JP3179038B2 - Injection rod and ground improvement body construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to improvement of soft ground,
The present invention relates to the formation of a ground improvement body constructed for the purpose of building structure foundations and the like, and more particularly to a structure of an injection rod for excavating the ground and injecting a hardening agent into the ground, and a method of applying the same.

[0002]

2. Description of the Related Art A ground improvement method by spraying a curing agent has been developed through various trials and errors. Tokuhei 8-2
No. 6539 discloses a ground improvement apparatus having an injection rod provided with a stirring blade or a drilling blade. Generally, a plurality of stirring blades or the like in the prior art are provided so as to extend in the direction perpendicular to the injection rod axis near the tip of the injection rod, and the inside of the stirring rod or the like is provided inside the stirring blade or the like. The injection pipe obtained by bending the injection pipe extends, and an injection nozzle is provided at the tip of the blade. At the time of construction, by rotating the agitating blades, etc., and agitating and / or excavating while injecting a hardening agent that is a high-pressure fluid from the tip, it is possible to efficiently and reliably create a large-diameter and tough ground improvement body. It was realized. Where it is preferred to inject the curing agent with water or air, it may be coaxial multiple tubes or parallel multiple tubes.

In Japanese Patent No. 25553423 and JP-A-6-57733, a hardener injection nozzle is provided on the outer wall of an injection rod, and a horizontal blade, which is a stirring blade or a cutting blade, is provided above or below the injection nozzle. An associated injection rod is disclosed.

[0004] In Japanese Patent Publication No. 8-6311, there is disclosed a sludge wing provided horizontally from an injection rod. The mud wing has a slime inlet on its side edge. During construction, the slime in the ground is sucked and discharged to the ground while rotating the wing.

As described above, an injection rod or a drill rod provided with a horizontal wing having various functions has been proposed.
Each contributes to the development of the ground improvement body construction method and its equipment.

[0006]

However, the injection rods and the like provided with the various horizontal wings described above have useful functions themselves, but penetrate the ground into the ground during construction. In addition, there is a problem with the work to be collected after construction.

That is, in order to penetrate a rod provided with a horizontal wing into the ground, a large-diameter hole must first be provided. Drilling large holes with a common drilling rod without wings dedicated to drilling is not efficient. Also, when excavating with a rod having a horizontal excavation wing, it is necessary to proceed while excavating a large-diameter hole with the excavation wing until the target maximum depth is reached from the ground. Such an operation prior to the curing agent injection step imposes a heavy burden on the apparatus and takes time. Further, usually, the portion where the ground improvement body is actually formed is not from the maximum depth to the ground, but from the maximum depth to a predetermined depth. Therefore, digging a large-diameter hole from the ground is useless in terms of energy.

When the rod with the horizontal wings is recovered after the improved body is formed, the borehole is usually filled with mud, so that when the rod is pulled up, the resistance of the wing is large and the load is large. In addition, when the wings are lifted while rotating, the resistance is small, but the load on the device is increased and energy is wasted. In addition, it is necessary to carefully take up the wing so as not to damage the wing, and the wing cannot be quickly recovered.

In view of the above problems, the present invention relates to an injection rod for a ground improvement body forming apparatus, which is capable of efficiently drilling and collecting holes and has a horizontal wing provided with various useful functions. Is to provide a rod. Also,
An object of the present invention is to provide a ground improvement body forming method using an injection rod provided with a horizontal wing, which can efficiently perform drilling and recovery.

[0010]

In order to achieve the above object, a first aspect of the present invention is used for constructing a ground improvement body, and an injection pipe incorporated in a rod body and the rod body. An injection rod having an excavation bit at the lower end of the wing support portion, the wing support portion being provided so as to protrude from the outer periphery of the rod body, and integrally rotating with the rotation of the rod body; and An opening / closing shaft provided, a horizontal wing pivotally supported by the opening / closing shaft and rotatable between a position parallel to the rod body upward and a position parallel to the downward shaft, and the horizontal wing. Holding means in a position perpendicular to the axis of the rod body.

