KR20190043383A - Apparatus for re-providing tension for steel strand of ground anchor - Google Patents

Abstract

Disclosed is an apparatus for re-tensing a strand for a ground anchor. According to an embodiment of the present invention, an apparatus for re-tensing a strand for a ground anchor, capable of re-tensing a strand by fixing the strand to a ground anchor and lifting up an anchor head with an O-ring groove formed on the outer surface, includes: a tension bell holding the anchor head; a hydraulic cylinder lifting the tension bell up from a structure in which the anchor head is placed; and a case placed in the structure to support the hydraulic cylinder.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a tension anchor for a ground anchor,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strand re-tensioning apparatus for a ground anchor, and more particularly to a strand re-tensioning apparatus for a ground anchor which can be used to supplement a reduced tension of a strand constituting a ground anchor.

A ground anchor is a fixing device which is used almost indispensably for civil engineering or construction work. For example, it is used to fix a structure such as a slope wall formed by excavation or an earth retaining wall installed to prevent a ground collapse on a vertical surface .

In general, the ground anchor includes a tensile material, for example a stranded wire. Both ends of the stranded wire are fixed to the ground side and the earth retaining wall side in a state in which the tensile force is applied, so that the earth retaining wall can be pressed and adhered to the ground side.

However, the tensile force applied to the strand at the initial stage of construction of the ground anchor is gradually deteriorated due to the ground incursion which occurs continuously after the elapse of a long time after the construction, and the loss of the soil, so that the ground anchor can fully exercise its function There was a problem that would not exist.

To solve this problem, Korean Utility Model Registration Utility Model No. 20-0481040 discloses a tensile force applying device for a ground anchor that compensates for a reduced tensile force by restraining a stranded wire, that is, fixing it after pulling it back. However, in the Korean Utility Model Registration No. 20-0481040, the compression ring in the first casing must be assembled so as to be surely brought into close contact with the outer circumferential surface of the tensile force head so that the tensile force head can be properly gripped and the tensile force application work of the stranded wire can be performed smoothly. Of course, it is possible to prevent the compression ring or the tension head from being damaged. However, there is a problem in that the compression ring is not adhered to the outer circumferential surface of the tension head often because no reliable fixing means is provided between the tension head and the compression ring.

Korean Registered Patent No. 10-1036013 (2011.05.23, Reinforcement Device for Stranded Wire) Korean Utility Model Registration No. 20-0481040 (2016.08.04, Tensile strength test and application device for ground anchor)

Embodiments of the present invention can provide a strand tensioning device for a ground anchor capable of gripping and retensioning an anchor head with a strand fixed thereon more stably than a conventional one.

According to an aspect of the present invention, there is provided a strand tensioning apparatus for a ground anchor for lifting an anchor head having a strand fixed at a ground anchor and forming an O-ring groove at an outer circumference of the ground anchor, ; A hydraulic cylinder for lifting the tension bell from a structure in which the anchor head is seated; And a case which is seated on the structure and supports the hydraulic cylinder, wherein the tension bell comprises a pair of gripping pieces divided in a longitudinal direction of a hollow cylinder, A grip portion for forming a semicircular protrusion to be inserted into the grip portion; A hook portion into which the grip portion is inserted; A plurality of pressing bolts penetrating through the annular portion and screwed to press the grip portion toward the anchor head; A bell part formed on an inner circumferential surface of a female screw which mates with a male screw formed on an upper outer circumferential surface of the grip part; A tension bar coupled to an upper end of the bell portion and lifted by the hydraulic cylinder; A plurality of wedge pieces which are in close contact with an outer peripheral surface of the anchor head, the plurality of wedge pieces being connected in series to each other through a first spring; A disc portion in which the plurality of wedge pieces are respectively slidably engaged; And a second spring which is coupled to an inner circumferential surface of the bell portion and supports the disc portion. When the bell portion is screwed to the grip portion, the plurality of wedge pieces are guided by a tapered region formed on the inner circumferential surface of the grip portion And the first spring and the second spring are compressed to tightly adhere the wedge piece to the grounding anchor, thereby providing a tensioning device for a ground anchor.

The wedge portion may have a reduced outer diameter in accordance with a tapered region of the grip portion.

The ring portion has an inner diameter larger than an outer diameter of the grip portion in a state where the pair of gripping pieces are in close contact with each other, and can be applied to the anchor head of various diameters.

And a gap adjusting bolt is screwed on the side surface of the grip piece to adjust the distance between the pair of grip pieces.

And a fixing part for restricting the loop part to the grip part.

Wherein the fixing portion comprises: a locking groove formed in the inner circumferential surface of the ring portion such that the lower end thereof is opened and the upper end thereof is closed; And a retaining pin protruding from an outer circumferential surface of the grip piece and inserted into the retaining groove.

