JP2019044543A - Method for injecting solidification agent into excavation hole, and excavation rod - Google Patents

Abstract

To make it possible to form two types of solidification agent layers with good quality efficiently.SOLUTION: An excavation rod 40 is made by joining an excavation head 30 to the lower end of a rod body 1 in which unit rods 3A, 3B, 3C are connected (Figure a). The unit rod 3B is provided with a closing cylinder 7 that locks on a locking tool 13 to close an upper discharge port 6 of an outer wall and that can slide inside the unit rod 3B (Figures b, c). If the excavation of an excavation hole using the excavation rod 30 is finished, a solidification agent is discharged from a lower discharge port 34 through a liquid passage 2 from above ground, and the excavation rod 40 is raised while forming a first solidification agent layer. Next, a switching top 20 is dropped in the liquid passage 2 from above the rod body 1 (Figure c), a tapered side surface 22 of the switching top 20 releases the locking of the locking tool 13. The switching top 20 and the closing cylinder 7 fall to open the upper discharge port 6. At the same time, since the switching top 20 closes the hollow part of the closing cylinder 7 to block the liquid passage 2 below, a second solidification layer can be formed by discharging a solidification agent from the upper discharge port 6 through the liquid passage 2 from above ground.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for injecting a solidifying agent such as a circumferential fixing liquid into a shaft mainly in a drilling hole (pile hole), and to a drilling rod used in the injection method.

  When a prefabricated pile is embedded in a pre-excavated pile hole to construct a foundation pile, cement milk or the like is placed between the sidewall of the pile hole and the outer periphery of the prefabricated pile in order to enhance the integrity of the ground and the prefabricated pile. It was filled with a solidifying agent. Since the pile hole residue (excavated mud, lumps of residual soil, water) remains in the pile hole when digging the pile hole, it has been required to uniformly stir the solidifying agent. Moreover, discharge of the solidifying agent is performed from the discharge port provided near the lower end of the drilling rod (with the drilling head attached) by supplying the solidifying agent from the plant on the ground to the hollow portion of the drilling rod.

  In particular, since the quality of the injection of the solidifying agent is directly linked to the tip supporting force at the root portion of the pile hole, the solidifying agent is injected from the lower end of the drilling rod (near the bottom of the pile hole) to replace it with the pile hole residue It has been devised to move the drilling rod up and down to stir the solidifying agent (Patent Document 1). Furthermore, in recent years, in order to further increase the strength at the shaft portion, equalization of the solidifying agent at the shaft portion of the pile hole is also required. In this case, when discharging the solidifying agent while moving the drilling rod vertically There was also.

  In general, the discharge port for the solidifying agent is disposed at the lower end of the drilling rod (lower end of the drilling head) (Patent Documents 1 to 3), and the discharging of the solidifying agent to the shaft of the pile hole is usually the drilling rod In order to discharge from the lower end of the drilling rod while pulling up, it is necessary to move the drilling rod up and down largely in order to stir the solidifying agent protruding from the lower end of the drilling rod.

JP 2012-136875 A JP 2008-157014 A JP, 2006-233749, A

  As described above, when pulling up the drilling rod while moving the drilling rod up and down greatly, there is a problem that it takes time to pull up the drilling rod. Therefore, in the present invention, in order to omit or reduce the vertical movement of the drilling rod, a discharge opening near the lower end of the drilling rod for the rooting portion and a discharge opening for the shaft above it and a discharge opening at two locations Decided to

  In this case, a switch valve is provided in the drilling rod to select a discharge port (Patent Document 2), and a scheme in which two pipes for upper and lower are provided in the drilling rod (Patent Document 3) Has been proposed. In the former case, it was not practical to operate the switching valve from the ground, and in the case of equipping the latter two pipes, the connecting structure of the drilling rod was complicated, which was also not realistic. Therefore, according to the present invention, the operation piece is dropped in the solidifying agent supply pipe, and the switching passage switches the flow path of the solidifying agent from the lower discharge port to the upper discharge port.

  In the present invention, in the method of injecting the solidifying agent, the upper discharge port is formed above the upper discharge port near the lower end of the digging rod and above the drilling head, and both discharge ports are switched by the switching unit. In the case of the drilling rod, the above problem is solved as a structure in which the lower discharge port is switched to the upper discharge port by the switching piece dropped from above in the solidifying agent supply pipe.

