KR102033261B1 - Restrain apparatus improved in wedge installation structure and constructing method using the same - Google Patents

Abstract

The present invention discloses a re-tensioning apparatus, which includes a tubular member, a wedge assembly, a wedge moving lever, a cover member, a tension bar and a nut member, wherein the wedge assembly advances in the tubular member to be provided on a circumference of an anchor head to become a fastening readiness state as the wedge moving lever moves in a contact end direction of the tubular member through a first long hole and is separated from the anchor head to become a standby state as the wedge moving lever is hung on a second long hole after moving in a fastening end direction of the tubular member through the first long hole.

Description

RESTRAIN APPARATUS IMPROVED IN WEDGE INSTALLATION STRUCTURE AND CONSTRUCTING METHOD USING THE SAME}

The present invention relates to a re-tensioning device and a construction method using the same, and more particularly, a re-tensioning device used for construction to reinforce the tension by re-tensioning the ground anchor (Anchor) installed for reinforcement of the ground and the like and construction using the same It is about a method.

Ground anchors are reinforcing structures used for the purpose of preventing excessive displacement and collapse of the ground. Ground anchors are widely used for supporting and reinforcing various structures and retaining walls, as well as preventing and stabilizing slopes.

In general, the ground anchors are prestressed by the cement paste injected by the grouting method while the PS steel wire, the PS steel wire, the PS steel bar, and the like are used as the tensile material and inserted into the ground.

As shown in FIG. 1, the ground anchor includes a tension member 3 inserted into the ground, and an outer end of the tension member 3 is an anchor which is a fixing device installed on a predetermined pressure plate 2 exposed to the outside of the ground. It is connected to the anchor head 1. The length section of the tension member (3) is a tension portion (A) which is installed so that the friction with the ground substantially to transfer the tension force of the anchor head (1), and the ground force by the frictional resistance or pressure resistance of the ground It is divided into an anchor body (B) which is a resistor portion to transmit to.

Ground anchors having the configuration described above are required to maintain and re-tension because the residual tension of the tension member decreases due to changes in conditions such as relaxation of the tension member, drying shrinkage of the concrete, and deformation of the ground according to time after construction. .

Re-tensioning construction to compensate the tension of ground anchors is to screw the re-tensioning device to the screw tap formed on the outer circumferential surface of the anchor head, and tension the anchor head and the tension member by using a force device such as jack. And insert the fixing wedge into the gap formed between the anchor head and the pressure plate. The technique regarding a retension apparatus and a construction method is disclosed by patent document 1.

By the way, the conventional re-tension construction method as described above has a disadvantage that it is difficult to design a universal re-tension device because only the re-tension device that meets the specifications of the anchor head on which the screw tab is formed.

In addition, the retension construction is performed after a long time of about 10 years after the initial tension is applied, so that the thread tap of the anchor head is old and the coupling with the retension device is impossible or the coupling is released during the operation. There is a problem that causes the need for countermeasures.

On the other hand, the conventional re-tension construction method has a disadvantage in that the coupling work for coupling the re-tension device to the anchor head is not easy to take a lot of time. In addition, in the re-tensioning construction, tens of tons of tensile force is normally applied, so if the re-tensioning device is not firmly and stably anchored to the anchor head, there is a concern that a safety accident may occur due to separation between the anchoring head and the re-tensioning device.

Patent Document 1: Korean Patent Publication No. 10-1757713

The present invention was devised in view of the above problems, and is configured to be disposed around the anchor head by selectively moving a plurality of tightening wedges at one time, a wedge that can quickly and easily perform the coupling operation for the anchor head The purpose of the present invention is to provide a retensioning device having an improved installation structure and a retensioning construction method using the same.

