JP2003138553A - Soil improvement method and its monitor mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soil improvement method eliminating an uncut part from being formed in the lower part and the upper part of a cut area and preventing the upper part of the cut area from being uselessly enlarged and to provide its monitor mechanism. SOLUTION: The monitor mechanism 4 with multiple cutting blades 6 is provided in the lower part of a hardening material injection tube 2, the hardening material injection tube 2 is rotated by a boring device to form a bored hole of a target depth under the ground, a jet flow G of cutting fluid is jetted from the tip of the cutting blades 6, and the hardening material injection tube 2 is raised while being rotated to cut the circumferential ground of the cutting blades 6 by the jet flow G. Two or more jet flows G and G are crossed and collided with each other to limit its cutting range, and unhardened piles in the cut area are hardened to form a foundation structure under the ground. The multiple cutting blades 6 are in an approximately same horizontal plane and the two or more jet flows G and G are crossed and collided with each other on an approximately same horizontal plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method for constructing an underground pile to be a basic structure such as a water stop wall, an underground continuous wall or a foundation ground, and a monitor mechanism applied to the method.

[0002]

2. Description of the Related Art As a ground improvement method of this type, a method disclosed in, for example, JP-A-7-252823 is known. FIG. 6 is a schematic diagram of the ground improvement method. In this ground improvement method, a swivel 3 is provided above the hardening material injection pipe 2, a monitor mechanism 4 having upper and lower cutting blades 6 is provided below the hardening material injection pipe 2, and the hardening material is injected by the boring device 1. The pipe 2 is swirled to form a perforation 12 to a target depth in the ground, and then a jet G of a hardening material g is jetted from the tip of the cutting blade 6 to pull up the hardening material injection pipe 2 while swirling. As a result, the ground around the cutting blade 6 is cut by the jet G and the jet G above and below is cut.
This is a method of forming the foundation structure 14 in the ground by intersecting and colliding G to limit the cutting range and hardening the uncured pile P in the cutting area 13.

According to this ground improvement method, the upper and lower jets G
・ Because G is crossed and collided to limit the cutting range,
By reducing the discharge amount of the jet G and increasing the discharge pressure, there is an advantage that the target range can be cut in a short time, and the consumption amount of the hardening material g and the sludge discharge amount are greatly reduced. ,
There is room for improvement in the following points.

In the above-mentioned prior art, since the upper and lower jets G are made to intersect and collide with each other to limit the cutting range, FIG.
As shown in FIG. 3, a truncated cone-shaped uncut portion is formed in the lower portion or the upper portion of the cutting area 13. Further, for example, when excavating the lower side of the existing floor structure, the upper jet flow G of the upper and lower jets G is blocked by the floor structure, so that the cutting area 1
The upper part of 3 will unnecessarily expand.

The present invention has been made in view of the above circumstances, and an object thereof is to improve the ground without forming uncut portions in the lower and upper portions of the cutting area or unnecessarily expanding the upper portion of the cutting area. It is to provide a construction method and a monitoring mechanism applied to it.

[0006]

In order to solve the above problems, the present invention is configured as follows. That is, claim 1
In the invention described in 1., the boring machine 1 is provided with a monitor mechanism 4 having a plurality of cutting blades 6 provided below a hardening material injection pipe 2.
To swirl the hardening material injection pipe 2 to form a perforation 12 to a target depth in the ground, and then jet a jet G of cutting fluid from the tip of the cutting blade 6 to swivel the hardening material injection pipe 2. By pulling up while cutting the ground around the cutting blade 6 with the jet flow G, the cutting range is restricted by intersecting and colliding two or more jets G, G, and the cutting area 1
A ground improvement method for forming a foundation structure 14 in the ground by hardening the uncured pile P of No. 3, in which the plurality of cutting blades 6 are provided in substantially the same horizontal plane, and two or more jets G
The feature is that G is made to intersect and collide in substantially the same horizontal plane.

