JP3323478B2 - Ground improvement device and improvement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for improving ground.

[0002]

2. Description of the Related Art As a method of improving the ground, a method of stirring and mixing while cutting the ground where grout such as cement milk is injected at a high pressure at a high pressure, a method of entraining air at that time, and a method of jetting a high pressure water at a high pressure. And a method of stirring and mixing the cut earth and grout with the grout, etc., are widely used.

[0003] In any case, in this type of construction method, a relatively large amount of sludge is generated, and its treatment is required.

Recently, there has been an increasing demand for soil improvement technology at large depths. For example, if an improvement rod is inserted horizontally from a shaft into a position under pressure of groundwater to improve the ground, However, since the groundwater including mud flows backward and gushes through the improvement rod, it is difficult to improve the groundwater under pressure.

Therefore, one of the applicants of the present invention has previously described Patent No. 26
No. 47572 discloses that a sludge pipe is inserted in parallel with a grout injection pipe and sludge is discharged while controlling the amount of sludge through the sludge pipe.

[0006]

However, the structure of the exhaust pipe and the manner of installation thereof are not described in detail in the above patent. There is a slight disclosure about opening and closing the suction port (discharge port) of the discharge pipe.

[0007] However, it has been found that the structure of the exhaust pipe is important when actually performing the construction. That is, as means for opening and closing the water suction port (drainage port) of the drainage pipe, there is a means for switching the flow path by, for example, inserting a ball in the case of a vertical orientation, but in a horizontal state, the ball is caused by gravity. You cannot take this measure because it does not fall. It is possible to provide a piston for opening and closing a water suction port (discharge port) at the tip, but this is not realistic because it increases the diameter of the discharge pipe. Thus, the inability to find a means for reliably and easily opening and closing the water suction port (discharge port) of the discharge pipe has been an obstacle to actual construction.

[0008] On the other hand, in the improvement of groundwater under pressure,
Muddy groundwater can flow back from the nozzle of the improved rod, and there is a risk of clogging and damage to the nozzle.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a ground improvement device capable of reliably switching communication between an opening window and an inner pipe in a ground insertion pipe such as a drain pipe or an improved rod. is there.

Another object of the present invention is to ensure a reliable construction in the improvement of a groundwater under pressure.

[0011]

The present invention which has solved the above-mentioned problems is as follows. <Invention according to claim 1> An insertion pipe in which the inner pipe and the outer pipe are substantially concentrically assembled is inserted into the ground, and the base of the insertion pipe is installed outside the ground.
It is configured to flow a target fluid between the base and the distal end of the insertion tube, and an opening window is formed in a wall surface of the distal end of the outer tube, and the inner window and the opening window are formed at the distal end of the inner tube. Are configured to be able to communicate with each other, and in a state where the position of the outer tube is fixed, the inner tube can be moved in the axial direction by an external force applied to the inner tube at the base portion. communication between the inner tube and opening window is blocked, is configured to communicate with the opening window and the inner tube in the second position is achieved, wherein the insertion tube inner tube and communicates with its interior A ground improvement fluid ejection nozzle is disposed facing outward and the ejection nozzle is disposed in the first position.
The improvement of the ground, wherein the jet nozzle faces the opening window and the fluid for soil improvement is jetted from the jet nozzle in a state in which the chisel is hidden by the outer tube and the second position is taken. apparatus.

(Function and Effect) A. An opening window is formed in a wall surface of a distal end portion of the outer tube, and the inside of the inner tube and the opening window are configured to be able to communicate with each other at a distal end portion of the inner tube. When the inner tube is configured to be movable in the axial direction by an external force acting on
The communication between the opening window and the inside of the inner tube can be prevented at the position (2), and the communication between the opening window and the inside of the inner tube can be achieved at the second position. By configuring the inner tube to move in the axial direction with an external force acting on the inner tube at the base of the insertion tube in this manner, opening and closing of the opening window and communication and stop of the inner tube become possible. , Reliable operation is promised. Then, even if the insertion tube is installed horizontally, the operation can be reliably performed. B. Using the insertion tube as an improved rod, this improved rod
Ground improvement material such as cement milk into the ground
Nozzle for jetting or jetting high-pressure water
When equipped, groundwater mixed with mud flows back from the nozzle
May cause clogging and damage to the nozzle.
Danger. Therefore, according to the present invention, the first
When the position is taken, the ejection nozzle is hidden in the outer tube.
And the risk described above is completely eliminated. Also,
When the second position is taken at a constant depth, the ejection nozzle
Can face the opening window, and in this state,
The ground improvement fluid (cement milk or water)
Etc.).

