WO2012067454A2

WO2012067454A2 - Borehole-diameter-expanding drill having the function of maintaining the shape of the reamed area in the ground, and a pile and tension member construction method for building work using the same

Info

Publication number: WO2012067454A2
Application number: PCT/KR2011/008814
Authority: WO
Inventors: 임성대; 현재호; 조형권
Original assignee: 주식회사 삼일이엔씨
Priority date: 2010-11-18
Filing date: 2011-11-17
Publication date: 2012-05-24
Also published as: WO2012067454A3; KR101077960B1

Abstract

The present invention relates to a borehole-diameter-expanding drill which is used in order to expand the hole wall in part of a borehole shaft drilled in the ground for the purpose of building work, wherein there is a sliding blade assembly which comprises sliding blades capable of mutual folding, hinged to the shaft part of a rotor at the upper end thereof, and each of the sliding blades has secured to the upper surface thereof cutting bits for hole-wall cutting, and there is a movable member for controlling the upwards unfolding and the downwards folding of the sliding blades, and thus it is possible to subject part of the borehole shaft to reaming in the ground while maintaining the shape of the reamed area in the ground unaltered, and it is possible to form the securing and fixing part of an anchor or tension pile or else to form the spread foundation part at the front end of a compression pile by casting concrete into the reamed area.

Description

Drilling diameter drill with the shape-keeping function of underground expansion and construction method for pile and tension member

The present invention relates to a method and apparatus for constructing a compression member or a tension member in a construction work, and in particular, perforated diameter drill to provide a foundation for improving the structural performance of the pile or anchor widely used in the construction field in relation to the ground And it also relates to a method of efficiently constructing the pile and anchor using him.

In general, the construction field uses a variety of drills for the construction of tension members, such as piles used in the foundation of the structure, anchors for buoyancy prevention anchors, slope stability and other ground related structures. The entire drilling length is drilled with the same diameter.

In this way, if the drill is drilled to the same diameter, the drilling operation is simple and easy, but most of the drilling should be carried out to a solid ground such as weathered rock or soft rock, which can be firmly supported by structural members. Particularly, in the case of a compression member such as a pile (a ready-made pile, a cast-in-place pile, a single pile integrated with a pillar), even if it drills deeply to a solid ground, the area of the perforated tip is small so that the structural member supports the ground even if it bears enough external force. Surrender (exceeds allowable capacity).

In addition, in the case of a tension member such as an anchor or a tension pile, a tension member is inserted into a hole already drilled. Therefore, when a load is applied to the anchor, pull resistance is too small to resist drawing, so most anchor bodies are moved to a solid rock layer. After punching and inserting, the injection material such as cement grout is injected into the triplet and cured in the hole to increase the frictional resistance and adhesion resistance to secure the pullout resistance.

It is necessary to secure as much drawing resistance as necessary within the small diameter of the drilled hole, so that the length of drilling is long, the structure of the anchor body and the construction order are complicated, and the amount of injection material is excessive, resulting in high construction cost and damage to the natural environment of the ground. There was a problem that the environmental pollution contained in the polluted to a range of several hundred meters to more than one area around the ground.

Until recently, various kinds of tools have been developed for extending the diameter of the ground for improving their performance, and an example of the method of extending the diameter of the drilling using the same is as follows.

1) Method of widening the space by applying pulse to the required position in the ground. An example of such a method is disclosed in Korean Laid-Open Patent Publication No. 10-2007-0079197 "Prepared Pile-Integrated Pulse Discharge Pile Method", and FIG. 4 is a representative view of the accompanying drawings.

2) Method of arranging bulbs such as concrete at the distal end of the hole by irregularly expanding a part of the hole after the first drilling. An example of such a method is disclosed in Korean Patent Registration Publication No. 10-0951632 "Granular material ground consolidation injection method using a tip grout injection device", 5 of which are representative drawings.

3) A method of expanding a part of the drilling hole to a certain shape after the first drilling. An example showing such a method is disclosed in Korean Laid-Open Patent Publication No. 1985-0008512 "Split Bucket Type Rotary Excavation Apparatus", and FIG. 3 of the accompanying drawings is a representative view showing an extended state of a perforated hole.

The three cases have their advantages, but they also have the following problems.

First, it is difficult to guarantee the concrete placement of a certain size in the ground where it is difficult to check with the naked eye.

Secondly, while maintaining a part of the drilling hole (mainly the drilling tip), the shape maintenance of the expansion hole is not guaranteed. More specifically, as shown in (a) of FIG. 1, when a part of the drilling hole 24 (mainly the drilling end portion 26) which is previously drilled in the ground is expanded without a separate hollow wall retaining device, the hollow expansion portion Injecting water for cooling the drill drill together with air flows into (24a) and sometimes a large amount of groundwater flows in, so that the upper base of the expansion portion 24a is loosened, as shown in FIG. 1 (b), near the expansion portion 24a. This is because a problem arises that the wall of the wall collapses.

Third, it is difficult to install concrete and reinforcement of exact size by design for the part where the vacant wall is expanded. That is, as shown in (b) of FIG. 1, debris debris 28 is accumulated in the expansion space of the perforated hole tip portion 26, which is the concrete of the exact size for the formation of the pile foundation or the tension member fixing fixture It makes the installation of reinforcement difficult.

Fourth, due to the structural characteristics of the cutting tool, it is possible to cut and expand the ground to a level of solid soil layer, but it is difficult to expand the rock layer much harder than that.

Therefore, if a drill is implemented that can solve these problems, it will be greatly appreciated by many users or construction workers.

Accordingly, it is an object of the present invention to provide a drill diameter expansion drill to ensure the shape of the expansion portion is secured while expanding a portion of the drilling hole (mainly drill tip) previously drilled in the ground.

Another object of the present invention is to ensure the concrete placement of a certain standard even in the drilled hole in the ground which is difficult to check with the naked eye and to precisely expand the drilling to facilitate the installation of the concrete and reinforcement of the exact specifications by the design for the expanded part of the wall To provide a drill diameter expansion drill that can be.

Still another object of the present invention is to provide a drill diameter expansion drill capable of cutting not only a hard soil layer but also a hard rock layer in expanding a part of a drilled hole.

Another object of the present invention is to use the drill hole expansion drill to form a reliable expansion base at the tip of the compression member such as a pile to improve the allowable bearing capacity of the pile, in the case of a tension member such as anchor reliability in the expansion It is to provide a method for constructing piles and tension members for construction workers that can significantly improve the pull-out resistance by forming a fixed fixing part.