That is, the invention of this method is characterized in that the drilling hole is drilled with a drilling head equipped at the lower end of the drilling rod, and a solidifying agent is filled in the drilling hole as follows to form a solidifying agent layer in the drilling hole It is a method of injecting the solidifying agent into the drilling hole.
(1) The said drilling rod provided the lower discharge port in the said drilling head, and provided the upper discharge port above the said drilling head.
(2) When the drilling of the drilling hole is completed, a solidifying agent is injected from the lower discharge port to the lower end of the drilling hole to replace the drilling hole residue with the solidifying agent, or the solidifying agent and the inside of the drilling hole Stir and mix the residue.
(3) While pulling up the drilling rod, a solidifying agent is injected from the lower discharge port to a predetermined height of the drilling hole set in advance to form a first solidifying agent layer.
(4) The discharge port is switched from the lower discharge port to the upper discharge port at the predetermined height.
(5) A solidifying agent is injected into the excavated hole from the upper discharge port, and while pulling up the digging rod, the discharged solidifying agent is stirred with the residue in the pile hole to form a second solidifying agent layer.
(6) While performing the operation of (5), the drilling rod is pulled up to the ground to complete the injection of the solidifying agent into the drilling hole.

Also, the invention of the other method is to dig the wellbore with the digging head equipped at the lower end of the digging rod, fill the solidifying agent into the wellbore as follows, and place the high strength solidifying agent layer in the wellbore and A method of injecting a solidifying agent into a wellbore characterized by forming a solidifying agent layer.
(1) The said drilling rod provided the lower discharge port in the said drilling head, and provided the upper discharge port above the said drilling head.
(2) When the drilling of the drilling hole is completed, a solidifying agent is injected from the lower discharge port to the lower end of the drilling hole to replace the drilling hole residue and the solidifying agent, or the solidifying agent and the inside of the drilling hole Stir and mix the residue.
(3) While pulling up the drilling rod, a solidifying agent is injected from the lower discharge port to a predetermined height of the drilling hole set in advance to form a high strength solidifying agent layer.
(4) The discharge port is switched from the lower discharge port to the upper discharge port at the predetermined height.
(5) A solidifying agent is injected into the excavated hole from the upper discharge port, and the solidified solidifying agent layer is formed by stirring the discharged solidifying agent with the residue in the pile hole while pulling up the digging rod.
(6) While performing the operation of (5), the drilling rod is pulled up to the ground to complete the injection of the solidifying agent into the drilling hole.

Moreover, in the invention of each said method, it is the injection | pouring method of the solidification agent in the pile hole comprised as follows.
(1) A kneading drum is disposed below the upper discharge port by a drilling rod, and the solidifying agent is stirred immediately after injecting the solidifying agent from the upper discharge port into the drilling hole while pulling up the drilling rod. Level the hole wall.

Further, in the invention of each of the above-described methods, it is a method of injecting a solidifying agent into a wellbore configured as follows.
(1) Once the lower discharge port reaches the preset depth position, the raising of the digging rod is once stopped.
(2) Close the lower discharge port and open the upper discharge port.
(3) Before or after (2), the drilling rod is moved down or raised to position the upper discharge port near the set depth position, and the solidifying agent is discharged from the upper discharge port. Raise or lower the drilling rod.

Moreover, the invention of this rod equips the lower end with a digging head, It is a digging rod characterized by having comprised as follows.
(1) A liquid passage for conveying the solidifying agent supplied from the solidifying agent supply device on the ground to the discharge port was formed in the hollow portion of the digging rod.
(2) The lower end of the front fluid passage was connected to the lower discharge port formed in the drilling head.
(3) The upper discharge port is formed at the height position above the drilling head by the digging rod, and the upper discharge port is connected through the branch portion formed in the liquid path.
(4) The upper discharge port was closed by the upper discharge port closure.
(5) The liquid passage can supply the switching tool from above to the branch portion.
(6) When the switching tool reaches the branch portion, the closing of the upper discharge port by the closing tool is released to open the upper discharge port, and the lower discharge port can be closed.

Moreover, in the invention of the said rod, it is a digging rod comprised as follows.
(1) The drilling rod is provided with a kneading drum above the drilling head for kneading the wall of the drilling hole, and an upper discharge port is formed immediately above the kneading drum.

Moreover, the invention of the other rod equips the lower end with a digging head, It is a digging rod characterized by having comprised as follows.
(1) A liquid passage for conveying the solidifying agent supplied from the solidifying agent supply device on the ground to the discharge port was formed in the hollow portion of the digging rod.
(2) The lower end of the front fluid passage was connected to the lower discharge port formed in the drilling head.
(3) The drilling rod is provided with a kneading drum for kneading the drilling hole wall at a height position above the drilling head, and an upper discharge port is formed immediately above the kneading drum.
(4) The upper discharge port is connected through the branch portion formed in the liquid passage.
(5) The upper discharge port is closed by the closing tool of the upper discharge port, and further, the closing by the closing tool is released to open the upper discharge port and the switching tool capable of closing the lower discharge port is provided.