In order to achieve the above object, the present invention is disposed on the pressure plate so as to surround the anchor head of the ground anchor, and the tapered portion is formed to gradually narrow the inner diameter as it goes to the contact end and the internal thread of the fastening end opposite to the contact end A tubular member having an additional portion formed therein and having lever latch holes formed on both sides thereof having a first long hole extending in a longitudinal direction and a second long hole communicating with the first long hole and extending in a horizontal direction; A taper is formed around the anchor head and is disposed in the gap between the tubular member and the anchor head, and the taper gradually becomes thinner toward the end thereof, and has a rounded inner wall corresponding to the curvature of the outer circumferential surface of the anchor head. A wedge assembly having a plurality of tightening wedges each having a rounded outer wall corresponding to the curvature of the tapered portion of the tubular member, the horizontal cross section having an arc shape; A wedge moving lever interlocking with the wedge assembly and protruding out of the tubular member through the lever locking hole; A cover member having a male screw portion that can be screwed to the female screw portion of the tubular member in a state where the tightening wedges are inserted into the tubular member, and a fastening hole formed in a center thereof; A tension bar which is screwed to the fastening hole of the cover member and is provided with a tension force from a tension jack installed on a support tube disposed to be mounted on the pressure plate while surrounding the tubular member; And a nut member screwed through the rear end of the tension bar and transmitting a tension force applied from the tension jack to the tension bar, wherein the wedge moving lever is directed toward the contact end of the tubular member through the first long hole. As the wedge assembly moves forward in the tubular member and is disposed around the anchor head, the wedge assembly is ready for tightening, and the wedge moving lever moves through the first long hole in the direction of the fastening end of the tubular member. The wedge assembly is separated from the anchor head in accordance with the second long hole provides a re-tensioning device characterized in that the standby state.

In the tubular member, the second long hole extends in both directions from an upper end of the first long hole, so that the lever locking hole is formed in a 'T' shape.

The wedge assembly may include a plurality of connecting springs arranged in a circle so that the tightening wedges surround the anchor head and interposed between the tightening wedges to elastically support the adjacent tightening wedges. .

The tightening wedges may be assembled to a lower surface of a single support ring disposed concentrically with the tubular member inside the tubular member, and the wedge moving lever may be assembled by screwing to the side of the support ring.

The upper edge portion is disposed above the support ring in the tubular member, and a plurality of first bolts are inserted into and fastened downward at a predetermined interval to be assembled with the support ring, and the center portion of the tubular member is inserted and fastened upwards. And a support plate mounted at a lower end of the tension bar, wherein the first bolt is fitted with a coil spring so as to be interposed between the support ring and the support plate.

The tightening wedges have a cross-sectional shape inclined such that the inner wall extends vertically toward the end and the outer wall goes toward the end.

According to another aspect of the invention, (a) the tapered portion is formed to gradually narrow the inner diameter toward the contact end, the female thread is formed on the inner wall of the fastening end opposite to the contact end, and both sides are extended in the longitudinal direction Preparing a tubular member formed of a cylindrical member made of a metal material having a diameter larger than that of the anchor head of the ground anchor, the lever engaging hole having a first hole and a second long hole communicating with the first long hole and extending laterally; (b) a taper is formed that gradually decreases in thickness toward the end, and has a rounded inner wall corresponding to the curvature of the outer peripheral surface of the anchor head and a rounded outer wall corresponding to the curvature of the tapered portion of the tubular member. Preparing a wedge assembly comprising a plurality of tightening wedges having an arc cross section; (c) assembling the wedge assembly to the lower portion of the support ring, fastening the support plate to the upper portion of the support ring, and fixing the support plate to the bottom of the tension bar made of long bolts; (d) preparing a cover member having a male screw portion that can be screwed with the female screw portion of the tubular member and having a fastening hole formed at a center thereof, and coupling the cover member to the tension bar; (e) Inserting the wedge assembly provided with the support ring and the support plate into the tubular member while holding the tension bar and engaging the cover member with the female screw portion of the tubular member to open the upper opening of the tubular member. Capping; (f) screwing a wedge moving lever to the support plate through the lever locking hole; (g) moving the wedge moving lever toward the fastening end direction of the tubular member through the first long hole and engaging the second long hole to set the wedge assembly to a standby state; (h) disposing the tubular member on the acupressure plate while holding the tension bar such that the contact end of the tubular member is in contact with the acupressure plate surrounding the anchor head; (i) moving the wedge moving lever in the direction of the contact end of the tubular member through the first long hole to advance the wedge assembly in the tubular member and to place it around the anchor head so that it is ready for tightening; ; (j) installing a support barrel on the pressure plate to be mounted on the pressure plate while surrounding the tubular member; (k) installing a tension jack as a tensioning device on the bearing barrel; (l) screwing the nut member through the rear end of the tension bar and positioning the upper portion of the tension jack; (m) actuating the tension jack to push the nut member hydraulically to exert a tensile force on the nut member; (n) the tension bar and the tubular member are pulled by the tension force applied to the nut member to narrow the gap between the tightening wedges so as to tension the anchor head in the state where the circumference of the anchor head is tightened by the tightening wedges. Adding; And (o) inserting a fixing wedge into a gap formed between the anchor head and the pressure plate by the displacement of the anchor head according to the tension applied to the anchor head to fix the retensioning state. A method is provided.