According to a second aspect of the present invention, in the first aspect, the injection rod has one or a plurality of side holes branched from the injection pipe and opened on the outer periphery of the rod body. Means for holding the horizontal wing in a position perpendicular to the axis of the rod body is a piston pipe built in the wing support portion and communicating with the side hole of the injection pipe, and slides in the piston pipe. A piston, the piston having a back surface facing the side hole, and a front surface facing a bearing portion of the horizontal blade supported by the opening / closing shaft, and having a predetermined high pressure in the injection pipe. The horizontal wing is held in a vertical position by moving the horizontal wing when it is received from the rear surface and pressing the bearing portion of the horizontal wing against the opening / closing axis by the front surface so as not to rotate.

According to a third aspect of the present invention, in the second aspect, there is provided a downward orifice at a lower end of the injection pipe, and means for closing the orifice. The injection rod according to claim 2, wherein the predetermined high pressure in the injection pipe is obtained by closing the injection port.

According to a fourth aspect of the present invention, in the third aspect, the means for closing the injection port is a sphere dropped into the injection pipe.

According to a fifth aspect of the present invention, in any one of the above aspects, the wing support portion has a knock pin extending downward from a lower surface thereof, while the rod body is provided below the wing support portion. The wing support portion has a projecting portion from the outer periphery, and when the rod body rotates, the knock pin abuts on and engages the side surface of the projecting portion, whereby the wing support portion rotates integrally with the rod body.

According to a sixth aspect of the present invention, in the above-mentioned fifth aspect, the excavation bit has a flat bit upper end surface, a plurality of blades protruding from the outer periphery of the rod body, and a space between each of these blades. A bit side provided with a concave portion, a protruding portion from the outer periphery of the rod body with which the knock pin abuts and engages is the concave portion of the bit side surface, and the horizontal wing is held in a vertical position. When the horizontal wing is placed on the upper end surface of the bit and the horizontal wing is held at a position parallel to the downward direction, the horizontal wing is accommodated in the recess on the side surface of the bit.

According to a seventh aspect of the present invention, the second to sixth aspects are described.
In any one of the aspects, a delivery path built in the wing support portion and communicating with the side hole of the injection pipe, an injection path built in the horizontal wing and extending from a bearing portion of the horizontal wing to a tip, and the tip An ejection nozzle which is open, and only when the horizontal wing is held in the vertical position, the delivery path in the wing support portion communicates with the injection path and the injection nozzle in the horizontal wing. I do.

According to an eighth aspect of the present invention, there is provided a rod body, an injection pipe built in the rod body, a means for injecting the curing agent in the injection pipe in a horizontal direction, and excavation at a lower end of the rod body. A bit, a wing support portion provided so as to protrude from the outer periphery of the rod body and integrally rotated with the rotation of the rod body, an opening / closing shaft provided on the wing support portion, and the opening / closing shaft. A horizontal wing that is pivotally supported and rotatable between a position parallel to the axis of the rod body upward and a position parallel to the downward direction, and a position perpendicular to the axis of the rod body. Soil improvement method using an injection rod having means for holding the rod body while rotating the rod body in a state where the horizontal wings are in a position parallel to the axis of the rod body in an upward direction. Drilling the ground with the drill bit Drilling more to the first depth, while rotating the rod body, pulling up the rod body until the horizontal wing rotates about the opening / closing axis and reaches a position perpendicular to the axis of the rod body, The ground is held by holding the horizontal wing in the vertical position and raising the rod to a second depth while injecting the hardener horizontally while rotating the rod integrally with the horizontal wing. While improving the rod body, while rotating the rod body in the opposite direction, the horizontal wing is pivoted about the opening / closing axis, and the rod body is pulled up to a position parallel to the axis of the rod body downward. After the horizontal wings are at the position parallel to the downward direction, the rod body is recovered.

