JP2867075B2 - Removable ground anchor and ground anchor construction method using it - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to construction of civil engineering structures, construction of an underground continuous wall, construction of an underground ground anchor after construction, and completion of construction. The present invention relates to a ground anchor that can be easily dismantled and removed later and an anchor construction method using the ground anchor.

Description of the Related Art Generally, when constructing high-rise buildings, subways and other large underground structures, as the depth goes deeper under the ground, H-shaped steel is fixed vertically to the surroundings, and a large branch tree is used for retaining walls. Or, a water blocking wall will be formed. In this case, the surrounding earth pressure received by the horizontal plate installed reaches several hundred tons as it enters the basement, and eventually it becomes impossible for the retaining wall etc. to withstand the pressure, causing a large accident to collapse. obtain.
Correspondingly, in order to prevent the collapse of the retaining wall, using a large H-shaped steel, installing a steel support having a complicated structure connecting the retaining wall horizontally and vertically on both sides of the excavated underground space. There is also. However, such steel support works are obstacles to the smooth installation of construction equipment due to the steel support structures installed on the grids, so the work efficiency is reduced, the construction period is extended, the construction cost is increased, and Despite its usefulness, such as wasting iron, it has many problems.

In addition, another construction method, the underground continuous wall construction method, has a drawback that the surface of the wall is irregular and the surface needs to be finished, and in this case, there is also a problem that it becomes a pollution factor such as noise and dust. . Therefore, the construction of the continuous wall by the anchor method is widely used.

Anchors used as wall supports are used to prevent the movement or distortion of buildings at groundwater seepage, slopes, earthquakes, etc. There is a temporary ground anchor which is an underground fixed structure to be removed later.

U.S. Pat.No. 4,592,178 provides a swingable connection of a plurality of winged arms, with the arms extending into a borehole to perform an anchoring function, while U.S. Pat. It also provides a method to remove the soil in the pipe and leave the mortar inside to achieve the anchor function, but since the formed anchor tension material remains as it is, it will be a serious problem after the completion of construction There are cases.

Japanese Patent Publication No. 3-77891 and Japanese Patent Publication No. 2-5206,
A spacer and a tension fastening structure are obtained by driving a core material that can be separated and removed at the center into a drilling hole, and integrating and anchoring around the periphery using various types of tension fastening structures, and then removing the center core material. The present invention provides a method using a removable anchor that can pull out and remove a tensile material by breaking a fastening structure between the anchors. However, there is a problem that it is not possible to maintain a strong connection between the spacer and the tensile agent fastening structure around the center core.

On the other hand, Japanese Patent Publication No. 3-77891 discloses a core material having a tapered cone portion, a tension member located around the core material and having a tip joined to a groove of the tension material in the tapered cone portion, and each piece of the tapered cone portion. The anchor material can be removed because the tension material is extruded over the entire length and released from the grout material by pulling up the tapered cone part over the entire length of the anchor, which is composed of a hollow material located between them. It is. In addition, other Japanese Tokuhei 2-52
No. 06 is composed of an unbonded core material, a plurality of spacers located around the core material and decomposed when the core material is removed, and a tendon material located on the outer periphery of the core material and the spacer, When the core material is removed, the spacer is disassembled, and the tendon material connected to the spacer is removed.

However, in such a case, since only one side wall is attached to the spacer or the like, it is not possible to pull out the tendon material so as to sufficiently withstand the lateral soil pressure, and it is necessary to insert these anchors into the excavation holes. Even when assembling the body, it is difficult to insert and fix it in the drilling hole while maintaining these assembled states, as well as it is bonded and integrated with the surrounding mortar, so it is not separated well, ,
The fact is that it is a theoretical idea that cannot be applied at the construction site.

In order to overcome the above-mentioned drawbacks, the present inventor inserts a multi-part pressure taper cone 2 into a cylinder 1 as shown in FIG.
Is inserted, and the binding taper cone 4 to which the tension member 5 is bound is inserted and fixed, the cap 6 is covered, and the tension member is strongly strained so that the anchor function can be exhibited. An anchor body was developed as described above (Korean Patent Application No. 93-17615). However, since the anchor body is also bound and anchored by the anchor body for each unit, the bundle body is entangled and the vibration load becomes excessively high when a vibration force is applied for disassembly. The disadvantages are not pointed out.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cylinder, an anchor disassembly cone arranged at the center of the cylinder, and a plurality of anchor tension cones arranged around the anchor disassembly cone in order to solve the above problems. And to provide a ground anchor that can be easily removed after grouting and curing.

