JPS5998909A - Construction of tension material - 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] Industrial Field of Application This invention relates to the construction of tension members such as stay members in cable-stayed bridges, radio towers, etc. by tensioning a plurality of steel wires within a sheath. It is related to construction methods.

Prior art As shown in Fig. 1, a plurality of diagonal beams, which are tendons, are erected between the tower T and the deck 0, which are built on the ground.
Cable-stayed bridges that suspend The tension material used is one in which multiple pieces of steel wire, etc. are pushed through a protective sheath made of synthetic resin, etc., and the tension material is integrated by inserting steel wires, etc. into the sheath in advance. It was erected using a construction method in which the tower was lifted onto scaffolding erected on site and directly connected at both ends to Tower T and Deck D, respectively. Almost the same construction method is also used to erect tendons for other wireless towers, etc.

Such conventional tendon construction methods have the following problems.

■ The unit length of a tendon made by inserting multiple steel wires etc. into the sheath.In addition, the weight is extremely large and the diameter is also large.Also, in long cable-stayed bridges, etc., the length of the longest tendon is The length reached several hundred meters, and the task of lifting this tension material onto the scaffolding and connecting it between Tower T and Deck 0 was extremely difficult.

@ For long cable-stayed bridges, the scaffolding used to hang and pass tendons becomes extremely large.
Just building this scaffolding required time and labor costs.

θ Hard and thick synthetic resin tubes are used as sheaths, but tension materials with steel wires, etc. inserted inside these sheaths are manufactured in factories and wound around reels or other winding frames. When transporting the tension material to the site, it must be handled as a heavy object, and the framework such as the reel becomes large, making transport work extremely difficult, and sometimes transporting the tension material becomes impossible.

As mentioned above, if it is impossible to transport the tendons, it becomes necessary to construct a factory on site and assemble the tendons on site.

■ In a factory or on site, it is extremely difficult to insert and tension multiple steel wires into the sheath without tangling them, and the length of each tendon must be adjusted according to the installation location. High calculation accuracy is required.

In order to improve these drawbacks, the patent application No. 57-2090 was filed.
The tendon construction method disclosed by the applicant in No. 00 involves passing a sheath with anchor heads with index holes at both ends attached to the frame, and then inserting a steel wire or the like between the corresponding index holes of the anchor heads. The tension member is constructed by tensioning a steel wire or the like within the sheath.

According to this construction method, the steel wires are pushed through after the sheath is passed over the frame, making it easy to erect the tendons.

It eliminates the need to build huge scaffolding, eliminates the need to construct a factory on site, and facilitates the insertion of steel wires, eliminating all of the above drawbacks.

However, when the end of the sheath is located at a high location, it is extremely difficult to feed the steel wire close to the anchor head attached to the sheath end. In other words, in cable-stayed bridges, etc., it is necessary to build scaffolding on towers and lift steel wires etc. wound onto reels to high places, which is extremely troublesome and requires work at high places. presents a danger.

Purpose of the Invention This invention was made to improve the above-mentioned drawbacks, and when the steel wire, etc. is inserted into the sheath passed through the frame, it is extremely easy to feed out the steel wire, etc., thereby reducing the danger. The purpose of the present invention is to provide a tendon construction method that can be used to construct a tensile material.

Structure of the Invention The tendon construction method according to the present invention, when a steel wire or the like is inserted into a sheath having several anchor heads at both ends, installs a guide pipe with one end close to one of the anchor heads, The above object is achieved by feeding the steel wire etc. into the guide pipe from the other end and inserting the steel wire etc. into the sheath through the index hole of the anchor head.

EXAMPLE The present invention will be described in detail below based on an example of a cable-stayed bridge shown in the drawings.

CI) As the sheath connecting sheath 1, a cylindrical member made of a synthetic resin with good weather resistance is used to prevent rust, such as steel wire, but other materials such as stainless steel pipes can be used. Since it is extremely difficult to transport a long sheath 1, a plurality of sheaths 1 having a certain length are connected together and used for construction.