Still another object of the present invention is to provide a construction method for constructing piles and tensile members for construction work which is excellent in economic efficiency and minimizes pollution to the underground environment while dramatically improving the allowable bearing capacity of the pile and the pulling resistance of the tension members in the construction work. have.

In accordance with the above object, the present invention, in the drilling diameter expansion drill used to expand the wall to a part of the drilling hole drilled in the ground for construction work, the hinges of the upper end is connected to the shaft portion of the rotating body and foldable sliding wings It is provided with a sliding wing assembly, each of the sliding blades is fixed to the cutting bit for the ball wall on the upper surface, characterized in that it comprises a movable member for controlling the lifting and folding of the sliding blade.

In addition, the sliding wing is characterized in that it has a length that can be expanded to the wall corresponding to 1.5 to 3 times the diameter of the drilled hole.

In addition, the sliding wing assembly is characterized in that it has a lifting angle range of 0 ° ~ 90 °.

In addition, the rotating body is rotatably installed at the tip of the connecting rod, the connecting rod, a concrete injection pipe for injecting the electric wire for controlling the driving of the drill hole expansion drill and the concrete in the dough state to the drill hole expansion drill side It is characterized by the configuration.

In addition, the drilling diameter expansion drill of the present invention, characterized in that it further comprises a rotating body drive unit for driving the rotating body, and a lifting and lowering drive unit for lifting the rotating body.

In one embodiment of the sliding wing assembly, the sliding wing is a rectangular plate and the left and right halves have a stepped structure, in which a hinge shaft piece is integrally formed at the center top of the left and right halves, and the cutting bits are arranged on the upper surface of the stairs at the left and right halves. Characterized in that the fastening is fixed.

In addition, the above-mentioned sliding wing assembly is a structure in which the sliding blades of the rectangular plate body are deviated from each other, and the cutting bits are configured to be fastened and fixed to the entire upper surface of the double-layered upper sliding blade.

In still another aspect of the sliding wing assembly, the cutting bits are arranged and fastened in a parallelogram zone in which each sliding wing is a trapezoidal plate and forms a stepped layer in the sliding wing.

In addition, the present invention, in the construction method pile construction method, after drilling the ground in the depth direction, the sliding blades having cutting bits are hinged to the rotating body and the sliding blades are drilled by the movable member drilling hole expansion drill hole A first step of positioning the tip portion, a second step of driving the drill hole expansion drill to expand the drill hole tip portion and simultaneously supporting the upper base of the expansion hole with the sliding blades of the drill hole expansion drill; The third step of filling the concrete through the drill hole expansion drill in the space of the end of the drilled hole in the expanded state, and gradually shrinks the drill hole expansion drill and at the same time the foundation concrete pouring into the space created by the shrinkage It is characterized by consisting of a fourth step of forming the enlarged base portion at the tip of the pile.

In addition, the present invention, in the construction method of the tension member for construction work, after drilling the ground in the depth direction, the sliding blades having cutting bits are hinged to the rotating body, the sliding blades are drilled by the movable member drilled drill diameter expansion drill A first step of positioning the hole at a tip end, a second step of driving the drill hole expansion drill to expand the drill hole tip and supporting the upper base plate of the expansion hole with the sliding blades of the drill hole expansion drill; The third step of passing the fixed fixing concrete through the drill hole expansion drill to fill the space of the tip of the drilled hole in the expanded state, and gradually shrinking the drill hole expansion drill and fixed fixation in the space created by the reduction. It is characterized by consisting of a fourth step of forming a fixed fixing part for the pull-out resistance at the tip of the tension member by filling with concrete for casting.

The drill diameter expansion drill of the present invention has the advantage of allowing the expansion to the desired drilling hole specifications while maintaining the shape of the expansion space without collapse of the upper ground of the expansion portion while expanding the tip portion or some section of the drill hole previously drilled in the ground have.

In addition, when the drill diameter expansion drill of the present invention is used, it is possible to form a reliable structure (for example, reinforced concrete expansion foundation) having a certain strength and specification at a desired position in the ground. It is possible to improve the tip bearing capacity and design the pile to receive compressive and tensile force at the same time.In the case of anchor, the tension member, the fixed fixing part is enlarged in the tip part, so it is not frictional force in the drilled hole. The ground shear resistance for the entire height of the upper soil layer around the outer diameter of the study can be expected to be a resistance to the draw, thereby significantly improving the pull resistance.

1 is a view for explaining the problem caused by the expansion of the end of the drilling hole previously drilled in the ground without a separate hollow wall holding device;

Figure 2 is a state of completing the pile construction for supporting the general structure foundation

3 is a state of completing the anchor construction for preventing buoyancy of a typical building,

4a and 4b is a cross-sectional view of the drill diameter expansion drill, according to an embodiment of the present invention;

5a and 5b is a cross-sectional view of the drill diameter expansion drill according to another embodiment of the present invention,

6a and 6b is a state cross-sectional view of the modified example in the drill bore expansion drill according to an embodiment of the present invention,

7a and 7b is a state cross-sectional view of the modified example in the drill bore expansion drill according to another embodiment of the present invention,

8 is a perspective view showing a state in which the sliding blades are fastened and unfolded by fastening the cutting bit according to the present invention;

9 is an exploded perspective view of some of the sliding wings hinged to the shaft portion according to the invention,

10 is a plan view of the sliding wing assembly with the sliding wings of FIGS. 8 and 9 spread out;

11 and 12 are a plan view showing a modified example of the sliding wing assembly with the sliding wings unfolded,

Figure 13 is a state diagram used in drilling drill expansion according to another embodiment of the present invention,

14 is a schematic view for explaining a construction procedure for forming an enlarged foundation at the tip of the pile using the drill diameter expansion drill of the present invention,

15 is a schematic view illustrating a construction procedure for forming a fixed fixing part of the tension pile in the tension member by using the drill diameter expansion drill of the present invention,

16 is a schematic diagram illustrating a construction procedure for forming a fixed fixing part of an anchor in a tension member by using the drill diameter expansion drill of the present invention;

17 is an enlarged cross-sectional view of forming a fixed base of an enlarged base portion of a compression pile tip or a tension member by injecting concrete into a hole wall expansion portion with a drill diameter expansion drill according to the present invention;

18 to 20 is a view showing applied to the example of the construction as a buoyancy preventing anchor that can form a variety of shapes and the number of expansion wall in the pre-drilled hole in the ground according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is to implement a drill that can be expanded in the drill hole standard while maintaining the shape of the expansion space without collapsing the upper ground of the expansion portion during the expansion of the tip portion or some section of the drill hole previously drilled in the ground.