<Invention according to claim 2> An insertion pipe in which an inner pipe and an outer pipe are substantially concentrically assembled is inserted into the ground, and the base of the insertion pipe is installed outside the ground, and the base is connected to the base. It is configured to flow the target fluid between the distal end of the insertion tube, an opening window is formed in the distal end wall surface of the outer tube,
At the tip of the inner tube, the inside of the inner tube and the opening window are configured to be able to communicate with each other, and in a position fixed state of the outer tube, the inner tube is axially moved by an external force acting on the inner tube at the base. It is made movable so that communication between the opening window and the inside of the inner tube is prevented at a first position of the movement, and communication between the opening window and the inside of the inner tube is achieved at a second position. Equipment; ground improvement rod
When inserted into the ground and in the first position, the inner pipe
And drilling water from the tip side through the opening window
While improving the ground while drilling to the specified depth
Substantially parallel to the rod,
Insert the insertion tube toward a good area;
Discharge the ground improvement material into the ground through a good rod,
The mud accompanying the discharge of the ground improvement material into the ground
In the state of taking the position of 2, from the ground side from the opening window
A method for improving the ground , wherein a fluid is guided toward the base and discharged out of the ground.

(Function and Effect) When it is desired to insert a hole in the insertion pipe itself instead of drilling the casing, when the first position is adopted, communication between the opening window and the inside of the inner pipe is prevented. no but intrude, it is possible to perform drilling and pumping drilling water through the inner tube in this state
You. D. As in the above-mentioned patent method, a ground improvement rod is inserted into the ground, a ground improvement material such as cement milk is discharged into the ground through the ground improvement rod, and the ground improvement rod and the ground improvement area are moved toward the ground improvement area. Insert the insertion pipe substantially in parallel, guide the mud accompanying the discharge of the ground improvement material into the ground, in the state where the second position is taken, from the opening window to the base side, out of the ground When taking the form of discharging, the insertion pipe of the present invention can be effectively used as a drainage pipe.

<Invention according to claim 3> An insertion pipe in which an inner pipe and an outer pipe are assembled substantially concentrically is inserted into the ground, and the base of the insertion pipe is installed outside the ground,
It is configured to flow a target fluid between the base and the distal end of the insertion tube, and an opening window is formed in a wall surface of the distal end of the outer tube, and the inner window and the opening window are formed at the distal end of the inner tube. Are configured to be able to communicate with each other, and in a state where the position of the outer tube is fixed, the inner tube can be moved in the axial direction by an external force applied to the inner tube at the base portion. An improved device configured to prevent communication between the opening window and the inside of the inner tube and to achieve communication between the opening window and the inside of the inner tube at a second position is used; A ground improvement fluid ejection nozzle communicating with the inside is provided facing outward, and the insertion pipe is inserted into the ground while taking the first position and hiding the ejection nozzle in an outer pipe. Take the second position at depth and open the jet nozzle In a state in which to face the window, an improved method of the ground which is characterized in that the ground improvement work to discharge into the ground of ground improvement materials include ejection of ground improvement fluid from the spray nozzle.

[0016] (Operation and Effect) E. Using the insertion tube as an improved rod, this improved rod
Ground improvement material such as cement milk into the ground
Nozzle for jetting or jetting high-pressure water
When equipped, groundwater mixed with soil flows backward from the nozzle
May cause clogging and damage to the nozzle.
Danger. Therefore, according to the present invention, the first
When the position is taken, the ejection nozzle is hidden in the outer tube.
And the risk described above is completely eliminated. Also,
When the second position is taken at a constant depth, the ejection nozzle
To the opening window, and in this state,
The ground improvement fluid (cement milk or water)
Etc.).

