KR20140049729A

KR20140049729A - Steel strand removing type ground anchor

Info

Publication number: KR20140049729A
Application number: KR1020120115890A
Authority: KR
Inventors: 신종덕
Original assignee: 신종덕
Priority date: 2012-10-18
Filing date: 2012-10-18
Publication date: 2014-04-28

Abstract

The present invention relates to a strand removable type ground anchor, wherein the ground anchor can be fixed very firmly by stably injecting grout at a tip end of a strand and the strand can be removed with certainty by preventing twist of the strand in the first place. The present invention comprises: multiple strands that are inserted to punch holes of a soft ground; an anchor body that is coupled to each tip end for these strands; and an inner member that is installed to one or two anchor bodies. For the ground anchor of the present invention, a tube-shaped protection cap is prepared to cover the tip part of the strand, wherein a tip end of the protection cap is closed to a closed end, a rear tip part is open, multiple grout injection holes are punched at the closed end and surrounds the side wall, the grout hose is extended from the rear end to the tip end of the strand, and the tip end part is inserted through the rear end part of the protection cap in order to be located in the inner space of the protection cap.

Description

Strand Removable Ground Anchor {STEEL STRAND REMOVING TYPE GROUND ANCHOR}

The present invention relates to a ground anchor, and more particularly, by stably injecting grout at the tip of the strand, the fixing can be made very robust, the strand when removing the casing pipe inserted during the drilling of the soft ground The present invention relates to a strand removal type ground anchor that can prevent twisting of the source and completely remove the strand after completion of grouting.

In general, the anchor method is for fixing the structure of civil engineering or construction on the ground, and after connecting with a high-strength tensile material such as a stranded wire and applying a high tensile force to the stranded wire, the restraint or prestress in the transverse or vertical direction is applied to the structure. It is a method of protecting or stabilizing a structure from excessive stress, deformation, displacement, etc. generated in the ground by adding

The anchor used in such an anchoring method is a nail nailed to the ground as it is, and has the effect of tying the ground and the structure into one aggregate, and is generally composed of steel wire and cement grout. Anchors are widely used for supporting earthwork of temporary earth-walls, permanent anchor earth-walls, transmission tower foundations, reinforcing dams, buoyancy anchors of underground structures, and slope reinforcement.

Anchors are classified into rock anchors and ground anchors according to the type of ground to be anchored, and are classified into tiebacks and tie downs according to the direction in which they are installed. It is classified into low pressure anchor and high pressure anchor according to the grout pressure, and it is classified into tension type and compression type according to the way that tension is applied to the grout of the anchor, and stress concentration type and stress according to the stress distribution method applied to the anchor. The stress concentration type is divided into a dispersion type, and the stress concentration type is a method for concentrating the stress on the tip side of the anchor, and the stress distribution type is a method for uniformly distributing the stress throughout the anchoring section of the anchor.

In addition, anchors are classified into removable anchors and permanent anchors according to their service life. The removable anchor is intended to temporarily support the temporary wall or ground within two years of use, and is configured to remove the stranded wire (tensile material) installed in the ground after construction.

The permanent anchor is associated with the remaining period of the structure with a service life of two years or more, and is usually configured not to remove the strand wire installed in the ground to maintain a long term load of two years or more.

On the other hand, the construction sequence using the ground anchor drills the ground to a predetermined depth while rotating or hitting by using hydraulic pressure or pneumatic pressure while the steel casing pipe or rod is mounted on the air rig. As such, after inserting the strand bundle of the anchor body and the lower body into the inserted casing pipe at the same time as the perforation of the ground, the pull-out step by step while rotating the casing pipe, tied to the strand bundle When the grout is injected through the grout hose, the grout is discharged from the bottom of the drill hole, which is the tip position of the strand, and is filled from the bottom to the top.