According to a ninth aspect of the present invention, in the above-mentioned eighth aspect, the fact that the horizontal wing is located at a position perpendicular to the axis of the rod body detects the rotation load of the rod body. Confirm by doing

According to a tenth aspect of the present invention, in the eighth or ninth aspect, in the step of forming the ground improvement body by injecting the hardening agent in a horizontal direction, the hardening agent is applied to the tip of the horizontal blade. Inject from

[0020]

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described mainly with reference to the drawings with reference to preferred embodiments. A preferred example is an injection rod having a stirring blade having a curing agent injection function,
The present invention is not limited to the stirring blade alone, and is applicable to an injection rod provided with a horizontal blade having various functions regardless of the presence or absence of the injection function.

In this specification, a ground improvement method in which a hole is drilled vertically downward from the ground will be described as an example. For convenience, the leading end side of a pouring rod with a drill bit is referred to as “downward”. Although the opposite side is referred to as “upper”, it will be apparent from the following description that the present invention is applicable to a method of drilling in an oblique direction.

FIG. 1 is an external view showing an external appearance of a main part of a preferred embodiment of an injection rod 10 according to the present invention and a state of use in a method using the same. FIG. 1 is a diagram showing a portion near the lower end of the injection rod 10. Injection rod 10
Is included in the ground improvement device (not shown),
Rod body 12 and injection pipe 12 built in rod body 12
a, and a drill bit 24 provided at a lower end of the rod body 12. Further, the injection rod 10 in FIG. 1 includes a pair of agitating blades 16 each having an injection nozzle 28 for injecting a curing agent at a tip. One of the features of the injection rod of the present invention is a mechanism for attaching the stirring blade 16 to the rod body 12. FIG. 1A shows a state in which the body is descending while drilling, FIG. 1B shows a state in which the body is rising while forming a ground improvement body by spraying a hardening agent, and FIG. (C)
Shows the injection rod 10 in a state where the injection rod 10 is being pulled up for recovery after the end of the curing agent injection. in this way,
In each step, the position of the stirring blade 16 can be changed to a position parallel to the axis of the rod body 12 upward, a position perpendicular to the axis of the rod body 12, and a position parallel to the axis of the rod body 12 downward. .

On the outer periphery of the rod body 10 shown in FIG.
A plate-like wing support portion 20 extending horizontally is provided. In this example, the wing support 20 is placed on the upper end surface 24 a of the drill bit 24. The blade support portion 20 includes a pair of opening / closing shafts 18 for attaching the pair of stirring blades 16 symmetrically with respect to the rod body. A bearing portion is provided at the base of the stirring blade 16 and is supported by an opening / closing shaft 18. FIG.
(A) is a state in which the rod body 12 is rotated in the direction of the arrow, that is, while the drill bit 24 is being rotated to make a hole and descend in the ground. At the tip of the rod body 12, there is a high-pressure water injection port 25 for efficiently drilling while injecting high-pressure water. At this time, the stirring blade 16 is
It is closed with its tip facing up parallel to the second axis.

A knock pin 26 is provided on the lower surface of the wing support portion 20 so as to protrude downward. In this state, the knock pin 26 abuts on a bit side surface 24 b having a blade 24 d on the side surface of the excavation bit 24 as an edge. I agree. Since the drill bit 24 is rotating in the direction of the arrow, the bit side 2
4b pushes the knock pin 26 so that the wing support 20
Is rotated integrally with the rod body 12. A fixing ring 22 is provided on the wing support 20. In this example, the wing support portion 20 can be attached and detached by inserting and removing it from the rod body 12. The fixing ring 22 is for fixing the position of the wing support 20 in the vertical direction. Drilling is performed up to a predetermined maximum depth.