The “high strength solidifying agent layer” and the “ordinary solidifying agent layer” in the above-mentioned state have a solidification strength in a state where the solidifying agent (cement milk etc.) is solidified
"Normal solidifying agent layer"<"High strength solidifying agent layer"
It should just be. Generally, the ratio of the amount of solidifying agent such as cement milk having the same solidifying strength (water-cement ratio etc.) as compared to the solidifying agent's injecting space (volume of the planned drilling hole's part) in the pile hole In the case of the "high strength solidifying agent layer" more than the agent layer ", it is formed. The “high-strength solidifying agent layer” and the “ordinary solidifying agent layer” are formed by other methods such as forming using a solidifying agent different in the solidification strength (such as water-cement ratio) of cement milk to be input. You can also

  In this invention, since the upper discharge port is provided immediately above the drilling head by the drilling rod, after drilling the drilling hole by the drilling head, the solidifying agent introduced from the upper discharge port into the drilling hole is immediately stirred by the drilling head. Can form a good solidifying agent layer. Furthermore, if a kneading drum is provided immediately below the upper discharge port, the solidifying agent introduced into the drilling hole from the upper discharge port can be immediately stirred and kneaded by the mixing drum, so that a higher quality solidifying agent layer can be formed. .

(A) is a front view of the digging rod of the present invention, (b) is an enlarged longitudinal sectional view of A part of (a), (c) is an enlarged longitudinal sectional view of B part of (b). (A)-(h) represent the schematic longitudinal cross-sectional view explaining the construction method of this invention. In the first embodiment showing the operation of the discharge switching portion of the drilling rod of the present invention, (a) is a plan view and a vertical cross-sectional view of the lower discharge state, (b) (c) is a vertical cross-sectional view at the time of switching (D) represents a longitudinal sectional view of the upper discharge state. (A) (b) (c) represents a partially enlarged view of (a) (b) (c) in Figure 3. (A) is a cross-sectional view and an XYZ cross-sectional view of the lower discharge state in the second embodiment showing the operation of the discharge switching portion of the drilling rod of the present invention, (b) and (c) are XYZ cross-sectional views at the time of switching Here, (d) represents an XYZ cross-sectional view of the upper discharge state.

An embodiment of the present invention will be described based on the drawings.

1. Configuration of drilling rod 40

(1) The digging head 30 is connected to the lower end of the rod body 1 to form a digging rod 40 (FIG. 1 (a)). In addition, the rod main body 1 is formed from the cylinder (pipe body) which has a hollow part.
The rod main body 1 is configured by connecting the required number of unit rods 3A, the unit rods 3B, and the unit rods 3C vertically. A unit rod 3B provided with a unit rod 3A of a standard part, a unit rod 3B provided with an upper discharge port 6 and a branched part 25 near the upper discharge port 6, and a unit rod attached with kneading drums 5 and 5 around the unit rod 3A of a standard part. Prepare 3C. Each unit rod 3A, 3B, 3C forms a liquid passage 2 in the hollow portion.

(2) The unit rod 3B is provided with a through hole connected to the hollow portion (liquid path) in the outer wall to provide a closed cylinder (closer) 7 as the upper discharge port 6 for closing the upper discharge port 6 (through hole). The closed cylinder 7 is a cylindrical body provided with an outer diameter smaller than the inner diameter (2 × R0) of the rod main body 1 and is an upper and lower annular locking rib which can be in close contact with the inner wall 1a of the rod main body 1 Eight and nine are provided. The upper annular rib 8 and the lower annular rib 9 are respectively located above and below the upper discharge port 6 at the time of closing, and can cooperate with the outer wall surface of the closing cylinder 7 to shut off the liquid passage 2 and the discharge port 6 And, in the normal use condition, it is formed in a size that can slide in the inner wall 1a of the rod body 1 (Fig. 1 (b) (c)). Therefore, when the maximum outer diameter of the upper annular rib 8 and the lower annular rib 9 is “2 × R2”, the maximum outer diameter of the closed cylinder 7 (2 × R2) <the inner diameter of the rod main body 1 (2 × R0)
It is formed of Moreover, let the internal diameter of the closed cylinder 7 be "2xR1."
A locking member 13 is provided on the inner wall of the unit rod 3B for locking the upper annular rib 8 of the closing cylinder 7 at the time of closing the upper discharge port 6 and maintaining the closing cylinder 7 so as not to fall inside the unit rod 3B. . The fastener 13 is accommodated in a recess 11 formed in the inner wall of the unit rod 3B, is urged inward by a spring 17, and provides at least two at diametrically symmetrical positions. The locking member 13 has an upper operation claw 14 provided with a lower locking claw (small protrusion amount) for locking the upper annular rib 8 of the closing cylinder 7 at the lower side and a claw having a large protrusion amount toward the center side, And are formed. The upper operation claw 14 forms an inclined surface with a downward slope toward the center side (inward) on the upper surface. Also, two or more fasteners 13, 13 may be provided at least diametrically (FIG. 1 (c)) centered on the axis of the unit rod 3A, or three or more may be provided rotationally symmetrical (not shown) .