Another object of the present invention is to provide an anchor method for removing the ground anchor after grouting and curing using the removable ground anchor.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, aspects and other advantages of the present invention will be more clearly understood from the following detailed description in conjunction with the accompanying drawings.

FIG. 1 is an exploded perspective view of a conventional dismountable ground anchor.

FIG. 2 is an exploded perspective view of a dismountable ground anchor according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state where the dismountable ground anchor of the present invention is cast on the ground.

FIG. 4 is a sectional view showing the disassembled ground anchor of the present invention after assembly.

FIG. 5 is a partially cutaway perspective view of the cylinder of the dismountable ground anchor according to the present invention.

6A and 6B are perspective views showing a closed state and an opened state of a tension member binding cone portion of the dismountable ground anchor according to the present invention.

7 to 9 are cross-sectional views showing a dismantling removal process of the dismountable ground anchor according to the present invention.

FIG. 10 is a cross-sectional view showing a state in which the dismountable ground anchor of the present invention is disassembled after grouting work and curing.

11 to 13 are plan views showing another embodiment of the dismountable casting anchor according to the present invention.

FIG. 14 is a view corresponding to FIG. 10 showing another embodiment of the present invention.

Description of the Preferred Embodiment As shown in FIGS. 2, 4 and 5, the cylindrical cylinder 10 of the present invention includes a plurality of outer peripheral holes 12 radially arranged around a central through hole 11 on a central dividing screen 14. Perforated, so that there is a difference in height (d) between the central through hole 11 and the outer peripheral hole 12, the cylinder inner peripheral wall 15 from the top surface 13 to the central division screen 14,
A plurality of cylindrical grooves 16 for accommodating the binding cone are formed by the number corresponding to the tensioning material binding cone for tensioning the anchor, leaving the center portion screen 14 to the lower ridge portion 13c as being hollow, and leaving the hollow portion around the cylinder. The screw part 17 was formed on the upper part.

As shown in FIG. 6, the anchor disengaging tensile material binding cone 20 and the anchor tensioning tensile material binding cone 20 'of the present invention are
In the form of a truncated cone, a concave and convex portion 18 is formed on the inner peripheral surface of the hollow portion, a ring groove 19 is formed on the outer periphery of the large diameter, and an elastic ring 21 is inserted and coupled to this ring groove, The multi-part united split pieces 20a, 20b, 20c abut the notches 22 to maintain an integrated conical shape. The diameter of the internal tension member insertion hole 23 of the binding cone was made slightly smaller than the diameter of the tension member to ensure airtightness after assembly.

Although the tensile material binding cone for anchor disassembly and the tensile material binding cone for anchor tension of the present invention have the same size and diameter as each other, they are efficient in production and use,
If necessary, the size and the diameter can be made different to change the strength and the assembling property. However, there is no difference in the fact that the multi-pieces are mutually integrated by the elastic ring 21.

As shown in FIG. 2, the spacer 30 of the present invention is in contact with the outer peripheral surface of the central member and also the outer peripheral surface of the tension member binding cone 20, so that the contact surfaces 30 a, 30 b, and 30 c are formed in a cylindrical shape. Although it was possible to make close contact with each other during assembly,
If necessary, it can be configured as a simple rod, polyhedron, or configured to support two or more binding cones, and large enough to maintain the distance between the binding cone and the center member. (See FIGS. 11, 12, and 13). As can be seen from the cross-sectional structure, the upper portion of the spacer 30 has a greater thickness than the lower portion, so that the spacer 30 is perpendicular to the center member 31.

As shown in FIG. 4, the center member 31 of the present invention has a slightly smaller diameter on the lower surface than the center through hole 11 so as to be mounted on a projection 11b such as a snap ring inserted into the lower groove 11a of the center through hole 11 of the cylinder. It was formed and the upper surface was reduced so that the outer peripheral tangent seemed to form an acute angle with respect to the plane from top to bottom.

