JPS61106808A - Costruction of cable - 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 an improvement in a cable installation method.

(Prior art) Conventionally, when installing cables for suspended structures such as cable-stayed bridges,
The following method is used to pull the cable to the anchoring point. In other words, attach a pull rod with a thread on the outer periphery to one end of the cable. ! , and with the other end of the cable fixed to the structure at the location where it should be installed, the pull rod was passed through the terminal bearing plate and the guide member, and tension was applied to the cable via the pull rod with jacks. After that, the terminal fitting is locked to the bearing plate. This method has the problem that a large amount of deflection occurs in the cable due to its own weight, so a large tension force is required to pass the pull rod through the guide member, and the pull rod also has to be long.

Therefore, as a means to reduce the force required to pull the pull rod to the guide member, as shown in FIG. The intermediate part is supported by a truck crane 14 to reduce the slack of the cape, /L/"""focal line"""1 state""°solid line """1 state"", thereby reducing the cable tension length p. Retraction amount Δ up to
The terminal fitting 20 is brought close to the girder 13 so that Ω is as small as possible. In addition, as shown in FIG. 11, when an erection member 15 is stretched above the cable 1 to support the middle part of the cable 1, or when the girder 13 is constructed by an overhanging method, the jacks 16 A method of reducing Δρ by raising the end of the girder 13 higher than a predetermined position has also been adopted. Sharpening by these methods is itself
Extra equipment and labor were required, and the pull rods were also quite long.

In the conventional method, 11! of the contact surface is used as a means for locking the strand as a temporary lead wire. Since a locking member using frictional resistance is used, there is a problem in that the retracting operation is not reliable. In other words, during cable installation,
It is inevitable that the surface of the strand will be scratched or rusted, which will significantly change the coefficient of friction of the contact surface between the strand and the locking member. ``5'''t'l[1HIk'''31'A
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.

Because of this, the crimping force of the locking member is not constant.
□Frictional resistance (locking force) will vary, which will cause the locking member to slip. This slip could cause the cable in the middle of installation to collide with other structures, creating a dangerous situation.
In order to prevent this, extremely time-consuming management was carried out.

(Objective of the Invention) This invention was made against this technical background, and it does not require any extra work as in the past, and the length of the pull rod can also be made significantly shorter than in the past. hand,
The present invention provides a method that can reliably prevent slips.

(Structure of the Invention) In the present invention, a pull rod having a thread on the outer periphery is screwed onto one end of the cable, and the pull rod is connected to the end of the cable while the other end of the cable is fixed to a structure at the installation position. In this method, the terminal tool is fixed to the bearing plate after penetrating the care pull through the bearing plate of the tool and the guide member and applying tension to the care pull via the pull rod using jacks. A temporary lead-in wire is connected, a locking member mechanically coupled to the wire is attached to the temporary lead-in wire, and the pull rod is inserted into the guide member through the locking member and the temporary lead-in wire by the jack. The cable is pulled in and then jacked to apply tension to the cable via a pull rod.

(Embodiment) FIG. 1 shows an apparatus used for carrying out the present invention, in which a pull rod 2 is connected to a terminal fitting 20 of a cable 1 via a coupler 17.
One end of the pull rod 2 is connected to the other end of the pull rod 2, and an anchor head 68 at one end of a wire for temporary drawing (medium diameter bolt) 6 is connected via a coupler 21, and the other end of the medium diameter bolt 6 is further connected to a temporary drawing wire (medium diameter bolt) 6. An anchor head 91 at one end of the wire rod (small diameter bolt) 9 is coupled via a coupler 69. The medium diameter bolt 6 is formed of a bolt thinner than the pull rod 2.

Bearing plate 3 that finally fixes the terminal tool 2o
A hole 30 is formed in the hole 30 through which the terminal fitting 20 passes, and a bolt hole 31 for connecting the guide member 4 is formed around the hole 30 .

