WO2017204400A1

WO2017204400A1 - Method for constructing improved ground anchor, having extended fixed anchor length, by using extended boring and stirring device

Info

Publication number: WO2017204400A1
Application number: PCT/KR2016/007281
Authority: WO
Inventors: 김인철
Original assignee: (주)대안소일텍
Priority date: 2016-05-26
Filing date: 2016-07-06
Publication date: 2017-11-30
Also published as: CN108026709B; KR101777774B1; CN108026709A

Abstract

The present invention provides a method, of an improved ground anchor having an extended fixed anchor length, using an extended boring and stirring device, the method enhancing an effect of stirring a cement grout material in a fixed anchor length section, increasing the tensioned coupling performance of an anchor body by forming a high-quality cement root, and enabling the time for extended boring and stirring to be shortened.

Description

Construction method of expansion anchor type ground anchor using expansion excavation stirring device

The present invention relates to a method for constructing an anchorage expansion type ground anchor using an enlarged excavation stirring device, in particular, to enhance the agitation effect of cement grout material in the anchorage section, and to form a high-quality enlarged cement bulb to tighten the anchor body. The present invention relates to a method for constructing an anchorage expansion-type ground anchor using an enlarged excavation stirring device capable of shortening the construction time of enlarged excavation and stirring.

In general, when ground anchors need to be anchored in the ground (especially in soft ground with an N value less than 15), it is necessary to ensure a constant anchoring force (anchor bearing capacity) due to various factors occurring during drilling and injection. Due to the nature of the ground, there is a limit to the shear stress of the ground.

As a result, the number of anchors to be installed increases, resulting in an increase in construction costs and construction periods, as well as deterioration in construction quality due to the effects of anchoring forces between anchors and the construction of anchor holes in the drilling (flushing) process. The current situation is causing various problems such as dense horizontal gap of the ball), ground subsidence phenomenon caused by the drilling process of the drilling water and the excavation slime.

As a background technology of the present invention, Korean Laid-Open Patent Publication No. 10-2009-0094734 (soil surface stabilization method) has been proposed. This is a method of injecting cement grout material into the anchorage expansion hole by slowly pulling it up while rotating the drilling plant from the bottom to the anchorage hole, after drilling the expansion hole in the rotating drilling device as the arm expands by hydraulic pressure. Is done. In this case, there is a problem that the perturbation and settlement of the ground around the expansion hole are inevitable due to the drilling and slime laying by the drilled water.

Another technology that is the background of the present invention has been proposed Korean Patent Registration No. 10-1481123 (soft ground extension drilling device and soft ground reinforcement method using the same). The soft drilling extension drilling device used in this method adopts a method in which the refraction fixing blade is extended by the elastic member exerting elastic force by pulling the pull string from the ground and cutting the fixing band in the refraction fixing fixing blade fixing step. There is a disadvantage that the configuration is complicated.

The present invention is to expand the stirring effect of the cement grout material in the anchorage section, to form a high-quality enlarged cement bulb to increase the tension fastening performance of the anchor body, the expansion excavation stirring device that can shorten the construction time of expansion excavation and stirring The purpose of the present invention is to provide a method for constructing an anchorage enlarged ground anchor using an expansion method.

According to a preferred embodiment of the present invention, (a) an outcasing anchorage drilling step of carrying out a drilling operation by drawing outcasing to the tip of the anchorage section in the ground; (b) primary cement grout material injection step of injecting primary cement grout material into the anchorage section into the out casing; (c) an outcasing drawing step of drawing outcasing only up to the tip of the free field section and removing outcasing from the settling section; (d) After the expansion excitation stirring device connected to the inner rod is inserted into the outcasing, the expansion excavation stirring device is rotated and reciprocated in the anchorage section while spraying the secondary cement grout material from the expansion excavation stirring device to enlarge the excavation. Forming an enlarged cement bulb and simultaneously filling the slime into the inside of the outcasing with back pressure generated during stirring; (e) drawing up and removing the expansion rig stirring device and replenishing the cement grout material by replenishing the cement grout material by a small amount of slime released from the out casing; (f) inserting and positioning an anchor assembly having geotextiles (packs) or corrugated pipes at the distal end into the enlarged and stirred anchorage section; (g) an outcasing removing step of extracting the outcasing from the ground and removing it outwardly; And (h) forming an anchor bulb by injecting a tertiary cement grout material into the pack or corrugated pipe of the anchor assembly to form anchor bulbs.