Tensile material used in the present invention is usually a wire or PC
When the steel wire is assembled inside the binding cone 20, the uneven portion 18 of the inner peripheral surface of the binding cone is tightened to the surface of the steel wire by the tension of the elastic ring 21 so as not to be easily detached.

In addition, two or more bolt holes 13b are formed in the upper ridge portion 13a of the skirt portion of the cylinder 10 of the present invention, and the bolt holes 13b are also formed in the lower ridge portion 13c. Multiple guide holes 45 with a diameter slightly larger than the diameter
The upper lid 40 and the lower lid formed corresponding to the part of the binding cone
41 can be fastened with a normal bolt 42.

Further, by forming a guide boss 43 protruding to the outside in the guide hole formed in the lower lid 41, a more stable disassembly and assembly operation can be guided.

The cap 50 of the present invention has a space 52 within which the fastening cone 20 can sufficiently rotate, and a screw portion 51 is formed on the inner periphery of the inlet of the cap. The screw portion 17 is screwed.

The process of installing and dismantling the ground anchor based on the above structural features will be described for each process.

1. Excavation Step An excavation hole 61 having a predetermined length is formed in the ground 60 by an excavator or the like using a casing pipe.

2. Assembling process of anchor body After inserting the ends of the respective tension members (w) into the binding cone 20 of the present invention and placing the center member 31 on the lower protrusion 11b of the center through hole 11, the center member 31 The tension member binding cone 20 for dismantling the anchor body into which the tension member (w) is inserted is inserted. Along the outer peripheral wall of the central member 31, the spacer 30 corresponding to the number of the cylindrical grooves 16, the base of which contacts the boundary between the outer peripheral hole 12 and the central through hole 11, and the contact surface 30 a leans on the outer periphery of the central member 31. Install as follows. Thereby, the tension member bundling cone 20 ′ for tensioning the anchor body along the radially arranged outer peripheral holes 12.
When a tensile member (w) whose end is connected to a binding cone is inserted into the space so as to pass through the outer peripheral hole 12 and exit to the lower portion of the cylinder, and then pulled, the space shown in FIG.
Is completed.

In this state, the upper cover 40 is assembled by using bolts 42 so that a part of the tension member (w) of each binding cone 20 is exposed, and the lower cover 41 is penetrated by the tension member (w). After that, the screw part 51 of the cap 50 and the cylinder screw part are screwed to each other to form a strong anchor body.

3. Anchor body insertion fixing step The anchor body assembled in the above step 2 is pushed down to the bottom of the excavation hole 61 in the above step 1, and the packer 64 and the spacer are inserted.
At 65, the tension member (w) is prevented from becoming entangled, and the sheath tube 66 surrounds the tension member.

A normal grouting operation is performed to seal the drilled hole 61, cure it, and fix the anchor body.

4. Tension Anchor Step After fixing the pedestal 62 to the shielding plate 67, the end of the pulled-out anchoring material tensioning material binding cone 20 'is firmly fastened and fixed to the pedestal 62 by a metal fitting.

5. Anchor dismantling process When the tensile material (w ') coming out of the anchor material disassembling tensile material binding cone 20 inserted into the center member is pulled by a strong force, the protrusion 11b cannot withstand the pressure of the center member 31. (FIG. 7), the center member 31, the anchor member disassembly tension member binding cone 20 and the tension member (w ') engaged with it are pulled out to the ground via the sheath tube 66 and removed. You. At that moment, the tension member binding cone 20 'for tensioning the anchor body, which has been tensioned with a force of several thousand kilograms to several tens tons, is displaced to the center side due to the detachment of the center member 31 which provided the drag, and the structure collapses Will be. At this time, by engaging the tension member with the vibrator and vibrating strongly, as shown in FIGS. 8 and 9, the lower part of the binding cone spreads over the outer peripheral hole 12 or the retaining ring 12a, so that it comes off from the tension member. Will be. Thus, when the tensile member (w) is pulled out, it is released to the ground via a sheath tube (FIG. 10).

FIG. 14 shows a state in which the anchor body is cured and fixed together with a tensile material or the like according to another embodiment of the present invention and then decomposed.

As described above, the disassemblable anchor body of the present invention is easy to assemble, and after assembling, even if mortar is present in the periphery, the tensile member can be pulled out to the ground by disassembling the binding cone, Providing the correct tensile force can greatly improve construction stability.

