JPH07139094A - Anchor device for prestressed hollow pc steel rod - Google Patents

Abstract

PURPOSE:To hold pre-stress introduced to a hollow PC steel rod, using the rod as a reaction force bearing member by employing an anchor device having a simple construction and a small size. CONSTITUTION:A stopper 3 is detachably fixed to one end of a hollow PC steel rod 1 for catching one end of another PC steel rod 2 inserted therein, and an internal thread 6 formed on one end of a bearing cylinder 5 is screwed to an external thread formed on the external surface of the other end of the rod L1. An external thread formed on the external surface of an annular engagement piece 8 is screwed to the internal thread on the other end of the cylinder 5, thereby coupling a presser engagement piece 10 at an intermediate position in the cylinder 5 to the annular engagement piece 8. According to this construction, a compression force is applied to the PC steel rod 2 and tension pre-stress is introduced to the hollow PC steel rod 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for a hollow PC steel rod into which a prestress is introduced, which is used when prestressing a concrete member by a pretensioning method.

[0002]

2. Description of the Related Art As one of the methods of introducing prestress to a concrete member by a pretensioning method without using a strong abutment, it is disclosed in Japanese Patent Application No. 4-152988 at a concrete pouring site. As described above, a conventional PC steel rod (solid PC steel rod) is inserted into the hollow PC steel rod, and this PC steel rod is used as a reaction force bearing member, and a tensile force is applied to the hollow PC steel rod by a jack. The hollow PC steel rod to which the tensile force is applied is placed at a predetermined position of the concrete member, concrete is poured, and the concrete develops to a predetermined strength, and then the hollow PC steel rod is opened. A method of introducing prestress into concrete is known.

[0003]

In the case of the above-mentioned conventional prestress introduction method, at the concrete pouring site,
The PC steel rod inserted in the hollow PC steel rod is used as a reaction force bearing member to apply a tensile force to the hollow PC steel rod to introduce prestress, so that the construction efficiency at the concrete pouring site is improved. There is a drawback in that the construction work efficiency is further reduced because the work cannot be done and the work such as distribution cannot be performed. Therefore, it is necessary to introduce prestress to the hollow PC steel rod at a dedicated place and then transport the prestressed hollow PC steel rod to the concrete pouring site.

[0004]

In order to advantageously solve the aforementioned problems, the prestressed hollow P of the present invention is used.
In the C steel rod fixing device, a stopper 3 for engaging one end of a PC steel rod 2 inserted in the hollow PC steel rod 1 is detachably fixed to one end of the hollow PC steel rod 1. A male screw 4 provided on the outer circumference of the other end of the hollow PC steel rod 1 is screwed into a female screw 6 provided on one end of the support cylinder 5, to form the support cylinder 5
A male screw 9 provided on the outer periphery of the annular locking piece 8 is screwed into a female screw 7 provided on the other end of the ring, and a pressing engaging piece 10 arranged at an intermediate portion in the support cylinder 5 is attached to the annular engaging piece. The PC steel rod 2 is engaged with the stopper 8 to apply a compressive force, and the hollow PC steel rod 1 is subjected to tensile prestress.

[0005]

The present invention will now be described in detail with reference to the examples shown in the drawings. 1 to 4 show a fixing device for a prestressed hollow PC steel rod according to an embodiment of the present invention, FIG. 5 shows a hollow PC steel rod 1 and FIG. 6 shows a PC steel rod 2. There is. 7 and 8 show the support cylinder 5, FIGS. 9 and 10 show the pressure locking piece 10, and FIGS.
Reference numeral 2 denotes an annular locking piece 8.

FIG. 5 shows a hollow PC steel rod 1 used in the embodiment of the present invention. A male screw 11 is provided on the outer periphery of one end of the hollow PC steel rod 1 made of a steel pipe having a circular cross section, and A male screw 4 is provided on the outer periphery of the other end of the hollow PC steel rod 1.

FIG. 6 shows a PC steel rod 2 used in an embodiment of the present invention. A female screw hole 12 is provided at the center of one end of the PC steel rod 2 made of a round steel rod.

FIGS. 7 and 8 show the support cylinder 5, in which a small diameter female screw 6 is provided at one end of a steel cylinder having a hexagonal outer surface 13 and a circular center hole 14. The
Moreover, a large-diameter female screw 7 is provided at the other end.

FIG. 9 and FIG. 10 show a pressing locking piece 10, in which P is provided on the front part of a steel material having a cylindrical outer surface.
A C steel rod insertion hole 15 is provided, and a recess 16 is provided at the rear portion of the steel material. 11 and 12 show the annular locking piece 8, in which a male screw 9 is provided on the outer circumference of the annular locking piece 8 having a circular insertion hole 17.