According to the present invention, since the wedge assembly can be conveniently disposed or separated around the anchor head by operating the wedge moving lever, it is convenient to install and dismantle the retension device.

In addition, the re-tensioning device according to the present invention can shorten the working time since the wedge assembly is coupled to the anchor head in a pre-mounted state in the tubular member.

The following drawings attached to this specification are illustrative of the preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.
1 is a cross-sectional view schematically showing a construction example of a general ground anchor.
Figure 2 is a perspective view showing the appearance of the re-tension device according to a preferred embodiment of the present invention.
3 is an exploded perspective view of FIG. 2.
4 is a plan view schematically showing the arrangement of the support ring and the wedge assembly in FIG.
5 to 10 is a cross-sectional view showing a re-tension construction method using a re-tension device according to an embodiment of the present invention step by step.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

Figure 2 is a perspective view showing the appearance of the re-tension device according to a preferred embodiment of the present invention, Figure 3 is an exploded perspective view of FIG.

2 and 3, a retension device according to a preferred embodiment of the present invention is inserted into the tubular member 10 and the tubular member 10 arranged to surround the anchor head 1 of the ground anchor. And a wedge assembly (14) consisting of a plurality of tightening wedges (15) assembled at the bottom of the support ring (17), and with the tightening wedges (15) inserted into the tubular member (10). A wedge moving lever 13 protruding out of the tubular member 10 through a cover member 21 for capping the opening and a lever engaging hole 12 interlocked with the wedge assembly 14 and formed in the tubular member 10. And a tension bar 22 connected to the tubular member 10 to transmit a tensile force.

The anchor head 1 is a fixing device connected to the outer end of the tension member 3 inserted into the ground, and is made of a disk-shaped rigid block having a round outer peripheral surface.

The tubular member 10 is constituted by a cylindrical body of metal material larger in diameter than the anchor head 1 so as to surround the anchor head 1 of the ground anchor when the retension device is installed. The tubular member 10 is provided with a tapered portion to gradually narrow the inner diameter while going to the contact end in contact with the pressure plate (2) during installation. In addition, a female screw portion 11 is formed on the inner wall of the fastening end opposite to the contact end.

Both sides of the tubular member 10 are composed of a first long hole 12a extending in the longitudinal direction (length direction) and a second long hole 12b communicating with the first long hole 12a and extending in the horizontal direction (circumferential direction). The lever locking hole 12 is formed. In consideration of the ease of operation of the wedge moving lever 13 to be described later, it is preferable that the lever locking hole 12 is formed in a substantially 'T' shape.

The plurality of tightening wedges 15 constituting the wedge assembly 14 are disposed in the gap between the tubular member 10 and the anchor head 1 and tightly tightened around the outer circumferential surface of the anchor head 1 during retensioning. Each of the tightening wedges 15 is substantially arcuate in cross section of the body, and the outer peripheral surface 15b is inclined obliquely to form a tapered structure to gradually become thinner toward the end. For tight coupling with the anchor head 1, the tightening wedge 15 has a cross-sectional shape in which the inner wall extends vertically to the end and the outer wall goes to the end and is inclined. The tightening wedge 15 has an inner wall rounded in the circumferential direction corresponding to the curvature of the outer peripheral surface of the anchor head 1 and an outer wall rounded in the circumferential direction corresponding to the curvature of the tapered portion of the inner wall of the tubular member 10.