Representative examples of the expansion of the tip or part of the perforated hole in the construction field in the construction field include pile construction for supporting the foundation of the structure, anchor construction for slope stability, anchor construction for preventing buoyancy of the building, Anchor construction for earthquake temporary installation, permanent anchor retaining wall construction, anchorage construction of suspension bridges and cable-stayed bridges, and anchorage construction of offshore structures.

The pile construction for supporting the foundation of the structure is for forming an enlarged foundation at the tip of the pile, as in the example shown in FIG. 2, and is mainly applied to a compressed pile. Of the various compression piles shown in Figure 2 (a) of Figure 2 is a construction state diagram constructed with a steel pipe pile (2), Figure 2 (b) is a PHC (Pretensioned spun High-strength Concrete) pile (4) 2 is a construction state diagram of the construction, and FIG. 2 (c) is a construction state diagram of the construction of the cast-in-place pile 6. And (d) of FIG. 2 is a construction state diagram constructed with a single pile 7 in which the foundation and the pillar are integrated.

In addition, anchor construction for slope stability, anchor construction for preventing buoyancy of buildings, anchor construction for retaining wall construction, permanent anchor retaining wall construction, anchorage construction of suspension bridges and cable-stayed bridges, etc. are used to form fixed fixing parts at the ends of tension members.

3 shows that the fixing unit 22 is formed through the expansion unit at the tip of the anchor 12 to stabilize the buoyancy of the building 14 as a representative example for forming the fixing unit at the tip of the tension member. have. The tension member mentioned here is a tension member used in construction work, such as tension piles and various anchors, that is, anchors for preventing buoyancy of buildings, anchors for slope stability, anchors for temporary wall anchors, anchors for permanent anchor retaining walls, Oil nails and the like. Examples of the material of the anchor of the tension member is a rebar, steel wire, steel bar, steel pipe, FRP tensile material, special fibers and the like.

In the case of anchor construction, the pullout resistance to the area represented by the product of the perimeter of the anchor 12 and the perforated length can be expected.

In the present invention is applied to the construction of the above examples, while expanding the tip or part of the drilled hole pre-drilled in the ground while maintaining the shape of the expansion space without the collapse of the upper ground of the expansion hole drill capable of expansion of the hole standard Implement

Figures 4a and 4b is a cross-sectional view of a drill diameter expansion drill according to an embodiment of the present invention, Figures 5a and 5b is a cross-sectional view of a drill diameter expansion drill according to another embodiment of the present invention.

And, Figure 6a and 6b is a state cross-sectional view of the modified state in the drill hole expansion drill according to an embodiment of the present invention, Figures 7a and 7b is modified in the drill hole expansion drill according to another embodiment of the present invention State sectional drawing of an example.

Drill hole diameter drill 30 according to the embodiments of the present invention shown in Figures 4a to 7b is common to the cutting bits 44 and the sliding blades 54 to which the cutting bits 44 are coupled for cutting the wall Equipped. The sliding blades 54 serve to support the upper base so that there is no collapse of the upper base due to the expansion of the hollow wall with the cutting bit 44 when the part of the drilling hole 24 is expanded.

Each of the sliding blades 54 according to the present invention is radially directed to the shaft portion 46 installed axially rotatable in the injection tube 40 or the tubular connector 34, and the upper end portion thereof is hinged. The sliding wings 54 constitute a sliding wing assembly 55 superimposed in a mutually folded form to form a tightly unfolded support surface like a cosmos petal arrangement when the sliding wings 54 are fully unfolded. Therefore, it is possible to safely support the upper base plate of the expansion part.

The sliding blades 54 having the cutting bits 44 fastened to the upper surface thereof have a length enough to expand 1.5 to 3 times the diameter of the drilling hole 24, preferably 1.5 to 2.5 times, and the sliding blades 54 It is preferable that the lifting angle range of the sliding wing assembly 55 of 0) is 0 ° to 90 °.

In defining the length of the sliding wing 54 in the drill diameter expansion drill 30 of the present invention as described above, the expansion portion for forming the expansion foundation of the pile or the fixed anchoring portion of the anchor that meets the specifications previously designed in the present invention It is unnecessary to make more than three times the diameter of the drilling hole 24 to prepare, and the expansion of less than 1.5 times the diameter of the drilling hole 24 is necessary for the expansion base of the pile or the fixing fixing part of the anchor to play a role. It's not enough.

In addition, the present invention is provided with a movable member to allow the sliding wing assembly 55 hinged to the shaft portion 46 as described above to expand or collapse. The movable member will be described with reference to FIGS. 4A to 7B, which is an example of the expansion balloon 42 which can be expanded and contracted by external fluid control (refer to FIGS. 4A, B, 5A, and B).

Another example of the movable member includes a vertically moving actuator 96 driven by external power transmission of one of pneumatic, hydraulic, and electric, and a connecting arm 43 connected to the rear surface of the actuator 96 and the sliding blade 54. ) May be implemented (FIGS. 6A, B, and 7A, B).

The main body of the drill diameter expansion drill 30 of the present invention is rotatably mounted on the tip of the tubular connecting table 34 inserted into the drilling hole 24. The tubular connector 34 is preferably a rigid tube such as a metal material, and preferably can be used as the axis of the drill diameter expansion drill 30. The rear end of the tubular connector 34 connected to the drill diameter expansion drill 30 extends to the ground through the drill hole 24. In addition, the tubular connector 34 is preferably provided with a support (not shown) at regular intervals on the cylindrical cylindrical surface so that the connector 34 can be stably supported in the drilling hole 24. The support can be implemented in a structure that can be push-pull operation as needed.

4A, 4B and 5A, 5B, the connecting rod 34 includes a pressure hose 36 and a drill hole expansion drill 30 for transmitting a pressure of a fluid A such as air to the inside of the tube. An electric wire 38 for controlling various kinds of drills such as axial rotational power transmission or lifting and lowering, and an injection tube 40 for injecting solid concrete (C) or concrete for fixing and fixing (C), The cooling water injection pipe 41 into which the cooling water W which cools the drill bit 44 is provided is provided. Cooling water inlet pipe 41 is an option that is installed as needed.