That is, an electric heating plate is interposed between adjacent sheaths 1, 1 to heat both end surfaces of sheaths 1, 1, and after heating, both end surfaces are pressed together and welded and connected.

A spiral spacer wire 11 is attached to the inner peripheral surface of the sheath 1.

It is also possible to attach a spacer wire 11 to the inner peripheral surface of the sheath 1 over the entire length after the sheath 1 is connected. Further, when a stainless steel pipe is used as the sheath 1, it is possible to connect them by welding.

[■] Formation of fixing holes in towers and decks Fixing holes 2.2 are formed through the tower T and deck D in correspondence with each other. The fixing holes 2.2 are formed at appropriate intervals in the vertical direction of the tower T and in the longitudinal direction of the deck D by the number of diagonal beams to be installed. The fixing holes 2, 2 formed in correspondence with the tower T and the deck D are bored so that the extension lines of the respective center lines are in a straight line.

The surfaces of the tower T and the deck D opposite to the side on which the diagonal members are installed are formed to intersect the center line of the fixing holes 2, 2 at right angles. A steel pipe 21.21 having seven zigzags at its end is buried in the fixing holes 2,2. There is a cylindrical socket (2) on the opposite side of each fixing hole 2, 2 from the side where the diagonal beam is installed.
2.22 are installed respectively. In particular, the socket 22 attached to the fixing hole 2 of the deck D has an adjusting nut 23 screwed onto its outer periphery, making it possible to adjust the position of the socket 22 in the direction of the center line of the fixing hole 2.

Anchor heads 3, 3 are fixed to the opposite side of the socket 22, 22 from the side on which the diagonal beam is installed. The anchor head 3.3 is on a disc as shown in Figure 6,
Index holes a1, a2, a3, .

Each index hole a1...aα is formed separately from each other, and the upper end anchor head 3 attached to the tower T side and the lower end anchor head 3 attached to the deck D are each index hole a1...aα. are positioned in correspondence with each other so that a straight line parallel to the center line of the fixing holes 2, 2 can pass therethrough.

A short sheath x1.11 is connected to each side of the diagonal beam (socket) 22.22 on which the diagonal beam is constructed.
21, and one end of the sheath 1', 1' projects toward the side where the diagonal beam is installed. Seven lunges are formed on the outer periphery of the lower end of the sheath 1' attached to the tower T side, and a cylindrical sealing material 24 having a flange is fitted to the outer periphery of the sheath 1' attached to the deck D side. The gap between the steel pipe and the pipe 21 is sealed.

(III) Sheath Installation The sheath 1 connected as described above is passed between the tower T and the deck 0 via a rack. One end of the sheath 1 is lifted up by a crane erected adjacent to the tower T and pulled to the vicinity of the fixing hole 2 of the tower T, and is positioned near the end of the sheath 1'. One end of this sheath l is fixed above the tower T, and the other end of the sheath l is attached to a steel annular beltcoat 6.
Hang it through something like.

The other end of the sheath 1 is drawn near the fixing hole 2 corresponding to the fixing hole 2 of the tower T of the deck D by an input or the like, and is positioned near the end of the sheath l'.

The end of this sheath 1' on the deck D side is also temporarily attached to the other end of a rope, one end of which is fixed to the deck D, via a belt or the like.

A sheath outer tube 14 is attached to the outer periphery of the end of the sheath L on the side of the deck D.
When the sheath L end and the sheath 1' end are connected as described later, the sheath outer tube 14 is fitted around the outer periphery of both ends to connect them. Sheath outer tube 14
The sheath 1 is fixed by heating both ends of the sheath outer tube 140.
This is done by welding to 1'.

(IV) Delivery of steel wire (Fig. 7) Sheath 1 installed between tower T and deck 0 as described above
A steel wire 4 or a steel weave wire or the like for holding the tension of the diagonal beam is fed with the required amount of wood vinegar. In the embodiment, a steel wire 4 is used, a reel 41 wound with this steel wire 4 is placed on a deck 0, etc., and the steel wire 4 is continuously fed from the reel 41 without being cut to the required length. put out.