The inner wall of the tightening wedge 15 is formed with a concave-convex structure 15a for preventing the sliding by increasing the frictional resistance upon contact with the anchor head (1). At this time, the concave-convex structure 15a is preferably configured in a form in which a plurality of string-shaped protrusions are formed at predetermined intervals while going in the height direction of the tightening wedge 15.

3 and 4, the tightening wedge 15 has a plurality of wedge assemblies 14 arranged in a circular shape with a predetermined clearance space therebetween so as to surround the anchor head 1 when the retension device is installed. ). Tightening wedge 15 may be provided along the circumference of the anchor head 1 is divided substantially at equal intervals to provide a stable and effective tightening function in the peripheral four directions with respect to the center of the anchor head (1).

The connecting spring 16 is interposed between the tightening wedges 15 to elastically connect and support between the tightening wedges 15 adjacent to each other. When the re-tensioning construction is performed on a vertical surface or a slope, the plurality of tightening wedges 15 are supported by each other by the connecting spring 16 to maintain the shape, thereby preventing the arrangement state from being disturbed by external impact or self-weight.

The connecting spring 16 consists of an elastic coiled spring that can be compressed and restored by a certain displacement when a force is applied in the state installed between the tightening wedges 15.

Spring fixing holes 15c are formed at both ends of the arc in the longitudinal direction of the tightening wedges 15 to install the connection springs 16. Both ends of the connecting spring 16 are tightly inserted into and supported by the spring fixing holes 15c provided in the different tightening wedges 15 adjacent to each other.

The support ring 17 is disposed concentrically with the tubular member 10 inside the tubular member 10 to fix the wedge assembly 14. The tightening wedges 15 of the wedge assembly 14 are assembled with a hexagon wrench bolt 24 at the bottom of the support ring 17. The hexagon wrench bolts 24 are preferably fastened one by one to the top center of each tightening wedge 15. The support ring 17 has a long hole 17a extending in the radial direction of the support ring 17 to radially fasten the hexagon wrench bolts 24 and is radially formed from the center of the support ring 17. .

The support plate 18 is disposed above the support ring 17 inside the tubular member 10, and a portion near the top edge is inserted into and fastened downward by a plurality of first bolts 19 at predetermined intervals. It is assembled with the ring 17. The center plate 18b is formed in the support plate 18, and the second bolt 26 is inserted into the tension bar 22 positioned upward through the center hole 18b from the lower surface of the support plate 18. do. Accordingly, the support plate 18 is mounted on the lower end of the tension bar 22.

It is preferable that the bearing 20 is seated in the center hole 18b of the support plate 18 so that the tension bar 22 can be freely rotated with respect to the support plate 18. According to this structure, the cover member 21 is conveniently formed on the upper inner wall of the tubular member 10 by turning the tension bar 22 while the cover member 21 is fixed to the lower end of the tension bar 22. ) And the tension bar 22 may be connected to the tubular member 10 at the same time as capping the upper opening of the tubular member 10.

The first bolt 19 penetrates through the support plate 18 and is engaged with the support ring 17, and each of the first bolts 19 is provided between the lower surface of the support plate 18 and the upper surface of the support ring 17. Coiled spring 25 is fitted to perform a cushioning function. The first bolt 19 is composed of a guide bolt having no thread for a predetermined length from the head portion and a thread formed only at an end thereof, and serves as a guide during the buffering action of the coil spring 25.

The wedge moving lever 13 is assembled by screwing to the side of the support ring 17 as shown in Figure 4 so that the outer end penetrates the 'T' shaped lever locking hole 12 of the tubular member 10 It protrudes out of the tubular member 10. The wedge moving lever 13 is provided with at least one pair symmetrically on both sides of the support ring 17. Therefore, the operator can operate the wedge assembly 14, which is connected to the support ring 17 by holding the wedge moving lever 13 in both hands, to move forward and backward.

According to the operator's operation, the wedge assembly moves as the wedge moving lever 13 moves toward the contact end of the tubular member 10 through the first long hole 12a of the lever engaging hole 12, that is, downward (vertical direction). 14 moves forward in the tubular member 10 and is arranged around the anchor head 1 to become a tightening ready state. Further, according to the operator's operation, the wedge moving lever 13 is moved toward the fastening end of the tubular member 10 through the first long hole 12a, that is, upwardly (vertical direction), and then again horizontally. The wedge assembly 14 is separated from the anchor head 1 as it is caught by the two long holes 12b, and becomes a standby state.

