KR20100046582A - Ground anchor using steel strand and ground reinforcement method using the same - Google Patents

Abstract

PURPOSE: An anchor assembly using a PS strand and a ground reinforcement method using the same are provided to prevent stress corrosion regardless of an anchorage angle, and to improve adhesive power without using a spacer. CONSTITUTION: An anchor assembly using a PS strand comprises a PS strand(10), bulbing retainers(14), a front end stiffener(20), an auxiliary front end stiffener(40), a coil spring(50), and a head fastener. The PS strand has one or more bulbing parts(12). The bulbing retainers are inserted into the bulbing parts. The front end stiffener is coupled to the front end of the PS strand using a wedge(30). The auxiliary front end stiffener is coupled to the front end stiffener using a screw. The coil spring is installed between the front end stiffener and the bulbing parts. The head fastener is coupled to the head of the PS strand using the wedge.

Description

Ground anchor using steel strand and ground reinforcement method using the same}

The present invention relates to an anchor assembly, and more particularly to an anchor assembly using a PS strand that can be used for both soil and rock ground reinforcement and ground reinforcement method using the same.

Earth anchors are used to suppress the ground of the excavation surface from loosening when the foundation is excavated, and rock anchors are used to suppress the wall rock from loosening when the tunnel is excavated. The earth anchor is also called a soil anchor, and the rock anchor is often referred to as a rock bolt because the anchor anchors the PS steel with a nut.

These anchoring method is to stabilize the structure by inserting the sheath and the PS steel into the drilling drilled by drilling machine, and then injecting cement paste or cement mortar to make the anchor body, and after the anchor body is sufficiently hardened to fix the PS steel in the anchor head.

In these anchoring methods, a release PS steel bar is used in which a recess or a convex portion is formed on a surface of the PS steel at a continuous or constant interval. However, in the case of release PS rods inclined at the fixing part or in the case where the PS rods connected to the connecting device are not in a straight line, local bending is applied to the PS rods, which may cause stress corrosion or delayed fracture so that they may be broken later. have. In addition, the weight is not flexible, the workability and workability is poor and expensive and economical.

Meanwhile, the PS steel inserted into the perforation should be spaced apart from the excavation surface so that the grout is tightly filled between the periphery and the perforation and the PS steel is completely covered by the grout. Conventionally, for this purpose, a separate spacer was installed at a predetermined interval on the PS steel, which was very troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to provide an anchor assembly using a PS strand that does not require a separate spacer and can prevent stress angles and delayed fractures at the fixing angles and joints at the fixing portions.

Still another object of the present invention is to provide an anchor assembly capable of obtaining sufficient pullout resistance even when resin is used as a grout material by improving the bearing pressure and adhesion of the tip of the anchor assembly.

It is another object of the present invention to eliminate the need for a separate spacer and to use anchor assemblies using PS strands that can prevent stress corrosion and delayed fracture at the anchoring portion and the joint portion of the fixing portion. It is to provide a ground reinforcement method showing an excellent reinforcing effect.

According to a preferred embodiment of the present invention, a PS strand formed with at least one or more bulging portions along a longitudinal direction, a hollow in which a tip portion of the PS strand is inserted is formed, and an outer end of the PS stiffener having the thread processing and the tip stiffener A first wedge coupled to the distal end of the PS strand, a coil spring coupled between the bulging portion positioned at the distal end of the PS strand and the distal end reinforcement, a hollow into which the head of the PS strand is inserted, and a thread is processed on the outer surface thereof. An anchor assembly is provided comprising a head fastener and a second wedge for coupling the head fastener to the head of the PS strand.

According to another suitable embodiment of the present invention, a bulging holder is inserted in the bulging part to prevent the bulging part from being stretched due to tension force and deforming its shape.

According to another suitable embodiment of the present invention, the tip stiffener is screwed with an auxiliary tip stiffener formed with a pointed conical portion to be inserted more easily through the slime flowing into the hole during the drilling process .