The guide member 4 consists of a pair of side plates 41, an end plate 42, and two intermediate plates 43, each of which has a hole 40 through which the pull rod 2 passes. A bolt fitting part 45 is formed, and a bolt 47 is fitted into this bolt fitting part 45 and screwed into the bolt hole 31 to couple the guide member 4 to the bearing plate 3. Further, a jack 5 is connected to the end plate 42 of the guide member 4 by a bolt 46 passing through a bolt hole 44.

Between the end plate 42 and the intermediate plate 43 of the guide member 4 are a first nut 99 and a wire rod 6. which are screwed together with the pull rod 2. -9
Locking means 7 are arranged for this purpose.

This locking means 7 includes a support plate 72 having a hole 73 through which the small diameter bolt 9 and the medium diameter bolt 6 pass, a nut 74 screwed onto the small diameter bolt 9, and a medium diameter hole 61''.
a 't'L 6 t '''75'!''''' 6 a
As shown in FIG. 2, a nut 75 screwed onto a medium-diameter bolt 6 passing through a hole 73 is supported by a support plate 72. When the small diameter bolt 9 is passed through the hole 73, the nut 74 screwed therein is supported by the support plate 72 via the nut 75. Note that the reason why the plurality of holes are formed in the support plate 72 is to use them when a plurality of temporary lead-in wires are connected to the pull rod 2.

Further, instead of the temporary lead-in wire rod 6°9, a medium-diameter PC steel wire 60 and a small-diameter PC steel wire 90 may be used as temporary lead-in wires at the other end of the pull rod 2.
An anchor head 63 at one end of the 5i stranded wire 6o is coupled via a coupler 21, and a small diameter pcuA stranded wire 90 is coupled to the other end of the medium diameter PC steel stranded wire 60 via a coupler 69. Further, stoppers 61 are fixed to the medium-diameter PC steel stranded wire 60 at predetermined intervals, and stoppers 93 are fixed to the small-diameter PC steel stranded wire 90 at predetermined intervals. Then, as shown in FIG. 3, this temporary lead-in wire rod
It penetrates through the hole 73 of No. 2 and is supported by the support plate 72 via an annular washer 62 made of a pair of members.

A hole 50 through which the pull rod 2 passes is formed in the jack 5. A second nut 19 that is screwed onto the pull rod 2 and a locking means 8 are arranged on the end surface of the piston rod 51. 8 is a small diameter bolt 9 similar to the locking means 7.
and a support plate 8 having a hole 83 through which the medium-diameter bolt 6 passes.
2, a nut 84 screwed onto the small diameter bolt 9, and a nut 85 screwed onto the medium diameter bolt 6.

Next, a cable tensioning method using the above device will be explained. First, connect one end of the cable 1 to the tower 1 as shown in FIG.
At the other end of the cable 1, attach a member 33 to the bearing plate 3 and fix it at a predetermined position on the girder 13. is pulled to pass the small diameter hole 9 through the guide member 4 and jack 5.

When the cable 1 is pulled in as described above, it becomes slack due to its own weight (
Nag H) occurs, which causes bending deformation in the temporary lead-in wire. This deformation becomes greater as the retraction distance of the temporary lead-in wire rod becomes smaller (the radius of curvature R becomes smaller), that is, as the retraction m increases, the amount of deformation becomes smaller. In any case, bending stress continuously acts on the temporary drawing wire, and therefore, in order to smoothly draw the wire, a corresponding bending deformation must occur. For example, if the length of cable 1 is about 200 m, the radius of curvature R is 30 m.
It is necessary that a bending deformation of about 0.00 mm occurs.

Therefore, it is necessary to set the temporary lead-in wire to a thickness that will cause this degree of bending deformation, and for this reason, the temporary lead-in wire is set to be thinner than the pull rod 2 as described above.