However, if the ground is soft ground, it is easy to break down a part of the drilling hole during the staged drawing process of the casing pipe.If a part of the drilling hole collapses and the anchor body is buried in the soil, the casing pipe and the strand wire bundle and The rear end of the strand bundle can be rotated by the friction of, and if the strand bundle is rotated, the rear portion is twisted with respect to the tip portion of the strand bundle, so the strands must be removed after the grouting is completed. The disadvantage was that the strand could not be removed.

In recent years, various attempts have been made to prevent twisting of strands by installing tubes outside the strands between the anchor body and the anchor body, which is the tip of the strand strand.

However, such a prior art is because the tube is provided with a diameter so as to surround the outer surface of the strand bundle bundle is to be provided with a grout hose in the longitudinal direction on the outside of the tube, and also in the state that both ends of the tube is blocked by the strand wire spacer Since the adhesive tape is used to fix the tube, the spacer and the strand, the grout has not been properly injected into the inner space of the tube, and thus the anchor and the inner body of the strand are not firmly fixed.

And, in the prior art, when the grout hose is inserted into the boring hole of the ground while the grout hose is fixed to the outer surface of the tube, which is the tip of the strand, the grout hose may be caught with the inner surface of the boring hole. There was a downside.

KR 10-0605287 B1 (2006.07.20.)

The present invention has been researched and developed in view of the above-described disadvantages, by reliably and effectively performing grout injection at the tip of the strand, thereby increasing the frictional force with the grout so that the settlement can be made very firm in the soft ground It is an object to provide a stranded ground anchor.

In addition, the present invention can prevent the twisting of the twisted wire in the source when drawing the casing pipe, and the straight line of the strands are secured to remove the stranded wire to be completely removed when you want to remove the strand after completion of grouting The purpose is to provide a type ground anchor.

The strand removal type ground anchor according to the present invention for achieving the above object is a plurality of strands inserted into the boring hole of the soft ground, an anchor body coupled to each end of the strands, one or two anchor bodies In the ground anchor comprising a load-bearing body to be mounted, a cylindrical protective cap is provided to cover the leading end of the strand, the protective cap is the front end is closed with a closed end and the rear end is open, a plurality of closed end and the main surface side wall Grout injection hole is drilled, the grout hose is extended from the rear end to the tip of the strand is characterized in that the front end is inserted through the rear end of the protective cap is located in the inner space of the protective cap.

The strand includes a first strand and a second strand in which the tip portions thereof are spaced apart at regular intervals and each pair is a pair, and the anchor body is a first anchor body coupled to the tip of the first strand, and the second strand It includes a second anchor body coupled to the tip of the, the protective cap is made of a length that can be covered from the leading end of the first anchor body to the second anchor body and the uneven portion is formed on the side of the protective cap It features.

The rear end of the protective cap is coupled to the anti-twist, the anti-twist is formed by the body and one of the body is fitted with a narrow fitting jaw narrower than the thickness of the body, and the length of the outer peripheral surface of the body and the fitting coupling in the longitudinal direction A plurality of insertion grooves are formed, and the fitting coupling portion is fitted by being fitted to the rear end of the protective cap, and the insertion groove has an arc-shaped first insertion groove through which a first stranded wire passes and a direction perpendicular to the first insertion groove. And a second insertion groove into which the second anchor body is inserted into and inserted into the second anchor groove.

According to the present invention, there is provided a protective cap covering the second anchor body from the first anchor body at the tip of the strand, and a plurality of grout injection holes are formed on the outer circumferential surface of the protective cap so that the grout is external from the inner space of the protective cap. The injection of the grout into the space can be surely and effectively performed grout injection to the tip of the strand, thereby increasing the friction with the grout has the advantage that the settlement can be made very firm in the soft ground.

In addition, the present invention by providing a twist prevention device having a plurality of insertion grooves into which the first stranded wire and the second anchor body are inserted at the rear end of the protective cap, it is possible to prevent the twisting of the stranded wire twisted when the casing pipe is drawn out. In addition, since the straightness of the strands is secured, there is an advantage that can be completely removed when you want to remove the strands after the grouting is completed.