(3) Further, the stopper 18 is provided to project below the upper discharge port 6 on the inner wall of the unit rod 3B. The stopper 18 is provided at a position where the upper discharge port 6 is opened when the closed cylinder 7 from which the locking tool 13 is released is lowered (when the lower end of the closed cylinder 7 contacts the stopper 18, closing). The upper end of the cylinder 7 is provided so as not to be associated with the upper discharge port 6), and is formed in such a size that there is no hindrance to the flow of the solidifying agent etc. in the normal liquid passage 2 (FIG. 3 (a).

(4) The switching piece (switching tool) 20 has a flat circular large-diameter portion 21 (diameter 2 × R3) formed at the top, and the tapered side surface 22 has a small diameter toward the bottom, and a small-diameter portion 23 is formed at the bottom And be configured. Assuming that the inner diameter (2 × R0) of the unit rod 3A and the inner diameter (2 × R1) of the closed cylinder 20, the maximum outer diameter (2 × R3) of the large diameter portion 21 of the switching piece 20 Radius (2 × R3)
<Internal diameter of unit rod 3A (2 × R0)
Inner diameter of closed cylinder 7 (2 × R1)
<Maximum radius of large diameter portion 21 (2 × R3)
It has become. That is, the switching piece 20 can be moved with a gap in the unit rod 3A, and the large diameter portion 21 of the closing piece 20 can close the upper edge of the closing cylinder 7.
Also, with the lower locking claw 16 biased inward by the spring 17 and positioned inward to lock the lower edge of the upper annular rib 8 of the closed cylinder 7 (FIG. 1 (c)), the unit rod Assuming that the distance from the axis 10 of 3A to the inner edge 15 (the tip of the inner side) of the upper operation claw 14 is R4, the diameter of the circle passing through the inner edge 15 of each upper locking claw is "2 × R4". At this time, assuming that the radius R3 of the large diameter portion 21 of the switching piece 20,
Diameter of circle passing through inner edge 15 of each upper locking claw (2 × R4)
<Diameter of large diameter portion 21 of switching piece 20 (2 × R3)
It has become.
Further, the length (height) (L3) of the switching piece 20 is
Inner diameter of unit rod 3A (2R0) <length (height) L3 of switching piece 20
The large diameter portion 21 is always positioned on the upper side when inserted into the unit rod 3A (FIG. 1 (c)).
Further, a mechanism in which the upper discharge port 6 and the closing cylinder 7 are provided and the switching piece 20 is combined is referred to as a branch portion 25. Therefore, in this embodiment, the positions of the branch 25 and the upper discharge port 6 are the same, but if the closing structure of the upper discharge port 6 is different, the positions of the branch 25 and the upper discharge port 6 are different (Not shown).

(5) The digging head 30 is configured by attaching the swingable digging arms 36, 36 to the head body 31 and forming a connecting portion 32 connecting the unit rods 3C (3A, 3B) to the upper end portion of the head body 31. It is Also, movable digging blades 37 are provided at the lower end portion of the digging arm 36, and fixed digging blades 33 are provided at the lower end face of the head main body 31 (FIG. 1A).
Further, the connecting portion 32 is formed hollow, and a fluid passage 32a communicating with the fluid passage 2 of the rod main body 1 (the unit rods 3A, 3B, 3C) is formed. Further, the fluid passage 32 a of the connecting portion 32 communicates with the fluid passage 35 in the head main body 31 and reaches the lower discharge port 34 formed on the lower surface of the head main body 31.
In addition, an open / close valve can be disposed in the lower discharge port 34, and if this valve is opened, it is possible to discharge the solidifying agent and the like passing through the fluid passages 2, 32a and 35 to the outside of the drilling head 30. .

(6) Unit rod 3C provided with kneading drums 5 and 5 is connected to connecting portion 32 of drilling head 30, unit rod 3B provided with upper discharge port 6 is connected thereon, and the necessary number is provided thereon The standard unit rods 3A, 3A are connected to constitute the drilling rod 40 of the present invention (FIG. 1 (a)).