According to the second aspect of the present invention, a plurality of cutting blades 6 for ejecting a jet G of cutting fluid from the tip are provided so that two or more jets G can intersect and collide with each other to limit the cutting range. The monitoring mechanism configured as described above is characterized in that the plurality of cutting blades 6 are provided in substantially the same horizontal plane so that two or more jets G, G intersect and collide in the substantially same horizontal plane.

According to a third aspect of the present invention, a boring device is provided with a monitor mechanism 4 having a plurality of cutting blades 6 and a plurality of jet pipes 8 for jetting a jet G of cutting fluid below the hardening material injection pipe 2. 1, the hardening material injection pipe 2 is swung to form a perforation 12 to a target depth in the ground, and then a jet G of cutting fluid is jetted from the tip of the injection pipe 8 to swivel the hardening material injection pipe 2. While pulling up, the jet G
The ground around the cutting blade 6 is cut with, and the cutting range is limited by intersecting and colliding two or more jets G
A ground improvement method for forming a foundation structure 14 in the ground by hardening the uncured pile P in the cutting area 13, in which the plurality of injection pipes 8 are substantially formed within the turning radius R of the cutting blade 6. Two or more jets G are provided in the same horizontal plane, and the cutting blades 6 are provided at least on the lower side of the injection pipe 8.
-Characteristics are that G intersects and collides in substantially the same horizontal plane.

According to a fourth aspect of the invention, a plurality of cutting blades 6 and a plurality of injection pipes 8 for ejecting a jet G of cutting fluid from the tip end are provided.
Is a monitor mechanism configured to cross and collide two or more jets G and G to limit the cutting range thereof, and the plurality of injection pipes 8 within the turning radius R of the cutting blade 6.
Are provided in substantially the same horizontal plane, and the cutting blade 6 is provided at least on the lower side of the injection pipe 8 to provide two or more jets G.
It is characterized in that G is configured to intersect and collide in substantially the same horizontal plane.

According to a fifth aspect of the present invention, in the monitor mechanism according to the second or fourth aspect, a reaction force receiving member 10 is provided on an upper portion of the monitor main body 5, and the reaction force receiving member 10 is used. It is configured to receive the jet reaction force of the jet flows GG in the bore 12 according to claim 1 or claim 3.

[0011]

According to the inventions of claims 1 to 4,
Since the plurality of cutting blades 6 or the plurality of jet pipes 8 are provided in substantially the same horizontal plane and two or more jets G, G intersect and collide with each other in the substantially same horizontal plane, the cutting area 1 is provided as in the conventional example.
There is no frustoconical uncut portion in the lower and upper parts of 3, and the upper part of the cutting area 13 will not unnecessarily expand even when the lower ground of the existing floor structure is cut by the jet flow.

According to the fifth aspect of the present invention, the reaction force receiving member 10 is provided on the upper part of the monitor mechanism, and the reaction force receiving member 10 receives the jet reaction force of the jet G in the bore 12. Therefore, when jetting the jet G of cutting fluid to one side and pulling up the hardening material injection pipe 2 while swiveling, there is no risk that the swirl center of the jet G of the cutting fluid shifts. As a result, it is possible to form an even circular cutting area in plan view, and thus an even circular basic structure.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a monitor mechanism according to a first embodiment of the present invention, FIG. 1 (A) is an elevation view of the monitor mechanism, and FIG. 1 (B) is a plan view of the monitor mechanism.

As shown in FIGS. 1 (A) and 1 (B), the monitor mechanism 4 includes a monitor main body 5 connected to the lower portion of the hardening material injection pipe 2 and projections from the monitor main body 5 in the radial direction of rotation. The upper cutting blade 6a and the lower cutting blade 6b, and the lower cutting bit 10 provided at the lower portion of the monitor body 5, and the jet of the hardening material g as cutting fluid from the tip of the upper cutting blade 6a. G is ejected, and these jets G are made to intersect and collide within substantially the same horizontal plane.