In addition, in the steps (b) and (d), the primary cement grout material and the secondary cement grout material, respectively, are characterized in that the ratio of water-cement is 100% to 180%.

In addition, in the step (h), the tertiary cement grout material is characterized in that the water-cement ratio is 50% or less.

In addition, the expansion excavation stirring device, an inner rod adapter coupled to the inner rod through a screw connection of one end; A grout injection shaft coupled to the other end of the inner rod adapter and having a plurality of grouting injection holes positioned in a section between the fixed side hinge block and the movable side hinge block; An excavation head coupled to an end of the grout injection shaft; A fixed side hinge block inserted into the grout injection shaft and fixed to the other end of the inner rod adapter; A movable side hinge block movably inserted into the grout injection shaft; A stirring blade having one end rotatably hinged to the movable side hinge block; A stirring blade operating lever having one end hinged to the movable side hinge block and the other end hinged to the stirring blade; It is characterized in that it comprises a stirring blade expansion spring is inserted into the outer diameter portion of the grout injection shaft and disposed between the movable side hinge block and the excavation head to provide an expansion force to open the stirring blade.

In addition, the stirring blade is characterized in that arranged at intervals of 90 degrees around the shaft for grout injection.

In addition, the grout injection shaft is characterized in that the leaf spring is provided that provides the initial expansion force at the moment of exiting the out casing in the state that the stirring blade is folded.

In addition, when the stirring blade is rotated to extend the stirring angle stopper is installed between the fixed side hinge block and the movable side hinge block to be fixed to the grout injection shaft in order to limit the rotation angle within a certain installation is further installed. It is characterized by that.

In addition, the excavation head may include a head connection portion whose one end is screwed to the grout injection shaft; An excavation head portion formed conically in the other end of the head connection portion; A grouting injection passage extending from the head connection portion by a predetermined depth; An excavation bit attached to the conical surface of the excavation head portion at regular intervals; It is characterized in that it is produced by forming a plurality of head grooves that are formed concave at regular intervals in the excavation head portion at regular intervals to form a passage for the grout liquid to be sprayed smoothly to the stirring blade side.

In addition, the drilling head portion is characterized in that a plurality of grouting injection port is further formed.

According to the present invention, since the excavation is made while injecting the secondary cement grout material in the primary cement grout material portion filled in the anchorage section, the stirring effect is enhanced. In addition, when the tertiary cement grout material, which is filled and expanded inside the pack or the ERP corrugated pipe, is cured, a high quality cement bulb prevents the anchoring body from escaping from the anchor body, thereby improving tension fastening performance. In addition, expansion and excavation is performed in the primary cement grout material portion filled in the anchorage section than when expanding and fixing the base plate of the fixing unit, and thus the construction time can be greatly shortened.

In addition, the enlarged excavation stirring device applied in the present method is capable of automatically expanding the stirring blade mechanically by the stirring blade expansion spring without using a separate power, thereby eliminating the need for an electric power device and simplifying the configuration. Easy to manufacture and less trouble of failure.

The following drawings, which are attached in this specification, illustrate the preferred embodiments of the present invention, and together with the detailed description thereof, serve to further understand the technical spirit of the present invention. It should not be construed as limited.