The latching groove may be formed in a translucent shape.

The latching groove has a guide groove whose lower end is opened and which extends in the vertical direction; And a locking groove extending from the upper end of the guide groove in the circumferential direction of the ring portion.

According to the embodiments of the present invention, the anchor head is grasped by the grip portion primarily and the anchor head is secondarily held by the wedge portion, so that the anchor head can be gripped more reliably and retreated have. Particularly, in consideration of the fact that an O-ring groove is formed on the outer circumferential surface of the anchor head for coupling an O-ring for blocking a gap between the anchor head and the anchor head cover in order to protect the anchor head normally, And was formed into a ring shape on the inner peripheral surface.

Fig. 1 is a diagram showing a state in which a ground anchor is installed.
FIG. 2 is a perspective view of a strand reinforcement apparatus for a ground anchor according to an embodiment of the present invention. Referring to FIG.
3 is an exploded perspective view showing a strand reinforcement apparatus for a ground anchor in Fig.
4 is a perspective view showing the grip portion.
5 is a front view showing the first gripping piece and the second gripping piece.
6 is a perspective view showing the bell portion.
FIG. 7 and FIG. 8 are schematic views illustrating the operation principle of a strand tensioner for a ground anchor according to an embodiment of the present invention.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, when a component is referred to as " comprising ", it means that it can include other components as well, without excluding other components unless specifically stated otherwise.

Also, throughout the specification, the term " on " means to be located above or below the object portion, and does not necessarily mean that the object is located on the upper side with respect to the gravitational direction.

Furthermore, the term " coupled " does not mean that only a physical contact is made between the respective components in the contact relation between the respective constituent elements, but the other components are interposed between the respective constituent elements, It should be used as a concept to cover until the components are in contact with each other.

The sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, preferred embodiments of a strand tensioner for a ground anchor according to the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals designate like or corresponding components And redundant explanations thereof will be omitted.

Fig. 1 is a diagram showing a state in which a ground anchor is installed.

1, the ground anchor 10 includes an anchor body (not shown) inserted into a perforation hole formed in the ground 20 and fixed by a grout, and an anchor body (not shown) And a plurality of stranded wires 13 each having both ends fixed to the anchor body 11 and the anchor head 11 in a state in which a tensile force is applied to the anchor head 11.

An annular O-ring groove 12 can be formed on the outer circumferential surface of the anchor head 11 and an O-ring 17 for blocking a gap between the anchor head 11 and the anchor head cover 15 is formed in the O- Can be combined.

FIG. 2 is a perspective view of a strand reinforcement apparatus for a ground anchor according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 2, a strand reinforcement apparatus 40 for a ground anchor according to an embodiment of the present invention may include a tension bell 1000, a hydraulic cylinder 2000, and a case 3000.

The tension bell 1000 can be held in close contact with the outer peripheral surface of the anchor head 11 to grip the anchor head 11.

The hydraulic cylinder 2000 can be seated on the upper surface of the case 3000 to lift the tension bell 1000 from the structure 30.

The case 3000 may be formed in a hollow cylindrical shape with an opened lower surface to be seated on the structure 30 and a hydraulic cylinder 2000 may be seated on the upper surface of the case 3000, All or most of the major components of the tension bell 1000 may be disposed in the space. Unless otherwise specified herein, the upper and lower divisions are regarded as being set along a direction perpendicular to the surface of the ground 20 or the structure 30, that is, along the normal direction.

3 is an exploded perspective view showing a strand reinforcement apparatus for a ground anchor in Fig.

3, the tension bell 1000 includes a grip portion 100, a ring portion 200, a fixing portion 300, a pressing bolt 400, a bell portion 500, a tension bar 600, a wedge portion 700, a disc portion 800, and a second spring 900.

Fig. 4 is a perspective view showing the grip portion, and Fig. 5 is a front view showing the first gripping piece and the second gripping piece.

4 and 5, the grip portion 100 may include a pair of gripping pieces 110 and 120. As shown in FIG.

The pair of gripping pieces 110 and 120 may have a shape in which a hollow cylinder that is opened up and down is divided in the longitudinal direction. That is, each of the gripping pieces 110 and 120 may be formed as a hollow semi-cylindrical shape having open top, bottom, and one side.

A semicircular protrusion 111 and a tapered region 113 may be formed on the inner circumferential surface of the first gripping piece 110. When the first gripping piece 110 is in close contact with the outer peripheral surface of the anchor head 11, the anti-circular protrusion 111 is formed to extend in the circumferential direction of the first gripping piece 110, ). The tapered area 113 may be an area where the inner diameter of the first gripping piece 110 decreases toward the bottom and may be disposed on the upper side of the anti-circular protrusion 111.

A male screw 115 that is screwed to the bell part 500 may be formed on an upper outer circumferential surface of the first grip part 110.

