gate-shaped connecting support plate 24 welded and fixed to the coupling reinforcing beam 30 are welded and fixed to the upper surfaces of the central plate 21C and the side plates 21L and 21R, respectively. The self-supporting strength at the time of concrete placement of 21a is secured. The space between the opposing edges of the central plate 21C and the side plates 21L and 21R is set at a distance corresponding to the upper flange of the steel main girder 11, and is erected on the upper flange of the steel main girder 11 through this space. The stud gibber 13 is immersed in the concrete layer 22 of the floor slab 20.
[0022]
The joint reinforcing beam 30 is formed on the bottom steel plate 21 at the side plate portion so that the U-shaped grooved steel having a side plate portion formed at a predetermined height on both sides of the bottom plate portion is laid down and opened in the bridge axis direction. It is fixed by welding and disposed over the entire width of the floor slab 20 so as to be orthogonal to the bridge axis direction. The opening direction is set toward the upper side of the slope when the bridge 1 has a gradient in the bridge axis direction. In addition, openings 31 having a predetermined diameter are formed at predetermined intervals in the longitudinal direction in the bottom plate portion that stands up at a right angle from the bottom steel plate 21.
[0023]
The stud dowels 23 are erected at predetermined intervals in a direction orthogonal to the bridge axis between the coupling reinforcing beams 30 arranged at predetermined intervals in the bridge axis direction.
[0024]
A reinforcing bar 24 that reinforces the concrete layer 22 is arranged above the joint reinforcing beam 30.
[0025]
As shown in the plan view of FIG. 5, the bridge 1 configured as described above is arranged by arranging the unit steel skeleton bodies 20A having a predetermined width in the bridge axis direction on the girder 10 and then connecting the unit steel skeleton bodies 20A. At the same time, reinforcing bars are arranged and concrete is placed to form a concrete layer 22 that is integrally coupled with the girder 10 and the unit steel skeleton 20A.
[0026]
The unit steel skeleton 20A is manufactured in a factory or the like by welding and fixing the joint reinforcing beam 30 and the stud diver 23 to the upper surface of the bottom steel plate 21 (center plate 21C, side plates 21L, 21R) having a predetermined width. It is transported to the site and installed.
[0027]
As shown in FIG. 5 and FIG. 6 which is an enlarged view of the B portion thereof, a plurality of unit steel skeleton bodies 20A adjacent to each other in the bridge axis direction are provided at predetermined intervals along a joint portion (a connecting line 20B orthogonal to the bridge axis). The fastening mechanism 40 is connected.
[0028]
The fastening mechanism 40 has a predetermined length from both edges of the fastening plate portion 41A as a fastening plate member having a predetermined height and width as shown in a plan view in FIG. 7A and a cross-sectional view in FIG. A planar U-shaped coupling bracket 41 formed by extending support ribs 41B as reinforcing ribs has a fastening plate portion 41A opposed to both adjacent unit skeleton plates, and the periphery of the fastening plate portion 41A and the support rib 41B. Are fixed to the bottom steel plate 21 and fastened by a fastening bolt 42 penetrating the fastening plate portion 41A and a nut 43 screwed thereto. That is, this coupling structure is a tensile coupling structure in which a tensile force acts on the fastening bolt 42. In the illustrated configuration, the coupling fitting 41 is formed by welding and fixing a support rib 41B having a predetermined length to a side plate portion of a predetermined length of the grooved steel. However, the coupling fitting 41 is not limited to this configuration. A steel plate may be bent and formed.
[0029]
Between the opposing fastening plate portions 41A, spacers 44 (three in the figure having the same thickness) as spacer members having a circular shape and a predetermined thickness as shown in FIG. 7C are interposed. Further, a square washer 45 as shown in FIG. 7 (C) fitted between the support ribs 41B is interposed between the fastening plate portion 41A and the head of the bolt head fastening bolt 42 or the nut 43. ing. In the figure, reference numeral 20C denotes a seal member that closes the gap between the connecting lines 20B.