The steel wire 4 is rotated by rollers 42 facing each other by a prime mover.
It is force-fed by a pusher 43 having a cylindrical shape, and is raised inside a hard guide pipe 44 such as a steel pipe that extends above the tower T along with the tower T. A bendable flexible guide pipe 45 made of synthetic resin or the like is provided at the upper end of the guide pipe 44.
are connected, and the tip of the flexible guide pipe 45 is positioned near the anchor head 3 attached to the fixing hole 2 of the tower T. Flexible guide pipe 45
are bendable, and the steel wire 4 can be fed into each index hole a1, . . . aα of the anchor head 3 without any problem.

Reel 41. The number of the bushings 43 and the guide pipes 44 is not limited to one each, but it is also possible to prepare a plurality of each and feed them sequentially to different index holes al...aα.

(V) Inserting the steel wire into the sheath The steel wire 4 fed from the reel 41 is inserted into the sheaths 1' and 1. Steel i! ! 4 is the tower of sheath 1 as mentioned above.
= Since it is raised to the vicinity of the fixing hole 2 on the T side, it is inserted through the index holes a1...aα of the upper end anchor head 3 and lowered into the sheath 1.

The six index holes a1, . In the embodiment, index holes a1 and 1 as shown in FIG.
. . . are inserted from the hole a1 located at the top of aα, and the holes a2 . . . a3... and finally into the index hole aα located at the bottom.

In addition, the steel wire 4 is inserted in order from the index hole a1 located at the top, then inserted into the index hole aα located at the bottom, and then the upper index hole aα-
Insert into β and finally the hole aα-C in index plate 3
In short, any order can be selected as long as the steel wires 4 in the sheath 1 are not entangled with each other.

The tension of the steel wire 4 will be described later, but the steel wire 4 inserted into the index hole a1 of the upper end anchor head 3 descends along the bottom of the inner circumferential surface of the sheath 1 and reaches the lower end anchor head 3.
If the steel wire 4 is inserted into the corresponding index hole a1 and tensioned, the entire length of the steel wire 4 will be located at the top of the sheath 1, which will hinder the subsequent steel wire 4 from descending along the bottom of the inner peripheral surface of the sheath 1. There is no possibility that the steel wire 4 that has already been placed under tension and the following steel wire 4 will become entangled.

After the steel wire 4 that has been inserted first is tensed as described above, the steel wire 4 is lowered in order and inserted into the sheath 1.

After the steel wires 4 are inserted into all the index holes a1, .

Effects of the Invention The tendon construction method according to the present invention has the above-mentioned configuration, and the steel wire, etc. is sent out using a guide pipe to reach near the anchor head, and the steel wire, etc. is sequentially inserted into each index hole. Since the steel wire is inserted through the wire, there is no need to set up a large-scale work scaffold, and it is extremely easy to feed out the steel wire, etc., and the dangers during work can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a front view of an embodiment of a cable-stayed bridge, Fig. 2 is an explanatory view of the state in which tension members are passed across the tower and deck, Fig. 3 is a longitudinal cross-sectional view of the fixing holes formed in the tower, Fig. 4 is a vertical cross-sectional view of the fixed hole formed in the deck, Fig. 5 is a cross-sectional view of the tendon, Fig. 6 is a plan view of the anchor head, and Fig. 7 is an explanatory diagram of the feeding state of the steel wire. It is. T...I'')-D...Deck, L...Dialine, 1...Sheath, 2...Fixing hole, 3...Anchor head, 4...Steel wire, 5...Pilot cap, 6... Cart, 8... Lead cap, 9... Index spacer, 11... Spacer wire, 44... Guide pipe. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A sheath with anchor heads each having an index hole attached to each end is passed over the rack, and then a steel wire or the like is inserted between the corresponding index holes of the anchor head, and the steel wire is inserted into the sheath. In a tendon construction method in which a tendon is erected by tensioning a wire, etc., a guide vibe is installed with one end close to one of the anchor heads, and the steel wire, etc. is fed into the guide pipe from the other end, and the steel wire, etc. is fed into the guide pipe from the other end. A tendon construction method characterized in that the steel wire or the like is inserted into the sheath through an index hole of an anchor head.