JPS5998974A - 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 Application Field This invention relates to a tension member construction method for constructing tension members such as diagonal members by tensioning a plurality of steel wires inside a sheath in cable-stayed bridges, radio towers, etc. It is related to.

Prior art As shown in Fig. 1, a plurality of diagonal beams, which are tendons, are erected between the tower T and the deck 9, which are built on the ground.
Cable-stayed bridges that suspend As the tension material, steel wire or multiple stranded steel wires are inserted into a protective sheath made of synthetic resin or the like. It was erected using a construction method in which it was lifted onto scaffolding erected on the ground, and directly connected both ends to Tower T and Deck D, respectively. Almost the same method was used to erect tendons for other radio towers, etc.

Such conventional tendon construction methods have the following problems.

■ The weight per unit length of a tension member with multiple steel wires etc. inserted into the sheath becomes extremely large, and the diameter also becomes thick, and in long cable-stayed bridges, the length of the longest tension member is several times The length reached 100 meters, and the work of lifting this tension material onto the scaffolding and connecting it between Tower T and Deck 9 was extremely difficult.

◎ For long cable-stayed bridges, etc., the work scaffolding becomes extremely large, and it takes time and money just to assemble the scaffolding.

Hard and thick synthetic resin tubes are used as O-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 tension materials to the site, they must be handled as heavy objects, and as the frame diameter of reels and other equipment increases, the material to be transported becomes bulky, making transport work extremely difficult and sometimes impossible. Sometimes it happened.

■ As mentioned above, if it is impossible to transport the tendons, it will be 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 N-sheath without tangling them, and the length of the tension material must be adjusted according to the installation location. must be set, and high measuring accuracy is required.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a tendon construction method as described below.

■Tension material erection method that makes it extremely easy to erect tension materials.

■ Tension material construction method that does not require huge scaffolding.

Ω A tension material erection method that is easy to transport and does not require the construction of a factory on site when assembling the tension materials.

@ Tensile construction method that makes it easy to insert and tension steel wires into the sheath.

Structure of the Invention The tendon construction method according to the present invention involves installing an anchor head having index holes at both ends, passing the sheath over the frame, and then inserting a steel wire or the like between the corresponding index holes of the reading anchor head. The above purpose is achieved by erecting tension members by tensioning steel wires or the like within the structure.

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

[I] 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 a steel wire, but other materials such as stainless steel pipes can also be used. It is extremely difficult to transport a long sheath 1, so a plurality of sheaths 1 having a certain length are connected together and used for construction.

As shown in FIGS. 7 to 9, a spacer wire 11 is spirally attached within the sheath 1 so as to be in contact with the inner peripheral surface thereof. The spacer wire 11 is a member such as a galvanized steel wire wound into a coil, and the diameter of the spacer wire 11 is set larger than the inner diameter of the sheath 1. A conical insertion tube 12 is connected to one end of the sheath 1, and a spacer wire 11 is placed on the insertion tube 12.
Hook the lead wire 13 on the tip of the spacer wire 1
1 into the sheath 1. The spacer wire 11 is elongated in the longitudinal direction, its diameter is reduced, and the spacer wire 11 is attached to the inner circumferential surface of the sheath 1 in a spiral manner. The spacer wire 11 is cut at both ends of the sheath 1. Both ends can also be fixed to the inner circumferential surface of the sheath 1 by a U-shaped fixing pin or by welding with synthetic resin.

A plurality of sheaths 1 configured as described above are connected. 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.

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. If a stainless steel pipe is used as the rounded sheath 1, it is possible to connect them by welding.

(Il) Formation of fixing holes in tower and deck Tower T
Fixing holes 2, 2 are formed penetrating through the deck D, respectively, 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 members to be constructed. 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 a flange at its end is buried in the fixing holes 2,2. There is a cylindrical socket on the opposite side of each fixing hole 2, 2 from the side where the diagonal beam is installed) 2
2. :22 are installed respectively. In particular, the socket 22 attached to the fixing hole 2 of the deck D has an adjustment nut 26 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 and 6 are fixed to the sides of the anchors 1-22 and 22 opposite to the side on which the diagonal beams are installed. The anchor head 3.3 is disk-shaped as shown in FIG. 6, and has index holes a1. a2゜a5...aα is perforated. 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 6 attached to the deck D are each index hole a1...- aα are positioned so that a straight line parallel to the center line of the fixing holes 2, 2 can pass therethrough.