The hardening material injection pipe 2 is composed of a double tube rod, and the hardening material injection pipe 2 and the monitor body 5 have a hardening material jet passage (not shown) formed along the axis thereof and the jet passage. And an air jet passage (not shown) formed in a ring shape on the outer side of. Further, a jet nozzle 7 for jetting a hardening material and air is provided at the tip of the upper cutting blade 6a, and two jets G, G jetted from the adjacent cutting blades 6a intersect and collide in substantially the same horizontal plane. By doing so, the cutting range of the ground is limited.

Each of the cutting blades 6a and 6b is provided with a plurality of excavating bits 9 on its lower surface, and is used to swivel the cutting blades 6a and 6b to form a perforation 12 to a target depth in the ground. . Further, the injection nozzle 7 is formed with a hardening material injection hole at the center and an air injection hole around it, so that the jet G of the hardening material g is guided by the injection air A around it to increase the flight distance. Is configured.

FIG. 1C shows a modified example of the above-mentioned monitor mechanism. In this modified example, three cutting blades 6a are provided in substantially the same horizontal plane, and the hardening material jets from the tip of each cutting blade 6a. G is ejected, and the three jets G are configured to intersect and collide within substantially the same horizontal plane.

2 (a) to 2 (d) are schematic views showing the procedure of the ground improvement method according to the present invention. FIG. 2 (a) is a boring step by a cutting blade, and FIG. 2 (b) is bentonite muddy water. An injection test with a jet W of w, FIG. 2C is a formation process, and FIG.
(D) shows a hole filling process, respectively. Hereinafter, this ground improvement method will be described with reference to FIGS.

A. Drilling step << Fig. 2 (a) >> In the drilling step, the boring device 1 is installed on the ground,
Bentonite muddy water w and air a are injected from the swivel 3 connected to the upper end of the hardening material injection pipe 2, and the hardening material injection pipe 2 is lowered while being driven by the boring device 1 to be connected to the lower part of the hardening material injection pipe 2. Bentonite muddy water w and air a are jetted from the lower portion 10 of the monitor mechanism 4 which has
The holes 6 having a predetermined depth are formed by rotating a and 6b. At this time, the bentonite muddy water W is recycled.

B. Injection test << Fig. 2 (b) >> In the injection test, a steel ball is put into the hardening material injection pipe 2, the muddy water discharge hole of the lower portion 10 of the monitor mechanism 4 is closed, and the hardening material injection pipe 2 is swung. Meanwhile, the cutting blade 6
A jet W of muddy water and air is continuously jetted from the tip of a as cutting fluid to cut the ground around it. At this time,
The muddy water jet W ejected from the tip of each cutting blade 6a intersects and collides in substantially the same horizontal plane. If this injection test is successful, the muddy water w injected from the swivel 3 is switched to the hardening material g and the creation process is started.

C. Creation step << Fig. 2 (c) >> In the creation step, the boring device 1 is operated to pull up the hardening material injection pipe 2 while swirling and driving, so that it is continuously ejected at a high pressure from the tip of the upper cutting blade 6a. Curing material g
And the ground of the outer peripheral area is cut by the jet G of high pressure air a,
An uncured pile P is created in the cutting area 13. At this time, a plurality of jets G intersect and collide with each other to limit the cutting range of the ground. By the way, the discharge pressure of the curing material is 10
100MPa, discharge amount from one nozzle is 40-300
1 / min, the discharge pressure of compressed air is set to 0.6 to ³ MPa, and the discharge amount is set to 1.0 to 10.0 m ³ / min.

At this time, the jet G of the hardened material g is generated by the cutting blade 6
Attenuation is reduced by the length of a, and the ground is largely cut by being guided by the blast air A and flying farther, while the cutting blades 6a and 6b and the jet G swirl to harden the material g and cutting mud. Knead. As a result, a large uncured pile P can be created, which in turn shortens the time for creating the substructure 13.

The surplus sludge 15 is pushed up by the jetting hardening material and air, and is discharged to the ground through the perforations 12. This sludge 15 is removed by a sludge pump 16. When the formation of the target range is completed, the supply of the hardening material g and the air a is stopped.