6A, 6B, 7A, and 7B, the external power of one of pneumatic, hydraulic, and electric for driving the actuator 96 instead of the pressure hose 36 of FIGS. 4A, 4B, 5A, and 5B. A power supply path 98 for transmitting the power is provided in the tubular connector 34.

The drill diameter expansion drill 30 shown in Figs. 4A to 5B is used to drill the hollow wall of the tip portion 26 of the drilling hole 24 or the other part of the drilling hole 24 while the drill itself performs both expansion and synergy. Cutting to expand.

4A and 4B, the drill hole expansion drill 30 according to the embodiment of the present invention shown in FIG. 4B is connected to the drill hole expansion drill 30 by pulling the drill hole expansion drill 30 from the ground. ) Is a way of raising, and in another embodiment of the present invention shown in Figures 5a, 5b is a method of raising the drill diameter expansion drill 30 by the lifting drive unit 56 installed in the expansion drill 30 itself. .

Drill hole expansion drill 30 of the present invention, the rotary body 50 to rotate the tip end of the connecting table 34 to the axis and equipped with the cutting bits 44, and the rotating body drive unit for driving the rotating body 50 52 is provided in common, and in the case of another embodiment of the present invention illustrated in FIGS. 5A and 5B, the elevator driver 56 includes an elevator driver 56 for elevating and rotating the rotor 50.

4A and 4B, the rotor 50 is rotatably coupled to the inner diameter of the tubular connector 34 via the shaft bearing B and has a shaft portion 46 protruding downward, and the shaft portion ( 46) is circumferentially circumferentially along the cylindrical outer surface of the shaft portion 46 together with the bulging balun 42 coupled to or wrapped around the outer surface of the shaft portion 46, or coupled or located at the lower end of the shaft portion 46 As the circumference of the flower tufts, the plurality of sliding wings (54) are enclosed and hinged at the same time supported by the contraction balun (42) by the expansion and contraction action of the contraction balun (42) as shown in Figure 4b Raise or straighten up or down as shown in Figure 4a has a folding structure.

The expansion and contraction balloon 42 may be expanded and contracted by the fluid pressure introduced through the pressure hose 36 embedded in the connection table 34. The outer wall of each of the sliding blades 54 may have an empty wall of the drilled hole 24. A plurality of cutting bits 44 for cutting and expanding are fastened.

4A and 4B, the concrete injection pipe 40 embedded in the connecting rod 34 is configured to pass through the inside of the shaft portion 46 and extend downward to form the concrete discharge hole 40a in the lower direction. Therefore, the concrete that is injected from the outside is discharged to the downward drilling hole 30 through the injection pipe 40.

Rotating body drive unit 52 for driving the rotating body 50 as described above is provided with one or two drive motors (M) fixed in the tubular body of the connecting table (34). The drive motor (M) is preferably a reduction motor in which reduction gears are installed in the motor body, and may be implemented as an electric motor or a hydraulic motor.

Since the drive shaft gear 82 fixed to the shaft of the drive motor M is engaged with the ring gear 84 fixedly installed in the tube body of the shaft portion 46, the rotor 50 is rotated by the rotation of the drive motor M. The shaft portion 46 of can rotate.

On the other hand, as shown in Figure 5a, 5b, the rotating body 50 is provided with a lower support 49, the lower portion of the tubular connector 34 to support the bottom of the perforated hole tip portion (26). Concrete discharge port (40a) is formed in the lower left and right sides of the tubular connector (34) in communication with the inlet tube 40 is injected through the concrete inlet tube 40 in the connector (34) Through the concrete discharge port 40a on the left and right sides of the lower end of the tubular connector 34 is discharged downward of the drilling diameter expansion drill (30).

5A and 5B, the drilling diameter expansion drill 30 shown in FIG. 5A may be moved up and down by the lifting and driving unit 56 provided with the rotating body 50. That is, the lower base 49 of the connecting table 34 supporting the bottom of the hole hole tip 26 is moved up and down by only the rotating body 50 while being supported by the bottom of the hole hole tip 26.

5A and 5B, the rotating body driving unit 52 driving the rotating body 50 to be rotatable includes one or two driving motors M that can be lifted and lowered in the tubular body of the connecting table 34. In other words, the tubular body of the connecting table 34 is formed with a slot that is long and vertically cut and the support rod of the driving motor M is fixed to the circular rail orbit member 88 which provides a rail when the rotating body 50 rotates. When the rotating body 50 moves up and down, the driving motor M moves up and down along the slot of the connecting table 34. 4A and 4B, the drive motor M is preferably a reduction motor, and may be implemented as an electric motor or a hydraulic motor.

5A and 5B, the shaft portion 46 is rotatably coupled to the outer circumferential surface of the connecting table 34 through the shaft bearing B and configured to protrude downward. In addition, a plurality of sliding wings 54 are hingedly connected to the shaft portion 46 along the circumference of the cylindrical outer surface of the shaft portion 46 together with the swelling balun 42 coupled to the lower end of the shaft portion 46 as if surrounded by cosmos leaves. At the same time, it is supported by the squeezing balun 42, and by the expansion and contraction action of the squeezing balun 42, the sliding wings 54 are raised as shown in FIG. 5B or stretched as shown in FIG. 5A.

5A and 5B, similarly to FIGS. 4A and 4B, the expansion balun 42 may be expanded and contracted by the fluid pressure introduced through the pressure hose 36 embedded in the connecting rod 34. A plurality of cutting bits 44 are fastened and fixed to the outer surface of the blade 54 to cut and expand the hollow wall of the drilling hole 24.

5A and 5B, the elevating driving unit 56 for elevating the rotating body 50 has the rotating body 50 with the lower support 49 of the connecting table 34 fixed to the bottom of the hole 26. ) As an actuator for moving up and down, the engaging slider 86 formed on the upper end of the shaft portion 46 is caught by the circular rail track member 88 and configured to slide along the rail track, the circular rail track member It can be configured that the 88 is connected to the operating rod (90a) of the operating cylinder 90 is linked to the connecting table (34).

The lifting drive 56 is preferably protected by covering with a bellows cover 92 as shown in the example shown in Figure 5a, 5b so that foreign matters such as soil from the outside, it is adopted in the lifting drive 56 The actuated cylinder 90 can be implemented pneumatically or hydraulically.

In addition, the lifting drive unit 56 that pulls up or pushes down the rotating body 50 has been described as an example of an operation cylinder structure, but the rack structure and the pinion structure of the gear structure, the actuator structure, or the like may be embodied in this technique. It will be apparent to those of ordinary skill in the art.