1 to 8 is a process flow chart of the anchorage expansion improvement type ground anchor construction method using the expansion excavation stirring apparatus according to the present invention,

1 is a perforated state diagram of outcasing,

2 is a state diagram of filling the cement grout material in the anchorage section of the expansion excavation stirring device is inserted into the out casing,

3 is a state diagram in which the out casing is removed to the tip of the free field section,

4 is an enlarged excavation and agitation state diagram using an enlarged excavation stirring device,

Figure 5 is a state diagram to remove the expansion and excavation stirring apparatus inserted in the out casing,

FIG. 6 is a state diagram in which the anchor assembly is inserted into the outer casing and the pack is placed in the enlarged and stirred fixing section. FIG.

7 is a state in which the anchor assembly is inserted into the expanded excavated stirring layer,

8A is a state diagram in which the simmite grout material is injected and filled into the pack of the anchor assembly,

8B is a cross-sectional view taken along the line A-A of FIG. 8A,

9 is a perspective view according to an embodiment of the expansion excavation stirring apparatus applied to the construction method of the present invention,

10 is an exploded perspective view of FIG. 9,

FIG. 11 is a side view of FIG. 10 and is an expanded state of operation as soon as the stirring blade exits the outer casing.

12 is a cross-sectional view of FIG. 11,

Fig. 13 is a state diagram in which the stirring blades of the enlarged excavation stirring device are folded in the out casing.

In the following the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the embodiments presented are exemplary for a clear understanding of the present invention is not limited thereto.

1 to 8 show the process flow diagram of the anchorage expansion type improved ground anchor construction method using the expansion excavation stirring apparatus according to the present invention.

아웃케이싱 정착장까지 천공Drill out to the outer casing

First, as shown in FIG. 1, the drilling operation is performed while drawing the outcasing 7 to the tip of the anchorage section S2 of the ground 1. The drilling operation may be performed by, for example, pressurizing water into the inside of the outcasing 7. As such, by drilling out to the tip of the anchorage section (S2) using the out casing (7), the amount of work included in the excavation area is relatively small during the enlarged excavation process to be described later, the excavation load is reduced to improve the work speed and expand excavation This becomes easy.

1차 시멘트 그라우트재의 주입Injection of primary cement grout

Next, as shown in FIG. 2, the primary cement grout material 1a is injected into the fixing unit section S2 into the out casing 7.

At this time, the cement grout material to be injected is preferably made of a water-cement ratio of 100% to 180% by weight. The water-cement ratio is approaching 100% in soft ground and 180% in non-soft ground.

아웃케이싱 자유장구간까지 인발Drawing to the outcasing free long range

Next, as shown in FIG. 3, the outcasing 7 is drawn to only the tip of the free field S1 so that the outcasing 7 is removed from the fixation section S2.

Therefore, the primary cement grout material 1a is filled in the anchorage section S2 in the absence of the out casing 7.

As such, in the present invention, the primary cement grout material 1a remains in the anchorage section S2 from which the out casing 7 is removed, thereby increasing the performance of the enlarged excavation in the enlarged excavation process and shortening the stirring time. It becomes possible.

2차 시멘트 그라우트재의 분사 및 확대 굴착 교반Spraying and Expanding Excavation of Secondary Cement Grout Material

Next, as shown in FIG. 4, after the expansion excavation stirring device 10 connected to the inner rod 5 is inserted into the outer casing 7, the secondary cement grout material is sprayed by the expansion excavation stirring device 10. Expand the excavation section (S2) excavation. When the enlarged excavation is allowed to spread out the stirring blades of the enlarged excavation device outside the tip of the outcasing (7) and then expand the excavation section (S2) while spraying the secondary cement grout material. The stirring blades rotate and reciprocate. The detailed configuration of the expansion rig stirring device 10 will be described later.

As such, while the enlarged excavation stirring device 10 is enlarged and excavated in the anchorage section S2, the secondary cement grout material is mixed with the primary cement grout material and at the same time, a small amount of soil is stirred together. Here, in the expansion excavation process, since the out casing 7 is drilled to the anchorage section and drawn out, the amount of work included in the excavation area is relatively small, so that the excavation load is reduced, and the expansion excavation work speed is improved. And enlarged excavation becomes easy. In addition, compared to the first and second cement grout material, only a small amount of small amount of the mixture is mixed, so that the density of the cement grout material is increased, and thus, high-quality expanded cement bulbs can be expected.