2. Pile hole drilling method

(1) A drilling rod 40 in which a unit rod 3A, a unit rod 3B, a unit rod 3C, and a drilling head 30 (in a state in which the drilling arm 36 is closed) is sequentially connected is attached to the drilling machine. With the upper discharge port 6 closed by the closed cylinder 7, the fluid passages 2, 32 a and 35 of the drilling rod 40 are open at the lower discharge port 34 of the drilling head 40.
The excavation rod 40 (excavator) is rotated to excavate the pile hole shaft portion 42 with a diameter D10 from the ground 41 (FIG. 2 (a)). The drilling rod 40 is held on the ground 41, and while the next unit rod 3A is connected to the uppermost unit rod 3A, the length of the rod main body 1 is sequentially lengthened and the diameter D10 is increased to a predetermined depth. The pile hole shaft 42 is excavated (FIG. 2 (b)). At this time, if necessary, the drilling fluid (water) is discharged from the lower discharge port 34 of the drilling head 40 from the ground 41 through the fluid passages 2, 32a, 35.
Subsequently, the drilling arms 36, 36 are opened to set the diameter expansion mode, and the pile hole bottom portion 43 is excavated with a diameter D20 (> D10) so as to widen the outer wall of the pile hole shaft portion 42 (FIG. 2 (c)) .
When the excavation of the pile hole expanded portion 43 is completed (FIG. 2 (c)), the material to be flowed to the fluid path 2 is switched from drilling fluid to rooting fluid (cement milk) at the ground 41 and the drilling head 40 is piled. Positioned at the bottom 43a of the hole expanding portion 43 (FIG. 2C), the rooting solution is supplied from the ground 41, and the rooting solution is discharged from the lower discharge port 34 of the drilling head 40, and the pile hole expanding portion Replace the pile hole residual material (water, excavated residual soil, etc.) in the 43 with the rooting liquid, and place the drilling head 40 on the upper end of the pile hole expanded bottom portion 43 (lower end of the pile hole shaft portion 42). A rooting liquid layer (strong solidifying agent layer) 45 is formed in the expanded portion 43 (FIG. 2 (d)). At this time, since the upper discharge port 6 is closed by the closing cylinder 7, the rooting fluid passes through the inside of the closing cylinder 7 at the branch portion 25 and is sent downward (Fig. 1 (b), Fig. 3). (A), leading to the lower discharge port 34.
In addition. In this case, depending on the conditions of the construction site, it is possible to form a soil cement by stirring and mixing the pile hole residue and the rooting liquid.

(2) With the rooting liquid layer 45 formed (FIG. 2 (d)), the upper discharge port 6 is slightly (predetermined distance) from the upper end 43b (the lower end 42a of the pile hole shaft portion 42) of the pile hole expanded portion 43 ) Above (Fig. 2 (d)).
Then, once the drilling rod 40 is removed from the drilling machine (or removed from the unit rod 3A at the top stage attached to the piling machine), the lower portion thereof is maintained so as to maintain the current depth '(height). The unit rod 3A portion is held on the ground 41. The switching piece 20 is inserted into the hollow portion (liquid path 2) of the unit rod 3A whose upper end is open. In this state, generally, since the hollow portion (liquid path 2) of the unit rod 3A whose upper end is open is filled with the rooting fluid, the switching piece floats up or falls gently in the rooting fluid. It is a situation.
And unit rod 3A which the upper end opened again is connected with a pile driver (or unit rod 3A of the top step), the holding by the ground 41 is removed, and upper discharge port 6 is pile hole bottom part 45 (root consolidation) The digging rod 40 is once lowered so as to be located at the upper end 43 b (the lower end 42 a of the pile hole shaft 42) of the layer) (FIG. 2 (e)).
Here, in a state in which the rooting liquid layer 45 is formed (FIG. 2 (d)), the upper discharge port 6 is substantially the same as the upper end 43b (the lower end 42a of the pile hole shaft portion 42) of the pile hole expanded portion 43. Or a position slightly below the upper end 43 b (the lower end 42 a of the pile hole shaft 42) (not shown). In this case, the operation of (3) below is unnecessary or the operation of lowering and raising is reversed.

(3) In the above (2), before inserting the switching piece 20, the digging rod 40 is lowered, and the upper discharge port 6 is the upper end 43b (pile hole shaft of the pile hole expanding portion 45 (rooting layer) The digging rod 40 can also be held on the ground 41 while being positioned at the lower end 42a) of the portion 42 (FIG. 2 (e)). In this case, after the switching piece 20 is inserted into the unit rod 3A and the digging rod 40 is released from the ground 41, the digging rod 40 is raised immediately.