In FIG. 1B, after the drilling is completed after reaching the predetermined maximum depth, the stirring blade 16 is rotated by 90 degrees about the opening / closing shaft 18 from the position of FIG. Orients perpendicular to the axis. A method for rotating the stirring blade 16 will be described later. After the stirring blade 16 is in a horizontal state as described above, the hardener 40 is injected and injected. That is, the injection rod 10 is raised at a predetermined speed while the stirring blade 16 is rotated integrally with the rod body 12 and the hardener 40 is injected at a high pressure from the injection nozzle 28 at the tip of the stirring blade 16.
Also at this time, when the knock pin 26 is pushed by the bit side surface 24b, the stirring blade 16 rotates integrally with the rod body 12. When the injection rod 10 rises to a predetermined depth corresponding to the upper end of the ground improvement body to be created, the injection of the curing agent 40 is completed. The stirring blade 16 in this example mainly has a stirring function. However, if a bit is appropriately provided, the excavating function is strengthened, and the efficiency is further improved.

In FIG. 1C, after the injection of the curing agent 40 is completed, the stirring blade 16 is further rotated by 90 degrees about the opening / closing shaft 18 from the position shown in FIG. Close with the face down. At the time of this operation and at the time of subsequent recovery, the rod body 12 is rotated in the opposite direction as before, as indicated by the arrow. Accordingly, the knock pin 26 is pushed by the bit side surface 24c, so that the wing support portion 20 can rotate integrally with the rod body 12.

In the example shown in FIG. 1, the surface of the concave portion between the blades 24d of the excavation bit 24 is used as the surface which comes into contact with the knock pin 26, but the same function is provided on the outer periphery of the rod body 12. May be separately provided. However, when the drill bit 24 is used as in the example of FIG.
In the state of (B), the stirring blade 16 can be stably supported by the upper end surface 24a of the drill bit 24, and in the state of (C), the stirring blade 16 can be accommodated in the side recess of the drill bit 24. It is preferable because it can be performed.

As shown in FIG. 1, the injection rod 10 according to the present invention has a mechanism for opening and closing a stirring blade 16 rotatable integrally with the rod body 12. Thereby, the stirring blade 16
The substantial diameter of the injection rod 10 at the time of the excavation (A) and the recovery at the time (C) is significantly smaller than that at the time of the injection (B) with the stirring blade 16 opened. As a result, the excavation and recovery of the injection rod 10
It can be executed very smoothly and quickly.

FIG. 2 is an exploded perspective view of the injection rod 10 of FIG. The rod body 12 provided with the excavation bit 24 at the lower end is attached to the blade support 2 to which the stirring blade 16 is rotatably attached.
The injection rod 10 is assembled by passing through the through-hole 20a and the fixing ring 22 and fixing the same. On the outer periphery of the rod body 12 corresponding to the position where the wing support portion 20 is placed, a side hole 50 and an O-ring 30 as a sealing material thereof are provided. As will be described later in detail, the side hole 50 is a pipe that is branched in the horizontal direction from the injection pipe 12a built in the rod body 12, and
2 is open on the outer periphery.

FIG. 3 shows the injection rod 1 of FIG. 1 according to the invention.
It is the figure which showed typically an example of the ground improvement body construction method using 0. In FIG. 3A, the drilling bit 24 drills a hole up to the target maximum depth 6 while rotating the rod body 12 in the direction of arrow 2. At this time, the stirring blade 16 is closed, and its tip is directed upward. The substantial diameter of the injection rod 10 in this state falls within the range of the diameter of the drill bit 24, and the drilling is performed smoothly. In FIG. 3B, after the tip of the excavation bit 24 reaches the maximum depth 6, the rod body 12 is rotated in the direction of arrow 2 while applying a force to lift the rod body 12 upward.

