JPS6131510A - Construction of cable of suspension bridge - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for constructing suspension bridge cables.

[Prior art]

Conventionally, the suspension bridge cable construction method was about 100
The main wires are bundled together and attached to sockets at the ends to form a strand of a predetermined length, which is then wound onto a special reel and transported to the site, then set on an unreeler and unwound from the reel. The P-W-8 (parallel wire strand) method involves pulling out strands onto rollers on the floor of the scaffolding, and transporting the bare wire coils to the site using a spinning wheel with a diameter of approximately 1 m. The cables are hung on wheels, and the spinning wheels are used to move the wires from one side of the anchors on both banks to the other, and by repeating this process, approximately 500 wires are erected. The A-8 (air spinning) method is known, in which strands are bundled to form large diameter strands.

However, each of the above-mentioned conventional construction methods has the following drawbacks.

In the p-w-S method, after the strands are pulled out, each strand is temporarily pulled and relocated, and each saddle is shaped into a square shape, so the length of the suspension bridge is 4000 m.
The extremely long suspension bridge is temporarily closed.

The free-hang tension and temporary pulling stroke during relocation become thicker, and the length of the saddle groove also becomes longer, resulting in longer strand shaping work. For this reason, the work time required for temporary pulling, relocation, and shaping of each strand was approximately 4 hours.
If the operating time per day is 8 days, half a day will be spent on these tasks, resulting in a large amount of critical work for the PW and S construction methods.

Therefore, unless shortening the strand drawing time, that is, improving the drawing speed, does not lead to shortening the cycle time and process, there will be a noticeable drawback in terms of construction period when constructing long strands.

On the other hand, in terms of quality, if the strand length is as long as 4000 m, the quality may deteriorate due to sag, waviness, and birdcage in the vicinity of the saddle that occur when the strand is wound onto a reel or unwound from the reel.

Furthermore, the pulling out method is a tramway type, and the hauling rope and carrier run at a height of approximately 4 m above the floor of the suspended scaffold, so there is a risk of the hauling rope coming off due to vibration or loosening, and instability of the carrier due to wind. There are risks such as

Next, in the A, S construction method, the running speed of the spinning wheel can be increased to a maximum of approximately 240 m7 minutes, and the p,
Although it is possible to speed up the construction by approximately 6 to 8 times using the S construction method, the construction speed per unit of stem is slow because the construction is carried out in units of strands, and the operating rate is greatly reduced by wind. Safety also decreases.

[Purpose and structure of the invention]

The present invention is a construction method that completely overcomes the drawbacks of the conventional construction method described above, and aims to significantly shorten the construction period, improve strand quality, and provide high safety.The gist of this invention is , Anchorage 1 on both banks where suspension bridges should be constructed
A suspended scaffold 2 was erected in between, and a strand pull-out relocation device 6 was guided by a rail 4 installed on the floor of the suspended scaffold 2 and moved back and forth by a drive device, etc., and was installed behind the anchorage 1 on both banks. A large number of strands are gathered on-site by the strand concentrator 5 and are sheathed to form a small-diameter strand, and the strand pull-out transfer device B
The number of required steps is to pull out a small diameter strand from one bank onto the pull-out roller 6 on the suspended scaffold, and at the same time automatically transfer the small diameter strand that has already been pulled out from the other bank into the cable former 7. This method of constructing a suspension bridge cable is characterized by repeatedly bundling the small diameter strands that have been transferred to form a large diameter strand 8, and then attaching sockets 9 to both ends of the large diameter strand 8 to pull in and fix it. It is in.

〔Example〕

Next, the invention will be explained in detail using fully illustrated examples.

Figures 1 to 6 show examples in which the present invention is applied to the construction of a single suspension bridge cable. After installing Nui 71-10, which is about half the number of strands per cost land in the P-w S construction method, at the rear of Anchorage 1 on both banks, the same number of strand coils as the number of switches are installed. The wire convergence device 5 and the sheathing device 11 are set in the switches 1o on both banks, and in front of the switches 1o on both banks.

Next, the wire 1 is let out from the switch 1o on both banks.
The thin strands 16 are sheathed at a required pitch using the 7-zinc device 11.

Next, the tip of the small diameter strand 16 is connected to a drawer relocation device (rasoceller) 3 (a device that can perform drawer work and moving work at the same time), and the drawer relocation device 6 is attached to the floor of the suspended scaffold 2. The small-diameter strand 16 is moved onto the pull-out roller 6 installed on the floor of the suspended scaffold 2. Pull it out with the required tension.

After the first small-diameter strand has been pulled out from one bank to the opposite bank through the series of operations described above, the tip of this small-diameter strand is removed from the drawer transfer device 6, and the tip of the second small-diameter strand is attached to the drawer transfer device 6. By connecting and running the pull-out relocation device 6 in the opposite direction, this second small-diameter strand is pulled out with the required tension onto the pull-out roller 6 on the floor of the suspended scaffold 2 while performing on-site focusing and cleaning. At the same time, the first small diameter strand, which has already been drawn out, is automatically transferred from the drawing roller 6 into the cable former 7 by being guided by the plurality of inclined guide loops 14 and 15 in the drawing transfer device B. Here, the plurality of inclined guide sheaves 14 in the drawer relocation device 6
．． 15 can change the tilting force direction and the guiding direction depending on the running direction. As a means for changing the direction of the tilting force and the guide direction of the tilting guide sheave 14, 15, a means of changing the mounting may be adopted, or a method of attaching the tilting guide loops 14, 15 to a holding member and pulling out and relocating the holding member. The holding member may be attached to the frame of the apparatus so as to be able to change the tilting direction and the guiding direction, and a fixing device may be provided for fixing the holding member to the frame.