D. Hole filling step << Fig. 2 (d) >> In the hole filling step, the hardening material injection pipe 2 is pulled out to the ground, and the inside of the pipe is washed with clean water. Then, if necessary, the perforation 12 is filled. Then, it moves to the next construction point and the uncured pile P is formed in the soil by the same procedure. This uncured pile P
The foundation structure 14 is formed in the ground by hardening.

FIG. 3 is a view corresponding to FIG. 1 of the monitor mechanism according to the second embodiment of the present invention. The monitor mechanism 4 includes upper and lower cutting blades 6a and 6b and those cutting blades 6a.
-It is located in the middle of 6b and is within the radius of gyration R of the cutting blades 6a and 6b, and is provided with four injection pipes 8 provided in substantially the same horizontal plane, and two adjacent jets G-G are substantially the same. It is configured to intersect and collide in the horizontal plane to limit the cutting range.

In this embodiment, the injection pipe 8 is positioned in the middle of the cutting blades 6a and 6b so that the injection pipe 8 is not subjected to an unnecessary cutting load in the above-described drilling step << FIG. 2 (a) >>. It was done. Therefore, if the cutting blade 6 is provided at least on the lower side of the injection pipe 8,
The above intent is achieved. In addition, the other points are configured similarly to the first embodiment.

FIG. 4 (A) is a plan view of a monitor mechanism according to the third embodiment of the present invention, and FIG. 4 (B) is a schematic view of a forming process by the monitor mechanism. In this embodiment, the reaction force receiving member 10 is provided on the upper portion of the monitor body 5 in the first embodiment or the second embodiment, and the reaction force receiving member 10 causes the jet flow G to be generated in the bore 12. It is configured to receive the injection reaction force. The other points are the same as those of the first or second embodiment.

The above-described structure prevents the center of swirling from shifting to the opposite side by the jet G when the hardening material injection pipe 2 is swung up and pulled up while jetting the jet G of hardening material to one side. Is intended. This makes it possible to form a circular cutting area 13 that is uniform in a plan view. In this embodiment, a pair of left and right reaction force receiving members 10.1
However, this is because the rotational balance of the monitor mechanism 4 is taken into consideration, and at least one that receives the jet reaction force of the jet flows G, G is sufficient.

FIG. 5 (A) is a plan view of a monitor mechanism according to the fourth embodiment of the present invention, and FIG. 4 (B) is a schematic view of a forming process by the monitor mechanism. In this embodiment, in the first embodiment or the second embodiment, the hardening material injection pipe 2 is configured by a triple pipe rod, and high-pressure water (including high-pressure muddy water w) is used as the cutting fluid, so that the jet G The surrounding ground is cut by, and the jet G of the hardening material g is jetted from the jet nozzle opened in the lower part of the monitor body 5 to knead it with the cutting mud to form the uncured pile P.

According to the ground improvement method of the present invention, the two jets G are made to intersect each other in substantially the same horizontal plane, thereby eliminating the conventional uncut portion of the truncated cone shape which can be formed in the lower and upper portions of the cutting area. Even when the lower ground of the floor structure is cut with a cross jet, it is possible to prevent the upper part of the cutting area from unnecessarily expanding.

The present invention can be implemented with appropriate modifications, for example, as described below. In the above-described embodiment, an example in which the periphery of the jet G of cutting fluid is guided by the jet air A is used. There is no problem even if the guide by the injection air A is omitted.

[Brief description of drawings]

1 shows a monitor mechanism according to a first embodiment of the present invention, FIG. 1 (A) is an elevation view of the monitor mechanism, FIG.
FIG. 3B is a plan view of the monitor mechanism, and FIG. 3 is a plan view showing a modified example of the monitor mechanism.

2 (a) to 2 (d) are schematic views showing the procedure of the ground improvement method according to the present invention.

FIG. 3 is a view corresponding to FIG. 1 of a monitor mechanism according to a second embodiment of the present invention.