FIG. 4 is a diagram showing the state of FIG. 3B in more detail. When the rod 13 is rotated while pulling upward from the state of FIG.
As shown in FIG. 4 (II), the tip of the stirring blade 16 along the rod body is gradually opened by being caught on the ground,
In addition, since the stirring blade 16 is also rotating, it gradually opens in the horizontal direction while excavating the obstructed ground. Figure 4 (II
When the stirring blade 16 is horizontal as shown in FIG.
As shown in (B), it is mounted on the upper end surface of the excavation bit 24 and does not lower further. Thus, the stirring blade 16 is opened horizontally. This state is confirmed by detecting the load of the rotational torque.

Thereafter, as shown in FIG. 3C, injection of the curing agent 40 from the tip of the stirring blade 16 is started, and the rod 1
2 is rotated at a predetermined speed while rotating in the direction of arrow 2. Thus, the ground improvement body 42 is formed. FIG.
In (D), the ground improvement body 42 is formed to a predetermined depth 8, and after the injection of the hardener 40 is stopped, the rod body 12 is pulled upward and rotated in the direction of arrow 4 in the opposite direction. Then, the stirring blade 16 moves off the upper end surface of the drill bit 24 and moves onto the concave portion on the side surface (FIGS. 1B and 1C).
reference). If the rotation and the upward pulling are further continued in this state, the stirring blade 16 gradually closes downward and finally closes completely along the rod body 12.
After the stirring blade 16 is closed in this way, the rod body 12 is lifted upward while being rotated in the direction of arrow 4 and collected.

FIG. 5 is a schematic partial cross-sectional view of the vicinity of the mounting portion of the stirring blade 16 in the injection rod 10 of FIG.
A mechanism for holding the stirring blade 16 in the horizontal direction and a mechanism for sending the curing agent to the tip of the stirring blade 16 are shown.

The injection pipe 12a is provided with a plurality of side holes 50, 51, etc., which are branch paths in the horizontal direction, at positions corresponding to locations where the stirring blades 16 are attached.
51 and the like are opened on the outer periphery of the rod body 12, and these openings are covered by the wing support portion 20 penetrating therethrough. The opening of the side hole 50 in FIG.
It communicates with a piston pipe 32 that is built in radially at zero. A piston 52 is slidably provided in the piston tube 32. The front surface of the piston 52 faces the base of the stirring blade 16, that is, the bearing 16 a with a slight gap therebetween. FIG.
(A) is a state in which the stirring blade 16 after drilling is completed is still closed upward. At this time, the high pressure water injection port at the tip of the injection pipe 12a is open, and the inside of the injection pipe 12a is in a low pressure state. Then, the stirring blade 16 is opened in the horizontal direction as described above. After confirming that the stirring blade 16 has been opened horizontally,
By dropping the sphere 59 into the injection pipe 12a as shown in FIG. 5B, the high-pressure water injection port 25 is closed, and the internal pressure of the pipe is increased to a predetermined pressure. Then, the back surface of the piston 52 in the piston pipe 32 is pushed as shown in FIG.
The piston 52 moves toward the bearing portion 16a, and the front surface of the piston 52 abuts against the bearing portion 16a and presses the bearing against the opening / closing shaft 18 so that rotation is impossible. Thus, the stirring blade 16 is held in the horizontal direction.

On the other hand, the side hole 5 of the injection pipe 12a shown in FIG.
Reference numeral 0 denotes a delivery pipe (reference numeral 5 in FIG. 6) built in the wing support portion 20.
3, 54 and 55) in the shaft 18. A delivery port 57 for delivering a fluid to the stirring blade 16 is provided on the delivery pipe 55 of the shaft 18. The stirring blade 16 has
Although the injection path 58 extending from the bearing portion to the tip is built in, when the stirring blade 16 is not horizontal, the injection path 58 built in the stirring blade 16 and the outlet 57 of the shaft 18 are disconnected. ing. When the stirring blade 16 is in a horizontal state as shown in FIGS. 5B and 5C, the injection path 58 and the outlet 57 communicate with each other, and the fluid from the injection pipe 12 a can reach the tip of the stirring blade 16. Becomes As shown in FIG. 5C, a high-pressure fluid is ejected from the tip of the stirring blade 16 in a state where the pipe internal pressure is high.