As described above, when the drawer transfer device 6 arrives at the bank on the drawer side of the first strand, it removes the tip of the second small diameter strand that has been drawn out from the drawer transfer device 6, and then
The tip of the thin strand is connected to the drawer relocation device B, and the sixth thin strand is pulled out toward the opposite bank while automatically transferring the second thin strand. In FIGS. 6 and 4, reference numeral 16 indicates a small diameter strand that has been moved into the cable former 7.

After repeating the drawer relocation process as described above a necessary number of times, the group of small diameter strands relocated in the cable former 7 is bundled to form a large diameter strand 8 that is equivalent to or larger than that of the A-8 construction method. Configure. After that, sockets 9 are attached to both ends of this large diameter strand 8 on site.
Both ends of the large diameter strand 8 are drawn into the anchorage 1 and fixed.

In addition, in FIG. 1 and FIG. 2, 17 is the main tower.

Figures 7 to 10 show an example in which the present invention is applied to the simultaneous erection of two suspension bridge cables.
-10, Element wire focusing device 5. Nzongu device 11. A common drawer relocation device 6, which has two parallel rows of drawer rollers 6 and cable formers 7 and is equipped with inclined guide sheaves 14 and 15 on both the left and right sides, can transfer the small diameter strands on both the left and right sides. The erection order is the same as in FIGS. 1 to 6, although they are configured to be done simultaneously.

Next, as a drive method for reciprocating the drawer relocation device 3, a method may be adopted in which the drive winch 18 installed on both banks reciprocates via the hauling rope 19, or a drive winch installed on the drawer relocation device 6 itself may be adopted. All methods may be adopted in which the drawer relocation device 6 can be moved back and forth on the rail 4 laid and fixed on the floor of the suspended scaffolding 2 using a drive device or the like.

The drive system is not located at a height of about 4 m from the floor of the suspended scaffold 2 like the conventional tramway system, but if it is installed at a height of about 1 m from the floor of the suspended scaffold 2, the vibration of the hauling rope can be reduced. Safety is also greatly improved because there is no chance of the rope coming off due to loosening or loosening, and there is no instability due to the wind that occurs when the rope is at a higher elevation.

〔Effect of the invention〕

Since this invention is configured as described above, P-W,
It is possible to eliminate the above-mentioned critical work in the S method, and therefore the cycle time can be greatly shortened, and when the drawer relocation device B runs one way, it is possible to pull out small diameter strands and to remove the strands that have already been pulled out one cycle before. Since the relocation and relocation are performed at the same time, the cycle time can be further shortened.Moreover, the critical work in the erection method of this invention is the pulling out and relocation work itself, so the improvement in speed directly leads to a reduction in the cycle time. The construction period can be significantly shortened, and in terms of quality, since the strands are drawn directly from the switch 10 and then made into small diameter strands, there is no waviness or sag in the strands that may occur with the P, W, or S methods. , Birdcage.

This has the effect of reducing quality deterioration due to twisting, etc.

Furthermore, 1) there is no need for large reels for transporting the strands, special transport equipment, etc., which are required in the W and S methods.

In addition, in this construction method, the strand length is adjusted on site, so
Gauge wire required in p, w, s method is not required, and p
The number of shim plates used to adjust the strand length of the , w, and s construction methods on site can be reduced. Furthermore, since it is easy to increase the diameter of the strand, it can be made as small as the Anchorage '1A-8 construction method or even smaller. Inside each saddle, there are many effects such as reducing the number of spacers, and especially in the case of ultra-long suspension bridge cables, the effects are extremely large.

[Brief explanation of drawings]

Figures 1 to 6 show an example in which the present invention is applied to the construction of one suspension bridge cable. Figure 1 is a schematic side view showing the whole, and Figure 2 is a left side view of Figure 1. FIG. 6 is a schematic plan view with the anchorage and main tower omitted in FIG. 1, FIG. 4 is an enlarged plan view of the left side of FIG. 3, and FIG. FIG. 6 is a perspective view showing a relocation situation using the drawer relocation device, and a schematic front view thereof. Figures 7 to 10 show an example in which the present invention is applied to the simultaneous erection of two suspension bridge cables, with Figure 7 being a schematic plan view and Figure 8 being an enlarged view of the left side of Figure 7. FIG. 9 is a perspective view showing the relocation situation by the drawer relocation device, and FIG. 10 is a schematic front view thereof. In the figure, 1t/'i eye college, 2 is suspended scaffolding, 6
1 is a strand drawing transfer device, 4 is a rail, 5 is a wire concentrator, 6 is a drawing roller, 7 is a cable former 18
is a thick diameter strand, 9 is a socket, 10 is a switch, 1
1 is a sheathing device, 12 is a wire, 16 is a thin diameter strand, 14 and 15 are inclined guide sheaves, and 18 is a driving winch.

Claims (1)

[Claims] A suspended scaffold 2 is erected between the anchorages 1 on both banks where a suspension bridge is to be constructed, and a strand pull-out transfer device 3 is guided by a rail 4 installed on the floor of the suspended scaffold 2 and moved back and forth by a drive device, etc. A large number of strands are gathered on site using a strand converging device 5 installed behind the anchorage 1 on the shore, and a small diameter strand is formed while sheathing.
The strand pull-out transfer device 3 pulls out a small diameter strand from one bank onto the pull-out roller 6 on the suspended scaffold, and at the same time automatically transfers the small diameter strand already pulled out from the other bank into the cable former 7. The transfer process is repeated as many times as necessary, and then each small diameter strand that has been transferred is bundled to form a large diameter strand 8, after which sockets 9 are attached to both ends of the large diameter strand 8 and the sockets 9 are pulled in and fixed. A method for constructing suspension bridge cables.