JP2003336216A - Composite suspension floor slab and method for construction thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technique in which high flexural rigidity and high torsional rigidity are imparted to the structure of the lower floor slab of a deck type prestressed-concrete suspension bridge. <P>SOLUTION: In a composite suspension floor slab 10, composite steel pipes 20 in which steel pipes 21 for a general structure are covered with a high toughness cement composite material 22 are used as left-right suspension main cables, and the composite suspension floor slab has composite floor slabs 30 composed of steel plates 31 covered with the high toughness cement composite materials 32 of upper-lower two layers horizontally connecting the composite steel pipes 20. PC steel materials are inserted into inserting holes 23, and used as the lower floor slab of the suspension bridge. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composite hanging floor slab and a method for constructing the same. More specifically, the lower floor slab is a prestressed main cable with a catenary wire, and is a constituent material of the lower floor slab of an upper road type PC suspension bridge having a horizontal upper deck via a vertical member above the cable. The present invention relates to a composite hanging floor slab having high torsional rigidity and a method for constructing the same.

[0002]

2. Description of the Related Art Regarding the upper road type PC suspension bridge, the present applicant has disclosed a basic technique in Japanese Patent Laid-Open No. 54-160027. This is, for example, a lower floor slab spanned between abutments or bridge piers, a number of vertical members as compression members arranged at intervals on the lower floor slab, and a series of above-mentioned vertical members between abutments or piers. It is an upper road type prestressed concrete suspension bridge consisting of an upper deck mounted on a member and a lower deck made of prestressed concrete with a built-in main cable.

The inventors of the present invention applied for a basic structure in which a high-toughness cement composite material and a steel member are combined.
In the 001-228404 application, a member having a two-layer integrated structure of steel and short fiber reinforced concrete was provided.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an improvement of the above-mentioned upper road type prestressed concrete suspension bridge, and provides a technique for imparting high bending rigidity and high torsional rigidity to the structure of the lower floor slab. The purpose is to That is, a composite hanging floor slab having high bending rigidity and high torsional rigidity has been developed as a structure that makes the best use of the excellent characteristics of the two-layer integrated structural member of the above steel material and short fiber reinforced concrete, and construction using this It is intended to provide a method.

[0005]

SUMMARY OF THE INVENTION The present invention is a composite hanging floor slab structure characterized by taking the following technical means. That is, the present invention, the rigid structural element covering the general structural steel pipe with a high toughness cement composite material as the left and right suspension main ropes,
A composite suspended floor slab, comprising upper and lower two-layer connecting members for connecting the steel pipes of the left and right suspension main ropes, the connecting members being made of a steel plate coated with a high-toughness cement composite material. Here, the high-toughness cement composite material is a cement composite material having high strength and toughness such as short fiber reinforced concrete.

Next, the method for constructing the composite hanging floor slab of the present invention is as follows.
A left and right steel pipe of unit length is connected by two upper and lower steel plates, and a steel pipe and steel plate are coated with a high-toughness cement composite material to manufacture a composite hanging floor slab unit, and a PC is attached to the end of the steel pipe.
A spacer for holding the insertion position of the cable is attached, a large number of the composite hanging floor slab units are connected in the axial direction of the steel pipe to insert the PC cable, and the PC cable is installed between the supporting portions.
This is a method for constructing a composite suspension floor slab, characterized in that the steel pipe is grounded after the action of the weight of the bridge body.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 7 shows a side view of the prestressed suspension bridge 50. The suspension bridge 50 is a bridge in which an upper deck 52 is erected via a vertical connecting member 53 on a lower floor slab 51 having both ends supported by supporting portions 54 in a catenary manner by introducing prestress. Valley 5
It is a suspension bridge installed on top of No. 6, but it is not necessary to install a main tower on both banks like ordinary suspension bridges. The support portion 54 is fixed by a retainer 55. The composite hanging floor slab 10 of the present invention forms the lower floor slab 51.

FIG. 1 is a diagram showing a composite hanging floor slab 10 according to an embodiment of the present invention. The composite suspension floor slab 10 of the present invention uses left and right composite steel pipes (synthetic structural elements) 20 in which a general structural steel pipe 21 is coated with a high-toughness cement composite material 22 and a composite floor slab (connecting member) 30 for connecting the same. .

In the composite steel pipe 20 in which the general structural steel pipe 21 and the high-toughness cement composite material 22 are combined, as shown in FIG.
Designed to address shear shear by providing 5. The height of the beads 25 is 2 to 3 mm, and the distance between them is 3
It was set to 0 to 40 mm. The coating thickness of the high-toughness cement composite material 22 is about 15 to 25 mm.

The composite hanging floor slab structure of the present invention has improved bending rigidity and torsional rigidity due to the combined effect of the steel pipe 21 and the high-toughness cement composite material 22. A spacer 24 of PC steel is provided at the end of the steel pipe. The steel pipe 21 is filled with cement milk after the action of the weight of the bridge body.

A composite floor slab 30 is used as a connecting member of the hanging floor slab. As shown in FIG. 3, the composite floor slab 30 comprises a high-toughness cement composite material 3 in which a dowel 37 is planted on the surface of a steel plate 31.
2 is attached. The composite floor slab 30 is composed of upper and lower two layers, and a high toughness cement composite material coated steel pipe 20 which is the main rope
Join with. For joining, a connecting material 41 such as steel, reinforced concrete or high toughness cement composite material is used.
Continuous beads or stud dowels 37 are provided on the surface of the steel plate 31 of the composite floor slab 30 in advance. The high-toughness cement composite material-coated steel pipe 20 and the composite floor slab 30 are attached in advance at the factory to form an integrated composite floor slab unit. This composite hanging floor slab unit is carried into the site, and a large number of composite hanging floor slab units are connected in the longitudinal direction at the site. The joints of the composite suspended floor slab unit will be constructed with high toughness cement composite material or reinforced concrete.