FIG. 6 is a schematic plan view of FIG. The piston 52 presses and holds the base of the stirring blade 16, and at this time, the curing agent in the injection pipe 12 a
From the delivery pipes 53, 54 and 55 in the wing support 20;
Then, it is sent to the injection path 58 in the stirring blade 16 via the outlet 57.

The embodiment described above is one of the simplest ones. In another embodiment, water or air may be jetted together with the curing agent by using multiple or multiple injection tubes. Further, the pressure medium for operating the piston 52 of FIG. 5 may be sent out by another pipe. Further, the mechanism for holding the stirring blade in the horizontal direction may be a mechanical lock mechanism. Further, the mechanism in which the fluid is delivered only when the stirring blade is in the horizontal state and not delivered in other states is not limited to the example described above.

In particular, the illustrated mechanism and method for opening and closing the stirring blade can be applied to a stirring blade, a drilling blade, or a drainage blade having no injection function, and any of them can improve the construction efficiency. .

[0040]

According to the injection rod provided with the horizontal wing and the ground improvement body construction method using the same according to the present invention, the horizontal wing is closed in parallel with the rod body at the time of drilling and recovery, and At the time of development, it can be opened horizontally,
Drilling and recovery can be performed smoothly and quickly, and in the ground, it is possible to construct an improved body using various useful functions of the horizontal wing. In particular, the injection rod and the construction method according to the present invention are very useful for improving soft ground. That is, a relatively hard surface layer can be efficiently drilled, and the horizontal blade can be smoothly opened and closed by the horizontal blade opening and closing mechanism in the target soft ground layer.
As described above, the present invention solves the problems of the injection rod provided with the horizontal wings having various functions and the method of manufacturing the same, and allows the useful functions to be sufficiently exerted, and greatly contributes to its practical use.

[Brief description of the drawings]

FIG. 1 is an external view showing an external appearance of a main part of a preferred example of an injection rod according to the present invention and a use state in a construction method using the same.

FIG. 2 is a developed perspective view of the injection rod of FIG.

FIG. 3 is a view schematically showing an example of a ground improvement body forming method using the injection rod of FIG.

FIG. 4 is a diagram showing the state of FIG. 3B in more detail.

FIG. 5 is a schematic partial cross-sectional view of the vicinity of a mounting portion of a stirring blade in the injection rod of FIG. 1;

FIG. 6 is a schematic plan view of FIG. 5 (C).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Injection rod 12 Rod body 16 Horizontal wing 16a Horizontal wing bearing part 18 Opening / closing axis 20 Blade support part 22 Fixing ring 24 Drilling bit 24a Drilling bit upper end face 24b, 24c Drilling bit side face 24d Drilling bit cutting edge 25 High-pressure water jet 26 Knock pin 28 Injection nozzle 30 O-ring for blade support 32 Piston pipe 40 Hardening agent 42 Ground improvement body 50,51 Injection pipe side hole 52 Piston 53,54,55,56 Delivery path 57 Delivery outlet 58 Injection path 100 Ground

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-107714 (JP, A) JP-A-61-50127 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/12

Claims (10)