Here, the secondary cement grout material is preferably made in the same manner as the water-cement ratio (100% to 180%) of the primary cement grout material so that physical mixing is performed well.

On the other hand, in this process, the back pressure is formed due to the injection pressure of the secondary cement grout material sprayed from the expansion excavation stirring device 10, due to this back pressure generated in the anchorage section (S2) inside the outcasing (7) Slime is filled. This slime is a mucus mixed with a small amount of earth and sand mixed with primary and secondary cement grouts.

확대굴착 교반장치의 제거 및 시멘트 그라우트재 보충Removal of augmentation rig and replenishment of cement grout

Next, as shown in FIG. 5, the enlarged excavation stirring device 10 is removed from the out casing 7 and removed. Therefore, the primary cement grout material and the secondary cement grout material are mixed in the anchorage section S2 to form an enlarged high quality cement bulb 200.

On the other hand, by spraying the secondary cement grout material during the extraction of the expansion excavation stirring device 10 by refilling the slime inside the out casing (7) that is removed due to the extraction of the expansion excavation stirring device 10, the free field section (S) It is possible to prevent the voids from collapsing.

앵커 조립체의 삽입Insert Anchor Assembly

Next, the anchor assembly 300 having the pack 304 (or corrugated pipe) installed at the distal end of the pack 304 is inserted into the out casing 7 so that the pack 304 is positioned at the enlarged and stirred fixing section S2. Let it be. Here, the pack 304 may be made of geotextiles. When the anchor assembly 300 is installed, the pack or corrugated pipe is connected with a hose (not shown) for injecting a third cement grout material which is additionally injected. Unexplained symbol 310 is a strand.

아웃케이싱 제거Out casing removal

Then, the out casing 7 is drawn out of the ground 1 and removed to the outside as shown in FIG. The free field section with out casing 7 removed is filled with slime, so there is no concern for ground collapse.

앵커 조립체에 3차 시멘트 그라우트재 주입 충전Filling anchor assembly with tertiary cement grout

Next, a third cement grout material having a water-cement ratio of 50% or less is injected and filled into the pack 304 of the anchor assembly 300 through the hose as shown in FIG. 8A. At this time, the third cement grout material is injected through an injection hose (not shown) provided in the anchor assembly 300.

Therefore, the pack 304 of the anchor assembly 300 expands with the tertiary cement grout material filled therein, and when the tertiary cement grout material is cured, an internal anchor bulb 306 is formed as shown in FIG. 8B to enlarge the cement bulb 200. ) Has resistance to pull out.

Thereafter, the anchor assembly 300 is tensioned through a conventional method, and the anchor assembly 300 has a high pull resistance by the internal anchor bulb 306 inside the enlarged cement bulb 200.

In the present invention made as described above, since the excavation is made while additionally injecting the secondary cement grout material in the primary cement grout material portion filled in the anchorage section (S2), the stirring effect is enhanced, and the amount of small amount of cement is relatively small. It is to form a high-quality enlarged cement bulb 200 is mixed with a large amount of grout material. Therefore, the strength of the enlarged cement bulb 200 is increased, thereby reducing the risk of fracture due to the drawing of the anchor assembly 300. In addition, the enlarged cement bulb 200 forms a high-quality cement layer having a high cement density, thereby increasing adhesion to the internal anchor bulb 306, thereby improving frictional force, thereby increasing drawing resistance.

In addition, when the tertiary cement grout material filled and expanded inside the pack 304 or corrugated pipe is cured, an internal anchor bulb 306 is formed, and the internal anchor bulb 306 is integrally formed with the enlarged cement bulb 200. The pullout resistance is exhibited at.

In addition, since the enlarged excavation and agitation is performed in the primary cement grout material portion filled in the anchorage section (S2) than when the excavation stirring of the base plate of the fixing unit, the construction time can be very shortened.