A short sheath 1'+1' is connected to the side where the diagonal member L of the socket 1-22.22 is installed, and each steel pipe 21
．． 21, and one end of the side sheath 11.11 on which the diagonals are built is made to protrude. A flange is formed on the outer periphery of the lower end of the sheath 11 attached to the tower T side, and a cylindrical sealing material 24 having a flange is fitted to the outer periphery of the sheath 11 attached to the deck D side, and the steel pipe 21 The gap between the two is sealed.

(I [I) Sheath Installation - The sheath 1 connected as described above is passed between the tower T and the deck 9 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 11. One end of this sheath 1 is suspended from the other end of a rope 25 whose one end is fixed above the tower T via a steel annular belt 26 or the like.

The other end of the sheath 1 is manually drawn to the vicinity of the fixing hole 2 corresponding to the fixing hole 2 of the tower T of the deck D, and positioned near the end of the sheath 11. The end of this sheath 11 on the deck D side is also temporarily attached to the other end of a rope whose one end 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 1 on the deck D side.
As will be described later, when the sheath 1 end and the sheath 1' end are connected, the sheath outer tube 14 is fitted around the outer periphery of both ends to connect them. The sheath outer tube 14 is fixed by heating both ends of the sheath outer tube 14.
This is done by welding to 1.

[■] Steel wire delivery Sheath 1 installed between tower T and deck 9 as described above
A required number of steel wires 4 or steel stranded wires, etc., for receiving the tension of the diagonal members are fed out.

In the embodiment, a steel wire 4 is used, and a reel 41 wound with this steel wire 4 is placed on a deck 9 or the like, and the steel wire 4 is removed from the reel 41.
Continuously send out without cutting it to the required length.

The steel wire 4 is rotated by rollers 42 facing each other by a prime mover.
It is force-fed by a pusher 46 having a cylindrical shape, and is raised inside a hard guide pipe 44 such as a steel pipe that extends along the tower T and above 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 to each other, and the tip of the flexible guide pipe 45 is positioned near the anchor head 6 attached to the fixing hole 2 of the tower T. Flexible guide pipe 45
is bendable, and the steel wire 4 can be fed out to each index hole a1, . . . aα of the anchor head B without any trouble.

The reel 41, the pusher 43, and the guide pipe 44 are not limited to one each, but it is also possible to prepare a plurality of each and feed them sequentially to different index holes a1, . . . aα.

[v] Inserting the steel wire into the sheath The steel wire 4 fed out from the reel 41 is inserted into the sheath 11,1. As mentioned above, the steel wire 4 is raised to the vicinity of the fixing hole 2 on the tower T side of the sheath 1, so it is inserted through the index hole a1...aα of the upper end anchor head 6 and lowered into the sheath 1. Insert it as you push it.

Although the index holes a1...--aα are inserted in order, various modes can be considered for the order of insertion. In the embodiment, an index hole a1 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 through β and finally the hole aα-ε in index plate 6.
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 B descends along the bottom of the inner surface of the sheath 1 and enters the corresponding index hole a1 of the lower end anchor head B. If the steel wire 4 is inserted and tensioned, the entire length of the steel wire 4 will be positioned at the top of the sheath 1, and the subsequent steel wire 4 will not be a hindrance to descending along the bottom of the inner peripheral surface of the sheath 1. There is no possibility that the steel wire 4 installed under tension and the following steel wire 4 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.

Since it is difficult to insert the steel wire inside the sheath 11 into the index holes a1...aα of the anchor head B at the lower end of the sheath 11 on the deck D side, the tip of the wire rope 81 as shown in FIG. A member with a sheath-like lead cap 8 attached thereto can be used. That is, wire rope 81
Index hole a1...aα of deck plate B
is inserted into the sheath 11 and positioned in advance. The lead cap 8 projects above the sheath 11,
The other end of the wire rope 81 is made to protrude below the lower end anchor head 6.

Fitting the tip of the steel wire 4 into the lead cap 8, feeding out the steel wire 4 again, and pulling the wire rope 81 downward,
The steel wire 4 is securely inserted into the index hole a of each anchor head 6.
1...Insert it into aα.