(57) [Claims] 1. An injection rod used for forming a ground improvement body and having an injection pipe built in the rod body and a drill bit at a lower end of the rod body, wherein the injection rod projects from an outer periphery of the rod body. A wing support portion provided and rotated integrally with the rotation of the rod body; an opening / closing shaft provided on the wing support portion; and an opening / closing shaft supported by the opening / closing shaft and with respect to the axis of the rod body. A horizontal wing rotatable between a position parallel to the upper side and a position parallel to the lower side, and means for holding the horizontal wing in a position perpendicular to the axis of the rod body. Injection rod in the ground improvement body preparation device to do. 2. The injection rod has one or a plurality of side holes branched from the injection pipe and opened on the outer periphery of the rod body, and the horizontal wing is perpendicular to an axis of the rod body. Means for holding the piston at a proper position, the piston having a piston pipe built in the wing support portion and communicating with the side hole of the injection pipe, and a piston sliding in the piston pipe. A front surface facing a bearing portion of the horizontal wing that is supported by the opening / closing shaft, and moves when receiving a predetermined high pressure in the injection pipe from the rear surface, and moves by the front surface. The injection rod according to claim 1, wherein the horizontal wing is held at a vertical position by pressing a bearing portion of the horizontal wing against the opening / closing shaft so as not to rotate. 3. An injection port having a downward orifice at a lower end of the injection pipe and means for closing the orifice, wherein the orifice is closed by means for closing the orifice. The injection rod according to claim 2, wherein the predetermined high pressure in the injection tube is obtained. 4. The injection rod according to claim 3, wherein the means for closing the injection port is a sphere dropped into the injection pipe. 5. The wing support has a knock pin extending downward from a lower surface of the wing support, while the rod body has a protruding portion from the outer periphery below the wing support,
5. The wing support section rotates integrally with the rod body by the knock pin abuttingly engaging the side surface of the overhang portion when the rod body rotates. The injection rod as described. 6. The drill bit has a flat bit upper end surface, a plurality of blades protruding from the outer periphery of the rod body, and a bit side surface provided with a concave portion between each of the blades. The protruding portion from the outer periphery of the rod body to be in abutting engagement is the concave portion on the side surface of the bit, and when the horizontal wing is held in a vertical position, the horizontal wing is positioned on the upper end surface of the bit. The injection rod according to claim 5, wherein when the horizontal wing is mounted and held in a position parallel to the downward direction, the horizontal wing is housed in the recess on the side surface of the bit. 7. A delivery path which is built in the wing support portion and communicates with the side hole of the injection pipe, an injection passage which is built in the horizontal wing and extends from a bearing portion of the horizontal wing to a tip, and is opened at the tip. Having an injection nozzle, only when the horizontal wing is held in the vertical position,
The injection rod according to any one of claims 2 to 6, wherein the delivery path in the wing support section communicates with the injection path and the injection nozzle in the horizontal wing. 8. A rod body, an injection pipe built in the rod body, means for horizontally injecting a curing agent in the injection pipe, a drill bit at a lower end of the rod body, A wing support portion extending from the outer periphery and integrally rotating with the rotation of the rod body, an open / close shaft provided on the wing support portion, and the rod body supported by the open / close shaft and supported by the open / close shaft; A horizontal wing rotatable between a position parallel to the axis upward and a position parallel to the bottom downward, and means for holding the horizontal wing in a position perpendicular to the axis of the rod body. A ground improvement body forming method using an injection rod, wherein the horizontal wing is set in a position parallel to an axis of the rod body in an upward direction, and the ground is dug by the drill bit while rotating the rod body. To the first depth Drilling, while rotating the rod body, pulling up the rod body until the horizontal wing rotates about the opening / closing axis to a position perpendicular to the axis of the rod body, Holding the position, forming the ground improvement body by raising the rod body to a second depth while injecting the hardener horizontally while rotating the rod body integrally with the horizontal wing, While rotating the rod body in the opposite direction, the horizontal wing is pivoted about the opening / closing axis and lifts up the rod body until it becomes a position parallel to the axis of the rod body downward, and the horizontal wing faces the downward. And then recovering the rod body after reaching a position parallel to the ground. 9. The system according to claim 8, wherein the position of the horizontal wing perpendicular to the axis of the rod body is confirmed by detecting a rotation load of the rod body.
Ground improvement body construction method described in 1. 10. The ground according to claim 8, wherein, in the step of forming the ground improvement body by injecting the hardener in the horizontal direction, the hardener is injected from a tip of the horizontal blade. Improved body construction method.