FIG. 4 (A) is a plan view of a monitor mechanism according to a third embodiment of the present invention, and FIG. 4 (B) is a schematic view of a forming process by the monitor mechanism.

5 (A) is a plan view of a monitor mechanism according to a fourth embodiment of the present invention, and FIG. 5 (B) is a schematic view of a forming process by the monitor mechanism.

FIG. 6 is a schematic diagram of a ground improvement method according to a conventional example.

[Explanation of symbols]

2 ... Curing material injection pipe, 4 ... Monitor mechanism, 5 ... Monitor main body, 6 / 6a / 6b ... Cutting blade, 7 ... Injection nozzle, 8 ... Injection pipe, 13 ... Cutting area, 14 ... Basic structure, G ... Cutting Liquid jet, g ... Cutting liquid (hardening material), w ... Cutting liquid (muddy water), P
… Unhardened pile.

Claims (5)

[Claims] 1. A hardener injection pipe (2) is provided with a monitor mechanism (4) having a plurality of cutting blades (6) below, and the hardener injection pipe (2) is swung by a boring device (1). Forming a perforation (12) to a target depth in the ground, then jetting a jet (G) of cutting fluid from the tip of the cutting blade (6),
By pulling up the hardening material injection pipe (2) while rotating it, the ground around the cutting blade (6) is cut by the jet flow (G) and two or more jet flows (G ・ G) are crossed.
Limit the cutting range by colliding and the cutting range (13)
A ground improvement method for forming a foundation structure (14) in the ground by hardening an uncured pile (P) of No. 1, wherein the plurality of cutting blades (6) are provided in substantially the same horizontal plane, and two or more are provided. The ground improvement method characterized by intersecting and colliding the jets (G ・ G) in the same horizontal plane. 2. A plurality of cutting blades (6) for ejecting a jet (G) of cutting fluid from the tip are provided, and two or more jets (G, G) are intersected and collided to limit the cutting range. A monitor mechanism configured such that the plurality of cutting blades (6) are provided in substantially the same horizontal plane so that two or more jets (G, G) intersect and collide in the substantially same horizontal plane. Monitor mechanism. 3. A monitor mechanism (4) having a plurality of cutting blades (6) and a plurality of jet pipes (8) for jetting a jet (G) of cutting fluid is provided below the hardening material injection pipe (2). , The boring device (1) swirls the hardening material injection pipe (2) to form a perforation (12) to a target depth in the ground, and then a jet of cutting fluid (G) from the tip of the injection pipe (8). Squirt out,
By pulling up the hardening material injection pipe (2) while rotating it, the ground around the cutting blade (6) is cut by the jet flow (G) and two or more jet flows (G ・ G) are crossed.
Limit the cutting range by colliding and the cutting range (13)
Is a ground improvement method for forming a foundation structure (14) in the ground by hardening the uncured pile (P) of the cutting blade (6), wherein the plurality of injections are made within the turning radius (R) of the cutting blade (6). The pipe (8) is provided in substantially the same horizontal plane, and the cutting blade (6) is provided at least on the lower side of the injection pipe (8),
A ground improvement method characterized by intersecting and colliding two or more jets (G, G) in substantially the same horizontal plane. 4. A plurality of cutting blades (6) and a plurality of injection pipes (8) for ejecting a jet (G) of cutting fluid from the tip are provided.
A monitor mechanism configured to limit the cutting range by intersecting / colliding the jets (G / G) described above, wherein the plurality of injection pipes (R) are provided within the turning radius (R) of the cutting blade (6). 8) is provided in substantially the same horizontal plane, and the cutting blade (6) is provided at least on the lower side of the injection pipe (8),
A monitor mechanism characterized in that two or more jets (G, G) intersect and collide in substantially the same horizontal plane. 5. The monitor mechanism according to claim 2 or 4, wherein a reaction force receiving member (10) is provided on an upper portion of the monitor body (5), and the reaction force receiving member (10) is used. A monitor mechanism, characterized in that it is configured to receive the jet reaction force of the jet flow (GG) in the perforation (12) according to claim 1 or claim 3.