On the other hand, the enlarged excavation stirring apparatus 10 applied at the time of the enlarged excavation stirring process of this method is demonstrated with reference to FIGS.

9 to 13, the enlarged excavation stirring device 10 is connected to the tip of the inner rod 5 to perform the enlarged excavation and grouting of the anchor anchor. Inner rod (5) is connected to a drive driver (not shown) is a rotation and insertion is made into the ground, there is a structure in which a hollow that is the injection passage of grout liquid formed therein.

The expansion excavation stirring device 10 includes an inner rod adapter 12, a grout injection shaft 14, an excavation head 15, a fixed side hinge block 16, a movable side hinge block 18, and a stirring blade 20. And a stirring blade operating lever 22 and a stirring blade expansion spring 24.

The inner rod adapter 12 has a penetrated hollow that is a passage of the grout material on the central axis, and a conical portion 122 extending from the screw portion 121 and the screw portion 121 with a conical angle to the outer circumferential surface thereof. At this time, the maximum outer diameter of the cone portion 122 is formed smaller than the inner diameter of the outcasing (7). Therefore, the inner rod adapter 12 is screwed with the front end of the inner rod 5 through one end of the screw portion 121. The cone portion 122 is the center of the enlarged excavation stirring device 10 when the enlarged excavation stirring device 10 is pulled out of the front end of the outcasing 7 for the enlarged excavation and then retracted into the inside of the outcasing 7. It also serves to guide the axis to easily align with the central axis of the outcasing 7.

The grout injection shaft 14 is made hollow so that the passage of the grout material is formed on the central axis. The grout injection shaft 14 is chamfered in all directions (left, right, up and down) to a circular cross section in this embodiment and has a rectangular cross section shape. Therefore, the grout injection shaft 14 prevents rotation during movement of the movable side hinge block 18 and guides linear movement. However, the cross-sectional shape of the grout injection shaft 14 is not limited to this rectangular cross section, and may be chamfered in three directions or chamfered in five or more directions depending on the number of stirring blades 20 to be installed. In addition, if the movement of the movable side hinge block 18 is to be guided through another guide means (for example, a key), the grout injection shaft 14 may have a circular cross section. The grout injection shaft 14 connects the inner rod adapter 12 and the excavation head 15. Both ends of the grout injection shaft 14 are connected to the inner rod adapter 12 and the excavation head 15 through screwing, respectively.

The grout injection shaft 14 has a plurality of grouting injection holes 141 located in a section between the fixed side hinge block 16 and the movable side hinge block 18. The plurality of grouting injection holes 141 may have a circular arrangement at regular intervals.

The drilling head 15 is coupled to the end of the grout injection shaft 14. Excavation head 15 may be a variety of forms, but as illustrated, one end of the head connection portion 151 screwed to the grout injection shaft 14, the excavation head portion formed in the other end of the head connection portion 151 in a conical shape ( 152, the grouting injection passage 153 formed extending from the head connecting portion 151 by a predetermined depth of the excavating head portion 152, the excavating bits 154 are arranged in a plurality of conical surfaces of the excavating head portion 152, It is manufactured by constructing a plurality of head grooves 155 which are formed concave at the maximum outer diameter portion of the excavating head portion 152 at regular intervals to form a passage for allowing the grout liquid to be smoothly flows to the stirring blade 20 side. have.

The drilling head 15 may further include a plurality of grouting injection holes 156 communicating with the grouting injection passage 153 and formed in the drilling head 152.

Here, the grouting injection hole 156 is formed at the center and the conical surface of the front end side of the excavation head 152. In this case, the grouting injection hole 156 formed on the conical surface of the excavation head 152 is preferably formed at an angle of 15 ° to 60 ° with respect to the central axis of the excavation head 15 in consideration of an increase in the spraying effect of the grout material.