In more detail with respect to the drill diameter expansion drill 30 of the present invention, the drill diameter expansion drill 30 of the present invention is commonly provided with a rotating body 50 that rotates around the connecting table 34 as an axis. . In addition, the expansion balun 42, which is one of the components of the rotor 50, cuts and expands the drilled hole tip portion 26 while the sliding blade 54 having the cutting bits 44 is gradually extended with rotation. It serves to push the sliding wing 54 to support the upper base of the expansion portion 24a. In addition, when the expansion of the concrete (C) into the expansion portion (24a) also serves to fold back the spreading wing (54).

The squeezed balun 42 is formed to have wrinkles and bulky properties so that a special reinforcing fiber such as aramid fiber yarn used in a parachute or body armor can be stretched in a radial direction, and a rubber layer capable of elastic swelling is bonded in the reinforcing fiber layer. Consists of the formed composite material.

The expansion balloon 42 is generally donut-shaped in an expanded state, and has a concentric direction (or circumferential direction) to allow the injection of a fluid A such as air into the shaft portion 46 coupled to one surface of the expansion balloon 42. A rail groove is formed along the injection hole 59 in the bottom surface of the rail groove. The pressure hose 36 is hermetically inserted into the concentric rail groove of the shaft portion 46 and is connected in communication with the circular air room portion 58 fixed to the injection pipe 40 or the connecting table 34. Therefore, compressed air, which is the fluid A injected through the pressure hose 36, is injected into the expansion balun 42 through the injection hole 59 formed in the bottom of the concentric rail groove of the circular airroom 58 and the shaft 46. Can be.

When the volume of the expansion balloon 42 is expanded by a fluid injection such as air, the diameter may be increased to 2 to 3 times the initial diameter of the drill which is reduced in volume. The pressure applied to the expansion balloon 42 is preferably 7 to 25 kgf / cm 2, and at this time, the force that can be supported on the upper surface of the dilating portion 24a of the hole hole tip 26 is expanded when the diameter 600 mm is 1000 mm. More than 30 tons. The support force of the swelling balun 42 is to support a loose ground weight of less than 1 ton that the base plate on the upper portion of the expansion portion 24a of the drilling hole tip portion 26 is relaxed.

The squeezed balun 42 is reduced in volume as the fluid, such as compressed air, is drawn out, ie, reduces the fluid pressure, and preferably can be reduced to almost the diameter of the connecting rod 34.

In addition, in the present invention, the cutting bits 44 for cutting and expanding the hollow walls of the drilling holes 24 are made of a high strength special steel material, and are mounted on the outer surface of the sliding wing 54. It is preferable to be prefabricated to be replaceable when mounted on the outer surface of the sliding wing 54, such assembly is facilitated when the cutting bit 44 is worn.

According to the present invention, each of the sliding blades 54 having the cutting bits 44 fastened to the outer surface thereof is hinged to the cylindrical outer circumferential surface of the shaft portion 46 so as to be radially unfolded or folded. The lifting angle range of the sliding wing assembly 55 made of the sliding blades 54 is preferably 0 ° to 90 °.

Meanwhile, in FIGS. 6A, 6B, 7A, and 7B, the sliding blades 54 may be replaced with the expansion balloon 54 that pushes up or pulls down the sliding blades 54 in FIGS. 4A, 4B, 5A, and 5B. On the back of the) one end is connected to the connecting arm 43 is connected.

The other end of the connecting arms 43 is connected to the actuator 96 that moves up and down in the outer circumferential wall of the flange pipe 94 rotatably mounted on the concrete injection pipe 40 or the connecting table 34. Actuator 96 may be implemented by pneumatic, hydraulic, electric or the like.

Figures 6a and 6b shows a state cross-sectional view of a modified example of the drilling diameter expansion drill of Figures 4a, 4b according to an embodiment of the present invention, Figures 7a and 7b according to another embodiment of the present invention Figure 5a, Figure 5b shows a state cross-sectional view of the modified example in the drill bore expansion drill.

In FIGS. 6A to 7B, the connecting arm 43, the flange tube 94, and the actuator 96 are provided in place of the expansion balloon 42, and the reference numeral 98 in FIGS. 6A to 7B denotes an actuator ( 94 is a power supply path for supplying external power. If actuator 96 is implemented pneumatically or hydraulically, power supply path 98 will be a compressed air engine or hydraulic tube, and if actuator 96 is implemented electrically, power supply path 98 will be an electrical line. .

8 is a perspective view illustrating a state in which the sliding blades 54 having a foldable structure are folded and unfolded while fastening the cutting bit 44 to an upper surface thereof according to the present invention, and FIG. 9 is hinged to the shaft portion 46. A partially exploded perspective view of the sliding blade 54.

The sliding blade 54 shown in FIG. 8 and FIG. 9 is a rectangular plate-like structure, and the left and right half halves have a stepped structure, and the hinge shaft piece 54c is integrally formed in the upper center of the left and

right halves

54a and 54b. Cutting bits 44 are arranged on the surface of the upper and lower stairs 54a of the left and right halves, and the cutting bits 44 are arranged in a fastening structure, and the lower stairs 54a are smoothly overlapped with the bottom of the upper stairs 54a of the adjacent sliding wing 54. Has a tangent

The sliding wing assembly 55 assembled with the sliding blades 54 having the above structure is folded down by the sliding blades 54 so that the lower step portion 54b of the sliding blade 54 and the sliding blade 54 adjacent thereto are provided. The staircase layer portion 54a is completely superimposed so that it can be erected almost parallel with the axis of the shaft portion 46. On the other hand, when the sliding blades 54 are pushed up, the stepped upper layer portion 54a of the sliding blade 54 having the sliding blades 54 on the upper surface thereof is unfolded as if the fan blades were unfolded.

FIG. 10 shows a plan view of the sliding wing assembly 55 in which the sliding wings 54 shown in FIGS. 8 and 9 have their wings spread.

11 and 12 are plan views showing modified examples of the sliding wing assembly 55 with the sliding wing 54 extended.

The sliding wing assembly 55 shown in FIG. 11 has a double-folded structure in which the sliding wings 54 are shifted from each other, and the sliding wing 54 is a rectangular plate and the upper-level sliding wing 54 among the double-winged sliding wings 54. The cutting bit 44 is fastened and fixed to the entire upper surface of -1). The upper surface of the double lower sliding wing (54-2) can be implemented without the installation of the cutting bit 44, as shown in Figure 11, if necessary, the cutting bit in the form of a triangular zone (zone) at the end of the upper surface of the wing ( 44 may also be fastened and fixed.

