JPH0194103A - Blique material of oblique tensioned bridge - Google Patents

Abstract

PURPOSE: To provide a diagonal member for a diagonally stretched bridge which is lightweight and allows corrosion prevention over a long period by using a connected pipe connected with fiber-reinforced synthetic resin tubes tapered at the terminal by socket tubes tapered at the terminal as the protective pipe of a support cord. CONSTITUTION: A connected pipe connected with fiber-reinforced synthetic resin tubes 6 tapered at the terminal by socket tubes 5 tapered at the terminal is used as the protective pipe 4 of the support cord 3 of a diagonally stretched bridge. The protective pipe 4 can be freely colored and is favorable to beautiful appearance, and it can be made maintenance-free over a long period when its surface is coated with a weather-resistant paint such as a fluororesin paint.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to cable-stayed bridge stay members.

[Prior Art] Steel wires called strands are used as the main structural member of the struts used for the stay members of cable-stayed bridges. Since this strut is exposed outdoors, it is necessary to prevent it from corroding and breaking. For this purpose, a common method is to place a bundle of strands in a protective tube and then grout with mortar to prevent corrosion. Traditionally, steel pipes have been often used as these protective tubes, connected by screws or welding, and the outer surface often has an anti-corrosion coating. Another known method is to insert a strand bundle into a flexible polyethylene pipe in advance and roll it to the required length.

[Problems to be solved by the invention] When steel pipes are used, the weight of the pipes becomes large, which places a large load on the overall structure of the bridge, and the lifting device used when connecting and constructing the pipes also needs to withstand a large amount of weight. It has to be something large-scale.

Furthermore, maintenance of repainting is essential for the anticorrosive coating on the outside of the pipe. On the other hand, the method of using plastic outer tubes such as polyethylene and constructing them in continuous rolls is suitable for small-scale bridges, but for large-scale bridges, there are limitations on the size of continuous rolls and the need to make them into rolls. There is a restriction on the size of the strand bundle, and from the viewpoint of weather resistance, the outer surface of the tube cannot be colored freely, and it is necessary to stabilize it by coloring it in a specific color such as black, which is desirable from an aesthetic point of view. There wasn't.

[Means for Solving the Problems] The present invention has been made in order to solve the above-mentioned problems, and the present invention has been made in order to solve the above-mentioned problems. In cable-stayed bridge cable members,
The present invention provides a cable-stayed bridge diagonal member characterized in that the protective tube is a connecting tube in which fiber-reinforced synthetic resin tubes each having a tapered end are connected by a socket tube having a tapered end.

As shown in Figure 1, a cable-stayed bridge has a structure in which a tower 1 and a main girder 2 are connected by a support cable 3 made of steel wire or the like. In order to protect this strut from corrosion due to outdoor exposure, fiber-reinforced synthetic resin (FRP) is used as the protective tube 4 in the present invention. The long struts can reach over 100 lengths, and the protection tube must be constructed by connecting FRP tubes of a predetermined length. In the present invention, this connection is made through a socket tube having a taper, such as an outer socket tube as shown in FIG. 2 and an inner socket tube as shown in FIG. 3.

When an outer socket tube is used, the end of the FRP protection tube is made into a convex taper and is joined by rubbing against the concave taper of the outer socket tube. When using an inner socket pipe,
The end of the FRP protection tube is made into a concave taper and is joined by rubbing against the convex taper of the inner socket tube.

The fitting portions of the tapers may be mutually planar inclined surfaces, or may be stepped or uneven surfaces that engage with each other. Alternatively, the connection may be performed by thread cutting. Usually, it is preferable to bond two planes together using an adhesive because it is simple and has a high bonding force.

It may be joined by bolting or the like.

Compared to the inner socket pipe, the outer socket pipe can be filled with grout up to a higher filling pressure of 20 kgf/cm2.
The grout material can be filled into about 100 m of connected protection pipes at once, resulting in high construction efficiency. Examples of the grout material include mortar made of cement, sand, lime, etc., so-called grout made by mixing cement with water, sand, etc., resin concrete, fiber-reinforced synthetic resin, and the like.

The protection tube and socket tube may be made of various hard synthetic resins, but in particular thermosetting resins such as vinyl ester resin, unsaturated polyester resin, epoxy resin, etc. reinforced with various fibers such as glass, carbon, and ceramics. is preferable from the viewpoint of strength and rigidity. Continuous pultrusion using continuous fibers (for example, glass roving or carbon fiber tow) as the reinforcing fiber is particularly preferred as a manufacturing method for protective tubes and socket tubes, as it is highly productive and has excellent tensile strength. To provide a taper on the protective tube or socket tube obtained by continuous pultrusion, a cutting method or a method of press-forming the resin at an uncured stage may be used. In addition to pultrusion molding, filament winding molding may be employed, and in this case, a taper can be provided without cutting or pressing.

[Effects of the Invention] By using an FRP pipe as a protection pipe, a corrosion prevention method that is lightweight and can withstand long-term outdoor exposure becomes possible. Moreover, coloring is free and aesthetically pleasing. Furthermore, by applying a weather-resistant paint such as a fluororesin paint to the surface, the pipe body will not be corroded, so it can be maintenance-free for a long period of time.

When using FRP pipes, it is necessary that the pipes be connected easily. In the present invention, this can be easily done by using the socket connection method.

[Brief explanation of the drawing]

Figure 1 is a schematic front view of a cable-stayed bridge showing the relationship between tower 1, main girder 2, and support cables 3, and Figures 2 and 3 are FRP protection pipes (6 or 8).
A schematic sectional view showing the relationship between the socket pipe (5 or 7) and the socket pipe (5 or 7). 4--Protection tube to protect one branch cable

Claims (1)

[Claims] 1. In a cable-stayed bridge cable member in which a support cable, a protective pipe that protects it, and a grout material that connects these are integrally formed,
1. A cable-stayed bridge diagonal member, characterized in that the protective tube is a connecting pipe in which fiber-reinforced synthetic resin tubes each having a tapered end are connected by a socket tube having a tapered end.