Further, the tension can be several hundreds to several tens times higher than that of the conventional anchor body, and the number of drilled holes per unit area can be greatly reduced, thereby greatly reducing the construction cost.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E02D 5/76 E02D 5/80

Claims (5)

(57) [Claims] 1. A plurality of outer peripheral holes radially arranged around a central through hole are formed in a central portion screen, a height difference is provided between the central through hole and the outer peripheral hole, and a height difference is provided from the uppermost surface to the central portion screen. A plurality of cylindrical grooves for accommodating the binding cone along the inner circumferential wall of the cylinder are formed as many as the number of tensioning material binding cones for anchor tension. A cylinder with a threaded part and a concave part on the inner peripheral surface of the truncated conical hollow part,
A ring groove is formed on the upper side of the large diameter, so that an elastic ring is inserted into this ring groove, and the notch of the multi-part united cone piece is abutted to form a conical anchor disassembly tension. A material binding cone and a tensioning material binding cone for anchor tension; a contact surface in contact with the outer peripheral surface of the tensioning material binding cone formed as a cylindrical concave surface; a spacer having a polyhedral structure in which an upper portion is formed thicker than a lower portion; A center material in the form of a truncated cone with a hollow formed so that it is slightly smaller than the hole and smaller at the top, so that the outer tangent is apparently at an acute angle to the plane, and a diameter slightly larger than the diameter of the tensile material A plurality of guide holes are pierced radially at the center and periphery corresponding to the location of the binding cone to form a bolt fastening hole, and a plurality of guide holes with a diameter slightly larger than the diameter of the tensile material. The lower lid has a hole for bolt fastening, a bolt guide hole is formed on one side, and a space where the fastening cone can rotate. A removable ground anchor, comprising: a cap having a threaded portion formed on an inner peripheral surface of the lower opening. 2. The method according to claim 1, wherein two or more bolt holes are formed in the upper ridge portion of the upper skirt portion of the cylinder, and a plurality of bolt holes are also formed in the lower ridge portion of the lower skirt portion. A removable ground anchor according to claim 1. 3. A tensioning material binding cone includes an anchor tensioning cone and an anchor disassembling cone, which are the same or different in size and diameter, and are divided into at least two or more divided pieces. A removable ground anchor according to claim 1. 4. The removable ground anchor according to claim 1, wherein the diameter of the hollow portion inside the tension member binding cone is slightly smaller than the diameter of the tension member. 5. A ground anchoring method using a ground anchor according to claim 1, wherein a drilling hole of a predetermined length is formed in the ground by a drilling machine or the like using a casing pipe. An end portion of the tension member is bound to an internal through hole of the anchor disassembling tension member binding cone, and the tension member is attached to an inner hollow portion of the center member placed on a lower protrusion of a center through hole of the cylinder. Inserting and fixing the tensile material binding cone for anchor disassembly bound with the spacer, the spacers corresponding to the number of the cylindrical grooves are provided along the outer peripheral wall of the center member at the boundary between the outer peripheral hole and the central through hole at the base thereof. Are placed so that the contact surface is in contact with the outer peripheral wall of the central member, the tensile material is bound to the anchor tension pulling material binding cone, the outer peripheral hole is penetrated, and the anchor tension pulling material binding cone is coupled. And the upper lid and A ground anchor assembly process concluded serial under cover covering the cap, said push assembly has been ground anchor to the lowest bottom of the borehole, to prevent tension member is tangled with packers and spacing member,
After fixing through the sheathed pipe, grouting work is performed on the outside of the sheathed pipe to cure the soil anchoring process.After fixing the pedestal to the shielding plate, the anchor tension of the tensile material exposed on the ground Anchor tensioning process, in which the tension material coming out of the tensioning material binding cone is strongly fixed to the pedestal with fasteners, and only the tensioning material that came out of the anchor disassembly tensioning material binding cone among the tensioning materials exposed on the ground is cylinder Pull out with enough strength to break the projection at the lower part of the center through hole of the center hole so that the center material is detached from the cylinder, disassemble the tension material binding cone for anchor disassembly and the binding of the tension material and put the tension material on the ground Extracting, then vibrating the tension material in the anchoring tensioning material binding cone around the damaged structure, and then pulling it out to the ground. Ground anchor construction method according to claim.