1 is a side cross-sectional view showing a state in which the ground anchor is installed in the drilling hole of the ground according to an embodiment of the present invention.
Fig. 2 is an enlarged view of a portion indicated by an arrow A in Fig. 1 on an enlarged scale.
3 is an exploded perspective view showing the front end portion of the ground anchor according to an embodiment of the present invention.
Figure 4 is an exploded perspective view showing the connection relationship between the second anchor body and the anti-twist of the ground anchor according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. For reference, the size, line thickness, and the like of the components shown in the drawings referred to in describing the present invention may be somewhat exaggerated for ease of understanding. The terms used in the description of the present invention are defined in consideration of the functions of the present invention, and thus may be changed depending on the user, the intention of the operator, customs, and the like. Therefore, the definition of this term should be based on the contents of this specification as a whole.

1 and 2 are diagrams illustrating a strand removed ground anchor according to an embodiment of the present invention.

As shown in the figure, the ground anchor according to the present invention is a plurality of strands (11, 12) to be constructed in the drilling hole (1) in the soft ground and the anchor is detachably coupled to the tip of the strands (11, 12) A sieve 21 and 22, and a lower body 31 and 32 mounted to the anchor bodies 21 and 22, and at the distal end of the strand 11, the strand 11 and the anchor 21 ) And a protective cap 40 which is covered in a shape for accommodating them so as to protect the inner body 31.

The strands 11 and 12 are inserted in the longitudinal direction in the boring hole 1 of the ground, sheath (11a, 12a; sheath, Figs. 3 and 4) of the synthetic resin material on the outer peripheral surface of the strands (11, 12) Of the sheaths 11a and 12a are coupled to the respective anchor bodies 21 and 22. Accordingly, the strands 11 and 12 may not only be protected from moisture or moisture by the sheaths 11a and 12a but also may be easily separated from the ground by not contacting the soil.

Meanwhile, in FIGS. 1 to 4, the strands 11 and 12 in which the sheaths 11a and 12a are covered with the sheaths 11a and 12a are denoted by 11 and 12 for the convenience of description of the drawings. Only the strands 11 and 12 are easily separated from the sheaths 11a and 12a because they have a sufficient tolerance (0.5 to 1.5 mm) with a diameter smaller than the inner diameter of 11a and 12a.

In addition, the strands 11 and 12 are inserted into the drilled hole 1 so that the tip positions thereof have a predetermined distance in the longitudinal direction. For example, as illustrated in FIGS. 1 and 2, the plurality of strands 11 and 12 may include two first strands 11 and two second strands 12, and the tip portions of the first strands 11 may be formed. Is installed in the state inserted into the innermost of the hole 1, the tip of the second strand 12 is constructed to be spaced apart from the tip of the first strand 11 by a predetermined interval (about 2 ~ 2.5m).

Here, although the strand is shown as being constructed only by the two types of the first strand 11 and the second strand 12, but further construction of the strand (not shown) according to the construction environment (that is, the length of the anchorage) In this case, the tip positions of adjacent strands may be spaced apart at a predetermined interval (about 2 to 2.5m).

The anchor bodies 21 and 22 are selectively detachably coupled by clamping the leading ends of the respective strands 11 and 12, and the anchor bodies 21 and 22 are stranded wires 11 inserted therein. , 12) has a built-in structure with wedges and springs for clamping the distal end of the tip and detachable selectively.

The inner body (31, 32) is a basic configuration is formed in the outer surface for increasing the frictional force with the grout, the insertion hole (31a) in which the two strands (11, 12) are inserted or inserted in parallel at regular intervals , 32a and fitting grooves 31b and 32b are formed, and anchor bodies 21 and 22 are mounted on one side of insertion holes 31a and 32a through which the strands 11 and 12 pass.

As mentioned above, the load-bearing bodies 31 and 32 are assembled and constructed in a state where they are mounted together with the respective anchor bodies 21 and 22, and the first anchor for convenience with reference to FIGS. 1 and 2. Coupled with the sieve 21 is called the first load-bearing body 31 and coupled with the second anchor body 22 is called the second load-bearing body (32).