[0030]
In such a coupling structure in which the fastening mechanism 40 is intermittently provided at predetermined intervals along the coupling line 20B of the unit steel skeleton 20A, the width along the coupling part (coupling line 20B) of the unit steel skeleton 20A. Since the connecting ribs are not erected over the entire direction, the thickness of the concrete layer 22 at the connecting portion is reduced little, and the occurrence of cracks due to stress concentration can be suppressed. Since the planar shape of the coupling fitting 41 is U-shaped and is welded to the bottom steel plate 21 at the periphery thereof, the welding length is long and can be firmly fixed, and a large coupling strength can be obtained.
[0031]
Further, since the spacer 44 is interposed between the opposing fastening plate portions 41A, the spacers 43 having different thicknesses are prepared and selected, or the interval between the coupling fittings 41A can be changed by changing the number of interposed members even with the same thickness. The error can be adjusted for absorption. Thereby, the precision of formation of unit steel frame 20A and attachment of fitting 41A can be eased, and manufacturing cost can be reduced. Furthermore, since the spacer 43 is circular, the concrete smoothly flows to the lower side of the concrete when it is placed and does not cause insufficient filling.
[0032]
【The invention's effect】
As described above, according to the steel-concrete composite floor slab according to the present invention, the unit steel skeleton is configured such that the coupling reinforcing members are fixed to the upper surface of the substrate member constituting the lower surface of the floor slab at predetermined intervals. The coupling means includes a plurality of fastening mechanisms formed by fastening fastening plate members each having a predetermined width, which are erected on adjacent substrate members, with fastening bolts. In addition to improving the rigidity of the member in the direction perpendicular to the bridge axis, it is possible to prevent insufficient filling of the concrete by setting the grooved steel to open toward the hill when there is a gradient in the bridge axis direction. Since the fastening mechanism is intermittently provided along the connecting portion of the unit steel skeleton body, the thickness of the concrete layer of the connecting portion can be secured, and the occurrence of cracks due to stress concentration can be suppressed.
[0033]
In addition, the fastening mechanism includes a reinforcing rib extending from the both ends of the fastening plate member to the anti-bonding side, so that the welding length is long and can be fixed with a large strength. Strength can be obtained.
[0034]
Furthermore, a disc-shaped spacer member is interposed between the opposing fastening plate members of the fastening mechanism, so that spacer members having different thicknesses can be prepared and selected, or the same thickness can be selected. However, it is possible to absorb and adjust an error in the interval between the fastening plate members by changing the number of interposed members. Thereby, it becomes possible to relieve the precision of formation of a unit steel frame and attachment of a fastening plate member, and can reduce manufacturing cost. In addition, since the spacer member is circular, the concrete smoothly flows to the lower side when the concrete is placed, so that insufficient filling is not caused.
[0035]
In addition, as a united steel frame structure in the steel-concrete composite floor slab, the unit steel frame bodies are arranged side by side on the main girder and connected by a connecting means, and a concrete layer is integrated with the unit steel frame body. In the steel-concrete composite floor slab that has been strength-combined, the coupling means comprises a plurality of fastening mechanisms arranged along the joint, and the fastening mechanism has reinforcing ribs extending from both ends of the fastening plate member. The fastening brackets formed are fixed to the unit steel frame bodies that are coupled with the fastening plate members facing each other, and the fastening plate members of the opposing fastening brackets are fastened by fastening bolts. The fastening mechanism is provided intermittently along the connecting part of the unit steel skeleton, so that the thickness of the concrete layer of the connecting part can be secured and the occurrence of cracks due to stress concentration can be suppressed. It can be. By comprising the reinforcing ribs extending from the both ends of the fastening plate member to the anti-bonding side, the weld length is long and can be fixed with a large strength, and as a result, a large coupling strength can be obtained.