A plurality of safety pins 117 may protrude from the lower outer peripheral surface of the first gripping piece 110. The safety pin 117 prevents any drop of the loop 200 and prevents the loop 200 from damaging the structure 30 by colliding with the structure 30. [

A gap adjusting bolt 119 may be screwed on the side surface of the first gripping piece 110. The gap adjusting bolt 119 can adjust the distance between the first gripping piece 110 and the second gripping piece 120 by adjusting the protrusion length. As a result, the gripper 100 can grip the anchor head 11 of various diameters.

The second gripping piece 120 may have the same shape as the first gripping piece 120. That is, the second gripping piece 120 may also have the anti-circular protrusion 121, the tapered area 123, the male screw 125, and the safety pin 127, The adjustment bolt 129 can be screwed.

The hook 200 can prevent the pair of gripping pieces 110 and 120 from spreading to each other.

The hook part 200 may be formed in a hollow cylindrical shape that is opened up and down, and the grip part 100 may be inserted into the inside of the hook part 200.

The hook portion 200 may have an inner diameter larger than the outer diameter of the grip portion 100 in a state where the pair of grip pieces 110 and 120 are in close contact with each other. As a result, the annular portion 200 can allow the grip portion 100 to spread within a certain range by the gap adjusting bolts 119 and 129 to grasp the anchor head 11 of various diameters.

The fixing part 300 restrains the upward and downward movement of the hook 200 so that the position of the hook 200 in the vertical direction is arbitrarily changed so that the pair of the gripping pieces 110 and 120 can be prevented from spreading toward each other have.

The fixing portion 300 may include a locking groove 310 and a locking pin 320.

The latching groove 310 may be formed on the inner circumferential surface of the hook 200 and may include a guide groove 311 and a locking groove 313 to form a translucent shape. The lower end of the guide groove 311 may be opened and extended in the vertical direction and the locking groove 313 may extend in the circumferential direction of the annulus 200 at the upper end of the guide groove 311.

The engaging pin 320 may protrude from the outer circumferential surface of the first gripping piece 110 or the second gripping piece 120.

The hooking pin 320 can be inserted into the guide groove 311 and moved when the hook 200 is moved downward from the upper side of the gripper 100. When the hooking pin 320 is positioned at the upper end of the guide groove 311 The hook 200 can be inserted into the locking groove 313 and moved. As a result, the position of the hook 200 in the up-and-down direction can be fixed.

The pressing bolt 400 may be screwed to the hook 200 to penetrate the hook 200.

The end of the pressing bolt 400 protrudes from the inner circumferential surface of the hook 200 and presses the grip portion 100, specifically, the first gripping piece 110 or the second gripping piece 120 toward the anchor head 11 The grip portion 100 can be brought into close contact with the anchor head 11 more firmly.

The pressing bolt 400 may be disposed on the opposite side of the locking groove 310 with respect to the central axis of the ring 200 to prevent the locking pin 320 from being detached from the locking groove 310.

6 is a perspective view showing the bell portion.

Referring to FIG. 6, the bell part 500 may be formed in a bell shape having a bottom open.

A female screw 510 may be formed on the inner circumferential surface of the bell part 500 to be screwed to the grip part 100. That is, the female screw 510 can be engaged with the male screws 115 and 125.

The tension bar 600 may be coupled to the upper end of the bell unit 500 and extend upward. A nut 610 lifted by the hydraulic cylinder 2000 may be screwed to the upper end of the tension bar 600. The upper end of the tension bar 600 may extend to the upper side of the hydraulic cylinder 2000 through the hydraulic cylinder 2000 and the case 3000.

The wedge portion 700 may include a plurality of wedge pieces 710, 720, 730 and a plurality of first springs 740, 750, 760.

The plurality of wedge pieces 710, 720, and 730 may be connected to each other in series through a plurality of first springs 740, 750, and 760.

The wedge pieces 710, 720 and 730 may have an inner circumferential surface corresponding to the outer circumferential surface of the anchor head 11 so as to be in close contact with the outer circumferential surface of the anchor head 11, The tapered regions 113 and 123 of the gripping pieces 110 and 120 may have an outer circumferential surface having a shape corresponding to the tapered regions 113 and 123. As a result, the thickness of the wedge pieces 710, 720, and 730 can be reduced as they are lowered, and the outer diameter of the wedge portion 700 can be reduced as the wedge pieces 700 are lower.

The wedge pieces 710, 720, and 730 may be slidably coupled to the disc 800. A sliding bolt 770 can be screwed on the upper surface of the wedge pieces 710, 720 and 730 and the sliding bolt 770 can be inserted into a guide hole 810). The guide hole 810 may be formed in a long hole shape.

The disc portion 800 may be formed of a circular annular plate.

The second spring 900 may be coupled to the inner circumferential surface of the bell part 500 and the disc 800 to support the disc 800.