As shown in FIG. 5, while the small diameter bolt 9 is held by the locking means 7.8, the jack 5 is driven to project the piston rod 51' into the state shown in FIG. 6, and from this state. While the locking means 7 is moved back to a position where it contacts the nut 99, the locking means 8 is brought into contact with the end surface of the piston rod 51 without recessing the piston rod 51. By repeating this operation, the small diameter bolt 9 is intermittently retracted by one stroke of the piston rod 51, and subsequently the medium diameter bolt 6 is retracted in the same manner. In this operation, the locking means is composed of a nut mechanically connected to the wire and a support plate that supports it, so unlike conventional locks that rely on frictional contact, problems such as slipping can occur. There is no sleet that occurs, and there is a certain f
il' movements can be performed.

When the tip of the pull rod 2 passes through the intermediate plate 43, a nut 99 is screwed onto the pull rod 2 as shown in FIG. One stroke per stroke.
Perform a pull-in operation. When the tip of the pull rod 2 protrudes by the jack 5, the coupler 21 is loosened, the medium diameter bolt 6 is removed, and the nut 19 is screwed onto the tip of the pull rod 2 as shown in FIG. Then, operate the jack 5, pull the pull rod 2 with the nuts 19 and 99, and
i9fgk, *tyoci*g20$ prescribed (7)
(Q10. After kneeing, insert the shim plate 35 from the side to support the terminal fitting 20 on the bearing plate 3, and then remove the guide member 4 and pull rod 2.

The above operation was explained for the case where the medium diameter bolt 6 and the small diameter bolt 9 were used as the temporary lead-in wire, but the medium diameter PC
The same applies to the case where the steel stranded wire 60 and the small diameter PC steel stranded wire 90 are used. Furthermore, instead of using the medium-diameter bolt 6 and the small-diameter bolt 9 connected in series, a plurality of small-diameter bolts 9 may be used in parallel. Of course, in this case as well, it is possible to cope with the bending deformation imparted to the temporary drawing wire during drawing.

(Effects of the Invention) As explained above, in the present invention, a temporary lead-in wire rod having a wire diameter smaller than that of the pull rod is connected to the end of the pull rod, and a locking member is mechanically connected to the wire rod. Install it as shown, Ji1! Tension is applied to the cable using a pull rod, and the temporary retraction until the pull rod is used can be performed using the same device as the pull rod, so there is no need for extra equipment or work such as temporary members. Cables can be easily installed.

Furthermore, since the cable terminal can be pulled in close to the bearing plate by using the temporary lead-in wire, the length of the pull rod can also be shortened.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing one example of a device for implementing the present invention, Fig. 2 is a perspective view of a locking means, Fig. 3 is a perspective view showing another example of the locking means, and Fig. 4 1 is an explanatory diagram of the cable installation process, FIGS. M5 to 9 are sectional views showing the pulling process, and FIGS. 10 and 11 are explanatory diagrams of the cable installation process to explain the conventional method. DESCRIPTION OF SYMBOLS 1... Cable, 2... Pull rod, 3... Bearing plate, 4... Guy 1ζ2 member, 5... Jacket, 7° 8... Locking means, 6, 9, 60.90・
・Wire for temporary lead-in. Patent applicant: Shinko Wire Industry Co., Ltd. No. 2
Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 10

Claims (1)

[Claims] 1. A pull rod having a thread on the outer periphery is screwed onto one terminal of the cable, and the pull rod is attached to the terminal with the other end of the cable fixed to the structure at the location where it is to be installed. In this method, the cable is passed through the bearing plate and the guide member, and tension is applied to the cable via the pull rod by a jack, and then the terminal fitting is locked to the bearing plate. Connecting a lead-in wire, attaching a locking member mechanically coupled to the wire to the temporary lead-in wire, and pulling the pull rod into the guide member using the jack via the locking member and the temporary lead-in wire; A cable installation method characterized in that a jack is then used to apply tension to the cable via a pull rod. 2. The method of constructing a cable according to claim 1, wherein a bolt is used as the wire rod and a nut is used as the locking member. 3. The method of constructing a cable according to claim 1, characterized in that the wire rod is a prestressed steel strand, and the locking member is a stopper fixed to the prestressed steel strand at a predetermined interval. 4. The cable according to claim 1, wherein a plurality of wires having different diameters are connected so as to become thinner from the pull rod side to the other side as the wire rod. construction method.