[■] Attaching the pilot cap enables smooth sliding of the steel wire 4 within the sheath 1 when the steel wire 4 is lowered into the sheath 1, and also allows the steel wire 4 to slide smoothly into the sheath 1.
A pilot cap 5 is attached to the tip of the steel wire 4 to eliminate entanglement.

As shown in FIG. 13, the pilot cap 5 is cylindrical and has a truncated conical shape parallel to the cap body 51, which is tapered so that the inner peripheral surface at one end gradually becomes smaller as it approaches the tip. A wedge 52 having a locking hole 5 having a circular cross section is inserted through the 2,000-sided surface. The inner diameter of the locking hole 56 of the wedge 52 is smaller than the outer diameter of the steel wire 4 to be attached, and the wedge 52 is cut parallel to the locking hole 56 and divided into a plurality of pieces. Cap body 5
A head 54 with a rounded tip is attached to the other end of the head 1 by a screw. A coil spring 55 is interposed between the head 54 and the wedge 52 in the cap body 51, and the wedge 52 is connected to the cap body 51.
It is constantly pressed against the tapered inner circumferential surface of. The outer diameter m of the cap body 51 is set larger than the intervals S between the steel wires 4 passing through the index holes a1, . . . aα of the anchor head 6.

The pilot cap 5 configured as described above is connected to the steel wire 4.
We will explain the work to attach it to the tip.

The steel wire 4 is inserted from the opening side of the cap body 51 of the pilot cap 5, and is also inserted through the locking hole 56 G9 of the wedge 52. Although the inner diameter of the locking hole 53 is smaller than the outer diameter of the steel wire 4, the wedge 52 is pushed back to the opposite side by the tip of the steel wire 4 against the elastic force of the coil spring 55, so that the inner diameter of the locking hole 56 becomes larger. This becomes possible and is pushed outward by the penetration of the steel wire 4. If you insert the steel wire 4 for a certain length and release it, the steel wire 4
Although the wedge 52 tries to return to its original state due to the elastic force of the coil spring 55, the outer circumferential surface of the wedge 52 slides against the tapered inner circumferential surface of the cap body 51 and the locking hole 56
The inner diameter is reduced to clamp the steel wire 4. Therefore, even if the steel wire 4 is pushed into the pilot cap 5, it will not be pulled out by the head 54, and even if an attempt is made to pull it out, it will be impossible to pull it out because it is held between the wedges 52. To remove the pilot cap 5, use the head 54.
It would be a good idea to release the elastic force of the coil spring 55 acting on the wedge 52 by removing it.

The pilot cap 5 is attached to the tip of the steel wire 4 after the steel wire 4 has passed through the upper end anchor head 3, the sheath 1', and the index spacer 9. In the embodiment, as shown in FIG. 12, an index spacer 9 having a flange on the outer periphery is interposed between the sheath 1' and the sheath 1, and the index spacer 9 is passed through the index holes a1...aα of the index spacer 9. Attach the pilot cap 5 in the manner described later.

The steel wire to which the pilot cap 5 is attached slides smoothly inside the sheath 1 because the tip of the head 54 is rounded.

Also, the outer diameter m of the camp body 51 of the pilot cap 5 is the index hole a1...aα of the anchor head 6.
The steel wires 4 already stretched in the sheath 1 are set larger than the intervals S between the steel wires 4 inserted through the holes in the sheath 1.
, 4, the pilot cap 5 does not enter into the gap between them. Therefore, the pilot cap 5 will not guide the steel wire 4 to an unplanned position, and the steel wire 4 will not become entangled with other steel wires 4.

The pilot cap 5 is removed from the steel wire 4 using the sheath 1.
This is in the gap that exists between the lower end of the sheath 11 and the end of the sheath 11 on the deck D side. At this gap, remove the pilot camp 5 as described above, and insert the steel wire 4 into the sheath 1.
1, insert it into the index hole a1...aα of the lower end anchor head 6, and insert the tip into the index hole a1...aα of the lower end anchor head 6.
Make it protrude downward.

[■] Tension of steel wire The steel wire 4 inserted into the sheath 1 is tensioned as described above.

A hydraulic jack or the like is used to tension the steel wire 4, and the end of the steel wire 4 is grasped and tensioned.

The taut steel wire 4 is fastened by wedges, compression grips, etc. on opposite sides of the upper and lower end anchor heads 6.6, which are anchor plates. In the embodiment, a wedge 61 is provided on the lower end anchor head 6 side.
It is fastened by a compression grip 62 on the upper end anchor head 3 side.

