JPH0414204B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to the use of a cat walk rope, which is required for installing a cat walk, which is a work scaffold, in the construction of a long suspension bridge, particularly in the cable work thereof. When constructing a span, we have improved the temporary tensioning method for fixing the rope to the girder, and in particular, we have made the clamp structure smaller and lighter, improving handling, work efficiency, and work stability, shortening the construction period, Regarding things that made it possible to reduce construction costs.

(Prior art) Catwalks, which serve as work scaffolding, are indispensable in construction of long suspension bridges, especially in the cable work. Main rope (hereinafter referred to as cat walk rope)
It is known that the rope is temporarily pulled by a temporary pulling device provided at the top of the tower when the rope is stretched and the end socket of the rope is attached to the cat walk rope fixing girder. The temporary tensioning method is carried out as follows. That is, the examples shown in Figures 7 and 8 show the general configuration of a cat walk, and as shown in Figure 7, the cat walk 1 consists of main towers 2, 2 and anchors, which are the basic structure of a long suspension bridge. Cat walk rope 4 which is the main rope installed across the center span and side span of sections 3 and 3, storm rope 5,
A floor assembly 7 as shown in Figure 8 is mounted within a rope suspension frame using hanger ropes 6 etc. that connect both ropes, and the floor assembly 7 also has 9 wire nets on a bottom frame 8 as is known. It consists of a floor surface on which wire meshes 10 are laid, and both side surfaces on which wire meshes 9 and 10 are similarly stretched on the inner surface of a side frame 12 with hand ropes 11.
In the figure, 13 indicates a main cable. When constructing the canopy 1 using various ropes and flooring materials, first, the construction of the canopy rope 4 is started in the span.
In the process of this rope erection work, the terminal sockets 14 fixed to the four ends of the cat walk ropes stretched across the span are connected to the cat walk connected to the top side of the main tower 2, as shown in Fig. 1. There is a fixing operation for attaching to the rope fixing girder 15 (the figure shows a state in which the terminal socket 14a of the existing cat walk rope 4a is attached to the fixing girder 15). When performing this fixing work, please use the existing cat walk rope 4 in the same figure.
As shown as a cat walk rope 4 above the main tower 2, a temporary tension clamp 16 is used to hold the rope 4 at a position several meters to more than ten meters away from the tip of the rope 4 having the terminal socket 14. Top vent 17
A temporary rope 19 that can be freely wound and unwound from a temporary tension device 18 installed above is attached to the temporary tension clamp 1.
6 and pulls in the cat walk rope 4 through the winding of the temporary pull rope 19, the tension is released from the end of the rope between the temporary pull clamp 16 and the terminal socket 14, and the rope is free. The end of the rope in the free state is suspended by the hanging hook 20 of the top crane (not shown) to facilitate handling, and the terminal socket 14 is attached to the fixing girder 15, and then the temporary rope 19 is suspended.
Gradually unwind and loosen the tension, transfer all the tension to the cat walk rope 4 side, and then tighten the temporary tension clamp 1.
By removing the rope 6 from the rope 4 side, the erection of the catwalk rope 4 to the main tower 2 side is completed, and the work process using the temporary tensioning device 18 is the conventional temporary tensioning method. The temporary tensioning clamps 16 used in this temporary tensioning work include a bolt tightening type temporary tensioning clamp 16a shown in FIG.
A multi-stage wedge-shaped temporary clamp 16b shown in the figure is known, and a fixing girder 15, as shown in FIG. 9 showing a general type thereof, is known.
The temporary tension clamp 16a shown in FIG. 2 is of a two-piece type that can be detached, assembled and disassembled by a pair of clamp pieces 21, 21, and each clamp piece 21 has a recessed hole 22 for holding the rope 4 at a corresponding position. It consists of a main body 23 with a handle and a connecting part 25 having a connecting hole 24 for connecting with the temporary rope 19, and connecting holes 28, 28 with fastening bolts 26 and nuts 27 are provided at the upper and lower positions of the main body 23 sandwiching the holding recessed hole 22. It has a structure in which the cat walk rope 4 is sandwiched from both sides and the clamping force on the rope 4 is obtained by the axial force introduced into the fastening bolt 26. The clamp 16b is
A plurality of U-shaped bolts 30 are arranged in a row on the main plate 29 so that both U-shaped ends are inserted through the U-shaped bolts 30.
A receiver 31 is arranged on the bent part to serve as a receiver for the cat walk rope 4, and the main plate 29
By arranging the pressing portions 32 in a row on the lower surface of the main plate 29, the rope 4 is held between the pressing portions 32, and both U-shaped ends of the bolt 30 are inserted through the upper surface of the main plate 29, and wedge surfaces 33a and 34a that engage with each other are formed. The wedge plates 33 and 34 formed in multiple stages are arranged in an overlapping manner, and both U-shaped ends of each bolt 30 can be fastened with nuts 35, 35, thereby making it possible to clamp using the wedge engagement surfaces. 36 is a connecting part with the temporary rope 19 having a connecting hole 37 (for details, see Utility Model Application No. 51-82854, filed by Nippon Steel Corporation, Utility Model Application No. 59-41213). (No.). The fixing girder 15 of the cat walk rope 4 shown in FIG. 40, 41, an eye bolt type connecting shaft 42 with a connecting part 43 is attached to the girder frame 39 at the front end, and three cat walk ropes in the illustrated example extend over the remaining girder frames 40, 41. 4 are retained via anchorage in their respective terminal sockets 14. The connecting portion 43 of the connecting shaft 42 is connected to a universal joint 46 that is pivotally supported to a fixing metal fitting 44 on the tower top side via a pin shaft 45. 48 indicates a fastening nut.