According to another suitable embodiment of the present invention, drilling a hole in the ground to be reinforced and inserting the anchor assembly into the hole, injecting cement paste, cement mortar or resin using an injection hose, cement paste, cement paste Or after the resin is cured, installing the fixing plate to penetrate the head fastening hole coupled to the head of the PS strand, and having a hollow threaded hole in the head fastening hole exposed over the fixing plate, and having an outer surface at an angle to be anchored. There is provided a ground reinforcement method comprising screwing a head to fix an anchor assembly.

According to the present invention, it is possible to prevent stress corrosion or delayed fracture at the joint and to obtain a superior reinforcing effect, regardless of the anchoring angle at the fixing unit, compared to the anchor assembly using the conventional release PS steel rod.

In addition, it is light and flexible, so the work efficiency is good at the construction site, and the adhesion with the grout is excellent, and there is no need for a separate spacer.

In addition, it is possible to prevent deformation or breakage of the bubbling portion that increases the attachment force and the fixing force of the entire anchor assembly.

In addition, the bearing pressure and adhesion of the tip of the anchor assembly are improved, so that sufficient pullout resistance can be obtained even when resin is used as the grout material.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same components or parts are denoted by the same reference numerals as much as possible, and detailed descriptions of related known functions or configurations are omitted.

1 is an exploded perspective view of the anchor assembly according to the invention, Figure 2 is a combined perspective view of the anchor assembly.

As shown, the anchor assembly according to the present invention includes a PS strand 10 having at least one bubbling portion 12 formed therein, a bubbling retaining region 14 inserted into the bubbling portion 12, and a PS strand 10 of the PS strand 10. FIG. Tip reinforcement 20 is coupled to the distal end by using the wedge 30, the distal end reinforcement 40 is screwed to the end reinforcement 20, the end reinforcing sphere 20 is installed between the bulb portion 12 It is composed of a head fastener 60 is coupled to the head of the coil spring 50 and the PS strand 10 by using a wedge 30.

In the steel strand, two strands twisted into two twisted wires (S strands) and seven strands made by twisting six strands of S strands around one strand are used. In the present invention, 7 stranded strands are used. At least one bulbous portion 12 was formed at predetermined intervals. The bulbing part 12 refers to a portion in which the twisted PS strand is inflated and its diameter is increased compared to other portions. This operation of inflating the CS strand is called bulbuling. A method known in the art may be used as a method of forming the bulb part 12, and for example, clamps both sides with a clamp and spaces the gap between the parts to form the bulb part 12. By applying a compressive force, the twisted strand can be inflated to form the bulging part 12.

This bulging part 12 serves to increase the spacer and the mechanical adhesion. In other words, the PS strand used as the anchor steel is difficult to coat the strand evenly with concrete like PC members (PC girder, PC slab), so it is necessary to pay attention to corrosion when the permanent anchor, the present invention 12 The PS strands are spaced apart from the periphery of the perforations so that the PS strands can be uniformly covered by the grout material. In addition, since the bulging part 12 becomes a kind of protrusion on the PS strand having a smooth surface, the friction force with the grout material is increased, and consequently, the adhesion force is increased. In addition, the inside of the bulb part 12 is filled with a grout material, the bulb part 12 is filled with a grout material to form a kind of bulb to increase the anchoring force of the PS strand as anchor steel. In addition, by appropriately adjusting the spacing of the bulbous portion 12, the bulbous portion 12 may serve to reinforce the natural deflection of the flexible PS strand.

And the inside of the bulb part 12 may be inserted into the bulb holder (14) to prevent the shape of the bulb 12 is deformed or destroyed against external force. That is, the bulb portion 12 also serves to restrain the grout material filled therein, the shape of the bulb portion 12 may be deformed or destroyed by an external force acting on the bulb portion 12. For example, when the anchor assembly is tension-fixed, the bulging portion may be extended by the tension force, and thus the shape may not be maintained. However, when the bubbling retainer 14 is inserted therein, the bulging retainer 14 not only prevents the deformed or destroyed by the rigidity of the bubbling retainer 14 itself, but also provides a restraining effect of the grout material filled therein. It can be raised even further. The bubbling retaining region 14 is not particularly limited as long as it can maintain the shape of the bubbling unit 12 against external force, and for example, a steel bar or a steel or plastic bead may be used. The method of inserting the bulbous holding region 14 into the bulbous portion 12 may include inserting the bulbous holding region 14 into the space between the element wires that are opened when the bulbous portion 12 is formed.