<Invention according to claim 4> When the insertion pipe is inserted into the ground, when the insertion pipe is at the first position, drilling water is pumped through the inner pipe and discharged from the tip side from the opening window. 4. The method for improving a ground according to claim 3, wherein the insertion pipe is inserted into the ground by drilling a hole to a predetermined depth while the hole is being made.

(Function and Effect) When the insertion pipe is inserted into the ground, a configuration in which drilling water is discharged from the distal end side from the opening window will simplify the flow path configuration of the insertion pipe.

[0019]

[0020]

[0021]

[0022]

[0023]

Embodiments of the present invention will be described below in more detail with reference to the drawings. FIG. 1 shows an installation form of the insertion tube of the present invention. In the illustrated embodiment, a shaft is excavated in the ground G, and is fixed to a pile 91 by, for example, sheet piles 91. Ground G
The improved rod 80 and the drainage pipe 70 are inserted horizontally from the shaft to the position under the groundwater under the groundwater level. As the “insertion pipe” of the present invention, the improved rod 80 and / or the drainage pipe 70 correspond.

The structure of the improved rod 80 will be exemplified later.
A curable material such as cement milk, a ground improvement fluid such as water or air is supplied from the base head 81, and is ejected at a high pressure from a nozzle 82 attached to the tip, and is pulled out while rotating the improvement rod 80 around the axis. Thus, the improved body 100 is formed around the improved rod 80.

At this time, mixed slime of the ground improvement material and the earth and sand particles is generated and becomes mud, and it is necessary to discharge the mud. When the mud is required, the mud accompanying the discharge of the ground improving material into the ground is discharged by the mud pipe 70 inserted substantially parallel to the improvement rod 80 toward the ground improvement area (area of the improved body 100). Through the opening window 52a to discharge the mud outside the ground. When draining, the drain pipe 7
The suction pump 92 is connected to the inner pipe of the pipe 0, and the mud R is discharged by the suction force, and is temporarily stored in the drain pit 93 or the like.

As described above, the "insertion pipe" of the present invention corresponds to the improvement rod 80 and / or the sludge pipe 70. The ground improvement fluid flows between the base and the tip of the insertion pipe. In the case of the drainage pipe 70, there are water for drilling at the time of insertion and mud for drainage. In the case of the improved rod 80, water for drilling at the time of insertion, high-pressure grout, air for promoting sludge or mixing, high-pressure water for ground agitation, and the like correspond to the selection of the construction method.

Therefore, the description will be made separately for the case of the sludge pipe 70 and the case of the improved rod 80. The base head can be used in common.

<Form when the "insertion pipe" is the drainage pipe 70>
2 shows the base head, FIGS. 3 and 4 show the intermediate unit pipe,
6 to 9 each show the tip device, but are shown on a different scale. In the device of the embodiment, the inner tube is movable in the axial direction.

Referring first to FIG. 2, a base inner tube 1 and a base outer tube 2 constituting a base head are assembled concentrically with a gap therebetween. A first swivel 3 is provided at the base of the base inner tube 1 and is rotatably held by bearings 4 and 4. 5A is a sealing material.

A second swivel 6 is provided at the base of the base outer tube 2, and is rotatably held by bearings 7, 7. The base outer surface of the base outer tube 2 is sealed with a sealing material 5B. Further, a seal with the outer surface of the base inner tube 1 is sealed with a sealant 5C in relation to a second flow path inlet P2 formed on the wall of the second swivel 6.

The distal end of the base outer tube 2 and the distal end of the base inner tube 1 are connected with the connecting screw 8 through the distal end wall surface of the base outer tube 2.
The base outer tube 2 and the base inner tube 1 are fixedly connected in the circumferential direction by being fitted in a concave groove 1a formed on the outer surface of the distal end portion of the base inner tube 1 along the axial direction.

On the other hand, the return hydraulic piston 9 is connected to the flange 3A of the first swivel 3 with the flange 6A of the second swivel 6 as a seat. Thus, when the hydraulic piston 9 is extended, the base inner tube 1 and the inner tube group of each unit tube connected to the distal end side move rightward from the state shown in the figure, and move leftward when contracted. Also, in order to ensure the operation of the base inner tube 1 (including the inner tube group on the distal end side) by the hydraulic piston 9, a spring 9b is provided between the nut 9a at the rod end of the hydraulic piston 9 and the flange 3A. It is interposed.