The fixed side hinge block 16 is inserted into the grout injection shaft 14 and coupled to the other end of the inner rod adapter 12 by bolt coupling. The fixed side hinge block 16 has hinge pins 17a coupled in all directions to rotatably support the stirring blade 20.

The movable side hinge block 18 is slidably inserted into the grout injection shaft 14. The movable side hinge block 18 has the same inner diameter as the outer diameter end face of the grout injection shaft 14, so that rotation is suppressed and only linear movement is possible. The movable side hinge block 18 is coupled with hinge pins 17b in all directions.

One end of the stirring blade 20 is rotatably coupled to the movable side hinge block 18 via a hinge pin 17a. The stirring blade 20 is not limited to the illustrated length and may be increased or decreased depending on the radius of rotation required for the enlarged excavation. In the present embodiment, four stirring blades 20 are arranged on the circumference with a 90 degree interval therebetween, but two to six depending on the hinge points of the fixed side hinge block 16 and the movable side hinge block 18. Up and down is possible.

The stirring blade operating lever 22 has one end connected to the movable side hinge block 18 via a hinge pin 17b and the other end connected to the stirring wing 20 via a hinge pin 17c. The stirring blade operating lever 22 extends the stirring blade 20 according to the moving direction of the movable side hinge block 18 and expands as shown in FIG. 3 or folds as shown in FIG. 5. In addition, the stirring blade operation lever 22 is the stirring blade 20 when the expansion excavation stirring device 10 is pulled out of the front end of the out casing (7) for the enlarged excavation and then pulled back into the inside of the out casing (7) While moving, the movable side hinge block 18 is moved to compress the stirring blade expansion spring 24.

The stirring blade expansion spring 24 provides a force for compressing repulsion to allow the stirring blade 20 to be unfolded. The stirring blade extension spring 24 is inserted into the outer diameter portion of the grout injection shaft 14 and is compressed and disposed between the movable side hinge block 18 and the excavation head 15. Therefore, the stirring blade expansion spring 24 pushes the movable side hinge block 18 by the compression repulsive force to open the stirring blade 20 through the stirring blade operating lever 22. Therefore, as shown in FIG. 5, when the enlarged excavation stirring device 10 is located inside the out casing 7, the stirring blade 20 is folded to further compress the stirring wing expansion spring 24, and the enlarged excavating stirring device ( When 10) escapes from the tip of the outcasing 7, the stirring blade 20 is opened by the compression repulsion force accumulated in the stirring blade expansion spring 24.

On the other hand, the grout injection shaft 14 in the enlarged excavation stirring device 10 in the initial stage so that the stirring blade 20 can be well opened at the moment of exiting the out casing 7 while the stirring blade 20 is folded. The leaf spring 13 which provides the expansion force is further installed. The leaf spring 13 may be positioned between the fixed side hinge block 16 and the movable side hinge block 18 to be bolted or welded to the grout injection shaft 14. The leaf spring 13 is curved at both ends or one end except for the center-side fixing portion to exert elastic repulsive force. In the present embodiment, four leaf springs 13 are provided at the chamfered portions of the grout injection shaft 14 to correspond to the stirring blades 20 one-to-one. Therefore, when the stirring blade 20 is folded in the outcasing 7 as shown in FIG. 5, the leaf spring 13 is pressed by the stirring blade 20 so that both ends have elastic repulsive force. Therefore, the initial expansion operation of the stirring blades 20 occurs by the leaf spring 13 as soon as the stirring blades 20 are folded out of the casing 7 as shown in FIG. 3.

In addition, the expansion and excavation stirring device 10 may be further provided with a stirring blade stopper 142 to limit the rotation angle within a certain time when the stirring blade 20 is rotated to expand. The stirring blade stopper 142 is positioned between the fixed side hinge block 16 and the movable side hinge block 18 and is fixed to the grout injection shaft 14 via a stopper bolt 143. In this embodiment, the stirring blade stopper 142 is configured as a ring, but is not limited to this form. At this time, the stopper bolt 143 is positioned in the cutting groove 14a of the grout injection shaft 14 to be fastened to fix the position of the stopper 142 for the stirring blade.