The tip end portion of the first stranded wire 11 is inserted into the insertion hole 31a of the first load bearing body 31 to be clamped to the first anchor body 21, and the insertion hole of the second load-bearing body 32 ( 32a) is inserted into the front end of the second stranded wire 12 and clamped, and the fitting groove 32b formed on the outside of the second lower body 32 in contact with the outer peripheral surface of the first stranded wire 11 Passed.

The protective cap 40 is installed in such a state that the cover cap is fitted from the tip of the stranded wire 11 to the second anchor body 22 mounted on the second load bearing body 32. In the case of soft ground in the process of pulling-out while rotating the casing pipe inserted when drilling, the inside of the drilling hole (1) can be sufficiently protected.

The protective cap 40 is formed by the main surface side wall 42 of the cylindrical structure whose tip is blocked by the closed end 43, and the rear end thereof is open. The front end of the grout hose 51 is inserted into the protective cap 40 through the rear end of the protective cap 40 so that the front end portion 51a is located in the protective cap 40 and the main surface side wall of the protective cap 40. The grout injection hole 41 is formed in the 42 and the closed end 43. The grout hose 51 may be adhesively fixed to the strands 11 and 12 by using an adhesive tape or the like.

In addition, the main surface side wall 42 of the protective cap 40 may be formed in the concave-convex portion 45, such as a spiral structure or annular corrugated portion, the protective cap 40 is injected by the concave-convex portion 45 The grout and friction are increased to be able to be combined more firmly.

Therefore, when the grout is discharged from the tip portion 51a of the grout hose 51 and the through-holes around the grout hose 51, the grout is filled in the inner space of the protective cap 40 and then the plurality of grout injection holes in the inner space of the protective cap 40 ( 41) is discharged to the outer space of the protective cap 40, so that the grout is injected into the outer space as well as the inner space of the protective cap 40 and filled from the lower end of the perforated hole (1) of the soft ground (11, 12) is filled up toward the leading end and the rear end of them and ascends.

On the other hand, the protective cap 40 is preferably made of a length that can cover the front end of the second anchor body 22 from the front end of the first anchor body (21). The rear end of the protective cap 40 is coupled to the twist prevention tool 70 for preventing the twist of the strands (11, 12).

The anti-twist 70 is composed of a body 71 and a fitting portion 72 having a narrower jaw than the thickness of the body 71 at one side of the body 71, and fitting with the body 71. On the outer circumferential surface of the portion 72, a plurality of insertion grooves 73 and 74 are formed in the longitudinal direction, respectively.

The fitting portion 72 of the anti-twist 70 is formed with a thinner end than the thickness of the body 71, the fitting portion 72 is the inner peripheral surface at the rear end of the protective cap 40 When the fitting coupling 72 is inserted and coupled to the protective cap 40, the outer surface of the body 71 is the same as the outer peripheral surface diameter of the protective cap 40, and is thus thick. Becomes In such a state, the rear end of the protective cap 40 and the body 71 of the anti-twisting tool 70 which are fitted and coupled thereto are adhesively fixed using an adhesive tape to protect the protective cap 40 and the anti-twisting tool 70 and the agent. The two anchor bodies 22 are integrated into one.

The insertion grooves 73 and 74 may include a first insertion groove 73 into which a part of an outer circumferential surface of the first stranded wire 11 is inserted, and a second insertion groove into which a tip of the second anchor body 22 is inserted. 74). The grout hose 51 together with the second anchor body 22 should be inserted into the second insertion groove 74. Therefore, the protective cap 40 is installed so as to ride over the second anchor body 22 of the body 71 position in the state where the grout hose 51 is inserted into the fitting portion 72 position of the twist prevention device 70. It may be installed so that only a part of the fitting portion 72 is inserted into the inner circumferential surface.

As mentioned above, the first stranded wire 11 or the second anchor body 22 at each magnetic position inserted into the first insertion groove 73 and the second insertion groove 74 of the twist prevention tool 70. Since the first stranded wire 11 and the second stranded wire 12 coupled to the second anchor body 22 are installed, the straightness of the longitudinal direction can be maintained constant.