[0036]
Furthermore, a disc-shaped spacer member is interposed between the opposing fastening plate members of the fastening mechanism, so that spacer members having different thicknesses can be prepared and selected, or the same thickness can be selected. However, it is possible to absorb and adjust an error in the interval between the fastening plate members by changing the number of interposed members. It becomes possible to relax the accuracy of forming the unit steel frame and attaching the fastening plate member, and the manufacturing cost can be reduced. In addition, since the spacer member is circular, the concrete smoothly flows to the lower side when the concrete is placed, so that insufficient filling is not caused.
[Brief description of the drawings]
FIG. 1 is a conceptual perspective view showing a bridge to which an example of a combined structure of a steel-concrete composite floor slab and its unit steel skeleton according to the present invention is applied, excluding a concrete layer.
FIG. 2 is an enlarged view of a portion A in FIG.
FIG. 3 is a cross-sectional view of a bridge.
FIG. 4 is a longitudinal sectional view of a bridge.
FIG. 5 is a plan view showing an installed state of a unit steel skeleton.
6 is an enlarged view of a portion B in FIG.
7A is a plan view, FIG. 7B is a sectional view, FIG. 7C is a spacer, and FIG. 7D is a square washer.
FIG. 8 is a perspective view conceptually showing a steel concrete composite slab as a conventional example.
FIG. 9 is a cross-sectional view showing a friction coupling structure of a unit steel skeleton.
FIG. 10 is a cross-sectional view showing a tensile bond structure of a unit steel frame.
FIG. 11 is an explanatory diagram of insufficient filling of concrete under the reinforcing beam.
[Explanation of symbols]
1 Bridge 10 Girder 11 Main girder 20 Floor slab (steel-concrete composite slab)
20A Unit steel skeleton 20B Bond line (bonding part)
21 Bottom steel plate (substrate member)
22 Concrete layer 30 Bond reinforcement beam (bond reinforcement member)
40 fastening mechanism 41A fastening plate part (fastening plate member)
41B Support rib (Reinforcement rib)
42 Fastening bolt 44 Spacer (Spacer member)

Claims (5)

A steel-concrete composite slab in which unit steel skeleton bodies are arranged side by side on the main girder and joined together by a coupling means, and a concrete layer is integrated with the unit steel skeleton body and strength-synthesized.
The unit steel skeleton is configured by fixing coupling reinforcing members at predetermined intervals on the upper surface of the substrate member constituting the lower surface of the floor slab,
The coupling means is constituted by a plurality of fastening mechanisms formed by fastening fastening plate members each having a predetermined width, which are erected on adjacent substrate members, by fastening bolts, along the coupling portion. Steel concrete composite floor slab. The steel-concrete composite floor slab according to claim 1, wherein the fastening mechanism includes reinforcing ribs extending from both ends of the fastening plate member to the anti-bonding side. 3. The steel-concrete composite slab according to claim 1, wherein a disk-shaped spacer member is interposed between the opposing fastening plate members of the fastening mechanism. In the steel-concrete composite floor slab in which unit steel skeleton bodies are arranged side by side on the main girder and joined together by a coupling means, and a concrete layer is integrated with the unit steel skeleton bodies and strength-synthesized,
The coupling means includes a plurality of fastening mechanisms arranged along the coupling portion,
The fastening mechanism is configured such that fastening metal fittings in which reinforcing ribs are extended from both end edges of the fastening plate member are respectively fixed to the unit steel frame bodies that are coupled so that the fastening plate members are opposed to each other, and the opposing fastening is performed. A unit steel skeleton joint structure in a steel-concrete composite floor slab, wherein a fastening plate member of a metal fitting is configured to be fastened by a fastening bolt. The unit steel skeleton coupling structure according to claim 4, wherein a disk-shaped spacer member is interposed between the opposing fastening plate members of the fastening mechanism.

Images