The tension bar 22 of the long bolt structure in which the male screw part 23 is formed in the outer peripheral surface is screwed in the fastening hole in the center of the cover member 21. The cover member 21 can be screwed to the upper opening of the tubular member 10 and capped by rotating the tension bar 22 while the tension bar 22 is fully screwed into the fastening hole and integrated.

The cover member 21 has a male screw portion 21a which is screwable to the female screw portion 11 of the tubular member 10 in a state where the tightening wedges 15 are inserted into the tubular member 10 on the outer circumferential surface thereof and has a tension at the center thereof. Bar 22 is provided with a fastening hole that can be screwed.

When the cover member 21 is screwed into the female threaded portion 11 of the tubular member 10, the coiled spring 25 interposed between the support plate 18 and the support ring 17 is supported by the support ring 17. By pressing the lower tightening wedges 15 with elastic force, an even force is applied to the respective tightening wedges 15.

The tension bar 22 is fastened to the tubular member 10 by the nut member 42 is fastened to the male screw portion 23 through the rear end when the device is operated.

The tension jack 40 is disposed on the supporting barrel 30 which is mounted on the pressure plate 2 while surrounding the tubular member 10 to provide a tension force for lifting the anchor head 1 from the pressure plate 2.

When the tension jack 40 is operated and the plunger 41 is advanced by hydraulic pressure, the nut member 42 is pushed to apply a tension force to the tension bar 22 and the tubular member 10, wherein the tubular member 10 is a tightening wedge. Substantially integrated with the anchor head (1) in the state (15) is interposed to act to pull the anchor head (1) spaced apart from the pressure plate (2).

Then, the re-tension construction method using the re-tension device according to the preferred embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 5, the anchor head 1 of the ground anchor to be retensioned has a structure in which no thread tab is formed on the outer circumferential surface thereof and is positioned on the pressure plate 2.

6 to 7, a process of arranging the tubular member 10, on which the wedge assembly 14 is assembled, on the pressure plate 2 in a state where the worker grips the tension bar 22 by hand (not shown). Is shown.

At the beginning of construction, as shown in FIG. 6, the wedge assembly 14 remains in a standby position at a position retracted from the contact end of the tubular member 10. In the stand-by state, the wedge moving lever 13 is caught in the second long hole 12b of the lever locking hole 12 to fix the retracted state of the wedge assembly 14 and between the support plate 18 and the support ring 17. The intervening coiled spring 25 is compressed to compress the wedge assembly 14 with elastic force.

As shown in FIG. 7, the wedge movement lever 13 is slightly rotated along the second long hole 12b in a state where the tubular member 10 is disposed on the pressure plate 2, and then advanced along the first long hole 12a. At the same time, the elastic force of the coil spring 25 acts to advance the wedge assembly 14 toward the contact end. When the ends of the tightening wedges 15 constituting the wedge assembly 14 come into contact with the pressure plate 2 and the arrangement is completed, the retension device is switched to the tightening preparation state. Accordingly, in the gap between the anchor head 1 and the tubular member 10, a plurality of tightening wedges 15 constituting the wedge assembly 14 are arranged to be circularly inserted around the anchor head 1. .

Subsequently, as shown in FIG. 8, the support barrel 30 is installed on the pressure plate 2 to surround the tubular member 10, and the tension jack 40 is disposed on the support cylinder 30 as shown in FIG. 9. After installation, the nut member 42 is fastened through the rear end of the tension bar 22.

When the construction preparation setting is completed as described above, when the tension jack 40 is operated as shown in FIG. 10, the tension bar 22 and the tubular shape are pushed by pushing the nut member 42 while the plunger 41 is advanced by hydraulic pressure. A tensile force is applied to pull the member 10 and the anchor head 1 backward in a batch. At this time, the tubular member 10 is substantially integrated with the anchor head 1 with the tightening wedge 15 interposed therebetween. Due to the interaction between the tapered portion formed on the inner surface of the tubular member 10 and the tightening wedge 15, the anchor head 1 is not detached to the front of the tubular member 10, and is usually a material having tens of tons of tension applied thereto. It will stably remain bitten by the retension device under tension construction conditions.