In particular, while drawing the drilling hole (1) in the soft ground by drawing the rotating casing pipe to be pulled out step by step from the inside of the hole (1) of the soft ground to the free field beyond the anchorage At this time, in the case of soft ground, a case where a part of the perforation hole 1 of the ground collapses frequently occurs.

Thus, even if a part of the drill hole 1 is collapsed, since the tip portions of the strands 11 and 12 are covered by the protective cap 40, the strands 11 and 12 are twist prevention holes 70 and the protective cap 40. The straightness of the longitudinal direction is maintained by a constant, even if the casing pipe is continuously drawn while the part of the drilling hole 1 is collapsed in this way, the tip portion of the first stranded wire 11, which is relatively weak in structure, is protected by the cap. The second anchor body 22 and the first stranded wire 11 having the inside of the second stranded wire 12 clamped with each other and the rear end of the protective cap 40 by the anti-twisting hole 70 It is fixed as if it were integrated.

Therefore, when the casing pipe is continuously rotated and drawn in a state where a part of the drilling hole 1 is collapsed, there is no fear of twisting of the first strand 11 and the second strand 12.

Draw the casing pipe to the part corresponding to the free field in the same way as above, but draw it out of the packer (not shown) provided in the middle rear position of the strand, then inject grout or air to the packer at a constant pressure to perforate it. When the hole 1 is blocked and the grout is pressurized through the grout hose, the grout discharged from the end is first filled into the protective cap 40 and then discharged through the grout injection hole 41 of the protective cap 40. The drilling hole 1 is filled with a constant pressure. Pressurized injection of such grout is carried out over the second to the third while increasing the pressure, the grout is filled in the drilling hole (1).

As the strands of the strands 11 and 12 are prevented as described above, the grout is completed by injecting grout to the anchorage of the drilled hole 1 at a predetermined pressure, and then completing the grouting in the drilled hole 1 of the soft ground. When you want to remove it has the advantage that it can be removed completely without failure.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. .

11, 12: strand 21, 22: anchor body
31, 32: Lower body 40: Protective cap
41: grout injection hole 42: main surface side wall
43: closed end 70: twist lock
71: body 72: fitting portion
73, 74: Insertion groove

Claims

In the ground anchor comprising a plurality of strands inserted into the boring hole of the soft ground, the anchor body coupled to each tip of the strands, the inner body attached to one or two anchor bodies,
A cylindrical protective cap is provided to cover the tip portion of the strand, and the protective cap is formed of a main surface side wall whose tip is blocked by a closed end, and its rear end is open, and a plurality of grout injections are made to the closed end and the main surface side wall. The ball is drilled,
The strand removal type ground anchor, characterized in that the grout hose is extended from the rear end to the tip of the strand, and the tip is inserted through the rear end of the protective cap and positioned in the inner space of the protective cap.

The method according to claim 1,
The strand includes a first strand and a second strand in which the tip portions thereof are spaced at regular intervals and two pairs are respectively formed.
The anchor body includes a first anchor body coupled to the front end of the first strand and the second anchor body coupled to the front end of the second strand,
The protective cap is made of a length that can be covered from the leading end of the first anchor body to the second anchor body, and the strand wire removal type ground anchor, characterized in that the uneven portion is formed on the side wall of the protective cap.

The method according to claim 2,
The rear end of the protective cap is coupled to the anti-twist, the anti-twist is formed by the body and one of the body is fitted with a narrow fitting jaw narrower than the thickness of the body, and the length of the outer peripheral surface of the body and the fitting coupling in the longitudinal direction A plurality of insertion grooves are formed,
The fitting coupling part is fitted into the rear end of the protective cap, the insertion groove is the first insertion groove of the arc shape through which the first strand is passed, and the second anchor body is inserted and inserted in the direction orthogonal to the first insertion groove Strand removal type ground anchors, characterized in that formed by two insertion grooves.