JPS603563B2 - Cable support method for cable-stayed bridge towers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable support construction method for a cable-stayed bridge in which cables c are stretched between towers a and girders b, as shown in FIG.

Conventionally, in order to support the cable c on the tower a, a saddle d having an arcuate support surface is fixed to the tower part as shown in FIG. 2, and the cable c is stretched over the saddle d, or As shown in FIG.
As shown in the figure, a method has been proposed in which each end of the left and right cables c is anchored via a fixing part f.

However, in the method shown in Fig. 2, the saddle d moves due to the difference in tension T,, T2 between the left and right cables c, and in the method shown in Fig. 3, the saddle d moves due to the difference in tension between the left and right cables c. The movement of d causes an eccentric bending moment in the cable a, and in the method shown in FIG. 4, the tension difference between the left and right cables c causes the cable to sag.

The present invention was proposed in order to eliminate such drawbacks, and the main cable is suspended over a saddle that is rotatably supported by a saddle support beam that is installed to be able to rise and fall freely. Both ends of the cable-stayed bridge tower are fixed to girders, and then the saddle support beam is lifted along the tower to introduce a required tension to the cable, and then the saddle support beam is fixed to the tower. This is related to the cable support method in the section. In the present invention, since the saddle support beam to which the saddle is rotatably mounted is installed on the tower so that it can be raised and lowered, the main cable is stretched over the rotating saddle and both ends of the saddle are anchored to the girder. By hoisting the saddle support beam along the tower, the required tension can be introduced into the main cable.

Therefore, by fixing the saddle support beam to the tower in this state, the girder is firmly supported by the tower via the main cable. In the present invention, as described above, since the saddle is rotatably supported by a saddle support beam that is attached to the tower so that it can be raised and lowered, the tension on both left and right sides of the main cable spanned over the saddle is always maintained. Equally, the difference in tension between the left and right cables does not cause mirroring on the tower, nor does it create mirroring like in conventional saddles, and tension can be applied to the cables by moving the saddle support beam up and down. It can be easily adjusted.
The present invention will be described below with reference to the illustrated embodiments.

Reference numeral 1 denotes a tower, and guide rails 2, which also serve as saddle support beam fixing materials, are fixed in the vertical direction on both the left and right sides of the tower, and a saddle support beam 3 is mounted along each of the guide rails 2 so as to be able to move up and down.

A cylindrical saddle 5 is rotatably mounted on the receiving beam 3 via a rotating shaft 4. Incidentally, the outer periphery of the saddle 5 is provided with grooves for connecting cables. Then, as shown in FIGS. 6 and 7, the main cable 6 is spanned over the saddle 5 and sent out using this, and both ends are anchored to the girder 7.

In the figure, 8 is a winch, and 9 is an anchorage. Next, from the top of the mountain, the saddle support beam 3 is lifted along the guide rail 2 using the Egami equipment 10 such as a winch, a hipper, and a jack, thereby introducing the required tension to the main cable 6 (see Fig. 8). ) In this state, the saddle support beam 3 is fixed to the guide rail 2 via the high-tensile bolt 11.

(See FIG. 9) Although the present invention has been described above with reference to embodiments, the present invention is of course not limited to such embodiments, and various design modifications can be made without departing from the spirit of the present invention. It is something that can be done.

[Brief explanation of the drawing]

Fig. 1 is a side view of the cable-stayed bridge, Figs. 2 to 4 are front views showing conventional cable support devices on the tower side, Fig. 5 is an explanatory view of the operation of the saddle shown in Fig. 2, and Fig. 6 is a side view of the cable-stayed bridge. Figures 9 to 9 are front views showing the steps of an embodiment of the construction method of the present invention;
The figure is a front view of the saddle portion used in the method of the present invention, FIG. 11 is a side view thereof, and FIG. 12 is a plan view thereof. 1... Tower, 2... Guide rail, 3... Saddle support beam,
5...Saddle, 6...Main cable, 11...
...High tension bolt. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] 1. A main cable is spanned over a saddle that is rotatably supported by a saddle support beam that is mounted on a tower so that it can be raised and lowered, and both ends of the cable are fixed to girders, and then the saddle support beam is hoisted along the tower. A method for supporting cables in a tower section of a cable-stayed bridge, characterized in that the saddle support beam is fixed to the tower after a required tension is introduced into the cable.