1 through 4 show the implementation of the present invention, P
1 shows a state in which a C steel rod 2 is used as a reaction force bearing member to apply tensile prestress to the hollow PC steel rod 1, in which the male screw 11 at one end of the hollow PC steel rod 1 is attached to the nut 1
8 is screwed into a nut 18 projecting from one end of the hollow PC steel rod 1, a stopper 3 having a male screw on the outer peripheral surface is screwed, and the fixing bolt 19 inserted into the stopper 3 is , The internal threaded hole 12 of the PC steel rod 2 is screwed, and further, in front of the nut 18 at one end of the hollow PC steel rod 1 (the intermediate side of the hollow PC steel rod 1), the pressure support plate 20 is fitted and supported. The pressure plate 20 is supported by the nut 18.

A nut 21 is screwed into a male screw 4 provided at the other end of the hollow PC steel rod 1, and the hollow PC steel rod 1 is provided in front of the nut 21 (the intermediate side of the hollow PC steel rod 1). At, the pressure bearing plate 22 is fitted and the pressure bearing plate 22 is supported by the nut 21.

A female screw 6 at one end of the support cylinder 5 is screwed into the other end of the hollow PC steel rod 1, and a male screw 9 of an annular locking piece 8 is attached to the female screw 7 at the other end of the support cylinder 5. The pressure locking piece 10 screwed and further fitted to the other end of the PC steel rod 2 is
It is engaged with the annular locking piece 8. In this state, P
A compressive force is applied to the C steel rod 2 and the hollow PC steel rod 1
Pre-stress due to tensile force has been introduced into.

Next, the hollow PC steel rod 1 and the PC steel rod 2 and the members attached thereto are transported to a concrete pouring site, and the portion of the hollow PC steel rod 1 excluding the end portion is embedded in concrete.

As described above, after the tensile force is applied to the hollow PC steel rod 1 and the compressive force is applied to the PC steel rod 2,
PC steel rod set as one unit, a predetermined number of PC steel rod set is arranged at a predetermined position of the concrete member, and the PC
Pour concrete to embed the steel rod set.
After the concrete reaches a predetermined strength, the supporting cylinder 5 is rotated by a wrench to remove it from the hollow PC steel rod 1, and the surface of the hollow PC steel rod 1 is adhered to the concrete.
Apply compressive force to concrete members.

Next, the tensioning device for the hollow PC steel rod used when carrying out the present invention will be described. Horizontal support 2
A support base 42 having a hollow PC steel rod fitting groove 41 opening upward is fixed to the upper surface of one end of the support base 2.
The jack receiving base 28 supporting the cylinder 27 of the hydraulic pushing jack 26 is fixed to the upper surface of the other end of the No. 3, and the hollow PC steel rod fitting upwardly is inserted into the upper surface of the intermediate portion of the supporting base 23. A support 25 having a groove 29 is fixed.

An annular support plate 30 is in contact with the inner surface of the jack receiving base 28, and a piston rod guide member 31 is arranged at the tip end side of the support cylinder 5 of the pushing jack 26, and the annular support plate 30 and Piston rod guide member 31
A spacer 32 made up of a plurality of pipes is interposed between and, and the spacer 32, the annular support plate 30, and the piston rod guide member 31 are joined by welding.

A pair of bolt holding plates 34, 35 each having a hollow PC steel rod fitting groove 33 opening upward are respectively brought into contact with both side surfaces of the support base 25, and four bolts 36 are provided.
Is a jack pedestal 28, a nut 37 abutting on both side surfaces thereof, an annular support plate 30, and a piston rod guide member 3.
1 and the spacer 32, and the support base 25 and the bolt holding plates 34 and 35 that are in contact with both side surfaces of the support base 25, and the nuts 37 are screwed onto the ends of the bolts 36.

A bearing plate 22 that engages with the outer surface of the bolt holding plate 35 is fitted on the hollow PC steel rod 1, and the bearing plate 22 is attached.
The nut 21 for supporting is screwed to the male screw 4 at the other end of the hollow PC steel rod 1. Also, the pushing jack 26
The piston rod 38 in FIG.
Has been inserted into.

Using the hollow PC steel rod tensioning device constructed as described above, the PC steel rod 2 is compressed and the hollow P steel rod is hollowed.
When a tensile force is applied to the C steel rod 1, first, as shown in FIG. 21, the tip end portion of the tip pushing rod 40 of the pressing member 39 is passed through the annular engaging piece 8 and engaged with the pressing engaging piece 10. Then, by extending the pushing jack 26, as shown in FIG.
The steel rod 2 is compressed, and the pressing locking piece 10 is moved toward the other end of the hollow PC steel rod 1.

Next, as shown in FIG. 23, the support cylinder 5 is rotated in the direction D moving toward the intermediate side of the hollow PC steel rod 1, and is annularly screwed to the other end of the support cylinder 5. Locking piece 8
Are engaged with the pressing locking piece 10.

Next, if necessary, the operations shown in FIGS. 21 to 23 are repeated.