As shown in FIG. 10, a cylindrical steel pipe or the like is used as the compression grip 32, and the compression grip 32 is passed through a die and crushed to grip the steel wire 4. The steel wire 4 is not cut near the end of the compression grip 62 on the opposite side of the compression grip 62 from the anchor head 6,
Cut the steel wire 4 to the required length. By gripping the ends of the steel wires 4 and pulling them using a hydraulic jack or the like, it is possible to easily check whether the steel wires 4 are intertwined with other steel wires 4 or not. In other words, when a steel wire 4 is entangled with another steel wire 4, considerable frictional force is generated, so if one end is pulled with a constant force by a hydraulic jack, the other end will not be pulled with the same force. , it can be confirmed that the steel wires 4 are intertwined with each other. On the other hand, when the steel wire 4 is not entangled with other steel wires 4, the pulling force at one end and the pulling force are approximately the same, and it can be confirmed that there is no entanglement.

By interposing and fixing a shim between the compression grip 62 and the anchor head 3, the tension on the steel a4 can be easily released. In addition, it is easy to attach a coupler to the steel wire 4, and it becomes possible to pour concrete into a PC structure.

(IX) After the steel wires 4 are inserted into the sheath 1 one by one and tensioned to a degree greater than or equal to the tension of all the steel wires, all the steel wires 4 are tensioned at the same time.

Since considerable force is required to tension the entire steel wire 4, the 14th
As shown in the figure, a high-output hydraulic jack 61 is used.

The hydraulic jack 61 is heavy and has to be transported manually.
Since it is impossible to set the inclination angle and height according to the work situation, it is placed on a trolley 6. The truck 6 has an elevating section 64 mounted on a movable traveling section 66 having wheels 62 via a parallel link mechanism. As a parallel link mechanism, two links 65.65 are connected by pins at their midpoints, one of the links 65.65 on either the left or right side is pinned to the running part 66, and the other is connected to the elevating part 64. is pinned to. A pin is secured to the opposite end of the link 65, 65 so as to be slidable in a long hole 66, 66 formed horizontally in the running part 66 and the elevating part 64, respectively. By expanding and contracting the hydraulic jack 67 to pin the link 65, the intersecting angle of the links 65 and 65 changes, and the elevating section 64 vertically moves up and down.

On the elevating section 64, one end of a guide rail 68 is pin-fixed to the elevating section 64, and the other end is pin-fixed to the rond tip of a hydraulic jack 69, which is pin-fixed to the other end of the elevating section 64. Inside the guide rail 68, there is a rod-shaped screw 7 extending approximately the entire length.
1 is built-in, and this screw 71 can be rotated by a motor or the like. A nut 72 is fixed to the side of the high-output hydraulic jack 61, and a male thread on the outer periphery of the screw 71 is screwed into a female thread on the inner surface of the nut 72.

To move the high-output hydraulic jack 61 in the vertical direction, the lifting section 64 is raised and lowered by the parallel link mechanism described above.
The inclination angle of the high-output hydraulic jack 61 is adjusted by changing the angle of the guide rail 68 by expanding and contracting the rond of the hydraulic jack 69. The position of the high-output hydraulic jack 61 in the inclination direction can be adjusted by rotating the screw 71 and moving the nut 71 screwed onto the screw 71 along the guide rail 68.
This is done by moving a high-output hydraulic jack 61 that is integrated with 1.

By using the high-output hydraulic jack 61 placed on the trolley 6 configured as described above, it is possible to always tension the entire steel wire 4 at a suitable position and height.

By the final tensioning operation of the steel wire 4, the deflection of the steel wire 4 is completely eliminated, and at the same time, the deflection of the sheath 1 is also eliminated, and the final connection operation of the sheaths 1 and 11 is performed.

[X] Grout injection In order to prevent rust of the steel wire 4, grout is injected into the sheaths 1 and 11. As grout, mortar synthetic resin etc. can be considered, but since the grout is injected from below the sheaths 1 and 11, lightweight synthetic resin is easy to pump and does not cause cracks after hardening, so it is extremely suitable as grout. .

Grout is injected from the side of the grout injection tube by interposing a cylindrical grout injection tube between the opposing ends of the sheath 11 and the sheath 1 on the deck D side and fitting into both ends. It is also possible to inject from below the sheath 11.