In the structure of the sliding wing assembly 55 as shown in Figure 11, when the sliding blade 54 is fully extended, cutting bits 44 are formed on the entire surface of the unfolded wings, thereby improving cutting efficiency of the hollow wall.

Next, the sliding wing assembly 55 illustrated in FIG. 12 is a stepped trapezoidal rectangular plate body in which cutting bits 44 are arranged in the parallelogram zone forming the stepped upper layer part 54a to form a stepped lower layer part 54b. The remaining triangular zone has a smooth contact surface that can overlap the bottom surface of the stepped layer portion 54a of the adjacent sliding wing 54.

FIG. 13 is a diagram illustrating a state of use of the drill diameter expansion drill 30 according to the present invention, in which a sliding wing assembly 55 having sliding wings 54 as shown in FIGS. 8 to 12 is hinged to the shaft portion 46. The lower support 49 of the connector 34 is provided with the lower support 49 extending from the shaft portion 46 to support the bottom of the drilled hole tip 26. The hollow wall is cut and extended by moving only the rotating body 50 while being supported at the bottom of the base, and is discharged from the concrete discharge port 40a formed in the connecting table 34 in the space portion under the rotating body 50 which is empty by cutting. The concrete will be filled immediately.

Figure 14 is a schematic view for explaining the construction procedure for the expansion foundation formed on the tip of the pile using the drill diameter expansion drill of the present invention, Figure 15 is a fixed anchoring portion of the tension pile using the drill diameter expansion drill of the present invention Figure 16 is a schematic diagram illustrating a construction procedure for forming, Figure 16 is a schematic diagram illustrating a construction procedure for forming a fixed fixing portion of the anchor using the drill diameter expansion drill of the present invention.

First, with reference to Figure 14 will be described in detail the construction procedure for forming an enlarged foundation to meet the pre-designed specifications on the pile tip using the drill diameter expansion drill 30 of the present invention.

First, as shown in FIG. 14A, the ground is drilled and the tubular casing 32 is installed in the drilling hole 24.

The ground is drilled in the depth direction using a hammer drill or the like, and a perforated hole 24 is formed by drilling a solid soil layer in the ground or a rock layer 8 if necessary. In this case, the depth direction of the ground is mostly the vertical direction of the ground and may also include the inclination direction, the depth of the drilling hole 24 is usually formed from several meters to several tens of meters.

The tubular casing 32 is installed in the boring hole 24 to form the boring hole 24 and to prevent the collapsing of the boring hole 24. A representative example of the tubular casing 32 is a steel pipe casing. The tubular casing 32 is installed in a stratum section in which a perforated wall may collapse, such as a sand layer, a gravel layer, or a weak soil layer, and the installation may be omitted when the ground layer is hard.

Next, as shown in FIG. 14B, the drill diameter expansion drill 30 is positioned at the tip portion 26 of the drill hole 24.

When the drill diameter expansion drill 30 is operated, the rotating body 50 of the drill diameter expansion drill 30 rotates. Accordingly, the cavity 24 of the hole hole tip 26 is cut by the cutting bits 44 fastened and fixed to the sliding blades 54 of the rotating body 50 to start the formation of the expansion portion 24a. At the same time, the sliding blades 54 of the drill dilator 30 are gradually expanded by the operation of a movable member (such as an expansion balloon or a connecting arm linked to an actuator) to form a dilator 24a properly, The upper base does not collapse because it supports the upper part of the dilator. That is, the periphery of the perforated hole tip portion 26 can be prevented from collapsing during the expansion by the drill diameter expansion drill 30.

At this time, the concrete for the solid state of the dough (60) through the concrete injection pipe 40 and the lower discharge hole (40a) of the drilling diameter expansion drill 30 in the connecting shaft 34 installed in the drilling diameter expansion drill (30) It is immediately discharged and filled in the space of the perforated hole tip portion 26 in the expanded state, that is, the expanded portion 24a, as shown in FIG.

In addition, it is preferable that the drilling diameter expansion drill 30 moves upward to provide the expansion portion 24a as necessary to form an expansion base portion conforming to a previously designed standard simultaneously with rotation. By the upward movement of the drilling diameter expansion drill 30, the upper surface of the sliding blades 54 is always supported to support the base of the upper portion of the expansion portion 24a, thereby preventing the base wall wall from collapsing, while expanding the empty portion. The left and right widths and thicknesses (height) of the enlarged foundation to be poured on 24a can be sufficiently secured.

In addition, the foundation concrete 60 is continuously injected into the expansion portion 24a, and thus, the expansion of the foundation concrete 60 and the injection of the foundation concrete 60 are sufficiently made. Then, the size of the drill diameter expansion drill 30 is reduced to the initial state by controlling the movable member and folding down the sliding blade 54 as shown in FIG. Expansion to support the pile tip by continuously filling the foundation concrete 60 in the space created by the volume reduction of the drill diameter expansion drill 30 as the sliding blades 54 of the drill diameter expansion drill 30 are completely folded. The base portion 62 is formed as shown in Fig. 14F.

When the foundation concrete 60 is injected into the expansion portion 24a of the drilling hole tip portion 26 through the discharge hole 40a penetrating downward through the drilling diameter expansion drill 30 (FIG. 14 (d) (e)) ), It is to be understood that the liquid stabilizer 64 is injected when necessary to prevent the collapsing of the punching hole 24 outside the connecting rod 34 inserted into the punching hole 24. The liquid stabilizer 64 has a specific gravity lower than that of the foundation concrete 60.

As shown in FIG. 14F, when the volume-reduced drill diameter expansion drill 30 is removed from the drill hole 24 and recovered to the ground, the casting of the foundation concrete 60 is completed. Completion of the casting of the foundation concrete 60 means that the formation of the enlarged foundation 62 of the pile tip that meets the previously designed specifications is completed. As shown in FIG. 14 (f), when the casting of the foundation concrete 60 is completed, the liquid stabilizer 64 is pushed up by the foundation concrete 60 because the specific gravity is lower than that of the foundation concrete 60. .

