JP2008202369A - Ground improvement method and ground improvement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground improvement method and a ground improvement device which can effectively discharge excess muddy water easily and at low cost. <P>SOLUTION: The ground improvement method comprises the first process of arranging a mud-discharge pipe 10 in the ground G to penetrate an improvement area A of which the ground is to be improved, the second process of connecting a supply pipe 30 used for supplying a conditioning material C to the improvement area A to one end of the mud-discharge pipe 10 and the third process of spraying the conditioning material C at high pressure onto the improvement area A through the medium of the supply pipe 30 while drawing the supply pipe 30 into the ground G by drawing the mud-discharge pipe 10 from the other end. The excess muddy water generated with the high-pressure spraying of the conditioning material C is taken into the mud-discharge pipe 10, and is discharged from the other end of the mud-discharge pipe 10. The ground improvement device using the above method is also disclosed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ground improvement method and a ground improvement device suitably used for the same, and more particularly to a ground improvement method and a ground improvement device suitably used for improvement of a ground below an existing structure or the like.

  The ground improvement method that uses high-pressure injection is conventionally used for boring in a vertically downward, horizontal, or slanted direction, and then installing an injection material consisting of water, air, solidified material, etc. at the tip of the drilling tube The method is performed by pulling out the monitor while performing high-pressure injection from the monitor.

However, the conventional ground improvement method for constructing vertically downward could not be adopted when improving the ground below the existing structure. Further, when the ground to be improved is relatively deep or wide in plan, the drilling distance to reach the ground to be improved is increased, which is inefficient.
In addition, the conventional ground improvement method for construction in the horizontal horizontal direction or the diagonal direction is suitable for improvement of the ground below the existing structure, but requires a shaft that reaches the same depth as the ground to be improved. Therefore, it has a problem that it takes time and cost to construct the shaft, and it is necessary to secure a relatively large site for forming this shaft.

  In order to avoid such problems, for example, Patent Document 1 and Patent Document 2 describe an improved construction method for improving the ground below an existing structure by applying a flexible boring.

This ground improvement method is performed according to the following procedure.
First, from the ground surface near the structure, start drilling diagonally downward toward the bottom of the structure, drill a predetermined section below the structure horizontally, then drill diagonally upward A boring hole that penetrates the ground below the existing structure is formed. Next, the ground below the existing structure is improved by piping an injection pipe to the borehole and injecting the improvement material into the surrounding ground via this injection pipe.

  In the ground improvement method employing such a conventional high-pressure injection, if the high-pressure improvement material C or the like is accumulated in the underground G, there is a risk of inducing an ejection to the ground. For this reason, as shown to Fig.4 (a), the method for discharging the excess mud water D along the drilling pipe (injection pipe) 110, or for discharging the excess mud water D as shown in FIG. By separately arranging the pipe line 120, a method of discharging the excess mud water D is adopted to reduce the pressure in the ground.

JP 2001-193050 A JP 2006-283298 A

However, the method of discharging the excess mud water D along the drilling pipe (injection pipe) 110 may not ensure the stability of the hole wall of the boring hole 101. If the hole wall of the boring hole 101 is damaged, there is a possibility that a stable mud discharge function cannot be secured.
Further, when the pipe 120 for discharging the surplus muddy water D is disposed, there is a problem that the cost and labor required for piping of the pipe 120 are increased.

  The present invention is intended to solve the above-described problems, and proposes a ground improvement method and a ground improvement device that can efficiently and efficiently drain excess mud water at low cost. The task is to do.

  In order to solve the above-described problems, the ground improvement method of the present invention includes a step of placing a sludge pipe in the excavation hole formed so as to penetrate the improvement region to be improved, and the improvement region. Connecting a supply pipe for supplying the improved material to one end of the mud pipe, and pulling the drain pipe from the other end side to draw the supply pipe into the ground, through the supply pipe And a step of high-pressure injection of the improved material into the improved region, and the excess mud water generated together with the high-pressure injection of the improved material is taken into the waste mud pipe, and the taken-in excess mud water is taken into the other end side of the exhaust mud pipe It is characterized by being discharged from.

  Further, another ground improvement method of the present invention includes a step of placing a supply pipe in the ground for supplying an improvement material to an excavation hole formed so as to penetrate an improvement region to be improved, Connecting the tip of the pipe to one end of the supply pipe, and pulling the drain pipe from the other end side into the ground while pulling the drainage pipe into the ground, the improvement material to the improvement region via the supply pipe A high-pressure injection of the improved material, the excess mud generated with the high-pressure injection of the improved material is taken into the drainage pipe, and the taken-up excess mud is discharged from the rear end side of the drainage pipe .