At the base of the base inner tube 1, a first flow path inlet P1 is provided.
Is connected to a hose or the like, and the first fluid X flows in or out (discharges). The second fluid Y flows in or out (discharges) through the second flow path inlet P2 formed in the wall of the second swivel 6.

In the illustrated embodiment, a male screw is formed on the outer surface of the distal end of the base outer tube 2, and a male screw is formed on the outer surface of the distal end of the base inner tube 1.

Next, paying attention to the unit tube Z shown in FIGS. 3 and 4, the inner tube 10 and the outer tube 20 are assembled concentrically with a gap. Although the illustrated inner tube 10 and outer tube 20 are connected to each other, they are illustrated by common hatching so that the distinction between the inner tube 10 and the outer tube 20 becomes clearer.

The inner pipe 10 is a piece as an inlet pipe 11,
It has an intermediate pipe 12 and an outlet pipe 13. The outer tube 20 has, as pieces, a main tube 21, a tip tube 22, and a support tube 23. Numeral 30 is a spacer for keeping concentricity.
0a.

The inlet pipe 11 and the intermediate pipe 12 are screwed together and integrated by a pin 31. Similarly, the intermediate pipe 12 and the outlet pipe 13 are screwed together,
The pins 31 are integrated. A female screw 10F is provided on the inner surface of the inlet pipe 11, and a male screw 10M is provided on the outer surface of the outlet pipe 13.
Are formed respectively.

The main tube 21 and the tip tube 22 are connected by screwing. A support tube 23 is provided to apply a torque applied to the base inner tube 1 from the outer tube 20 to the inner tube 10. Since the support tube 23 is engaged with the right side of the tip tube 22 on the left side thereof in a saw-tooth shape over the entire circumference, the rotation torque is transmitted to the support tube 23 when the outer tube 20 rotates. Referring also to FIG. 4, the inner surface of the support tube 23 has a square surface, and the outer surface of the inner tube 10, specifically, the outer surface of the intermediate tube 12 has a square surface. Accordingly, the rotational torque transmitted to the support pipe 23 is transmitted to the intermediate pipe 12 and consequently the entire inner pipe 10. The support tube 23 has a communication hole 23a. A female screw 20F is formed on the inner surface of the main body tube 21 and a male screw 20M is formed on the outer surface of the tip tube 22.

Here, the female screw 10F, the male screw 10M, the female screw 20F, and the male screw 20M have the same pitch.

After the unit tube Z already connected is disconnected from the base head of FIG. 1, the unit tube Z is brought into the rear part of the unit tube Z already connected, After the connection with the base head is performed in a state where the rotation of the new unit tube Z in the circumferential direction is fixed, the front end of the new unit tube Z is connected to the rear portion of the already connected unit tube Z.

That is, the external thread 10M of the inner pipe 10 of the one unit pipe (new unit pipe Z) and the internal thread 10F of the inner pipe of the other unit pipe (connected unit pipe Z) are connected together with the one pipe. Screw 20M of outer tube 20 of unit tube (new unit tube Z)
And external thread 2 of the outer pipe of the other unit pipe (connected unit pipe Z)
OF are simultaneously screw-connected.

Next, a state-of-the-art unit pipe Z shown in FIGS.
A description will be given of the tip device Q that is screwed and connected to the device. In the illustrated distal end device Q, the inner pipe 40 and the outer pipe 50 are assembled concentrically with a gap and connected in a circumferentially stationary manner on the same principle as the unit pipe Z. Although the illustrated inner tube 40 and outer tube 50 are connected to each other, they are illustrated by common hatching so that the distinction between the inner tube 40 and the outer tube 50 can be made clearer. On the other hand, a flow channel monitor 60 is provided at the tip.

The outer tube 50 has an inlet tube 51, an intermediate tube 52, an outlet tube 53 and an inner tube 54. The intermediate pipe 52 has an oval-shaped through-hole 52a at two locations in the circumferential direction.
If necessary, a blocking plate 52b for preventing intrusion of pebbles into the inside is provided. The position where the through hole 52a is formed is 90
A through hole 52c is formed at a position deviated in the circumferential direction. The through hole 52c communicates with a gap between the inner tube 40 and the outer tube 50.