CXD Intermediate index spacer The tendon construction method according to the present invention completes the erection of tendons such as diagonal beams by the above-mentioned work order.
In addition, in order to completely prevent entanglement of the wires 4 and to confirm accurate tensioning of the steel wires 4, it is conceivable to install one or more intermediate index spacers 91 in the middle part of the sheath 1.

The intermediate index spacer 91 has index holes a1...a as well as the upper and lower end anchor heads 6.3.
α is formed, and a collar is formed on the outer periphery. The intermediate portion of the sheath 1 is cut at an appropriate position, and a flange is formed on the outer periphery of the cut end of the sheath 1. The intermediate index spacer 9I is positioned between the cut ends of the sheath 1, the flanges of the index spacer 9+ are held from both sides by flanges, and the two are fastened and connected using bolts and nuts.

If the index holes a1...aα of the intermediate index spacer 91 installed in this way correspond to the index holes a1...aα of the upper and lower end anchor heads 3, 6, and the steel wires 4 are inserted through them. Also in the intermediate portion of the sheath 1, the steel wires 4 are supported by the index holes a1, . Further, in order to confirm that the steel wire 4 is correctly stretched, the flanges of the sheath 1 that are in contact with both sides of the intermediate index spacer 91 can be bolted.

Effects of the Invention Since the tendon construction method according to the present invention has the above-described configuration, the following effects can be obtained.

■ For the tension material, first, only a lightweight sheath is passed between the tower and the deck, and then steel wires, etc. are sent out one by one and inserted into the sheath, so each task is no longer extremely difficult, such as lifting heavy objects. The work becomes extremely easy.

■ Since the tension members are lifted and erected using cranes, there is no need to erect huge scaffolding, which reduces construction costs and construction days.

■ As for tension materials, each member such as sheath and steel wire can be carried separately to the site.1. Not only does transportation work become extremely easy,
There is no need to construct a factory for assembling tendons on site.

@ Since the steel wires are fed into the sheath one after another, it is easy to tension the steel wires, and since the sheath is equipped with an anchor head with an index hole, each steel wire can be inserted into the sheath without getting entangled with each other. Can be stretched.

[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 a state in which tension members are passed across the tower and deck, Fig. 6 is a longitudinal cross-sectional view of anchor holes formed in the tower, Figure 4 is a longitudinal cross-sectional view of the fixing hole formed in the deck, Figure 5 is a cross-sectional view of the tendon, Figure 6 is a plan view of the anchor head, and Figure 7 is a longitudinal cross-section of the spacer wire inserted into the sheath. 8 and 9 are longitudinal cross-sectional views of the sheaths in a connected state, Fig. 10 is a side view of the compression grip fixed to the steel wire, and Fig. 11 is a longitudinal cross-sectional view of the intermediate index spacer installed. Fig. 12 is a vertical cross-sectional view of the steel wire being sent out, Fig. 16 is a longitudinal cross-sectional view of the pilot camp, Fig. 14 is a side view of the high-output hydraulic jacking cart, and Fig. 15 is a vertical cross-sectional view of the steel wire being fed out. FIG. 3 is a longitudinal cross-sectional view of the steel wire inserted into the sheath. T... Tower, D... Deck, L... Diagonal material, 1... Sheath, 2... Fixing hole, 6... Anchor head, 4... Steel wire, 5... Pilot-1-Yap, 6...・Dolly, 8...
Lead cap, 9... Index spacer, 11...
・Spacer wire, 44... Guide pipe, 61... High output hydraulic jack. Figure 2 Figure 3 Figure 4 Figure 5v and Figure 6 1 Figure 14 Figure 15 Procedural amendment, Kayo, 1. Indication of the case 1982 Patent Application No. 209000 2. Name of the invention Tension material Erection construction method 3, relationship with the case of the person making the amendment Patent applicant residence analysis Yama 1) Kunimitsu 06 Tokyo Rope Co., Ltd. 4, agent 5, daily publication of amendment order Self-initiated amendment

Claims (1)

[Claims] A sheath with anchor heads with index holes attached to both ends is passed over the frame, and then a steel wire, etc. is inserted between the corresponding index holes of the reading anchor head, and the steel wire, etc. is tensioned within the sheath. Tensile material construction method for erecting tension materials.