  According to such ground improvement method, excess mud water generated by high-pressure injection of the improved material is discharged using the drainage pipe, so that the high-pressure material accumulates in the ground, resulting in eruption to the ground. To prevent. In addition, by using a mud pipe for discharging the excess mud water, it is possible to stably discharge the excess mud water. Moreover, since it is not necessary to newly drill a hole for piping a pipe for discharging excess muddy water, the workability is excellent.

  In the ground improvement method, the drainage pipe and the supply pipe may be connected via an injection monitor. The injection monitor includes a discharge mud portion in which a discharge hole for taking in the excess mud water is formed and communicated with the discharge mud pipe, and an injection unit in which an injection hole is formed and connected to the supply pipe, The said mud drain part and the said injection part are parted through the inner wall. Since the mud drainage part and the injection part are divided via the inner wall, the excess mud water does not hinder the supply of the improved material by flowing into the supply pipe side, and the high pressure injection of the improved material and the surplus mud water Can be suitably discharged.

  Further, in the ground improvement method, the excavation hole is drilled downward from the ground, drilled in a horizontal direction at a predetermined depth, and then drilled upward after penetrating the improved region. May be formed. Such a ground improvement method is such that the other end side of the waste mud pipe is disposed at a position higher than the improvement region, so that the amount of the improvement material injected into the improvement region at a high pressure without using the waste mud control device. And the amount of excess muddy water discharged together with the high-pressure injection of the improved material is equalized.

  Further, the ground improvement device of the present invention is a mud pipe disposed in a drilling hole formed in the ground so as to penetrate the improved area to be ground improved, and one end attached to the tip of the mud pipe. An injection monitor disposed in the excavation hole in a state of being provided, and a supply pipe disposed in the excavation hole in a state of being connected to the other end of the injection monitor and supplying an improvement material to the injection monitor. The injection monitor includes a discharge mud portion that is formed with a discharge hole for taking in the excess mud water and communicates with the discharge mud pipe, and an injection unit that is formed with an injection hole and connected to the supply pipe. , And the drainage part and the injection part are separated through an inner wall.

  According to such a ground improvement device, the improvement material is discharged to the ground through the discharge mud pipe connected to the injection monitor for the high-pressure injection of the improvement material to the ground using the injection monitor. Ground deformation is prevented. Moreover, since excess muddy water is discharged | emitted via a mud discharge pipe, the hole wall of an excavation hole is not disturbed, but stable construction is attained.

  In the ground improvement device, the supply pipe is composed of an inner pipe made of a flexible pipe material for pumping the improvement material, and an outer pipe connected to the injection monitor and including the inner pipe. If so, the supply pipe can follow even the excavation hole having the curved portion. Further, since the inner tube is built in the outer tube, it does not break due to contact with the hole wall.

  Moreover, you may connect a suction device to the rear-end part (ground side edge part) of the said sludge pipe for the purpose of promotion of discharge | emission of excess mud water.

  In addition, about the drilling hole, a hole is drilled obliquely downward from the vicinity of the existing structure to a predetermined depth toward the lower side of the existing structure, and then in the lateral direction at the predetermined depth. If it is formed by drilling in a diagonally upward direction until it reaches the ground surface after drilling, it is preferable because the ground can be improved directly under the existing structure.

  With the ground improvement method of the present invention and the ground improvement device used therefor, it has become possible to efficiently and efficiently drain excess mud water at low cost.

Hereinafter, preferred embodiments of the present invention will be described.
Here, FIG. 1 is a side view showing an outline of the ground improvement device according to the present embodiment. FIG. 2 is a perspective view showing a supply pipe of the ground improvement device shown in FIG. Moreover, Fig.3 (a)-(d) is a side view which shows each construction step of the ground improvement method which concerns on this embodiment.

  As shown in FIG. 1, the ground improvement device 1 according to this embodiment includes a drainage pipe 10 disposed in a pilot hole (excavation hole) 2 formed in the ground (underground), and one end of the mud drainage. An injection monitor 20 disposed in the pilot hole 2 in a state of being attached to the tip of the pipe 10, and being disposed in the pilot hole 2 in a state of being connected to the other end of the injection monitor 20 and improving the injection monitor 20. And a supply pipe 30 for supplying C.