(Problems to be Solved by the Invention) The above-mentioned temporary construction method in the prior art has the following major problems. In other words, in the case of a cat walk rope 4 such as the main rope used for the cat walk 1 installed in the span of a long suspension bridge, in the case of a super long suspension bridge with a span length of more than 1000 m, the rope diameter should be more than 70 mm. Since the rope 4 has a large diameter, the temporary tensile force required to fix the end of the rope 4 will naturally be excessive.
As is clear in the above-mentioned temporary tension method, when the temporary tension rope 19 is connected to the temporary tension clamp 16 for temporary tension, if the clamp 16 slips when the clamping force in the temporary tension clamp 16 is not sufficient, A large impact force acts on the temporary tension rope 19 and the temporary tension device 18 side, which not only creates a great danger, but also damages the surface of the clamp portion of the cat walk rope 4.
With the clamping means of a and 16b, sufficient clamping force cannot be obtained due to a decrease in clamping efficiency due to the following situation, and there is a concern that the clamp may easily slip. That is, the first is a decrease in the tightening force due to the initial creep of the fastening bolt, and the second is the difference in the diameter of the cat walk rope 4 between clamping (no stress) and temporary tension (tension is applied). The third factor is a decrease in the tightening force due to the apparent initial creep (reduction in diameter) in the radial direction of the cat walk rope, and the fourth factor is a decrease in the tightening force due to the apparent initial creep (reduction in diameter) of the cat walk rope. In order to deal with these situations, the clamping force must be increased. However, this requires measures such as increasing the number of fastening bolts and wedge plates, and as a result, the structure of the temporary tension clamp becomes more complicated and its shape and dimensions become larger. Unfortunately, the increased size and mass of clamps makes handling operations difficult.

(Means for Solving the Problems) The present invention solves the problems in the temporary tensioning method as described above, improves the clamp structure, enables smaller size and weight reduction, and ensures clamping force. By improving the
This system improves work safety and saves labor, resulting in shorter construction periods and costs.Specifically, it is used to install catwalks (work scaffolding) in the spans of long suspension bridge construction projects. In order to do this, a cat walk rope is stretched across the span, and before the end socket of the rope is attached to the cat walk fixing girder, the rope is temporarily pulled using a temporary pulling device installed at the top of the tower. For this purpose, a stopper crimped and fixed in advance by an alloy crimping means during rope manufacturing is stretched over a predetermined position on the end side of the above-mentioned cat walk rope having the terminal socket, and the temporary pulling rope in the temporary pulling device is stretched. At the site, the rope is locked to the stopper and connected to a joint fitting attached to the catwalk rope, and the rope part from the stopper to the terminal socket is freed through suction of the catwalk rope by the temporary pull rope, and The method is to attach a socket to the fixing girder.