(4) Subsequently, the circumferential fixing liquid (cement milk) is allowed to flow to the liquid passage 2 from the ground 41. By the flow of the pile peripheral fixing liquid, the switching piece 20 located above the liquid passage 2 flows downward and descends to the upper side of the closing cylinder 7 (FIG. 3 (b), FIG. 4 (a)). Subsequently, the upper end portion and the large diameter portion 21 of the tapered side surface 22 of the switching piece 20 hit the upper operation claw 14 (inner edge 15) of the locking member 13 and resist the spring 17 into the recess 11. Push out. At the same time, the locking between the lower locking claw 16 of the locking tool 13 and the upper annular rib 8 of the closing cylinder 7 is released (FIG. 4 (b)). Therefore, the upper end portion and the large diameter portion 21 of the tapered side surface 22 of the switching piece 20 which continues to descend push the upper end of the closing cylinder 7, and the closing cylinder 7 descends together with the switching piece 20. The lower portion of the tapered side surface 22 of the switching piece 20 The small diameter portion 23 enters the closed cylinder 7, and the upper end of the tapered side surface 22 and the large diameter portion 21 close the upper surface of the closed cylinder 7 (FIG. 4 (b), FIG. 3 (c)). Further, also in the case where the lowered switching piece 20 has its tapered side surface 22 in contact with the lower locking claw 16 of the locking tool 13 which is biased again inward (in the centripetal direction of the shaft 10) by the spring 17. However, since the tapered surface 22 pushes the lower locking claw 16 outward (in the radial direction from the shaft 10), the switching piece 20 descends beyond the lower locking claw 16 (FIG. 4 (c)).
Further, the switching piece 20 and the closing cylinder 7 are lowered, and the upper discharge port 6 is opened from the upper side (FIG. 4 (c), FIG. 3 (c)). The switching piece 20 and the closing cylinder 7 are closed cylinder 7 The descent is stopped in a state where the lower end of the lower part is in contact with the stopper 18, and the upper discharge port is fully opened (FIG. 3 (d)). Therefore, since the hollow portion of the closed cylinder 7 is closed by the switching piece 20, the pile peripheral fixing liquid flowing through the liquid passage 2 from above does not flow downward (on the lower discharge port 34 side), and It is discharged from the upper discharge port 6 into the pile hole shaft portion 42 (Fig. 2 (e), Fig. 3 (d)).

(5) The upper discharge port 6 of the drilling rod 40 is located at the upper end 43 b (lower end 42 a of the pile hole shaft portion 42) of the pile hole expanded bottom portion 43 (peptized layer 45). If it is raised while the pile peripheral fixing liquid discharged is immediately stirred by the kneading drums 5, 5 of the unit rod 3C rising from immediately below, the pile holes immediately on the outer peripheral surface of the kneading drums 5, 5 It is kneaded on the wall. Moreover, the pile peripheral fixing liquid (solidifying agent) injected from the upper discharge port 6 is also stirred by the drilling head 30 (partially digged into the pile hole wall by the drilling arms 36, 36). Therefore, the pile peripheral fixing liquid can be efficiently mixed with the pile hole residue efficiently, and can be efficiently kneaded to the pile hole wall to form a rooting liquid layer 46 (normal solidifying agent layer) of good quality (FIG. f) (g)).

(6) If the drilling rod 40 is pulled up to the ground 41 with this operation, the rooting layer 45 and the pile circumferential fixing liquid layer 46 can be formed in the pile holes 42 and 43 (FIG. 2 (h)).
Thereafter, a prefabricated pile is embedded in the pile holes 42, 43 by a conventional method to construct a foundation pile (not shown).

(7) In the above embodiment, the solidifying agent is cement milk having the same solidification strength (such as water-cement ratio).
Although it is referred to as “peripheral fixing liquid <rooting liquid”, cement milk with larger solidification strength (water-cement ratio etc.) can also be used as the rooting liquid.
Moreover, although the pile hole enlarged bottom part 43 was formed by the diameter D20 in the said embodiment, it can also form with the same diameter D10 as the pile hole axial part 42 (not shown).
In addition, in the embodiment, the method may be applied to soft ground to make the solidifying agent a ground improver. In this case, the prefabricated pile is not embedded in the pile hole which has been excavated to form the solidifying agent layer.

3. Other embodiments

(1) In the above embodiment, the drilling rod 40 can be configured by further connecting the unit rods 3C attached with the kneading drums 5 and 5 above the unit rods 3B (upper discharge port 6) (shown in the drawing) Not). That is, the kneading drum 5 is positioned above and below the upper discharge port 6.
Further, in the above embodiment, the unit rod 3C attached with the unit rods 3C attached with the kneading drums 5 and 5 is omitted, and the unit rod 3B is connected directly above the excavating rod 30 to constitute the excavating rod 40. Can also be done (not shown).
Moreover, in the said embodiment, it can also be set as the structure by which the unit rod 3B or the unit rod 3C was fixed to the excavation head 30 (not shown). That is, the kneading drums 5 and 5 and the upper discharge port 6 are formed at the upper end portion of the head main body 31.

(2) Further, in the embodiment described above, the locking tool 13 is disposed in the recess 11, and the flow of the liquid passage 2 of the unit rod 3A is made downward by the closing cylinder 7 and the switching piece 20 (lower discharge port 34). Although it has been switched whether to flow to the side or to the upper discharge port 6b, another switching structure may be employed (not shown).