  As shown in FIG. 2, the mud discharge pipe 10 is a metal pipe material disposed in the pilot hole 2 together with the drilling of the pilot hole 2 by free boring. The material constituting the drainage pipe 10 is a material that can follow the shape of the pilot hole 2 formed in a curved state, and is a pushing force or a drawing force applied by the boring machine BM (see FIG. 3). However, the material is not limited as long as it has sufficient proof strength, and may be appropriately selected from known materials. Further, the inner diameter and thickness of the mud pipe 10 may be appropriately set according to the strength and soil quality of the ground G and the pressure and amount of surplus mud water assumed, and are not limited.

  In this embodiment, a suction device (not shown) for sucking the excess mud water D is connected to the rear end portion of the mud pipe 10. However, if the suction device is installed as necessary, Good.

  As shown in FIG. 2, the injection monitor 20 is a member that is inserted into a pilot hole 2 formed by free boring and injects the improvement material C at a high pressure toward the surrounding ground G inside the pilot hole 2. .

  One end of the injection monitor 20 is fixed to the mud pipe 10. A supply pipe 30 is connected to the other end of the injection monitor 20 via a rotary joint 40.

  As shown in FIG. 2, the injection monitor 20 is a cylindrical metal member, and is formed with discharge holes 21 and 21 for taking in excess mud water D and communicates with the discharge pipe 10. And an injection part 20b in which injection holes 22, 22, and 22 are formed and connected to the supply pipe 30, and these drainage part 20a and injection part 20b are divided through an intermediate wall 23. Yes.

  The injection part 20b of the injection monitor 20 has an inner diameter and an outer diameter equivalent to those of an outer pipe 31 to be described later, and the mud drain part 20a has an outer diameter at the tip that is equivalent to the outer diameter of the mud pipe 10. Thus, a taper is formed. Needless to say, when the outer diameters of the mud pipe 10 and the supply pipe 30 are equal, no taper is formed. Moreover, the material which comprises the injection monitor 20 is not limited, What is necessary is just to select and use from a well-known material suitably.

  In the injection monitor 20 according to the present embodiment, two discharge holes 21 for taking in the excess muddy water D are formed at positions facing each other of the mud portion 20a. The surplus mud water D flows out of the discharge hole 21 into the injection monitor 20 (the mud discharge part 20a) and then flows out to the mud pipe 10. Since the sludge part 20a and the spray part 20b of the spray monitor 20 are separated by the middle wall 23, the excess mud water D that has flowed into the sludge part 20a does not flow out to the supply pipe 30 side.

  In the present embodiment, the two discharge holes 21 are formed. However, the number of the discharge holes 21 is not limited, and depends on the amount of excess mud water D, the shape of the discharge holes 21, and the like. Thus, it may be set as appropriate so that the excess muddy water can be efficiently discharged. Further, in the present embodiment, the discharge hole 21 is formed in a circular shape, but it goes without saying that the shape of the discharge hole 21 may be an elliptical shape, a rectangular shape, or other polygonal shapes. Furthermore, the inner diameter (inner width) of the discharge hole 21 is not limited, and may be set as appropriate so that the excess mud water D can be discharged efficiently.

  The injection portion 20b of the injection monitor 20 is formed with three injection holes 22, 22, and 22 arranged in parallel for high-pressure injection of the improved material C supplied from the supply pipe 30 toward the surrounding ground G. ing. Inner pipes 22 a, 22 b, 22 c connected to the inner pipes 32 a, 32 b, 32 c of the supply pipe 30 are connected to the injection holes 22, 22, 22, and the high pressure of the improved material C fed from the supply pipe 30 is high. It is comprised so that injection can be performed.

  In the present embodiment, the three injection holes 22 are formed, but the number of the injection holes 22 is not limited to this, and depending on the type of the improved material C, the injection method, and the like, What is necessary is just to set suitably. Moreover, it is good also as a structure which carries out the high pressure injection in multiple directions by forming each injection hole 22 in the state which each has an angle. Needless to say, the arrangement of the injection holes 22 is not limited.

The supply pipe 30 is a pipe line for supplying the improvement material C to the injection monitor 20. In this embodiment, the supply pipe 30 is piped inside the outer pipe 31 as the outer shell and the outer pipe 31. It is comprised by the three inner pipes 32a, 32b, and 32c to pump.
The supply pipe 30 is connected to the end of the injection monitor 20 opposite to the mud pipe 10. In the present embodiment, a hydraulic material such as a cement-based improvement material is used as the improvement material C, and each of the inner pipes 32a, 32b, and 32c pumps cement, water, and an admixture, respectively. In addition, the material which comprises the improvement material C is not limited, What is necessary is just to select from a well-known material suitably according to a ground condition, the required improvement intensity | strength, etc., and to use.