FIG. 7 and FIG. 8 are schematic views illustrating the operation principle of a strand tensioner for a ground anchor according to an embodiment of the present invention.

7 and 8, the anchor head cover 15 and the O-ring 17 are separated from each other in the anchor head 11, and a pair of the grip pieces 110 and 120 are inserted into the outer peripheral surface of the anchor head 11 When the clamp 200 is tightened and then the clamp bolt 400 is clamped and the clamp 500 is screwed to the grip 100 and the tension bar 600 is coupled to the clamp 500, The assembly of the tension bell 1000 can be completed. Next, when the hydraulic cylinder 2000 and the case 3000 are installed and the nut 610 is tightened, the installation of the strand tensioner 40 can be completed. The nut 610 can be lifted by supplying the hydraulic pressure to the hydraulic cylinder 2000 so that the anchor head 11 gripped by the tension bell 1000 can be lifted, So that the stranded wire 13 can be re-tensioned. Finally, when a horseshoe-shaped plate member (not shown) is inserted into the gap formed between the anchor head 11 and the structure 30, the strand 13 is re-tensioned even after removing the strand reinforcement 40 Lt; / RTI >

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10: ground anchor 11: anchor head
12: O-ring groove 13: Stranded wire
15: Anchor head cover 17: O-ring
20: Soil 30: Structure
40: Re-tensioning device of stranded wire 100:
110: first gripping piece 111: semi-circular protrusion
113: tapered area 115: male thread
117: Safety pin 119: Spacing bolt
120: second gripping piece 121: semi-circular protrusion
123: tapered area 125: male thread
127: Safety pin 129: Spacing bolt
200: ring part 300: fixed part
310: latching groove 311: guide groove
313: Locking groove 320:
400: pressure bolt 500:
510: female thread 600: tension bar
610: Nut 700: Wedge part
710, 720, 730: Wedge pieces 740, 750, 760: First spring
770: Sliding bolt 800:
810: Guide hole 900: Second spring
1000: Tension Bell 2000: Hydraulic cylinder
3000: Case

Claims (8)

A strand re-tensioning apparatus for a ground anchor, in which a strand is fixed at a ground anchor and an anchor head having an O-ring groove formed at its outer circumference is lifted to re-tense the strand,
A tension bell for holding the anchor head;
A hydraulic cylinder for lifting the tension bell from a structure in which the anchor head is seated; And
And a case which is seated on the structure and supports the hydraulic cylinder,
The tension bell
A gripping portion formed of a pair of gripping pieces in which a hollow cylinder is divided in the longitudinal direction, and an inner circumferential surface at the lower end of the gripping piece is formed with a semicircular protrusion inserted into the O-ring groove;
A hook portion into which the grip portion is inserted;
A plurality of pressing bolts penetrating through the annular portion and screwed to press the grip portion toward the anchor head;
A bell part formed on an inner circumferential surface of a female screw which mates with a male screw formed on an upper outer circumferential surface of the grip part;
A tension bar coupled to an upper end of the bell portion and lifted by the hydraulic cylinder;
A plurality of wedge pieces which are in close contact with an outer peripheral surface of the anchor head, the plurality of wedge pieces being connected in series to each other through a first spring;
A disc portion in which the plurality of wedge pieces are respectively slidably engaged; And
And a second spring coupled to an inner circumferential surface of the bell portion to support the disc portion,
And the plurality of wedge pieces are brought into close contact with each other by a tapered region formed on the inner peripheral surface of the gripper portion so as to be brought into close contact with the outer peripheral surface of the anchor head when the bell portion is screwed to the gripper portion, And the spring is compressed to tightly adhere the wedge piece to the ground anchor.
The method according to claim 1,
Wherein the wedge portion has a reduced outer diameter in accordance with a tapered region of the grip portion.
The method according to claim 1,
Wherein the loop portion has an inner diameter larger than an outer diameter of the grip portion in a state in which the pair of gripping pieces are in close contact with each other, so that the loop portion can be applied to the anchor head of various diameters.
The method of claim 3,
Wherein a spacing adjusting bolt is screwed on a side surface of the grip piece to adjust an interval between the pair of grip pieces.
The method according to claim 1,
And a fixing portion for restricting the loop portion to the grip portion.
6. The method of claim 5,
The fixing unit includes:
A latching groove having a lower end opened on an inner circumferential surface of the annular portion and an upper end closed; And
And an engaging pin protruding from an outer circumferential surface of the grip piece and inserted into the engaging groove.
The method according to claim 6,
Wherein the engaging groove is formed in a translucent shape.
The method according to claim 6,
The engaging groove
A guide groove whose lower end is opened and which extends in the vertical direction; And
And a locking groove extending from the upper end of the guide groove in the circumferential direction of the annular portion.

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