When the tubular member 10 is pulled backward by the tension force, the plurality of tightening wedges 15 are tightened around the anchor head 1 to be in close contact.

When the fixing wedge 50 of a predetermined shape is inserted into the gap formed between the anchor head 1 and the pressure plate 2 by the displacement of the anchor head 1, the retension state is fixed.

As described above, the present invention has a remarkable effect that the wedge assembly 14 can be quickly and conveniently disposed or separated around the anchor head by operating the wedge moving lever 13.

The present invention can perform the re-tensioning construction in the state of holding the anchor head using the tightening force of the re-tensioning device, it can be applied to multi-purpose anchor head having a variety of sizes and shapes.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

1: anchor head 2: pressure plate
3: tension member 10: tubular member
11: female thread part 12: lever locking hole
12a: First Chapter 12b: Second Chapter
13: wedge shift lever 14: wedge assembly
15: Tightening Wedge 16: Connecting Spring
17: support ring 18: support plate
20: bearing 21: cover member
22: tension bar 25: coiled spring
30: base 40: seal jack
42: nut member 50: fixing wedge

Claims (7)

The tapered portion is disposed on the pressure plate to surround the anchor head of the ground anchor and gradually narrows inward as it goes to the contact end. A tubular member having a first latch hole and a lever engaging hole formed by a second long hole communicating with the first long hole and extending in a horizontal direction;
A taper is formed around the anchor head and is disposed in the gap between the tubular member and the anchor head, and the taper gradually becomes thinner toward the end thereof, and has a rounded inner wall corresponding to the curvature of the outer circumferential surface of the anchor head. A wedge assembly having a plurality of tightening wedges each having a rounded outer wall corresponding to the curvature of the tapered portion of the tubular member, the horizontal cross section having an arc shape;
A wedge moving lever interlocking with the wedge assembly and protruding out of the tubular member through the lever locking hole;
A cover member having a male screw portion that can be screwed to the female screw portion of the tubular member in a state where the tightening wedges are inserted into the tubular member, and a fastening hole formed in a center thereof;
A tension bar which is screwed to the fastening hole of the cover member and is provided with a tension force from a tension jack installed on a support tube disposed to be mounted on the pressure plate while surrounding the tubular member; And
And a nut member screwed through the rear end of the tension bar and transmitting a tension force applied from the tension jack to the tension bar.
As the wedge moving lever moves in the direction of the contact end of the tubular member through the first long hole, the wedge assembly moves forward in the tubular member and is disposed around the anchor head to be ready for tightening, and the wedge movement After the lever is moved in the direction of the fastening end of the tubular member through the first long hole, the wedge assembly is separated from the anchor head as the second long hole catches the air,
The tightening wedges are assembled to a lower surface of a single support ring disposed concentrically with the tubular member inside the tubular member,
The wedge moving lever is assembled by screwing to the side of the support ring,
The upper edge portion is disposed above the support ring in the tubular member, and a plurality of first bolts are inserted into and fastened downward at a predetermined interval to be assembled with the support ring, and the center portion of the tubular member is inserted and fastened upwards. And a support plate mounted at a lower end of the tension bar.
The first bolt is re-tensioning device characterized in that the coiled spring is inserted so as to be interposed between the support ring and the support plate to perform a buffer function. The method of claim 1,
And the second long hole extends in both directions from an upper end of the first long hole so that the lever locking hole is formed in a 'T' shape. The method of claim 1,
The wedge assembly,
The tightening wedges are arranged in a circle to surround the anchor head,
And a plurality of connecting springs interposed between the tightening wedges to elastically support the adjacent tightening wedges. delete delete The tapered portion is disposed on the pressure plate to surround the anchor head of the ground anchor and gradually narrows inward as it goes to the contact end, and a female thread is formed on the inner wall of the fastening end opposite to the contact end, and extends in the longitudinal direction on both sides. A tubular member having a first latch hole and a lever engaging hole formed by a second long hole communicating with the first long hole and extending in a horizontal direction;
A taper is formed around the anchor head and is disposed in the gap between the tubular member and the anchor head, and the taper gradually becomes thinner toward the end thereof, and has a rounded inner wall corresponding to the curvature of the outer circumferential surface of the anchor head. A wedge assembly having a plurality of tightening wedges each having a rounded outer wall corresponding to the curvature of the tapered portion of the tubular member, the horizontal cross section having an arc shape;