In addition, the enlarged excavation stirring device 10 is preferably formed in the inner rod adapter 12 and the fixed side hinge block 16 is formed with a plurality of slime discharge passage 19 for smoothing the slime when the cement bulb is formed on the outer peripheral surface. Do. In the slime discharge passage 19, the enlarged excavation stirring device 10 exits the out casing 7 to form a primary enlarged cement bulb by enlarged excavation and stirring, and then the enlarged excavating stirring device 10 is out casinged. When it is drawn back into the inside of 7), it forms a secondary cement bulb and smoothes slime discharge.

The enlarged excavation stirring device 10 configured as described above is charged into the inside of the outcasing 7 in a state in which the stirring blade 20 is forcibly folded as shown in FIG. 13 to form an enlarged cement bulb, and then out as shown in FIG. 4. When exiting the tip of the casing (7), the stirring blade 20 is automatically unfolded by the compression repulsive force of the stirring blade expansion spring 24, it is possible to prepare for expansion excavation.

Therefore, in the enlarged excavation stirring process, the stirring blade 20 is rotated in the open state and the cement grout material is discharged through the grouting injection hole 156 to simultaneously excavate and stir to form a high quality enlarged cement bulb 200 after curing. do.

As such, the enlarged excavation agitator 10 may automatically expand the stirring blade 20 mechanically by using the stirring blade extension spring 24 without using a separate power, thereby eliminating the need for an electric power device. The configuration is simpler, so it is easier to manufacture and there is less fear of failure.

So far, the present invention has been described in detail with reference to the presented embodiments, but those skilled in the art may make various modifications and modifications without departing from the technical spirit of the present invention with reference to the presented embodiments. will be. The invention is not limited by the invention as such variations and modifications but only by the claims appended hereto.

The anchorage expansion type ground anchor using the expansion excavation stirring device of the present invention is agitation effect is enhanced because expansion excavation is made while injecting the secondary cement grout material from the primary cement grout material portion filled in the anchorage section, Alternatively, when the expanded tertiary cement grout material is filled in the inside of the ERP corrugated pipe, the high quality cemented bulb prevents the anchor body from escaping and improves the tension tightening performance. Expansion excavation and stirring is performed in the primary cement grout portion filled in the section has the advantage that can significantly shorten the construction time. In addition, the enlarged excavation stirring device applied in the present method is capable of automatically expanding the stirring blade mechanically by the stirring blade expansion spring without using a separate power, thereby eliminating the need for an electric power device and simplifying the configuration. It is a very useful invention that is easy to manufacture and less trouble of failure.

Claims

(a) an outcasing anchorage drilling step of carrying out a drilling operation by introducing the outcasing 7 into the ground 1 to the tip of the anchorage section S2;

(b) primary cement grout material injection step of injecting primary cement grout material into the anchorage section S2 into the out casing 7;

(c) an out casing drawing step of drawing the out casing 7 only to the tip of the free field section S1 to remove the out casing 7 from the anchorage section S2;

(d) After inserting the expansion excavation stirring device 10 connected to the inner rod 5 into the inside of the out casing 7, the expansion excavation stirring device 10 is sprayed with a secondary cement grout material, S2) enlarged excavation stirring device 10 by rotating and reciprocating to expand and excavate to form an enlarged cement bulb 200, and at the same time to enlarge the cement filling the slime into the out casing 7 with the back pressure generated during stirring Bulb formation step;

(e) Expanding excavation stirring device 10 and cement grout, which draw out and remove the enlarged excavation stirring device 10 from the outcasing 7 and at the same time replenish the cement grout material by a small amount of slime released from the outcasing 7. Replenishment step;

(f) inserting and positioning the anchor assembly 300 having the geotextile (pack) or corrugated pipe installed at the distal end thereof in the enlarged and stirred anchorage section (S2);

(g) an outcasing removing step of extracting the outcasing 7 from the ground 1 and removing it outward; And