After recovering the drill diameter expansion drill 30, the compression pile 66 is entered into the drilling hole 24 as shown in (g) of FIG. 14 and the tubular casing 32 is also removed. At this time, in the example of the present invention so that the tip end portion of the compression pile 66 can be left on the enlarged base portion 62 placed in the expansion space of the drilling hole tip portion 26 as shown in Fig. 14 (g) The spacer 66a is attached to the lower end of the 66. In addition, as another example of the present invention, the tip end portion of the compression pile 66 can be left on the enlarged base portion 62 placed in the expansion space of the drill hole tip portion 26 as shown in FIG. The head 66 is formed to have a stopper 66b. The stopper 66b mounted on the head of the pile 66 is hooked to the ground floor to allow the compression pile 66 to rest on the enlarged base portion 62 meeting the previously designed specification.

In addition, in forming the enlarged foundation portion 62 of the compression pile 66, a reinforcing structure fastened to the tip of the pile may be provided in the foundation concrete 60 which is not hardened if necessary. In this case, it is preferable to use a vibrator for concrete for smooth insertion of the reinforcement structure.

Next, FIG. 15 and FIG. 16 illustrate a construction procedure for forming a fixed fixing part for drawing resistance of a tension member by using the drill diameter expansion drill 30 of the present invention.

Figure 15 relates to the construction of the tension pile 70, Figure 16 is anchor 80 construction, for example, anchor construction for preventing buoyancy of the building, anchor construction for slope stability, anchor construction for retaining wall, permanent anchor retaining wall anchor It is about construction, suspension bridge and cable-stayed bridge anchorage construction.

The construction of the tension pile 70 of FIG. 15 is almost similar to the construction method of the compression pile 66 shown in FIG. 14, and finally, in FIG. 15 (g), the fixing fixing part 74 for drawing resistance is expanded. It is different from that of Fig. 14G of the compression pile construction method that is formed at the tip end. In the fixed fixing part 74 for drawing resistance, a reinforcing structure 72 capable of resisting a load such as a pulling force acting on the tension member during common use must be installed in the fixed fixing concrete 60. In this case, the concrete 60 in which the reinforcing structure 72 is installed, such as reinforcing steel reinforcing bar, FRP (Fiberglass Reinforced Plastics) reinforcing material or reinforcing steel plate, is used for fixing and fixing. Reinforcing bars used as the reinforcing structure 72 may be like an umbrella rod folded when it is inserted into the drilling hole 24 and then radially unfolded from the fixed fixing part 74 to be embedded in the concrete 60. The longitudinal reinforcing bars of the reinforcing structure 72 may be used as spacers 66a for fixing the tension piles 70 on the fixed fixing part 74 as shown in FIG. 15, and do not use the longitudinal reinforcing bars as spacers. In the case of forming it short, a stopper 66b may be mounted on the head of the tension pile 70 for fixing the tension pile 70. The reinforcing bar of the reinforcing structure 72 may be replaced with another material capable of resisting the working load such as the pulling force in the fixed mounting portion (74).

The anchor construction shown in FIG. 16 is replaced by the anchor 80 instead of the tension pile 70 as a tension member, and a specific construction method is almost similar to that of the tension pile 70 of FIG. 15 as shown in FIG. . Therefore, detailed description thereof will be omitted.

17 is a hole diameter expansion drill according to the present invention, and preferably, a part of the hole is preferably formed in the hole wall extension portion at the end of the hole hole, and the concrete is injected into the hole wall extension portion to expand the base or tension member, that is the tension of the tip of the compression pile An enlarged cross-sectional view showing the fixing fixture of a pile or an anchor is shown.

17 (a) is a cross-sectional state diagram in which an enlarged foundation 62 is applied to the tip of the compression pile 66 to support the foundation foundation, and FIG. 17 (b) shows the tension pile 70 according to the present invention. It is a cross-sectional state figure in which the fixed fixing part 74 for drawing resistance was applied to the front end.

However, in forming the enlarged foundation portion 62 at the tip of the compression pile 66 to support the foundation of the structure, it may be applied as a rootless enlarged foundation as shown in FIG. 17 (a), and in FIG. 17 (b). It should be understood that the reinforcing structure 72 may be installed in the concrete 60 of the fixed fixing part 74 enlarged as described above.

18 to 20 show the application of the buoyancy preventing anchor 80 of the building 14 to form an example of the expansion wall having various shapes and numbers in the drilled hole pre-drilled in the ground according to the present invention. Drawing.

In the present invention, the expansion wall at the end of the drilling hole is formed properly to meet the specifications designed in advance to the fixed anchoring portion 74 for drawing resistance having the reinforcing structure 72 or the expansion foundation of the compression pile end, the hollow wall expansion portion As illustrated in 18, it may be formed in a cylindrical shape or a cylindrical shape and a cone in the upper portion, as shown in Figure 19 may be formed in two or more appropriate numbers. In addition, as illustrated in FIG. 20, it is possible to form a multistage hollow wall extension having a different diameter of the hollow wall extension.

As described above, by using the drill diameter expansion drill 30 as described above, the hole wall may be extended to a portion of the drill hole, preferably the tip portion of the drill hole, and the concrete 60 injection and / or reinforcement structure 72 may be installed. 62) or when the fixing fixing part 74 for drawing resistance is formed, the following effects are obtained.

First, in the case of compressed piles, a kind of enlarged foundation is formed at the tip of the pile by the expansion of the end of the drilling hole (to secure enough ground area so that the pile body surrenders exceeding the allowable load in terms of material, so the bearing capacity or settlement of the ground It is possible to reduce the number of used piles by greatly improving the allowable bearing capacity of the piles, and if necessary, it is possible to construct the pile tip up to the level of solid soil layers, not weathered rocks or soft rocks. .

Second, in case of tension pile, the shear resistance of the ground can be expected as much as the total length of the periphery of the expansion hole by expanding the end of the perforation hole, so that the pull-out resistance of the tension pile is remarkably improved. By introducing the concept, the basic standard and the number of pile heads can be greatly reduced, and it can be applied particularly effectively to piles that need to be subjected to both tension and compression.

Third, even in the case of anchor construction to prevent buoyancy, it is possible to utilize the enlarged shear resistance and self-weight of the periphery of the entire drilling length by expanding the end of the drilling hole, thereby reducing the length of the fabric mill and anchor, and the minimum anchor body and The protection grout alone can greatly improve stability.