Prevents the tip portion of the twisted PS strand 10 from releasing in the process of inserting the PS strand 10 into a hole drilled into the ground or rock to be reinforced, and more easily inserts the flexible PS strand 10 into a small punch. The front end reinforcing hole 20 is coupled to the tip of the PS strand 10 to prevent the pull out the PS strand 10 by acupressure. The tip reinforcement hole 20 has a hollow so that the PS strand 10 can be inserted therein, so that the wedge 30 feeds the PS strand 10 into the hollow velocity of the tip reinforcement hole 20. 20 is firmly fixed to the PS strand 10. And the outer surface of the tip stiffener 20 is threaded to improve the adhesion performance with the grout material, in particular resin, and to easily combine the auxiliary tip stiffener 40 as necessary.

The wedge 30 has a tapered shape corresponding to the hollow of the tip reinforcement 20 and is divided into two or three, and each divided wedge piece 32 is coupled to an elastic band 34. And each wedge piece 32 is coupled to have a predetermined space (36) due to the space (36) is wedge 30 is penetrated into the protruding reinforcement hole (20) tightly entered into the PS strand (10). Distinguish the head fastener 60, which will be described later, from the wedge 30 for coupling the tip stiffener 20 to the tip of the PS strand 10, from the wedge 30 for coupling the head to the head of the PS strand 10; It is referred to as the first wedge for the purpose.

Meanwhile, in order to prevent the wedge coupling from being released and detached in the process of inserting the tip reinforcement member 20 fixed to the wedge 30 into the hole of the ground to be reinforced, the auxiliary reinforcement member 40 is provided at the tip reinforcement member 20. Can be further combined. Auxiliary tip reinforcement 40 has a function to allow easier insertion through the slime flowing into the hole in the drilling process in addition to this purpose. To this end, the auxiliary tip reinforcement 40 forms a cone portion 42 by sharpening its end. Therefore, by further combining the auxiliary tip reinforcement (40) through the slime through the cone portion 42 can be easily inserted and by the tip reinforcement (20) and the auxiliary end reinforcement (40) of the PS strand 10 As the tip diameter becomes larger, the pressure strand can be more effectively resisted by the acupressure. And in order to obtain greater pull resistance, the cone portion 42 may have a larger diameter than other portions of the auxiliary tip reinforcement.

The coil spring 50 is coupled between the bulb portion 12 and the tip reinforcement 20. This coil spring 50 becomes a kind of protrusion on the PS strand having a smooth surface, thereby increasing the frictional force with the grout material and consequently increasing the adhesion. The anchoring force of the tip is very important in the behavior of the anchor assembly. In the present invention, as described above, the anchor assembly is pulled out until the anchor assembly exerts a required tensile force through the tip stiffener 20 and the auxiliary tip stiffener 40. It was not. In addition, in the present invention, the coil spring 50 is further coupled between the bulging part 12 and the tip stiffener 20 so as to resist drawing by additional attachment force.

The head fastener 60 is coupled to the head fastening line 60 so that the anchor assembly according to the present invention can be simply fixed in the nut method. To this end, a thread is processed on the outer surface of the head fastener 60. And the head fastener (60) is hollow so that the PS strands 10 can be inserted so that the wedge (30) bites into the hollow of the head fasteners (10) to the head fastener 60 head fasteners 60 is firmly fixed to the PS strand 10.