Through the gap between the inner pipe 40 and the outer pipe 50 and the through hole 52c, for example, water W is guided to the guide path of the main body 61 of the flow path monitor 60, and further from the nozzle 62a of the nozzle body 62 connected to the main body 61. It is designed to promote ejection of mud R by spouting.

In order to send drilling water DW used for drilling into the ground through the inner pipe 40, a guide hole is formed in another part of the main body 61, and is sent into the attachment 63 through this guide hole to form the nozzle body. The nozzles are ejected from 64 nozzles 64a.

At the time of drilling / inserting the ground by the mud pipe 70, the inner pipe 40 is at the position where it is pushed down as shown in FIGS. 6 and 7, and in this state the drilling water DW is pumped through the inner pipe 40. Is done.

When the drainage pipe 70 reaches a predetermined depth and needs to be drained, the inner pipe 40 is pulled up as shown in FIGS. Thus, the through-hole 52a directly faces the outside. The suction force of the suction pump 92 is given to the inner pipe 40 as described with reference to FIG.
The mud R is drained. Mud R may be discharged naturally by pressure from the ground without using the suction pump 92.

As described above, by moving the inner head of the base head, the group of unit tubes Z, and the inner tube of the tip device Q, the through-hole 5 is formed.
2a is opened and closed. The through-hole 52a needs to be closed in order to prevent the intrusion of the surrounding earth and sand at the time of drilling / inserting the ground by the exhaust pipe 70.

On the other hand, as a mode in which the inner tube 10 and the outer tube 20 are fixedly connected in the circumferential direction, for example, as shown in FIG. A groove 10a may be formed in the outer surface of the shaft 10 along the axial direction, and the fixing pin 24 may be fitted in the groove 10a of the inner tube. In this case, in order to provide a fluid passage for the gap between the inner pipe 10 and the outer pipe 20, a concave groove 20a is formed on the inner surface of the outer pipe 20 along the axial direction.
0a can be connected to the passage.

<Form when the "insertion pipe" is an improved rod 80> The improved rod 80 is a method of stirring and mixing while cutting the ground which has been injected with grout such as cement milk at a high pressure at a high pressure. This method is used for a stirring and mixing method such as a method of cutting the ground by injecting high-pressure water at a high pressure and stirring and mixing the cut soil and grout.

In this embodiment, the ground is injected with a grout such as cement milk at a high pressure at a high pressure, and the ground is stirred and mixed while being ground, and at this time, the method is used to entrain air. Also, without drilling the casing
The hole is drilled by itself.

More specifically, the base head 81 having the structure shown in FIG. 2 can be used. The intermediate pipe Z1 shown in FIG.
Although they are different in shape, they are basically the same in function as the intermediate tube Z in FIG. But,
In the intermediate pipe Z1 shown in FIG. 10, similarly to the structure of FIG. 5, the fixing pin 24A is configured to be fitted into the concave groove 10a of the inner pipe, and the rotational torque is transmitted to the inner pipe. .

On the other hand, the tip device Q shown in FIGS.
1 has a slightly complicated structure. This will be described briefly. The inner tube 83 and the outer tube 82 are connected and assembled concentrically with a gap and fixed in the circumferential direction on the same principle as the unit tube Z1. Inner tube 8 shown
The pieces 3 and the outer pipe 82 are connected to each other, but are shown by common hatching so that the distinction between the inner pipe 83 and the outer pipe 82 becomes clearer. On the contrary,
A flow path monitor 84 is provided at the distal end.

The outer pipe 82 has an inlet pipe 85, an intermediate pipe 86, and an outlet pipe 87. The intermediate tube 86 has a through hole 86a on the wall surface.

Drilling water DW used for drilling into the ground is sent through the inside of the inner pipe 83, and once goes out of the inner pipe 83 through the guide path 83 a at the tip end to be in contact with the outer pipe 82. Then, it passes through the gap, then passes between the distal end surface of the inner pipe 83 and the flow path monitor 84 to reach the center, and is discharged from the discharge port 84b toward the ground while pushing down the check valve 84a. I have.