  The material constituting the outer tube 31 is not limited as long as it is a material that can follow the shape of the pilot hole 2 formed in a curved shape, and may be appropriately selected from known materials. .

  Further, the inner pipe 32 is configured by a flexible pipe material (flexible pipe), and is configured to be able to follow the alignment of the pilot hole 2.

  The injection monitor 20 and the supply pipe 30 are connected via a rotary joint 40. As a result, the injection monitor 20 rotates with the rotation of the sludge pipe 10, whereas the supply pipe 30 does not rotate. Therefore, the supply pipe 30 is not subjected to stress during rotation, and is flexible. It becomes possible to comprise with a pipe material.

  The rotary joint 40 supplies the improvement material C pumped from the supply pipe 30 which is a fixed pipe to the injection monitor 20 which is a rotating body without leaking. The rotary joint 40 may be appropriately selected from known ones and used, and the configuration thereof is not limited. The rotary joint 40 may be used as necessary, and the rotary joint 40 is not necessarily used for the connection between the injection monitor 20 and the supply pipe 30.

  In the present embodiment, the supply pipe 30 is a pipe in which a plurality of inner pipes 32 are piped inside the outer pipe 31, but the configuration of the supply pipe 30 is not limited. A perforated tube or a multiple tube may be used. Needless to say, the number of the inner pipes 32 can be appropriately changed according to the type of the improved material C. Furthermore, as the improving material C, a single tube may be used when the material to be jetted onto the ground at high pressure is made of a premixed material or one kind of material. Moreover, the material which comprises the inner pipe | tube 32 is not limited, What is necessary is just to select and use from a well-known material suitably.

Next, the ground improvement method of this embodiment is demonstrated with reference to FIG.
As shown in FIG. 3, in the present embodiment, for the purpose of increasing the strength of the foundation ground of an existing structure K, the ground improvement is performed by the ground improvement method of the present invention for the improvement range directly below the structure K. explain. In addition, the shape, use, etc. of the structure K are not limited.

  The ground improvement method according to the present embodiment includes a drilling step in which the sludge pipe 10 is disposed in the ground G so as to penetrate the improvement area A to be improved, and a supply pipe for supplying the improvement material to the improvement area A The connecting step of connecting 30 to the tip (one end) of the mud pipe 10 and pulling out the mud pipe 10 from the rear end side to pull the supply pipe 30 into the ground, and to the improved region A through the feed pipe 30 And an injection step of high-pressure injection of the improved material C.

  The drilling step is a step of drilling the pilot hole 2 using a boring machine BM as shown in FIGS. The pilot hole 2 is formed so as to pass through the improved range A set below the existing structure K.

  The pilot hole 2 is drilled obliquely downward from the start pit S arranged in the vicinity of the existing structure K to a predetermined depth toward the lower side of the structure K, and is cut horizontally in the predetermined depth. After the hole is formed, it is formed in a state in which the improved range A below the structure K is passed by drilling in a diagonally upward direction until reaching the reaching pit T provided on the opposite side of the structure K.

  The pilot hole 2 is formed by pushing the mud pipe 10 provided with the excavation bit 11 at the tip while rotating it into the ground (in the ground G) via the boring machine BM. At this time, as the excavation bit 11 digs, the mud pipe 10 is connected at any time. In addition, the formation method, shape, etc. of the pilot hole 2 are not limited, and may be appropriately selected from known means.

  The connecting step is a step of connecting the supply pipe 30 via the injection monitor 20 to the tip of the exhaust pipe T side of the mud pipe 10 arranged so as to penetrate the improved region A by the drilling process.

  When the drilling of the pilot hole 2 is completed by the drilling process and the excavation bit 11 reaches the access hole T, the excavation bit 11 attached to the tip of the sludge pipe 10 is recovered as shown in FIG. The injection monitor 20 is attached to the tip of the mud discharge pipe 10. At this time, the supply pipe 30 is connected to the side opposite to the connection end of the sludge pipe 10 of the injection monitor 20.

In the injection process, the injection monitor 20 is inserted into the pilot hole 2 formed by the drilling process, and the improved material C is injected at a high pressure in the improved range A, thereby causing a predetermined location in the ground G (the improved range A). ) Is a step of forming the improved body 3.
At this time, surplus muddy water D generated along with the high-pressure injection of the improved material C is taken into the sludge pipe 10 via the jet monitor 20, and the taken-in surplus muddy water D is discharged from the start pit S side of the sludge pipe 10.