(h) injecting a tertiary cement grout material into the pack 304 or corrugated pipe of the anchor assembly 300 to form an anchor bulb 306 to form an anchor bulb; Expansion anchor type ground anchor construction method using stirring device.
The method of claim 1,

In the step (b) and step (d), the primary cement grout material and the secondary cement grout material, respectively, is a water-cement ratio of 100% to 180%, and the expansion site expansion type using the expansion excavation stirring device Ground anchor construction method.
The method of claim 1,

In the step (h), the tertiary cement grout material is anchorage expansion type ground anchor construction method using an expansion excavation stirring device, characterized in that the water-cement ratio is 50% or less.
The method of claim 1,

The enlarged excavation stirring device 10,

An inner rod adapter 12 coupled to the inner rod 5 through a screw connection;

A grout injection shaft coupled to the other end of the inner rod adapter 12 and having a plurality of grouting injection holes 141 located in a section between the fixed side hinge block 16 and the movable side hinge block 18. 14;

An excavation head 15 coupled to the distal end of the grout injection shaft 14;

A fixed side hinge block (16) inserted into the grout injection shaft (14) and fixed to the other end of the inner rod adapter (12);

A movable side hinge block (18) movably inserted into the grout injection shaft (14);

A stirring blade 20 whose one end is rotatably hinged to the movable side hinge block 18;

A stirring blade operating lever 22 having one end hinged to the movable side hinge block 18 and the other end hinged to the stirring blade 20;

The stirring blade is inserted between the outer diameter portion of the grout injection shaft 14 and is disposed between the movable side hinge block 18 and the excavation head 15 to provide an expansion force to open the stirring blade 20. An anchorage expansion-type ground anchor construction method using an expansion excavation stirring device, characterized in that it comprises an expansion spring (24).
The method of claim 4, wherein

The stir blade 20 is a fixed length expansion-type ground anchor construction method using an expansion excavation stirring device, characterized in that arranged at intervals of 90 degrees around the grout injection shaft (14).
The method of claim 4, wherein

The grout injection shaft 14 is positioned between the fixed side hinge block 16 and the movable side hinge block 18 to provide an initial expansion force to the folded stirring blade 20 exiting the out casing 7. An anchorage expansion-type ground anchor construction method using the expansion excavation stirring device, characterized in that the plate spring (13) fixed to the) is further provided.
The method of claim 4, wherein

When the stirring blade 20 is rotated and expanded, it is positioned between the fixed side hinge block 16 and the movable side hinge block 18 to limit the rotation angle within a predetermined distance to the grout injection shaft 14. An anchorage expansion-type ground anchor construction method using an enlarged excavation stirring device, characterized in that the stopper 142 for the stirring blade is fixed.
The method of claim 4, wherein

The excavation head 15,

A head connection portion 151, one end of which is screwed into the grout injection shaft 14;

An excavation head portion 152 formed conically in the other end of the head connection portion 151;

A grouting injection passage 153 extending from the head connecting portion 151 by a predetermined depth of the excavating head portion 152;

An excavation bit 154 attached to the conical surface of the excavation head 152 at regular intervals;

Produced by forming a plurality of head grooves 155 to form a passage for forming a conduit so that the grout liquid is injected into the maximum outer diameter portion of the excavating head portion 152 at regular intervals to flow smoothly toward the stirring blade 20 side An anchorage expansion-type ground anchor construction method using an enlarged excavation agitation device, characterized in that.
The method of claim 4, wherein

The inner rod adapter 12 and the fixed side hinge block 16 has an enlarged excavation stirring device, characterized in that a plurality of slime discharge passages 19 are formed on the outer circumferential surface to smooth the slime of the clay when the cement bulb is formed. Expansion anchor type ground anchor construction method using
The method of claim 8,

A plurality of grouting injection holes 156 are further formed in the excavation head portion 152, and the anchorage expansion-type ground anchor construction method using the expansion excavation stirring device.