(Function) According to the technical means of the present invention, as shown in FIGS. 4 and 5, first, in FIG. A stopper 50 is crimped and fixed together with an alloy crimping means on the rope portion at the position (see the same figure), such a cat walk rope 4 is stretched across the span, and the side opposite to the terminal socket of the stopper 50 is attached at the site. one end of 5
The joint fitting 51 consisting of two halves 51b and 51c is attached to the rope 4 so that one end 51a of the joint fitting 51 is locked at the end 51a of the joint fitting 51. This is done by fastening the split halves 51b and 51c, for example, with bolts 52. At this time, by forming and placing the connection part 53 of the temporary rope 19 on the two split halves 51b as shown in the figure, Eye part 1 of temporary rope 19
9a and the connecting portion 53 are removably connected, for example, by a jacket 54 or the like. In crimping and fixing the stopper 50 by the alloy crimping means, the fifth
As shown in the figure, a cylindrical stopper 50 made of an aluminum alloy material is generally manufactured by extrusion molding or the like. After placing a marking 55 at the mounting position of the stopper 50 shown in FIG. The stopper 50 is attached to the rope 4 under more even pressure.
Thus, the stopper 50 is integrated into a predetermined position of the rope 4 as shown in FIG. It is done in addition.

The stopper 50 installed in this manner has an extremely high slip resistance, and therefore, as illustrated in FIG. The rope 4 is stretched, and the temporary rope 19 is connected to the joint fitting 51 attached to the rope 4 at the site in a locking manner in contact with the stopper 50 in the same manner as shown in FIG. 19 to pull in the catwalk rope 4 and release the tension on the rope end portion side extending from the stopper 50 to the end socket 14 to make it easier to handle in a free state;
After suspending the above-mentioned end side with the hanging hook 20 of the top crane and attaching the terminal socket 14 to the side of the cat walk rope fixing girder 15, gradually loosen the pulled-in temporary rope 19 and reduce the tension on the rope. 4
The temporary pulling work can be completed by leaving the temporary pulling rope 19 and removing the joint fitting 51. That is, according to the present invention, the occurrence of clamp slippage is eliminated by eliminating the conventional temporary tension clamping means and using a means for connecting the temporary tension rope 19 with the stopper 50 and the joint fitting 51. In addition, the joint fitting 51 only needs to be securely connected to the rope 4, and there is no need to consider the sliding strength of this fitting itself, so it is also small and lightweight, and the overall structure is As a result, the clamp connection structure with the temporary pull rope side can be made significantly smaller, lighter, and simpler, and handling performance can be improved, work efficiency and work safety can be improved, construction period can be shortened, and construction costs can be reduced. It becomes.

(Example) A suitable example of the present invention will be described. The material of the stopper 50, which is crimped and fixed to a predetermined position of the rope 4 during factory manufacture of the catwalk rope 4, may be an aluminum alloy material commonly used in the alloy crimping method, but other materials may be used, such as those attached to the end of the wire rope. Eye-type end clamps and screw-type end clamps (not shown as they are already known)
It is also possible to use steel materials used in. Regarding the shape and dimensions of the stopper 50, a cylindrical sleeve type is appropriate due to the crimping process, and as shown in FIG. 5, the diameter of the sleeve is approximately twice the diameter d of the rope 4, that is
Approximately 2d is appropriate, and the length l may be set according to the required slip strength, and does not necessarily require the breaking strength of the rope 4. Also, the apparent size of the stopper 50 is reduced by crimping, so
It is extremely miniaturized, and there is no risk of any problem in winding up the rope 4 on a reel in a factory, pulling it out on site, constructing it, installing the catwalk floor assembly 7, etc. The span installation of the cat walk rope 4 is carried out using a known hauling rope and a carrier attached to the rope. In FIG. 6, 56 is a hauling rope,
57 indicates a rope carrier fixed to the rope. These are commonly used in conventional cable construction for long suspension bridges, and for reference, an outline thereof will be explained with reference to FIGS. 10 and 11. That is, as shown in FIG. 10, the hauling rope 56 is provided so as to be driven by power and run under its own power, and a rope carrier 57 is fixed to the hauling rope 56 and moves together with the rope 56. In the figures, the same reference numerals as those shown in FIG. 1 indicate the same members. As shown in FIG. 11, the rope carrier 57 has two carrier frames 59 and 60 supported by a frame boss 58 in a substantially L shape.
A hauling rope 56 is inserted and supported between the sleeves 62 of each holder 61, and each sleeve 62 is fixed by a rope at both ends of the sleeve 62 as shown in FIG. Stators 63, 6 are attached to 56 by means of alloy crimping means.
3 are crimped and integrated, and the terminal socket 14 of the catwalk rope 4 is secured to the connecting portion 64 of the frame boss 58, thereby transporting the catwalk rope 4, i.e. They carry out the handover. 65 haha rope 5
No. 6 guide roller is shown.