(3) Further, in the above embodiment, since the lower discharge port 34 is provided at the lower end of the head main body 31, when forming the rooting layer 45, the solidifying agent can be injected from near the bottom 43a of the pile hole enlarged bottom portion 43. Also, although it is effective because the drilling fluid can be poured in the vicinity of the cutting blades 33, 37, it can be provided at another position of the drilling head 40 (not shown).

(4) In the above embodiment, although the rod main body 1 (unit rods 3A, 3B, 3C) is a single cylinder, the double rod cylinder consisting of the inner cylinder 51 and the outer cylinder 53 The unit rods 3A, 3B, 3C) can also be configured (FIG. 5). In this case, different types of fluids can be introduced into the pile holes simultaneously or at different times. Therefore, in this case, the inside of the inner cylinder 51 is the liquid passage 2, and the outer wall of the inner cylinder 51 and the inner wall of the outer cylinder 53 constitute the liquid passage 2 a.
For example, in the unit rod 3A, the inner cylinder 51 and the outer cylinder 53 connect the through holes 52 of the inner cylinder 51 and the through holes 54 of the outer cylinder 53 with the connecting horizontal cylinder 55 to form the upper discharge port 56. There is (FIG. 5 (a)). In this case, a unit rod 3A (FIG. 3A) of the single cylinder is used as an inner cylinder 51, and an outer cylinder 53 having a through hole 54 formed on the outer side is covered. Therefore, the inner cylinder 51 is provided with the closing cylinder 7 for closing the through hole 52 (upper discharge port 6) and the locking tool 13 for disengaging the closing cylinder 7 in the recess 11 as in the embodiment described above. And the switching piece 20 which operates the locking tool 13 is combined, and the switching structure is comprised (refer FIG. 1 (c), FIG. 4).
Therefore, in the normal state, the closing cylinder 7 is locked to the locking tool 13 (see FIG. 4A), the upper discharge port 56 (through hole 52) is closed by the closing cylinder 7, and the solidification passing through the liquid passage 2 is achieved. The agent passes through the hollow portion of the closed cylinder 7 and is introduced into the pile holes 42, 43 from the lower discharge port 34 (FIG. 5 (a)).
Similar to the embodiment described above, when the switching piece 20 is inserted into the inner cylinder 51 (FIG. 5 (b)), the locking piece 13 of the locking tool 13 is released by the switching piece 20 (FIG. 4 (b) (C)), the closed cylinder 7 whose upper end is closed by the switching piece 20 falls downward (Fig. 5 (c), and when it comes in contact with the stopper 18, the through hole 52 is fully opened, and the connection is communicated) The solidifying agent is discharged from the horizontal cylinder 55 and the through hole 54, that is, the upper discharge port 56 (FIG. 5 (d)).
A closing lid 57 is placed on the outside of the upper discharge port 56 (the through hole 54 of the outer cylinder 53) so that the solidifying agent can be freely released from the upper discharge port 56 (see FIG. 5 (c) (d)). In other words, it is attached to prevent backflow, and prevents clogging of the upper discharge port 56 due to stuffy lumps and the like when the upper discharge port 56 does not operate.

1 rod body 2 fluid path 2a fluid path 3A unit rod 3B unit rod (with upper discharge port)
3C unit rod (with mixing drum)
5 Kneading ram 5 Upper discharge port 7 Closed cylinder (closing tool)
8 upper cylinder rib 9 closed cylinder lower annular rib 11 recess 13 locking device 13 locking device upper operation claw 14 locking device upper operation claw inner edge 16 locking device lower locking device 18 stopper 20 Switch piece (switch tool)
21 large diameter portion 22 of switching piece tapered side 23 of switching piece small diameter portion 25 of switching piece bifurcated portion 30 excavating head 31 excavating head head main body 32 connecting portion 32a of excavating head fluid path 33 fixed excavating head of excavating head head)
35 fluid path 36 drilling arm drilling head 37 drilling head moving drilling blade 40 drilling rod 41 ground 42 pile hole shaft (drilling hole)
42a Lower end 43 of pile hole shaft portion Pile hole enlarged bottom (drilled hole)
43a Bottom of the bottom of the pile hole 43b Bottom of the bottom of the pile hole 45 Bottoming liquid layer (high strength solidifying agent layer, first solidifying agent layer)
46 Pile circumference fixed liquid layer (usually solidifying agent layer, second solidifying agent layer)
51 inner cylinder 52 through hole 53 of the inner cylinder 53 outer cylinder 54 through hole 55 of the outer cylinder connected horizontal cylinder 56 upper discharge port 57 opening / closing lid

Claims (7)