On the other hand, a jet nozzle 90 is fixed to the inner pipe 83. The ejection nozzle 90 has a double structure, and the inside communicates with the center path of the inner pipe 83. Outside is inner tube 8
3 and the gap between the outer pipe 82. The outer pipe 82
The inside diameter of the intermediate pipe 86 is enlarged so that it can be used for the passage of the drilling water DW as described above. A sealing material 89 such as an O-ring is provided on the outer surface of the corresponding portion of the inner tube 83, and as shown in FIG. 12, when the inner tube 83 is retracted, the sealing material 89 makes contact with the inner surface of the intermediate tube 86. The space is sealed.

At the time of drilling / inserting the ground with the improved rod 80, the inner pipe 83 is at a position where it is pushed down as shown in FIG. 11, and in this state drilling water DW is pumped through the inner pipe 83.

When the improvement rod 80 reaches a predetermined depth, the inner pipe 83 is retracted as shown in FIG. Thus, the ejection nozzle 90 directly faces the outside through the through hole 86a for the first time.

After this operation, as shown in FIG. 12, a grout material G such as cement milk is injected at a high pressure through the inner flow path of the inner pipe 83 and the inside of the jet nozzle 90 toward the ground. At the same time, the air A is ejected from the outside of the ejection nozzle 90 toward the ground at high pressure through the gap between the inner pipe 83 and the outer pipe 82 and the guide path 83b. At this time, the improved rod 8
Ground improvement is performed while rotating the entirety (excluding the base head 81) around the axis and continuously or intermittently retreating.

As described above, the base head 81 and the unit tube Z1
By moving the group and each inner tube of the tip device Q1, the ejection nozzle 90 is exposed and concealed from the through hole 86a. The jet nozzle 90 needs to be concealed in order to prevent intrusion of the surrounding earth and sand at the time of drilling and inserting the ground with the improved rod 80, and for protection against damage.

[0061]

As described above, according to the present invention, the communication between the opening window and the inside of the inner pipe can be reliably switched in the ground insertion pipe such as a drain pipe or an improved rod. In addition, in the improvement at the position under the pressure of the groundwater, reliable construction can be performed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of an installation mode of an insertion tube.

FIG. 2 is a half sectional front view of a base head.

FIG. 3 is a longitudinal sectional view of a unit tube.

FIG. 4 is a cross-sectional view thereof.

FIG. 5 is a cross-sectional view of another example of a unit pipe.

FIG. 6 is a longitudinal sectional view of the tip device.

FIG. 7 is a longitudinal sectional view of the tip device having different circumferential positions.

FIG. 8 is a longitudinal sectional view of the tip device at the time of drainage.

FIG. 9 is an enlarged vertical sectional view of a main part.

FIG. 10 is a longitudinal sectional view of a unit pipe in the improved rod.

FIG. 11 is a longitudinal sectional view of a tip device of the improved rod.

FIG. 12 is a longitudinal sectional view of the distal end device of the improved rod when the inner tube is retracted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base inner pipe, 2 ... Base outer pipe, 3 ... 1st swivel, 4 ...
Bearing, 6 ... Second swivel, 7 ... Bearing, 8 ...
Connection screw, 9: return-type hydraulic piston, 10: inner tube, 10
F: female screw, 10M: male screw, 20: outer tube, 20F: female screw, 20M: male screw, 23: support tube (support portion), 24
... Fixing pin, 40 ... Inner tube, 50 ... Outer tube, 52a ... Open window (through hole), 60 ... Flow path monitor, 62 ... Nozzle body, 70
... Sludge pipe, 80 ... Improved rod, 82 ... Outer pipe, 83 ... Inner pipe, 86a ... Through hole (opening window), 90 ... Squirting nozzle, 10
0: Improved body, Q: Advanced equipment, R: Mud, W: Water, DW ...
Drilling water.