(Effects of the Invention) According to the temporary tensioning method of the present invention, the conventional temporary clamping method 16 using bolt tightening means and wedge means is abolished, and at the clamping position, the stopper 50 and the stopper 50 are locked by the alloy crimping means. By providing a joint fitting 51 that is connected to the temporary pulling rope 19 and performing the temporary pulling, it is possible to eliminate the lack of clamping force due to a decrease in clamping efficiency and the occurrence of clamp slippage as in the past, By fully integrating the stopper 50 with the rope 4 and utilizing the resulting large slip resistance, the stopper 50
By making the joint fitting 51 smaller, lighter, and requiring a simpler structure, it is possible to improve its handling, work efficiency, and work safety.
This shortens the construction period and reduces construction costs. In other words, by reducing the shape, dimensions, and weight of the temporary tension clamp structure, handling performance, work safety, and labor savings are achieved, and rope slippage during temporary tension is eliminated by making the clamp more reliable and strong. Moreover, the production and installation of this stopper can be easily added to the rope production process, and the production cost is also low. The reliability of the sliding strength of the stopper using such a crimped alloy method is fully guaranteed by experiments and past results, and it is extremely advantageous as a solution to the problems with temporary clamps in the temporary tension method of long suspension bridges. be.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional temporary tensioning method, Figures 2 and 3 are front and side views showing a conventional temporary tensioning clamp structure, and Fig. 4 is an explanatory diagram of an embodiment of the temporary tensioning method according to the present invention. Fig. 5 is an explanatory diagram of an example of mounting the stopper using alloy crimping means, Fig. 6 is an explanatory diagram of the hauling rope and rope carrier, Fig. 7 is an overall explanatory diagram of the cat walk, and Fig. 8 is an illustration of the same cat. Figure 9 is a front, plan, and side view of the walk floor assembly structure. Figure 9 is a plane and side view of the walk rope anchorage girder. Figure 10 is an explanatory diagram of an example of an erection state using hauling rope. Figure 11 is an illustration of the rope carrier. FIG. 3 is a front and side view. 1... Catwalk, 2... Main tower, 3...
Anchor part, 4... Cat walk rope, 7
... Floor assembly, 14 ... Terminal socket, 15 ... Cat walk rope fixing girder, 16, 16
a, 16b...temporary tension clamp, 18...temporary tension device, 19...temporary tension rope, 50...stopper, 5
1...Joint fitting, 56...Hole rope, 57...Rope carrier.

Claims (1)

[Claims] 1. In order to install a cat walk (work scaffolding) in a span during construction of a long suspension bridge, before stretching a cat walk rope across the span and attaching the terminal socket of the rope to the cat walk rope fixing girder, When the rope is temporarily pulled by the temporary pulling device installed on the top side of the tower, the rope is preliminarily placed at a predetermined position on the end side having the terminal socket of the above-mentioned cat walk rope using an alloy crimping means during rope manufacture. A stopper crimped and fixed is stretched, and a temporary pulling rope in a temporary pulling device is latched to the stopper at the site and connected to a joint fitting attached to the cat walk rope, and the temporary pulling rope is used to tighten the cat walk rope. 1. A temporary tensioning method for a cat walk rope, characterized in that the rope portion from the stopper to the terminal socket is freed through temporary tensioning, and the terminal socket is attached to the fixing girder.