A drilling head is equipped at the lower end of the drilling rod and the drilling hole is drilled, and a solidifying agent is filled in the drilling hole as follows to form a solidifying agent layer in the drilling hole. Solidifying agent into the drilling hole Injection method.
(1) The said drilling rod provided the lower discharge port in the said drilling head, and provided the upper discharge port above the said drilling head.
(2) When the drilling of the drilling hole is completed, a solidifying agent is injected from the lower discharge port to the lower end of the drilling hole to replace the drilling hole residue with the solidifying agent, or the solidifying agent and the inside of the drilling hole Stir and mix the residue.
(3) While pulling up the drilling rod, a solidifying agent is injected from the lower discharge port to a predetermined height of the drilling hole set in advance to form a first solidifying agent layer.
(4) The discharge port is switched from the lower discharge port to the upper discharge port at the predetermined height.
(5) A solidifying agent is injected into the excavated hole from the upper discharge port, and while pulling up the digging rod, the discharged solidifying agent is stirred with the residue in the pile hole to form a second solidifying agent layer.
(6) While performing the operation of (5), the drilling rod is pulled up to the ground to complete the injection of the solidifying agent into the drilling hole. The drilling hole is drilled with the drilling head equipped at the lower end of the drilling rod, and solidifying agent is filled in the drilling hole as follows to form high strength solidifying agent layer and ordinary solidifying agent layer in the drilling hole And injection method of solidifying agent into the wellbore.
(1) The said drilling rod provided the lower discharge port in the said drilling head, and provided the upper discharge port above the said drilling head.
(2) When the drilling of the drilling hole is completed, a solidifying agent is injected from the lower discharge port to the lower end of the drilling hole to replace the drilling hole residue and the solidifying agent, or the solidifying agent and the inside of the drilling hole Stir and mix the residue.
(3) While pulling up the drilling rod, a solidifying agent is injected from the lower discharge port to a predetermined height of the drilling hole set in advance to form a high strength solidifying agent layer.
(4) The discharge port is switched from the lower discharge port to the upper discharge port at the predetermined height.
(5) A solidifying agent is injected into the excavated hole from the upper discharge port, and the solidified solidifying agent layer is formed by stirring the discharged solidifying agent with the residue in the pile hole while pulling up the digging rod.
(6) While performing the operation of (5), the drilling rod is pulled up to the ground to complete the injection of the solidifying agent into the drilling hole. The injection | pouring method of the solidification agent in the pile hole of Claim 1 or Claim 2 comprised as follows.
(1) A kneading drum is disposed below the upper discharge port by a drilling rod, and the solidifying agent is stirred immediately after injecting the solidifying agent from the upper discharge port into the drilling hole while pulling up the drilling rod. Level the hole wall. The method for injecting a solidifying agent into a wellbore according to claim 1 or 2, wherein the method is configured as follows.
(1) Once the lower discharge port reaches the preset depth position, the raising of the digging rod is once stopped.
(2) Close the lower discharge port and open the upper discharge port.
(3) Before or after (2), the drilling rod is moved down or raised to position the upper discharge port near the set depth position, and the solidifying agent is discharged from the upper discharge port. Lower or raise the drilling rod. A drilling rod equipped with a drilling head at the lower end and configured as follows.
(1) A liquid passage for conveying the solidifying agent supplied from the solidifying agent supply device on the ground to the discharge port was formed in the hollow portion of the digging rod.
(2) The lower end of the front fluid passage was connected to the lower discharge port formed in the drilling head.
(3) The upper discharge port is formed at the height position above the drilling head by the digging rod, and the upper discharge port is connected through the branch portion formed in the liquid path.
(4) The upper discharge port was closed by the upper discharge port closure.
(5) The liquid passage can supply the switching tool from above to the branch portion.
(6) When the switching tool reaches the branch portion, the closing of the upper discharge port by the closing tool is released to open the upper discharge port, and the lower discharge port can be closed. The drilling rod according to claim 5, which is configured as follows.
(1) The drilling rod is provided with a kneading drum above the drilling head for kneading the wall of the drilling hole, and an upper discharge port is formed immediately above the kneading drum. A drilling rod equipped with a drilling head at the lower end and configured as follows.
(1) A liquid passage for conveying the solidifying agent supplied from the solidifying agent supply device on the ground to the discharge port was formed in the hollow portion of the digging rod.
(2) The lower end of the front fluid passage was connected to the lower discharge port formed in the drilling head.
(3) The drilling rod is provided with a kneading drum for kneading the drilling hole wall at a height position above the drilling head, and an upper discharge port is formed immediately above the kneading drum.
(4) The upper discharge port is connected through the branch portion formed in the liquid passage.
(5) The upper discharge port is closed by the closing tool of the upper discharge port, and further, the closing by the closing tool is released to open the upper discharge port and the switching tool capable of closing the lower discharge port is provided.

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