Continuing on the front page (72) Inventor Masakazu Iijima 2-5-3 Misaki-cho, Chiyoda-ku, Tokyo Teppei Construction Co., Ltd. (72) Inventor Koji Nakayama 4-20 Sendagaya, Shibuya-ku, Tokyo Nihon Sogo Waterproofing Co., Ltd. (72 ) Inventor: Takehiko 4-20 Sendagaya, Shibuya-ku, Tokyo Inside Japan Sogo Waterproofing Co., Ltd. (72) Inventor Norio Takahashi 4-20, Sendagaya, Shibuya-ku, Tokyo Inside Japan Sogo Waterproofing Co., Ltd. 2-30-18 Nishiaraihonmachi, Ward (56) References JP-A-4-347206 (JP, A) JP-A-7-138932 (JP, A) JP-A-6-185044 (JP, A) JP-A-8 -218759 (JP, A) JP-A-8-13467 (JP, A) JP-A-4-189916 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/12 102 E21B 7/18

Claims (4)

(57) [Claims] 1. An insertion tube in which an inner tube and an outer tube are assembled substantially concentrically is inserted into the ground, a base of the insertion tube is installed outside the ground, and a base and a tip of the insertion tube are connected to each other. An opening window is formed in a wall surface of a distal end portion of the outer tube, and the inner window and the opening window are configured to be able to communicate with each other at a distal end portion of the inner tube; When the position of the tube is fixed, the inner tube can be moved in the axial direction by an external force acting on the inner tube at the base portion, and communication between the opening window and the inside of the inner tube is made at a first position of this movement. There is blocked, configured of as communication between the opening window and the inner tube in the second position is achieved
In the inner pipe of the insertion pipe, a ground improvement fluid ejection nozzle communicating with the inside thereof is disposed facing outward, and in the state where the first position is taken, the ejection nozzle is connected to the outer pipe.
A ground improvement device, wherein the ejection nozzle faces the opening window in a state of being hidden by the second position and the ground improvement fluid is ejected from the ejection nozzle. 2. An insertion tube, in which an inner tube and an outer tube are substantially concentrically assembled, is inserted into the ground, and a base of the insertion tube is installed outside the ground. An opening window is formed on a wall surface of a distal end portion of the outer tube, and the inner tube and the opening window are configured to be able to communicate with each other at a distal end portion of the inner tube. In the position fixed state, the inner tube can be moved in the axial direction by an external force acting on the inner tube at the base portion, and communication between the opening window and the inside of the inner tube is made at the first position of this movement. Using an improvement device configured to prevent communication between the opening window and the inside of the inner pipe at the second position; insert an improvement rod of the ground into the ground, and move to the first position.
At one time, drilling water is pumped through the inner pipe and the opening
Do not drill to the specified depth while discharging from the tip side from the window.
The ground improvement rod is almost parallel to the ground improvement rod.
Insert the insertion tube toward the ground improvement area with the rod
Advance; ejection of ground improvement material into the ground through the ground improvement rod
Mud with the discharge of the ground improvement material into the ground
From the opening window in the state where the second position is taken.
A ground improvement method , wherein a fluid from the ground side is guided to the base side and discharged out of the ground. 3. An insertion tube in which an inner tube and an outer tube are assembled substantially concentrically is inserted into the ground, and the base of the insertion tube is installed outside the ground. An opening window is formed in a wall surface of a distal end portion of the outer tube, and the inner window and the opening window are configured to be able to communicate with each other at a distal end portion of the inner tube; When the position of the tube is fixed, the inner tube can be moved in the axial direction by an external force acting on the inner tube at the base portion, and communication between the opening window and the inside of the inner tube is made at a first position of this movement. And an improvement device configured so that communication between the opening window and the inside of the inner tube is achieved at the second position; a ground improvement fluid that communicates with the inside of the insertion tube is provided in the inner tube of the insertion tube. An ejection nozzle is disposed facing outward, taking the first position and With the ejection nozzle hidden in the outer tube, the insertion pipe is inserted into the ground, the second position is taken at a predetermined depth, and the ejection nozzle faces the opening window. A ground improvement method characterized by performing ground improvement by discharging a ground improvement material into the ground including ejection of a working fluid. 4. When the insertion pipe is inserted into the ground, when the insertion pipe is at the first position, drilling water is pumped through the inner pipe and cut to a predetermined depth while being discharged from a tip side from the opening window. The method for improving the ground according to claim 3, wherein the insertion pipe is inserted into the ground by making a hole.