  In the connecting step, when the supply pipe 30 is connected to the tip of the mud pipe 10 via the jet monitor 20, the jet monitor 20 is pulled out by pulling out the mud pipe 10 from the start shaft S as shown in FIG. The supply pipe 30 is pulled into the pilot hole 2.

  Then, as shown in FIG. 3 (d), when the injection monitor 20 reaches the improvement range A, high-pressure injection of the improvement material C is performed toward the ground G. At this time, surplus muddy water D generated by high-pressure injection of the improved material C is discharged from the start shaft S via the mud pipe 10.

  As shown in FIG. 1, since the discharge holes 21, 21 communicating with the mud pipe 10 are formed in the injection monitor 20, the excess mud water D is discharged from the discharge holes 21, 21. It is taken into the inside of.

  In this embodiment, about the waste mud of the excess mud water D, the suction mud is promoted by performing vacuum suction from the start pit S side by the suction device. In addition, if the mud of the excess mud water D can be naturally drained by the pressure of the high pressure injection of the improvement material C, it is not necessary to perform vacuum suction.

  As described above, according to the ground improvement method and the ground improvement device of the present embodiment, it is possible to supply the high-pressure spray material corresponding to the curved hole formed by the flexible boring, and to efficiently drain the excess mud water D. It became possible to do.

  In other words, the excess mud water D generated by the high pressure injection of the improved material C is discharged using the mud pipe 10, so that the high pressure material accumulates in the ground and prevents the eruption to the ground. It is possible to perform safe construction.

  In addition, since the waste mud D of the surplus mud water D is used in connection with the drilling of the pilot hole 2, the labor for newly installing the exhaust pipe can be omitted, By discharging the excess mud water D through the pilot hole 2 along the mud pipe 10, the hole wall is not damaged.

  Insertion into the ground of the injection monitor 20 and the supply pipe 30 drilled in advance is performed by pulling out the sludge pipe 10 connected to the injection monitor 20, so that the supply pipe 30 is resistant to stresses such as propulsive force. Is never required. Therefore, it can be configured by a flexible tube material. Therefore, it is possible to follow the linear shape of the pilot hole 2 having a curved portion having a relatively large curvature.

  Moreover, since the discharge hole 21 connected with the mud pipe 10 is formed in the injection monitor 20, it is possible to discharge | emit the excess mud water D suitably.

  Regarding the construction of the pilot hole 2, a drilling hole is drilled obliquely downward from the start pit S provided in the vicinity of the existing structure K to a predetermined depth toward the lower side of the structure K, and in the horizontal direction at the predetermined depth. After drilling in the ground, it is formed by drilling diagonally upward until it reaches the ground reach mine T. Therefore, the ground G directly under the existing structure K is improved without affecting the structure K. Can be performed.

  Further, in the ground improvement method according to the present embodiment, the pilot hole 2 drills downward from the ground, drills in the horizontal direction at a predetermined depth, penetrates the improved range A, and then upwards. Since it is formed by drilling, the discharge port of the excess mud water of the mud pipe 10 (the other end of the mud pipe 10) is arranged at a position higher than the improved range A, and the mud control device is arranged. There is no need to do. In other words, the conventional horizontal jet grouting method uses the amount of excess mud water D discharged through the mud control device and the improved material to be injected in order to prevent the ground from rising and sinking due to the ground improvement. Whereas the amount of C was controlled to be equal, the ground improvement method according to the present embodiment is configured such that the discharge port of the excess mud water is disposed at a position higher than the improvement range A. Without using a control device, the amount of the improved material injected into the improved region at a high pressure and the amount of excess mud discharged together with the high pressure injection of the improved material become equal.

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, in the ground improvement method shown in the above embodiment, the pilot hole is formed via the drainage pipe, but the supply pipe for supplying the improvement material so as to penetrate the improvement region to be improved in the ground is provided. A pilot hole is formed by placing it in the ground, and the tip of the sludge pipe is connected to one end of this feed pipe, and then the feed pipe is pulled out from the other end side while the sludge pipe is drawn into the ground and supplied. It is good also as a structure which inject | pours a high pressure improvement material into an improvement area | region through a pipe | tube.

  In the above embodiment, the injection monitor is connected to the end of the exhaust pipe side of the exhaust pipe, and the injection monitor is drawn into the pilot hole while pulling out the exhaust pipe from the start pit side. It is good also as a structure which connects an injection monitor to a mine side edge part, and draws in from the arrival mine side.