According to the present invention, since the bending and torsional rigidity of the composite hanging floor slab are higher than those in the case of using the concrete having the entire cross section, the composite hanging floor slab can be applied to the hanging slab bridge having a large span-sag ratio. The span-sag ratio is a value obtained by dividing the span length by the central hanging height (sag), which is usually around 40,
It can be set to 60 to 70 by using the composite hanging floor slab of the present invention. Since such a large span-sag ratio is obtained, the amount of deformation is small. Therefore, this bridge can be used for roads. Further, an upper deck 52 is provided on the lower floor slab 51.
For the purpose of structural simplification, the upper deck and the suspension deck will be separated structures.

The bending and torsional rigidity of the structural element of the present invention in which the outside of the steel pipe is coated with a high-toughness cement composite material is 200 m in diameter as compared with the structural element in which the steel pipe is filled with concrete.
It is about 1.5 times as large as about m-300 mmφ. This composite steel pipe is characterized in that the bending rigidity of the high-toughness cement composite material is compensated by a steel member to improve the flexural rigidity.

The result of the load test and the design load of the above composite steel pipe and composite floor slab will be described as follows.

The composite structure of the steel pipe and the high-toughness cement composite material can be a structural member having a higher design area than that of the steel tube alone. It has been confirmed by repeated ultimate load loading tests that this composite steel pipe has a high shear transmission capacity in the continuous bead portion.

A composite floor slab, which is a composite structure of a steel plate and a high-toughness cement composite material, has a thickness of 6 mm.
The steel plate high-toughness cement composite floor slab on which a 5-mm high-toughness cement composite material is applied has a high elastic region and high fracture strength.

Next, a method of erection of the composite hanging floor slab according to the present invention will be described. As shown in FIG. 4, the composite hanging floor slab units 10a, 10b, ...
The C steel material 42 is inserted. The PC steel material 42 is arranged at a fixed position on the pipe cross section by the spacer 24 provided at the end of the steel pipe.
FIG. 5 is a vertical cross-sectional view showing a connection portion of the steel pipe 21, where the composite hanging floor slab units 10a and 10b are butted to face the end faces of the steel pipe 21, and the PC steel material 42 is inserted through the spacer 24 in the longitudinal direction of the steel pipe 21. The collar 27 is fitted to the end of the welded joint 28 and joined to the weld 28, and then the covering material 29 is applied.

FIG. 6 shows a joint portion of the steel plate 31 of the composite floor slab 30. A flange 34 is provided at an end of the steel plate 31, the flange 34 is connected by a bolt nut 35, and a covering material is provided thereon. 36 is applied and coated.

Next, both ends of the PC steel material 42 are fixed to the support portions, and the connecting body of the composite hanging floor slab unit is installed between the support portions.

[0021]

Since the composite hanging floor slab structure of the present invention is constructed as described above, it is possible to reduce its own weight and increase bending and torsional rigidity. Further, due to the effect of the high toughness cement composite material, it has excellent durability. Furthermore, since the cracks due to deformation are dispersed as fine microcracks, the cracks in the concrete peculiar to the suspension floor slab are not localized, which is economical. Since a ready-made steel pipe or steel plate is used, a single-sided mold is unnecessary. It is also easy to process.
Since the members are light when assembled, the work is easy. Since the self-weight can be reduced, the main ropes, anchors, and abutments can be made small, and the excellent effect of economic efficiency is achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a suspended floor slab of an example.

2A is a perspective view of a steel pipe, and FIG. 2B is a sectional view thereof.

FIG. 3 is a sectional view showing a composite structure of a steel plate and a high-toughness cement composite material.

FIG. 4 is an explanatory diagram of an erection process.

FIG. 5 is a sectional view showing a structure of a joint portion of a steel pipe.

FIG. 6 is a sectional view showing a structure of a joint portion of a steel plate.

FIG. 7 is an explanatory diagram of a prestressed suspension bridge.

[Explanation of symbols]

10 Suspended floor version 20 Composite steel pipe (synthetic structural element) 21 steel pipe 22 High toughness cement composite material 23 holes 24 spacer 25 beads 26 Spacer 27 colors 28 Welding 29 coating 30 Composite floor slab (connecting member) 31 steel plate 32 High toughness cement composite material 33 Gibel 34 flange 35 bolt nut 36 coating material 41 Connecting material 42 PC cable 50 prestressed suspension bridge 51 Underfloor 52 Upper deck 53 Vertical connection member 54 Support Department 55 copy 56 valley

Claims (2)

[Claims] 1. A rigid structural element obtained by coating a general structural steel pipe with a high-toughness cement composite material as left and right suspension main ropes, and comprising upper and lower two-layer connecting members for connecting the steel pipes of the left and right suspension main ropes, The composite hanging floor slab, wherein the connecting member is made of a steel plate coated with a high-toughness cement composite material. 2. A composite suspension floor slab unit in which two right and left steel pipes having a unit length are connected by upper and lower two-layer steel plates, and the steel pipes and the steel plates are coated with a high-toughness cement composite material. A spacer that holds the insertion position of the PC cable is attached to the end, a large number of the composite hanging floor slab units are connected in the axial direction of the steel pipe, the PC cable is inserted, and the PC cable is erected between the support parts to form a bridge. A method for constructing a composite suspended floor slab, comprising: grounding the steel pipe after the self-weighting of the steel pipe.