The wedge 30 has a tapered shape corresponding to the hollow of the head fastener 60 and is divided into two or three, and each divided wedge piece 32 is coupled to an elastic band 34. And each wedge piece 32 is coupled to have a predetermined space (36) due to the space (36) is wedge 30 is penetrated into the protruding reinforcement hole (20) tightly entered into the PS strand (10). This wedge 30 for coupling the head fastener 60 to the head of the PS strand 10 is distinguished from the wedge 30 for coupling the tip reinforcement 20 described above to the head of the PS strand 10. It is referred to as a second wedge for the purpose.

The anchor assembly according to the present invention configured as described above can be constructed in the same way as using a deformed steel reinforcement as anchor steel.

3 is an exploded perspective view for explaining a method of reinforcing the ground using the anchor assembly according to the present invention, Figure 4 is a perspective view for explaining a method for reinforcing the ground using the anchor assembly according to the invention, 5 is a cross-sectional view showing a state reinforcing the ground using the anchor assembly according to the present invention.

First, the reinforcement tip 20 is coupled to the tip of the reinforcing target ground with a hole, and the P.S. strand 10 having at least one bubbling portion 12 is inserted therein. The bubbling portion 12 of the PS strand 10 may be further provided with a bubbling retaining region 14, the auxiliary tip reinforcing hole 40 may be further coupled.

Next, grout materials such as cement paste, cement mortar, and resin are injected using an injection hose.

Next, the head fastener 60 is fixed to the head of the exposed PS strand 10 by the wedge 30 and the fixing plate 70 is installed by penetrating the head fastener 60. The fixing plate 70 has a rectangular shape as a whole, and a hole 72 into which the PS strand 10 is inserted is formed at the center thereof.

Finally, the anchor head 80 is fastened to the head fastener 60 to fix the anchor assembly. In this case, tension force may be introduced to the anchor assembly before coupling the anchor head 80 if necessary. Anchor head 80 is a kind of nut, the upper end is angled in a hexagon to be rotated using a wrench or the like, the hollow thread is formed to be screwed to the head fastener (60).

The present invention has been described above in detail by using an embodiment. The presented embodiments are exemplary and can be made by those skilled in the art to various modifications and modifications to the disclosed embodiments without departing from the spirit of the present invention. The scope of the invention is not limited by these modifications and variations, but only by the claims appended below.

1 is an exploded perspective view of an anchor assembly according to the present invention.

2 is a combined perspective view of the anchor assembly according to the present invention.

Figure 3 is an exploded perspective view for explaining a method of reinforcing the ground using the anchor assembly according to the present invention.

Figure 4 is a perspective view for explaining the method of reinforcing the ground using the anchor assembly according to the present invention.

5 is a cross-sectional view showing a state reinforcing the ground using the anchor assembly according to the present invention.

Claims (4)

PS strand formed with at least one bubbling portion along the longitudinal direction, A hollow tip is formed in which the tip portion of the PS strand is inserted and the outer end of the PS reinforcement is thread-processed, A first wedge for coupling the distal end reinforcement to the distal end of the PS strand; A coil spring coupled between the bulging portion and the tip reinforcing hole positioned at the distal end of the PS strand, The head fastening hole is formed in the hollow is inserted into the head of the PS strands and the thread is processed on the outer surface and And a second wedge for coupling the head fastener to the head of the PS strand. According to claim 1, An anchor assembly, characterized in that the bulge holding portion is inserted into the bulging portion to prevent the bulging portion from being deformed due to tension. The method of claim 2, The tip reinforcement hole anchor assembly characterized in that the auxiliary tip reinforcement is formed screwed to the pointed cone portion to be inserted more easily through the slime flowing into the hole during the drilling process. Drilling a hole in the ground to be reinforced and inserting the anchor assembly according to any one of claims 1 to 3 into the hole; Injecting cement paste, cement mortar or resin using an injection hose, After the cement paste, cement paste or resin has cured, installing a fixing plate to penetrate the head fasteners coupled to the head of the PS strand; and A method of reinforcing the ground, wherein the head fastener exposed to the fixing plate has a hollow threaded portion and an upper end portion of the outer surface is screwed to an angled anchor head to fix the anchor assembly.

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