  In the above embodiment, the drainage pipe is arranged together with the drilled pilot hole. However, the ground is improved by inserting the drainage pipe into the drilled pilot hole in a later work. You may arrange | position so that the improvement area | region which should be penetrated.

  In the said embodiment, although it was set as the structure which provides a discharge hole in an injection monitor, the formation location of a discharge hole is not limited, For example, you may form in the front-end | tip part of a sludge pipe.

  Moreover, in the said embodiment, although it was set as the structure which provides a start pit and an arrival mine on the ground surface, and forms the pilot hole which has a curved part, the horizontal direction which does not have a curved part using a shaft etc., for example The pilot hole may be drilled by boring, and the alignment of the pilot hole is not limited.

It is a side view which shows the outline | summary of the ground improvement apparatus which concerns on suitable embodiment of this invention. It is a perspective view which shows the supply pipe | tube of the ground improvement apparatus which concerns on suitable embodiment of this invention. (A)-(d) is a side view which shows each construction step of the ground improvement method which concerns on suitable embodiment of this invention. (A), (b) is a side view which shows a part of conventional ground improvement apparatus.

Explanation of symbols

1 Ground improvement device 2 Pilot hole (drilling hole)
DESCRIPTION OF SYMBOLS 3 Improved body 10 Drainage pipe 20 Injection monitor 20a Drainage part 20b Injection part 21 Discharge hole 22 Injection hole 23 Middle wall 30 Supply pipe 31 Outer pipe 32 Inner pipe (flexible pipe material)
A Improvement range C Improvement material D Excessive muddy water G Ground K Existing structure

Claims (7)

Placing the drainage pipe in the excavation hole formed so as to penetrate the improved area to be ground improved;
Connecting a supply pipe for supplying an improved material to the improved area to one end of the mud pipe;
And a step of high-pressure injection of the improvement material into the improvement region through the supply pipe while drawing the supply pipe into the ground by pulling out the drainage pipe from the other end side. ,
The surplus muddy water generated together with the high-pressure injection of the improved material is taken into the sludge pipe, and the surplus muddy water taken in is discharged from the other end side of the sludge pipe,
Ground improvement method. Disposing a supply pipe in the ground for supplying the improvement material to the excavation hole formed so as to penetrate the improvement region to be ground improved;
Connecting the tip of the drainage pipe to one end of the supply pipe;
And a step of high-pressure injection of the improvement material into the improvement region through the supply pipe while drawing the drainage pipe into the ground by pulling out the supply pipe from the other end side. ,
The surplus muddy water generated together with the high-pressure injection of the improved material is taken into the mud pipe, and the taken-up surplus muddy water is discharged from the rear end side of the mud pipe,
Ground improvement method. The drainage pipe and the supply pipe are connected via an injection monitor,
The injection monitor includes a discharge mud portion in which a discharge hole for taking in the excess mud water is formed and communicated with the discharge mud pipe, and an injection unit in which an injection hole is formed and connected to the supply pipe,
The drainage part and the injection part are separated through an inner wall,
The ground improvement method according to claim 1 or 2. The excavation hole is formed by drilling upward from the ground after drilling downward from the ground, penetrating the improved region by drilling in a horizontal direction at a predetermined depth,
Since the other end side of the sludge pipe is arranged at a position higher than the improved region, the amount of the improved material injected into the improved region at a high pressure and the high pressure of the improved material without using the waste control device. The amount of surplus muddy water discharged with injection is equalized,
The ground improvement method according to any one of claims 1 to 3. A sludge pipe placed in a borehole formed in the ground so as to penetrate the improved area to be ground improved,
A spray monitor disposed in the excavation hole with one end attached to the tip of the mud pipe,
A ground improvement device comprising: a supply pipe that is arranged in the excavation hole and connected to the other end of the injection monitor and supplies the injection monitor with an improvement material,
The injection monitor includes a discharge mud portion in which a discharge hole for taking in the excess mud water is formed and communicated with the discharge mud pipe, and an injection unit in which an injection hole is formed and connected to the supply pipe,
The drainage part and the injection part are separated through an inner wall,
Ground improvement device.   The supply pipe is made up of an inner pipe made of a flexible pipe material for pumping the improved material, and an outer pipe connected to the injection monitor to house the inner pipe. The ground improvement device according to claim 5.   The ground improvement device according to claim 5 or 6, wherein a suction device is connected to a rear end portion of the mud pipe.

Images