[0022]

According to the present invention, the stopper 3 for engaging the one end of the PC steel rod 2 inserted into the hollow PC steel rod 1 is detachably fixed to the one end of the hollow PC steel rod 1. Then, a female screw 6 provided at one end of the support cylinder 5 is screwed into a male screw 4 provided at the outer periphery of the other end of the hollow PC steel rod 1, and a female screw 7 provided at the other end of the support cylinder 5. , A male screw 9 provided on the outer periphery of the annular locking piece 8 is screwed into it, and a pressing locking piece 10 arranged in the middle portion of the support cylinder 5 is engaged with the annular locking piece 8, Since a compressive force is applied to the PC steel rod 2 and a tensile prestress is introduced into the hollow PC steel rod 1, a compressing force is applied to the PC steel rod 2 by using a fixing device having a simple structure and small size. In addition to giving, the hollow PC steel rod 1 can be held and transported while being prestressed by the tensile force.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing a fixing device for a prestressed hollow PC steel rod according to an embodiment of the present invention.

FIG. 2 is a partially cutaway cross-sectional plan view showing a fixing device for a prestressed hollow PC steel rod according to an embodiment of the present invention.

FIG. 3 is a cross-sectional plan view showing a left side portion of FIG. 2 in an enlarged manner.

FIG. 4 is a cross-sectional plan view showing a right side portion of FIG. 2 in an enlarged manner.

FIG. 5 is a partially cutaway enlarged cross-sectional plan view of a hollow PC steel rod.

FIG. 6 is a partially cutaway cross-sectional plan view of a PC steel rod.

FIG. 7 is a cross-sectional plan view showing a support cylinder.

FIG. 8 is a front view showing a support cylinder.

FIG. 9 is a cross-sectional plan view showing a pressure locking piece.

FIG. 10 is a front view showing a pressure locking piece.

FIG. 11 is a cross-sectional plan view showing an annular locking piece.

FIG. 12 is a front view showing an annular locking piece.

FIG. 13 is a cross-sectional plan view showing a state in which a tip pushing rod of a tensioning device for a hollow PC steel rod is brought into contact with a pressing locking piece.

14 is a vertical cross-sectional side view of the portion shown in FIG.

FIG. 15 is a cross-sectional plan view showing an enlarged upper left side portion of FIG.

FIG. 16 is an enlarged cross-sectional plan view showing the lower left portion of FIG.

FIG. 17 is an enlarged cross-sectional plan view showing the lower right portion of FIG.

18 is a cross-sectional view taken along the line AA of FIG.

19 is a cross-sectional view taken along the line BB of FIG.

20 is a sectional view taken along line CC of FIG.

FIG. 21 is a cross-sectional plan view showing a state in which the pressing member of the tensioning device for the hollow PC steel rod is engaged with the pressing locking piece.

FIG. 22 is a cross-sectional plan view showing a state in which a PC steel rod is compressed by a tensioning device for a hollow PC steel rod.

FIG. 23 is a cross-sectional plan view showing a state in which the support cylinder of the tensioning device for a hollow PC steel rod is rotated to compress the PC steel rod and pretension the hollow PC steel rod.

FIG. 24 is a plan view showing a pressing member.

FIG. 25 is a front view showing a pressing member.

[Explanation of symbols]

 1 Hollow PC Steel Rod 2 PC Steel Rod 3 Stopper 4 Male Thread 5 Bearing Tube 6 Female Thread 7 Female Thread 8 Annular Locking Piece 9 Male Thread 10 Pressing Locking Piece 11 Male Thread 12 Female Threaded Hole 13 Hexagonal Outer Surface 14 Circular Center Hole 15 PC Steel Rod insertion hole 16 Recess 17 Insertion hole 18 Nut 19 Fixing bolt 20 Pressure plate 21 Nut 22 Pressure plate 23 Support base 25 Bearing base 26 Pushing jack 27 Cylinder 28 Jack receiving base 29 Hollow PC steel rod fitting groove 30 Annular support plate 31 Piston Rod Guide Member 32 Spacer 33 Hollow PC Steel Rod Fitting Groove 34 Bolt Holding Plate 35 Bolt Holding Plate 36 Bolt 37 Nut 38 Piston Rod 39 Pushing Member 40 Tip Push Rod 41 Hollow PC Steel Rod Fitting Groove 42 Bearing Base

Claims (1)

[Claims] 1. A hollow PC steel rod 1 has a hollow P at one end thereof.
A stopper 3 that engages one end of a PC steel rod 2 inserted in a C steel rod 1 is detachably fixed, and a supporting cylinder is attached to a male screw 4 provided on the outer periphery of the other end of the hollow PC steel rod 1. 5, a female screw 6 provided on one end of the bearing cylinder 5 is screwed, and a female screw 7 provided on the other end of the bearing barrel 5 is screwed with a male screw 9 provided on the outer periphery of the annular locking piece 8 to form the bearing barrel 5 The pressure locking piece 10 arranged in the middle portion of the inside is engaged with the annular locking piece 8 to apply a compressive force to the PC steel rod 2 and to apply a tensile prestress to the hollow PC steel rod 1. Fixing device for hollow PC steel rods with pre-stress introduced.