A wedge moving lever interlocking with the wedge assembly and protruding out of the tubular member through the lever locking hole;
A cover member having a male screw portion that can be screwed to the female screw portion of the tubular member in a state where the tightening wedges are inserted into the tubular member, and a fastening hole formed in a center thereof;
A tension bar which is screwed to the fastening hole of the cover member and is provided with a tensile force from a tension jack installed on a support tube disposed to be mounted on the pressure plate while surrounding the tubular member; And
And a nut member screwed through the rear end of the tension bar and transmitting a tension force applied from the tension jack to the tension bar.
As the wedge moving lever is moved toward the contact end of the tubular member through the first long hole, the wedge assembly moves forward in the tubular member and is disposed around the anchor head to become a tightening preparation state. After the lever is moved in the direction of the fastening end of the tubular member through the first long hole, the wedge assembly is separated from the anchor head as the second long hole catches the air,
The wedge assembly,
The tightening wedges are arranged in a circle to surround the anchor head,
And a plurality of connection springs interposed between the tightening wedges to elastically support adjacent tightening wedges.
The tightening wedge has a cross-sectional shape of the retension device characterized in that the inner wall is extended vertically while going to the end and the outer wall is gradually inclined to become thinner toward the end. In the re-tension construction method for the ground anchor,
(a) The tapered portion is formed to gradually narrow the inner diameter toward the contact end, and a female thread is formed on the inner wall of the fastening end opposite to the contact end, and the first long hole and the first long hole extending in both directions on both sides; Preparing a tubular member formed of a cylindrical member made of a metal material having a diameter larger than that of the anchor head of the ground anchor, the lever engaging hole formed of a second long hole communicating with and extending in the transverse direction;
(b) a taper is formed that gradually decreases in thickness toward the end, and has a rounded inner wall corresponding to the curvature of the outer peripheral surface of the anchor head and a rounded outer wall corresponding to the curvature of the tapered portion of the tubular member. Preparing a wedge assembly comprising a plurality of tightening wedges having an arc cross section;
(c) assembling the wedge assembly to the lower portion of the support ring, fastening the support plate to the upper portion of the support ring, and fixing the support plate to the bottom of the tension bar made of long bolts;
(d) preparing a cover member having a male screw portion that can be screwed with the female screw portion of the tubular member and having a fastening hole formed at a center thereof, and coupling the cover member to the tension bar;
(e) Inserting the wedge assembly provided with the support ring and the support plate into the tubular member while holding the tension bar and engaging the cover member with the female screw portion of the tubular member to open the upper opening of the tubular member. Capping;
(f) screwing a wedge moving lever to the support plate through the lever locking hole;
(g) moving the wedge moving lever toward the fastening end direction of the tubular member through the first long hole and engaging the second long hole to set the wedge assembly to a standby state;
(h) disposing the tubular member on the acupressure plate while holding the tension bar such that the contact end of the tubular member is in contact with the acupressure plate surrounding the anchor head;
(i) moving the wedge moving lever in the direction of the contact end of the tubular member through the first long hole to advance the wedge assembly in the tubular member and to place it around the anchor head so that it is ready for tightening; ;
(j) installing a support barrel on the pressure plate to be mounted on the pressure plate while surrounding the tubular member;
(k) installing a tension jack as a tensioning device on the bearing barrel;
(l) screwing the nut member through the rear end of the tension bar and positioning the upper portion of the tension jack;
(m) actuating the tension jack to push the nut member hydraulically to exert a tensile force on the nut member;
(n) the tension bar and the tubular member are pulled by the tension force applied to the nut member to narrow the gap between the tightening wedges so as to tension the anchor head in the state where the circumference of the anchor head is tightened by the tightening wedges. Adding; And
(o) inserting a fixing wedge into a gap formed between the anchor head and the pressure plate by the displacement of the anchor head according to the tension force applied to the anchor head to fix the re-tension state; .

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