Fourth, in the case of anchor construction for slope stability, the enlarged shear resistance of the periphery of the entire drilling length by the expansion of the tip of the drilling hole (the ground shear resistance of the expansion part rather than the frictional force of the anchor length of the drilling hole is very Large pullout resistance can be secured), which can reduce the length of fabric factory and anchor, and greatly improve the stability with minimal anchor body and protective grout.

Fifth, even in the case of anchor construction for earthquake temporary installation, it is possible to utilize the enlarged shear resistance of the periphery of the entire drilling length by expanding the end of the drilling hole, thereby reducing the length of the fabric factory and anchor, and minimizing the anchor body and the protective grout. Only stability can be greatly improved.

Sixth, if it is necessary to minimize the foundation base such as the retaining wall of the site boundary, it is possible to easily secure the stability of the structure by applying the tension pile or tension anchor with the perforated end of the perforated hole in the foundation base, and even in the case of the permanent anchor retaining wall By applying the tension anchor with the extended end of the drill hole, the base plate is minimized to reduce the damage to the surrounding environment and economical construction is possible.

Seventh, in the case of anchorage construction to secure the overall stability of cable supporting bridges such as suspension bridges and cable-stayed bridges, it is possible to reduce the standard of cable anchoring blocks or directly anchor them to rock without anchor blocks, thereby reducing damage to the surrounding environment and economical construction. Do.

Eighth, economical construction is possible while minimizing damage to surrounding environment even for anchoring of piles, anchors and offshore facilities used in offshore structures.

Claims

In the drill bore expansion drill used to expand the hollow wall in a part of the drilled hole drilled in the ground for construction work,
The upper end is hinged to the shaft portion of the rotating body and provided with a sliding wing assembly made of a plurality of foldable wings, when the plurality of wings is unfolded, the upper support surface of the cosmos petal arrangement form at the same time the plurality of sliding wings at the same time Each of the cutting bits for cutting a plurality of hollow walls are fixed to the upper surface, and provided with a movable member for controlling the raising and lowering of the sliding blade, the lifting angle of the sliding blade is configured to be in the range of 0 ° ~ 90 ° Drill diameter expansion drill having a shape-maintaining function of underground expansion.
According to claim 1, The sliding blade is drill hole expansion drill having a shape maintaining function of the underground expansion, characterized in that having a length that can be expanded to the wall wall equivalent to 1.5 to 3 times the diameter of the drilling hole.
According to claim 1, The rotating body is rotatably mounted on the tip of the connecting rod,
The connecting rod has a shape maintaining function of the underground expansion part, characterized in that the concrete injection pipe for injecting the concrete in the kneaded state with the wire for controlling the driving of the drill hole expansion drill side built Drilling hole drill.
The method according to claim 1 or 3,
A rotating body driving unit for driving the rotating body;
Drill hole diameter expansion drill having a shape maintaining function of the underground expansion portion further characterized in that it further comprises an elevating drive unit for elevating the rotating body.
According to claim 1, wherein the sliding wing assembly has a sliding plate is a rectangular plate body and the left and right halves are formed in a step shape, the hinge shaft piece is integrally formed on the center upper end of the left and right halves and the cutting bits are arranged on the upper surface of the stairs of the left and right halves. Drill diameter expansion drill having a shape maintaining function of the underground expansion portion characterized in that the fastening is fixed.
The method according to claim 1, wherein the sliding wing assembly is a structure in which the sliding blades of the rectangular plate body deviated from each other, the shape maintaining the shape of the underground expansion portion, characterized in that the cutting bit is fastened and fixed to the entire upper surface of the double-layered upper sliding blade. Drill bore drill with function.
The method of claim 1, wherein the sliding wing assembly has a shape maintaining function of the earth expansion portion, characterized in that the cutting bit is arranged and fastened in the parallelogram zone where each sliding wing is a trapezoidal plate and forming a stepped layer in the sliding wing. Having drilled diameter drill.
According to claim 1 or 3, wherein the movable member is a drill bore expansion drill having a shape maintaining function of the underground expansion portion, characterized in that the expansion and contraction of the expansion fluid can be reduced by the external fluid control.
According to claim 1 or claim 3, wherein the movable member is characterized by consisting of an actuator that is moved up and down by the external power transmission of one of pneumatic, hydraulic, or electric, and a connecting arm linked to the back of the actuator and the sliding wing. Drill diameter expansion drill having a shape maintaining function of the underground expansion.
In the construction method of construction piles,
Perforated diameter that allows multiple sliding wings to be slid by movable members after the ground is drilled in the depth direction so that the multiple sliding blades each having multiple cutting bits are hinged to the rotor and unfolded. A first step of placing the extension drill at the tip of the hole;
A second step of supporting the upper base plate of the dilatation portion with a plurality of sliding blades of the bores dilation drill, in which a base portion of the cosmos petal arrangement is formed when the distal end portion of the drill hole is expanded while expanding the distal end portion of the drill hole;
A third step of filling the concrete for the foundation with the drilling diameter expansion drill and filling the space at the tip of the drilling hole in the expanded state;
A fourth step of gradually expanding the drill diameter expansion drill and simultaneously filling the space generated by the reduction with concrete concreting for the foundation to form an enlarged foundation portion that meets a previously designed specification at the tip of the pile;
Construction of a pile for construction workers using a drill diameter drill, comprising the fifth step of removing the drill drill from the drill hole and installing the reinforcement structure fastened to the pile tip together with the pile in the foundation concrete filled in the expansion hole. Way.
In the construction method of the tension member construction,
Perforated diameter that allows multiple sliding wings to be slid by movable members after the ground is drilled in the depth direction so that the multiple sliding blades each having multiple cutting bits are hinged to the rotor and unfolded. A first step of placing the extension drill at the tip of the hole;
A second step of supporting the upper base plate of the dilatation portion with a plurality of sliding blades of the bores dilation drill, in which a base of the cosmos petal arrangement is formed when the distal end of the drill hole is expanded by expanding the drill hole extension drill; ,
A third step of passing the fixed-seating concrete through the drill hole expansion drill to fill the space of the end of the drilled hole in the expanded state;
A fourth step of gradually reducing the boring diameter expansion drill and simultaneously filling the space generated by the reduction with concrete placement for fixing and fixing to form a pull-out fixing portion for drawing resistance at the tip of the tension member;
Tensile for construction workers using a drill-drill drill, characterized in that the fifth step of removing the drill-drill drill from the drill hole and installing a reinforcing structure fastened to the end of the anchor together with the anchor in the fixed fixing concrete filled in the expansion hole Member construction method.